Surgical resident technical skill self-evaluation: increased precision with training progression.

BACKGROUND: Surgical resident ability to accurately evaluate one's own skill level is an important part of educational growth. We aimed to determine if differences exist between self and observer technical skill evaluation of surgical residents performing a single procedure. MATERIALS AND METHODS: We prospectively enrolled 14 categorical general surgery residents (six post-graduate year [PGY] 1-2, three PGY 3, and five PGY 4-5). Over a 6-month period, following each laparoscopic cholecystectomy, residents and seven faculty each completed the Objective Structured Assessment of Technical Skills (OSATS). Spearman's coefficient was calculated for three groups: senior (PGY 4-5), PGY3, and junior (PGY 1-2). Rho (ρ) values greater than 0.8 were considered well correlated. RESULTS: Of the 125 paired assessments (resident-faculty each evaluating the same case), 58 were completed for senior residents, 54 for PGY3 residents, and 13 for junior residents. Using the mean from all OSATS categories, trainee self-evaluations correlated well to faculty (senior ρ 0.97, PGY3 ρ 0.9, junior ρ 0.9). When specific OSATS categories were analyzed, junior residents exhibited poor correlation in categories of respect for tissue (ρ -0.5), instrument handling (ρ 0.71), operative flow (ρ 0.41), use of assistants (ρ 0.05), procedural knowledge (ρ 0.32), and overall comfort with the procedure (ρ 0.73). PGY3 residents lacked correlation in two OSATS categories, operative flow (ρ 0.7) and procedural knowledge (ρ 0.2). Senior resident self-evaluations exhibited strong correlations to observers in all areas. CONCLUSIONS: Surgical residents improve technical skill self-awareness with progressive training. Less-experienced trainees have a tendency to over-or-underestimate technical skill.

In-flight ultrasound identification of pneumothorax.

Ultrasound is a standard adjunct to the initial evaluation of injured patients in the emergency department. We sought to evaluate the ability of prehospital, in-flight thoracic ultrasound to identify pneumothorax. Non-physician aeromedical providers were trained to perform and interpret thoracic ultrasound. All adult trauma patients and adult medical patients requiring endotracheal intubation underwent both in-flight and emergency department ultrasound evaluations. Findings were documented independently and reviewed to ensure quality and accuracy. Results were compared to chest X-ray and computed tomography (CT). One hundred forty-nine patients (136 trauma/13 medical) met inclusion criteria. Mean age was 44.4 (18-94) years; 69 % were male. Mean injury severity score was 17.68 (1-75), and mean chest injury score was 2.93 (0-6) in the injured group. Twenty pneumothoraces and one mainstem intubation were identified. Sixteen pneumothoraces were correctly identified in the field. A mainstem intubation was misinterpreted. When compared to chest CT (n = 116), prehospital ultrasound had a sensitivity of 68 % (95 % confidence interval (CI) 46-85 %), a specificity of 96 % (95 % CI 90-98 %), and an overall accuracy of 91 % (95 % CI 85-95 %). In comparison, emergency department (ED) ultrasound had a sensitivity of 84 % (95 % CI 62-94 %), specificity of 98 % (95 % CI 93-99 %), and an accuracy of 96 % (95 % CI 90-98 %). The unique characteristics of the aeromedical environment render the auditory element of a reliable physical exam impractical. Thoracic ultrasonography should be utilized to augment the diagnostic capabilities of prehospital aeromedical providers.

Emergent surgical airway: comparison of the three-step method and conventional cricothyroidotomy utilizing high-fidelity simulation.

BACKGROUND: Surgical airway creation has a high potential for disaster. Conventional methods can be cumbersome and require special instruments. A simple method utilizing three steps and readily available equipment exists, but has yet to be adequately tested. OBJECTIVE: Our objective was to compare conventional cricothyroidotomy with the three-step method utilizing high-fidelity simulation. METHODS: Utilizing a high-fidelity simulator, 12 experienced flight nurses and paramedics performed both methods after a didactic lecture, simulator briefing, and demonstration of each technique. Six participants performed the three-step method first, and the remaining 6 performed the conventional method first. Each participant was filmed and timed. We analyzed videos with respect to the number of hand repositions, number of airway instrumentations, and technical complications. Times to successful completion were measured from incision to balloon inflation. RESULTS: The three-step method was completed faster (52.1 s vs. 87.3 s; p = 0.007) as compared with conventional surgical cricothyroidotomy. The two methods did not differ statistically regarding number of hand movements (3.75 vs. 5.25; p = 0.12) or instrumentations of the airway (1.08 vs. 1.33; p = 0.07). The three-step method resulted in 100% successful airway placement on the first attempt, compared with 75% of the conventional method (p = 0.11). Technical complications occurred more with the conventional method (33% vs. 0%; p = 0.05). CONCLUSION: The three-step method, using an elastic bougie with an endotracheal tube, was shown to require fewer total hand movements, took less time to complete, resulted in more successful airway placement, and had fewer complications compared with traditional cricothyroidotomy.

Provider X-ray exposure in the trauma bay: results of a radiation field analysis.

Radiation exposure during trauma care has increased in recent years. Radiation risk to providers during the care of injured patients is not well defined. We aimed to gather environmental exposure data from dosimeters placed at fixed points in the trauma bay to act as surrogates for personnel radiation exposure during trauma team activations. Forty-four (44) radiation dosimeters were placed throughout a single trauma bay in a university level 1 trauma center. We analyzed shallow (SDE) and deep dose equivalents (DDE) over 6 months. We measured distance from the radiation source for each dosimeter. Four controls were included. We recorded patient injury and X-ray data for each patient. During the study period, 417 patients were evaluated in the trauma bay under study. Mean ISS was 14.3 (range 0-75). A total of 2,107 plain X-rays were taken, with a mean of 5.1 X-rays per patient (range 0-32). Extremity films were most often performed, followed by chest and shoulder films. No measurable dose was identified with the dosimeter controls. The majority (27, 68 %) of dosimeters registered the lowest doses (<1 mSv DDE). Five dosimeters revealed doses between 1 and 2 mSv DDE. Four dosimeters registered over 2 mSv DDE, with a mean DDE of 3 mSv. Distances of less than 5 ft from the radiation source had the highest DDE dose. Maximum annual occupational DDE dose is conventionally 50 mSv. None of the dosimeters registered DDE doses over 4.31 mSv during the study period, supporting low radiation risk to providers in the trauma bay.

Utility of Prehospital Quantitative End Tidal CO2?

INTRODUCTION: End tidal CO2 (ETCO2) has been established as a standard for confirmation of an airway, but its role is expanding. In certain settings ETCO2 closely approximates the partial pressure of arterial CO2 (PaCO2) and has been described as a tool to optimize a patient's ventilatory status. ETCO2 monitors are increasingly being used by EMS personnel to guide ventilation in the prehospital setting. Severely traumatized and burn patients represent a unique population to which this practice has not been validated. HYPOTHESIS: The sole use of ETCO2 to monitor ventilation may lead to avoidable respiratory acidosis. METHODS: A consecutive series of patients with burns or trauma intubated in the prehospital setting over a 24-month period were evaluated. Prehospital arrests were excluded. Absence of ETCO2 transport data and patients without an arterial blood gas (ABG) within 15 minutes of arrival were also excluded. Data collected included demographics, place and time of intubation, service performing intubation, ETCO2 maintained en-route to hospital, and ABG upon arrival. Further data included length of stay, mortality, and injury severity scores. RESULTS: One hundred sixty patients met the inclusion criteria. Prehospital ETCO2 did not correlate with measured PaCO2 (R2 = 0.08). Mean ETCO2 was significantly lower than mean PaCO2 (34 mmHg vs 44 mmHg, P < .005). Patients arriving acidotic were more likely to die. Mean pH on arrival for survivors and decedents was 7.32 and 7.19 respectively (P < .001). Mortality, acidosis, higher base deficits, and more severe injury patterns were all predictors for a worse correlation between ETCO2 and PaCO2 and increased mean difference between the two values. Decedents and patients presenting with a pH <7.2 demonstrated the greatest discrepancy between ETCO2 and PaCO2. The data suggest that patients may be hypoventilated by prehospital providers in order to obtain a prescribed ETCO2. CONCLUSION: ETCO2 is an inadequate tool for predicting PaCO2 or optimizing ventilation in severely injured patients. Adherence to current ETCO2 guidelines in the prehospital setting may contribute to acidosis and increased mortality. Consideration should be given to developing alternate protocols to guide ventilation of the severely injured in the prehospital setting.

Effect of Antibiotic Duration in Emergency General Surgery Patients with Intra-Abdominal Infection Managed with Open vs Closed Abdomen.

BACKGROUND: Data on duration of antibiotics in patients managed with an open abdomen (OA) due to intra-abdominal infection (IAI) are scarce. We hypothesized that patients with IAI managed with OA rather than closed abdomen (CA) would have higher rates of secondary infections (SIs) independent of the duration of the antibiotic treatment. METHODS: This was an observational, prospective, multicenter, international study of patients with IAI requiring laparotomy for source control. Demographic and antibiotic duration values were collected. Primary outcomes were SI (surgical site, bloodstream, pneumonia, urinary tract) and mortality. Statistical analysis included ANOVA, chi-square/Fisher's exact test, and logistic regression. RESULTS: Twenty-one centers contributed 752 patients. The average age was 59.6 years, 43.6% were women, and 43.9% were managed with OA. Overall mortality was 16.1%, with higher rates among OA patients (31.6% vs 4.4%, p < 0.001). OA patients had higher Sequential Organ Failure Assessment (4.7 vs 1.8, p < 0.001), American Society of Anesthesiologists Physical Status (3.6 vs 2.7, p < 0.001), and APACHE II scores (16.1 vs 9.4, p < 0.001). The mean duration of antibiotics was 6.5 days (8.0 OA vs 5.4 CA, p < 0.001). A total of 179 (23.8%) patients developed SI (33.1% OA vs 16.8% CA, p < 0.001). Longer antibiotic duration was associated with increased rates of SI: 1 to 2 days, 15.8%; 3 to 5 days, 20.4%; 6 to 14 days, 26.6%; and more than 14 days, 46.8% (p < 0.001). CONCLUSIONS: Patients with IAI managed with OA had higher rates of SI and increased mortality compared with CA. A prolonged duration of antibiotics was associated with increased rates of SI. Increased antibiotic duration is not associated with improved outcomes in patients with IAI and OA.

Prehospital end-tidal carbon dioxide is predictive of death and massive transfusion in injured patients: An Eastern Association for Surgery of Trauma multicenter trial.

BACKGROUND: Prehospital identification of the injured patient likely to require emergent care remains a challenge. End-tidal carbon dioxide (ETCO2) has been used in the prehospital setting to monitor respiratory physiology and confirmation of endotracheal tube placement. Low levels of ETCO2 have been demonstrated to correlate with injury severity and mortality in a number of in-hospital studies. We hypothesized that prehospital ETCO2 values would be predictive of mortality and need for massive transfusion (MT) in intubated patients. METHODS: This was a retrospective multicenter trial with 24 participating centers. Prehospital, emergency department, and hospital values were collected. Receiver operating characteristic curves were created and compared. Massive transfusion defined as >10 U of blood in 6 hours or death in 6 hours with at least 1 U of blood transfused. RESULTS: A total of 1,324 patients were enrolled. ETCO2 (area under the receiver operating characteristic curve [AUROC], 0.67; confidence interval [CI], 0.63-0.71) was better in predicting mortality than shock index (SI) (AUROC, 0.55; CI, 0.50-0.60) and systolic blood pressure (SBP) (AUROC, 0.58; CI, 0.53-0.62) (p < 0.0005). Prehospital lowest ETCO2 (AUROC, 0.69; CI, 0.64-0.75), SBP (AUROC, 0.75; CI, 0.70-0.81), and SI (AUROC, 0.74; CI, 0.68-0.79) were all predictive of MT. Analysis of patients with normotension demonstrated lowest prehospital ETCO2 (AUROC, 0.66; CI, 0.61-0.71), which was more predictive of mortality than SBP (AUROC, 0.52; CI, 0.47-0.58) or SI (AUROC, 0.56; CI, 0.50-0.62) (p < 0.001). Lowest prehospital ETCO2 (AUROC, 0.75; CI, 0.65-0.84), SBP (AUROC, 0.63; CI, 0.54-0.74), and SI (AUROC, 0.64; CI, 0.54-0.75) were predictive of MT in normotensive patients. ETCO2 cutoff for MT was 26 mm Hg. The positive predictive value was 16.1%, and negative predictive value was high at 98.1%. CONCLUSION: Prehospital ETCO2 is predictive of mortality and MT. ETCO2 outperformed traditional measures such as SBP and SI in the prediction of mortality. ETCO2 may outperform traditional measures in predicting need for transfusion in occult shock. LEVEL OF EVIDENCE: Diagnostic test, level III.

Hypobaric hypoxia exacerbates the neuroinflammatory response to traumatic brain injury.

OBJECTIVE: To determine the inflammatory effects of time-dependent exposure to the hypobaric environment of simulated aeromedical evacuation following traumatic brain injury (TBI). METHODS: Mice were subjected to a blunt TBI or sham injury. Righting reflex response (RRR) time was assessed as an indicator of neurologic recovery. Three or 24 h (Early and Delayed groups, respectively) after TBI, mice were exposed to hypobaric flight conditions (Fly) or ground-level control (No Fly) for 5 h. Arterial blood gas samples were obtained from all groups during simulated flight. Serum and cortical brain samples were analyzed for inflammatory cytokines after flight. Neuron specific enolase (NSE) was measured as a serum biomarker of TBI severity. RESULTS: TBI resulted in prolonged RRR time compared with sham injury. After TBI alone, serum levels of interleukin-6 (IL-6) and keratinocyte-derived chemokine (KC) were increased by 6 h post-injury. Simulated flight significantly reduced arterial oxygen saturation levels in the Fly group. Post-injury altitude exposure increased cerebral levels of IL-6 and macrophage inflammatory protein-1α (MIP-1α), as well as serum NSE in the Early but not Delayed Flight group compared to ground-level controls. CONCLUSIONS: The hypobaric environment of aeromedical evacuation results in significant hypoxia. Early, but not delayed, exposure to a hypobaric environment following TBI increases the neuroinflammatory response to injury and the severity of secondary brain injury. Optimization of the post-injury time to fly using serum cytokine and biomarker levels may reduce the potential secondary cerebral injury induced by aeromedical evacuation.

Hemostatic dressings reduce tourniquet time while maintaining hemorrhage control.

Tourniquet application has become first-line treatment for extremity hemorrhage on the battlefield and has seen increased use in the civilian arena. We hypothesized that an effective windlass tourniquet could be removed after application of a hemostatic dressing in a swine model of peripheral vascular injury. A tourniquet was placed proximally in 50 forelimb-injured swine after 30 seconds of hemorrhage with cessation of hemorrhage in all cases. Hemcon, ActCel, Quikclot, Celox, or standard gauze was then placed over the wound with direct pressure for three minutes. The tourniquet was then removed. Success was determined if no bleeding was identified. Standard gauze resulted in a 100 per cent failure rate with active bleeding present after each application. Celox was successful in maintaining hemostasis in 6 of 10 (60%) subjects. Quikclot succeeded in 80 per cent of subjects. ActCel maintained hemostasis in nine (90%) subjects, whereas HemCon was successful in all instances (100%). All four hemostatic dressings were superior to gauze in maintaining hemostasis after removal of an effective tourniquet. Use of hemostatic dressings in conjunction with a tourniquet may reduce tourniquet times and improve outcomes in peripheral vascular injury and warrants further study.

Impact of acute care surgery to departmental productivity.

BACKGROUND: The face of trauma surgery is rapidly evolving with a paradigm shift toward acute care surgery (ACS). The formal development of ACS has been viewed by some general surgeons as a threat to their practice. We sought to evaluate the impact of a new division of ACS to both departmental productivity and provider satisfaction at a University Level I Trauma Center. METHODS: Two-year retrospective analysis of annual work relative value unit (wRVU) productivity, operative volume, and FTEs before and after establishment of an ACS division at a University Level I trauma center. Provider satisfaction was measured using a 10-point scale. Analysis completed using Microsoft Excel with a p value less than 0.05 significant. RESULTS: The change to an ACS model resulted in a 94% increase in total wRVU production (78% evaluation and management, 122% operative; p<0.05) for ACS, whereas general surgery wRVU production increased 8% (-15% evaluation and management, 14% operative; p<0.05). Operative productivity was substantial after transition to ACS, with 129% and 44% increases (p<0.05) in operative and elective case load, respectively. Decline in overall general surgery operative volume was attributed to reduction in emergent cases. Establishment of the ACS model necessitated one additional FTE. Job satisfaction substantially improved with the ACS model while allowing general surgery a more focused practice. CONCLUSIONS: The ACS practice model significantly enhances provider productivity and job satisfaction when compared with trauma alone. Fears of a productivity impact to the nontrauma general surgeon were not realized.

Blunt traumatic occult pneumothorax: is observation safe?--results of a prospective, AAST multicenter study.

BACKGROUND: An occult pneumothorax (OPTX) is found incidentally in 2% to 10% of all blunt trauma patients. Indications for intervention remain controversial. We sought to determine which factors predicted failed observation in blunt trauma patients. METHODS: A prospective, observational, multicenter study was undertaken to identify patients with OPTX. Successfully observed patients and patients who failed observation were compared. Multivariate logistic regression was used to identify predictors of failure of observation. OPTX size was calculated by measuring the largest air collection along a line perpendicular from the chest wall to the lung or mediastinum. RESULTS: Sixteen trauma centers identified 588 OPTXs in 569 blunt trauma patients. One hundred twenty-one patients (21%) underwent immediate tube thoracostomy and 448 (79%) were observed. Twenty-seven patients (6%) failed observation and required tube thoracostomy for OPTX progression, respiratory distress, or subsequent hemothorax. Fourteen percent (10 of 73) failed observation during positive pressure ventilation. Hospital and intensive care unit lengths of stay, and ventilator days were longer in the failed observation group. OPTX progression and respiratory distress were significant predictors of failed observation. Most patient deaths were from traumatic brain injury. Fifteen percentage of patients in the failed observation group developed complications. No patient who failed observation developed a tension PTX, or experienced adverse events by delaying tube thoracostomy. CONCLUSION: Most blunt trauma patients with OPTX can be carefully monitored without tube thoracostomy; however, OPTX progression and respiratory distress are independently associated with observation failure.

Traumatic brain injury and aeromedical evacuation: when is the brain fit to fly?

BACKGROUND: To review the inflammatory sequelae of traumatic brain injury (TBI) and altitude exposure and discuss the potential impact of aeromedical evacuation (AE) on this process. METHODS: Literature review and expert opinion regarding the inflammatory effects of TBI and AE. RESULTS: Traumatic brain injury has been called the signature injury of the current military conflict. As a result of the increasing incidence of blast injury, TBI is responsible for significant mortality and enduring morbidity in injured soldiers. Common secondary insults resulting from post-traumatic cerebral inflammation are recognized to adversely impact outcome. AE utilizing Critical Care Air Transport Teams has become a standard of care practice following battlefield injury, to quickly and safely transport critically injured soldiers to more sophisticated echelons of care. Exposure to the hypobaric conditions of the AE process may impose an additional physiologic risk on the TBI patient as well as a "second hit" inflammatory stimulus. CONCLUSIONS: We review the known inflammatory effects of TBI and altitude exposure and propose that optimizing the post-traumatic inflammatory profile may assist in determining an ideal time to fly for head-injured soldiers.

Emergency airway placement by EMS providers: comparison between the King LT supralaryngeal airway and endotracheal intubation.

INTRODUCTION: The ever-present risk of mass casualties and disaster situations may result in airway management situations that overwhelm local emergency medical services (EMS) resources. Endotracheal intubation requires significant user education/training and carries the risk of malposition. Furthermore, personal protective equipment (PPE) required in hazardous environments may decrease dexterity and hinder timely airway placement. Alternative airway devices may be beneficial in these situations. OBJECTIVE: The objective of this study was to evaluate the time needed to place the King LT Supralaryngeal Airway compared to endotracheal intubation when performed by community EMS personnel with and without PPE. METHODS: Following training, 47 EMS personnel were timed placing both endotracheal tubes and the King LT supralaryngeal airway in a simulator mannikin. The study participants then repeated this exercise wearing PPE. RESULTS: The EMS personnel wearing PPE took significantly longer to place an endotracheal tube than they did without protective equipment (53.4 seconds and 39.5 seconds, p <0.002). The time to place the King LT was significantly faster than the placement of the endotracheal tube without protective equipment (18.4 seconds and 39.5 seconds, respectively, p <0.00003). There also were statistically significant differences between the time required to place the King LT and endotracheal tube in EMS personnel wearing protective equipment (19.7 seconds and 53.4 seconds, p <0.000007). CONCLUSIONS: The King LT Supralaryngeal Airway device may be advantageous in prehospital airway management situations involving multiple patients or hazardous environments. In this study, its insertion was faster than endotracheal intubation when performed by community EMS providers.

Air transport of patients with severe lung injury: development and utilization of the Acute Lung Rescue Team.

BACKGROUND: Critical Care Air Transport Teams (CCATTs) are an integral component of modern casualty care, allowing early transport of critically ill and injured patients. Aeromedical evacuation of patients with significant pulmonary impairment is sometimes beyond the scope of CCATT because of limitations of the transport ventilator and potential for further respiratory deterioration in flight. The Acute Lung Rescue Team (ALRT) was developed to facilitate transport of these patients out of the combat theater. METHODS: The United States TRANSCOM Regulation and Command/Control Evacuation System and the United States Army Institute of Surgical Research Joint Theater Trauma Registry databases were reviewed for all critical patients transported out of theater between November 2005 and March 2007. Patient demographics, diagnosis, and clinical history were abstracted and ALRT patients were compared with CCATT patients. RESULTS: The ALRT was activated for 11 patients during the study period. Five patients were transported as a result of these activations. Trauma-related diagnoses were responsible for 82% of these requests. ALRT missions comprised 0.6% of all critical patient movements out of the combat theater and 1% of ventilator transports. Average FIO2 was 0.92 +/- 0.11 for ALRT patients and 0.53 +/- 0.14 for CCATT patients (p = 0.005). ALRT patients required a mean positive end expiratory pressure of 19.0 cm H2O +/- 2.2 cm H2O compared with 6.5 cm H2O +/- 2.4 cm H2O in the CCATT group (p = 0.002). CONCLUSIONS: Lung injury in the combat theater severe enough to exceed the capability of CCATT transport is uncommon. Patients for whom ALRT was activated had significantly higher positive end expiratory pressure and FIO2 than those transported by CCATT. One-fourth of patients for whom ALRT was considered died before the team could be launched; transport may have been a futile consideration in these patients. Patients with even severe acute respiratory distress syndrome can be successfully transported by experienced, equipped specialty teams.

Surgical Simulation: Markers of Proficiency.

OBJECTIVE: Surgical simulation has become an integral component of surgical training. Simulation proficiency determination has been traditionally based upon time to completion of various simulated tasks. We aimed to determine objective markers of proficiency in surgical simulation by comparing novel assessments with conventional evaluations of technical skill. DESIGN: Categorical general surgery residents completed 10 laparoscopic cholecystectomy modules using a high-fidelity simulator. We recorded and analyzed simulation task times, as well as number of hand movements, instrument path length, instrument acceleration, and participant affective engagement during each simulation. Comparisons were made to Objective Structured Assessment of Technical Skill (OSATS) and Accreditation Council for Graduate Medical Education Milestones, as well as previous laparoscopic experience, duration of laparoscopic cholecystectomies performed by participants, and postgraduate year. Comparisons were also made to Fundamentals of Laparoscopic Surgery task times. Spearman's rho was utilized for comparisons, significance set at >0.50. SETTING: University of Missouri, Columbia, Missouri, an academic tertiary care facility. PARTICIPANTS: Fourteen categorical general surgery residents (postgraduate year 1-5) were prospectively enrolled. RESULTS: One hundred forty simulations were included. The number of hand movements and instrument path lengths strongly correlated with simulation task times (ρ 0.62-0.87, p < 0.0001), FLS task completion times (ρ 0.50-0.53, p < 0.0001), and prior real-world laparoscopic cholecystectomy experience (ρ -0.51 to -0.53, p < 0.0001). No significant correlations were identified between any of the studied markers with Accreditation Council for Graduate Medical Education Milestones, Objective Structured Assessment of Technical Skill evaluations, total previous laparoscopic experience, or postgraduate year level. Neither instrument acceleration nor participant engagement showed significant correlation with any of the conventional markers of real-world or simulation skill proficiency. CONCLUSIONS: Simulation proficiency, measured by instrument and hand motion, is more representative of simulation skill than simulation task time, instrument acceleration, or participant engagement.

Case Difficulty, Postgraduate Year, and Resident Surgeon Stress: Effects on Operative Times.

OBJECTIVE: We aimed to evaluate resident operative times in relation to postgraduate year (PGY), case difficulty and resident stress while performing a single surgical procedure. DESIGN: We prospectively examined operative times for 268 laparoscopic cholecystectomies, and analyzed relationships between PGY, case difficulty, and resident surgeon stress utilizing electrodermal activity. Each case operative times were divided into 3 separate time periods. Case Start and End times were recorded, as well as the time between the start of the operation and the time until the cystic structures were divided (Division). Case difficulty was determined by multiple trained observers with a high inter-rater concordance. SETTING: University of Missouri, a tertiary academic medical institution. PARTICIPANTS: All categorical general surgery residents at our institution. RESULTS: For each operative time period examined during laparoscopic cholecystectomy, operative time increased, with each incremental increase in difficulty resulting in approximately 130% longer times. Minimal differences in operative times were seen between PGY levels, except during the easiest cases (Start-End times: 38.5 ± 10.4 minutes vs 34.2 ± 10.8 minutes vs 28.9 ± 10.9 minutes, p 0.002). Resident stress poorly correlated with operative times regardless of case difficulty (Pearson coefficient range 0.0-0.22). CONCLUSIONS: Operative times are longer with increasing case difficulty. PGY level and resident surgeon stress appear to have minimal to no correlation with operative times, regardless of case difficulty.

Clearing the cervical spine in patients with distracting injuries: An AAST multi-institutional trial.

BACKGROUND: Single institution studies have shown that clinical examination of the cervical spine (c-spine) is sensitive for clearance of the c-spine in blunt trauma patients with distracting injuries. Despite an unclear definition, most trauma centers still adhere to the notion that distracting injuries adversely affect the sensitivity of c-spine clinical examination. A prospective AAST multi-institutional trial was performed to assess the sensitivity of clinical examination screening of the c-spine in awake and alert blunt trauma patients with distracting injuries. METHODS: During the 42-month study period, blunt trauma patients 18 years and older were prospectively evaluated with a standard c-spine examination protocol at 8 Level 1 trauma centers. Clinical examination was performed regardless of the presence of distracting injuries. Patients without complaints of neck pain, tenderness or pain on range of motion were considered to have a negative c-spine clinical examination. All patients with positive or negative c-spine clinical examination underwent computed tomography (CT) scan of the entire c-spine. Clinical examination findings were documented prior to the CT scan. RESULTS: During the study period, 2929 patients were entered. At least one distracting injury was diagnosed in 70% of the patients. A c-spine injury was found on CT scan in 7.6% of the patients. There was no difference in the rate of missed injury when comparing patients with a distracting injury to those without a distracting injury (10.4% vs. 12.6%, p = 0.601). Only one injury missed by clinical examination underwent surgical intervention and none had a neurological complication. CONCLUSIONS: Negative clinical examination may be sufficient to clear the cervical spine in awake and alert blunt trauma patients, even in the presence of a distracting injury. These findings suggest a potential source for improvement in resource utilization. LEVEL OF EVIDENCE: Therapeutic/care management, level IV.

En-route care in the air: snapshot of mechanical ventilation at 37,000 feet.

OBJECTIVE: En-route care necessitates the evacuation of seriously wounded service members requiring mechanical ventilation in aircraft where low light, noise, vibration, and barometric pressure changes create a unique clinical environment. Our goal was to evaluate ventilatory requirements, oxygenation, and oxygen use in flight and assess the feasibility of a computer interface in this austere environment. METHODS: A personal computer was integrated with the pulse oximeter and ventilator data port used in aeromedical evacuation from Iraq to Germany. Ventilator settings, inspired oxygen (FiO2), tidal volume (VT), respiratory rate (RR), minute ventilation (VE), monitored values, heart rate (HR), and oxygen saturation (SpO2), were recorded continuously. Oxygen use was determined using the equation ([FiO2 - 21]/79) x (MVE). Additional data were obtained through the United States Air Force (USAF) Transcom Regulation and Command/Control Evacuation System (TRAC2ES) and the United States Army Institute of Surgical Research Joint Theater Trauma Registry databases. RESULTS: During a 4 month time frame 117 hours of continuous recording was accomplished in 22 patients. Mean age was 27 +/- 9.83 and injury severity score military was 31.75 +/- 20.63 (range, 9-75). All patients survived transport. Mean values for ventilator settings were FiO2 (24-100%) of 49% +/- 13%, positive end-expiratory pressure of 6 +/- 2.5 (range, 0-17 cm H2O), RR of 15 +/- 2.4 (range, 10-22 breaths/min), and VT of 611 +/- 75 (range, 390-700 mL). Delivered VT in mililiter per kilogram was 6.9 +/- 1.30 and VE was 9.1 L/min +/- 1.4 L/min. Oxygen requirements for desired FiO2 and VE resulted in a mean oxygen usage of 3.24 L/min +/- 1.87 L/min (range, 1.6-10.2 L/min). There were 32 changes to FiO2, 18 changes to PEEP, 26 changes to RR, and 20 changes to VT during flight. Five patients under-went no recorded changes in flight. Three desaturation events (<90%) were recorded lasting 35, 115, and 280 seconds. Recorded ventilatory changes averaged less than 1 (0.82) per hour of recorded flight with FiO2 being the most common. CONCLUSIONS: A computer interface is feasible in the austere aeromedical environment. Implications to military operations and civilian homeland defense include understanding casualty oxygen requirements for resource planning in support of aeromedical evacuation. Portable oxygen generation systems may be able to provide adequate oxygen flow for transport, reducing the need for compressed gas. Future studies of oxygen conservation systems including closed loop control of FiO2 are warranted.

Manual suturing quality at acceleration levels equivalent to spaceflight and a lunar base.

INTRODUCTION: Cutaneous wounds, either from injuries or as a result of surgical incisions, are a likely possibility that future space medicine specialists will need to address. While there has been some prior study of manual suturing in microgravity (0 G), there has been no study of manual suturing in reduced gravity consistent with that of the Moon. METHODS: Six separate operators with varying degrees of surgical experience (four trained surgeons, and two non-surgeons) attempted to manually suture wound phantoms during the reduced gravity phases of parabolic flight simulating either 0 G or lunar gravity (0.16 G). Each operator subjectively evaluated the difficulty and relative speed in performing the same task in different environments, serving as their own internal control. There were 20-s periods of 1 G that were carefully timed for each surgeon to compare to the approximately 20 s available for each parabola of either 0 G or 0.16 G. RESULTS: Six periods of 1 G were used as controls to perform manual suturing of the phantoms. There were 51 parabolas of 0 G and 67 parabolas of 0.16 G performed by the six operators. As judged subjectively by the operators themselves and by group inspection of the sutured phantoms, there was no qualitative difference in the adequacy of wound closure as judged by suture placement accuracy and wound coaptation. There was consensus, though, that suturing in microgravity was significantly slower, as has been noted in more complex surgical studies. DISCUSSION: The technical aspects of wound management during exploration-class missions in prolonged microgravity or lunar missions with reduced gravity (0.16 G) will likely not present challenges beyond those faced in addressing the tremendous logistical and training obstacles to providing experienced and equipped surgeons on-board such a mission.