Evaluation of Serotonin Release Assay and Enzyme-Linked Immunosorbent Assay Optical Density Thresholds for Heparin-Induced Thrombocytopenia in Patients on Extracorporeal Membrane Oxygenation.

OBJECTIVES: Heparin-induced thrombocytopenia is a recognized concern in patients on extracorporeal life support. The purpose of this study was to evaluate the applicability of an enzyme-linked immunosorbent assay optical density threshold less than 1 to rule out heparin-induced thrombocytopenia in patients on extracorporeal membrane oxygenation. DESIGN: Retrospective, single-center study. SETTING: Patients were recruited from a prospectively maintained database of all patients on extracorporeal membrane oxygenation from 2012 to 2018 at a tertiary referral center. PATIENTS: Forty-seven patients on extracorporeal membrane oxygenation support. INTERVENTIONS: The primary objective was to evaluate the application of enzyme-linked immunosorbent assay optical density thresholds and the serotonin release assay in patients on extracorporeal membrane oxygenation. Patients were divided into two cohorts, serotonin release assay negative and serotonin release assay positive. In order to perform a sensitivity and specificity analysis of enzyme-linked immunosorbent assay optical density thresholds, heparin-induced thrombocytopenia negative was defined as an optical density less than 1.0 and heparin-induced thrombocytopenia positive as an optical density greater than or equal to 1.0. MEASUREMENTS AND MAIN RESULTS: Utilizing the prespecified optical density thresholds, a specificity and negative predictive value of 89% and 95% were achieved, respectively. CONCLUSIONS: This assessment has helped to identify optical density thresholds for patients undergoing extracorporeal membrane oxygenation. Our data suggest that an optical density threshold of 1.0 may aid clinicians in objectively ruling out heparin-induced thrombocytopenia without sending a confirmatory serotonin release assay. Increasing the optical density threshold to 1.0 resulted in a high specificity and negative predictive value.

Non-Radiographic Severity Measurement of Pectus Excavatum.

BACKGROUND: To avoid the radiation exposure of CT imaging and the expense of CT or MRI studies, we sought to develop a non-radiographic severity measurement of pectus excavatum based on 3D photogrammetric imaging. METHODS: Over 28 mo, ten consecutive patient volunteers with pectus excavatum underwent 3D stereophotogrammetric imaging. The surface width to surface depth ratio (Surface Lengths Pectus Index), the chest deformity's surface area to total chest surface area (Pectus Surface Area Ratio), and the chest deformity's volume to total chest volume (Pectus Volume Ratio) were calculated. Simple linear regression analysis compared the Surface Lengths Pectus Index, Pectus Surface Area Ratio, and Pectus Volume Ratio calculations each to the corresponding known CT pectus index. RESULTS: The correlation between CT pectus index versus Surface Lengths Pectus Index yielded an R-squared value of 0.7637 and a P value of 0.0013. A CT pectus index of 3.4 or greater (eight patients) corresponded to a Surface Lengths Pectus Index of 1.86 or greater (six patients). The CT pectus index versus Pectus Surface Area Ratio (R-squared = 0.4627, P = 0.0305) and the CT pectus index versus the Pectus Volume Ratio (R-squared = 0.3048, P = 0.0990) demonstrated less correlation. CONCLUSION: Surface Lengths Pectus Index corresponds to the CT pectus index and may be adequate to determine severity of pectus excavatum in some patients.

The impact of morbid obesity on solid organ injury in children using the ATOMAC protocol at a pediatric level I trauma center.

INTRODUCTION: Obesity is an epidemic in the pediatric population. Childhood obesity in trauma has been associated with increased incidence of long-bone fractures, longer ICU stays, and decreased closed head injuries. We investigated for differences in the likelihood of failure of non-operative management (NOM), and injury grade using a subset of a multi-institutional, prospective database of pediatric patients with solid organ injury (SOI). METHODS: We prospectively collected data on all pediatric patients (<18years) admitted for liver or splenic injury from September 2013 to January 2016. SOI was managed based upon the ATOMAC protocol. Obesity status was derived using CDC definitions; patients were categorized as non-obese (BMI <95th percentile) or obese (BMI ≥95th percentile). The ISS, injury grade, and NOM failure rate were calculated among other data points. RESULTS: Of 1012 patients enrolled, 117 were identified as having data regarding BMI. Eighty-four percent of patients were non-obese; 16% were obese. The groups did not differ by age, sex, mechanism of injury, or associated injuries. There was no significant difference in the rate of failure of non-operative management (8.2% versus 5.3%). Obesity was associated with higher likelihood of severe (grade 4 or 5) hepatic injury (36.8% versus 15.3%, P=0.048) but not a significant difference in likelihood of severe (grade 4 or 5) splenic injury (15.3% versus 10.5%, P=0.736). Obese patients had a higher mean ISS (22.5 versus 16.1, P=0.021) and mean abdominal AIS (3.5 versus 2.9, P=0.024). CONCLUSION: Obesity is a risk factor for more severe abdominal injury, specifically liver injury, but without an associated increase in failure of NOM. This may be explained by the presence of hepatic steatosis making the liver more vulnerable to injury. A protocol based upon physiologic parameters was associated with a low rate of failure regardless of the pediatric obesity status. LEVEL OF EVIDENCE: Level II prognosis.