Label Design Affects Medication Safety in an Operating Room Crisis: A Controlled Simulation Study.

OBJECTIVE: Several factors contribute to medication errors in clinical practice settings, including the design of medication labels. The objective of this study was to quantify the impact of label design on medication safety in a realistic, high-stress clinical situation. METHODS: Ninety-six anesthesia trainee participants were randomly assigned to either the redesigned or the current label condition. Participants were blinded to the study's focus on medication label design and their assigned label condition. Each participant was the sole anesthesia provider in a simulated operating room scenario involving an unexpected vascular injury. The surgeon asked the participant to administer hetastarch to the simulated patient because of hemodynamic instability. The fluid drawer of the anesthesia cart contained three 500-ml intravenous bags of hetastarch and one 500-ml intravenous bag of lidocaine. We hypothesized that redesigned labels would help participants correctly select hetastarch from the cart. If the participants incorrectly selected lidocaine from the cart, we hypothesized that the redesigned labels would help participants detect the lidocaine before administration. RESULTS: The percentage of participants who correctly selected hetastarch from the cart was significantly higher for the redesigned labels than the current labels (63% versus 40%; odds ratio, 2.61 [95% confidence interval, 1.1-6.1]; P = 0.03). Of the participants who incorrectly selected lidocaine from the cart, the percentage who detected the lidocaine before administration did not differ by label condition. CONCLUSIONS: The redesigned labels helped participants correctly select hetastarch from the cart, thus preventing some potentially catastrophic medication errors from reaching the simulated patient.

Intermediate-Acting Nondepolarizing Neuromuscular Blocking Agents and Risk of Postoperative 30-Day Morbidity and Mortality, and Long-term Survival.

BACKGROUND: Nondepolarizing neuromuscular blocking drugs (NNMBDs) are commonly used as an adjunct to general anesthesia. Residual blockade is common, but its potential adverse effects are incompletely known. This study was designed to assess the association between NNMBD use with or without neostigmine reversal and postoperative morbidity and mortality. METHODS: This is a retrospective observational study of 11,355 adult patients undergoing general anesthesia for noncardiac surgery at 5 Veterans Health Administration (VA) hospitals. Of those, 8984 received NNMBDs, and 7047 received reversal with neostigmine. The primary outcome was a composite of respiratory complications (failure to wean from the ventilator, reintubation, or pneumonia), which was "yes" if a patient had any of the 3 component events and "no" if they had none. Secondary outcomes were nonrespiratory complications, 30-day and long-term all-cause mortality. We adjusted for differences in patient risk using propensity matched (PM) followed by assessment of the association of interest by logistic regression between the matched pairs as our primary analysis and multivariable logistic regression (MLR) as a sensitivity analysis. RESULTS: Our primary aim was to assess the adverse outcomes in the patients who had received NNMBDs with and without neostigmine. Administration of an NNMBD without neostigmine reversal compared with NNMBD with neostigmine reversal was associated with increased odds of respiratory complications (PM odds ratio [OR], 1.75 [95% confidence interval [CI], 1.23-2.50]; MLR OR, 1.71 [CI, 1.24-2.37]) and a marginal increase in 30-day mortality (PM OR, 1.83 [CI, 0.99-3.37]; MLR OR, 1.78 [CI, 1.02-3.13]). However, there were no statistically significant associations with nonrespiratory complications or long-term mortality. Patients who were administered an NNMBD followed by neostigmine had no differences in outcomes compared with patients who had general anesthesia without an NNMBD. CONCLUSIONS: The use of NNMBDs without neostigmine reversal was associated with increased odds of our composite respiratory outcome compared with patients reversed with neostigmine. Based on these data, we conclude that reversal of NNMBDs should become a standard practice if extubation is planned.

Assessing student usage, perception, and the utility of a Web-based simulation in a third-year medical school clerkship.

STUDY OBJECTIVE: The goals of this study were to assess students' usage data of Web-based simulation (WBS), to determine if it can fill gaps in clinical experience-based medical education, and to determine students' perceived value of this kind of simulation during a clinical clerkship. DESIGN: Observational/prospective cohort. SETTING: Medical school affiliated with a large academic hospital. SUBJECTS: A total od 138 medical students. INTERVENTIONS: Web-based simulation. MEASUREMENTS: Medical students in an anesthesiology clerkship were assigned a WBS focusing on the clinical use of pulmonary artery catheters (PACs). Usage data, including day of week and time of day that the simulation was used and total usage time, were collected for 99 students. Eighty voluntary survey responses, which gauged student perception of the simulation and clinical exposure to PACs, were also collected. MAIN RESULTS: Seventy-two percent of attempts were made during nonclinical hours of 5 pm to 7 am. Seventy-seven percent of students spent less than 30 minutes in total using the simulation. Students preferred the simulation (rated 4.1/5) over textbook (3.59) learning to a statistically significant degree (P < .001) and held favorable views toward the simulation. Sixty-seven percent of students had never encountered a patient with a PAC before performing the simulation, and 41% did not discuss this learning objective during their clerkship. Students' self-rated understanding of PACs significantly increased from a presimulation score of 1.8 of 5, to 2.56 (mean difference, 0.760; P < .001) after using the simulation. CONCLUSIONS: WBS in medical school clerkships is accepted by students and can fill gaps in clinical medical school education, without negatively affecting students' workloads or clerkship experiences.

Association between Intraoperative Hypotension and Hypertension and 30-day Postoperative Mortality in Noncardiac Surgery.

BACKGROUND: Although deviations in intraoperative blood pressure are assumed to be associated with postoperative mortality, critical blood pressure thresholds remain undefined. Therefore, the authors estimated the intraoperative thresholds of systolic blood pressure (SBP), mean blood pressure (MAP), and diastolic blood pressure (DBP) associated with increased risk-adjusted 30-day mortality. METHODS: This retrospective cohort study combined intraoperative blood pressure data from six Veterans Affairs medical centers with 30-day outcomes to determine the risk-adjusted associations between intraoperative blood pressure and 30-day mortality. Deviations in blood pressure were assessed using three methods: (1) population thresholds (individual patient sum of area under threshold [AUT] or area over threshold 2 SDs from the mean of the population intraoperative blood pressure values), (2). absolute thresholds, and (3) percent change from baseline blood pressure. RESULTS: Thirty-day mortality was associated with (1) population threshold: systolic AUT (odds ratio, 3.3; 95% CI, 2.2 to 4.8), mean AUT (2.8; 1.9 to 4.3), and diastolic AUT (2.4; 1.6 to 3.8). Approximate conversions of AUT into its separate components of pressure and time were SBP < 67 mmHg for more than 8.2 min, MAP < 49 mmHg for more than 3.9 min, DBP < 33 mmHg for more than 4.4 min. (2) Absolute threshold: SBP < 70 mmHg for more than or equal to 5 min (odds ratio, 2.9; 95% CI, 1.7 to 4.9), MAP < 49 mmHg for more than or equal to 5 min (2.4; 1.3 to 4.6), and DBP < 30 mmHg for more than or equal to 5 min (3.2; 1.8 to 5.5). (3) Percent change: MAP decreases to more than 50% from baseline for more than or equal to 5 min (2.7; 1.5 to 5.0). Intraoperative hypertension was not associated with 30-day mortality with any of these techniques. CONCLUSION: Intraoperative hypotension, but not hypertension, is associated with increased 30-day operative mortality.

Aortic stenosis and perioperative risk with noncardiac surgery.

Aortic stenosis (AS) is characterized as a high-risk index for cardiac complications during noncardiac surgery. The American College of Cardiology/American Heart Association guidelines define severe AS as aortic valve area ≤1 cm(2), mean gradient of ≥40 mm Hg, and peak velocity of ≥4 m/s. As per current clinical practice, any of these characteristic features label a patient as at high risk for noncardiac surgery. However, these parameters appear inconsistent, particularly with respect to the aortic valve area cutoff value. The perioperative risk associated with AS during noncardiac surgery depends upon its severity (moderate vs. severe), clinical status, and the complexity of the surgical procedure (low to intermediate risk vs. high risk). A critical analysis of old and new data from published studies indicates that the significance of the presence of AS in patients undergoing noncardiac surgery is overemphasized in studies that predate the more recent advances in echocardiography and cardiac catheterization in assessment of aortic stenosis, anesthetic and surgical techniques, as well as post-operative patient care.

GlideScope Use improves intubation success rates: an observational study using propensity score matching.

BACKGROUND: Rigid video laryngoscopes are popular alternatives to direct laryngoscopy for intubation, but further large scale prospective studies comparing these devices to direct laryngoscopy in routine anesthesiology practice are needed. We hypothesized that the first pass success rate with one particular video laryngoscope, the GlideScope, would be higher than the success rate with direct laryngoscopy. METHODS: 3831 total intubation attempts were tracked in an observational study comparing first-pass success rate using a Macintosh or Miller-style laryngoscope with the GlideScope. Propensity scoring was then used to select 626 subjects matched between the two groups based on their morphologic traits. RESULTS: Comparing the GlideScope and direct laryngoscopy groups suggested that intubation would be more difficult in the GlideScope group based on the Mallampati class, cervical range of motion, mouth opening, dentition, weight, and past intubation history. Thus, a propensity score based on these factors was used to balance the groups into two 313 patient cohorts. Direct laryngoscopy was successful in 80.8% on the first-pass intubation attempt, while the GlideScope was successful in 93.6% (p <0.001; risk difference of 0.128 with a 95% CI of 0.0771 - 0.181). CONCLUSION: A greater first-attempt success rate was found when using the GlideScope versus direct laryngoscopy. In addition, the GlideScope was found to be 99% successful for intubation after initial failure of direct laryngoscopy, helping to reduce the incidence of failed intubation.

The role of diagnostic ultrasound-guided selective common peroneal nerve block in a patient with negative imaging but with classic neuropathic pain after below knee amputation.

Below-knee amputation neuromas may be hard to detect radiographically. This case report demonstrates that in a below-knee amputee with negative imaging but with classic neuropathic pain, successful diagnostic ultrasound-guided nerve-selective peripheral nerve block may be performed to diagnose the problem; subsequent resection of the neuroma may relieve severe neuropathic pain.

Endotracheal intubation skill acquisition by medical students.

BACKGROUND: During the course of their training, medical students may receive introductory experience with advanced resuscitation skills. Endotracheal intubation (ETI--the insertion of a breathing tube into the trachea) is an example of an important advanced resuscitation intervention. Only limited data characterize clinical ETI skill acquisition by medical students. We sought to characterize medical student acquisition of ETI procedural skill. METHODS: The study included third-year medical students participating in a required anesthesiology clerkship. Students performed ETI on operating room patients under the supervision of attending anesthesiologists. Students reported clinical details of each ETI effort, including patient age, sex, Mallampati score, number of direct laryngoscopies and ETI success. Using mixed-effects regression, we characterized the adjusted association between ETI success and cumulative ETI experience. RESULTS: ETI was attempted by 178 students on 1,646 patients (range 1-23 patients per student; median 9 patients per student, IQR 6-12). Overall ETI success was 75.0% (95% CI 72.9-77.1%). Adjusted for patient age, sex, Mallampati score and number of laryngoscopies, the odds of ETI success improved with cumulative ETI encounters (odds ratio 1.09 per additional ETI encounter; 95% CI 1.04-1.14). Students required at least 17 ETI encounters to achieve 90% predicted ETI success. CONCLUSIONS: In this series medical student ETI proficiency was associated with cumulative clinical procedural experience. Clinical experience may provide a viable strategy for fostering medical student procedural skills.

Eliminating arterial injury during central venous catheterization using manometry.

BACKGROUND: Unintended arterial puncture occurs in 2%-4.5% of central venous catheterizations, resulting in arterial injury in 0.1%-0.5% of patients. Routine performance of manometry during catheterization may successfully identify unintended arterial puncture and avoid arterial cannulation and injury. METHODS: We conducted a retrospective review of all cases of central venous catheter placement during a 15-yr period after implementation of a safety program requiring mandatory use of manometry to verify venous access. Arterial injuries were defined as unintended arterial cannulations with a 7-French or larger catheter or dilator. Arterial punctures were defined as the unintended placement of an 18-gauge catheter or needle into the artery. Data were reviewed for all arterial injuries during the entire 15-yr period. In addition, data on both arterial puncture and subsequent arterial injury were evaluated during the final year of analysis. RESULTS: A total of 9348 central venous catheters were placed during the observation period. During the full 15 yr of observation, there were no cases of arterial injury. During the final year of assessment, 511 central venous catheters were placed, with arterial punctures in 28 patients (5%). Arterial puncture was recognized without manometry in 24 cases. Arterial puncture was identified only with manometry in 4 cases, with no incidents of arterial injury. CONCLUSIONS: Consistent use of manometry, to verify venous placement, during central venous catheterization effectively eliminated arterial injury from unintended arterial cannulation during the 15-yr assessment.

Improving pain management communication: how patients understand the terms "opioid" and "narcotic".

BACKGROUND/OBJECTIVES: Pain specialists often advocate discontinuing use of the term "narcotic," with the negative connotations it bears for many patients, in favor of the term "opioid." To contribute empirical data to this argument, we elicited and compared patient understandings of the terms "narcotic" and "opioid." DESIGN/PARTICIPANTS: Brief, anonymous surveys were administered to 100 outpatients. Respondents were asked to describe what a narcotic/opioid is, give example(s), explain why someone would take a narcotic/opioid and describe long term consequences of use. RESULTS: Of the 100 outpatients, 86% responded "don't know" to all four opioid questions. Only 12% did not know what a narcotic was (p < 001). While 50% of patients related "narcotics" to pain management, more than a third cited addiction or abuse. Of the 100 outpatients, 78% feared an adverse outcome from long-term narcotic use, with 66% of those answers citing "addiction." CONCLUSION: Most patients were unfamiliar with the term opioid, while a substantial percentage identified a narcotic as an illegal drug and most reported adverse consequences as the outcome of long term use. Our findings, while preliminary, suggest that "opioid" is a more unfamiliar term, but raise questions about whether simply using different terminology would affect patient fears about this class of medications.