Development and Application of Multidimensional Lipid Libraries to Investigate Lipidomic Dysregulation Related to Smoke Inhalation Injury Severity

Lipids play many biological roles including membrane formation, protection, insulation, energy storage, and cell division. These functions have brought great interest to lipidomic studies for understanding their dysregulation in toxic exposure, inflammation, and diseases. However, lipids have shown to be analytically challenging due to their highly isomeric nature and vast concentration ranges in biological matrices. Therefore, powerful multidimensional techniques such as those integrating liquid chromatography, ion mobility spectrometry, collision induced dissociation, and mass spectrometry (LC-IMS-CID-MS) have recently been implemented to separate lipid isomers as well as provide structural information and increased feature identification confidence. These multidimensional datasets are however extremely large and highly complex, resulting in challenges in data processing and annotation. Here, we have overcome these challenges by developing sample-specific multidimensional libraries using the freely available software Skyline. Specifically, the human plasma library developed for this work contains over 500 unique, experimentally validated lipids, which is combined with adapted Skyline functions for highly confident lipid annotations such as indexed retention time (iRT) for retention time prediction and IMS drift time filtering for increased sensitivity and selectivity. For broad comparison with other lipidomic studies, this human plasma database was initially used to annotate LC-IMS-CID-MS data from a NIST SRM 1950 extract, giving comparable results to previous studies. This workflow was then utilized to assess matched plasma and bronchoalveolar lavage fluid (BALF) samples from patients with varying degrees of smoke inhalation injury to identify potential lipid-based patient prognostic and diagnostic markers.

EMS Safety and Prehospital Emergency Care of Animals

Emergency Medical Services (EMS) personnel frequently encounter animals in situations ranging from injured law enforcement canines (LEK9s) to pets with smoke inhalation injury. In recent years, several US states have enacted laws that legally allow EMS personnel to provide basic emergency care to certain animals. Currently, nine states allow some type of emergency medical treatment and/or ambulance transport of animals by EMS, and five states limit liability for vehicle damage resulting from rescuing animals trapped inside. Despite this expanding body of legislation encouraging EMS to assist animals, EMS personnel are not typically trained in the safe handling or medical treatment of animals. Interaction with veterinary patients can pose serious injury and infectious disease risks to untrained EMS personnel. Furthermore, relationships with veterinarians must be built and treatment and transport protocols must be developed for EMS agencies to appropriately care for these animals. This report serves as an initial framework from the veterinary perspective for EMS consideration regarding current legislation, safety concerns, transport protocols, and common life-saving treatments in the prehospital emergency care of animals. Increased collaboration between EMS personnel and veterinary professionals provides an opportunity to develop quality training programs for EMS and to improve disaster preparedness of the whole community.

523 Retrospective Outcomes Analysis of Tracheostomy in Paediatric Burn Population

Introduction For decades, controversy has raged regarding the placement of tracheostomy in severe paediatric burns. Numerous variables including extent of smoke inhalation injury, % TBSA burned, age of the patient, and co-morbidities among others complicate reaching consensus. Furthermore, paediatric patients are particularly susceptible to complications including inadvertent loss of airway and long-term swallowing and other anatomic issues. Additionally, previous analysis of the efficacy of tracheostomy in paediatric burn patients appears to be hindered by a lack of nationwide analysis. The aim of this study was to explore the efficacy of tracheostomy in the general paediatric burn patient population. Methods De-identified patient data was obtained from the TriNetX Research Network database. Two cohorts were identified: paediatric burn patients with tracheostomy (cohort A) and paediatric burn patients without tracheostomy (cohort B). Burn patients were identified using the ICD-10 codes T20-T25 & T30-T32. Tracheostomy was identified using the ICD-10 codes 1005887, 1014613, 31600, 31601, 31603, 31604, 31610, and Z93.0. A total of 132 patients were identified in cohort A in 23 HCOs and 83,117 patients were identified in cohort B in 38 HCOs. Infection, hypovolemia, pulmonary injury, laryngeal injury, pneumonia, and death were compared between the cohorts. Results Cohort A had a mean age of 11 (SD=5) and Cohort B had a mean age of 9 (SD=5). Paediatric burn patients with tracheostomy had a higher risk for death, infection, hypovolemia, pulmonary injury, laryngeal injury, and pneumonia when compared to their non-tracheostomy counterparts. The risk ratios for these outcomes were 62.452, 4.713, 9.267, 26.483, 116.163, and 18.154, respectively. Conclusions The analysis of the longitudinal outcomes of pediatric burn patients with tracheostomy as compared to those without tracheostomy demonstrated the tracheostomy cohort suffered much worse mortality and morbidity across several metrics. The potential benefits of tracheostomy placement in pediatric burn patients should be weighed against these outcomes.

519 The Routine Addition of Maintenance IV Fluid is Not Warranted during all Pediatric Burn Resuscitation: A Retrospective Study

Introduction Pediatric burn resuscitation has improved dramatically over the years with improved survival and outcomes. Recent studies have shown the amount of fluid given (ml/kg/%TBSA) has direct correlation to the outcomes. Over resuscitation (fluid creep) results in multiple systemic and wound complications. We hypothesize the addition of maintenance IV fluid with Parkland resuscitation fluid in younger pediatric burns (< 30kg) may not be needed to achieve adequate end points of resuscitation. Methods We performed a retrospective chart analysis of our pediatric burn patients at our institution by categorizing younger patients (< 30kg) into two groups: The maintenance IV fluid (MF) group and the resuscitation fluid (RF) only group. We identified 18 patients that met the criteria with 9 patients in each group. All of the patients in both groups were under 30kg, age range 2-8yrs, and TBSA: 16–50 %. We included 3 patients under 20% TBSA that were resuscitated due to full thickness burns and smoke inhalation injury. We analyzed their hourly and 24-hour fluid administration including all oral intake and tube feeds as well as their hourly vitals, urine output, and laboratory values during the resuscitation. Results We found that the RF group received 1.311+/- 1.295 cc/kg cc less fluid compared to the MF group without any hypoglycemic events or deleterious hemodynamic effects. The patients who had good oral intake or received tube feeds during resuscitation resulted in significantly less resuscitation volume than the estimated resuscitation volume in both groups. Conclusions We conclude that resuscitation can be safely done in pediatric burn patients under 30 kg without adding routine maintenance IV fluid. Early oral and enteral feeding is very critical in all burn patients. The volume that was administered enterally should also be considered in hourly fluid titration rates to reduce the resuscitation fluids given thereby preventing fluid creep and ensuing deleterious complications.

An Analysis of Airway Interventions in the Setting of Smoke Inhalation Injury on the Battlefield

Introduction The Committee on Tactical Combat Casualty Care and Capabilities Development and Integration Directorate cite airway burn injuries as an indication for prehospital cricothyrotomy. We sought to build on previously published data by describing for the first time the incidence of prehospital airway interventions in combat casualties who received airway management in the setting of inhalational injuries.15,26 We hypothesized that (1) airway interventions in combat casualties who suffered inhalational injury would have a higher mortality rate than those without airway intervention and (2) prehospital cricothyrotomy was used with greater incidence than endotracheal intubation. Materials and Methods Using a previously described Department of Defense Trauma Registry dataset from January 2007 to August 2016, unique casualties with documented inhalational injury were identified. Results Our predefined search codes captured 28,222 (72.8% of all encounters in the registry) of those subjects. A total of 347 (1.2%) casualties had a documented inhalational injury, 27 (7.8%) of those with at least 1 prehospital airway intervention inhalational injuries (0.09% of our dataset [n = 28,222]). Within the subset of patients with an inhalation injury, 23 underwent intubation, 2 underwent cricothyrotomy, 3 had placement of an airway adjunct not otherwise specifically listed, and 1 casualty had both a cricothyrotomy and intubation documented. No casualties had a supraglottic, nasopharyngeal, or oropharyngeal airway listed. Contrary to our hypotheses, of those with an airway intervention, 74.0% survived to hospital discharge. In multivariable regression models, when adjusting for confounders, there was no difference in survival to discharge in those with an airway intervention compared to those without. Conclusions Casualties undergoing airway intervention for inhalation injuries had similar survival adjusting for injury severity, supporting its role when indicated. Without case-specific data on airway status and interventions, it is challenging to determine if the low rate of cricothyrotomy in this population was a result of rapid transport to a more advanced provider capable of performing intubation or cricothyrotomy may not be meeting the needs of the medics.