EVACUATION

Speed is not everything: Identifying patients who may benefit from helicopter transport despite faster ground transport.

Chen X, Gestring ML, Rosengart MR, Billiar TR, Peitzman AB, Sperry JL, Brown JB

J Trauma Acute Care Surg. 2018 Apr;84(4):549-557

BACKGROUND: Helicopter emergency medical services (HEMS) have demonstrated survival benefits over ground emergency medical services (GEMS) for trauma patient transport. While HEMS speed is often-cited, factors such as provider experience and level of care may also play a role. Our objective was to identify patient groups that may benefit from HEMS even when prehospital time for helicopter utilization is longer than GEMS transport.

METHODS: Adult patients transported by HEMS or GEMS from the scene of injury in the Pennsylvania State Trauma Registry were included. Propensity score matching was used to match HEMS and GEMS patients for likelihood of HEMS, keeping only pairs in which the HEMS patient had longer total prehospital time than the matched GEMS patient. Mixed-effects logistic regression evaluated the effect of transport mode on survival while controlling for demographics, admission physiology, transfusions, and procedures. Interaction testing between transport mode and existing trauma triage criteria was conducted and models stratified across significant interactions to determine which criteria identify patients with a significant survival benefit when transported by HEMS even when slower than GEMS.

RESULTS: From 153,729 eligible patients, 8,307 pairs were matched. HEMS total prehospital time was a median of 13minutes (IQR 6, 22) longer than GEMS. Patients with abnormal respiratory rate (OR 2.39; 95%CI 1.26-4.55, p=0.01), GCS≤8 (OR 1.61; 95%CI 1.16-2.22, p<0.01), and hemo/pneumothorax (OR 2.25; 95%CI 1.06-4.78, p=0.03) had a significant survival advantage when transported by HEMS even with longer prehospital time than GEMS. Conversely, there was no association between transport mode and survival in patients without these factors (p>0.05).

CONCLUSIONS: Patients with abnormal respiratory rate, GCS≤8, and hemo/pneumothorax benefit from HEMS transport even when GEMS transport was faster. This may indicate these patients benefit primarily from HEMS care, such as advanced airway and chest trauma management, rather than simply faster transport to a trauma center.

LEVEL OF EVIDENCE: III, Therapeutic.

Measuring US Army medical evacuation: Metrics for performance improvement.

Galvagno SM Jr, Mabry RL, Maddry J, Kharod CU, Walrath BD, Powell E, Shackelford S.

J Trauma Acute Care Surg. 2018 Jan;84(1):150-156

BACKGROUND: The US Army medical evacuation (MEDEVAC) community has maintained a reputation for high levels of success in transporting casualties from the point of injury to definitive care. This work served as a demonstration project to advance a model of quality assurance surveillance and medical direction for prehospital MEDEVAC providers within the Joint Trauma System.

METHODS: A retrospective interrupted time series analysis using prospectively collected data was performed as a process improvement project. Records were reviewed during two distinct periods: 2009 and 2014 to 2015. MEDEVAC records were matched to outcomes data available in the Department of Defense Trauma Registry. Abstracted deidentified data were reviewed for specific outcomes, procedures, and processes of care. Descriptive statistics were applied as appropriate.

RESULTS: A total of 1,008 patients were included in this study. Nine quality assurance metrics were assessed. These metrics were: airway management, management of hypoxemia, compliance with a blood transfusion protocol, interventions for hypotensive patients, quality of battlefield analgesia, temperature measurement and interventions, proportion of traumatic brain injury (TBI) patients with hypoxemia and/or hypotension, proportion of traumatic brain injury patients with an appropriate assessment, and proportion of missing data. Overall survival in the subset of patients with outcomes data available in the Department of Defense Trauma Registry was 97.5%.

CONCLUSION: The data analyzed for this study suggest overall high compliance with established tactical combat casualty care guidelines. In the present study, nearly 7% of patients had at least one documented oxygen saturation of less than 90%, and 13% of these patients had no documentation of any intervention for hypoxemia, indicating a need for training focus on airway management for hypoxemia. Advances in battlefield analgesia continued to evolve over the period when data for this study was collected. Given the inherent high-risk, high-acuity nature of prehospital advanced life support and emphasis on the use of nonphysician practitioners in an out-of-hospital setting, the need for ongoing medical oversight and quality improvement assessment is crucial.

LEVEL OF EVIDENCE: Care management, level IV.

Reexamination of a Battlefield Trauma Golden Hour Policy.

Howard JT, Kotwal RS, Santos-Lazada AR, Martin MJ, Stockinger ZT.

J Trauma Acute Care Surg. 2018 Jan;84(1):11-18

BACKGROUND: Most combat casualties who die, do so in the prehospital setting. Efforts directed toward alleviating prehospital combat trauma death, known as killed in action (KIA) mortality, have the greatest opportunity for eliminating preventable death.

METHODS: Four thousand five hundred forty-two military casualties injured in Afghanistan from September 11, 2001, to March 31, 2014, were included in this retrospective analysis to evaluate proposed explanations for observed KIA reduction after a mandate by Secretary of Defense Robert M. Gates that transport of injured service members occur within 60 minutes. Using inverse probability weighting to account for selection bias, data were analyzed using multivariable logistic regression and simulation analysis to estimate the effects of (1) gradual improvement, (2) damage control resuscitation, (3) harm from inadequate resources, (4) change in wound pattern, and (5) transport time on KIA mortality.

RESULTS: The effect of gradual improvement measured as a time trend was not significant (adjusted odds ratio [AOR], 0.99; 95% confidence interval [CI], 0.94-1.03; p = 0.58). For casualties with military Injury Severity Score of 25 or higher, the odds of KIA mortality were 83% lower for casualties who needed and received prehospital blood transfusion (AOR, 0.17; 95% CI, 0.06-0.51; p = 0.002); 33% lower for casualties receiving initial treatment by forward surgical teams (AOR, 0.67; 95% CI, 0.58-0.78; p < 0.001); 70%, 74%, and 87% lower for casualties with dominant injuries to head (AOR, 0.30; 95% CI, 0.23-0.38; p < 0.001), abdomen (AOR, 0.26, 95% CI, 0.19-0.36; p < 0.001) and extremities (AOR, 0.13; 95% CI, 0.09-0.17; p < 0.001); 35% lower for casualties categorized with blunt injuries (AOR, 0.65; 95% CI, 0.46-0.92; p = 0.01); and 39% lower for casualties transported within one hour (AOR, 0.61; 95% CI, 0.51-0.74; p < 0.001). Results of simulations in which transport times had not changed after the mandate indicate that KIA mortality would have been 1.4% higher than observed, equating to 135 more KIA deaths (95% CI, 105-164).

CONCLUSION: Reduction in KIA mortality is associated with early treatment capabilities, blunt mechanism, select body locations of injury, and rapid transport.

LEVEL OF EVIDENCE: Therapy, level III.