Enhanced Training Benefits of Video Recording Surgery With Automated Hand Motion Analysis.

BACKGROUND: Hand motion analysis by video recording during surgery has potential for evaluation of surgical performance. The aim was to identify how technical skill during open surgery can be measured unobtrusively by video recording during a surgical procedure. We hypothesized that procedural-step timing, hand movements, instrument use and Shannon entropy differ with expertise and training and are concordant with a performance-based validated individual procedure score. METHODS: Surgeon and non-surgeon participants with varying training and levels of expertise were video recorded performing axillary artery exposure and control (AA) on un-preserved cadavers. Color-coded gloves permitted motion-tracking and automated extraction of entropy data from recordings. Timing and instrument-use metrics were obtained through observational video reviews. Shannon entropy measured speed, acceleration and direction by computer-vision algorithms. Findings were compared with individual procedure score for AA performance RESULTS: Experts had lowest entropy values, idle time, active time and shorter time to divide pectoralis minor, using fewer instruments. Residents improved with training, without reaching expert levels, and showed deterioration 12-18 months later. Individual procedure scores mirrored these results. Non-surgeons differed substantially. CONCLUSIONS: Hand motion entropy and timing metrics discriminate levels of surgical skill and training, and these findings are congruent with individual procedure score evaluations. These measures can be collected using consumer-level cameras and analyzed automatically with free software. Hand motion with video timing data may have widespread application to evaluate resident performance and can contribute to the range of evaluation and testing modalities available to educators, training course designers and surgical quality assurance programs.

Handheld Tissue Oximetry for the Prehospital Detection of Shock and Need for Lifesaving Interventions: Technology in Search of an Indication?

Improved prehospital methods for assessing the need for lifesaving interventions (LSIs) are needed to gain critical lead time in the care of the injured. We hypothesized that threshold values using prehospital handheld tissue oximetry would detect occult shock and predict LSI requirements. This was a prospective observational study of adult trauma patients emergently transported by helicopter. Patients were monitored with a handheld tissue oximeter (InSpectra Spot Check; Hutchinson Technology Inc, Hutchinson, MN), continuous vital signs, and 21 laboratory measurements obtained both in the field with a portable analyzer and at the time of admission. Shock was defined as base excess ≥ 4 or lactate > 3 mmol/L. Eighty-eight patients were enrolled with a median Injury Severity Score of 16 (interquartile range, 5-29). The median hemoglobin saturation in the capillaries, venules, and arterioles (StO2) value for all patients was 82% (interquartile range, 76%-87%; range, 42%-98%). StO2 was abnormal (< 75%) in 18 patients (20%). Eight were hypotensive (9%) and had laboratory-confirmed evidence of occult shock. StO2 correlated poorly with shock threshold laboratory values (r = -0.17; 95% confidence interval, -0.33 to 1.0; P = .94). The area under the receiver operating curve was 0.51 (95% confidence interval, 0.39-0.63) for StO2 < 75% and laboratory-confirmed shock. StO2 was not associated with LSI need on admission when adjusted for multiple covariates, nor was it independently associated with death. Handheld tissue oximetry was not sensitive or specific for identifying patients with prehospital occult shock. These results do not support prehospital StO2 monitoring despite its inclusion in several published guidelines.

Repeat lactate level predicts mortality better than rate of clearance.

BACKGROUND: Lactate clearance has been developed into a marker of resuscitation in trauma, but no study has compared the predictive power of the various clearance calculations. Our objective was to determine which method of calculating lactate clearance best predicted 24-hour and in-hospital mortality after injury. STUDY DESIGN: Retrospective chart review of patients admitted to a Level-1 trauma center directly from the scene of injury from 2010 to 2013 who survived >15min, had an elevated lactate at admission (≥3mmol/L), followed by another measurement within 24h of admission. Lactate clearance was calculated using five models: actual value of the repeat level, absolute clearance, relative clearance, absolute rate, and relative rate. Models were compared using the areas under the respective receiver operating curves (AUCs), with an endpoint of death at 24h and in-hospital mortality. RESULTS: 3910 patients had an elevated admission lactate concentration on admission (mean=5.6±3.0mmol/L) followed by a second measurement (2.7±1.8mmol/L). Repeat absolute measurement best predicted 24-hour (AUC=0.85, 95% CI: 0.84-0.86) and in-hospital death (AUC=0.77; 95% CI, 0.76-0.78). Relative clearance was the best model of lactate clearance (AUC=0.77, 95% CI: 0.75-0.78 and AUC=0.705, 95% CI: 0.69-72, respectively) (p<0.0001 for each). A sensitivity analysis using a range of initial lactate measures yielded similar results. CONCLUSIONS: The absolute value of the repeat lactate measurement had the greatest ability to predict mortality in injured patients undergoing resuscitation.

Reliable Collection of Real-Time Patient Physiologic Data from less Reliable Networks: a "Monitor of Monitors" System (MoMs).

Research and practice based on automated electronic patient monitoring and data collection systems is significantly limited by system down time. We asked whether a triple-redundant Monitor of Monitors System (MoMs) to collect and summarize key information from system-wide data sources could achieve high fault tolerance, early diagnosis of system failure, and improve data collection rates. In our Level I trauma center, patient vital signs(VS) monitors were networked to collect real time patient physiologic data streams from 94 bed units in our various resuscitation, operating, and critical care units. To minimize the impact of server collection failure, three BedMaster® VS servers were used in parallel to collect data from all bed units. To locate and diagnose system failures, we summarized critical information from high throughput datastreams in real-time in a dashboard viewer and compared the before and post MoMs phases to evaluate data collection performance as availability time, active collection rates, and gap duration, occurrence, and categories. Single-server collection rates in the 3-month period before MoMs deployment ranged from 27.8 % to 40.5 % with combined 79.1 % collection rate. Reasons for gaps included collection server failure, software instability, individual bed setting inconsistency, and monitor servicing. In the 6-month post MoMs deployment period, average collection rates were 99.9 %. A triple redundant patient data collection system with real-time diagnostic information summarization and representation improved the reliability of massive clinical data collection to nearly 100 % in a Level I trauma center. Such data collection framework may also increase the automation level of hospital-wise information aggregation for optimal allocation of health care resources.

Trends of Hemoglobin Oximetry: Do They Help Predict Blood Transfusion During Trauma Patient Resuscitation?

BACKGROUND: A noninvasive decision support tool for emergency transfusion would benefit triage and resuscitation. We tested whether 15 minutes of continuous pulse oximetry-derived hemoglobin measurements (SpHb) predict emergency blood transfusion better than conventional oximetry, vital signs, and invasive point-of-admission (POA) laboratory testing. We hypothesized that the trends in noninvasive SpHb features monitored for 15 minutes predict emergency transfusion better than pulse oximetry, shock index (SI = heart rate/systolic blood pressure), or routine POA laboratory measures. METHODS: We enrolled direct trauma patient admissions ≥18 years with prehospital SI ≥0.62, collected vital signs (continuous SpHb and conventional pulse oximetry, heart rate, and blood pressure) for 15 minutes after admission, and recorded transfusion (packed red blood cells [pRBCs]) within 1 to 3, 1 to 6, and 1 to 12 hours of admission. One blood sample was drawn during the first 15 minutes. The laboratory Hb was compared with its corresponding SpHb reading for numerical, clinical, and prediction difference. Ten prediction models for transfusion, including combinations of prehospital vital signs, SpHb, conventional oximetry, and routine POA, were selected by stepwise logistic regression. Predictions were compared via area under the receiver operating characteristic curve by the DeLong method. RESULTS: A total of 677 trauma patients were enrolled in the study. The prediction performance of the models, including POA laboratory values and SI (and the need for blood pressure), was better than those without POA values or SI. In predicting pRBC 1- to 3-hour transfusion, adding SpHb features (receiver operating characteristic curve [ROC] = 0.65; 95% confidence interval [CI], 0.53-0.77) does not improve ROC from the base model (ROC = 0.64; 95% CI, 0.52-0.76) with P = 0.48. Adding POA laboratory Hb features (ROC = 0.72; 95% CI, 0.60-0.84) also does not improve prediction performance (P = 0.18). Other POA laboratory testing predicted emergency blood use with ROC of 0.88 (95% CI, 0.81-0.96), significantly better than the use of SpHb (P = 0.00084) and laboratory Hb (P = 0.0068). CONCLUSIONS: SpHb added no benefit over conventional oximetry to predict urgent pRBC transfusion for trauma patients. Both models containing POA laboratory test features performed better at predicting pRBC use than prehospital SI, the current best noninvasive vital signs transfusion predictor.

Computer Modelling Using Prehospital Vitals Predicts Transfusion and Mortality.

OBJECTIVE: Test computer-assisted modeling techniques using prehospital vital signs of injured patients to predict emergency transfusion requirements, number of intensive care days, and mortality, compared to vital signs alone. METHODS: This single-center retrospective analysis of 17,988 trauma patients used vital signs data collected between 2006 and 2012 to predict which patients would receive transfusion, require 3 or more days of intensive care, or die. Standard transmitted prehospital vital signs (heart rate, blood pressure, shock index, and respiratory rate) were used to create a regression model (PH-VS) that was internally validated and evaluated using area under the receiver operating curve (AUROC). Transfusion records were matched with blood bank records. Documentation of death and duration of intensive care were obtained from the trauma registry. RESULTS: During the course of their hospital stay, 720 of the 17,988 patients in the study population died (4%), 2,266 (12.6%) required at least a 3-day stay in the intensive care unit (ICU), 1,171 (6.5%) required transfusions, and 210 (1.2%) received massive transfusions. The PH-VS model significantly outperformed any individual vital sign across all outcomes (average AUROC = 0.82), The PH-VS model correctly predicted that 512 of 777 (65.9%) and 580 of 931 (62.3%) patients in the study population would receive transfusions within the first 2 and 6 hours of admission, respectively. CONCLUSIONS: The predictive ability of individual vital signs to predict outcomes is significantly enhanced with the model. This could support prehospital triage by enhancing decision makers' ability to match critically injured patients with appropriate resources with minimal delays.

Perception does not equal reality for resident vascular trauma skills.

BACKGROUND: Experience with the management of vascular trauma by senior surgical residents is increasingly limited. When queried about their understanding of anatomy and ability to perform specific vascular exposures, residents express a moderately high level of confidence. We hypothesized that this perception does not equal reality. METHODS: A total of 42 senior surgical residents participating in an ongoing validation study of the Advanced Surgical Skills for Exposures in Trauma course were asked to self-assess their baseline (precourse) confidence of their understanding of the anatomy required to perform and their ability to perform exposure and control of the axillary, brachial, and femoral arteries, as well as lower extremity fasciotomy using a 5-point Likert scale. Residents then performed the four procedures on a fresh cadaver model and were scored in real time by experts using a global assessment of anatomic knowledge and readiness to perform." The Student t-test was used with α set at P < 0.05. RESULTS: Residents consistently rated their understanding of anatomy and their ability to perform the procedures significantly higher than expert evaluator ultimately scored them. Evaluators also deemed that residents would be unable to perform without help 65%-86% of the time. CONCLUSIONS: Senior residents are ill-prepared to perform the procedures studied and have an unwarranted confidence in their knowledge and abilities. Perception clearly does not equal reality in preparing these trainees to perform as advertized. The low global scores for anatomy and performance should be a wake-up call for surgical educators prompting curricular reform and evaluation.

S-100ß does not predict outcome after mild traumatic brain injury.

OBJECTIVE: To determine the usefulness of S-100ß, a marker for central nervous system damage, in the prediction of long-term outcomes after mild traumatic brain injury (MTBI) Hypothesis: Mid- and long-term outcomes of MTBI (i.e. 3, 6 and 12 months post-injury and return-to-work or school (RTWS)) may be predicted based on pre-injury and injury factors as well as S-100ß. METHODS: MTBI subjects without abnormal brain computed tomography requiring intervention, focal neurological deficits, seizures, amnesia > 24 hours and severe or multiple injuries were recruited at a level I trauma centre. Admission S-100ß measurements and baseline Concussion Symptom Checklist were obtained. Symptoms and RTWS were re-assessed at follow-up visits (3-10 days and 3, 6 and 12 months). Outcomes included number of symptoms and RTWS at follow-up. Chi-square tests, linear and logistic regression models were used and p < 0.05 was considered statistically significant. RESULTS: One hundred and fifty of 180 study subjects had S-100ß results. Eleven per cent were unable to RTWS at 12 months. S-100ß levels were not associated with post-concussive symptomatology at follow-up. In addition, no association was found between S-100ß levels and RTWS. CONCLUSION: Amongst MTBI patients, S-100ß levels are not associated with prolonged post-concussive syndrome or the inability to RTWS.

Full of sound and fury, signifying nothing: burden of transient noncritical monitor alarms in a trauma resuscitation unit.

We examined the types of patient monitor alarms encountered in the trauma resuscitation unit of a major level 1 trauma center. Over a 1-year period, 316688 alarms were recorded for 6701 trauma patients (47 alarms/patient). Alarms were more frequent among patients with a Glasgow Coma Scale of 8 or less. Only 2.4% of all alarms were classified as "patient crisis," with the rest in the presumably less critical categories "patient advisory," "patient warning," and "system warning." Nearly half of alarms were ≤5 seconds in duration. In this patient population, a 2-second delay would reduce alarms by 25%, and a delay of 5 seconds would reduce all alarms by 49%.

Re-analysis of the PolyHeme Phase III trial dataset: Lessons for future haemoglobin-based oxygen carrier trauma trials.

INTRODUCTION: To assist design of future HBOC clinical trials for pre-hospital and prolonged field care, the haemoglobin-based-oxygen carrier (HBOC) Phase III trauma trial database comparing PolyHeme to blood transfusion was re-analysed to identify causes of adverse early outcomes versus the 30-day mortality outcome of the original trial. We questioned if failure of PolyHeme (10 g/dl) to increase haemoglobin concentration and dilutional coagulopathy versus blood, caused higher Day 1 mortality in the PolyHeme arm of the trial. METHODS: New analyses of the original trial database, including Fisher's exact test, examined impact of interval changes in total haemoglobin [THb], coagulation, fluid volumes administered and mortality on Day 1 in the Control (pre-hospital crystalloids, then blood after trauma centre admission) and PolyHeme arms of the trial. RESULTS: Admission [THb] was significantly greater (p<0.05) in PolyHeme (12.3 [SD = 1.8] g/dl) versus Control (11.5 [SD= 2.9] g/dl) patients. This early [THb] advantage was reversed within 6 h. Early mortality was negatively correlated with [THb] and maximum 1.4 h after hospital admission (17/365 for Control vs. 5/349 for PolyHeme). The mortality trend began reversing, when Control arm received blood. Coagulopathy was more common in the PolyHeme arm. Mortality rate was 2-fold greater for patients with coagulopathy in the control arm (18% vs. 9%, p = 0.1008) and 4-fold greater in PolyHeme arm (33% vs. 8.5%, p < 0.001). In a subgroup analysis of patients with major haemorrhage (n = 55), mortality was significantly higher in PolyHeme patients [12/26 (46.2%) versus 4/29 (13.8%) in control cohort (p = 0.018)], related to mean 10 liters more IV fluid administration and more severe anaemia (6.2 g/dL vs. 9.2 g/dL) in the PolyHeme cohort. CONCLUSIONS: PolyHeme (10 g/dL) diminished pre-hospital anaemia. The inability of PolyHeme to reverse acute anaemia in a subset of major haemorrhage patients was due to volume overload secondary to high PolyHeme doses, resulting in dilution of clotting factors and low circulating THb (versus transfused controls) during the first 12 h of the trial. Haemodilution was associated with prolonged administration of PolyHeme, while blood transfusion was available to Control patients following hospital admission. Coagulopathy exacerbated bleeding, anaemia, contributing to excess mortality in the PolyHeme arm. Future trials for prolonged field care should evaluate HBOC with higher haemoglobin concentration, lower volume administration and transition upon trauma centre admission to blood plus coagulation factors or whole blood.

Virtual reality and haptic interfaces for civilian and military open trauma surgery training: A systematic review.

OBJECTIVE: Virtual (VR), augmented (AR), mixed reality (MR) and haptic interfaces make additional avenues available for surgeon assessment, guidance and training. We evaluated applications for open trauma and emergency surgery to address the question: Have new computer-supported interface developments occurred that could improve trauma training for civilian and military surgeons performing open, emergency, non-laparoscopic surgery? DESIGN: Systematic literature review. SETTING AND PARTICIPANTS: Faculty, University of Maryland School of Medicine, Baltimore., Maryland; Womack Army Medical Center, Fort Bragg, North Carolina; Temple University, Philadelphia, Pennsylvania; Uniformed Services University of Health Sciences, and Walter Reed National Military Medical Center, Bethesda, Maryland. METHODS: Structured literature searches identified studies using terms for virtual, augmented, mixed reality and haptics, as well as specific procedures in trauma training courses. Reporting bias was assessed. Study quality was evaluated by the Kirkpatrick's Level of evidence and the Machine Learning to Asses Surgical Expertise (MLASE) score. RESULTS: Of 422 papers identified, 14 met inclusion criteria, included 282 enrolled subjects, 20% were surgeons, the remainder students, medics and non-surgeon physicians. Study design was poor and sample sizes were low. No data analyses were beyond descriptive and the highest outcome types were procedural success, subjective self-reports, except three studies used validated metrics. Among the 14 studies, Kirkpatrick's level of evidence was level zero in five studies, level 1 in 8 and level 2 in one. Only one study had MLASE Score greater than 9/20. There was a high risk of bias in 6 studies, uncertain bias in 5 studies and low risk of bias in 3 studies. CONCLUSIONS: There was inadequate evidence that VR,MR,AR or haptic interfaces can facilitate training for open trauma surgery or replace cadavers. Because of limited testing in surgeons, deficient study and technology design, risk of reporting bias, no current well-designed studies of computer-supported technologies have shown benefit for open trauma, emergency surgery nor has their use shown improved patient outcomes. Larger more rigorously designed studies and evaluations by experienced surgeons are required for a greater variety of procedures and skills. COMPETENCIES: Medical Knowledge, Practice Based Learning and Improvement, Patient Care, Systems-Based Practice.

Comparison of massive and emergency transfusion prediction scoring systems after trauma with a new Bleeding Risk Index score applied in-flight.

BACKGROUND: Assessment of blood consumption (ABC), shock index (SI), and Revised Trauma Score (RTS) are used to estimate the need for blood transfusion and triage. We compared Bleeding Risk Index (BRI) score calculated with trauma patient noninvasive vital signs and hypothesized that prehospital BRI has better performance compared with ABC, RTS, and SI for predicting the need for emergent and massive transfusion (MT). METHODS: We analyzed 2-year in-flight data from adult trauma patients transported directly to a Level I trauma center via helicopter. The BRI scores 0 to 1 were derived from continuous features of photoplethymographic and electrocardiographic waveforms, oximetry values, blood pressure trends. The ABC, RTS, and SI were calculated using admission data. The area under the receiver operating characteristic curve (AUROC) with 95% confidence interval (CI) was calculated for predictions of critical administration threshold (CAT, ≥3 units of blood in the first hour) or MT (≥10 units of blood in the first 24 hours). DeLong's method was used to compare AUROCs for different scoring systems. p < 0.05 was considered statistically significant. RESULTS: Among 1,396 patients, age was 46.5 ± 20.1 years (SD), 67.1% were male. The MT rate was 3.2% and CAT was 7.6%, most (92.8%) were blunt injury. Mortality was 6.6%. Scene arrival to hospital time was 35.3 ± (10.5) minutes. The BRI prediction of MT with AUROC 0.92 (95% CI, 0.89-0.95) was significantly better than ABC, SI, or RTS (AUROCs = 0.80, 0.83, 0.78, respectively; 95% CIs 0.73-0.87, 0.76-0.90, 0.71-0.85, respectively). The BRI prediction of CAT had an AUROC of 0.91 (95% CI, 0.86-0.94), which was significantly better than ABC (AUROC, 077; 95% CI, 0.73-0.82) or RTS (AUROC, 0.79; 95% CI, 0.74-0.83) and better than SI (AUROC, 0.85; 95% CI, 0.80-0.89). The BRI score threshold for optimal prediction of CAT was 0.25 and for MT was 0.28. CONCLUSION: The autonomous continuous noninvasive patient vital signs-based BRI score performs better than ABC, RTS, and SI predictions of MT and CAT. Bleeding Risk Index does not require additional data entry or expert interpretation. LEVEL OF EVIDENCE: Prognostic test, level III.

When blood is not an option: factors affecting survival after the use of a hemoglobin-based oxygen carrier in 54 patients with life-threatening anemia.

BACKGROUND: In consenting Jehovah's Witness patients and others for whom blood is contraindicated or not available, hemoglobin-based oxygen carrier (HBOC)-201 may enable survival in acutely anemic patients while underlying conditions are treated. METHODS: Survival factors were identified in a multicenter, unblinded series of severely anemic "compassionate use" patients receiving available standard treatment plus consultant-supported HBOC-201 administration by novice users. Predictors of outcome were sought and compared between survivors and nonsurvivors. A compound variable, hemoglobin-duration deficit product was used to describe the interactive clinical effects of severity and duration of anemia. Mortality,correlations between patient characteristics, and survival to hospital discharge were determined from patient records. RESULTS: Fifty-four patients (median age 50 years) with life-threatening anemia (median hemoglobin concentration at time of request = 4 g/dL) received 60 to 300 g HBOC-201.Twenty-three patients (41.8%) were discharged. Intraoperative blood loss (45%), malignancy(18%), and acute hemolysis (13%) were the prevailing reasons for anemia. Time from onset of anemia (< or = 8 g/dL) to HBOC-201 infusion was shorter for survivors than nonsurvivors (3.2 vs 4.4 days, P = 0.027). Mean hemoglobin levels before HBOC-201 infusion in survivors and nonsurvivors were 4.5 and 3.8 g/dL, respectively (P = 0.120). No serious adverse event was attributed to HBOC-201. The hemoglobin-duration deficit product separated survivors from nonsurvivors. Cancer and renal disease were associated with nonsurvival. CONCLUSION: Earlier, compared with later, administration by inexperienced users of HBOC-201 to patients with anemia was associated with improved chances of survival of acutely bleeding and hemolyzing patients. Survival was more likely if the duration and magnitude of low hemoglobin was minimized before treatment with HBOC-201.

Scoping Evidence Review on Training and Skills Assessment for Open Emergency Surgery.

OBJECTIVE: Scope evidence on technical performance metrics for open emergency surgery. Identify surgical performance metrics and procedures used in trauma training courses. DESIGN: Structured literature searches of electronic databases were conducted from January 2010 to December 2019 to identify systematic reviews of tools to measure surgical skills employed in vascular or trauma surgery evaluation and training. SETTING AND PARTICIPANTS: Faculty of Shock Trauma Anesthesiology Research Center, University of Maryland School of Medicine, Uniformed Services University of Health Sciences, Bethesda, Maryland and Implementation Science, King's College, London. RESULTS: The evidence from 21 systematic reviews including over 54,000 subjects enrolled into over 840 eligible studies, identified that the Objective Structured Assessment of Technical Skill was used for elective surgery not for emergency trauma and vascular control surgery procedures. The Individual Procedure Score (IPS), used to evaluate emergency trauma procedures performed before and after training, distinguished performance of residents from experts and practicing surgeons. IPS predicted surgeons who make critical errors and need remediation interventions. No metrics showed Kirkpatrick's Level 4 evidence of technical skills training benefit to emergency surgery outcomes. CONCLUSIONS: Expert benchmarks, errors, complication rates, task completion time, task-specific checklists, global rating scales, Objective Structured Assessment of Technical Skills, and IPS were found to identify surgeons, at all levels of seniority, who are in need of remediation of technical skills for open surgical hemorrhage control. Large-scale, multicenter studies are needed to evaluate any benefit of trauma technical skills training on patient outcomes.

Prehospital Point of Care Testing for the Early Detection of Shock and Prediction of Lifesaving Interventions.

INTRODUCTION: Early diagnosis and treatment are essential for enhancing outcomes for the traumatically injured. In this prospective prehospital observational study, we hypothesized that a variety of laboratory results measured in the prehospital environment would predict both the presence of early shock and the need for lifesaving interventions (LSIs) for adult patients with traumatic injuries. METHODS: Adult trauma patients flown by a helicopter emergency medical service were prospectively enrolled. Using an i-STAT portable analyzer, data from 16 laboratory tests were collected. Vital signs data were also collected. Outcomes of interest included detection of shock, mortality, and requirement for LSIs. Logistic regression, including a Bayesian analysis, was performed. RESULTS: Among 300 patients screened for enrollment, 261 had complete laboratory data for analysis. The majority of patients were male (75%) with blunt trauma (91.2%). The median injury severity score was 29 (IQR, 25-75) and overall mortality was 4.6%. A total of 170 LSIs were performed. The median lactate for patients who required an LSI was 4.1 (IQR, 3-5.4). The odds of requiring an LSI within the first hour of admission to the trauma center was highly associated with increases in lactate and glucose. A lactate level > 4 mmol/L was statistically associated with greater sensitivity and specificity for predicting the need for a LSI compared with shock index. CONCLUSIONS: In this prospective observational trial, lactate outperformed static vital signs, including shock index, for detecting shock and predicting the need for LSIs. A lactate level > 4 mmol/L was found to be highly associated with the need for LSIs.

Users Guide to Pitfalls and Lessons Learned About HBOC-201 During Clinical Trials, Expanded Access, and Clinical Use in 1,701 Patients.

Lessons learned during 1,701 clinical uses of HBOC-201, a polymerized bovine hemoglobin-based oxygen carrier (HBOC), were identified to provide management lessons and training material for future clinical trials and use. HBOC-201 contains 13 g/dL hemoglobin (Hb), is iso-oncotic, stable at 2°C to 30°C with shelf-life of 3 years, requires no cross-matching with half-life of 19 h, and plasma volume distribution. Adverse effects include increased blood pressure, oliguria, gastrointestinal (GI) symptoms, yellow skin and scleral discoloration, decreased pulse oximetry measurements, and transient increases in methemoglobin, hepatic, and pancreatic enzymes. There was no cardiotoxicity. Elevations in blood pressure were transient and were managed with vasodilators. Oliguria was of limited duration. GI symptoms were treated with smooth muscle relaxants. Yellow skin and sclera were self-limiting, caused by Hb metabolism. The most important clinical management errors were lack of understanding of volume expansion effects and the half-life properties of HBOC-201, and failure to repeat infusions. Early use of HBOC-201 for Expanded Access when Hb less than 5 g/dL optimized survival and minimized advanced resource utilization. For phase 3 trials, there was transfusion avoidance of 96% for 24 h, 70% for 1 week, with no difference in serious adverse events or mortality whether patients received at most 10 bags HBOC-201 or at most 3 units blood. More nonserious events occurred with HBOC-201. Age, history of cardiac disease, and Hb deficit, but not randomization to HBOC-201, were significantly predictive of cardiac ischemic events. Administration of HBOC-201 in1,701 humans showed it was well tolerated in a wide range of doses and clinical settings. HBOC-201 should be considered when blood is not available or an option.

Relative Efficacies of HBOC-201 and Polyheme to Increase Oxygen Transport Compared to Blood and Crystalloids.

BACKGROUND: Because total hemoglobin in circulation ([THb]) is an established predictor of clinical outcomes in anemic individuals, the relative efficacies of resuscitation fluids to increase [THb] can be used to design better hemoglobin-based oxygen carrier (HBOC) clinical trials. METHODS: Expected efficacies of HBOC-201 (13 g Hb/dL) and packed red blood cells (RBCs) (packed red blood cells [pRBCs], 24 g Hb/dL) to increase [THb] were calculated and interpreted in the context of severe adverse events (SAEs) in the HEM-0115 phase III clinical trial.The PolyHeme phase III clinical trial compared the HBOC, PolyHeme (10 g Hb/dL), with crystalloid control prehospital and packed RBCs in hospital. The comparative abilities of these resuscitation fluids to maintain [THb] were interpreted in the context of mortality. RESULTS: In HEM-0115, infusion of HBOC-201 increased [THb] by 0.18 ±â€Š0.03 g/dL (N=121) compared with 0.87 ±â€Š0.07 g/dL (n = 115) following one unit of pRBCs. These observed increases in [THb] were similar to expected increases for these fluids. Use of HBOC-201 was associated with 0.34 SAEs per patient compared with 0.25 SAEs per patient in the pRBC arm (P = 0.016).Hemoglobin Deficit was greater in HBOC-201-treated patients than in pRBC controls and emerged as a predictor of SAEs in a logistics model. Randomization to HBOC-201 had no power to predict SAEs.PolyHeme more effectively maintained [THb] than did crystalloid prior to arrival at hospital, associated with initially higher survival in the PolyHeme arm. Thereafter, PolyHeme subjects sustained lower [THb] and higher mortality than controls. CONCLUSION: Greater anemia in subjects randomized to HBOC-201 was consistent with the relative efficacies of HBOC-201 and pRBCs to increase [THb] and may have contributed to more SAEs in the HBOC arm of HEM-0115 and greater long-term mortality in the PolyHeme trial.

Critical errors in infrequently performed trauma procedures after training.

BACKGROUND: Critical errors increase postoperative morbidity and mortality. A trauma readiness index was used to evaluate critical errors in 4 trauma procedures. In comparison to practicing and expert surgeon benchmarks, we hypothesized that pretraining trauma readiness index including both vascular and nonvascular trauma surgical procedures can identify residents who will make critical errors. METHODS: In a prospective study, trained evaluators used a standardized script to evaluate performance of brachial, axillary, and femoral artery exposure and proximal control and lower-extremity fasciotomy on unpreserved cadavers. Forty residents were evaluated before and immediately after Advanced Surgical Skills for Exposure in Trauma training, and 38 were re-evaluated 14 months later. Residents were compared to 34 practicing surgeons evaluated once 30 months after training, and 10 experts. RESULTS: Resident trauma readiness index increased with training (P < .001), remained unchanged 14 month later and was higher, with lower variance than practicing surgeons (P < .05). Expert trauma readiness index was higher than residents (P < .004) and practicing surgeons (P < .001). Resident training decreased critical errors when evaluated immediately and 14 months after Advanced Surgical Skills for Exposure in Trauma training. Practicing surgeons had more critical errors and performance variability than residents or experts. Experts had 5 to 7 times better error recovery than practicing surgeons or residents. Trauma readiness index area under the receiver operating curve with Youden Index <0.60 or <6 decile in their cohort, predicts a surgeon will make a critical error. CONCLUSION: Low trauma readiness index was associated with critical errors occurring in all surgeon cohorts and can identify surgeons in need of remedial intervention.