Risk Factors and Outcomes of Late Posttraumatic Seizures in Combat-Related Traumatic Brain Injury.

INTRODUCTION: Post-traumatic seizures (PTSs) contribute to morbidity after traumatic brain injury (TBI). Early PTS are rare in combat casualties sustaining TBI, but the prevalence of late PTS is poorly described. We sought to define the prevalence and risk factors of late PTS in combat casualties with computed tomography evidence of TBI. METHODS: From 2010 to 2015, 687 combat casualties were transferred to a military treatment facility and included in the Department of Defense Trauma Registry. 71 patients with radiographic evidence of TBI were analyzed. Data collection included demographics, injury characteristics, interventions, medications, and outcomes. RESULTS: Of the 71 patients with evidence of TBI, 66 patients survived hospitalization and were followed. No patients had early PTS, and most received antiepileptic drugs (AEDs) for prophylaxis. At a median follow-up of 7.4 y, late PTS occurred in 25.8% of patients. Patients with late PTS were more severely injured (median Injury severity score 30 versus 24, P = 0.005) and required more blood products (18 units versus 2, P = 0.045). Patients with late PTS were more likely to have had a penetrating TBI (76.5% versus 38.8%, P = 0.01), multiple types of intracranial hemorrhage (94.1% versus 63.3%, P = 0.02), and cranial decompression (76.5% versus 28.6%, P = 0.001). Six-month Glasgow outcome scores were worse (3.5 versus 4.1 P = 0.001) in the late PTS population. No significant relationship was observed between administration of AEDs for early PTS prophylaxis and late PTS. CONCLUSIONS: Combat casualties with TBI suffering late PTS are more severely injured and require more blood products. Penetrating TBI, intracranial hemorrhage, and need for cranial decompression are correlated with late PTS, and associated with worse Glasgow Outcome Score. The administration of prophylactic AEDs for early PTS was not associated with a difference in rates of late PTS.

NSQIP Based Predictors of False Negative and Indeterminate Ultrasounds in Adults With Appendicitis.

BACKGROUND: It has been well established that ultrasound (US) is the initial screening tool for children with suspected acute appendicitis. However, computed tomography (CT) has become the standard screening modality for adults presenting with abdominal pain. A recent review of National Surgical Quality Improvement Program (NSQIP) data revealed US is being utilized as a screening modality in adults. We aimed to assess the diagnostic performance of US in evaluating adults with acute appendicitis. STUDY DESIGN: The American College of Surgeons NSQIP and NSQIP Procedure Targeted Data Files were accessed and examined for all patients in 2016 and 2017 who received an US and underwent an appendectomy. The US results were then correlated to the pathology in order to determine the diagnostic performance. Additionally, we identified predictors for indeterminate and false negative US results. RESULTS: Our study included 3607 appendectomy patients of which 1135 (30%) had an indeterminate US, 683 (18%) had an US not consistent with appendicitis, and 1789 (49%) had an US consistent with appendicitis. Sensitivity and Specificity were 74.3% and 53.0%, respectively. Positive Predictive Value (PPV) and Negative Predictive Value (NPV) were 95.9% and 12.2%, respectively. On regression analysis, clinically relevant predictors for false negative and indeterminate studies included age, sex, and BMI. CONCLUSIONS: Ultrasound is an effective initial imaging modality for acute appendicitis in the adult population. Females, age >30 y, and elevated BMI were more likely to have indeterminate or false negative results. These patients may benefit from CT as their initial screening test.

Beyond the Expected: Evaluating Preoperative Predictors of a Difficult Cholecystectomy Aboard the USNS Comfort.

Mini abstract Typical preoperative markers of a difficult laparoscopic cholecystectomy did not apply during the US Naval ShipComfort Deployment in 2019. This prospective study reveals the importance of preparedness for short-term surgical missions, the impact of health care disparities on the severity of disease, and the need for deliberate and thoughtful engagement with host-nation partners.

Use of Levetiracetam for Post-Traumatic Seizure Prophylaxis in Combat-Related Traumatic Brain Injury.

INTRODUCTION: Post-traumatic seizure (PTS) prophylaxis is recommended in patients with traumatic brain injury (TBI) at high risk for PTSs, but consensus on the optimal pharmacologic therapy has not yet been established. Levetiracetam is frequently used for seizure prophylaxis in combat-related TBI, but its efficacy and safety in this patient population has not yet been described. METHODS: A retrospective cohort of 687 consecutive casualties transferred to the CONUS from October 2010 to December 2015 was analyzed. Seventy-one patients with combat-related injuries and radiographic evidence of skull fractures or intracranial hemorrhage were included. Data collection included demographics and injury characteristics including initial Glasgow Coma Scale, computed tomography findings, interventions, and 6-month Glasgow Outcome Score. RESULTS: All patients in this cohort were male, with an average age of 25 (median 24; Interquartile range (IQR) 4.5) and an average Injury Severity Score of 28 (median 27; IQR 15). The most common mechanism of injury was explosive blast (76%). Penetrating TBI was common (51%). Most patients (88.7%) were administered seizure prophylaxis. Of these, the majority (61/63) received levetiracetam, and the additional two were administered phenytoin. The remaining 11.3% of patients were deemed not to require seizure prophylaxis. The incidence of seizures while on prophylaxis was low (2.8%) and occurred in patients who suffered transcranial gunshot wounds and ultimately died. No serious adverse effects were attributed to levetiracetam. CONCLUSIONS: Levetiracetam appears to be a safe and effective medication for PTS prophylaxis in combat casualties. The rate of PTSs in combat-related TBI on appropriate prophylaxis is low.

Simple signage and targeted education can lead to process improvement in acute appendicitis care.

INTRODUCTION: An institution-wide protocol for uncomplicated acute appendicitis was created to improve compliance with best practices between the emergency department (ED), radiology and surgery. Awareness of the protocol was spread with the publication of a smartphone application and communication to clinical leadership. On interim review of quality metrics, poor protocol adherence in diagnostic imaging and antimicrobial stewardship was observed. The authors hypothesised that two further simple interventions would result in more efficient radiographic diagnosis and antimicrobial administration. MATERIALS AND METHODS: Surgery residents received targeted in-person education on the appropriate antibiotic choices and diagnostic imaging in the protocol. Signs were placed in the emergency and radiology work areas, immediately adjacent to provider workstations highlighting the preferred imaging for patients with suspected appendicitis and the preferred antibiotic choices for those with proven appendicitis. Protocol adherence was compared before and after each intervention. RESULTS: Targeted education was associated with improved antibiotic stewardship within the surgical department from 30% to 91% protocol adherence before/after intervention (p<0.005). Visible signs in the ED were associated with expedited antimicrobial administration from 50% to 90% of patients receiving antibiotics in the ED prior to being brought to the operating room before/after intervention (p<0.005). Diagnostic imaging after the placement of signs showed improved protocol adherence from 35% to 75% (p<0.005). CONCLUSION: This study demonstrates that smartphone-based applications and communication among clinical leadership achieved suboptimal adherence to an institutional protocol. Targeted in-person education reinforcement and visible signage immediately adjacent to provider workstations were associated with significantly increased adherence. This type of initiative can be used in other aspects of acute care general surgery to further improve quality of care and hospital efficiency.

Development, refinement, and characterization of a nonhuman primate critical care environment.

BACKGROUND: Systemic inflammatory response remains a poorly understood cause of morbidity and mortality after traumatic injury. Recent nonhuman primate (NHP) trauma models have been used to characterize the systemic response to trauma, but none have incorporated a critical care phase without the use of general anesthesia. We describe the development of a prolonged critical care environment with sedation and ventilation support, and also report corresponding NHP biologic and inflammatory markers. METHODS: Eight adult male rhesus macaques underwent ventilation with sedation for 48-96 hours in a critical care setting. Three of these NHPs underwent "sham" procedures as part of trauma control model development. Blood counts, chemistries, coagulation studies, and cytokines/chemokines were collected throughout the study, and histopathologic analysis was conducted at necropsy. RESULTS: Eight NHPs were intentionally survived and extubated. Three NHPs were euthanized at 72-96 hours without extubation. Transaminitis occurred over the duration of ventilation, but renal function, acid-base status, and hematologic profile remained stable. Chemokine and cytokine analysis were notable for baseline fold-change for Il-6 and Il-1ra (9.7 and 42.7, respectively) that subsequently downtrended throughout the experiment unless clinical respiratory compromise was observed. CONCLUSIONS: A NHP critical care environment with ventilation support is feasible but requires robust resources. The inflammatory profile of NHPs is not profoundly altered by sedation and mechanical ventilation. NHPs are susceptible to the pulmonary effects of short-term ventilation and demonstrate a similar bioprofile response to ventilator-induced pulmonary pathology. This work has implications for further development of a prolonged care NHP model.

Conformations of the glycine tripeptide analog Ac-Gly-Gly-NHMe: a computational study including aqueous solvation effects.

A computational study of the conformational preferences of the glycine tripeptide analog, Ac-Gly-Gly-NHMe, has been carried out. The molecule is considered in isolation as well as with a continuum model of aqueous solvation. In the absence of solvent, several low-energy conformers are found that exhibit turnlike structures including type I and type II ß turns. Upon consideration of aqueous solvation, two conformers, corresponding to the type I and II turn structures are found to be significantly lower in energy than all others. Results from ab initio molecular orbital theory calculations at MP2/aug-cc-pVTZ//MP2/6-311+G(d,p) are compared with those from density functional theory with B3LYP, ωB97X-D, B97-D, and M06-2X as well as several empirical force fields.

A Decade of Surgery Aboard the U.S. Naval Ship COMFORT (T-AH 20).

INTRODUCTION: The U.S. Naval Ship COMFORT has performed six humanitarian assistance and disaster relief mission since 2007. This paper describes the surgical volume per surgical specialty for five missions spanning 19 countries. MATERIALS AND METHODS: Raw surgical case logs were analyzed for total case volume, total operating days, unanticipated return to operating room, and percentage of pediatric cases (<18 years old) for each country visited. RESULTS: Total surgical volume for the five missions was 5,142. The countries most frequently visited were Columbia and Haiti with seven and five visits, respectively. General surgery, ophthalmology, and plastic surgery have had consistent volume over time. Orthopedic surgery volume has steadily decreased with the exception of the 2018 mission. CONCLUSION: As volume in military treatment facilities declines, alternative sources of surgical volume for military surgeons are being examined. This paper highlights the historical volume which can inform future personnel planning requirements of U.S. Naval Ship COMFORT missions. With the exception of orthopedic surgery, surgical volume has remained consistent over the last decade. For future best practice, historical case data should be used to determine staffing needs on hospital ships and case logs and operating procedures and follow-up protocols should be standardized.

Characterization of the cortisol response to traumatic hemorrhage and intra-abdominal contamination models in Cynomologus Macaques.

INTRODUCTION: Trauma, hemorrhage, and peritonitis have widely varying impacts on endocrine response in the injured patient. We sought to examine cortisol response in established non-human primate models of traumatic hemorrhage and intra-abdominal contamination. METHODS: Cynomologus Macaques were separated into two experimental groups, the polytrauma and hemorrhage model, involving a laparoscopic liver resection with uncontrolled hemorrhage, cecal perforation, and soft tissue excision; and the traumatic hemorrhage model, involving only liver resection and uncontrolled hemorrhage. Cortisol levels were measured pre-operatively, at the time of injury, and at regular intervals until post-operative day 1. RESULTS: Cortisol levels increased 600% from the pre-operative value in the polytrauma and hemorrhage model, with minimal changes (20%) in the hemorrhage only model. CONCLUSION: Cortisol levels increase dramatically in response to polytrauma and intra-abdominal contamination as compared to hemorrhage only. The lack of response in the hemorrhage only group may be due to relative adrenal insufficiency caused by the shock state or lack of enticing stimuli from fecal peritonitis.

Characterization of serum levels of testosterone and corticosterone in a blast and amputation rat model of heterotopic ossification.

INTRODUCTION: Endocrine dysregulation's role in heterotopic ossification (HO) remains unexplored. We sought to examine corticosterone and testosterone in established rat models of ectopic bone formation, and correlate to HO formation with CT analysis. METHODS: Fifteen rats were placed into three groups of traumatic injury patterns: Blast and injury (120 kPa blast, femoral fracture and quadriceps crush), injury only, and blast only. Serum corticosterone and testosterone levels were drawn until post-operative day 40. HO was analyzed using CT. RESULTS: Corticosterone levels peaked in the blast and injury group in the shortest time post injury, followed by injury only and blast only groups. Testosterone levels reached nadir in similar fashion. Volume of HO was highest in the blast and injury group, followed by the injury only group. CONCLUSION: Corticosterone and testosterone's contribution to HO formation requires further characterization, but this study suggests that high peaks in corticosterone and a low nadir in testosterone are associated with higher volumes of HO.