ISSN NUMBER: 1938-7172
Issue 6.9 VOLUME 6 | NUMBER 9

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, FAAN
Lisa Osborne, PhD, CRNA
Dennis Spence, PhD, CRNA
Cassy Taylor, DNP, DMP, CRNA
Steven R Wooden, DNP, CRNA

Assistant Editor
Jessica Floyd, BS

A Publication of Lifelong Learning, LLC © Copyright 2012

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

AIRWAY
Comparison of the Pentax-AWS airway scope with the macintosh laryngoscope for nasotracheal intubation: a randomized, prospective study
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PATIENT SAFETY
Prevention of intravenous bacterial injection from health care provider hands: the importance of catheter design and handling
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PHARMACOLOGY
The optimal dose of remifentanil for acceptable intubating conditions during propofol induction without neuromuscular blockade
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Systemic lidocaine to improve postoperative quality of recovery after ambulatory laparoscopic surgery
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Intraoperative intravenous lidocaine reduces hospital length of stay following open gastrectomy for stomach cancer in men
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POLICY, PROCESS, & ECONOMICS
Practice guidelines for central venous access
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Airway
Comparison of the Pentax-AWS airway scope with the macintosh laryngoscope for nasotracheal intubation: a randomized, prospective study

J Clin Anesth 2012;24:561-565

Suzuki A, Onodera Y, Mitamura SM, Mamiya K, Kunisawa T Takahata O, Henderson JJ, Iwasaki H


Abstract

Purpose The purpose of this study was to compare laryngeal views and ease of intubation when performing nasotracheal intubation using a Macintosh laryngoscope vs. the Pentax AWS. A secondary goal was to compare direct vs. indirect elevation of the epiglottis when using the AWS during nasotracheal intubation.

 

Background The Pentax-AWS Airway Scope is a rigid indirect videolaryngoscope. It includes in integrated video camera and screen allowing indirect visualization of the glottis and was designed primarily to facilitate oral intubation. For oral intubation, the manufacturer recommends that the disposable blade of the AWS be positioned posterior to the epiglottis to lift it directly, unlike the classic use of the Macintosh blade. There have been some anecdotal reports of the AWS being useful during nasotracheal intubations following failed attempts at oral intubation with a Macintosh laryngoscope.

 

Methodology This was a prospective, randomized study including adult ASA class I and II patients scheduled for elective oral surgery requiring nasotracheal intubation. Patients with a difficult airway, gastroesophageal reflux, or a BMI > 35 kg/m2 were excluded.Patients were randomly assigned to one of three groups immediately before induction of general anesthesia:

  1. Mac – Macintosh laryngoscope
  2. AWS Indirect – Pentax AWS with tip of blade in vallecula to lift indirectly
  3. AWS Direct – Pentax AWS with tip of blade posterior to vallecula to lift directly

All patients were induced with propofol 1.5 - 2 mg/kg and fentanyl 1 µg/kg. Vecuronium 0.1 mg/kg was used to facilitate intubation. Laryngoscopy was performed only after complete muscle relaxation. Anesthesia was maintained with 3% to 5% sevoflurane in oxygen.

 

To begin the study procedure, patients in all three groups first underwent laryngoscopy with a Macintosh blade to assess the percent of the glottis that was visible. Next, laryngoscopy was performed with the study instrument. Time for intubation was the time from the laryngoscope blade passing the teeth until the ETT was properly positioned. Ease of intubation was assessed with an established “intubation difficulty” scale, where “0” = “ideal intubating conditions” and higher numbers indicated greater difficulty with intubation. If the ETT was not placed properly within two attempts, the anesthesia provider was free to change the method of intubation according to their judgment to complete nasotracheal intubation. Statistical analysis was appropriate.

 

Result Demographic characteristics were comparable between groups. In one patient per group, intubation was not successful within two attempts. In the Mac group one intubation was completed with a Macintosh blade on the third attempt using Magill forceps. In the AWS-I group the ETT became hung up on the epiglottis. On the third intubation attempt the AWS was used lifting the epiglottis directly and the ETT placed. In the AWS-D group the ETT became hung up on the right arytenoid. On the third intubation attempt the AWS was used to lift the epiglottis indirectly and the ETT placed. The AWS disposable blade includes a guide into which the ETT is placed during oral intubation. In this last case, the nasal ETT was pushed off center when it encountered the tube guide on the disposable blade. A disposable blade without a tube guide is unavailable for the AWS.

 

When the ETT was passed through the vocal cords, the percent of glottis visible was significantly greater in the AWS-D (84%) and the AWS-I (69%) groups compared to the Mac group (50%)(P<0.01). The time to place the ETT was significantly shorter in the AWS-I group (15±5 sec) than in the AWS-D (28±12 sec, P<0.01) or Mac (26±11 sec, P<0.05) groups. Intubation Difficulty scores were highest in the Mac group (P<0.05).

 

Conclusion Using the Pentax AWS to facilitate nasotracheal intubation, and lifting the epiglottis indirectly, was associated with easier, faster intubation and a better glottic view compared to the use of a Macintosh laryngoscope. Despite the fact that the glottic view was better when the AWS was used to lift the epiglottis directly, using the AWS to lift the epiglottis indirectly like the classic Macintosh technique produced the best overall results in this study.

 

Comment

There is often something to be said for “being there” first, and I would argue that is true in the case of rigid indirect laryngoscopes. The Glidescope got there first and many of us gained experience and comfort with it early. At least partly as a result, other devices, like the McGrath Videolaryngoscope and the Pentax Airway Scope, are less used. I’ll dare say many of you reading this have never used a Pentax AWS at all. Furthermore, we tend to get pretty good with the tools we use and feel like they are the best tools, even in the absence of a careful comparison. Please don’t misunderstand, I’m not intending to be critical. I’m simply trying to point out that there may be something better than the Glidescope and it might be worth taking a look at the scientific literature and getting some hands on time before replacing old Glidescopes. I’ll also say, from a personal perspective, that I’m not trying to make a case that any one of the rigid indirect laryngoscopes is clearly superior to the others. That said, I’ve used the Pentax AWS a little bit and I’m impressed with it. I think it deserves better availability and clinical consideration than it has gotten.

 

Unfortunately, there just isn’t a good body of scientific literature comparing rigid indirect laryngoscopes yet. Most studies so far are in simulators or normal airways; most are fairly small studies. So, do they have anything to teach us? Yes, as long as our expectations aren’t too high. First, these devices may be just as useful for nasal intubation as they are oral intubation, especially if you’d prefer not to, or can’t, move the neck around much. Second, this study convinces me that using the Pentax AWS blade like a Macintosh blade is going to yield better results during nasal intubation, despite being contrary to the manufacturer’s recommendation. While problems advancing the tube into the glottis were rare in these normal airways, it certainly appears that the tube guide included on the disposable Pentax AWS blade could get in the way of the ETT. So, despite my earlier admonition that the Pentax AWS deserved more consideration when we choose an indirect videolaryngoscope, it may be that one of the other choices will be better when used for nasal intubations than the Pentax AWS.

Michael A. Fiedler, PhD, CRNA


© Copyright 2012 Anesthesia Abstracts · Volume 6 Number 9, September 30, 2012




Patient Safety
Prevention of intravenous bacterial injection from health care provider hands: the importance of catheter design and handling

Anesth Analg 2012;115:1109-19

Loftus RW, Patel HM, Huysman BC, Kispert DP, Koff MD, Gallagher JD, Jensen JT, Rowlands J, Reddy S, Dodds TM, Yeager MP, Ruoff KL, Surgenor SD, Brown JR


Abstract

Purpose The purpose of this study was to compare the bacteria injected through an Ultraport zero stopcock, with and without hub disinfection prior to use, to a conventional stopcock during routine anesthesia care. An additional purpose was to identify risk factors for intraoperative bacterial injection through an IV stopcock.

 

Background Over half a million preventable bloodstream infections per year are associated with some part of the IV set or IV catheter. Bloodstream infections originating with injection of pathogens via the IV set are associated with patient morbidity and mortality. A major factor in the development of these bloodstream infections is colonization of the lumen of the IV set with pathogens introduced through injection ports and stopcocks. Intraoperative bacterial contamination via conventional stopcocks has been associated with increased mortality at a number of medical centers. Conventional 3-way stopcocks have been shown to be contaminated with bacteria from the anesthesia provider’s hands, from patients, and the environment around the patient. The CDC does not recommend disinfection of conventional open-lumen stopcocks because these stopcocks are not considered to be disinfectable. A new class of stopcocks has been developed in an attempt to reduce the introduction of bacteria via the stopcock. These new “Disinfectable Needleless Closed Catheter” (DNCC) stopcocks incorporate a design that includes a split septum valve. They do not require a cap like a conventional stopcock. The split septum design is thought to prevent bacterial contamination of the stopcock lumen. Lab tests of these “Disinfectable Needleless Closed Catheters” have shown a decrease in bacterial entry into the IV set with their use.

 

Methodology This was a prospective, randomized, single-blind study. This study compared the Ultraport zero made by B. Braun Medical to a conventional 3-way stopcock. The Ultraport zero is a separate stopcock that incorporates the Disinfectable Needleless Closed Catheter design. The conventional stopcock was used according to CDC recommendations including closing the injection port with a sterile cap when not in use.

 

There were three groups in this study:

  1. Ultraport zero stopcock disinfected with 70% alcohol 30 seconds before injection
  2. Ultraport zero stopcock without disinfection before injection
  3. Conventional open-lumen stopcock capped between injections

These three groups were randomized across 468 OR environments. The OR environments included different combinations of anesthesia provider, patient, and operating rooms. Randomization was purposely set up to include a large number of anesthesia providers, their aseptic techniques, and different surgical procedures.

 

The stopcocks being studied were not connected to the patient, but were in the OR environment subject to similar contamination risk as the patient’s IV set. Study stopcocks were connected to a sterile collection bottle containing aerobic blood culture (BacT/Alert, Biomerieux, Durham, NC) so saline injected through the stopcock could be collected and cultured. After induction and usual post-induction care,the anesthesia provider was asked to draw up sterile saline and inject it through the study stopcock using their normal technique. This procedure was followed for a series of 5 injections. In this way, the study stopcocks were subject to the same risk of bacterial contamination during that case as was the stopcock on the patient’s IV set. Glove use and hand disinfection were not controlled before the study stopcocks were injected. During injections, the anesthesia provider’s hand decontamination, use of gloves, and syringe and needle use were observed and recorded.

 

Statistical analysis was first performed using unadjusted bacterial injection data. The analysis was repeated adjusting for risk factors that might bias the results for one of the groups, such as patient ASA physical status, number of days of prophylaxis for nasal MRSA colonization, and the anesthesia provider’s use of gloves during injection. The study was set up to achieve a power of 0.95.

 

Result All 468 OR environments were included in the analysis. For the most part, study groups were demographically comparable. In 3 of 25 demographic characteristics, there was a difference between groups. Most of these differences made it more likely that the Ultraport zero would be contaminated with bacteria.

 

None of the saline injectate samples from the Ultraport zero with disinfection were contaminated with bacteria (0/152). Bacterial contamination was found in 4% of the samples from the Ultraport zero without disinfection (7/162) and 3.2% of the conventional stopcock samples (5/154)(P=0.026). In this study, the relative risk (RR) of bacterial contamination when using the Ultraport zero with alcohol disinfection before injection was only 1.74 x 10-7 compared to the conventional open stopcock (P<0.001). These results were essentially unchanged after adjustment for a number of potentially confounding variables such as glove use by anesthesia providers.

 

Glove use was associated with a greater likelihood of bacterial contamination (RR 15, P <0.001). This was probably due to the contamination of the gloves during start of case and induction activities, since the three different stopcock groups were injected soon after induction and before a change in gloves.

 

Conclusion When disinfected with 70% alcohol before use, the Ultraport zero was associated with less bacterial contamination of injected saline solution compared to conventional open-lumen stopcocks. The chief advantage of the Ultraport zero design seems to be the ability to effectively disinfect the hub before injecting through it. The failure to change gloves after induction and before injecting drugs into the IV set during the balance of the case is likely to increase the risk of bacterial contamination of the IV set lumen no matter what sort of stopcock is used.

 

Comment

For a while now I’ve been reading studies that show the role of anesthesia in patient infections is larger than we knew and difficult to prevent. Really, it has been distressing to see how apparently common it is for anesthesia personnel to contaminate patients without any feasible plan for preventing it. After all, you can only change your gloves so many times before you’re doing more glove changing than doing the case. And equipment can be disinfected or sterilized then tucked away in a protective cover so well that you can’t perform a proper pre-case equipment check or get to it when you need it in an emergency. But, finally, this study offers us a little bit of good news … evidence of a way anesthesia can reduce patient contamination while still getting the case done.

 

The Ultraport zero is a stopcock with sort of a push button inside the lumen so that you don’t have to put a sterile cap on the open lumen after every use to keep it clean. That’s a good thing because there probably aren’t enough sterile stopcock caps in the world to put a new one on every time we make an injection during every case; and because so many providers of all types don’t do it even though we all know it is a good idea. While the design of the stopcock itself was intended to prevent bacteria from being injected through the stopcock, in this study it didn’t really do that. But what it did do was make it possible to disinfect the injection port of the stopcock with alcohol before attaching a syringe to inject a drug. That, it turns out, did prevent contamination of the stopcock and injection of bacteria. In fact, none of the injections through an Ultraport zero that had been disinfected with alcohol first contained detectable bacteria. So, now we are beginning to see some evidence of how to solve the problem.

 

I was at first confused by the finding that glove use during the injection resulted in a 14x increase in the risk of bacterial injection. If you’re like me, you think of gloves as keeping things clean, not contaminating them. While gloves may keep my hands clean, I can still move pathogens from the anesthesia machine or the patient to the IV injection site with them very easily. In this study, the test injections were made shortly after anesthesia induction and those anesthesia providers who were wearing gloves (not all did) had not changed them before making the injections. Their hands may have been clean under the gloves, but the outside of the gloves was contaminated. Glove use is important. While we can’t change gloves continually, we should think about changing them strategically. By that, I mean thinking about changing gloves, whenever possible, at specific times in the case after performing activities that are likely to contaminate them. Soon after induction is probably one of those strategic times to routinely change gloves.

 

Injection sites on the IV set are an important avenue for the introduction of pathogens into the patient’s circulation, and, ultimately bloodstream infections. While there are many factors to consider in order to prevent the IV injection of bacteria, this study gives us good evidence of one method to prevent it; using stopcocks that can be effectively disinfected before injection. My advice based upon this study is that when you use these stopcocks, ignore the manufacturer’s suggestion that the design of the stopcock itself may prevent bacterial injection and remember to disinfect the stopcock with alcohol before you inject.

Michael A. Fiedler, PhD, CRNA


© Copyright 2012 Anesthesia Abstracts · Volume 6 Number 9, September 30, 2012




Pharmacology
The optimal dose of remifentanil for acceptable intubating conditions during propofol induction without neuromuscular blockade

J Clin Anesth 2012;24:392-397

Demirkaya M, Kelsaka E, Sarihasan B, Bek Y, Üstün E


Abstract

Purpose The purpose of this study was to identify the best dose of remifentanil in combination with propofol induction to provide adequate intubating conditions without muscle relaxant.

 

Background Muscle relaxants are commonly used to facilitate endotracheal intubation. Acceptable intubating conditions can also be achieved with sufficiently deep anesthesia alone. There are reports that propofol and remifentanil provide acceptable intubating conditions without relaxant. Propofol is preferred in this combination because it provides greater inhibition of airway reflexes than pentothal or etomidate. Deepening anesthesia with propofol alone is likely to produce unacceptable hypotension in at least some patients. Opioids are known to block afferent stimulation of the airway with generally less hemodynamic effects. In doses greater than 1 µg/kg, however, remifentanil may cause stiff chest syndrome or decreased blood pressure and / or heart rate. An appropriate remifentanil dose has been studied but is not well agreed upon. In one study involving only female patients a remifentanil dose of 4µg/kg in combination with propofol was recommended.

 

Methodology This prospective, observational, double-blinded, up and down dose finding study included 50 ASA class I men between the ages of 20 and 40 years scheduled for surgery with general anesthesia. Those with reactive airway disease, a difficult airway, or a BMI less than 18.5 kg/m2 or more than 25 kg/m2 were excluded. All patients were premedicated with diazepam 10 mg 45 minutes before surgery. They were preoxygenated for three minutes. The following data were collected at baseline before induction of anesthesia, after induction, before intubation, and one minute after intubation:

  • mean arterial blood pressure
  • heart rate
  • oxygen saturation

Induction began with 2 mg/kg propofol. The first patient received remifentanil 1.0 µg/kg. In subsequent patients the remifentanil dose was increased by 0.2 µg/kg if the previous intubation was a failure and decreased by 0.2 µg/kg if the previous intubation was successful. The remifentanil was given over 30 seconds and intubation was performed 90 seconds after the remifentanil injection was complete.

 

Intubating conditions were assessed by the Viby-Mogensen system. Briefly, each intubation was subjectively graded as “excellent,” “good,” or “poor” as explained in table 1. Of note, “excellent” conditions were present if all criteria for excellent intubation conditions were present. Only one “good” criterion needed to be present for the intubation to be graded “good.” Likewise, only one “poor” criterion needed to be present for the intubation to be graded “poor.”

 

 

 

Table 1. Intubation Grading Criteria

Excellent

“easy” laryngoscopy

vocal cords abducted

no cord movement

no reaction to inserting ETT

no movement of arms or legs

Good

“fair” laryngoscopy

vocal cords “closing”

cords moving

diaphragm movement with ETT insertion

slight movement of arms or legs

Poor

“difficult” laryngoscopy

vocal cords closed

no cords moving

> 10 reaction to ETT insertion

vigorous movement of arms or legs

 

An unsuccessful intubation was defined as a patient that “reacted” or “strained” for > 10 seconds after attempted intubation. If the intubation was unsuccessful vecuronium was administered before the subsequent attempt at intubation. Statistical analysis was adequate.

 

Result The study included 50 patients in all. Their average age was 29 years old and weight 73 kg. This study predicted that the ED50 of remifentanil (effective dose in 50% of the population) as part of a successful induction and intubation without relaxant was 1.4 µg/kg. It predicted the ED95 to be 2.4 µg/kg (95% CI 1.90 to 9.0 µg/kg).

 

Heart rate and MAP decreased after remifentanil administration (P<0.001). HR and MAP increased after intubation (P<0.001). The lowest average MAP was 77 mm Hg (preintubation) and the highest average MAP 91 mm Hg (preinduction). No patient experienced hypotension that was treated, low heart rate, or skeletal muscle rigidity - commonly called stiff chest syndrome. Oxygen saturation never dropped below 98%.

 

Conclusion In combination with an induction dose of propofol, the optimal dose of remifentanil to facilitate intubation without muscle relaxants in 95% of healthy young men was 2.4 µg/kg.

 

Comment

I have long been an advocate of having a technique to intubate patients without muscle relaxant. It can be really useful in selected patients and situations. But this study does little, if anything, to convince me that their propofol / remifentanil method is the way to go. I have no confidence in the dose of remifentanil they recommended for a number of reasons. 1) they didn’t follow their own plan to increase or decrease the dose of remifentanil based upon the previous intubation for 3 of the 50 patients, 2) their dose is at odds with, and lower than, several other studies that suggest doses up to 5 µg/kg, 3) the 95% confidence interval for their 2.4 µg/kg dose was up to 9 µg/kg – over 3 times higher than the dose they recommend, 4) the recommended dose only needed to produce minimally acceptable intubation conditions – a rather low standard in my view, 5) a look at the graph of remifentanil doses used for each patient shows that the dose used never settled down into a range that was about right for most patients. This last fact, in combination with the wide confidence interval for the recommended dose, indicates to me that either they didn’t have enough patients in the study to find the right dose, or the variability in the dose is so wide that there isn’t a dose that will work for most patients. Oh, and I saved the best for last. The recommended dose was apparently extrapolated from their data, because their figure 2 shows that not one patient actually received that dose. The highest dose administered was 2 µg/kg.

 

While they didn’t see any troubling hemodynamic changes in this study despite using remifentanil doses up to 2 µg/kg, keep in mind that these were all young, healthy, fit (judging by their BMI being less than 25 kg/m2) men. I suspect many other patients would have some trouble with these doses. I’m OK with anesthesia being a little brave as long as there is a good rationale and good judgment of the risks and benefits are applied, but I’m not ready to try this technique based upon what I read in this study.

Michael A. Fiedler, PhD, CRNA


© Copyright 2012 Anesthesia Abstracts · Volume 6 Number 9, September 30, 2012





Systemic lidocaine to improve postoperative quality of recovery after ambulatory laparoscopic surgery

Anesth Analg. 2012;115:262-267

De Oliveira Jr. GS, Fitzgerald P, Streicher LF, Marcus RJ, McCarthy RJ.


Abstract

Purpose This study sought to answer the question, “Does systemically administered lidocaine reduce postoperative pain and improve the quality of recovery in outpatients?”

 

Background Postoperative pain is associated with slower postoperative recovery. Relieving pain in outpatients can be challenging even when employing multimodal analgesia. Avoiding opioids in outpatients is helpful to reduce opioid-related side effects. Systemically administered lidocaine has been shown to reduce postoperative pain. At least one study has shown that systemically administered lidocaine reduced pain in outpatients. While a sufficient dose of intraoperative opioids may result in hyperalgesia postoperatively, lidocaine has been shown to reduce remifentanil-induced hyperalgesia. The safety of relatively low dose systemic lidocaine has previously been demonstrated by research.

 

Methodology This prospective, randomized, double-blind study included healthy women undergoing outpatient gynecologic laparoscopy. Patients chronically taking opioids or who were on corticosteroids were excluded. If the laparoscopic procedure was converted to an open procedure subjects were withdrawn from the study.

 

Patients were randomized to either a lidocaine or placebo (saline) group. The lidocaine group received 1.5 mg/kg lidocaine IV followed by 2 mg/kg/h until the end of surgery. Placebo patients received the same volume of saline. All patients received 0.04 mg/kg midazolam IV preoperatively. General anesthesia was induced with 1 to 2 mg/kg propofol and maintained with sevoflurane and a remifentanil infusion. Rocuronium was used for muscle relaxation. Remifentanil was discontinued when the trocars were removed. Ketorolac 30 mg and ondansetron 4 mg were administered before emergence. In the PACU, hydromorphone 0.4 mg IV was given every five minutes until patients reported their pain as less than 4 on a 0 to 10 numeric rating scale. Being ready for discharge to home was assessed with the modified post-anesthesia discharge scoring system which evaluates vital signs, ambulation, pain, PONV, and surgical bleeding. Each category is assigned a score from 0 to 2, and higher scores are better; ≥ 9 is generally considered ready for discharge. For pain relief at home, patients were instructed to take ibuprofen 400 mg PO every 6 hours. If they needed additional pain relief they were next to take hydrocodone 10 mg/acetaminophen 325 mg.

 

Twenty-four hours later an investigator called each patient to find out how much pain medicine they had taken and to administer a Quality of Recovery questionnaire (QoR-40). The QoR-40 includes questions about physical comfort, pain, independence, psychological support, and emotional state. Scores on the QoR-40 range from 40 to 200. Higher scores represent a higher quality of recovery. The investigators accepted a 6.25% difference in QoR-40 (absolute score difference of 10) as a “clinically relevant improvement in quality of recovery.” Statistical analysis was appropriate.

 

Result A total of 63 patients completed the study and their data were analyzed, 31 in the lidocaine group and 32 in the placebo group. Demographics were no different between groups. The median difference in QoR-40 score was 16 with the lidocaine group having higher quality of recovery scores (P=0.02).

 

The lidocaine group also had less pain and used less opioid pain medicine. In the PACU, the lidocaine group used a median of 6.2 mg morphine equivalents compared to 8.6 mg morphine equivalents in the placebo group (P=0.04). From discharge home until 24 hours postop, the lidocaine group used a median of 20 mg morphine equivalents compared to 30 mg morphine equivalents in the placebo group (P=0.01). Notably, 5 patients in the lidocaine group used no opioid pain medication at home compared to only 1 patient in the placebo group. Also interesting, though perhaps not unexpected, those patients who used less opioid analgesia also reported a higher quality of recovery.

 

The average time to hospital discharge was 91 minutes in the lidocaine group compared to 118 minutes in the placebo group (P=0.03). Lidocaine patients were discharged 27 minutes earlier, on average.

 

Conclusion Patients who received a lidocaine bolus and infusion intraoperatively experienced a better quality of recovery, had less pain, and used less opioid pain medication.

 

Comment

We have known for decades that systemic lidocaine could produce a number of desirable effects in surgical patients but it is only recently that I’ve seen studies that clearly show how to use lidocaine in a clinically significant and feasible way. The doses used in this study are only slightly higher than those we used to use routinely as an antiarrhythmic in CCU patients. We have lots of evidence and clinical experience to show that such doses are generally safe in awake patients. And, of course, the CNS depression during general anesthesia makes the possibility of lidocaine CNS side effects, such as seizures, practically zero. I say all this because the idea of running an infusion of lidocaine throughout a general anesthetic sounds a bit … crazy or reckless … but upon careful consideration it is really very unlikely to cause harm at these doses. It is also pretty easy and cheap to do, so if there is a reasonable possibility that it will improve the patient’s postoperative experience we should consider doing it.

 

I’ve said it before and I’ll repeat myself here. While the QoR-40 tool has been validated and is accepted we need to remember that it is a qualitative tool. Qualitative methods can be valuable and I’m not suggesting otherwise. But we must view qualitative results differently than we view quantitative results like blood pressure and the number of milligrams of a drug used. Tools like the QoR-40 produce results that are “softer” than mm Hg or mg morphine. In my opinion, qualitative results should require larger differences to impress us because there is more “play” in their results. In this study the lidocaine group had a higher “quality of recovery,” a median QoR-40 score that was 16 points higher than the control group. While this was statistically significant, in my opinion it was, at best, only minimally clinically significant. (The investigators disagree with me. They saw it as quite significant.)

 

So am I saying that this study was no good because they used the QoR-40? Not at all. In fact, other measures showed that the intraoperative infusion of lidocaine significantly improved the patients postoperative experience. During the first 24 hours postoperatively, lidocaine patients used ⅓rd less opioid analgesia, 20 mg vs. 30 mg. That is clinically significant. Lidocaine patients were consistently discharged home about 30 minutes earlier than placebo patients despite the fact that those applying the discharge criteria had no idea which patient was in which group. That is clinically significant. My bottom line is that nothing says “I feel better” more strongly than having less pain, using less pain medicine, and meeting discharge criteria way faster. So, if you’re feeling a little bit crazy, consider adding a lidocaine bolus and infusion to the anesthetic of your outpatients and see for yourself if it makes a difference.

Michael A. Fiedler, PhD, CRNA


© Copyright 2012 Anesthesia Abstracts · Volume 6 Number 9, September 30, 2012





Intraoperative intravenous lidocaine reduces hospital length of stay following open gastrectomy for stomach cancer in men

J Clin Anesth. 2012;24:465-470

Kang JG, Kim MH, Kim EH, Lee SH


Abstract

Purpose The purpose of this study was to examine the effects of a systemic bolus and infusion of lidocaine during general anesthesia on pain, postoperative opioid analgesia consumption, ileus, and time until readiness for discharge in men having subtotal gastrectomy.

 

Background Pain intensity, analgesic medication use, and recovery of bowel function are key aspects of recovery after intraabdominal surgery. Opioid side effects include PONV, respiratory depression, pruritus, and ileus. Interventions that reduce the need for opioid analgesia speed the return of bowel function and readiness for discharge. Lidocaine has analgesic, antihyperalgesic and anti-inflammatory effects. Intraoperative systemic lidocaine has been shown to improve postoperative recovery; specifically to reduce pain, reduce need for opioid analgesia, reduce inflammation, speed the return of bowel function, and speed readiness for discharge. In other studies, patients who received a lidocaine infusion had better pain relief following open prostatectomy and laparoscopic colectomy.

 

Methodology This was a prospective, randomized, double-blind study of ASA class I and II men, 45 years to 60 years old, having subtotal gastrectomy. Exclusion criteria included severe system disease and preoperative analgesic maintenance therapy.

 

Patients were randomized into a lidocaine or placebo group. the lidocaine group received an IV bolus of 1.5 mg/kg before skin incision followed by an infusion of 1.5 mg/kg/h until skin closure. Placebo patients received an equal volume of saline. All patients were induced with sodium pentothal and maintained with sevoflurane in 50% oxygen and air. Vecuronium was used for muscle relaxation. No opioids were administered until just prior to emergence. Fifteen minutes before the end of surgery all patients received 0.5 mg/kg Demerol. In the PACU, IVPCA with fentanyl and ketorolac was begun. The basal rate included 15 µg/h fentanyl and 1.8 mg/h ketorolac. A demand dose and lockout was also provided. In addition to the IVPCA, patients could receive supplemental Demerol and a fentanyl patch upon request. Patients were assessed for lidocaine side effects throughout the perioperative period. Pain at rest was assessed with a visual analogue scale from 0 to 10 at 24, 48, and 72 hours postoperatively. The time to first flatus and defecation were recorded. Hospital discharge occurred when patients met specific discharge criteria, as judged by surgeons blinded to their group assignment. Statistical analysis was appropriate.

 

Result A total of 47 patients were included in the analysis; 24 lidocaine patients and 23 placebo patients. Patient demographics were similar. Hemodynamic changes that might be attributed to lidocaine, such as severe hypotension; low heart rate; or arrhythmias, did not occur intraoperatively. Likewise, no patients reported circumoral numbness, a metallic taste, or visual disturbances while in the PACU.

 

The amount of Demerol administered in the PACU and IVPCA use at 24 hours, 48 hours, and 72 hours was no different between groups. The number of patients who requested additional pain medicine above the IVPCA and visual analogue scale pain intensities were no different between groups. However, the median total dose of Demerol per patient who asked for additional pain medication was significantly less in the lidocaine group, 50 mg, than in the placebo group, 150 mg (P=0.04). Fentanyl patches were used in 1 lidocaine patient vs. 3 placebo patients and the IVPCA was refilled in 1 lidocaine patient vs. 2 placebo patients, though these differences were not statistically significant. The time to return of bowel function was not statistically significantly different between groups. The time to first defecation was 10 hours earlier in the lidocaine group. Nevertheless, the lidocaine group had a significantly shorter length of hospital stay. Lidocaine patients were discharged in an average of 8.7±1 days vs. 9.5±3 days for placebo patients (P=0.006). 

 

Conclusion A low dose bolus and infusion of lidocaine significantly decreased postoperative opioids needed for pain relief following subtotal gastrectomy. Length of stay postoperatively was also reduced by 0.8 days.

 

Comment

Lest you were tempted to think the last study of lidocaine administration in laparoscopic surgery patients was a fluke, I’ve included this second study, showing very similar results, to press my point. Don’t give in to the temptation to think that lidocaine didn’t make much difference in these inpatients having a substantial surgery because pain scores, Demerol given in the PACU, and IVPCA use weren’t any different between groups. Remember, open gastrectomies are fairly big cases and quite painful. What lidocaine did in this case was substantially reduce the amount of pain medication needed postoperatively. Lidocaine patients used a full two thirds less Demerol above and beyond their IVPCA, on average, than placebo patients. They were also less likely to need a fentanyl patch or an IVPCA refill. But the final proof that lidocaine was beneficial to gastrectomy patients was the fact that they met hospital discharge criteria almost a day sooner than placebo patients. Not only does this show that the patients were doing better, but it also significantly reduces the cost of care for this surgical population. For inpatient surgery, postoperative care has been shown to make up 50% or more of variable costs. So every day a patient does not spend in the hospital represents a big savings.

 

In some ways the previous study of outpatients makes a stronger case for administering systemic lidocaine than this study does. Because outpatient surgeries are generally less painful than open procedures requiring inpatient postoperative care, the lidocaine took a bigger bite out of pain in the outpatient study than in this one. Similarly, because being ready for discharge within hours after surgery is paramount in outpatients, the percentage reduction in time until readiness for discharge was actually much larger in the outpatient study than in this one. I suspect there are few alternate ways to achieve those results in the outpatients, while, in this study, systemic lidocaine is probably one of several ways to achieve the reduction in opioid requirement and faster discharge. Any way you look at it, however, these results are impressive. We should give this technique serious consideration.

Michael A. Fiedler, PhD, CRNA


© Copyright 2012 Anesthesia Abstracts · Volume 6 Number 9, September 30, 2012




Policy, Process, & Economics
Practice guidelines for central venous access

Anesthesiology 2012;116:539-573

American Society of Anesthesiologists Task Force on Central Venous Access, Rupp SM, Apfelbaum JL, Blitt C, Caplan RA, Connis RT, Domino KB, Fleisher LA, Grant S, Mark JB, Morray JP, Nickinovich DG, Tung A


Abstract

Purpose The purpose of this article was to present systematically developed recommendations for central venous catheterization.

 

Background Central venous access practice guidelines provide information about placement and management that may improve patient safety and decrease the risk of adverse outcomes.

 

Methodology These practice guidelines were formulated by a Task Force of the American Society of Anesthesiologists (ASA). The Task Force evaluated the literature to identify findings related to central line placement as well as the strength of the evidence presented. Meta-analysis of multiple trials was considered stronger evidence than single randomized controlled trials. Findings were considered supportive if statistically significant differences were reported. If the research was observational in nature the level of evidence was considered only suggestive. Areas for which no clear pattern emerged were classified as mixed results. For some areas of concern, the available evidence was insufficient to draw a conclusion. Surveys were conducted to describe the opinions of identified experts and society members. Open forums were held to obtain comments regarding clinical feasibility of the proposed recommendations.

 

Result Recommendations focused on prevention of infection and mechanical injuries such as arterial puncture, thromboemboli, or hematoma. Recommendations related to infection prevention based on strong literature support were administration of antibiotics to immunocompromised patients, use of infection resistant catheters in high risk patients, and use of upper body insertion sites. Additional recommendations based on suggestive studies were using a checklist during insertion, avoiding contaminated or potentially contaminated sites, and removing catheters when no longer needed. Additional recommendations were made based on conflicting literature results or opinions. All of the recommendations relating to infection risk are listed in Table 1.

 

 

Table 1 Recommendations to Reduce Risk of Infection

Recommendation

Level of evidence

Antibiotic prophylaxis for immunocompromised patients

Supportive

Catheter coated with antibiotics or a combination of chlorhexidine and silver sulfadiazine for high infection risk patients

Supportive

Upper body insertion site

Supportive

Insertion performed using a checklist

Suggestive

Avoid contaminated or potentially contaminated insertion sites

Suggestive 

Remove catheters when no longer needed

Suggestive 

Insertion under maximal barriers (sterile gowns/gloves, caps, masks, full body drape)

Mixed

Skin antisepsis using chlorhexidine with alcohol

Mixed

Transparent bio-occlusive dressing with chlorhexidine

Mixed

Replace catheter when infection suspected, rather than at specific time intervals

Mixed

Catheter replacement to new insertion site, rather than over guidewire to existing site

Mixed

Needleless catheter access ports

Mixed

Cap unused access ports

Insufficient/Opinion

Aseptic wipe to access ports

Insufficient/Opinion

Insertion performed in controlled environment

Insufficient/Opinion

Insertion performed using standardized equipment

Insufficient/Opinion

Insertion performed using an assistant

Insufficient/Opinion

Catheter fixation with sutures, staples, or tape

Insufficient

 

Supported recommendations related to mechanical injuries included use of upper body site and confirmation of placement using continuous electrocardiography. The use of ultrasound before or during cannulation of the internal jugular, subclavian, or femoral veins was found to have literature support. Additional recommendations based on suggestive studies were Trendelenburg positioning for insertion, use of small gauge catheters, methods to verify venous placement, and surgical removal of arterially placed catheters. Additional recommendations were made based on conflicting literature results or opinions. All of the recommendations relating to mechanical injuries are listed in Table 2.

 

 

Table 2 Recommendations to Reduce Risk of Mechanical Injuries

Recommendation

Level of evidence

Upper body insertion site

Supportive

Static ultrasound pre-prep for internal jugular insertion

Supportive

Real time ultrasound for internal jugular insertion

Supportive

Real time ultrasound for subclavian insertion

Supportive

Real time ultrasound for femoral insertion

Supportive

Post operatively or when clinically appropriate, verify catheter tip position using continuous electrocardiography

Supportive

Internal jugular or subclavian insertion performed in Trendelenburg

Suggestive

Use smallest appropriate catheter size

Suggestive

During thin-wall-needle Seldinger technique insertion, verify venous placement of wire using ultrasound, or transesophageal echocardiography

Suggestive

During insertion, verify venous placement of catheter or thin-wall-needle using manometry

Suggestive

Before catheter use, verify venous placement using manometry

Suggestive

Post operatively or when clinically appropriate, verify catheter tip position using chest radiography or fluoroscopy

Suggestive

Consult surgeon or interventional radiologist for removal of unintended arterial placement of large bore dilator or catheter

Suggestive

Static ultrasound pre-prep subclavian insertion

Mixed

Static ultrasound pre-prep femoral insertion

Insufficient/Opinion

During insertion, verify venous placement of catheter or thin-wall-needle by ultrasound, pressure waveform analysis, or venous blood gas

Mixed

During thin-wall-needle Seldinger technique insertion, verify venous placement of wire using continuous electrocardiography or fluoroscopy

Insufficient/Opinion

Before catheter use, verify venous placement using pressure waveform

Insufficient/Opinion

Use of thin-wall-needle Seldinger or catheter-over-the-needle modified Seldinger technique

Insufficient

Maximum number of insertion attempts based on clinical judgment

Insufficient

 

Conclusion The above information describes the strength of evidence supporting many aspects of central line placement. This evidence may be used to formulate functional guidelines for central line placement.

 

Comment

This information provides us with a foundation upon which to make evidence based decisions regarding insertion and management of central venous catheters. It is important to remember that these studies are limited to elective catheter insertions. They do not address peripherally inserted central catheters, pulmonary artery catheters, or tunneled central lines such as permacaths or portacaths. Although the original article does contain information regarding pediatric patients, only the recommendations related to adults are summarized here.

 

This information relates to practice guidelines; meaning that scientific review supports some of these management practices, but the evidence is not strong enough to make them practice standards. While practice standards are generally accepted principles that should be followed under most circumstances, guidelines may be modified or rejected as determined by individual clinical need. As we apply a guideline to an individual situation, it is prudent to take its level of evidentiary support into account. Recommendations based on opinion do not carry the weight of those supported by properly conducted research studies. Consequently, it is more likely that a decision to perform a catheter insertion using a non-standardized equipment tray would be more reasonable than failing to give prophylactic antibiotics to an immunocompromised patient.

 

This includes new information pertinent to guidance of catheter placement. Point of care ultrasound is a relatively new technology, but it is quickly becoming widely available. This review demonstrates that the usefulness of ultrasound during central venous catheterization is supported by the literature, and may merit adoption as a best practice.

 

Even the best supported evidence presented here does not constitute a standard to be adopted verbatim. Instead, it provides us with up-to-date information that we can use in the evaluation and revision of our departmental policies and in our clinical practice decisions. When making those decisions, we should incorporate both research findings and patient specific information.

Cassy Taylor, DNP, DMP, CRNA


© Copyright 2012 Anesthesia Abstracts · Volume 6 Number 9, September 30, 2012