Deidre L. Wyrick

Pitted Terrain on Vesta and Implications for the Presence of Volatiles

Vesta to the Core Vesta is one of the largest bodies in the main asteroid belt. Unlike most other asteroids, which are fragments of once larger bodies, Vesta is thought to have survived as a protoplanet since its formation at the beginning of the solar system (see the Perspective by Binzel, published online 20 September). Based on data obtained with the Gamma Ray and Neutron Detector aboard the Dawn spacecraft, Prettyman et al. (p. 242, published online 20 September) show that Vestas reputed volatile-poor regolith contains substantial amounts of hydrogen delivered by carbonaceous chondrite impactors. Observations of pitted terrain on Vesta obtained by Dawns Framing Camera and analyzed by Denevi et al. (p. 246, published online 20 September), provide evidence for degassing of volatiles and hence the presence of hydrated materials. Finally, paleomagnetic studies by Fu et al. (p. 238) on a meteorite originating from Vesta suggest that magnetic fields existed on the surface of the asteroid 3.7 billion years ago, supporting the past existence of a magnetic core dynamo. Analysis of data from the Dawn spacecraft implies that asteroid Vesta is rich in volatiles. We investigated the origin of unusual pitted terrain on asteroid Vesta, revealed in images from the Dawn spacecraft. Pitted terrain is characterized by irregular rimless depressions found in and around several impact craters, with a distinct morphology not observed on other airless bodies. Similar terrain is associated with numerous martian craters, where pits are thought to form through degassing of volatile-bearing material heated by the impact. Pitted terrain on Vesta may have formed in a similar manner, which indicates that portions of the surface contain a relatively large volatile component. Exogenic materials, such as water-rich carbonaceous chondrites, may be the source of volatiles, suggesting that impactor materials are preserved locally in relatively high abundance on Vesta and that impactor composition has played an important role in shaping the asteroid’s geology.

Improving gastroschisis outcomes: Does birth place matter?

PURPOSE Babies born in the hospital where they obtain definitive surgical care do not require transportation between institutions and may have shorter time to surgical intervention. Whether these differences result in meaningful improvement in outcomes has been debated. A multi-institutional retrospective study was performed comparing outcomes based on birthplace. METHODS Six institutions within the PedSRC reviewed infants born with gastroschisis from 2008 to 2013. Birthplace, perinatal, and postoperative data were collected. Based on the P-NSQIP definition, inborn was defined as birth at the pediatric hospital where repair occurred. The primary outcome was days to full enteral nutrition (FEN; 120kcal/kg/day). RESULTS 528 patients with gastroschisis were identified: 286 inborn, 242 outborn. Days to FEN, time to bowel coverage and abdominal wall closure, primary closure rate, and length of stay significantly favored inborn patients. In multivariable analysis, birthplace was not a significant predictor of time to FEN. Gestational age, presence of atresia or necrosis, primary closure rate, and time to abdominal wall closure were significant predictors. CONCLUSIONS Inborn patients had bowel coverage and definitive closure sooner with fewer days to full feeds and shorter length of stay. Birthplace appears to be important and should be considered in efforts to improve outcomes in patients with gastroschisis.

Traumatic carotid–cavernous fistula presenting as massive epistaxis

Carotid-cavernous sinus fistulae (CCF) are a rare complication with the potential for great morbidity including intracranial hemorrhage, blindness, cranial nerve palsy and stroke. Traumatic CCF are the most common type of CCF. Here we discuss a patient who sustained blunt head trauma and had substantial epistaxis, requiring massive transfusion, intraoperatively due to unrecognized CCF.

Optimal timing of appendectomy in the pediatric population

BACKGROUND No consensus has been reached on optimal timing for performing appendectomies. We compared immediate and delayed appendectomies in pediatric patients presenting with suspected acute appendicitis to determine differences in postsurgical complications and perforation rates. METHODS A retrospective cohort study was performed of all children who underwent appendectomy during a 4-y period. Cutoffs used were 6, 8, and 12 h from admission to operating room (OR). The Student t-tests and chi-square tests were performed to compare continuous and categorical variables, respectively. A logistic regression model was fitted to determine predictors of appendiceal perforation. P values <0.05 were considered significant. RESULTS Analysis included 484 patients with mean elapsed time from admission to OR of 394 min, with 262 subjects in the immediate and 222 subjects in the delayed >6 h groups. Surgical site infections (SSIs), perforations, and small bowel obstructions were similar between groups, and no statistically significant differences were found for SSIs in the nonperforated delayed versus immediate groups (P = 0.964). Time from admission to the OR did not predict perforation (P = 0.921), although white blood cell count at the time of admission was a significant predictor of perforation (odds ratio, 1.08; P < 0.001). CONCLUSIONS For suspected acute appendicitis, delaying appendectomy after admission for >6 h demonstrated no differences in SSI or perforation rates compared with immediate appendectomy. Waiting to perform an appendectomy until the following day has equal outcomes to immediate surgical procedure and may improve overall quality of patient care by limiting surgeon fatigue.

Hemodynamic variables predict outcome of emergency thoracotomy in the pediatric trauma population.

BACKGROUND Limited data exist regarding indications for resuscitative emergency thoracotomy (ETR) in the pediatric population. We attempt to define the presenting hemodynamic parameters that predict survival for pediatric patients undergoing ETR. METHODS We reviewed all pediatric patients (age <18years), entered into the National Trauma Data Bank from 2007 to 2010, who underwent ETR within one hour of ED arrival. Mechanism of injury and hemodynamics were analyzed using Chi squared and Wilcoxon tests. RESULTS 316 children (70 blunt, 240 penetrating) underwent ETR, 31% (98/316) survived to discharge. Less than 5% of patients survived when presenting SBP was ≤50mmHg or heart rate was ≤70bpm. For blunt injuries there were no survivors with a pulse ≤80bpm or SBP ≤60mmHg. When survivors were compared to nonsurvivors, blood pressure, pulse, and injury type were statistically significant when treated as independent variables and in a logistic regression model. CONCLUSIONS When ETR was performed for SBP ≤50mmHg or for heart rate ≤70bpm less than 5% of patients survived. There were no survivors of blunt trauma when SBP was ≤60mmHg or pulse was ≤80bpm. This review suggests that ETR may have limited benefit in these patients.

Persistent gastrocutaneous fistula: factors affecting the need for closure.

PURPOSE The occurrence of gastrocutaneous fistula (GCF) is a well-known complication after gastrostomy tube placement. We explore multiple factors to ascertain their impact on the rate of persistent GCF formation. METHODS We retrospectively reviewed patient records for all gastrostomies (GT) constructed at our institution from 2007 to 2011. Association of GCF with method of placement, concomitant fundoplication, neurologic findings, duration of therapy, and demographics was evaluated using logistic regression. RESULTS Nine hundred fifty patients had GTs placed, of which 148 patients had GTs removed and 47 (32%) of 148 required surgical closure secondary to persistent GCF. Laparoscopic and open procedures comprised 79 (53%) of 148 and 69 (47%) of 148, respectively. Seventeen (22%) patients in the laparoscopic group developed persistent GCF, compared to 30 (43%) in the open group (P=0.035, OR=2.52). Seventy-one patients had concomitant Nissen fundoplication. Thirty-one (44%) developed GCF, compared to 16 (21%) without a Nissen (P=0.002, OR=4.94). Patients with button in place for 303 days had persistent GCF incidence of 23%, compared to 45% at 540 days (P<0.001, OR=3.51) and 50% at 850 days (P=0.011, OR=4.51). Patients with device placed at 1.8 months of age were more likely to develop GCF compared to those with device placed at 8.9 months of age (P=0.017, OR=2.35). CONCLUSION Open operations, concurrent Nissen and younger age at placement were all statistically significant factors causing persistent GCF.

The effectiveness of a statewide trauma call center in reducing time to definitive care for severely injured patients.

BACKGROUND The state of Arkansas developed and implemented a comprehensive inclusive trauma system in July 2010. The Arkansas Trauma Communication Center (ATCC) is a central component in the system, designed to facilitate both scene transports and interfacility transfers within the state. The first 18 months of operations were examined to evaluate the relationship between ATCC use and emergency department (ED) length of stay (LOS) at sending facilities for patients who require urgent care. METHODS ATCC data were linked to the Arkansas Trauma Registry using unique identifiers. Patients younger than 15 years were excluded from the analysis. Patients older than 15 years with significant injury requiring interfacility transfer were the study population. Significant injury was defined as those with hypotension (systolic blood pressure < 90 mm Hg) or Glasgow Coma Scale (GCS) score less than 9 at the sending facility or Injury Severity Score (ISS) of 16 or greater at the definitive care facility. This cohort was stratified by the use of the ATCC, and ED LOS was determined. RESULTS The study population who met the inclusion criteria was 856; 632 (74%) of whom used the ATCC and 224 (26%) did not use the ATCC for interfacility transfers. There were no statistically significant differences noted between these two groups regarding ISS, systolic blood pressure, and GCS score. The ATCC was associated with a 21-minute reduction in the ED LOS at the sending facility when controlling for all other factors. (p = 0.005). CONCLUSION In the first 18 months following inception, the ATCC has been effective in expediting the transfer process and thus reducing the time to definitive care for severely injured patients. ATCC use has improved since inception and is now a contract deliverable for trauma hospitals based on these early results. LEVEL OF EVIDENCE Therapeutic study, level III.

Implementation of the World Health Organization checklist and debriefing improves accuracy of surgical wound class documentation

BACKGROUND Surgical wound classification (SWC) is a component of surgical site infection risk stratification. Studies have demonstrated that SWC is often incorrectly documented. This study examines the accuracy of SWC after implementation of a multifaceted plan targeted at accurate documentation. METHODS A reviewer examined operative notes of 8 pediatric operations and determined SWC for each case. This SWC was compared with nurse-documented SWC. Percent agreement pre- and postintervention was compared. Analysis was performed using chi-square and a P value less than .05 was significant. RESULTS Preintervention concordance was 58% (112/191) and postintervention was 83% (163/199, P = .001). Appendectomy accuracy was 28% and increased to 80% (P = .0005). Fundoplication accuracy increased from 44% to 84% (P = .016) and gastrostomy tube from 56% to 100% (P = .0002). The most accurate operation preintervention was pyloromyotomy and postintervention was gastrostomy tube and inguinal hernia. The least accurate pre- and postintervention was cholecystectomy. CONCLUSION Implementation of a multifaceted approach improved accuracy of documented SWC.

A multicenter, pediatric quality improvement initiative improves surgical wound class assignment, but is it enough? ☆ ☆☆ ★

BACKGROUND/PURPOSE Surgical wound classification (SWC) is widely utilized for surgical site infection (SSI) risk stratification and hospital comparisons. We previously demonstrated that nearly half of common pediatric operations are incorrectly classified in eleven hospitals. We aimed to improve multicenter, intraoperative SWC assignment through targeted quality improvement (QI) interventions. METHODS A before-and-after study from 2011-2014 at eleven childrens hospitals was conducted. The SWC recorded in the hospitals intraoperative record (hospital-based SWC) was compared to the SWC assigned by a surgeon reviewer utilizing a standardized algorithm. Study centers independently performed QI interventions. Agreement between the hospital-based and surgeon SWC was analyzed with Cohens weighted kappa and chi square. RESULTS Surgeons reviewed 2034 cases from 2011 (Period 1) and 1998 cases from 2013 (Period 2). Overall SWC agreement improved from 56% to 76% (p<0.01) and weighted kappa from 0.45 (95% CI 0.42-0.48) to 0.73 (95% CI 0.70-0.75). Median (range) improvement per institution was 23% (7-35%). A dose-response-like pattern was found between the number of interventions implemented and the amount of improvement in SWC agreement at each institution. CONCLUSIONS Intraoperative SWC assignment significantly improved after resource-intensive, multifaceted interventions. However, inaccurate wound classification still commonly occurred. SWC used in SSI risk-stratification models for hospital comparisons should be carefully evaluated.

Surgeon as Educator: Bedside Ultrasound in Hypertrophic Pyloric Stenosis

OBJECTIVE Our institution has demonstrated the diagnostic accuracy of surgeon-performed ultrasound (US) in the diagnosis of hypertrophic pyloric stenosis (HPS). Moreover, we have also shown this modality to be accurate and reproducible through surgeon-to-surgeon instruction. The purpose of this study was to determine whether a surgical resident with experience in diagnosing HPS can teach pediatric emergency medicine (PEM) fellows, with little experience in sonography, to accurately measure the pyloric channel with bedside US. METHODS A surgical resident with experience in diagnosing HPS with US-proctored 4 emergency medicine fellows for 5 bedside US examinations each. A PEM fellow, who was blinded to the results from the radiology department US, then performed bedside US and measured the pyloric channel in patients presenting to the emergency department with HPS. Results between the radiology department and the fellows were compared using the Student t test. RESULTS In total, 18 USs were performed on 17 patients. There were no false-negative or false-positive results. There was no statistical difference between the radiology department and fellow measurement when evaluating muscle width (p = 0.21, mean deviation = 0.2 mm) or channel length (p = 0.47, mean deviation = 0.6 mm). CONCLUSION Bedside-performed US technique for measuring the pylorus length and width in patients with HPS is reproducible and accurate when taught to PEM providers. The learning curve for this technique is short.