High ambient temperature associated with increased mortality in nursing home residents
- Correspondence to Cari Levy
University of Colorado Denver and the Eastern Colorado Health Care System, 6646 E 17th Ave Denver, CO 80220, USA;
Methods, results and conclusions
This article addresses heat-related mortality among nursing home residents. It is a retrospective observational study of 95,808 nursing home residents in southwest Germany between 2001 and 2005 with an assessment of excess risk during a heat wave in 2003. Mortality increased by 26% at temperatures between 32.0–33.9 degrees Celsius and 62% at temperatures >34 degrees Celsius. During the 2003 heat wave, 400 excess deaths occurred. Persons ≥ 90 years of age and those with more significant care needs were at the greatest risk of mortality.
Critique of their conclusions
The authors conclude that high ambient temperatures are associated with an increase in mortality among the nursing home population. They add that prevention of heat-related death would seem feasible due to the availability of supervision in nursing homes. What is unclear is the cause of the observed excess mortality. Were these individuals dehydrated and if so, was renal failure the cause of death? Did adapting to high ambient temperatures increase body temperature thereby increasing heart rate and a higher death rate attributable to cardiovascular causes? While the authors emphasize the importance of preventive measures, without knowing what observable or measurable changes occurred in these individuals, prevention may not be possible. Perhaps there were signs of dehydration but making a clinical diagnosis of dehydration based on physical exam alone is very difficult in older adults and risk factors for insufficient fluid intake are not known.1 Certainly one could use urine specific gravity, bioimpedence measures and fluid/mean intake recordings to assess for dehydration but this is not a practical solution based on time and financial constraints in the nursing home setting. Given, the high prevalence of dehydration in nursing homes, the best solution may be to assume that all nursing home residents are dehydrated during periods of high ambient temperature and institute preventive measures even without a confirmed diagnosis. However, this may have the unintended consequence of increasing deaths attributable to fluid overload such as congestive heart failure.2
How does it fit in with previous work in the area, innovation?
Previous research has addressed heat-related mortality among the older people and those with significant co-morbidities but this is the largest study to address heat-related mortality among the nursing home population. One would expect that the increase in heat-related mortality observed should have been mitigated by residence in a nursing home where staff are available to provide medical oversight and monitoring. If prevention is possible, like all things in geriatrics, it would likely require a multidisciplinary effort consisting of relocating residents to cooler locations, verbal prompts to drink fluids, provision of fluids that are preferred by the resident and coordination with agencies that can supply temporary air cooling units.3
Clinical and nursing implications
This article suggests that heat-related mortality may be mitigated by nursing home staff. This article makes an important contribution to the literature by heightening our awareness that nursing home residents are at higher risk of heat-related mortality. Whether prevention should focus on hydration status, body temperature or some other factor is not known. Air conditioning remains uncommon in Middle-European countries. Given this fact and the effectiveness of air conditioning in preventing heat-related mortality, emergency preparedness in all nursing homes should address the provision of air conditioning during times of excess heat.
The main question left unanswered is what was the cause of death? Was it dehydration, elevated body temperature, added strain from attempting to adapt to higher temperatures or something else? Could clinicians have detected an increased pulse, respiratory rate, decreased urine output or other warning signs prior to death? I suspect many of the decedents experienced delirium in the days before death as this is often the only sign of clinical decline in the older people. This study is a call to action for research on early identification and treatment of nursing home residents at risk for heat-related death.