ISSN NUMBER: 1938-7172
Issue 3.10 VOLUME 3 | NUMBER 10

Editor:
Michael A. Fiedler, PhD, CRNA

Contributing Editors:
Penelope S. Benedik PhD, CRNA, RRT
Joseph F. Burkard, DNSc, CRNA
Mary A. Golinski, PhD, CRNA
Gerard T. Hogan, Jr., DNSc., CRNA
Alfred E. Lupien, PhD, CRNA
Dennis Spence, PhD, CRNA
Steven R. Wooden, MS, CRNA

Guest Editor:
Cassandra Taylor, DNP, DMP, CRNA, CNE

Assistant Editor
Jessica Floyd, BS

A Publication of Lifelong Learning, LLC © Copyright 2009

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

GENERAL
DOES SUPPLEMENTAL OXYGEN REDUCE POSTOPERATIVE NAUSEA AND VOMITING? A META-ANALYSIS OF RANDOMIZED CONTROLLED TRIALS
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  PERIOPERATIVE SAFETY IN THE LONGITUDINAL ASSESSMENT OF BARIATRIC SURGERY
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ROUTINE USE OF NASOGASTRIC TUBES DOES NOT REDUCE POSTOPERATIVE NAUSEA AND VOMITING
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REGIONAL ANESTHESIA
DOES REGIONAL ANESTHESIA IMPROVE OUTCOME AFTER TOTAL KNEE ARTHROPLASTY?
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TRAUMA
THE SUCCESS OF EMERGENCY ENDOTRACHEAL INTUBATION IN TRAUMA PATIENTS: A 10-YEAR EXPERIENCE AT A MAJOR ADULT TRAUMA REFERRAL CENTER
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PATIENT SAFETY
?WHERE ARE MY TEETH?? A CASE OF UNNOTICED INGESTION OF A DISLODGED FIXED PARTIAL DENTURE
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OBSTETRIC ANESTHESIA
EPIDEMIOLOGY OF ANESTHESIA-RELATED COMPLICATIONS IN LABOR AND DELIVERY, NEW YORK STATE, 2002-2005
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POLICY, PROCESS, & ECONOMICS
DEVELOPMENT AND PILOT EVALUATION OF A PREOPERATIVE BRIEFING PROTOCOL FOR CARDIOVASCULAR SURGERY
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General

Orhan-Sungur M, Kranke P, Sessler D, Apfel CC


 

 

Does supplemental oxygen reduce postoperative nausea and vomiting? A meta-analysis of randomized controlled trials

Anesth Analg 2008;106:1733-1738

Orhan-Sungur M, Kranke P, Sessler D, Apfel CC

 

 

Abstract

Purpose            A systematic review was performed to determine whether supplemental intraoperative oxygen is a promising clinical strategy to reduce postoperative nausea and vomiting (PONV).

Background            Studies on the use of supplemental oxygen to decrease the incidence of PONV have yielded controversial results, resulting in confusion among clinicians whether to use supplemental oxygen as a strategy to reduce the risk for PONV. The idea that supplemental oxygen may have antiemetic properties originated from studies investigating the decreased emetogenic effect of nitrous oxide in patients receiving high concentrations of oxygen instead of air. These studies questioned whether the reduction in PONV in such studies was the result of high concentrations of supplemental oxygen rather than the absence of nitrous oxide.

Methodology            A systematic search for randomized controlled trials that tested the hypothesis that prophylactic supplementation of air with high versus low oxygen concentrations during general anesthesia decreased PONV. The main outcomes were emetic events. The incidence of PONV was extracted and evaluated for three time periods: early, late, and overall period. A random effects model was used for the calculation of relative risks (RR) with supplemental oxygen versus air and the associated 95% confidence intervals.

Result            The electronic search revealed five studies that met inclusion criteria. These were included with some of the author’s work, two unpublished works and one case study for a total of 1,729 patients from 10 studies. The RR for PONV within the first 24 h after surgery in patients receiving 80% oxygen as opposed to 40% oxygen was 0.91 (95% CI 0.77-1.06). The RRs for early, late, and overall vomiting were 0.72, 0.88, and 0.82, respectively, none of which were statistically significant.

Conclusion            Initial studies postulated that oxygen might be effective at reducing PONV via prevention of subtle intestinal ischemia and hypoxia associated with abdominal surgery. Decreased blood flow is potentially important since subtle ischemia of the intestine might trigger serotonin release, which causes nausea and vomiting in at least some circumstances. These results suggest that increased intraoperative supplemental oxygen has no effect on overall PONV, regardless of type of surgery. It was also suggested that oxygen administration and subsequent high arterial oxygen tension may have a central anti-nausea effect as a result of decreased dopamine release in the carotid bodies. These findings were also not confirmed.

 

Comment

This systematic review of whether supplemental oxygen may have antiemetic properties included five studies with a total of 1,729 patients. The conclusions were that supplemental oxygen does not lead to an overall reduction in PONV and that supplemental oxygen can no longer be recommended as an effective strategy to prevent PONV.

 

Joseph F. Burkard, DNSc, CRNA

 

 

© Copyright 2009 Anesthesia Abstracts · Volume 3 Number 10, October 30, 2009





The Longitudinal Assessment of Bariatric Surgery (LABS) Consortium


Perioperative safety in the longitudinal assessment of bariatric surgery

N Engl J Med 2009;361:445-453

The Longitudinal Assessment of Bariatric Surgery (LABS) Consortium

Abstract

Purpose            The purpose of this research was to identify the incidence of, and factors associated with, 30-day safety outcomes in a cohort of patients who underwent an initial (primary) bariatric procedure.

Background            Evidence increasingly suggests the benefits of bariatric procedures may outweigh the risks. Recent studies have demonstrated the risk of death over time is approximately 35% lower among the extremely obese individuals who undergo a bariatric procedure versus those who do not have the surgery. In addition, co-morbidities such as diabetes and cardiovascular disease submit to remission following the procedure and the significant weight loss. While the actual numbers of procedures being performed has steadily increased, the safety of bariatric surgery continues to be a concern. The concerns have often been a public response to high profile reports in the media regarding untoward patient outcomes. They are often followed by threatened closure or suspension of treatment centers. Bariatric surgeons are continually being questioned by malpractice insurers regarding the increased risk incurred when providing liability coverage to the practitioners. There are some reports demonstrating higher than expected rates of deaths in high risk populations. In order to determine the incidence of adverse outcomes and factors associated with negative outcomes, a large prospective cohort who underwent primary bariatric procedures, coupled with standardized pre-surgical evaluations and completed assessments of surgical outcomes, was warranted. The Longitudinal Assessment of Bariatric Surgery (LABS) consortium conducted such a study.

Methodology            The ‘consortium’ conducted a prospective, multi-center, observational, cohort study using a standardized assessment in consecutive patients undergoing bariatric surgery. Morbidly obese patients 18 years of age or older who underwent bariatric surgery procedures by 33 different surgeons from 3/11/05 through 12/31/07 were studied. The total number of patients who had undergone the primary roux-en-Y gastric bypass (either laparoscopically or open) was 4,776. Pre-operative evaluations were completed via in person interviews, physical examinations and chart reviews. Protocols and instruments that were used to gather demographic data were standardized. Patients self-reported coexisting conditions and the severity of coexisting conditions was graded based on the use of needed healthcare resources (for example, home oxygen therapy etc). The primary outcome variable was defined as a ‘composition end- point’ of any of the following that occurred within 30 days after surgery:

  • Death
  • Deep-vein thrombosis or venous thromboembolism
  • Re-intervention with the use of percutaneous, endoscopic or operative techniques
  • Failure to be discharged within 30 days post procedure

The number of patients needed was calculated based on the ability to detect a doubling in the risk that selected outcomes events would occur. Characteristics of the patients who underwent the two procedures were compared as was the incidence of 30-day adverse outcomes. Correlations were also made between each individual surgeon.

Result            The number of patients undergoing primary bariatric procedures was 4,776. The most common procedure performed was Roux-en-Y gastric bypass (n= 3412); 87.2% of those were performed laparoscopically. A total of 1,198 patients had laparoscopic adjustable gastric banding and 166 patients had ‘other’ bariatric procedures. The median BMI was 46.5. The most common co-morbidities observed included hypertension, obstructive sleep apnea, diabetes, and asthma. Less frequently occurring and reported co-morbidities included heart disease, venous edema, deep vein thrombosis, oxygen dependence, congestive heart failure, poor functional capacity and hypertension. Regarding the primary outcome variable, 30 days post-procedure, 0.3% of patients had died:  none who had the adjustable gastric banding, 0.2% of those who had the laparoscopic Roux-en-Y, and 2.1% who had the open Roux-en-Y. The composite end point occurred within 4.1% of all patients. The following were significantly associated with the composite end point:

  • open and laparoscopic Roux-en-Y procedures as compared with the adjustable gastric banding
  •  extremes of BMI
  • inability to walk 200 ft
  • a history of deep vein thrombosis (DVT) or venous thromboembolism
  • history of obstructive sleep apnea (OSA)

Irrespective of the type of surgery performed, the predicted probability of the composite end point was lowest among those who did NOT have a history of DVT, OSA, and who were in the middle range of BMI for the cohort.

Conclusion            Despite the significant risk associated with being morbidly obese and considering the existing co-morbidities of this cohort, the overall 30-day mortality rate of 0.3% was considered low as is the rate of major adverse outcomes. Interesting to note, the characteristics of the patients (specifically male gender, co-existing medical conditions and very high BMIs), the specific surgeon, and the actual site of where the surgical procedures were performed, were previously thought to independently correlate with an increased risk of adverse outcomes. This cohort, while undergoing standardized protocols but at multiple centers, was large enough to evaluate independent factors associated with safety outcomes. In this study, only BMI and a history of venous thromboembolism were independently associated with the composite end point. The BMI demonstrated a quadratic relationship to the predictability of the composite end point. The lowest predicted risk was a BMI of 53 while a BMI of 75 showed a 61% higher risk than those with a BMI of 53.

 

Comment

It is imperative that we understand the risks that exist for those agreeing to undergo bariatric surgery. We do operationally define these surgical risks as safety outcomes related to surgical procedures, specifically these high risk procedures. Consistency exists in the literature. Morbidly obese surgical procedures make up 1-2% of our anesthesia practice! The morbidly obese patient poses a plethora of risks (again, safety outcomes) specific to the anesthesia itself. This is related to the fact that the morbidly obese typically have severe respiratory compromise including the difficult airway, cardiovascular disease in some form, and typically diabetes mellitus. These individuals are required to adhere to a medical treatment regime of pharmaceutical agents with efforts aimed at treating these severe co-morbidities. These risks, combined with surgical risks, for example, the incidence of leaking anastomosis, post- operative surgical site infections, the need for re-exploration or endoscopy procedures, when known and understood, clearly can help us determine which anesthetic technique may minimize anesthesia-related risk. Additionally, we can provide evidence based anesthesia information to our patients to facilitate their understanding and acknowledgement which may assist them with their decisions. Every patient deserves the right to know their risks; anesthesia risks are not excluded. It is typically the well informed patient that will commit to helping us help them! We would be doing a great disservice both to the patients and to the art and science of anesthesia, to NOT know the degree of risk, as much as we can, in order to maximize outcome for our patients, AND to minimize potential harm because of an ill-informed patient.

 

Mary Golinski PhD, CRNA

 

 

Adverse Outcomes within 30 days after surgery

Outcome

Total

Adj. Banding

Laparoscopic R-en-Y

Open R-en-Y

Death

15

0

6

9

DVT

20

3

12

5

Re-intubation

20

2

12

6

Endoscopy

51

1

45

5

Tracheostomy

11

0

6

5

Placement of percutaneous drain:

6

0

13

3

Abdominal re-operation:

118

9

94

15

Failure to DC

17

0

13

4

Composite EP

189

12

143

34

 

© Copyright 2009 Anesthesia Abstracts · Volume 3 Number 10, October 30, 2009





Kerger KH, Mascha E, Steinbrecher B, Frietsch T, Radke OC, Stoecklein K, Frenkel C, Fritz G, Danner K, Turan A, Apfel CC


 

Routine use of nasogastric tubes does not reduce postoperative nausea and vomiting

Anesth Analg 2009;109:768-773

Kerger KH, Mascha E, Steinbrecher B, Frietsch T, Radke OC, Stoecklein K, Frenkel C, Fritz G, Danner K, Turan A, Apfel CC

 

Abstract

Purpose            This study was done to determine whether or not routine placement of a nasogastric tube (NG) in patients undergoing general anesthesia affected the incidence of post-operative nausea and vomiting (PONV).

Background            Routine placement of NG tubes has been discussed in the literature for years.  Many anesthesia providers believe that there are advantages to the use of NG tubes to decrease the likelihood of PONV. They postulate that it removes air that is inadvertently insufflated during mask ventilation, decreases gastric volume, lowers acidity, and decompresses the stomach. Others believe that violating the esophageal sphincter and manipulation of the pharynx, esophagus, and stomach can increase the incidence of PONV.

Methodology            This was a comparative study from previously published data. The data was taken from the IMPACT trial (International Multicenter Protocol to Assess the Single and Combined Benefits of Antiemetic Strategies in a Controlled Clinical Trial of Factorial Design). In the IMPACT study, patients were randomized in a double blind fashion to many antiemetic strategies. Placement of an NG tube was not one of the strategies, but was noted in the study patients. Insertion of an NG was at the discretion of the anesthesia provider. In patients with an NG, it was placed after intubation, suctioned, then capped during the procedure. At the end of the procedure it was again suctioned, and removed under suction prior to extubation. Curiously, data involving patients who had their NG tube left in place for the 24 h postoperative data collection period were also included. Associations between PONV and NG using three outcomes (nausea, vomiting, and overall PONV) were assessed using propensity score analysis. Baseline variables that even remotely predicted NG use were taken into consideration in the calculation of propensity scores. Patients who received NG tubes were matched to patients who did not receive an NG tube using a matching algorithm that took the propensity scores into consideration. The authors then conducted a regression analysis of all multivariate models at the 0.05 level, allowing for further adjustment for any remaining potential cofounding variables. A two-tailed test of remaining data was performed. Finally, an odds ratio that looked at a 5% or greater decrease in PONV based on study variable was determined. There were no factors that showed statistical significance at an α of 0.05.

Result            A total of 4,055 patients were included in this analysis. NG tubes were not used in 2,743 patients and NG tubes were used in 1,185 patients. There was no appreciable association between perioperative NG and reduction in nausea, vomiting, or overall PONV.

Conclusion            This large multicenter study was not originally intended to look at PONV and the presence or absence of an NG tube. Data was present to allow for an analysis. Based on a logical analysis of preexisting data, there were no ties found between the use of an NG tube and PONV.

 

Comment

When I had originally read the title of this study, I had great expectations for its use in my clinical practice. After reading the study, I am not convinced by the findings. Overall, the research was sound and well conducted. Using data originally collected from another study is not new. How the data is used can vary from researcher to researcher.  I am left to wonder about a few concerns that were not addressed. Why was there no further discussion of the patients who had their NG left in during the 24 hour post operative data collection period? Was the need for an NG based solely on individual preference or was there an increased morbidity among those who the provider determined should have an NG? If I am concerned that a patient will likely go to the ICU on a ventilator postoperatively, I am much more likely to place an NG tube than if they are an outpatient going home that afternoon. I had more questions than answers after reading this study.

Gerard T. Hogan, Jr., DNSc., CRNA

 

 

© Copyright 2009 Anesthesia Abstracts · Volume 3 Number 10, October 30, 2009




Regional Anesthesia

Macfarlane A, Prasad G, Chan V, Brull R


 

 

Does regional Anesthesia Improve Outcome After Total Knee Arthroplasty?

Clin Orthop Relat Res 2009;467:2379-2402

Macfarlane A, Prasad G, Chan V, Brull R

 

 

Abstract

Purpose            The purpose of this article was to evaluate the benefits of regional anesthesia for total knee arthroplasty (TKA).

Background            A variety of regional anesthesia techniques can be used for TKA procedures.  Despite the perceived benefits of regional anesthesia for this particular procedure, some anesthesia providers continue to use general anesthesia. Some of the reasons providers avoid regional anesthesia are because of regional anesthesia failure rates, delays in anesthesia to procedure start times, and liability concerns. The benefits of regional anesthesia have been reported to include a low rate of anesthesia complications, improved post operative analgesia, reduced lengths of stay, and improved rehabilitation. Some random controlled trials comparing regional anesthesia to general anesthesia have produced conflicting results. The reason for these conflicting results may have been sample size, bias, or poor sample population selection. This article provided the results of a systematic review of literature (1990 to present) comparing regional anesthesia/analgesia to general anesthesia/analgesia for TKA.

Methodology            Several medical databases were searched for randomized controlled trials (RCTs) concerning anesthesia and analgesia for TKA. Studies that compared regional anesthesia (RA) to general anesthesia (GA) were selected and specific outcomes were identified which included mortality, cardiovascular morbidity, deep vein thrombosis (DVT), pulmonary embolus (PE), blood loss, duration of surgery, related adverse effects (nausea, vomiting, pruritus, sedation, urinary retention), cognitive defects, length of stay, and rehabilitation.

Result            There were 28 RCTs selected which compared GA versus RA for TKA. The 28 studies included 1,538 patients. There were no differences in mortality (1 study), cardiovascular morbidity (9 studies), blood loss (5 studies), and duration of surgery, between GA and RA. The benefits of regional anesthesia included a reduction in DVT (1 study), reduction in post-operative pain scores (21 studies) and reduction in opioid related side effects (18 studies). Of the 12 studies that reviewed length of stay, 2 reported a shorter length of stay with RA but the remaining studies showed no difference. Rehabilitation was improved with RA in 6 of the 14 studies that evaluated range of motion and ambulation postoperatively. Urinary retention was greater in the RA group, but other related adverse effects (nausea, vomiting, pruritus, sedation) were less in the RA group.

In examining the available evidence comparing RA to GA for TKA, several limitations were noted. Half of the 28 RCTs evaluated were determined to have used poor methodology.  Poor methodology included the lack of blinding, small samples, and the use of secondary outcomes. The lack of difference in some of the variables, such as cardiovascular morbidity, may have been the result of small sample sizes.

Conclusion            Clearly, RA had some benefits. Reduction in post operative pain, reduced opioids side effects, improved rehabilitation, and increased patient satisfaction were the most evident benefits, especially when a continuous catheter technique was used. The economic benefits associated with shorter lengths of stay should not be ignored.

Comment

Systematic review of the literature can provide a great deal of information as long as the data derived from the review is homogenous. Obtaining homogenous data is difficult because each study has its own twists, and data from one study to the next is not often compatible. That seems to be one of the biggest problems with this particular review. I got the impression that the authors had some preconceived ideas about the benefits of regional anesthesia for TKA and were disappointed when their review did not yield the expected results in certain categories.

I have been using regional anesthesia for years with TKA and would agree that there are many benefits to regional anesthesia. Being able to use morphine in a spinal anesthesia provides excellent post operative pain management. I know this because when I cannot get a spinal in a patient, pain management on the first post operative day is more difficult. I find that continuous femoral blocks with a catheter have increased patient satisfaction, reduced the need for opioids, and improved rehabilitation. My clinical impressions are consistent with what the authors of this article found. I am aware of some orthopedic physicians who do not like regional anesthesia only because they feel it delays the turnover time between surgical procedures. Accommodating the surgeon at the detriment of the patient should never be tolerated, but the issue often becomes the “elephant in the room.” There are ways to accommodate both the patient and the surgeon. Placing a block should not be a time consuming process.

Regional anesthesia for TKA is far superior to general anesthesia in my opinion. We have so many regional anesthesia options to fit any particular situation. Considerations such as issues as anticoagulation therapy are important, but femoral blocks or spinal anesthesia under most circumstances are acceptable and safe.  Epidural anesthesia is also another possibility if anticoagulation therapy precautions are considered. Both femoral block and epidural anesthesia provide for an option of continuous analgesia through catheter placement. I prefer the combination of continuous femoral nerve block for post-operative pain management with a spinal anesthetic containing morphine for intra-operative anesthesia. If the sciatic nerve becomes an issue post-operatively, I add a single shot sciatic nerve block as needed. This combination has worked well for years, and provides excellent conditions for the patient with minimal effect on surgical turnover time.

 

Steven R. Wooden, MS, CRNA

 

 

© Copyright 2009 Anesthesia Abstracts · Volume 3 Number 10, October 30, 2009




Trauma

Stephens CT, Kahntroff S, Dutton RP


 

 

The success of emergency endotracheal intubation in trauma patients: a 10-year experience at a major adult trauma referral center

Anesth Analg 2009;109:866-872

Stephens CT, Kahntroff S, Dutton RP

 

 

Abstract

Purpose            The purpose of this retrospective study was to review emergency airway management and to establish success rate and identify risk factors for difficult intubation and need for surgical airway at a Level 1 trauma center.

Background            Trauma patients present with multiple factors that contribute to difficult airway management (e.g., hemodynamic instability, facial injuries, aspiration risk). Over the last several decades there has been an increased use of difficult airway algorithms, “rescue airway devices” (LMAs), and a gradual shift towards emergency room physicians being the primary airway managers for trauma patients in the emergency room rather than anesthesia providers.

Despite a high level of success of emergency rapid sequence intubation (RSI) in trauma patients, recent studies report an incidence of surgical airways ranging from 2.6% to 3.9% by emergency room physicians and “anesthesia-trained” prehospital providers, respectively. This study reviews emergency airway management, incidence and factors associated with need for surgical airways at a Level 1 trauma center where attending anesthesiologists were responsible for the initial airway assessment and management.

Methodology            This was a retrospective review of all patients who underwent attempted intubation within 24 hours of arrival at a Trauma Center in Baltimore, MD between July 1, 1996 and June 30, 2006. Outcomes of patients requiring intubation within the first hour of arrival and within the first 24 hours were reviewed. An emergency airway management algorithm was used at the discretion of the attending anesthesiologist. After three failed attempts at direct laryngoscopy an attempt at LMA placement was made and the patient prepared for a surgical airway. Trauma anesthesia billing records, quality management records, and the Trauma Registry database where used to identify patients needing emergency airway management.

Result            Approximately 32,000 patients needed intubation within the first 24 hours of admission. Out of 6,088 patients intubated within the first hour, 6,008 were orotracheal, 59 nasal, 17 were cricothyrotomies, and 4 were tracheostomies (surgical airway rate 0.3%). Ten out of 26,000 patients intubated between 1 and 24 h of admission required surgical airways (0.04%: 4 cricothyrotomy, 6 emergent tracheotomy, and 6 tracheotomy after intubation). Of the 31 subjects requiring surgical airway management within the first 24 hours, the average age was 44.7 (range 18-86); the median Glascow Coma Scale score was 13 (range 3-15) with 26 men and 5 women. Causes of failed intubation included: foreign material in pharynx or larynx, direct injury to the head or neck with loss of upper airway anatomy and airway edema, a pharyngeal mass, larynospasm, and difficult premorbid condition; with difficult premordid condition being the most common cause for need of surgical airways. No patient died secondary to hypoxic cardiac arrest during airway management.

Conclusion            Rapid sequence intubation by experienced anesthesia providers was highly successful in trauma patients. Premorbid anatomic variation was the primary reason surgical airways were needed in this sample, although facial and neck trauma also contributed. Use of an emergency airway algorithm based on the presence of an experienced anesthesia provider, rapid sequence intubation and judicious use of selected airway adjuncts was the key to the success in this series of patients.

Comment

I thought this was a very interesting study because it is the largest reported study describing the outcomes of emergency airway management performed by anesthesia providers in a Level 1 trauma center. As the authors discussed, more and more emergency airway management, especially in trauma centers, is being performed by emergency room physicians. Unfortunately, this limits the ability of anesthesia providers and trainees to gain valuable airway management experience in trauma patients. I believe it is critical that anesthesia providers gain experience and be able to perform endotracheal intubation in trauma patients, especially for those who serve in the military.

The results of this descriptive study do provide some important points. First, it provides evidence demonstrating the need for surgical airways is rare, even in trauma patients. Second, it demonstrates, as one would expect, that patients with predictors of difficult airways (i.e, obesity, limited mouth opening, short thyromental distance, limited neck mobility, and anterior larynx) are at greater risk for failed intubation and need for surgical airway access in a trauma situation. Third, emergency airway adjuncts such as bougies and/or LMAs should be available, though in this study data on how often these devices where used could not be identified. And finally it points out how important in a trauma patient it is to have a provider available to perform a surgical airway.

As an anesthesia provider who has worked in small, rural hospitals it is nice to know that surgical airways are a rare event in trauma patients. But at the same time this study highlights the importance of being proficient with airway adjuncts and having a system and personnel (i.e., emergency room physicians, anesthesia providers, and surgeons) available to manage trauma patients. Unfortunately, this is not always feasible in small, rural hospitals. Therefore, I think it is important for anesthesia providers to be proficient with emergency airway management and airway adjuncts (i.e, bougies, intubating LMAs, glidescopes, etc.), and know who is available to perform a surgical airway in a trauma patient in the event of a failed intubation. Anesthesia providers who do not routinely manage trauma patients should consider attending difficult airway workshops periodically.

 

Dennis Spence, PhD, CRNA

 

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, Department of Defense or the United States Government.

 

© Copyright 2009 Anesthesia Abstracts · Volume 3 Number 10, October 30, 2009




Patient Safety

Lau G, Kulkarni V, Roberts GK, Brock-Utne J


 

 

”Where are my teeth?” A case of unnoticed ingestion of a dislodged fixed partial denture

Anesth Analg 2009;109:836-838

Lau G, Kulkarni V, Roberts GK, Brock-Utne J

 

 

Abstract

Purpose            The purpose of this report was to describe the outcome of a patient who swallowed a “permanent” dental bridge during or immediately following general anesthesia.

Background            Ingestion of teeth or dental appliances during general anesthesia may be unnoticed and may result in significant complications including death. Symptoms of esophageal obstruction include dysphagia, pain on swallowing, coughing, hematemesis, or vomiting. If the object reaches the stomach it has an 80% chance of passing the gut without complications. The shape and size of an ingested foreign body largely determines if it will pass through the gut. Less than 1% of ingested foreign objects result in intestinal perforation. Objects longer than 5 cm or thicker than 2 cm are likely to become trapped in the stomach. Death may be the result of sepsis, peritonitis, abscess, hemorrhage, and various other complications whether the foreign body remains in the gastrointestional tract or perforates it. While a relatively small number of individuals die each year in the USA as a result of foreign body ingestion, the incidence of foreign body ingestion during general anesthesia is unknown.

Methodology            A 36 year old man with a “permanent” dental bridge presented for surgery under general anesthesia. After induction of general anesthesia and easy mask ventilation an endotracheal tube was placed under direct vision. Anesthesia and surgery were uneventful. The patient was awakened and taken to recovery where he experienced a “bout of coughing.” The patient’s first coherent words in recovery were, “where are my teeth?” His “permanent” bridge was noted to be missing and a search of the OR and post anesthesia care unit failed to locate the missing bridge.

Result            An abdominal radiograph located the bridge in the stomach. A gastroentrologist was consulted and an immediate endoscopy was performed without locating the bridge in the stomach. A repeat radiograph showed that it had advanced into the small intestine. Subsequently, the patient experienced no abdominal pain, nausea, fever, or hematemesis. On postoperative day three the bridge was expelled rectally without complication.

Conclusion            Some patients are less able to report a missing dental appliance following surgery than was this patient. (E.g. mentally impaired, young children, severely ill.) Special care should be taken in these situations to verify that even permanent dental work remains present at the conclusion of anesthesia. When dental work is missing, prompt follow up is needed to reduce the risk of a potentially catastrophic outcome.

 

Comment

I’m sometimes amazed at how much can be learned from simple case reports such as this one. The authors did a good job of reviewing the complications of foreign body ingestion, the follow up care that is needed, and the chances that a given object will transit the gut without complication. This was a good review for me.

As anesthetists, we think and talk a lot about vigilance. This case report also serves to remind us just how important that vigilance is, even when everything goes according to plan. This patient apparently had no loose teeth, an easy airway, a routine induction and intubation, a straightforward anesthetic and surgery, an uneventful extubation, and a smooth recovery (excepting, perhaps, the “bout of coughing”). Despite all this, a string of complications occurred without detection: somehow the “permanent” anterior incisor bridge was dislodged despite easy airway management, the bridge fell into the pharynx rather than being knocked out of the mouth, the missing bridge was not noticed by the anesthetist during the case or at emergence, and, finally, the patient swallowed them rather than coughing them up or evidencing enough distress for any of his caregivers to detect the problem. Fortunately, the patient experienced no complications.

The risk of significant complications following ingestion of a foreign body appears to be fairly low in general. Much of what we do in anesthesia involves vigilant monitoring aimed at reducing the risk of very rare adverse events to their lowest achievable level. I commonly inspect my patient’s airway at the end of the case, especially if I’ve had a lot of stuff in his mouth. This makes me wonder if perhaps a more thorough inspection should become a more routine part of anesthetic care – not because I’ll find anything very often, but because it is easy to do and may prevent that one bowel perforation and peritonitis during my career that I could have caught.

 

Michael Fiedler, PhD, CRNA

 

 

© Copyright 2009 Anesthesia Abstracts · Volume 3 Number 10, October 30, 2009




Obstetric Anesthesia

Cheesman K, Brady JE, Flood P, Guohua L


 

 

Epidemiology of anesthesia-related complications in labor and delivery, new york state, 2002-2005

Anesth Analg 2009;109:1174-1181

Cheesman K, Brady JE, Flood P, Guohua L

 

 

Abstract

Purpose     The purpose of this retrospective epidemiological study was to determine the incidence and risk factors associated with anesthesia-related complications during labor and delivery in New York between 2002 and 2005 using the Healthcare Cost and Utilization Project (HCUP) New York State (NYS) Inpatient Databases (SID) files.

Background     There is limited published epidemiological data about anesthesia-related complications on labor and delivery. In the United States 1.8% of pregnancy-related deaths are associated with anesthesia-related complications. While overall maternal morbidity and mortality is extremely low, further epidemiological studies are needed to determine the incidence and risk factors associated with anesthesia related complications.

Methodology    HCUP SID files for NYS from 2002 to 2005 hospital discharges that had a diagnosis of labor and delivery were included. Anesthesia-related complications during labor and vaginal or cesarean delivery were identified by ICD-9-CM discharge diagnoses indicating: (1) systemic complications due to the administration of anesthesia in labor (e.g., pulmonary complications such as aspiration, cardiac complications, CNS complications), (2) spinal complications (e.g., reaction to spinal or epidural; headache after lumbar puncture, intraspinal abscess, spinal blood patch), (3) overdose (e.g., poisoning by spinal anesthetics), and (4) adverse effects of anesthetics and analgesics (e.g., shock due to anesthesia, MH, esophageal intubation).

Frequency distributions and 95% confidence intervals of anesthesia-related complications were presented by type and patient characteristic. Demographic and clinical characteristics included such things as age, race, method of payment, Charlson-Deyo Comorbidity Index, rural vs. urban hospital, type of admission, and method of delivery. Multivariate logistic regression was used to calculate odds ratios for risk factors of anesthesia-related complications. Sub-group analysis based on mode of delivery (vaginal vs. cesarean delivery) was conducted. Consequences of anesthesia-related mortality were evaluated by comparing length of stay and maternal in-hospital mortality rates between patients with and without complications.

Result     A total of 957,471 deliveries were included, with 8,597 recorded anesthesia-related complications out of 4,438 deliveries. Complication rates for the 8,597 events in order of prevalence were: spinal 54.7% (spinal blood patch 20.8%, intraspinal abscess 0%, reaction to spinal or lumbar puncture 33.9%), systemic 43.2% (pulmonary 2.1%, cardiac 1.9%, CNS 0.6%, other 38.3%, unspecified 0.3%) and overdose and adverse effects 2.1%. Systemic complications were more common in African American women and women 40-55 years old. Spinal complications were more common in Caucasian women and women 30-39 years old.

The overall incidence rate for women having at least one anesthesia-related complication was 0.46%. Complications were higher overall in women having cesarean delivery, over 30 years old, Caucasian women, those with private insurance, Charleson-Deyo Comorbidity Index ≥ 1,  living in rural areas, and scheduled admissions. Cesarean section accounted for 51% of all anesthesia-related complications, with complications occurring 2.1-3.2 times higher in women having cesarean delivery (adjusted odds ratio 2.51), especially in those 40-55 years of age. Odds of anesthesia related complications during cesarean section were higher with Charlson Comorbidity Index ≥ 1 (adjusted OR 1.47 vs. 1.28), and lower for rural deliveries (adjusted OR 1.33 vs. 1.65).

Anesthesia related complications were associated with about a one-day increase in length of stay when compared to no complications (3.89 ± 3.69 vs. 2.92 ± 2.38 days, P <0.0001). Overall mortality rate was 10.3 per 100,000 deliveries (96 total maternal fatalities). Of the 96 deaths, 9.4% experienced at least one anesthesia-related complication (adjusted OR for maternal mortality: 22.2, 95% confidence interval 11.20-44.24).

Conclusion     Anesthesia-related complications during labor and delivery are rare, but remain a concern, especially for women having cesarean delivery, living in rural areas, and having preexisting medical problems.

 

Comment

I believe this study demonstrated that anesthesia-related complications are extremely rare (less than 0.5%) on labor and delivery. This is one of the larger epidemiological studies done attempting to identify factors associated with anesthesia-related complications, and, on a whole, I believe it provides evidence supporting the safety of obstetric anesthesia (eg., low anesthesia-related complication rate). The magnitudes of the odd ratios reported, while statistically significant, were very low (less than 2). For example a woman having a vaginal delivery in NYS had only a 1.65 times greater risk of an anesthesia related complication than a woman living in an urban area.

Before discussing some of the findings, I do want to point out that this was a retrospective study, and as such the level of evidence is very low. The authors point out that the incidence of complications was subject to coding errors and reporting bias and that complications may be underreported. Additionally, there was a lack of information on specifics related to the anesthesia type, or specific factors associated with events, especially for those of maternal mortality. My guess is in 9.4% of maternal mortality cases with at least one anesthesia-related complication that more than one event occurred which contributed to the deaths (i.e, maternal hemorrhage during cesarean section with spinal anesthetic). The study would have been improved if the authors had done a subgroup analysis comparing complication type (systemic vs. spinal) with maternal mortality as well as providing more specifics on associated factors (i.e., rural vs. urban facilities).

As is expected, spinal blood patches accounted for almost 21% of all complications. What this tells me is that post dural puncture headaches (PDPH) are still one of the more common anesthesia-related complications. I suspect the incidence of PDPH was greater than 21%, because not all women most likely received a blood patch. The authors reported nerve root injury accounted for a large portion of the spinal complications. It is possible due to coding errors that some of these root injuries were in fact a labor complication. For example, compression of the lumbosacral trunk due to cephalo-pelvic disproportion can result in post-delivery foot-drop. This complication could be recorded as an anesthesia-related complication (spinal complication) when in fact it was a labor and delivery complication. Finally, it is reassuring to know that no intraspinal abcesses were reported.

While the odds of complications were low, women requiring a cesarean section and having more comorbidities (e.g., chronic pulmonary disease and diabetes) were at greater risk for complications. This is not surprising, and given the increasing number of cesarean deliveries and need for anesthesia in patients with significant co-existing diseases. The slightly higher rate of complications in rural facilities is not unexpected, given the limited resources (e.g., blood banks) and personnel (e.g., anesthesia providers and surgeons), especially to perform emergency cesarean deliveries. I believe the take home message is that anesthesia providers, especially in rural facilities, should be aware of what resources (i.e., blood products, airway equipment) and personnel they have available, and ensure when possible that patients with significant comorbidities are cared for at a facility capable of handling complications.

 

Dennis Spence, PhD, CRNA

 

 

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, Department of Defense or the United States Government.

© Copyright 2009 Anesthesia Abstracts · Volume 3 Number 10, October 30, 2009




Policy, Process, & Economics

Henrickson SE, Wadhera RK, ElBardissi AW, Wiegmann DA, Sundt TM


 

 

Development and pilot evaluation of a preoperative briefing protocol for cardiovascular surgery

J Am Coll Surg 2009;208:1115-1123

Henrickson SE, Wadhera RK, ElBardissi AW, Wiegmann DA, Sundt TM

 

 

Abstract

Purpose The purpose of this research was to develop and evaluate a formalized preoperative process of communication (“briefing”) among team members involved with cardiovascular surgery. Researchers were specifically interested in the effects of the briefing on patient safety and efficient use of resources.

Background            Teamwork and effective communication are essential to quality and safety in high consequence work environments, including surgery. Specific procedural routines have made a beneficial impact on teamwork in high consequence work environments outside of health care, leading to the desire to explore adoption of similar processes in the operating room. The authors proposed that patient safety would be improved by limiting surgical disruptions. Such disruptions might otherwise lead to errors, prolong surgical time, and reduce manpower available to respond to critical events.

Methodology            The preoperative briefing protocol was developed using input from fifty-six team members involved with cardiovascular surgery via a written survey and follow up discussion in a focus group format. One cardiovascular surgeon and team members from five different professional roles; surgical assistants, surgical technicians, circulating nurses, perfusionists and nurse anesthetists; were queried about their needs and views regarding the proposed briefing. Information was collected about recommended logistics of the briefing (who, when, where) along with challenges and barriers that would need to be overcome.

The briefing protocol was piloted in one operating room, during the first case of the day for one cardiovascular surgeon. Prior to implementation of the briefing, baseline data were collected during 10 pre-intervention surgical cases. Two independent observers recorded team member behaviors that resulted in disruption of the surgical work flow during the time from incision until termination of cardiopulmonary bypass. The amount of time the circulator spent making trips out of the operating room, and the number of trips, were noted. The medical record provided quantitative data relating to cost-waste reports.

The briefing was implemented for seven cases without data collection, to allow the team to practice and refine the briefing. Data were then collected from six subsequent cases.

Result            Analysis of the information obtained from the survey and focus groups established three common themes of interest: patient, procedure, and equipment. Perfusionists and nurse anesthetists rated themselves as important members of the briefing, while most other disciplines did not list either of them as important participants.

The briefing protocol was developed based on participatory communication and structured according to the identified themes. During the briefing each team member reported on their plan of care relating to the patient, procedure and equipment. The time spent in the briefing, which delayed the procedure start time, was initially eight minutes, but decreased to one minute by the end of the data collection period.

Post-intervention cases were compared to pre-intervention cases, with these statistically significant findings (student’s t-test, P <0.05):

٠      Fewer disruptive events overall (5 down from 9.5).

٠      Fewer disruptions related to procedure (2.17 down from 4.1).

٠      Fewer disruptions related to miscommunications (1.17 down from 2.5).

٠      Fewer circulator trips out of the room (4.7 down from 10).

٠      Fewer circulator minutes spent out of the room (2.2 down from 6.6).

The following differences were not statistically significant:

٠      Number of disruptions related to equipment (1.2 down from 1.9).

٠       Number of disruptions related to patient (0.5 down from 1.0)

٠      Cost-waste reports (17% down from 30%)

Conclusion            This surgical team successfully developed a preoperative briefing protocol for their cardiovascular cases. Pilot implementation of the protocol demonstrated a reduction in the number of surgical disruptions. Cost-waste savings was not demonstrated in this pilot study.

 

Comment

The aviation industry has a well developed systems approach to teamwork and safety. This successful culture is being increasingly applied to operating room environments, the most notable example being the well known “time-out.” Time outs can be applied to any invasive procedure, but have the limitation of only addressing two aspects of patient safety, surgical procedure and site. These authors propose that in order to evolve safety processes that include additional patient details, specialty specific tools will need to be developed and evaluated.

Some surgical teams may feel that their current communication processes are working well enough and hence see no need for the type of quality improvement project described in this article. In fact, many of the participants in this study expressed a similar view at the project’s outset. This article reports that the project resulted in an overall positive effect on department morale, a decrease in skepticism demonstrated by some study participants, and interest from study non-participants into adopting preoperative briefings for their cases.             The description of the development phase is fairly well detailed, and would be helpful for any department considering the development of a similar briefing process for their surgical cases.

A major contribution of the aviation approach to a culture of safety is the recognition of the vital nature of every team member’s contribution, resulting in a culture of multidisciplinary collaboration. Even in surgical teams who appear well functioning, vital contributions of some team members may remain invisible to others, in the absence of explicit processes designed to incorporate all care givers. This is illustrated by how few participants in this study initially identified perfusionists and nurse anesthetists as important to include in the briefing procedure. It is not clear from this article how, or if, participants rated the importance of anesthesiologist involvement. Anesthesiologists are not listed as participating in the survey or focus groups leading to development of the briefing protocol. Anesthesiologists were involved in the care of patients during both data collection phases and were participants in the preoperative briefings.

No data were collected pre-incision or after termination of cardiopulmonary bypass, perhaps reflective of the “surgical” perspective of the authors. As a consequence of this design, significant patient care events were not assessed (anesthesia induction, patient transfers, etc.). Future studies would benefit from including data from the entire perioperative timeframe, in order to make a stronger connection to the multidisciplinary culture of collaboration documented in the aviation industry.

Perhaps the most obvious benefit from improved communication is better access to appropriate information, enabling all team members to do their individual jobs to the best of their abilities. According to the framework of this study’s authors, this will be evidenced by fewer case disruptions. What may be even more crucial is how these briefings establish, from the very beginning of patient care, an environment in which all team members are expected to become fully engaged in the interactive communication essential for emergency response and promotion of patient safety. While emergency response was not specifically measured by these authors, this study contributes to a larger body of knowledge that makes the connection between the nature of operating room teamwork and improved patient outcomes. Anesthesia providers are important members of the team, and it is essential that they be full participants in these discussions and the standards of care that are likely to result.

 

Cassandra Taylor, DNP, DMP, CRNA, CNE

 

 

 

© Copyright 2009 Anesthesia Abstracts · Volume 3 Number 10, October 30, 2009