On the rocks while in the air

Therapeutic hypothermia (TH) refers to the deliberate reduction of the body’s core temperature to between 32°C and 35°C for a period of 24 to 48 hours. TH has been extensively studied in various critical care conditions. To maximise its neuroprotective and edema-reducing effects, hypothermia should be initiated as soon as possible after injury. Currently, TH is primarily indicated for post cardiac arrest neuroprotection and neonatal asphyxia.

Hyperthermic conditions, such as heat stroke and traumatic brain injury (TBI), may also require whole-body cooling to maintain normothermia. TBI patients often develop hyperthermia due to posttraumatic cerebral inflammation, direct damage to the hypothalamus, or secondary infections. Regardless of the underlying cause, hyperthermia will significantly elevate metabolic demand, increase glutamate release, and amplify neutrophil activity, all of which exacerbate neuronal damage. This heightened response further compromises the injured brain, increasing vulnerability to secondary damage.

As a result, controlled and continuous normothermia (36.0°C–37.5°C) has been strongly recommended as a therapeutic strategy in the management of TBI, particularly within tier 1 and 2 of the Seattle International Severe Traumatic Brain Injury Consensus Conference ICP management protocol (Lavinio, A. Crit Care 28, 170, 2024).

The mission

Unicair was tasked with the air transport of a four-year-old patient from Germany to the US after a severe TBI, resulting from a fall from a great height. The child had undergone decompressive craniectomy, was intubated and ventilated, heavily sedated and had an external ventricular drain in place. Neuroprotective treatment with Levetiracetam, as well as antibiotic therapy with Vancomycin and Meropenem, was administered. Temperature management was achieved through continuous cooling with the Artic Sun 5000 temperature management system, a bulky piece of equipment. However, several attempts to wean the patient off the device while in hospital each resulted in a rapid increase in temperature to 39°C or higher within 1.5 hours, after which cooling was re-initiated.

The flight, which took place aboard one of our Challenger 604 aircraft with one technical stop for refuelling, lasted a total of 15 hours, including ground transport. During the flight, normothermia was maintained using a TECOtherm NEO portable cooling device. This compact, servo-controlled device is easily accommodated on medium and medium-large air ambulance aircraft (Figure 1). It effectively controls body temperature by surface cooling on a single use mattress that is connected to the unit and can be operated on servo-controlled or no-feedback, fixed mattress temperature modes. However, the device requires a 220V/100V power supply and does not operate on battery. As a contingency for potential equipment failure and to provide continuity of temperature management during ground transportation, we also carried eight cool-packs and 10kg of dry ice for re-cooling those cool-packs that are not in use with the patient.

In-flight, the patient’s intracranial pressure (ICP), vital signs, and temperature were all within the normal range for her age. The cooling mattress was maintained at 16°C throughout the transport, ensuring that her temperature remained between 36.5°C and 37.4°C.

This case demonstrates that targeted temperature control can be effectively and safely implemented during long-distance aeromedical repatriation of patients with severe TBI.