Need to know
For #TeamEEAST Last updated: 02 May 2024 at 01:27
Ahead of the forecasted significant rise in temperature over the weekend and into next week, please ensure you are familiar with temperature related illness, signs and symptoms, and the associated treatments.
We do not see a lot of heat related illness in the UK, so presentations are likely to be unfamiliar to us all. Ambulance specific guidance can be found in the JRCALC App under Heat Related Illness. Importantly, severe heat illness can result in significant morbidity and mortality, so it is important we are able to recognise and effectively treat it.
We are expecting to see a rise in heat related illness in the coming days, which is likely to have the biggest impact on vulnerable patient groups, especially young and older patients, for whom we should have increased vigilance.
Clinical assessment should consider any underlying heat illness, which may have contributed to the presenting complaint, or in fact may be the sole reason for the 999 call. We should also be mindful of potential cognitive bias, and therefore avoid making assumptions that collapses are because of the effect of heat. We should always consider other potential causes of such presentations, and adequately assess the patient to exclude those where possible.
The following information is taken from RCEM learning, and provides some helpful definitions and clinical features to look out for:
Heat syncope results from volume depletion and peripheral vasodilatation. It is important to exclude other causes of syncope before attributing a syncopal episode to heat exposure. Patients are removed to a cooler environment. Rehydration with oral or intravenous fluids usually produces a marked improvement. Patients with reduced vasomotor tone and fixed cardiac output are more susceptible to heat syncope.
Painful involuntary muscle contractions can occur in association with prolonged exertion. Large muscle groups are often involved. Heat cramps are usually self-limiting. Management simply involves cooling, rest, analgesia and rehydration with oral fluids or intravenous saline.
Heat exhaustion is a systemic disorder. Patients complain of headache and nausea. Vomiting is common and often associated with a generalised weakness. Patients are tachycardic and tachypnoeic and often sweating profusely. Orthostatic hypotension may be present. Body temperature is elevated but usually below 40 0C. Patients are water and salt depleted.
This is the worst form of heat related illness and represents complete thermoregulatory failure. The classic presentation involves three main findings
Clinical findings vary. Sweating has been reported in cases of heat stroke and core temperature may have fallen below 40.0 0C during transfer to hospital. The key distinguishing factor that identifies heat stroke is a systemic inflammatory response. Heat stroke is heat illness associated with a systemic inflammatory response leading to multi organ problems in which encephalopathy predominates. The presence of neurological problems and hot dry skin help distinguish heat stroke from heat exhaustion.
There are lots of ways to cool the hot patient. Spraying the patient with tepid water and using a fan is the most practical method (where feasible). Utilise the air conditioning in the vehicle where possible. Remove all clothing to allow for optimal cooling. Wet sheets can be loosely applied to cool the skin.
Simple adjuncts to cooling such as the use of cooled peripheral intravenous fluids and placing of icepacks in the groin and axillae are often used. Care must be taken with ice packs as prolonged skin contact may cause tissue damage, and to maximise efficiency, should be massaged against the skin. Ice packs should be applied by wrapping the pack in a cloth or towel to avoid direct contact with the skin.
The aim of cooling is not to achieve rapid normothermia, this can result in overshoot hypothermia. Rebound hyperthermia may occur after active cooling is stopped. It is also worth noting that tympanic temperatures may reduce quicker than core temperatures, so this should be taken into account when making decisions about continuation of cooling.
Intravenous fluid administration should be in line with JRCALC, to maintain adequate perfusion in the presence of circulatory compromise. Avoid over aggressive fluid administration, as this can be harmful by further compromising the cardiovascular system. Carefully monitor the response to intravenous fluid to help guide requirement for additional volume.
Standard parameters to supplemental oxygen delivery apply (target >94%).
Anyone suffering from heat stroke should be pre-alerted to the nearest emergency department. Treatment priorities should be effective cooling and commencement of supportive therapies, such as intravenous fluid or supplemental oxygen.
For any decision-making support, please call the clinical advice line in the first instance. For any critically unwell patient, please call the critical care desk on CH202.
Heat Related Illness – RCEMLearning
Joint Royal Colleges Ambulance Liaison Committee and Association of Ambulance Chief Executives (2019) JRCALC clinical guidelines [app]
Saturday 16th July 2022