Bradford G. Scott

Hypotensive Resuscitation Strategy Reduces Transfusion Requirements and Severe Postoperative Coagulopathy in Trauma Patients With Hemorrhagic Shock: Preliminary Results of a Randomized Controlled Trial

BACKGROUND Trauma is a leading cause of death worldwide and is thus a major public health concern. Previous studies have shown that limiting the amount of fluids given by following a strategy of permissive hypotension during the initial resuscitation period may improve trauma outcomes. This study examines the clinical outcomes from the first 90 patients enrolled in a prospective, randomized controlled trial of hypotensive resuscitation, with the primary aim of assessing the effects of a limited transfusion and intravenous (IV) fluid strategy on 30-day morbidity and mortality. METHODS Patients in hemorrhagic shock who required emergent surgery were randomized to one of the two arms of the study for intraoperative resuscitation. Those in the experimental (low mean arterial pressure [LMAP]) arm were managed with a hypotensive resuscitation strategy in which the target mean arterial pressure (MAP) was 50 mm Hg. Those in the control (high MAP [HMAP]) arm were managed with standard fluid resuscitation to a target MAP of 65 mm Hg. Patients were followed up for 30 days. Intraoperative fluid requirements, mortality, postoperative complications, and other clinical data were prospectively gathered and analyzed. RESULTS Patients in the LMAP group received a significantly less blood products and total i.v. fluids during intraoperative resuscitation than those in the HMAP group. They had significantly lower mortality in the early postoperative period and a nonsignificant trend for lower mortality at 30 days. Patients in the LMAP group were significantly less likely to develop immediate postoperative coagulopathy and less likely to die from postoperatively bleeding associated with coagulopathy. Among those who developed coagulopathy in both groups, patients in the LMAP group had significantly lower international normalized ratio than those in the HMAP group, indicating a less severe coagulopathy. CONCLUSIONS Hypotensive resuscitation is a safe strategy for use in the trauma population and results in a significant reduction in blood product transfusions and overall IV fluid administration. Specifically, resuscitating patients with the intent of maintaining a target minimum MAP of 50 mm Hg, rather than 65 mm Hg, significantly decreases postoperative coagulopathy and lowers the risk of early postoperative death and coagulopathy. These preliminary results provide convincing evidence that support the continued investigation and use of hypotensive resuscitation in the trauma setting.

Minimizing dilutional coagulopathy in exsanguinating hemorrhage: a computer simulation.

BACKGROUND Current massive transfusion guidelines are derived from washout equations that may not apply to bleeding trauma patients. Our aim was to analyze these guidelines using a computer simulation. METHODS A combined hemodilution and hemodynamic model of an exsanguinating patient was developed to calculate the changes in prothrombin time (PT), fibrinogen, and platelets with bleeding. The model was calibrated to data from 44 patients. Time intervals to subhemostatic values of each coagulation test were calculated for a range of replacement options. RESULTS Prolongation of PT is the sentinel event of dilutional coagulopathy and occurs early in the operation. The key to preventing coagulopathy is plasma infusion before PT becomes subhemostatic. The optimal replacement ratios were 2:3 for plasma and 8:10 for platelets. Concurrent transfusion of plasma with blood is another effective strategy for minimizing coagulopathy. CONCLUSION Existing protocols underestimate the dilution of clotting factors in severely bleeding patients. The model presents an innovative approach to optimizing component replacement in exsanguinating hemorrhage.

How does casualty load affect trauma care in urban bombing incidents? A quantitative analysis

BACKGROUND The aim of this modeling study was to examine how casualty load affects the level of trauma care in multiple casualty incidents and to define the surge capacity of the hospital trauma assets. METHODS The disaster plan of a U.S. Level I trauma center was translated into a computer model and challenged with simulated casualties based on 223 patients from 22 bombing incidents treated at an Israeli hospital. The model assigns providers and facilities to casualties and computes the level of care for each critical casualty from six variables that reflect the composition of the trauma team and access to facilities. RESULTS The model predicts a sigmoid-shaped relationship between casualty load and the level of care, with the upper flat portion of the curve corresponding to the surge capacity of the trauma assets of the hospital. This capacity is 4.6 critical patients per hour using immediately available assets. A fully deployed disaster plan shifts the curve to the right, increasing the surge capacity to 7.1. Overtriage rates of 50% and 75% shift the curve to the left, decreasing the surge capacity to 3.8 and 2.7, respectively. CONCLUSION This model defines the quantitative relationship between an increasing casualty load and gradual degradation of the level of trauma care in multiple casualty incidents, and defines the surge capacity of the hospital trauma assets as a rate of casualty arrival rather than a number of beds. The study demonstrates the value of dynamic computer modeling as an important tool in disaster planning.

TEG-guided resuscitation is superior to standardized MTP resuscitation in massively transfused penetrating trauma patients.

BACKGROUND For nearly a decade, our center performed thromboelastograms (TEGs) to analyze coagulation profiles, allowing rapid data-driven blood component therapy. After consensus recommendations for massive transfusion protocols (MTPs), we implemented an MTP in October 2009 with 1:1:1 ratio of blood (red blood cells [RBC]), plasma (fresh-frozen plasma [FFP]), and platelets. We hypothesized that TEG-directed resuscitation is equivalent to MTP resuscitation. METHODS All patients receiving 6 units (U) or more of RBC in the first 24 hours for 21 months before and after MTP initiation in an urban Level I trauma center were examined. Demographics, mechanism of injury (MOI), Injury Severity Score (ISS), 24-hour volume of RBC, FFP, platelets, crystalloid, and 30-day mortality were compared, excluding patients with traumatic brain injuries. Variables were analyzed using Student’s t-test and &khgr;2 or Fisher’s exact test. RESULTS For the preMTP group, there were 165 patients. In the MTP group, there were 124 patients. There were no significant differences in ISS, age, or sex. PreMTP patients with 6U or more RBC had significantly more penetrating MOI (p = 0.017), whereas preMTP patients with 10U or more RBC had similar MOIs. All patients received less crystalloid after MTP adoption (p < 0.001). There was no difference in volume of blood products or mortality in patients receiving 6U or more RBC. Blunt trauma MTP patients who received 10U or more RBC received more FFP (p = 0.02), with no change in mortality. Penetrating trauma patients who received 10U or more RBC received a similar volume of FFP; however, mortality increased from 54.1% for MTP versus 33.3% preMTP (p = 0.04). CONCLUSION TEG-directed resuscitation is equivalent to standardized MTP for patients receiving 6U or more RBC and for blunt MOI patients receiving 10U or more RBC. MTP therapy worsened mortality in penetrating MOI patients receiving 10U or more RBC, indicating a continued need for TEG-directed therapy. A 1:1:1 strategy may not be adequate in all patients. LEVEL OF EVIDENCE Therapeutic study, level IV.

Education of the Modern Surgical Resident: Novel Approaches to Learning in the Era of the 80-Hour Workweek

IntroductionImplementation of the 80-hour work week has resulted in limitations on the hours available for resident education, creating a need for innovative approaches to teach surgical residents successfully. Herein we report the methods and results of an innovative didactic learning program at a large academic surgerical residency program.MethodsBetween 2004 and 2005, based on known principles of adult education and innovative learning techniques, a didactic learning program was instituted in a major academic surgery program. The course work consisted of a structured reading program using Schwartz’s Textbook of Surgery, with weekly testing and problem-based learning (PBL) groups led by surgical faculty. The residents’ progress was assessed by American Board of Surgery In-Training Examination (ABSITE) training scores before and after program implementation. A resident survey was also conduced to assess residents’ attitudes toward the new program. Results were reported as a mean, and categoric variables were compared using a paired Student’s t-test.ResultsDuring the academic year of the structured reading program, the mean ABSITE score improved by 10% (P = 0.02) from the previous year. The postgraduate year 4 class had the largest change, with a score increase of 17% over the previous year’s performance (P = 0.02). Survey results demonstrated that 64% of the responders agreed that the small-group PBL was preferable for achieving educational goals. Furthermore, 89% of residents responded that the PBL groups improved interaction between residents and faculty members.ConclusionsAn innovative formal learning program based on a major surgical textbook with weekly testing and small group sessions can significantly improve surgical training in the modern era of work-hour restrictions. Furthermore, surgical trainees find this format to be innovative and useful for improving didactic teaching.

Impact of morbid obesity on outcome of laparoscopic splenectomy

BackgroundBecause of the obesity epidemic, surgeons are operating on morbidly obese patients in increasing numbers. The aim of this study was to evaluate the impact of morbid obesity on the outcome of laparoscopic splenectomy.MethodsThe study group consisted of 120 consecutive patients who underwent laparoscopic splenectomy for benign and malignant disease from March 1996 to May 2005. These patients were retrospectively divided into three groups. Group 1 had a body mass index (BMI) < 30. Group 2 patients had a BMI ≥ 30 and < 40 and were considered obese. Group 3 had a BMI ≥ 40 and were considered morbidly obese. Data including surgical approach (laparoscopic vs. hand-assisted), operative time, conversion rate, estimated blood loss, splenic weight, length of stay, time to tolerate a diet, pathologic diagnosis, complications, and mortality were recorded.ResultsComplete data were available for evaluation of 112 patients of whom 73 (65%) had a BMI < 30, 32 (29%) had a BMI ≥ 30 and < 40, and 7 (6%) had a BMI ≥ 40. The most frequent indication for splenectomy in all three groups was idiopathic thrombocytopenic purpura (ITP). The operative times were significantly higher in patients with a BMI > 40. Conversion rates were also higher in this group, although this did not reach statistical significance. Patients with a BMI > 30 experienced similar complication rates when compared with patients with a BMI < 30. Only when patients had a BMI > 40 did they experience more complications.ConclusionsLaparoscopic splenectomy was performed safely in obese patients (BMI > 30) with similar results to those of nonobese patients. Only in morbidly obese patients (BMI > 40) do outcomes and complications appear to be affected. Obesity should not be a contraindication to laparoscopic splenectomy.

Randomized, controlled trial comparing the effects of anesthesia with propofol, isoflurane, desflurane and sevoflurane on pain after laparoscopic cholecystectomy

BACKGROUND Pain is the primary complaint and the main reason for prolonged recovery after laparoscopic cholecystectomy. The authors hypothesized that patients undergoing laparoscopic cholecystectomy will have less pain four hours after surgery when receiving maintenance of anesthesia with propofol when compared to isoflurane, desflurane, or sevoflurane. METHODS In this prospective, randomized trial, 80 patients scheduled for laparoscopic cholecystectomy were assigned to propofol, isoflurane, desflurane, or sevoflurane for the maintenance of anesthesia. Our primary outcome was pain measured on the numeric analog scale four hours after surgery. We also recorded intraoperative use of opioids as well as analgesic consumption during the first 24h after surgery. RESULTS There was no statistically significant difference in pain scores four hours after surgery (p=0.72). There were also no statistically significant differences in pain scores between treatment groups during the 24h after surgery (p=0.45). Intraoperative use of fentanyl and morphine did not vary significantly among the groups (p=0.21 and 0.24, respectively). There were no differences in total morphine and hydrocodone/APAP use during the first 24h (p=0.61 and 0.53, respectively). CONCLUSION Patients receiving maintenance of general anesthesia with propofol do not have less pain after laparoscopic cholecystectomy when compared to isoflurane, desflurane, or sevoflurane.

Intraoperative hypotensive resuscitation for patients undergoing laparotomy or thoracotomy for trauma: Early termination of a randomized prospective clinical trial.

Background Hemorrhagic shock is responsible for one third of trauma related deaths. We hypothesized that intraoperative hypotensive resuscitation would improve survival for patients undergoing operative control of hemorrhage following penetrating trauma. Methods Between July 1, 2007, and March 28, 2013, penetrating trauma patients aged 14 years to 45 years with a systolic blood pressure of 90 mm Hg or lower requiring laparotomy or thoracotomy for control of hemorrhage were randomized 1:1 based on a target minimum mean arterial pressure (MAP) of 50 mm Hg (experimental arm, LMAP) or 65 mm Hg (control arm, HMAP). Patients were followed up 30 days postoperatively. The primary outcome of mortality; secondary outcomes including stroke, myocardial infarction, renal failure, coagulopathy, and infection; and other clinical data were analyzed between study arms using univariate and Kaplan-Meier analyses. Results The trial enrolled 168 patients (86 LMAP, 82 HMAP patients) before early termination, in part because of clinical equipoise and futility. Injuries resulted from gunshot wounds (76%) and stab wounds (24%); 90% of the patients were male, and the median age was 31 years. Baseline vitals, laboratory results, and injury severity were similar between groups. Intraoperative MAP was 65.5 ± 11.6 mm Hg in the LMAP group and 69.1 ± 13.8 mm Hg in the HMAP group (p = 0.07). No significant survival advantage existed for the LMAP group at 30 days (p = 0.48) or 24 hours (p = 0.27). Secondary outcomes were similar for the LMAP and HMAP groups: acute myocardial infarction (1% vs. 2%), stroke (0% vs. 3%), any renal failure (15% vs. 12%), coagulopathy (28% vs. 29%), and infection (59% vs. 58%) (p > 0.05 for all). Acute renal injury occurred less often in the LMAP than in HMAP group (13% vs. 30%, p = 0.01). Conclusion This study was unable to demonstrate that hypotensive resuscitation at a target MAP of 50 mm Hg could significantly improve 30-day mortality. Further study is necessary to fully realize the benefits of hypotensive resuscitation. LEVEL OF EVIDENCE Therapeutic study, level II.

Impact of a novel education curriculum on surgical training within an academic training program.

BACKGROUND The training of the 21st century surgeon has become increasingly complex with the Accreditation Council for Graduate Medical Education (ACGME) core competency requirements and work-hour restrictions. Herein we report the two-year results of a novel problem-based learning education module at a large academic surgery program. METHODS All data were prospectively collected from 2004 to 2006 on all categorical residents in the department of surgery (n = 42). Analysis was performed to identify any correlation between class attendance and American Board of Surgery In-Service Training Exam (ABSITE) score performance (percentile change). All data were reported as a mean with a standard error of the mean. Categorical variables were analyzed using a paired Students t-test. A bivariate correlation was calculated using Spearmans rho correlation. RESULTS When comparing the 2004 scores (pre-program) to 2006 scores, there was significant score improvement (P <or= 0.05), with a mean increase of 8% on ABSITE scores across all classes. Furthermore, from 2005 to 2006, the mean ABSITE score was stable for all classes with no significant decrease (P = 0.34). Of note, the PGY-4 class had a significant improvement of 15% (P <or= 0.05). Bivariate analysis demonstrated a slight trend toward a significant relationship between class attendance and ABSITE score improvement, however, this did not reach statistical significance (P = 0.15). CONCLUSION A problem-based learning (PBL) based education program can successfully meet the educational goals of a surgical training program. Furthermore, this program has demonstrated consistent results with maintenance of score improvements through a two-year period.

Emergency endovascular management of penetrating gunshot injuries to the arteries in the face and neck: a case series and review of the literature

Introduction Penetrating gunshot injuries (GSI) to supra-aortic arteries that cause life-threatening blood loss or major neurologic deficits are increasingly managed using modern endovascular treatment (EVT). We report our experience with EVT of acute GSIs and review the existing literature. Methods Emergency EVT was performed in nine of 10 patients (7 men, age 17–50 years) with acute GSIs to supra-aortic arteries requiring acute management. One patient presented with acute and delayed injuries and underwent EVT 4 weeks after initial admission. Patient selection was based on clinical presentation and radiographic findings from a cohort of 55 patients with GSIs to the face, neck or head between February 2009 and March 2012. Results EVT was successfully performed in all patients. Two transections of the vertebral arteries were embolized with coils and/or liquid embolic agent (acrylic glue). Eight penetrated external carotid artery branches were occluded with liquid embolic agents (acrylic glue or Onyx) or particles. One severe dissection of the internal carotid artery with a subsequent thromboembolic event was treated with stenting. All except one patient survived with minor or no residual deficits. Conclusions Emergency management of GSI injuries to the head and neck may involve all aspects of current EVT. Understanding endovascular techniques and being able to make rapid and appropriate treatment decisions in the setting of acute GSI to the face and neck can be a life-saving measure and greatly benefits the patients outcome.