A Randomized Crossover Trial of Conventional versus Modified "Koch" Chest Compressions in a Height-Restricted Aeromedical Helicopter.

Aim: Low overhead height can negatively affect chest compression performance. An adapted compression technique has been proposed by paramedic H. Koch (pron. "Cook"). This study compares conventional to Koch technique in a height-restricted aeromedical helicopter. Methods: Eighteen clinicians were randomized to 2 minutes of conventional or Koch compressions, then crossed-over. Koch technique uses a forearm/elbow instead of overlapping hands. Compression quality was assessed with a Skill Reporting Laerdal Resusci-Anne manikin. Quality variables were: the number and rate of compressions, compression depth, release, land marking, and overall aggregate quality score. Participant feedback was collected using the Borg Scale of Perceived Exertion, and compression difficulty using a zero-to-ten scale. Furthermore, we solicited open-ended descriptive responses. Results: The average overall quality score was 63% for conventional compressions versus 79% for Koch compressions (p = 0.04). On average, the Koch compression method increased compression depth by 5 mm (95% CI 4.3 to 5.7) and the proportion of compressions at the correct depth by 17% (95% CI 7.55 to 26.45), although these were not statistically significant. Correct release and land marking showed no statistically significant difference between techniques. Koch compressions resulted in statistically significant reductions in physical exertion and difficulty (p < 0.001). Qualitative feedback described modified compressions as easier and more sustainable. Conclusions: In a height-restricted aeromedical helicopter, the average overall quality score improved using Koch compressions, although the mean rate, mean depth, correct release and land marking were found to be similar between techniques. Qualitative feedback described Koch compressions as easier and more sustainable. In settings where the compressor is affected by reduced overhead working height, Koch compressions may be an advisable alternative.

Utilization Criteria for Prehospital Ultrasound in a Canadian Critical Care Helicopter Emergency Medical Service: Determining Who Might Benefit.

Introduction Prehospital ultrasound (PHUS) assessments by physicians and non-physicians are performed on medical and trauma patients with increasing frequency. Prehospital ultrasound has been shown to be of benefit by supporting interventions. Problem Which patients may benefit from PHUS has not been clearly identified. METHODS: A multi-variable logistic regression analysis was performed on a previously created retrospective dataset of five years of physician- and non-physician-performed ultrasound scans in a Canadian critical care Helicopter Emergency Medical Service (HEMS). For separate medical and trauma patient groups, the a-priori outcome assessed was patient characteristics associated with the outcome variable of "PHUS-supported intervention." RESULTS: Both models were assessed (Likelihood Ratio, Score, and Wald) as a good fit. For medical patients, the characteristics of heart rate (HR) and shock index (SI) were found to be most significant for an intervention being supported by PHUS. An extremely low HR was found to be the most significant (OR=15.86 [95% confidence interval (CI), 1.46-171.73]; P=.02). The higher the SI, the more likely that an intervention was supported by PHUS (SI 0.9 to<1.3: OR=9.15 [95% CI, 1.36-61.69]; P=.02; and SI 1.3+: OR=8.37 [95% CI, 0.69-101.66]; P=.09). For trauma patients, the characteristics of Prehospital Index (PHI) and SI were found to be most significant for PHUS support. The greatest effect was PHI, where increasing ORs were seen with increasing PHI (PHI 14-19: OR=13.36 [95% CI, 1.92-92.81]; P=.008; and PHI 20-24: OR=53.10 [95% CI, 4.83-583.86]; P=.001). Shock index was found to be similar, though, with lower impact and significance (SI 0.9 to<1.3: OR=9.11 [95% CI, 1.31-63.32]; P=.025; and SI 1.3+: OR=35.75 [95% CI, 2.51-509.81]; P=.008). CONCLUSIONS: In a critical care HEMS, markers of higher patient acuity in both medical and trauma patients were associated with occurrences when an intervention was supported by PHUS. Prospective study with in-hospital follow-up is required to confirm these hypothesis-generating results. O'Dochartaigh D , Douma M , Alexiu C , Ryan S , MacKenzie M . Utilization criteria for prehospital ultrasound in a Canadian critical care Helicopter Emergency Medical Service: determining who might benefit. Prehosp Disaster Med. 2017;32(5):536-540.