Jacob J. Glaser

Continuing promise 2009—assessment of a recent pediatric surgical humanitarian mission

PURPOSE Surgical organizations have begun to focus their efforts on providing humanitarian assistance in international communities. Most surgeons do not have previous international experience and lack an understanding of what is expected and what care they can provide. The unknown factors include case types, patient volume, postoperative care, and equipment. This abstract presents humanitarian assistance mission and highlights the importance of preparation, host nation involvement, and understanding the local politics of each country. METHODS In April to July 2009, the USNS (United States Naval Ship) Comfort deployed to provide humanitarian assistance to 7 countries through Central and South America. Data collected included numbers and types of procedures, rate of rejection of patients for operation, patient age, American Society of Anesthesiology (ASA) score, and length of procedure. RESULTS These data represent the total mission of Continuing Promise 2009 including a total of 1137 surgical procedures of which 340 were pediatric (<18 years old). The average number of pediatric cases for each country in 7 days was 48.3 ± 21.4, with a range of 24 to 84. The average age was 7.5 years (range, 1 month to 18 years). In partnership with host physicians, preoperative screening occurred over 2 to 3 days for every 7 operative days. We maintained a low threshold for rejection (rate of 43%; range, 21%-62%) and average ASA score of 1.3. Including all pediatric subspecialties, the most frequent procedures were inguinal (23%) and umbilical (14%) hernias. Although these were the most frequent procedure, the range and variety of cases varied widely. We had a very low early complication rate (1.2%), including 3 wound infections and 1 early hernia recurrence. CONCLUSIONS Our data represent the largest collection to date on the pediatric surgical care of children in a humanitarian effort. Our experience can be used to identify the most likely types of cases in South and Central America and as a model for the safe and efficient treatment of children in a developing country.

Ratio-driven resuscitation predicts early fascial closure in the combat wounded.

BACKGROUND Operation Iraqi Freedom and Operation Enduring Freedom have seen the highest rates of combat casualties since Vietnam. These casualties often require massive transfusion (MT) and immediate surgical attention to control hemorrhage. Clinical practice guidelines dictate ratio-driven resuscitation (RDR) for patients requiring MT. With the transition from crystalloid to blood product resuscitation, we have seen fewer open abdomens in combat casualties. We sought to determine the effect RDR has on achieving early definitive abdominal fascial closure in combat casualties undergoing exploratory laparotomy. METHODS Records of 1,977 combat casualties admitted to a single US military hospital from April 2003 to December 2011 were reviewed. Patients receiving an MT and laparotomy in theater constituted the study cohort. The cohort was divided into RDR, defined as a ratio of 0.8-U to 1.2-U packed red blood cells to 1-U fresh frozen plasma, and No-RDR groups. Age, injury patterns, mechanism of injury, injury severity, blood products, number of laparotomies, and days to fascial closure were collected. Assessed outcomes were number of days (early ⩽ 2 days) and number of laparotomies to achieve fascial closure. RESULTS The mean age of the study cohort (n = 172) was 24.0 years, and mean Injury Severity Score (ISS) was 24.8. Improvised explosive device blast was the most common mechanism of injury (74.4%). The cohort was divided into RDR patients (n = 73) and no RDR (n = 99). There was no difference in mean age, mean ISS, or rate of nontherapeutic exploratory laparotomies between the groups. RDR patients had a significantly lower abdominal injury rate (34.2% vs. 72.7%, p < 0.01), had fewer laparotomies (2.7 vs. 4.3, p = 0.003), and achieved primary fascial closure faster (2.4 days vs. 7.2 days, p = 0.004). On multivariate analysis, RDR (2.74; 95% confidence interval, 1.44–5.2) was an independent predictor for early fascial closure. CONCLUSION Adherence to RDR guidelines resulted in significantly decreased number of abdominal operations and was identified as an independent predictor for early fascial closure. Further investigation is warranted to validate these findings. LEVEL OF EVIDENCE Therapeutic study, level III.

The ABC's of Pancreatic Trauma: Airway, Breathing, and Computerized Tomography Scan?

OBJECTIVES Missed pancreatic injury carries significant morbidity. Computerized tomography (CT) imaging is useful, but may lack sensitivity to identify pancreatic injury. New-generation CT scanners should improve sensitivity, but this has not been studied. A previous study published in 2002 evaluating the sensitivity for identifying pancreatic injury with single-slice CT scanners yielded a 68% correlation between operative and CT findings. We aim to study the accuracy of modern CT for diagnosis and grading of pancreatic injury. METHODS All trauma admissions from 2008 and 2012 were retrospectively reviewed. Patients with a pancreatic injury, either on CT or intraoperatively, were included (n = 96). Sensitivity and specificity were calculated using Students t test. RESULTS 48 patients had injuries noted on CT and in the operating room. In this group, 68.8% had CT findings discordant with operative findings. Of these, 78.8% had no injury noted on CT, of which 26.9% required surgical intervention. Seven patients with injury on CT had none identified in the operating room. Based on these results, the sensitivity for CT imaging to identify an injury is 36.4% with a positive predictive value of 68.2%. CONCLUSIONS Our results indicate that despite advances in CT technology, the sensitivity and specificity for identifying pancreatic injury remains low. Although CT scans remain critical in trauma evaluation, awareness of this diagnostic gap is important. Further analysis is required to determine any impact on patient outcomes.

Non-human primate model of poly-traumatic hemorrhagic shock recapitulates early platelet dysfunction observed following severe injury in humans.

BACKGROUND Platelet dysfunction has been described as an early component of trauma-induced coagulopathy. The platelet component of trauma-induced coagulopathy remains to be fully elucidated and translatable animal models are required to facilitate mechanistic investigations. We sought to determine if the early platelet dysfunction described in trauma patients could be recapitulated in a nonhuman primate model of polytraumatic hemorrhagic shock. METHODS Twenty-four male rhesus macaques weighting 7 to 14 kg were subjected to 60 minutes (min) of severe pressure–targeted controlled hemorrhagic shock (HS) with and without other injuries. After 60 min, resuscitation with 0.9% NaCl and whole blood was initiated. Platelet counts and platelet aggregation assays were performed at baseline (BSLN), end of shock (EOS; T = 60 min), end of resuscitation (EOR; T = 180 min), and T = 360 min on overall cohort. Results are reported as mean ± standard deviation (SD) or median (interquartile range). Statistical analysis was conducted using Spearmen correlation, one-way analysis of variance, two-way repeated-measures analysis of variance, paired t-test or Wilcoxon nonparametric test, with p < 0.05 considered significant. RESULTS Platelet count in all injury cohorts decreased over time, but no animals developed thrombocytopenia. Correlations were observed between platelet aggregation and platelet count for all agonists: adenosine diphosphate, thrombin recognition–activating peptide-6, collagen, and arachidonic acid. Overall, compared to BSLN, platelet aggregation decreased for all agonist at EOS, EOR, and T = 360 min. When normalized to platelet count, platelet aggregation in response to agonist thrombin recognition–activating peptide-6 demonstrated no change from BSLN at subsequent time points. Aggregation to adenosine diphosphate was significantly less at EOR but not EOS or T = 360 min compared to BSLN. Platelet aggregation to collagen and arachidonic acid was not significantly different at EOS compared to BSLN but was significantly less at EOR and T = 360 min. CONCLUSION Nonhuman primates manifest early platelet dysfunction in response to polytraumatic hemorrhagic shock, consistent with that reported in severely injured human patients. Nonhuman primate models potentially are translationally valuable for understanding the mechanisms and pathophysiology of trauma-induced platelet dysfunction.

Ultrasound assessment of volume responsiveness in critically ill surgical patients: Two measurements are better than one.

BACKGROUND The intended physiologic response to a fluid bolus is an increase in stroke volume (SV). Several ultrasound (US) measures have been shown to be predictive. The best measure(s) in critically ill surgical patients remains unclear. METHODS This is a prospective observational study in critically ill surgical patients receiving a bolus of crystalloid, colloid or blood. A transthoracic echocardiogram was performed before (pre–transthoracic echocardiogram) and after. A positive volume response (+VR) was defined as a ≥15% increase in SV. Predictive measures were: left ventricular velocity time integral (VTI), respiratory SV variation (rSVV), passive leg raise SVV (plr SVV), positional internal jugular (IJ) vein change (0–90 degrees) and respiratory variation in the IJ sitting upright (90 degrees IJ). For each measure the area under the receiver operating curve (AUROC) was assessed and the best measure(s) determined. RESULTS Between November 2013 and November 2015, 199 patients completed the study. After the pilot analyses, plr SVV was abandoned because it could not be reliably assessed. VTI, rv 90 degrees IJ, 0 degree to 90 degrees IJ, were all significantly associated with VR (p < 0.05), rSVV and rv inferior vena cava were not. For VTI AUROC was 0.71 (95% confidence interval [CI], 0.64–0.77). For rv 90 degrees, it was 0.65 (95% CI, 0.57–0.71), and 0.61 (95% CI, 0.54–0.69) for 0 degrees to 90 degrees IJ. When VTI and rv 90 degrees were considered together, the AUROC rose to 0.76 (95% CI, 0.69–0.82) for the population as a whole and 0.78 (95% CI, 0.69–0.85) in mechanically ventilated patients. The positive predictive value for combined assessment was 80% and the negative 70%. CONCLUSION In a clinically relevant heterogeneous population, US is moderately predictive of VR. Inferior vena cava diameter change is not predictive. IJ change and VTI are the best measures, especially when used together. Future work should focus on combination metrics and the IJ. LEVEL OF EVIDENCE Diagnostic test, level II.

CAVH in the Combat Environment: A Case Report and Lessons Learned in Southern Afghanistan

Background Acute kidney injury is a common complication of both civilian and military trauma. The lack of dedicated resources restrict dialysis in the forward setting. We report a case of a combat polytrauma and renal failure, using continuous arteriovenous hemofiltration to clear uremia and remove volume, allowing for ventilator liberation and safe disposition. Materials and Methods The patient presented with traumatic lower extremity injuries and abdominal wounds and developed acute post-traumatic renal failure. Using available supplies, the patient was cannulated for continuous arteriovenous hemofiltration. Aggressive fluid and electrolyte management accomplished specific goals of ventilator liberation and clearance of uremia. Results Over 48 h, blood urea nitrogen was reduced from 101 mg/dL to 63 mg/dL. Creatinine was reduced from 8.2 mg/dL to 4.7 mg/dL. Acute respiratory distress syndrome was improved reducing P:F (PaO2:FiO2) ratio from 142 to 210. The patient was extubated and transferred safely. Conclusions The ability to perform acute dialysis can be lifesaving. Although resource constrained, we created a dialysis system in the forward environment with a filter and universally available equipment. This represents the first described use of continuous arteriovenous hemofiltration at the NATO Role 3 hospital in Afghanistan. This technique represents another potential tool for deployed trauma teams to improve care.

Graduating Surgical Residents Lack Competence in Critical Care Ultrasound

OBJECTIVE Ultrasound provides accessible imaging for bedside diagnostics and procedural guidance, but may lead to misdiagnosis in untrained users. The main objective of this study was to determine observed and self-perceived competence with critical care ultrasound in graduated general surgery residents. DESIGN The design of this study was a retrospective review. Ultrasound training program records were reviewed for number of prior ultrasound examinations performed, self-perceived competence, observed competence on faculty examinations, and intended future use of individual critical care ultrasound examinations. SETTING This study was undertaken at the R Adams Cowley Shock Trauma Center, which is a tertiary care center in Baltimore, MD. PARTICIPANTS Graduated general surgery residents were identified at the beginning of their surgical critical care fellowship at our institution, and were included if they participated in our critical care ultrasound education program. Fifteen graduated general surgery residents were included. RESULTS Prior ultrasound experience ranged from 100% for focused assessment of sonography for trauma (FAST) to 13.3% for advanced cardiac assessment. Self-perceived competence ranged from 46.7% with FAST to 0% for advanced cardiac assessment. Observed competence ranged from 20.0% for FAST examinations to 0% for basic cardiac assessment, advanced cardiac assessment, and inferior vena cava (IVC) assessment. All participants intended to use ultrasound in the future for FAST, pneumothorax detection and basic cardiac assessment, and 86.7% for IVC assessment and advanced cardiac assessment. Of participants with self-perceived competence, 28.6% had observed competence with FAST, 0% with IVC assessment, and 100% with pneumothorax detection. CONCLUSIONS Graduated general surgery residents are not competent in multiple critical care ultrasound examinations despite universally planning to use critical care ultrasound in future practice. Current exposure to ultrasound in residency may give a false sense of competency with ultrasound use. A standardized ultrasound curriculum is an urgent need for general surgery training.

Open Chest Wounds and Flail Chest

Thoracic injuries are commonly associated with penetrating and blunt abdominal trauma and are implicated in 50–70 % of trauma deaths [1]. Cardiac tamponade, tension pneumothorax, massive hemothorax, airway obstruction, flail chest, and open pneumothorax represent the six immediately life-threatening injuries attributed to chest trauma [2]. Accordingly, they must be accurately identified and dealt with urgently.

Ultrasound for Point-of-Care Imaging: Performing the Various Exams with Technical Tips

Ultrasound has uses in heavily resourced as well as remote, underdeveloped regions. It is being studied everywhere, even on the international space station [1]. A good working knowledge of ultrasound is essential when caring for trauma.