Vehicle Dynamics Endured by Patients during Emergency Evacuation—Ambulance versus Helicopter

Comparison of kinetic changes during helicopter medical evacuations: civilian versus military flights

BACKGROUND

Helicopter evacuation is crucial for providing medical care to casualties. Previous civilian studies have demonstrated that air transport can enhance survival rates compared with ground transport. However, there has been limited research on specific accelerations during helicopter flights, particularly in military flights. This study aims to analyse and compare the accelerations endured during civilian and military helicopter evacuations.

METHODS

Accelerations were recorded during evacuation flights from the site of injury to the first medical responders in civilian helicopter EC135 T1, and military Puma SA.330 and Caiman NH90 TTH helicopters. The research investigated global acceleration and compared acceleration distributions along the vertical, lateral and longitudinal axes. A specific comparative study of the take-off phases was also performed.

RESULTS

The analysis showed that vertical loads caused the most extreme accelerations for all types of helicopter but these extreme accelerations were rare and lasted for less than 1 s. Military flights show similar acceleration intensities to civilian flights, but accelerations are higher during short periods of the take-off phase.

CONCLUSIONS

The findings suggest that helicopter evacuations during military operations are as safe as civilian evacuations and highlight the importance of patient positioning in the aircraft. However, further research should investigate the haemodynamic response to accelerations experienced during actual evacuation flights.

Multiple Non-Covalent Cross-Linked Multifunctional Strong Hemostatic Agent for Dynamic Exposure Hemostasis

Trauma requires immediate hemostasis during primary care, as well as durable hemostasis that can withstand dynamic wound exposure. Although current hemostatic materials can treat bleeding sites in emergency situations, their mechanical strength and storage conditions limit their practical application. The simultaneous combination of good mechanical properties, storage stability, biocompatibility, and rapid hemostasis of hemostatic materials remains a challenge. In this paper, a novel hemostatic material based on multiple non-covalent bond crosslinking, which has excellent mechanical properties, good biocompatibility, storage stability, and rapid hemostasis ability, is reported. Under the drive of multiple non-covalent bonds, the flowability of hydrogel micro-modules (HM) decreases rapidly within 20 s after exposure to physiological saline. The HM form a gel barrier with a tensile strength of 62.10 kPa and an elongation at break of 1976% under multiple non-covalent bonding. Furthermore, the mechanical properties do not change significantly after 30 days of storage. Cell viability is maintained at over 80% after 3 days of incubation with the cells, and the hemolysis test shows a very low hemolysis rate (2.08%). The hemostatic gel formed by HM effectively prevents secondary bleeding in dynamic hemostasis experiments simulating transportation. This work provides a hemostatic material with comprehensive properties for practical applications.