ISSN NUMBER: 1938-7172
Issue 5.6 VOLUME 5 | NUMBER 6

Editor:
Michael A. Fiedler, PhD, CRNA

Contributing Editors:
Penelope S Benedik, PhD, CRNA, RRT
Mary A Golinski, PhD, CRNA
Gerard Hogan Jr., DNSc, CRNA
Alfred E Lupien, PhD, CRNA
Lisa Osborne, PhD, CRNA
Dennis Spence, PhD, CRNA
Cassy Taylor, DNP, DMP, CRNA
Steven R Wooden, DNP, CRNA

Guest Editor:
Amy Pfeil Neimkin, DNP, MBA, CRNA

Assistant Editor
Jessica Floyd, BS

A Publication of Lifelong Learning, LLC © Copyright 2011

New health information becomes available constantly. While we strive to provide accurate information, factual and typographical errors may occur. The authors, editors, publisher, and Lifelong Learning, LLC is/are not responsible for any errors or omissions in the information presented. We endeavor to provide accurate information helpful in your clinical practice. Remember, though, that there is a lot of information out there and we are only presenting some of it here. Also, the comments of contributors represent their personal views, colored by their knowledge, understanding, experience, and judgment which may differ from yours. Their comments are written without knowing details of the clinical situation in which you may apply the information. In the end, your clinical decisions should be based upon your best judgment for each specific patient situation. We do not accept responsibility for clinical decisions or outcomes.

Table of Contents

NEUROSURGICAL ANESTHESIA
  Conscious sedation versus general anesthesia during endovascular therapy for acute anterior circulation stroke: preliminary results from a retrospective, multicenter study
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PHARMACOLOGY
The effect of suggestion on unpleasant dreams induced by ketamine administration
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Complications associated with the administration of dantrolene 1987 to 2006: a report from the North American Malignant Hyperthermia Registry of the Malignant Hyperthermia Association of the United States
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A randomised comparison of intravenous remifentanil patient-controlled analgesia with epidural ropivacaine/ sufentanil during labour
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POLICY, PROCESS, & ECONOMICS
The $17.1 billion problem: the annual cost of measurable medical errors
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REGIONAL ANESTHESIA
Caudal normal saline injections for the treatment of post-dural puncture headache
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TRAUMA
Balanced massive transfusion ratios in multiple injury patients with traumatic brain injury
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Attention subscribers licensed in Alabama, Alaska, Idaho, Kentucky, Nevada, and New Mexico:

This issue contains 1 PHARMACOLOGY specific CE credit.


Neurosurgical Anesthesia
Conscious sedation versus general anesthesia during endovascular therapy for acute anterior circulation stroke: preliminary results from a retrospective, multicenter study

Stroke 2010;41:1175-9

Abou-Chebl A, Lin R, Hussain MS, Jovin TG, Levy EI, Liebeskind DS, Yoo AJ, Hsu DP, Rymer MM, Tayal AH, Zaidat OO, Natarajan SK, Nogueira RG, Nanda A, Tian M, Hao Q, Kalia JS, Nguyen TN, Chen M, Gupta R


Abstract

Purpose The purpose of this study was to compare the use of general anesthesia to conscious sedation for acute stroke endovascular interventions by determining differences in complication rates and clinical outcomes.

 

Background Endovascular therapy or intra-arterial therapy for severe acute ischemic stroke (AIS) has been proven effective for middle cerebral artery occlusion. The effects of devices and pharmacologic agents have been well reported. The choice of anesthetic for intra-arterial therapy has received little attention in the literature. General anesthesia (GA) is often preferred to immobilize the patient and facilitate imaging while reducing the risk of vessel injury due to movement. General anesthesia also provides the ability to facilitate blood pressure control and to ensure adequate ventilation, airway protection, and patient comfort. Conscious sedation (CS) has the advantage of allowing intermittent neurologic assessment during the procedure and may reduce delay to treatment. The optimal type of anesthesia for intra-arterial therapy for acute ischemic stroke has not been identified and is often solely operator preference based on experience and/or comfort.

 

Methodology The authors conducted a retrospective study of data from 12 stroke centers which included the following data:

  • de-identified demographic variables
  • National Institutes of Health Stroke Scale (NIHSS) score
  • intravenous tissue-type plasminogen activator use
  • use of general anesthesia
  • time to groin puncture
  • location of thrombus
  • recanalization grade
  • time to recanalization
  • postprocedural hemorrhage
  • 90-day clinical follow-up

 

Patients included had anterior circulation acute ischemic stroke treated with endovascular therapy between 2005 and 2009. A total of 980 patients met inclusion criteria and had 90-day follow-up data. Good outcomes were defined as a modified Rankin Score ≤ 2 (see chart below). The data was collected from each center’s database and were sent to the coordinating center for analysis. Because it was a retrospective study, the reason for intubation and general anesthesia versus conscious sedation was not known for each case. The authors used univariate analysis to compare patients in the two groups and a binary logistic-regression model to determine independent predictors of poor outcome and mortality. A separate analysis was performed to remove clot location as a potential confounder.

 

Result The mean age was 66 years with a median NIHSS score of 17. Successful recanalization occurred in 68% of patients undergoing intra-arterial therapy and 37% achieved a good outcome. The mortality rate was 31% with a symptomatic hemorrhage rate of 9.2%. The total number of patients placed under general anesthesia was 428 (44%) and these patients were more likely to have carotid terminus occlusions and higher baseline NHISS scores than conscious sedation patients. There was, however, no significant difference in the time to treatment (306 v. 296 minutes, P < 0.09) and the rates of asymptomatic or symptomatic hemorrhage. General anesthesia was found to have an independent association with both poor clinical outcomes and a higher risk of mortality.  To control for the imbalance of patients in the general anesthesia group with carotid terminus occlusions and higher NIHSS scores, a separate analysis was performed for patients presenting solely with isolated M1 middle cerebral artery occlusions. This group was balanced between general anesthesia and conscious sedation in NIHSS scores. After controlling for age, NIHSS score, time to groin puncture, time to recanalization, recanalization status, and presence of hemorrhage, the general anesthesia group still was at a significantly higher risk of poor outcome (odds ratio (OR)=2.33; 95% CI, 1.54 to 3.92; P<0.0001).

 

Conclusion The authors concluded that conscious sedation appeared to be as safe as general anesthesia during intra-arterial therapy for anterior circulation acute ischemic stroke in terms of time to treatment and risk of hemorrhage. Conscious sedation appeared to be associated with a higher probability of good clinical outcomes.

 

Comment

The type of sedation/anesthesia used in acute stroke interventions by neurointerventional practitioners varies greatly. In the above study, the 12 stroke centers participating varied in the use of general anesthesia from 0% (0/32, University of Louisville) to 100% (89/89, Massachusetts General Hospital). These data should at least raise questions about the type of anesthesia used during acute stroke interventions. Of interest is a retrospective review of intubated (general anesthesia) versus nonintubated (conscious sedation) patients during intra-arterial therapy for acute ischemic stroke of the proximal middle cerebral artery also published in Stroke.1 The patients included in this small review were intubated specifically for the procedure and there were no other significant differences between the groups. The procedures were performed at the same center with the same interventions by two experienced interventionalists. They found that nonintubated patients had lower infarct volumes, lower mortality, and better outcomes. Taken together, the preliminary data from these two studies can at least confirm that conscious sedation does not lead to a higher incidence of vessel injury and subsequent poor clinical outcomes and may be associated with a higher probability of good clinical outcomes.

 

In a retrospective review comparing general anesthesia and conscious sedation in patients undergoing craniotomy for supratentorial glioma resection in the Journal of Neurosurgery,2 the cohort groups were not statistically different in terms of postoperative neurological deficits. Patients from both cohorts suffered mild postoperative worsening of previous neurological deficits or the occurrence of new deficits. The significant difference between the two groups was length of hospital stay – the conscious sedation group had a much shorter post-ICU inpatient stay.

 

This study helps to describe the differences in outcomes in endovascular stroke therapy with general anesthesia versus conscious sedation as an anesthetic choice. As clinicians, however, we may need to consider not only the choice of general anesthesia or conscious sedation but the management of these techniques as well.

Amy Pfeil Neimkin, DNP, MBA, CRNA


1. Jumaa MA, Zhang F. Ruiz-Ares G. et al. Comparison of safety and clinical and radiographic outcomes in endovascular stroke therapy for proximal middle cerebral artery occlusion with intubation and general anesthesia versus the nonintubated state. Stroke. 2010;41:1180-1184.

2. Peruzzi P, Bergese SD, Viloria A. et al. A retrospective cohort-matched comparison of conscious sedation versus general anesthesia for supratentorial glioma resection. J Neurosurg. 2011;114:633-639.


 

Modified Rankin Scale

0

No symptoms at all

1

No significant disability despite symptoms; able to carry out all usual duties and activities

2

Slight disability; unable to carry out all previous activities, but able to look after own affairs without assistance

3

Moderate disability; requiring some help, but able to walk without assistance

4

Moderately severe disability; unable to walk without assistance and unable to attend to own bodily needs without assistance

5

Severe disability; bedridden, incontinent and requiring constant nursing care and attention

6

Dead

Provided by the Internet Stroke Center — www.strokecenter.org

 


© Copyright 2011 Anesthesia Abstracts · Volume 5 Number 6, June 30, 2011




Pharmacology
The effect of suggestion on unpleasant dreams induced by ketamine administration

Anesth Analg 2011;112:1082-5

Cheong SH, Lee KM, Lim SH, Cho KR, Kim, MH, Ko MJ, Shim JC, Oh MK, Kim YH, Lee SE


Abstract

Purpose The purpose of this study was to determine if positive suggestion effected the incidence of recall of unpleasant dreams after administration of ketamine for sedation.

 

Background Ketamine is associated with unpleasant dreams and emergence reactions in 11% to 53% of patients. The use of positive suggestion has been associated with a decrease in adverse unpleasant dreams after ketamine administration.

 

Methodology This was a prospective, randomized investigation of 125 patients undergoing spinal anesthesia for surgical procedures of the lower extremity, genitals, or perianal area with ketamine 0.6 mg/kg for sedation. Patients were randomized to a positive suggestion group or control group. No sedatives were administered within 12 hours of surgery and no premedication was administered. Patients completed the State Trait Anxiety Inventory (STAI) preoperatively. In the operating room spinal anesthesia was performed with 0.5% bupivacaine by an anesthesia provider blinded to group assignment. After confirmation of adequate surgical anesthesia, patients in the positive suggestion group were told, “After being treated with this drug, you will have very good dreams.” Patients in the control group were told, “You will be given a sedative drug before the operation, and then you will fall asleep.” Next all patients were administered ketamine 0.6 mg/kg. Loss of consciousness was determined by checking for response to verbal command and a absence of a lid reflex. Level of consciousness was evaluated 20 minutes later and then every 5 minutes. Postoperatively in the PACU patients were evaluated by a blinded anesthesia provider who asked about dream content and mood using a pleasantness/unpleasantness scale. The scale ranged from 1 to 5, with:

 

1 = very unpleasant

2 = quite unpleasant

3 = neither or mixed

4 = quite pleasant

5 = very pleasant

 

Patients were excluded if they did not lose consciousness with the ketamine dose, vital signs increased by 30% during the procedure as a result of anesthesia or surgery, or if they complained of an incomplete spinal block. Power analysis and statistical analysis were appropriate. A P value < 0.05 was considered significant.

 

Result A total of 125 patients were enrolled. Twenty-five were excluded for failure to lose consciousness (positive suggestion group n = 12 vs. control group n = 13). No significant differences were found in baseline demographics, STAI scores, surgical duration, or duration of sedation (P = NS). The average age was 44 years, with approximately 47% of patients in both groups being men. Sedation duration was approximately 27 minutes in both groups.

 

There was a significant association between group assignment and dream grade, with a higher frequency of patients in the positive suggestion group reporting quite pleasant or very pleasant dreams (P = 0.0097; Figure 1). No patient in the positive suggestion group reported very unpleasant dreams, as compared to 3 patients (6%) in the control group. These very unpleasant dreams were described as nightmares.

 

 

Figure 1. Grading of Dreams

Figure 1

Note. In the control group n = 12 reported no memory of the dreams vs. n = 2 in the positive suggestion group. In the control group n = 3 described very unpleasant dreams as nightmares.

 

 

In the control group 12 patients (24%) reported no memory of dreams (grade 3 = neither or mixed) as compared to 2 patients (4%) in the positive suggestion group. Of those who graded the dreams as neither or mixed (grade 3) 7 and 4 patients in the positive suggestion and control group, respectively, described their bodies as floating. Other description examples of grade 3 dreams included seeing a strange scene or color (positive suggestion group n = 4 vs. control group n = 3). Examples of quite pleasant dreams (grade 4) included “travelled” (positive suggestion group n = 3 vs. control group n = 1). In the positive suggestion group 12 patients who graded the dreams as very pleasant reported “flying” as compared to 3 in the control group. Three patients in the positive suggestion group and 2 in the control group described feeling “high as a kite.”

 

Conclusion In patients administered ketamine 0.6 mg/kg the use of a positive suggestion technique reduced the incidence of unpleasant dreams and increased patients’ evaluation of the overall mood of their dreams.

 

Comment

Ketamine is a great adjunct medication because it provides amnesia and intense analgesia. The down side is it is purported to cause recall of disturbing dreams in unpremedicated patients. Positive suggestion is a key component of hypnosis therapy. While the investigators did not evaluate hypnosis, they did evaluate the effect of positive suggestion on the recall of dreams after ketamine sedation. They reported a lower incidence of unpleasant dreams in patients told they would have “very good dreams” when they received ketamine as opposed to a control group who were told simply “you will fall asleep”. These preliminary results support the theory of positive suggestion when administering ketamine to unpremedicated patients.

 

The words and the tone of voice we use when talking with patients before and during the induction of anesthesia and sedation may influence outcomes. In fact, Varelmann et al1 reported that patients scheduled for an elective cesarean delivery reported significantly less pain with local anesthetic skin injection when they were told, “We are going to give you a local anesthetic that will numb the area and you will be comfortable during the procedure,” as opposed to “You are going to feel a big bee sting; this is the worst part of the procedure.” I frequently see students and some staff and nurses do this and I believe you are setting the patient up to expect to have a negative experience.

 

What I found interesting was that in the control group there were 12 patients (24%) who had no memory of their dreams. In the positive suggestion group 12 patients (24%) reported “flying” and rated these dreams as very pleasant. These differences may be due to the positive suggestion on dream content. The results of Varelmann et al1 support this theory.

 

There are a few limitations to this study. First, it was not clear to me if the same person administered the intervention (positive suggestion or control statement). Differences in presentation and tone of voice may influence the results. Additionally, the investigators adapted an instrument from a previous investigation. I suspect the instrument was in English, not Korean. Thus the instrument may not have been a reliable and valid instrument to use in this population.

 

A take home message I got from this study was that when possible patients should be administered midazolam prior to ketamine to minimize unpleasant dreams.

Dennis Spence, PhD, CRNA


1. Varelmann  D, Pancaro C, Cappiello EC, Camann WR. Nocebo-induced hyperalgesia during local anesthetic injection. Anesth Analg 2010;110:868-10.


The views expressed in this article are those of the author and do not reflect official policy or position of the Department of the Navy, the Department of Defense, the Uniformed Services University of the Health Sciences, or the United States Government.


© Copyright 2011 Anesthesia Abstracts · Volume 5 Number 6, June 30, 2011





Complications associated with the administration of dantrolene 1987 to 2006: a report from the North American Malignant Hyperthermia Registry of the Malignant Hyperthermia Association of the United States

Anesth Analg 2011;112:1115-23

Brandom BW, Larach MG, Chen MSA, Young MC


Abstract

Purpose The purpose of this study was to describe the complications associated with the administration of dantrolene documented on the AMRA report (adverse metabolic/musculoskeletal reaction to anesthesia) submitted to the North American Malignant Hyperthermia Society.

 

Background The only specific treatment for malignant hyperthermia (MH) is dantrolene. Dantrolene is a skeletal muscle relaxant which reduces the release of calcium from the sarcoplasmic reticulum. If MH is suspected, dantrolene should be administered as soon as possible.

 

Unfortunately, there is limited prospective data on the side effects and complications of dantrolene administration. Reported adverse effects and complications include muscle weakness, respiratory distress, pleural effusion, hepatotoxicity, phlebitis, and hyperkalemia. No large postmarketing Phase 4 studies have been published on the adverse effects of dantrolene.

 

Methodology A total of 582 AMRA reports received by the North American Malignant Hyperthermia Society between the years 1987 and 2006 were examined for inclusion in this study. Only reports that included patient weight, initial or total dantrolene dose, and treatment were included. This left 368 reports for analysis.

 

For the analysis, the clinical grading scale was used to estimate the likelihood of an MH event. The clinical grading scale is based upon clinical and laboratory data, with a score >34 indicating a likely MH event and score >49 an almost certain MH event. Two datasets were analyzed, one full dataset and one reduced dataset. The reduced dataset removed complications that may have been related to an acute MH event or underlying medical condition, rather than purely secondary to the administration of dantrolene. Two investigators with MH expertise made this determination.

 

Descriptive and inferential statistics were used to analyze the results. Results were presented as the median (range). Logistic regression was used to predict the presence or absence of complications associated with dantrolene. A P < 0.05 was significant.

 

Result In the full dataset 368 reports were included, whereas in the reduced dataset 349 reports were included. In the reduced dataset the median age was 19 years (0-78), with a weight of 66.4 kg (3-159), and a clinical grading scale score of 48 (0-88). In the reduced dataset the median total dose was 222 mg (2-6720); the total weight based dosage was 4.7 mg/kg (0.02-100), with an initial dose of 2.4 mg/kg (0-15). There was no significant difference between the subject characteristics and dantrolene doses between the full and reduced datasets (P = NS).

 

Figure 1 presents the complication frequency in the reduced dataset. In the full dataset the incidence of complications was 35.1% compared to only 23.9% in the reduced dataset. In the full dataset 3.8% of patients experienced respiratory failure and 3.3% experienced hyperkalemia. No patient in the reduced dataset experienced respiratory failure or hyperkalemia. In the full dataset 5 patients experienced pulmonary edema and 4 experienced compartment syndrome. In both datasets 5 reports described difficulty mixing dantrolene or precipitation in the IV, and 3 experienced pain on injection. Many subjects experienced more than one complication.

 

 

Figure 1. Complications Associated with Dantrolene Administration in Reduced Dataset

Figure 1

 

 

The clinical grading scale score was significantly higher in those with hyperkalemia (12 patients in the full dataset) (P = 0.005). In all cases of hyperkalemia, patients were “very likely” or “almost certain” to have experienced MH. In two cases, patients had pre-existing renal failure. Of the 14 cases with respiratory failure, 6 were due to pulmonary edema, and 2 were associated with low cardiac output. All of the patients who experienced pulmonary edema received an unknown amount of fluid administration as part of the resuscitation. In 12 of 18 cases with serious complications related to dantrolene, there was evidence of significant comorbid disease or complex surgery. In 98 cases that had additional fluids administered as part of the resuscitation, muscle weakness was 2.7 times more likely, succinylcholine was 2 times more likely to have been administered, and the total dose of dantrolene was 1.3 times larger (all P < 0.006). Additionally, patients with additional fluids administered had a median clinical grading scale score of 51 compared to a clinical grading scale of only 38 in those not administered fluids (P < 0.0005).

 

In the reduced dataset the overall complication rate was lower, most likely secondary to reduced incidence of serious comorbid disease or complex surgery. Patients in this dataset who had a pulmonary artery catheter or transesophageal echocardiography probe placed were 2.77 times less likely to experience a complication secondary to dantrolene than those without these monitors (P = 0.002). The total dose of dantrolene was significantly higher in those who experienced muscle weakness (360 mg vs. 212 mg, P = 0.011). Doubling the dantrolene dose increased the likelihood of muscle weakness by 25% (P = 0.012). Patients who received furosemide (n = 106) received a higher total dose of dantrolene (380 mg vs. 200 mg, P < 0.0005).

 

In the full dataset logistic regression modeling indicated that if the total dose of dantrolene was doubled there was a 29% increase in the risk of any complication; and a 144% increase in complications if fluids were administered during resuscitation. There was an 83% decrease in risk in the presence of neurosurgery and 74% decrease in risk in the presence of oral surgery. In contrast, in the reduced dataset the risk of any complication was increased 25% when the dose was doubled. There was a 572% increase in risk in the presence of obstetric or gynecologic surgery and a 56% decrease if furosemide was administered.

 

Conclusion Life threatening complications after dantrolene administration for suspected MH events are rare. However, complications do occur. Administration of a fluid load was associated with complications secondary to dantrolene administration in patients with significant cardiovascular, pulmonary or renal conditions, including severe MH. Use of invasive monitoring in suspected cases of MH may improve management.

 

Comment

This is an important study because it is the only published report on the complications associated with the administration of dantrolene to treat MH. Anesthesia providers should keep these complications in mind when faced with a patient with MH in whom dantrolene is administered. The most common complication is muscle weakness, which is not surprising given the mechanism of action of dantrolene. Phlebitis occurs most likely because the pH of dantrolene is very high at 9.5.

 

In patients with significant cardio-pulmonary or renal disease or complex surgery and severe cases of MH, there is an increased risk of respiratory failure, which in many cases may be secondary to pulmonary edema. Evidence of this comes from the full dataset, which included patients with significant comorbidities or complex surgery. Dantrolene has mannitol in its formulation, and this may contribute to fluid shifts, which in susceptible patients, may contribute to pulmonary edema and secondary respiratory failure. For every 1 mg of dantrolene, 3 mL of sterile water is required to reconstitute it. In this study the median total dose of dantrolene was 234 mg, which equates to 702 mL. If one considers the maximum dose administered of 6,720 mg, this would mean that the patient received over 20 liters of sterile water. If one considers additional fluids administered as part of the resuscitation, then it is not surprising that patients with significant comorbid disease would be at risk for pulmonary edema and respiratory failure.

 

The take home message from this study for me was that if providers are faced with an MH crisis, they should immediately treat with dantrolene. Providers should call for help early and consider placement of invasive monitors such as an arterial line and pulmonary artery catheter to help guide resuscitation. Newer noninvasive monitors which calculate systolic pressure variation are nice alternatives to a pulmonary artery catheter in intubated patients with normal sinus rhythm (i.e., Flo Trac sensor; see http://www.edwards.com). This is especially important in those patients with significant comorbid disease.

Dennis Spence, PhD, CRNA


Providers who would like additional information should go to the MH Association of North America website (http://mhaus.org). This website has excellent resources on MH, including a MH mock drill kit, guidelines for testing for MH susceptibility, and patient counseling guidelines.

Another resource is the North American Malignant Hyperthermia Registry (http://mhreg.org). It includes information on how to enroll patients in the MH registry, how to complete the AMRA report, as well as reports that can submitted to the registry on documenting anesthetic administered to a patient who has had a negative MH biopsy (caffeine halothane contracture test) and on the anesthetic administered to a patient with known or suspected MH.

 

The views expressed in this article are those of the author and do not reflect official policy or position of the Department of the Navy, the Department of Defense, the Uniformed Services University of the Health Sciences, or the United States Government.


© Copyright 2011 Anesthesia Abstracts · Volume 5 Number 6, June 30, 2011





A randomised comparison of intravenous remifentanil patient-controlled analgesia with epidural ropivacaine/ sufentanil during labour

Int J Obstet Anesth 2011;20:118-123

Douma MR, Middeldorp JM, Verwe RA, Dahan A, Stienstrad R


Abstract

Purpose The purpose of this study was to compare the analgesic efficacy of demand only remifentanil patient-controlled analgesia to a continuous epidural infusion of 0.1% ropivacaine with sufentanil 0.5 µg/mL at 10 mL/h in laboring parturients.

 

Background Continuous lumbar epidural analgesia (CLE) is the most common form of labor analgesia. However, this technique may be contraindicated in certain populations (i.e., coagulopathy or thrombocytopenia). Patient controlled analgesia (PCA) with remifentanil has been proposed to be a safe alternative because of its rapid onset, short 3-4 minute context sensitive half-life and 10-20 minute elimination half-life. A few previous studies have evaluated the efficacy of remifentanil in comparison to CLE, however these studies did not monitor the total duration of stage one labor analgesia.

 

Methodology This was a randomized controlled trial of 20 ASA II parturients who presented in active labor with a singleton pregnancy. Parturients were excluded if they had preeclampsia, insulin-dependent diabetes, substance abuse, remifentanil allergy, cervical dilation >5 cm, or morbid obesity (body mass index > 40 kg/m2). Parturients were randomized to either the PCA remifentanil or CLE group. The PCA remifentanil group received a loading dose of 40 µg then 40 µg every 2 minutes with a one-hour limit of 1,200 µg. The CLE group received an initial bolus of 12.5 mL of 0.2% ropivacaine followed by a continuous infusion of 0.1% ropivacaine with sufentanil 0.5 µg/mL at 10 mL/hr. Parturients could request a group assignment change at any time. If they did so within 1 hour of analgesic technique initiation, their results were excluded from the analysis. Both infusions were discontinued when parturients reached full cervical dilation. This practice was routine at hospitals in the Netherlands. Pain, satisfaction, and sedation scores were measured every hour. Pain and satisfaction scores were evaluated with a 0-10 cm visual analogue scale. Fetal heart rate tracings were monitored by blinded obstetricians. Additional data collected included the incidence of side effects and serious complications, umbilical cord blood gases, Apgar scores, and mode of delivery.

 

The primary outcome of this study was pain scores and the secondary outcomes included side effects, complications and maternal/neonatal outcomes. Statistical analysis and sample size calculations were appropriate. A P < 0.05 was considered significant.

 

Result A total of 147 parturients were screened for eligibility, 26 were enrolled, and 121 excluded. Of the 121 excluded parturients, 78 did not meet inclusion criteria and 43 declined to participate. Of the 26 parturients enrolled, 14 were randomized to the remifentanil group and 12 to CLE group. Five were excluded for delivery within one hour ( 4 remifentanil group and 1 CLE group). One was excluded for epidural catheter failure. Twenty patients completed the study.

 

No significant differences were noted between the groups. The average age of parturients was 32 with a BMI = 28.7 kg/m2. In the remifentanil group, 5 parturients were primaparous compared to 7 in the CLE group. In the remifentanil group, the mean cervical dilation was 4.2 ± 1.1 cm compared to 3.6 ± 1.3 in the CLE group. The duration of the first stage of labor was 78 minutes longer in the remifentanil group, though this difference was not statistically significant (488 ± 277 vs. 410 ± 173, P = NS). Similarly, the second stage of labor was 39 minutes longer in the remifentanil group (71 ± 40 vs. 32 ± 14, P = NS). No differences were found in the frequency of vaginal, cesarean, or instrumental delivery between the two groups. After 2 hours, 1 patient in the remifentanil group requested a labor epidural. Duration of labor analgesia was similar between the two groups (remifentanil 286 ± 145 min vs. 269 ± 142, P =NS).

 

No significant differences were found in baseline pain scores between the two groups. Pain scores in both groups were significantly lower after 1 hour, however at 2 hours the remifentanil group pain scores were back up near baseline results. The CLE group pain scores were significantly lower after 2 and 3 hours. Pain scores in the CLE group were significantly lower at all time points when compared to the remifentanil group (P < 0.05; Figure 1). Maternal SaO2 levels were similar at baseline, but were significantly lower in the remifentanil group at 1 and 3 hours, respectively (1 hour: 95.2 ± 2.4 vs. 99 ± 1.1, P < 0.01; 3 hour: 95.5 ± 3.3 vs. 99.1 ± 0.7, P < 0.05). One subject in the remifentanil group required supplemental oxygen. Maternal satisfaction scores were similar between the two groups at all time points (P = NS). Satisfaction scores were between 7.3 and 8.6 at all time points.

 

 

Figure 1. Comparison of Pain Scores

Figure 1

 

 

No significant differences were found in sedation scores between the two groups. Sedation scores were minimal in both groups. The frequency of pruritus was similar between the two groups (remifentanil 2 vs. CLE 3, P = NS). While not statistically significant, more patients in the remifentanil group experienced nausea (5 vs. 2, P = NS), and vomiting (5 vs. 1, P = NS). No significant differences were found in fetal heart rates or in umbilical cord gases or Apgar scores at 1 and 5 minutes.

 

Conclusion Continuous lumbar epidural analgesia with 0.1% ropivacaine with sufentanil 0.5 µg/mL provides more efficacious labor analgesia than demand only PCA with remifentanil. Continuous monitoring of maternal oxygenation and ventilation status is recommended given PCA with remifentanil is associated with lower pulse oximetry readings. Further research is needed to evaluate the safety of different remifentanil PCA regimens.

 

Comment

Remifentanil PCA is an attractive alternative to CLE analgesia for parturients who have contraindications to neuraxial analgesia for labor (i.e., thrombocytopenia or coagulopathy). In my experience, remifentanil can provide effective analgesia, however the technique is very labor intensive for both anesthesia and nursing staff. However, the analgesia does not approach that of CLE analgesia. At my facility, we have a standard protocol and order set for remifentanil which calls for continuous pulse oximetry and one-on-one nursing care. I think this is critical to ensuring safety of the technique.

 

In my experience, I have found some patients require a background infusion of remifentanil (0.2 µg/kg/min) and that a weight-based dose of 0.5 µg/kg is better than a fixed dose of 40 µg. However, it is important that providers consider their resources, nursing staff experience, and monitoring capabilities when considering a dosing strategy for remifentanil. As patients progress toward the second stage of labor they may need the PCA titrated up to achieve effective analgesia (i.e., pain score <4/10). Patients and nursing staff need to be educated that the analgesia is not as effective as epidural analgesia and that complete analgesia may not be achieved. A protocol should be in place that clearly defines the level of monitoring required and the plan for management of side effects and complications.

 

There are a few interesting things I want to point out from this study. First, was that 36% of parturients approached refused to participate in the study. I expect this is because many did not want to be randomized to the remifentanil group. The investigators stated they turned off the remifentanil PCA and CLE at 10 cm dilation. The rationale for discontinuing the remifentanil PCA was concern over respiratory depression in the neonate. Discontinuing the labor epidural was per hospital protocol. I assume they were concerned the CLE would slow the second stage of labor. Interestingly, the duration of the first and second stage of labor was 78 and 20 minutes shorter in the CLE group. It is important to point out that this study was underpowered to find any significant differences in any of their secondary outcomes. The investigators did point this out as the major limitation of their study.

 

In the United States, it is standard practice to continue the CLE until after delivery. I suspect in many locations in the United States PCA with remifentanil is also continued until after delivery. Turning off the PCA or CLE may result in significant pain and might decrease maternal satisfaction. The nice thing about remifentanil is that it has a very short half-life, so there are minimal effects on the neonate. A recent systematic review found PCA remifentanil had minimal effects on neonatal outcomes.1

 

Overall, I found this to be a good study. It is nice to see some randomized controlled trials on the topic. Future studies should have a large enough sample size to determine differences in side effects and complications. This would have helped increase our knowledge on the safety of PCA remifentanil in laboring parturients.

Dennis Spence, PhD, CRNA


1. Hinova A, Fernando R. Systemic remifentanil for labor analgesia. Anesth Analg 2009;109:1925-9.


The views expressed in this article are those of the author and do not reflect official policy or position of the Department of the Navy, the Department of Defense, the Uniformed Services University of the Health Sciences, or the United States Government.


© Copyright 2011 Anesthesia Abstracts · Volume 5 Number 6, June 30, 2011




Policy, Process, & Economics
The $17.1 billion problem: the annual cost of measurable medical errors

Health Aff 2011;30:596-603

Van Den Bos J, Rustagi K, Gray T, Hoalford M, Ziemkiewicz E, Shreve J


Abstract

Purpose The purpose of this study was to estimate the frequency and costs of patient injuries attributable to preventable medical errors in the United States.

 

Background Patient injuries are a safety problem and a source of unnecessary expense for the health care system. This report examined injuries to patients which resulted from preventable errors. It did not include injuries that resulted from unavoidable complications or progression of illness due to lack of care. Costs examined in this report were those directly resulting from the injury, and did not include cost of the original service or indirect costs such as those associated with malpractice premiums.

 

A previous Wisconsin study of discharge diagnostic codes demonstrated a false positive rate of 10%, in which the coded injury was not corroborated by the patient record. Discharge data can also be used to identify cases of Medicare “never events.” The Centers for Medicare and Medicaid Services (CMS) have stopped paying for hospital stays complicated by these serious errors that should never happen.

 

Methodology A nationwide data base of 24 million insured patients’ records of inpatient and outpatient care from 2000 to 2008 was the data source for this study. Discharge diagnostic codes from the Wisconsin study and Medicare “never events” were used to identify cases of patient injury. Control groups were established by matching injured patients with non-injured patients with similar encounter year, type of encounter, chronic medical conditions, age, and sex. The annual frequency of each injury was calculated from the data. Clinical and actuarial experts rated the probability that error was the cause of each identified injury. This probability was applied to the observed annual frequency of injury, resulting in the annual frequency of error resulting in injury. Each frequency of error was further reduced by 10% to account for possible false positives. The sample frequency of error resulting in injury was extrapolated to the US population using 2008 Census data. Costs were calculated as the difference between cost for control patients and patients with injuries. All costs were adjusted to reflect 2008 dollars.

 

Result The total annual cost of all the preventable errors identified was $17.1 billion. Sixty-nine percent of the total costs were related to ten types of errors. Of these ten, six were also among the ten most common errors causing injury. The frequency and costs of these six errors leading to injury are listed in table 1.

 

 

 

Table 1: Frequency and Cost of Errors Leading to Injury

 

Annual frequency

Annual cost
($ in millions)

Cost per error
($)

Postoperative infection

252,695

13,312

3,364

Pressure ulcer

374,964

8,730

3,273

Mechanical complication of noncardiac device, implant, or graft

60,380

17,709

1,069

Post-laminectomy syndrome

113,823

8,739

995

Hemorrhage complicating a procedure

78,216

8,665

678

Ventral hernia without obstruction or gangrene

53,810

6,359

342

 

 

Conclusion This study described the most frequent and most costly errors that result in patient injuries. Ten types of errors account for over two thirds of the costs. Describing errors resulting in injury is a necessary first step toward reducing their frequency and cost.

 

Comment

Patient safety is a primary goal of every anesthetic and nothing is as important to nurse anesthetists as protecting our patients from harm. Adverse outcomes such as failure to ventilate are immediately obvious. In other instances, the way we provide care can influence complications that do not become apparent until long after the anesthetic. Post operative infection is an example of the later, and was identified as the most costly injury in this study. This study provides us with a baseline measure of the most frequent and costly causes of patient injury. Information from this study can help us to focus on what health care changes are needed to help the most patients and save the most money.

 

Is it possible our anesthesia machines, monitors, or devices contribute to the rate of postoperative wound infections? Cultures of anesthesia machine surfaces have demonstrated the presence of pathologic organisms, including methacillin resistant staphylococcus aureus.1 Since it has been shown that something as simple as a stethoscope can be colonized with pathogens2, shouldn’t we think more about how we handle our phones, clipboards, notebooks, etc.? Policies prohibiting scrub suits outside the operating suite are common but are often ignored. What could we be dragging into the OR on our scrubs, and could it affect our patients? Unfortunately, patients cared for in environments with higher pathogen levels do indeed get more postoperative infections,1,3 so we can’t dismiss these ponderings as clinically irrelevant. We should be examining every element of our practice for ways to reduce postoperative infection. We should be planning our anesthetics in ways shown by scientific evidence to reduce the incidence of wound infections.

 

In recent years, our daily anesthesia routines have seen significant changes because of the Surgical Care Improvement Project (SCIP), begun in 2003 by CMS and the Centers for Disease Control and Prevention. Specifically, SCIP guidelines about antibiotic administration, temperature regulation, and serum glucose management are designed to decrease the occurrence of postoperative wound infections. Given that postoperative infections affected over a quarter of a million patients to the tune of more than $3,300 per patient during this study, no wonder the procedures mandated by the SCIP have become such a familiar routine for all of us.

 

The problem of post operative infection is so significant, we must do whatever we can to combat it. Until we get more definitive answers about what works best, we can use what we already know to reduce the risk of postoperative infections. We know that anesthetists' hands are frequently contaminated with pathogenic organisms and frequent hand washing reduces these colony counts. We know that anesthesia machines and equipment such as laryngoscopes are frequently contaminated with pathogens. Thus, it is not sufficient to clean anesthesia equipment only following "contaminated" cases; disinfection should occur following every case. We know that hypothermic patients have a higher incidence of wound infections and that keeping patients warm reduces infection rates. These fundamentals are our primary tools to insure that we protect our patients from postoperative infections.

Cassy Taylor, DNP, DMP, CRNA


1. Loftus R, Koff M, Corey B, Schwartzman J, Thorum V, Read M, Wood T, Bearch M. Transmission of pathogenic bacterial organisms in the anesthesia work area. Anesthesiology. 2008;109:399-407. (See the December 2008 issue of Anesthesia Abstracts for coverage of this article.)

2. Whittington AM, Whitlow G, Hewson D, Thomas C, Brett SJ. Bacterial contamination of stethoscopes on the intensive care unit. Anaesthesia. 2009;64:620-624. (See the May 2009 issue of Anesthesia Abstracts for coverage of the is article.)

3. Koff M, Loftus R, Buchman C, Schwartzman J, Read M, Henry E, Beach M. Reduction in intraoperative bacterial contamination of peripheral intravenous tubing through the use of a novel device. Anesthesiology 2009;110:978-85. (See the May 2009 issue of Anesthesia Abstracts for coverage of the is article.)


© Copyright 2011 Anesthesia Abstracts · Volume 5 Number 6, June 30, 2011




Regional Anesthesia
Caudal normal saline injections for the treatment of post-dural puncture headache

Pain Physician 2011;14:271-279

Abdulla S, Adbulla W, Eckhardt, R dural puncture headache, PDPH, headache, blood patch, caudal


 

Abstract

Purpose This prospective observational study was done to evaluate the effectiveness of caudal saline injections as a therapeutic approach for post dural puncture headaches (PDPH).

 

Background Post dural puncture headaches (PDPH) are one of the most common complications in anesthesia. The complication can be treated with an epidural blood patch, but this treatment does not come without risks. Complications are rare, but they include nerve root irritation, cranial nerve palsies, meningeal irritation, elevated intracranial pressure, paraparesis, cauda equina syndrome, infection, and subdural hematoma. The immediate relief of a PDPH with an epidural blood patch is thought to be from compression of the dural sac which raises cerebrospinal pressure. In theory, injection of normal saline should accomplish the same thing without many of the risks of injecting blood. A previous study comparing normal saline to blood for treatment of PDPH demonstrated a success rate of 75% for normal saline and 100% for blood.

 

Methodology During a 15 year period of time, all patients presenting with a debilitating PDPH were treated with caudal normal saline infusions at a single facility. Data was collected for patient age, height, weight, sex, dural puncture technique, difficulties encountered in performing dural puncture, clinical symptoms following saline injection, and volume of saline injected. A debilitating PDPH was defined as one that kept the patient in bed most of the day, refractory to any conservative treatment, and was not more than 3 days old. Patients were excluded that were less than 18 years old, had an elevated temperature, had coagulopathies, or had anatomical problems making caudal epidural placement a problem. The patient’s headache was recorded as follows:

  • Mild not confined to bed and no associated symptoms
  • Moderate postural headache with restricted head and neck movement – but without associated symptoms
  • Severe postural headache confining the patient to bed and associated with symptoms such as nausea, vomiting, dizziness, hearing loss, hyperacusis, tinnitus, photophobia, diplopia, stiffness of the neck, or scapular pain

 

Patients were placed in a prone position. Under sterile conditions a 20 gauge, 5 cm needle was placed in the epidural space at the sacral hiatus using loss of resistance technique. Normal saline was injected with a 20 mL syringe while the patient was asked to quantify their pain using a visual analog scale between 0 and 10 where 0 was no pain and 10 was the worst pain imaginable. A response to the pain scale was noted after 50, 80, and 100 mL of saline was infused, and at 20 minute intervals. The infusion was terminated when the patient indicated that the headache had lessened in intensity by 80-90% or became categorized as mild. The maximum amount of saline infused in one session was 220 mL.  Once the procedure was complete, the patient was asked to stand and walk. The results were then classified as complete relief, incomplete relief, or failure. Patients who had a return of severe headache, or classified as incomplete relief or failure were offered a follow up treatment within 12 hours. If the treatments continued to fail, then the patients were offered an epidural blood patch. At the end of treatment, the patients were classified as worse, moderate, good, or very good.

 

Result Out of 1,716 dural puncture procedures in a 15 year period, 60 patients developed PDPH for a 3.5% incidence. Of the 60 patients, 4 were excluded from the study. Patients were between 26 and 63 years old with 61% female and 39% male. The use of 22 gauge needles for dural puncture contributed to the majority of PDPHs; of those 4.5% developed a PDPH. The incidence of PDPH became less as the needle used became smaller, with a 27 gauge spinal needle being associated with less than a 1% rate of PDPH. Insertion of spinal catheters had a PDPH rate of 13%. Inadvertent dural puncture during epidural placement occurred at a rate of 1.2% and accounted for 7% of the total PDPHs in the study.

 

The initial caudal infusion of 50 mL of saline provided a 50% reduction in headache symptoms for half of the patients while 80 mL of saline provided a 70% reduction in headache symptoms for 91% of the patients.  Only 1 patient recovered completely after the first session. After the second session 5 patients had complete recovery. After the third session 30 patients had complete recovery, while it took four sessions for 18 patients to recover.  There were 4 failures requiring blood patches to resolve the PDPH symptoms. The mean volume of saline infused was 120 mL in the first session, 114 mL in the second session, 106 mL in third session, and 98 mL in the fourth session. The average amount of time between infusions and symptom return was 8 hours after the first infusion, 10 hours after the second infusion, and 23 hours after the third infusion.

 

Conclusion The incidence of PDPH appeared to be related to the size and design of the spinal needle, experience of the personnel performing the dural puncture, and the age and sex of the patient. The overall rate of PDPH in this study was 3.5% with the highest rate occurring when a spinal catheter was placed and the lowest rate occurring with the use of a Sprotte spinal needle. In this study, the incidence of PDPH related to patient characteristics was consistent with the literature; higher in younger adults and women.

 

The use of normal saline may provide a safer and more attractive alternative to an epidural blood patch because the saline is an inert and sterile solution. The caudal approach is relatively easy and may be beneficial in those who have had previous back surgery. Although the saline is absorbed quickly, contributing to the return of PDPH symptoms in many cases, repeated infusions appear to reduce this problem. On the average 100 mL of saline provided 85% of the patients in this study with significant reduction of symptoms. In order to maintain symptom reduction, most patients required repeated infusions 1-2 times per day over 1-2 days. The rare complication of retinal hemorrhage from epidural fluid infusion is reported in the literature, but no cases of this complication were found in this study. The epidural blood patch appears to be superior to saline infusions possibly because of its ability to occlude the puncture site which is a characteristic that saline does not possess. However, adverse symptoms from a blood patch, such as back pain, are more likely.

 

Comment

This study was done in Germany and it is not likely this could ever be done in the United States. I found it interesting that a single institution was able to use a questionable therapy for 15 years without deviating from the protocol even though it was evident that a more effective therapy was available. Regardless of how I feel about this study, it does provide some interesting information and a basis of discussion about the treatment of PDPH. Previous studies have found the infusion of saline in the epidural space to be only marginally effective for the treatment of PDPH. The theory behind treatment is that an initial increase in cerebral spinal pressure from the volume infused relieves the headache symptoms long enough for the spinal fluid to replenish itself. With adequate hydration, an individual replenishes spinal fluid about 3 times per day. A blood patch is thought to occlude the puncture site through either clotting or causing swelling of the site. Saline does not have this characteristic so it is likely that spinal fluid will continue to leak until the leak is naturally resolved in 5-7 days. This study demonstrated the likelihood of this by requiring multiple infusions over multiple days.  As a routine method of treating PDPH, saline infusion is not practical in my opinion.  As an alternative in specific cases, it should be kept in mind. Those cases might be when injecting blood would pose a significant risk of infection, when a patient refuses to have blood injected into their back but would like treatment, or when obtaining adequate amounts of blood is impossible. As indicated in the article, saline infusion is not without risks. Retinal hemorrhage is a potential complication with this technique, but also remember it is a potential complication with a blood patch as well. Treatment of PDPH should not be taken lightly. Conservative methods of fluid intake, rest, caffeine, and pain medication should always be considered first.

Steven R Wooden, DNP, CRNA


© Copyright 2011 Anesthesia Abstracts · Volume 5 Number 6, June 30, 2011




Trauma
Balanced massive transfusion ratios in multiple injury patients with traumatic brain injury

Critical Care 2011;15:R68

Peiniger S, Nienaber U, Braun M, Wafaisade A, Wutzler S, Borgmann M, Spinella PC, Maegele M


Abstract

Purpose The purpose of this study was to determine if a massive blood transfusion regimen utilizing a high fresh frozen plasma (FFP) to packed red blood cell (PRBC) ratio >1:2 would be associated with better survival rates in severely injured patients with traumatic brain injury compared to a low FFP:PRBC ratio 1:2. Survival rates were also compared in those without traumatic brain injury for high FFP:PRBC ratio >1:2 and low FFP:PRBC ratio 1:2.

 

Background The leading cause of death in severely injured trauma patients is hemorrhage, with up to 40% dying from acute exsanguination. Uncontrolled hemorrhage is associated with the lethal triad of acidosis, hypothermia, and coagulopathy. Recent retrospective analyses of severely injured patients in military and non-military settings have demonstrated improved survival with a high FFP:PRBC ratio >1:2 when massive transfusion (>10 units PRBC in 24 hours) is required. Up to 22.7% of patients with blunt traumatic brain injury present with a coagulopathy. The coagulopathy is thought to be related to tissue release of thromboplastin and low platelets. However, it is not known if a massive transfusion regimen that utilizes a high FFP:PRBC ratio improves survival in Traumatic Brain Injury patients who are severely injured.

 

Methodology This was a retrospective analysis of data from severely injured patients entered in the Trauma Registry of the Deutsche Gesellschaft für Unfallchirurgue (TR-DGU). The TR-DGU is a trauma registry which includes 166 hospitals in Germany, the majority of which are Level I trauma centers (n = 107). Inclusion criteria was a primary admission, age 16, Injury Severity Score (ISS) 16, and massive transfusion (>10 u PRBC).  Only blood products transfused between the ER and ICU admission time frame were considered. Patients were further divided based on the presence or absence of Traumatic Brain Injury and the presence or absence of a high or low FFP:PRBC ratio (greater than or less than1:2 respectively). Patients who died within the first hour of arrival to the emergency room were excluded.

 

The primary outcome was mortality rates at 6 hours, 24 hours, 30 days, and overall in-hospital mortality. Secondary outcomes included incidence of sepsis, multiorgan failure, ventilator-free days, ICU length of stay, and hospital length of stay. Multivariate logistic regression was used to predict hospital mortality from the following independent predictors: (1) transfusion ratio, (2) Revised Injury Severity Classification (RISC), and (3) need for emergency surgery. A P < 0.05 was considered significant.

 

Result A total of 1,250 severely injured patients from 2002 to 2008 were included in the analysis. There were 638 without Traumatic Brain Injury (FFP:PRBC ratio 1:2 n = 212 and FFP:PRBC ratio >1:2 n = 426) and 612 with Traumatic Brain Injury (FFP:PRBC ratio 1:2 n =167 and FFP:PRBC ratio >1:2 n = 445). The majority of the patients were male (72.3%), with a mean age of 41.8 ± 16.3 years and ISS of 41.7 ± 15.4. The predominate mechanism of injury was blunt trauma (90%). Patients with Traumatic Brain Injury had a higher overall magnitude of injury compared to those without Traumatic Brain Injury (P < 0.001). Physiologic variables such as heart rate and blood pressure were similar among all groups (heart rate approximately 100 bpm and SBP 90 mm Hg). Total crystalloids administered prior to leaving the emergency room were similar in traumatic and non-Traumatic Brain Injury patients (P = NS). Patients with a Traumatic Brain Injury who were in the FFP:PRBC ratio >1:2 group received significantly more crystalloids than the FFP:PRBC ≤1:2 group (4,000 ± 3,036 mL vs. 3,122 ± 2,640 mL, P < 0.001). In those patients with a Traumatic Brain Injury, the base deficit was significantly lower in the FFP:PRBC ≤1:2 group compared to the FFP:PRBC >1:2 group (-9.3 ± 6.5 mM/L vs. -7.3 ± 6.4 mM/L, P = 0.01). The total number of units of PRBCs were similar between the groups (P = NS). Greater than 80% of all patients had clinical and laboratory signs of coagulopathy on arrival to the emergency room.

 

Patients in the FFP:PRBC ratio >1:2 group (Traumatic Brain Injury or no Traumatic Brain Injury) had lower mortality rates across all time points (P < 0.001; Figure 1). The highest mortality rate was in patients with a Traumatic Brain Injury who received a FFP:PRBC ratio ≤1:2 regimen. The lowest mortality rate was in patients without a Traumatic Brain Injury in the FFP:PRBC ratio >1:2 regimen. Survival rates were significantly higher within each Traumatic Brain Injury subgroup in the FFP:PRBC ratio >1:2 regimen (P < 0.001). Overall, the duration of ventilation, ICU length of stay, and hospital length of stay was significantly longer in those who received a FFP:PRBC ratio >1:2 regimen (P <0.001). However, analysis of survivors data indicates that there were no significant differences in these outcomes between the high and low FFP:PRBC ratio groups (P = NS; Table 1).

 

 

Figure 1. Mortality Rate

Figure 1

 

 

 

Table 1. Secondary Outcomes

 

No Traumatic Brain Injury

Traumatic Brain Injury

 

Low 

High

P value

Low

High

P Value

Sepsis

21.5%

23.6%

0.6

15.7%

24.9%

0.04

MOF

58.5%

55.7%

0.6

67.2%

71.3%

0.4

Survivors 

Vent-free days

16.9 ± 10.2

17.4 ± 10.1

0.6

11.5 ± 9.6

11.1 ± 9.7

0.8

Survivors 

ICU LOS

24.7 ± 20.5

23.1 ± 20.6

0.3

29 ± 20.8

29.7 ± 22.3

0.7

HLOS

30.2 ± 40.3

43.3 ± 40.2

<0.001

20.6 ± 30.1

29.9 ± 36.4

<0.001

Survivors HLOS

54.3 ± 43

56.3 ± 38.5

0.4

49.2 ± 32.3

49.9 ±36.8

0.9

Note: Low = FFP:PRBC 1:2; High = FFP:PRBC >1:2; MOF = multiorgan failure; vent = ventilator; LOS = length of stay; HLOS; hospital length of stay. Results presented as % or mean ± SD.

 

 

Patients in the Traumatic Brain Injury subgroup with a high FFP:PRBC ratio regimen had a lower odds of dying when compared to those with a low FFP:PRBC ratio regimen (OR: 0.48, 95% CI: 0.29 to 0.81, P = 0.006). In the no Traumatic Brain Injury group the odds of dying was lower if a high FFP:PRBC ratio regimen was utilized, however the result was not statistically significant (OR: 0.70, 95% CI: 0.04 to 1.21, P = 0.20). In the no Traumatic Brain Injury group, the RISC score was a significant independent predictor of mortality (OR: 1.75, 95% CI: 1.52 to 2.02, P < 0.001). Need for emergency surgery was not a predictor of mortality in either Traumatic Brain Injury subgroup.

 

Conclusion Regardless of the presence or absence of a Traumatic Brain Injury, a high FFP:PRBC transfusion ratio >1:2 was associated with significantly lower mortality after acute trauma in patients requiring massive transfusion.

 

 

Comment

Damage control principles are now considered the standard of care in severely injured trauma patients in whom massive blood loss is anticipated. Damage control resuscitation has emerged as the major guiding principle for severely injured trauma patients in civilian trauma centers and military trauma facilities in Afghanistan and Iraq.1 Damage control resuscitation involves prevention and aggressive treatment of hypothermia, permissive hypotension (SBP of approximately 90 mm Hg), correction of acidosis, immediate use of FFP given in a 1:1 ratio with PRBCs, and early use of platelets (to achieve a 1:1:1 PRBC:FFP:platelet ratio). These techniques are combined with damage control surgery which seeks to rapidly control hemorrhage and prevent gastrointestinal contamination. Combined damage control resuscitation and surgery focus on minimizing iatrogenic resuscitation injury, prevention of worsening shock and coagulopathy, and control of bleeding.2 Patients are returned to the operating room within 24 to 36 hours for definitive repair after stabilization in an intensive care unit.

 

Results of this investigation support the concept of damage control resuscitation. In this study the investigators found mortality was significantly reduced in Traumatic Brain Injury and non-Traumatic Brain Injury patients in whom early and aggressive use of FFP in a FFP:PRBC ratio >1:2 was utilized. This is one of the first studies to demonstrate a beneficial effect with a balanced FFP to PRBC transfusion protocol in patients with Traumatic Brain Injury. This is important given that Traumatic Brain Injury is associated with coagulation abnormalities.

 

I would have liked to have seen the investigators present data on the ratio of platelets to FFP and PRBC. One limitation I found in the interpretation of the results was that the investigators stated that a high FFP:PRBC transfusion ratio in non-Traumatic Brain Injury patients was an independent predictor of mortality. However, the P was 0.20, which is not statistically significant and does not support this statement. Nevertheless, the mortality rate at all time points was significantly less when a high FFP:PRBC ratio regimen was utilized. I suspect with a larger sample that a high FFP:PRBC ratio would have been significant in non-Traumatic Brain Injury patients. Previous retrospective analyses of the TR-DGU database have found decreased mortality in non-Traumatic Brain Injury trauma patients when a balanced transfusion FFP : PRBC ratio regimen was utilized.3

 

Even though this was a retrospective study, the results were consistent with clinical experience of military anesthesia providers and surgeons; that a high FFP:PRBC ratio transfusion regimen is associated with improved survival.

Dennis Spence, PhD, CRNA


1. Blackborne LH. Combat damage control surgery. Crit Care Med 2008;36:S304-310.

2. Beekley AC. Damage control resuscitation: A sensible approach to the exsanguinating surgical patient. Crit Care Med 2008;36:S267–S274.

3. Maegele M, et al. Red blood cell to plasma ratios transfused during massive transfusion are associated with mortality in severe multiply injury: a retrospective analysis from the Trauma Registry of the Deutsche Gesellschaft für Unfallchirurgie. Vox Sanguinis 2008;95:112–119.


The RISC score was developed from data in the TR-DGU. It has superior precision, discriminate ability and calibration when compared to other trauma scores. It is used to calculate the probability of death based on the following 11 variables: age, ISS, head injury, severe injuries of the extremities, Glasgow Coma Scale score, PTT, base excess, cardiac arrest, and indirect signs of bleeding (SBP <90 mm Hg, hemoglobin < 9 g/dl, and massive transfusion during resuscitation).

 

The views expressed in this article are those of the author and do not reflect official policy or position of the Department of the Navy, the Department of Defense, the Uniformed Services University of the Health Sciences, or the United States Government.


© Copyright 2011 Anesthesia Abstracts · Volume 5 Number 6, June 30, 2011