Severity Of Classic Heat Stroke Recognized

August 01, 1998

A study of patients admitted to intensive care units for heat stroke during the Chicago heat wave of July, 1995, indicates that even the extraordinary level of weather-related mortality -- more than 600 excess deaths in nine days -- radically underestimates the real consequences of that episode. In addition to the pre-hospital deaths, nearly half of the patients admitted to Chicago-area ICUs for heat stroke died within a year, 21 percent before discharge and another 28 percent after release from the hospital.

Many of the survivors suffered permanent loss of independent function; one-third had severe functional impairment at discharge and none of them had improved after one year.

The findings are reported in the August 1 issue of the Annals of Internal Medicine.

"Unlike previous descriptions of classic heat stroke, most of the patients in this study suffered from multi-system organ dysfunction, including neurologic impairment" said Maurice Ndukwu, M.D., assistant professor of medicine at the University of Chicago Medical Center and lead author of the study. "For many patients, that dysfunction persisted long after discharge."

Physicians classify heat stroke as "exertional," triggered in healthy people by intense activity in very hot and humid weather, or "classic," which usually strikes the inactive ill or elderly during prolonged heat. In this study, most patients with classic heat stroke suffered the more profound health consequences associated primarily with exertional heat stroke. They were more likely to suffer brain, kidney, and cardiovascular damage, previously considered rare in classic heat stroke.

Another troubling finding was that because of the overwhelming number of patients that inundated the city's emergency rooms, few patients received optimal treatment: immersion in cool or ice water within 30 minutes. Only one of the 58 patients in this study -- which followed every patient at 12 of the area's 24 hospitals with classic heat stroke severe enough to require ICU care -- was properly cooled within the recommended time.

"Because they presented with altered mental status, many of these patients were sent for head CT scans, delaying aggressive cooling measures," explained Ndukwu, "but the information gained from these scans did not contribute to patient management."

Unlike previous studies of classic heat stroke, Ndukwu's team found that the majority (66 percent) of patients developed kidney dysfunction and 45 percent abnormalities in blood clotting, which could contribute to subsequent liver and lung damage. They also found an unexpectedly high rate (57 percent) of pre-existing infections in patients requiring ICU care, placing these patients at additional risk.

"In this unusual episode, we saw sicker patients with more severe disease than is customary. It taught us that classic heat stroke is a deadly disorder, more complex, more often fatal and more permanently disabling than the literature on this disorder would predict. And it drove home the crucial importance of prevention and rapid diagnosis and treatment."

Additional authors of the paper include Jane Dematte, from Michael Reese Hospital; Karen O'Mara, Jennifer Buescher, Sean Forsythe, Raghavendra Adiga and Turi McNamee from the University of Chicago; and Cynthia Whitney, Centers for Disease Control and Prevention.

The research was supported by the Park Ridge Health Foundation and the University of Chicago Clinical Research Center.
-end-


University of Chicago Medical Center

Related Blood Clotting Articles from Brightsurf:

Pitt trauma experts aim to reduce deaths by providing blood-clotting agent
The study found the drug can help the most severely injured trauma patients.

Possible blood-clotting mechanism in COVID-19 found
Why so many COVID-19 patients get blood clots (thrombosis) remains uncertain.

COVID-19 causes 'hyperactivity' in blood-clotting cells
Changes in blood platelets triggered by COVID-19 could contribute to the onset of heart attacks, strokes, and other serious complications in some patients who have the disease, according to University of Utah Health scientists.

Blood clotting abnormalities reveal COVID-19 patients at risk for thrombotic events
When researchers from the University of Colorado Anschutz Medical Campus, Aurora, used a combination of two specific blood-clotting tests, they found critically ill patients infected with Coronavirus Disease 2019 (COVID-19) who were at high risk for developing renal failure, venous blood clots, and other complications associated with blood clots, such as stroke.

Blood clotting a significant cause of death in patients with COVID-19
A study led by clinician scientists at RCSI University of Medicine and Health Sciences has found that Irish patients admitted to hospital with severe COVID-19 infection are experiencing abnormal blood clotting that contributes to death in some patients.

Muscle protein abundant in the heart plays key role in blood clotting during heart attack
A prevalent heart protein known as cardiac myosin, which is released into the body when a person suffers a heart attack, can cause blood to thicken or clot--worsening damage to heart tissue, a new study shows.

Clotting problem
New research into why some people's blood doesn't clot well identified defects in the platelet-making process, where mutant cells aren't behaving properly.

Study finds trend toward benefit in using blood-clotting agent for bleeding stroke
There are few treatment options for bleeding stroke. There was a trend towards reduced growth of brain bleeds in those treated with the antifibrinolytic agent tranexamic acid within 4.5 hours of stroke onset, compared to those treated with placebo.

Study: Blood-clotting protein and blood platelets promote immune evasion, cancer progression
A new study led by researchers at The Ohio State University Comprehensive Cancer Center - Arthur G.

Laying out directions for future of reliable blood clotting molecule models
Blood clots have long been implicated in heart attacks and strokes.

Read More: Blood Clotting News and Blood Clotting Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.