Radiological aspects of injuries of avalanche victims

On-site treatment of avalanche victims: Scoping review and 2023 recommendations of the international commission for mountain emergency medicine (ICAR MedCom)

INTRODUCTION

The International Commission for Mountain Emergency Medicine (ICAR MedCom) developed updated recommendations for the management of avalanche victims.

METHODS

ICAR MedCom created Population Intervention Comparator Outcome (PICO) questions and conducted a scoping review of the literature. We evaluated and graded the evidence using the American College of Chest Physicians system.

RESULTS

We included 120 studies including original data in the qualitative synthesis. There were 45 retrospective studies (38%), 44 case reports or case series (37%), and 18 prospective studies on volunteers (15%). The main cause of death from avalanche burial was asphyxia (range of all studies 65-100%). Trauma was the second most common cause of death (5-29%). Hypothermia accounted for few deaths (0-4%).

CONCLUSIONS AND RECOMMENDATIONS

For a victim with a burial time ≤ 60 minutes without signs of life, presume asphyxia and provide rescue breaths as soon as possible, regardless of airway patency. For a victim with a burial time > 60 minutes, no signs of life but a patent airway or airway with unknown patency, presume that a primary hypothermic CA has occurred and initiate cardiopulmonary resuscitation (CPR) unless temperature can be measured to rule out hypothermic cardiac arrest. For a victim buried > 60 minutes without signs of life and with an obstructed airway, if core temperature cannot be measured, rescuers can presume asphyxia-induced CA, and should not initiate CPR. If core temperature can be measured, for a victim without signs of life, with a patent airway, and with a core temperature < 30 °C attempt resuscitation, regardless of burial duration.

Serum potassium concentration predicts brain hypoxia on CT after avalanche-induced cardiac arrest

BACKGROUND

Brain anoxia after complete avalanche burial and cardiac arrest (CA) may occur despite adequate on-site triage.

PURPOSE

To investigate clinical and biological parameters associated with brain hypoxia in a cohort of avalanche victims with whole body computed tomographic (CT) scan.

METHODS

Retrospective study of patients with CA and whole body CT scan following complete avalanche burial admitted in a level-I trauma center.

MAIN FINDINGS

Out of 19 buried patients with whole body CT scan, eight patients had refractory CA and 11 patients had pre-hospital return of spontaneous circulation. Six patients survived at hospital discharge and only two had good neurologic outcome. Twelve patients had signs of brain hypoxia on initial CT scan, defined as brain edema, loss of gray/white matter differentiation and/or hypodensity of basal ganglia. No clinical pre-hospital parameter was associated with brain anoxia. Serum potassium concentration at admission was higher in patients with brain anoxia as compared to patients with normal CT scan: 5.5 (4.1-7.2) mmol/L versus 3.3 (3.0-4.2) mmol/L, respectively (P<.01). A threshold of 4.35 mmol/L serum potassium had 100% specificity to predict brain anoxia on brain CT scan.

CONCLUSIONS

Serum potassium concentration had good predictive value for brain anoxia after complete avalanche burial. This finding further supports the use of serum potassium concentration for extracorporeal life support insertion at hospital admission in this context.

The prehospital management of avalanche victims

Avalanche accidents are frequently lethal events with an overall mortality of 23%. Mortality increases dramatically to 50% in instances of complete burial. With modern day dense networks of ambulance services and rescue helicopters, health workers often become involved during the early stages of avalanche rescue. Historically, some of the most devastating avalanche accidents have involved military personnel. Armed forces are frequently deployed to mountain regions in order to train for mountain warfare or as part of ongoing conflicts. Furthermore, military units are frequently called to assist civilian organised rescue in avalanche rescue operations. It is therefore important that clinicians associated with units operating in mountain regions have an understanding of, the medical management of avalanche victims, and of the preceding rescue phase. The ensuing review of the available literature aims to describe the pathophysiology particular to avalanche victims and to outline a structured approach to the search, rescue and prehospital medical management.

Outcome of avalanche victims with out-of-hospital cardiac arrest

STUDY BACKGROUND

Previous studies focused on the outcome of avalanche victims with out-of-hospital cardiac arrest (OHCA) after long duration of burial (>35min); the outcome of victims with short duration (≤35min) remains obscure.

AIM OF THE STUDY

To investigate outcome of avalanche victims with OHCA.

METHODS

Retrospective analysis of avalanche victims with OHCA between 2008 and 2013 in the Tyrolean Alps.

RESULTS

55 avalanche victims were identified, 32 of whom were declared dead after extrication without cardiopulmonary resuscitation (CPR), all with long duration of burial. In the remaining 23 CPR was initiated at scene; three were partially and 20 completely buried, nine of whom suffered short and 11 long duration of burial. All nine victims with short duration of burial underwent restoration of spontaneous circulation (ROSC) at scene, four of them after bystander CPR, five after advanced life support by the emergency physician. Two patients with ROSC after short duration of burial and bystander CPR survived to hospital discharge with cerebral performance category 1. None of the 11 victims with long duration of burial survived to hospital discharge, although six were transported to hospital with ongoing CPR and three were supported with extracorporeal circulation.

CONCLUSIONS

In this case series survival with favourable neurological outcome was observed in avalanche victims with short duration of burial only if bystander CPR was immediately performed and ROSC achieved. Strategies for reducing avalanche mortality should focus on prompt extrication from the snow and immediate bystander CPR by uninjured companions.

The pattern of acute injuries in patients from alpine skiing accidents has changed during 2000-2011: analysis of clinical and radiological data at a level I trauma center

OBJECTIVES

During the last decade, many educational efforts and technological improvements have been made to protect skiing athletes from injuries. Whether these efforts have changed the pattern of acute injuries from skiing casualties has not yet been shown on a medical basis, which this longitudinal study examines.

METHODS

All patients transferred to the Department of Radiology of our level I trauma center for acute emergency computed tomography (CT) after alpine skiing accidents from 2000 to 2011 were included. We hypothesized that only patients with clinical suspicion for injuries were admitted for acute CT.

RESULTS

Of all acute patients after skiing accidents, 2,252 could be included. From 2000 to 2011, all cerebral injuries and vascular arterial injuries statistically significantly decreased (p < 0.05, respectively). However, extremity fractures, facial fractures, and vertebral fractures increased (p < 0.04, respectively). The number of cerebral hemorrhages, thoracic injuries, and abdominal injuries remained unchanged (p = NS). The mean (SD) number of all initial radiological examinations per victim statistically significantly decreased from 2.3 (0.7) in 2000 to 1.5 (0.6) in 2011, whereas the admissions for acute CT have significantly increased (p < 0.02; respectively).

CONCLUSIONS

Acute radiological evaluation in skiing accidents has changed during the last decade. The decrease in overall cerebral injuries might be a function of the increasing use of skiing helmets. A protection of the extremities, trunk, spine, and face, however, needs further improvements and their radiological assessment with CT warrants attention in skiing casualties.