Roman Dudaryk

Three-Dimensional Transesophageal Echocardiography for Perioperative Right Ventricular Assessment

BACKGROUND In high-risk cardiac procedures, dynamic analysis of right ventricular (RV) performance is desirable, but the geometric complexity of the RV limits the applicability of current two-dimensional echocardiographic imaging techniques. This study aimed to evaluate the utility of three-dimensional transesophageal echocardiography (TEE) for the perioperative assessment of RV function and dimensions. METHODS Patients undergoing cardiac surgical procedures with complete TEE examinations were identified and reviewed according to current guidelines to exclude patients with significant coexisting valvular regurgitation. Full-volume, three-dimensional datasets were analyzed by two independent investigators using stand-alone software, and left ventricular and RV dimensions were recorded. RESULTS Datasets from 50 patients undergoing cardiac surgical procedures were evaluated for this study. The mean RV volume was 111.7 mL (range, 37.5 to 349.7 mL) at end diastole and 67.6 mL (range, 25.5 to 274.4 mL) at end systole. Intraobserver reliability was 0.93 and 0.90 for end diastolic and 0.77 and 0.87 for end systolic volumes. The interobserver reliability for RV volumes was 0.83 at end diastole and 0.86 at end systole. The mean stroke volume was 43.6 mL (range, 12 to 111.2 mL) for the RV and 49.1 mL (range, 19.9 to 102.8 mL) for the left ventricle; the correlation coefficient between the two was 0.85. CONCLUSIONS Three-dimensional TEE volumetric measurements were reproducible across a wide range of RV dimensions. As postulated by the continuity principle, stroke volume measurements between both ventricles correlated well, supporting the validity of this approach. Therefore, our work provides preliminary evidence that three-dimensional TEE offers reproducible information about RV function and size in the dynamic and complex perioperative setting of cardiac surgical procedures.

What is new in the blood bank for trauma resuscitation

Purpose of review The aim of the present review was to describe recent changes in blood banking thinking, practice, and products that affect trauma care. Recent findings Prompt balanced hemostatic resuscitation of major hemorrhage from trauma improves outcome and reduces blood use. New blood processes and products can help deliver appropriate doses of procoagulant plasma and platelets quicker and more safely. New processes include holding larger inventories of thawed plasma with risk of wastage and rapid plasma thawers. New products in the blood bank include group A or group A low-titer B thawed plasma and AB or A liquid (never-frozen) plasma for resuscitation, prepooled cultured whole blood–derived platelets in plasma, and prepooled cryoprecipitate in varying pool sizes. Single-donor apheresis or pooled whole blood–derived platelets in additive solution, designed to reduce plasma-related transfusion reactions, are also increasingly available but are not an appropriate blood component for hemorrhage control resuscitation because they reduce the total amount of administered plasma coagulation factors by 10%. Summary Early initiation of balanced massive transfusion protocols leading to hemostatic resuscitation is lifesaving. Changing blood product availability and composition will lead to higher complexity of massive transfusion. It is critical that anesthesiologists understand the composition of the available new blood products to use them correctly. Video abstract http://links.lww.com/COAN/A38

Intraoperative noise increases perceived task load and fatigue in anesthesiology residents: A simulation-based study

BACKGROUND:Operating rooms are identified as being one of the noisiest of clinical environments, and intraoperative noise is associated with adverse effects on staff and patient safety. Simulation-based experiments would offer controllable and safe venues for investigating this noise problem. However, realistic simulation of the clinical auditory environment is rare in current simulators. Therefore, we retrofitted our operating room simulator to be able to produce immersive auditory simulations with the use of typical sound sources encountered during surgeries. Then, we tested the hypothesis that anesthesia residents would perceive greater task load and fatigue while giving simulated lunch breaks in noisy environments rather than in quiet ones. As a secondary objective, we proposed and tested the plausibility of a novel psychometric instrument for the assessment of stress. METHODS:In this simulation-based, randomized, repeated-measures, crossover study, 2 validated psychometric survey instruments, the NASA Task Load Index (NASA-TLX), composed of 6 items, and the Swedish Occupational Fatigue Inventory (SOFI), composed of 5 items, were used to assess perceived task load and fatigue, respectively, in first-year anesthesia residents. Residents completed the psychometric instruments after giving lunch breaks in quiet and noisy intraoperative environments (soundscapes). The effects of soundscape grouping on the psychometric instruments and their comprising items were analyzed with a split-plot analysis. A model for a new psychometric instrument for measuring stress that combines the NASA-TLX and SOFI instruments was proposed, and a factor analysis was performed on the collected data to determine the model’s plausibility. RESULTS:Twenty residents participated in this study. Multivariate analysis of variance showed an effect of soundscape grouping on the combined NASA-TLX and SOFI instrument items (P = 0.003) and the comparisons of univariate item reached significance for the NASA Temporal Demand item (P = 0.0004) and the SOFI Lack of Energy item (P = 0.001). Factor analysis extracted 4 factors, which were assigned the following construct names for model development: Psychological Task Load, Psychological Fatigue, Acute Physical Load, and Performance-Chronic Physical Load. Six of the 7 fit tests used in the partial confirmatory factor analysis were positive when we fitted the data to the proposed model, suggesting that further validation is warranted. CONCLUSIONS:This study provides evidence that noise during surgery can increase feelings of stress, as measured by perceived task load and fatigue levels, in anesthesiologists and adds to the growing literature pointing to an overall adverse impact of clinical noise on caregivers and patient safety. The psychometric model proposed in this study for assessing perceived stress is plausible based on factor analysis and will be useful for characterizing the impact of the clinical environment on subject stress levels in future investigations.

Simulating environmental and psychological acoustic factors of the operating room.

In this study, an operating room simulation environment was adapted to include quadraphonic speakers, which were used to recreate a composed clinical soundscape. To assess validity of the composed soundscape, several acoustic parameters of this simulated environment were acquired in the presence of alarms only, background noise only, or both. These parameters were also measured for comparison from size-matched operating rooms at Jackson Memorial Hospital. The parameters examined included sound level, reverberation time, and predictive metrics of speech intelligibility in quiet and noise. It was found that the sound levels and acoustic parameters were comparable between the simulated environment and the actual operating rooms. The impact of the background noise on the perception of medical alarms was then examined, and was found to have little impact on the audibility of the alarms. This study is a first in kind report of a comparison between the environmental and psychological acoustical parameters of a hospital simulation environment and actual operating rooms.

Fluid Resuscitation for Trauma Patients: Crystalloids Versus Colloids

Controversy regarding the role of colloids in the resuscitation of trauma patients has persisted for the past century without a clear resolution. Recently, the early treatment goals of traumatic hypovolemic shock have changed with an emphasis on minimal intravenous fluid administration and the avoidance of over-resuscitation. While some clinicians see a role for colloids in this model, others have become wary as evidence mounts against the efficacy and safety of hydroxyethyl starch and human albumin in critically ill patients. We reviewed the history and fundamentals of the crystalloid versus colloid debate and explored the relevant findings from the prominent non-trauma literature with attention to their applicability in the trauma population. Critical appraisal of the trauma-specific colloid literature is offered with a focus on study design and practical utility. Finally, we offer recommendations about the rational selection of fluids for clinicians who treat these challenging patients.

The Ryder Cognitive Aid Checklist for Trauma Anesthesia

Despite mixed results regarding the clinical utility of checklists, the anesthesia community is increasingly interested in advancing research around this important topic. Although several checklists have been developed to address routine perioperative care, few checklists in the anesthesia literature specifically target the management of trauma patients. We adapted a recently published “trauma and emergency checklist” for the initial phase of resuscitation and anesthesia of critically ill trauma patients into an applicable perioperative cognitive aid in the form of a pictogram that can be downloaded by the medical community. The Ryder Cognitive Aid Checklist for Trauma Anesthesia is a letter-sized, full-color document consisting of 2 pages and 5 sections. This cognitive aid describes the essential steps to be performed: before patient arrival to the hospital, on patient arrival to the hospital, during the initial assessment and management, during the resuscitation phase, and for postoperative care. A brief online survey is also presented to obtain feedback for improvement of this tool. The variability in utility of cognitive aids may be because of the specific clinical task being performed, the skill level of the individuals using the cognitive aid, overall quality of the cognitive aid, or organizational challenges. Once optimized, future research should be focused at ensuring successful implementation and customization of this tool.

Resuscitation in a Multiple Casualty Event

A major weakness in the emergency medical response to multiple casualty events continues to be the resuscitation component, which should consist of the systematic application of basic, advanced, and prolonged life support and definitive care within 24 hours. There have been major advances in emergency medical care over the last decade, including the feasibility of point-of-care ultrasound to aid in rapid assessment of injuries in the field, damage control resuscitation, and resuscitative surgery protocols, delivered by small trauma/resuscitation teams equipped with regional anesthesia capability for rapid deployment. Widespread adoption of these best practices may improve the delivery of resuscitative care in future multiple casualty events.

INCREASED RISK OF FIBRINOLYSIS SHUTDOWN AMONG SEVERELY INJURED TRAUMA PATIENTS RECEIVING TRANEXAMIC ACID

BACKGROUND The association between tranexamic acid (TXA) and fibrinolysis shutdown is unknown. We hypothesize that TXA is associated with fibrinolysis shutdown in critically injured trauma patients. METHODS Two hundred eighteen critically injured adults admitted to the intensive care unit at an urban Level I trauma center from August 2011 to January 2015 who had thromboelastography performed upon intensive care unit admission were reviewed. Groups were stratified based on fibrinolysis shutdown, which was defined as LY30 of 0.8% or less. Continuous variables were expressed as mean ± standard deviation or median (interquartile range). Poisson regression analysis was used to determine predictors of shutdown. RESULTS Patients were age 46 ± 18 years, 81% male, 75% blunt trauma, Injury Severity Score of 28 ± 13, 16% received TXA, 64% developed fibrinolysis shutdown, and mortality was 15%. In the first 24 hours, 4 (2–9) units packed red blood cells and 2 (0–6) units fresh frozen plasma were administered. Those with shutdown had worse initial systolic blood pressure (114 ± 38 mm Hg vs. 129 ± 43 mm Hg, p = 0.006) and base deficit (−5 ± 6 mEq/L vs −3 ± 5 mEq/L, p = 0.013); received more packed red blood cells [6 (2–11) vs. 2 (1–5) units, p < 0.0001], and fresh frozen plasma [3 (0–8) vs. 0 (0–4) units, p < 0.0001]; and more often received TXA (23% vs. 4%, p <0.0001). After controlling for confounders, TXA (relative risk, 1.35; 95% confidence interval, 1.10–1.64; p = 0.004) and cryoprecipitate transfusion (relative risk, 1.29; 95% confidence interval, 1.07–1.56; p = 0.007) were independently associated with fibrinolysis shutdown. CONCLUSION Patients who received TXA were at increased risk of fibrinolysis shutdown compared with patients who did not receive TXA. We recommend that administration of TXA be limited to severely injured patients with evidence of hyperfibrinolysis and recommend caution in those with evidence of fibrinolysis shutdown. LEVEL OF EVIDENCE Therapeutic, level III.

Auditory Icon Alarms Are More Accurately and Quickly Identified than Current Standard Melodic Alarms in a Simulated Clinical Setting

Background: Current standard audible medical alarms are difficult to learn and distinguish from one another. Auditory icons represent a new type of alarm that has been shown to be easier to learn and identify in laboratory settings by lay subjects. In this study, we test the hypothesis that icon alarms are easier to learn and identify than standard alarms by anesthesia providers in a simulated clinical setting. Methods: Twenty anesthesia providers were assigned to standard or icon groups. Experiments were conducted in a simulated intensive care unit. After a brief group-specific alarm orientation, subjects identified patient-associated alarm sounds during the simulation and logged responses via a tablet computer. Each subject participated in the simulation twice and was exposed to 32 alarm annunciations. Primary outcome measures were response accuracy and response times. Secondary outcomes included assessments of perceived fatigue and task load. Results: Overall accuracy rate in the standard alarm group was 43% (mean) and in the icon group was 88% (mean). Subjects in the icon group were 26.1 (odds ratio [98.75% CI, 8.4 to 81.5; P < 0.001]) times more likely to correctly identify an alarm. Response times in the icon group were shorter than in the standard alarm group (12 vs. 15 s, difference 3 s [98.75% CI ,1 to 5; P < 0.001]). Conclusions: Under our simulated conditions, anesthesia providers more correctly and quickly identified icon alarms than standard alarms. Subjects were more likely to perceive higher fatigue and task load when using current standard alarms than icon alarms.

Factors Affecting Acoustics and Speech Intelligibility in the Operating Room: Size Matters

INTRODUCTION: Noise in health care settings has increased since 1960 and represents a significant source of dissatisfaction among staff and patients and risk to patient safety. Operating rooms (ORs) in which effective communication is crucial are particularly noisy. Speech intelligibility is impacted by noise, room architecture, and acoustics. For example, sound reverberation time (RT60) increases with room size, which can negatively impact intelligibility, while room objects are hypothesized to have the opposite effect. We explored these relationships by investigating room construction and acoustics of the surgical suites at our institution. METHODS: We studied our ORs during times of nonuse. Room dimensions were measured to calculate room volumes (VR). Room content was assessed by estimating size and assigning items into 5 volume categories to arrive at an adjusted room content volume (VC) metric. Psychoacoustic analyses were performed by playing sweep tones from a speaker and recording the impulse responses (ie, resulting sound fields) from 3 locations in each room. The recordings were used to calculate 6 psychoacoustic indices of intelligibility. Multiple linear regression was performed using VR and VC as predictor variables and each intelligibility index as an outcome variable. RESULTS: A total of 40 ORs were studied. The surgical suites were characterized by a large degree of construction and surface finish heterogeneity and varied in size from 71.2 to 196.4 m3 (average VR = 131.1 [34.2] m3). An insignificant correlation was observed between VR and VC (Pearson correlation = 0.223, P = .166). Multiple linear regression model fits and &bgr; coefficients for VR were highly significant for each of the intelligibility indices and were best for RT60 (R2 = 0.666, F(2, 37) = 39.9, P < .0001). For Dmax (maximum distance where there is <15% loss of consonant articulation), both VR and VC &bgr; coefficients were significant. For RT60 and Dmax, after controlling for VC, partial correlations were 0.825 (P < .0001) and 0.718 (P < .0001), respectively, while after controlling for VR, partial correlations were −0.322 (P = .169) and 0.381 (P < .05), respectively. CONCLUSIONS: Our results suggest that the size and contents of an OR can predict a range of psychoacoustic indices of speech intelligibility. Specifically, increasing OR size correlated with worse speech intelligibility, while increasing amounts of OR contents correlated with improved speech intelligibility. This study provides valuable descriptive data and a predictive method for identifying existing ORs that may benefit from acoustic modifiers (eg, sound absorption panels). Additionally, it suggests that room dimensions and projected clinical use should be considered during the design phase of OR suites to optimize acoustic performance.