Different parts of the world are experiencing extremes of temperature. Especially in the Middle East and Asia this time of the year, heatstroke is one of the commonest presentations in the emergency department (ED). Both developed and developing countries suffer from it.
Heatstroke can range from being mild to severe, and it can lead to multi-organ damage and eventually death, especially in cases not treated in time.
Heatstroke can present in various ways and may mimic other illnesses. In the ED, just like anything else, history is an essential part of management.
What is heatstroke and how does it occur?
The body functions well at a set temperature. When a person is present in extremes of temperature, dehydrated, or performs physical exertion in high temperatures, the thermoregulatory mechanism does not work effectively, causing overheating and body temperature to reach up to 40 degrees celsius. This change in body temperature, if not treated rapidly, causes different organs to deteriorate, as the organs function at the optimal temperature and a change from the normal causes their dysfunction.
Heatstroke is divided into two types – Classical or non-exertional heatstroke is common in children and the elderly who spend time outdoors in the heat and exertional heatstroke is seen in workers and soldiers who perform activities outdoors for long periods of time.
What are some risk factors that may increase the chances of developing a heat stroke?
Heatstroke can occur in almost anyone, but certain factors increase the risk, such as:
- People of extremes of age and those who work outdoors during the daytime (eg – construction workers).
- Dehydration and exposure to high temperature with inadequate ventilation.
- Certain medications such as antipsychotics, antidepressants, and diuretics etc.
How do the patients present to the ED?
The presentation of heatstroke may mimic many illnesses and history is one of the most important factors in making a decision. Here is the various presentations that can be related to heatstroke:
- High body temperature >40 degrees celsius
- Changes in behaviour
- Changes in perspiration – skin would be dry and warm to touch
- Symptoms of dehydration
- Nausea and vomiting
- Flushing of skin
- Tachypnea and tachycardia
How to evaluate the patient?
The evaluation starts with taking a history from the patient or someone accompanying them. History of heat exposure increases the suspicion. You should also see:
- Vitals signs and temperature monitoring, rectal if possible.
- Cardiac monitoring – the monitor will show sinus tachycardia
- Complete blood count (CBC), Reflo, Urea and Electrolytes, Liver and Kidney function, Lactate
- Creatine phosphokinase (CPK) levels
Management in the ED
- Start with ABC’s – patients may present in a coma and may require intubation
- Remove any excessive materials of clothing
- Cool the patient with a cooling blanket
- Fluid resuscitation – cold IV Fluids
- The target temperature is 38.5 degrees celsius
- Cold exposure – Several techniques can be used such as cold water splashes/spraying, placing a fan, immersion in an ice bath, or cold water packs
- Dantrolene – A drug that reduces heat production in the body, has shown no effect in improving outcomes in patients with heatstroke and hence is not indicated.
- Medications may be used for symptomatic relief. However, the gold standard management is rapid cooling using any of the above-mentioned methods.
What complications can occur if the patient is not treated rapidly?
- Electrolyte imbalance
- Multi-organ damage
- Neurological dysfunction
- ECG changes
What are some of the differential diagnoses of heatstroke?
- Drug ingestion and overdose
- Serotonin syndrome
How can we prevent heat stroke?
- Public education and occupational health initiatives to spread awareness amongst the public and workers to protect themselves, stay hydrated at all times, and set duty and break hours during peak daytime.
- Availability of rapid cooling equipment in emergency departments
References and Further Reading
- Abdulaziz Mulaik, Heat Illness – https://iem-student.org/heat-illness/
- Heat Stroke – Wikem”. Org, 2021, https://wikem.org/wiki/Heat_stroke.
- “Heatstroke – Symptoms And Causes”. Mayo Clinic, 2021, https://www.mayoclinic.org/diseases-conditions/heat-stroke/symptoms-causes/syc-20353581.
- Nickson, Chris. “Heat Stroke”. Life In The Fast Lane • LITFL, 2021, https://litfl.com/heat-stroke/.
- Morris A, Patel G. Heat Stroke. [Updated 2021 Jun 25]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK537135/
- Bouchama A, Cafege A, Devol EB, Labdi O, el-Assil K, Seraj M. Ineffectiveness of dantrolene sodium in the treatment of heatstroke. Crit Care Med. 1991 Feb;19(2):176-80.