Authors (including presenting author) :
Yuen MSY (1), Siu YCA (1)
Affiliation :
(1) Department of Accident and Emergency, Pamela Youde Nethersole Eastern Hospital, Hong Kong
Keyword 1: :
Evidenced Based Practice
Keyword 2: :
Heat related illnesses
Introduction :
Heat related illnesses comprise a spectrum of diseases ranging from heat cramps and heat oedema, heat syncope to heat exhaustion and heat stroke. With climate changes, the prevalence of heat related illnesses is increasing. Variation in practice was noted in managing adult patient with heat related illnesses in A&E, particularly at-risk group identification, perception of fever, route of temperature monitoring and cooling methods.
Objectives :
To summarize and critically appraise evidences for management of heat related illnesses from nursing perspective in A&E
Methodology :
Johns Hopkins Evidence-based Practice (EBP) Model 2022 was adopted in appraisal. Using keyword of heat related illnesses in prehospital, A&E and ICU settings, English studies from January 2015 to March 2025 in CINAHL, EMBASE, Cochrane library, Pubmed, Medline and Ovid were pooled for analysis. Recommendations were made on 1) Early recognition of risk factors; 2) Route of temperature monitoring; 3) Mediations; 4) Cooling methods; 5) Time of cooling and 6) Fluid replacement in A&E.
Result & Outcome :
There were 52 studies recruited for analysis: 7 level I, 8 Level II, 11 level II and 26 level IV and V. Recommendation for 1) Early Recognition of risk factors: there were numerous contributing factors which were related to duration and extent of heat exposure, inability to dissipate heat, decrease thirst sensation, individual susceptibility, societal and predisposing factors. For 2) Route of temperature monitoring: rectal temperature was widely considered the standard measurement because it was reliable and practical measure of core temperature and more accurate than temporal, axillary, oral or tympanic thermometry.
For 3) Medications: the role of medications to accelerate cooling and minimize organ damage was minimal. Antipyretic was ineffective in patients with heat related illnesses.
For 4) Cooling methods: multiple studies, association and organizations recommended patents suffering from Exertional heat stroke for rapid cooling with ice sheets and ice-water immersion. Another one was the use of body bag as container, with water and ice level to patient’s anterior axillary line. It was common to use several cooling methods. Conduction heat loss such as cooling blankets, vests, helmets, automated surface cooling devices, wetting sheets and clothing, ice packs to palms and soles and areas of large vessels were used. Evaporation and convection measures were therapeutically effective, such as wetting patients with cool or tepid water and using fans to blow air across the patients. For patients suffering from Non-exertional heat stroke, literature reviews had found no standardized approach to cooling. Cold-water irrigation of nasogastric or orogastric tubes or bladder irrigation was not recommended in isolation as these methods had shown only minimal changes in core body temperature with substantial time commitment on staffs.
For 5) Time of cooling: time frame for lowering core body temperature was ideally within 30 minutes. Exceeding a time of 60 minutes to reach initial target temperature was associated with adverse outcome, including increased in mortality. Literature had a range of initial target temperature between 38 and 40OC. Wilderness medicine recommended below 40OC. For 6) Fluid replacement: Studies with fluid therapy that were specific to heat related illnesses were spare. Basic tenets used in distributive shock should apply. Fluid administration should be carefully monitored and adjusted using dynamic endpoint, ultrasound was used to access volume status and responsiveness. Normal saline was preferred because of prevalence of hyponatremia and hypochloremia due to sweat loss.
Conclusion
Heat related illnesses range from heat cramp, heat exhaustion to heat stroke; early recognition of at-risk group, rapid initiation of cooling methods and interventions can optimize the outcome of patients. The above recommendations were accepted and implemented in A&E in June 2025.
