Effect of Subcutaneous Unfractionated Heparin Prophylaxis on Activated Partial Thromboplastin Time: A Retrospective Evaluation.

STUDY OBJECTIVE: Characterize the incidence of elevated aPTT results in patients treated with prophylactic, subcutaneous unfractionated heparin (UFH). DESIGN: Retrospective, cohort analysis. SETTING: Single-center, university hospital. MEASUREMENTS: Evaluation of 257 patients with activated partial thromboplastin time (aPTT) testing both prior to and following subcutaneous (SC) unfractionated heparin (UFH) therapy. MAIN RESULTS: Evaluated patients received UFH 5000 units every 8 hours. Baseline aPTT values were within the normal range (mean±SD, 32.0±8.5 seconds). After initiation of UFH, aPTT values increased (mean±SD, 37.6±15.2 seconds). After 24 hours of SC UFH, mean aPTT values (mean±SD, 38.6±15.5) exceeded the normal laboratory range (23.3-35.7 seconds). An elevated aPTT result after UFH was associated with baseline aPTT, length of therapy, and weight-based UFH dose. A significant association was not identified between aPTT elevation and age, race, sex, history of liver disease, type of admission, or transfusion of blood products. CONCLUSIONS: Treatment with UFH resulted in a small, but significant, increase in aPTT.

The effect of adherence to ACLS protocols on survival of event in the setting of in-hospital cardiac arrest.

AIM: Advanced Cardiac Life Support (ACLS) algorithms are the default standard of care for in-hospital cardiac arrest (IHCA) management. However, adherence to published guidelines is relatively poor. The records of 149 patients who experienced IHCA were examined to begin to understand the association between overall adherence to ACLS protocols and successful return of spontaneous circulation (ROSC). METHODS: A retrospective chart review of medical records and code team worksheets was conducted for 75 patients who had ROSC after an IHCA event (SE group) and 74 who did not survive an IHCA event (DNS group). Protocol adherence was assessed using a detailed checklist based on the 2005 ACLS Update protocols. Several additional patient characteristics and circumstances were also examined as potential predictors of ROSC. RESULTS: In unadjusted analyses, the percentage of correct steps performed was positively correlated with ROSC from an IHCA (p<0.01), and the number of errors of commission and omission were both negatively correlated with ROSC from an IHCA (p<0.01). In multivariable models, the percentage of correct steps performed and the number of errors of commission and omission remained significantly predictive of ROSC (p<0.01 and p<0.0001, respectively) even after accounting for confounders such as the difference in age and location of the IHCAs. CONCLUSIONS: Our results show that adherence to ACLS protocols throughout an event is correlated with increased ROSC in the setting of cardiac arrest. Furthermore, the results suggest that, in addition to correct actions, both wrong actions and omissions of indicated actions lead to decreased ROSC after IHCA.

Use of an electronic decision support tool improves management of simulated in-hospital cardiac arrest.

INTRODUCTION: Adherence to advanced cardiac life support (ACLS) guidelines during in-hospital cardiac arrest (IHCA) is associated with improved outcomes, but current evidence shows that sub-optimal care is common. Successful execution of such protocols during IHCA requires rapid patient assessment and the performance of a number of ordered, time-sensitive interventions. Accordingly, we sought to determine whether the use of an electronic decision support tool (DST) improves performance during high-fidelity simulations of IHCA. METHODS: After IRB approval and written informed consent was obtained, 47 senior medical students were enrolled. All participants were ACLS certified and within one month of graduation. Each participant was issued an iPod Touch device with a DST installed that contained all ACLS management algorithms. Participants managed two scenarios of IHCA and were allowed to use the DST in one scenario and prohibited from using it in the other. All participants managed the same scenarios. Simulation sessions were video recorded and graded by trained raters according to previously validated checklists. RESULTS: Performance of correct protocol steps was significantly greater with the DST than without (84.7% v 73.8%, p<0.001) and participants committed significantly fewer additional errors when using the DST (2.5 errors vs. 3.8 errors, p<0.012). CONCLUSION: Use of an electronic DST provided a significant improvement in the management of simulated IHCA by senior medical students as measured by adherence to published guidelines.

Fast left prefrontal rTMS reduces post-gastric bypass surgery pain: findings from a large-scale, double-blind, sham-controlled clinical trial.

BACKGROUND: A single session of left prefrontal rTMS has been shown to have analgesic effects, and to reduce post-operative morphine use. We sought to test these findings in a larger sample, and try and see if multiple sessions had additive analgesic benefit. METHODS: 108 patients undergoing laparoscopic gastric bypass surgery received two sessions of 10 Hz rTMS (110% of motor threshold) over the left dorsolateral prefrontal cortex (one immediately following surgery and one 4 h later). Participants were randomly assigned to receive 2 sessions of real rTMS, 2 sessions of sham, 1 real then 1 sham, or 1 sham then 1 real rTMS treatments. Patients and study staff were blind to rTMS conditions. RESULTS: Unlike previous rTMS trials for post-operative pain, no differences emerged between groups with respect to total patient-controlled analgesia usage (IV hydromorphone). However, despite no difference in IV analgesic usage, subjects that received 2 real rTMS sessions rated both the affective and sensory dimensions of their pain significantly lower than those in the sham­sham group at several time points during the post-surgical/post-rTMS period. CONCLUSIONS: This study suggests that left prefrontal rTMS may produce significant analgesic effects in the perioperative setting. However, further work is needed to understand this effect and attempt to make it clinically useful in light of the lack of effect on PCA hydromorphone use.

Validity and reliability assessment of detailed scoring checklists for use during perioperative emergency simulation training.

INTRODUCTION: Few valid and reliable grading checklists have been published for the evaluation of performance during simulated high-stakes perioperative event management. As such, the purposes of this study were to construct valid scoring checklists for a variety of perioperative emergencies and to determine the reliability of scores produced by these checklists during continuous video review. METHODS: A group of anesthesiologists, intensivists, and educators created a set of simulation grading checklists for the assessment of the following scenarios: severe anaphylaxis, cerebrovascular accident, hyperkalemic arrest, malignant hyperthermia, and acute coronary syndrome. Checklist items were coded as critical or noncritical. Nonexpert raters evaluated 10 simulation videos in a random order, with each video being graded 4 times. A group of faculty experts also graded the videos to create a reference standard to which nonexpert ratings were compared. P < 0.05 was considered significant. RESULTS: Team leaders in the simulation videos were scored by the expert panel as having performed 56.5% of all items on the checklist (range, 43.8%-84.0%), and 67.2% of the critical items (range, 30.0%-100%). Nonexpert raters agreed with the expert assessment 89.6% of the time (95% confidence interval, 87.2%-91.6%). No learning curve development was found with repetitive video assessment or checklist use. The κ values comparing nonexpert rater assessments to the reference standard averaged 0.76 (95% confidence interval, 0.71-0.81). CONCLUSIONS: The findings indicate that the grading checklists described are valid, are reliable, and could be used in perioperative crisis management assessment.

Virtual arterial blood pressure feedback improves chest compression quality during simulated resuscitation.

INTRODUCTION: Quality chest compressions (CC) are the most important factor in successful cardiopulmonary resuscitation. Adjustment of CC based upon an invasive arterial blood pressure (ABP) display would be theoretically beneficial. Additionally, having one compressor present for longer than a 2-min cycle with an ABP display may allow for a learning process to further maximize CC. Accordingly, we tested the hypothesis that CC can be improved with a real-time display of invasively measured blood pressure and with an unchanged, physically fit compressor. METHODS: A manikin was attached to an ABP display derived from a hemodynamic model responding to parameters of CC rate, depth, and compression-decompression ratio. The area under the blood pressure curve over time (AUC) was used for data analysis. Each participant (N=20) performed 4 CPR sessions: (1) No ABP display, exchange of compressor every 2 min; (2) ABP display, exchange of compressor every 2 min; (3) no ABP display, no exchange of the compressor; (4) ABP display, no exchange of the compressor. Data were analyzed by ANOVA. Significance was set at a p-value<0.05. RESULTS: The average AUC for cycles without ABP display was 5201 mm Hgs (95% confidence interval (CI) of 4804-5597 mm Hgs), and for cycles with ABP display 6110 mm Hgs (95% CI of 5715-6507 mm Hgs) (p<0.0001). The average AUC increase with ABP display for each participant was 20.2±17.4% 95 CI (p<0.0001). CONCLUSIONS: Our study confirms the hypothesis that a real-time display of simulated ABP during CPR that responds to participant performance improves achieved and sustained ABP. However, without any real-time visual feedback, even fit compressors demonstrated degradation of CC quality.

The efficacy of automated intermittent boluses for continuous femoral nerve block: a prospective, randomized comparison to continuous infusions.

STUDY OBJECTIVE: To determine whether an automated intermittent bolus technique provides enhanced analgesia compared with a continuous infusion for femoral nerve block. DESIGN: Prospective, single-blinded, randomized controlled trial (ClinicalTrials.gov Identifier: NCT01226927). SETTING: Perioperative areas and orthopedic surgical ward of a university hospital. PATIENTS: 45 ASA physical status 1, 2, and 3 patients undergoing unilateral primary total knee arthroplasty. INTERVENTIONS: All patients received single-injection sciatic and femoral nerve blocks plus femoral nerve catheter placement for postoperative analgesia. Patients were randomly assigned to an automated intermittent bolus (5 mL every 30 min with 0.1 mL/hr basal rate) or a continuous infusion (10.1 mL/hr) delivery method of 0.2% ropivacaine. MEASUREMENTS: Consumption of intravenous patient-controlled analgesia (IV-PCA) and visual analog scale (VAS) pain scores were assessed postoperatively at set intervals until the morning of postoperative day (POD) 2. MAIN RESULTS: The mean (SEM) cumulative IV-PCA dose (mg of hydromorphone) for the 36-hour postoperative interval measured was 12.9 ± 2.32 in the continuous infusion rate group (n = 20) and 7.8 ± 1.02 in the intermittent bolus group [n = 21, t(39) = 2.04, P = 0.048; a 39 ± 14% difference in total usage]. Pain scores were statistically significantly lower in the intermittent bolus group in the afternoon of POD 1 (t(39) = 2.47, P = 0.018), but were otherwise similar. CONCLUSIONS: An automated intermittent bolus infusion technique for femoral nerve catheters is associated with clinically and statistically significantly less IV-PCA use (ie, an opioid-sparing effect) than a continuous infusion technique.

Validation of a detailed scoring checklist for use during advanced cardiac life support certification.

INTRODUCTION: Defining valid, reliable, defensible, and generalizable standards for the evaluation of learner performance is a key issue in assessing both baseline competence and mastery in medical education. However, before setting these standards of performance, the reliability of the scores yielding from a grading tool must be assessed. Accordingly, the purpose of this study was to assess the reliability of scores generated from a set of grading checklists used by nonexpert raters during simulations of American Heart Association (AHA) Megacodes. METHODS: The reliability of scores generated from a detailed set of checklists, when used by 4 nonexpert raters, was tested by grading team leader performance in 8 Megacode scenarios. Videos of the scenarios were reviewed and rated by trained faculty facilitators and a group of nonexpert raters. The videos were reviewed "continuously" and "with pauses." The grading made by 2 content experts served as the reference standard, and 4 nonexpert raters were used to test the reliability of the checklists. RESULTS: Our results demonstrate that nonexpert raters are able to produce reliable grades when using the checklists under consideration, demonstrating excellent intrarater reliability and agreement with a reference standard. The results also demonstrate that nonexpert raters can be trained in the proper use of the checklist in a short amount of time, with no discernible learning curve thereafter. Finally, our results show that a single trained rater can achieve reliable scores of team leader performance during AHA Megacodes when using our checklist in a continuous mode because measures of agreement in total scoring were very strong [Lin's (Biometrics 1989;45:255-268) concordance correlation coefficient, 0.96; intraclass correlation coefficient, 0.97]. CONCLUSIONS: We have shown that our checklists can yield reliable scores, are appropriate for use by nonexpert raters, and are able to be used during continuous assessment of team leader performance during the review of a simulated Megacode. This checklist may be more appropriate for use by advanced cardiac life support instructors during Megacode assessments than the current tools provided by the AHA.

Echocardiography in the intensive care unit.

As ultrasound technology improves and ultrasound availability increases, echocardiography utilization is growing within intensive care units. Although not replacing the often-needed comprehensive echocardiographic evaluation, limited bedside echocardiography promises to provide intensivists with enhanced diagnostic ability and improved hemodynamic understanding of individual patients. Routine and emergency echocardiography within the intensive care unit focuses on identifying and optimizing medically treatable conditions in a timely manner. Methods for such goal-directed assessments are presented.