Understanding trends and common characteristics of avalanche incidents allows rescuers to develop strategies and procedures that will help maximize survival chances in avalanches. Today, 90% of avalanche fatalities involve people who are recreating in avalanche terrain.
Causes of Death. The Primary causes of death in avalanche incidents are:
Burial Depth. Over 80% of avalanche fatalities are from full burials. The chances of survival are also decreased greatly if the victim is buried 100 cm or greater (<10% at >200 cm).
Terrain and Vegetation Factors. Terrain and vegetation factors significantly affect the potential for death from trauma and the probability of and depth of burial. Some of these factors include:
Environment Factors. Environmental factors showing to affect mortality rates in avalanche burials include:
Protect Against Trauma:
Reduce Burial Depth:
Reduce Burial Time:
Maximize Chance of Survival if Fully Buried:
Avalanche Airbag. Airbag technology is based on the principle of inverse segregation. Avalanche victims who wear and successfully deploy an airbag are more likely to remain on or near the avalanche debris surface, thus reducing burial depth significantly and allowing for rapid intervention.
AvaLung. AvaLungs allow buried victims to draw oxygen from the snowpack through a mouthpiece, and expel carbon dioxide behind them. This reduces the chance of the victim rebreathing carbon dioxide for up to 60 minutes. With normal CO2 levels, subjects are less susceptible to asphyxia and hypothermia.
Helmet. Helmets offer important trauma protection from trees, rocks, and debris.
Transceiver (457kHz), probe, and shovel. Burial time is directly linked to survival; the choice to omit any of these items will severely impact rescue response times. The following list highlights average rescue times by an individual rescuer with various combinations of equipment for the complete extrication of a subject buried 1m deep:
Communication Device. Communication devices such as cell phones, VHF radios, satellite phones, and other two-way satellite communication devices are critical for initiating a rapid and effective AvSAR response. Each of these devices have their limitations; anticipate and plan for them prior to use in an emergency.
Onsite Responders. Onsite responders may be members of the involved group, members of a nearby group that witnessed the incident, or members of a responding ski-patrol.
Onsite responders must be proficient in all aspects of companion rescue, contacting and communicating with external responders, be adequately fit, possess the appropriate mindset to function well in an emergency response, and always maintain situational awareness in an AvSAR.
External Responders. External responders are called to an incident as needed to assist with search and rescue efforts. They may include the following:
Agencies and organizations that have workers exposed to avalanche terrain or that may be called on to respond to an avalanche incident must have an AvSAR plan in place. The objective of the AvSAR plan is to provide guidelines for organizing and coordinating various resources and agencies in the event of an avalanche incident. The plan is specific to each agency and organization. All responding personnel must be informed and trained in all aspects of the plan. The plan should be practiced at least once a year.
An AvSAR plan includes:
Steps of an AvSAR Plan. Following these steps ensures that all rescue components are included, and that a safer, more efficient, and effective response is facilitated.
1. Record Incident Details. The information gathered from a call for assistance should accurately describe what occurred. This allows responding personnel to analyse the incident’s chain of events, determine appropriate actions, and assess which resources are needed immediately and which resources may be needed in the future.
The initial incident details are recorded on the Initial Avalanche Report Form, which must be readily available in the field books of all AvSAR Personnel.
In addition, a Communications Log is needed for documenting the chronology of information flow as the rescue is initiated and carried out.
2. Initiate Response/AvSAR Plan. A communication plan that contains protocols for contacting rescue personnel and additional external resources. These protocols are followed to ensure that all parts of the rescue are coordinated and run smoothly.
The person who records incident details must immediately contact the designated person, such as the Search Manager or Incident Commander, and clearly convey the reported information. This person then decides on the appropriate response level and resources needed, and addresses initial responder safety concerns. The dispatcher or personnel assigned to contacting resources and initiating the rescue plan must alert rescue personnel and resources in order of priority.
3. Determine Response Level. Not all incidents require the same level of response. The response level is determined by the Incident Magnitude and Complexity Table:
The initial response level can be adjusted as more information becomes available, and the response can be scaled back if the incident is less severe and complex than the original report suggested. A pre-plan that addresses various levels of response streamlines the response process and allows for rapid down- or up-sizing of the operation. Responders should consider activating resources early in the response, knowing they can be stood down if necessary.
Incident information is critical. An initial assessment of incident details is essential. Assessments should continue as more information becomes available. New information helps responders balance their risk against the survival chances of buried subjects, determine immediate resource needs, and the safest and most efficient transportation method to access /egress the incident site.
4. Determine Resource Requirements. An AvSAR resource is any stock of personnel, equipment, or planning materials that AvSAR command, support, and can draw upon to function effectively while responding to an avalanche incident. It is crucial that the correct number and type of resources are requested, and that AvSAR managers are notified that an incident response has been initiated. Available equipment resources and locations should be listed in the plan.
5. Contact Resources. Once resource requirements are determined and reported, the appropriate resources are contacted in a priority sequence using a pre-determined call list within the AvSAR plan. An annual check by rescue agencies of resource contact information ensures that names, titles, numbers, and capabilities are current and accurate. The CAA compiles a rescue resource directory containing contact information and details for all AvSAR response groups in Canada. This document is updated annual and available to all CAA member.
6. Track and Account for Resources and Subjects. An AvSAR plan has an accountability system built into it. It is critical to track and account for all resources and subjects in order to achieve maximum safety, efficiency, and effectiveness in an AvSAR response. The accountability system must be implemented at the onset of the incident response, and continue to the end of the demobilization plan. These steps ensure that the location and status of resources are accounted for at all times throughout the operation.
Agencies should utilize appropriate means of tracking resources, personnel, and subjects. A formal check-in and check-out process is also recommended.
7. Continually Re-assess. Continuous hazard assessments and effective risk control are essential to maximize the safety of responding personnel. Resource needs and response levels should also be regularly reassessed and adjusted as needed.
8. Demobilize. Demobilization occurs when the operational response is completed, or near completion. It follows an organized, well-communicated, and planned process of releasing resources from the ICS structure.
9. Return to a State of Readiness. All equipment must be returned to a state of readiness when a rescue operation is complete. Equipment must be re-stocked and completely dry. Rescue caches should be re-stocked and any used documentation forms are to be replaced with blank copies. Ideally, the responders will have time to rest physically, mentally, and emotionally. Then, the operation as a whole is reset and ready to respond again.
10. Debrief. It remains critical to discuss and document how the operation unfolded as soon as possible, and determine if any issues need to be resolved prior to the next AvSAR incident.