How long to search? -- a review
of evidence from Haiti's quake
28 Feb 2011
In an effort to assist New Zealand-based rescue efforts, the journal Disaster Medicine and Public Health Preparedness has published a series of open-access articles reviewing evidence from Haiti's 2010 earthquake and other recent seismic
disasters.
The featured article, 'Survival interval in earthquake entrapments' focuses on aiding decision-makers faced with the difficult task of weighing the potential survival of victims against
the risks to rescue workers and the need to divert efforts to other essential rebuilding tasks.
Their work, which catalogues evidence from medical records and media reports of late rescues, highlights several key
factors in determining the likelihood of survival, such as the crucial importance of void spaces in collapsed buildings,
which may well be located at ground level or even below.
They also urge caution in reporting of dramatic survival tales, pointing out that the veracity of several of the most
widely-publicised cases following Haiti's quake -- including a man who reportedly survived in the rubble of a
marketplace for 27 days -- has been called into question. Some victims later admitted to re-entering buildings, becoming
trapped several days after the initial quake.
An excerpt from the abstract:
Earthquakes can result in collapsed structures with the potential to entrap individuals. In some cases, people can
survive entrapment for lengthy periods. The search for and rescue of entrapped people is resource intensive and competes
with other post-disaster priorities. The decision to end search and rescue activities is often difficult and in some
cases protracted.
Medical providers participating in response may be consulted about the probability of continued survival in undiscovered
trapped individuals. Historically, many espouse a rigid time frame for viability of entrapped living people (eg, 2 days,
4 days, 14 days). The available medical and engineering data and media reports demonstrate a wide variety in survival
"time to rescue," arguing against the acceptance of a single time interval applicable to all incidents.
The review article's authors, Andrew Macintyre, MD, Joseph Barbera, MD and Bruno Petinaux, MD -- all of George Washington University -- state:
"Decreasing the uncertainty of whether live survivors remain under the rubble requires an integrated interdisciplinary
approach: structural engineering, technical and canine search, rescue, hazardous materials, and medical professionals
may provide relevant input. Although this multidisciplinary approach may be intuitive, it must be recognized that the
individuals making the authoritative decisions regarding transition to rescue are commonly governmental leaders in the
affected area. ...
"In the experience of the authors, the search and rescue mode is unnecessarily extended in many situations by political
leaders responding to public emotion, even with little realistic hope for additional survivors. ... It is important to
recognize that decision making by government leaders may be influenced by politics, public confidence, and the media
reporting of late "live finds." ...
"The veracity of any publicized late rescues should be rapidly investigated and if indicated, publicly corrected because
this can have adverse effects on an otherwise responsible decision to end the search phase of an emergency response."
They go on to add:
"The evolving body of published data about entrapped victims suggests a significant variability in survival across
earthquake experiences. Rather than proposing a simplified, absolute time limit for the entrapped individual's survival
interval, a more cogent decision methodology should be developed that considers the factors presented in this article.
"The potential existence of void spaces is believed to be the most influential factor to incorporate into this decision
support algorithm, followed by factors related to ventilation, available water (and to a lesser extent food), and then
other considerations. ... Current understanding strongly supports the concept that projected survival time will vary
from incident to incident and even location to location within an incident, and thus should not be based on an absolute
number."
The full article can be accessed here. Contact the Science Media Centre for media contact details.
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