Heat Stroke and Heat Exhaustion Case 1

An alcoholic man is found by police ‘asleep’ on a park bench during a hot midsummer afternoon. He is unrousable. An ambulance transports him to the local emergency department. On arrival he is noted to have warm, dry skin.

Basic observations are:

• HR = 125 bpm
• BP = 80/50 mmHg
• RR = 24 min
• SpO₂ = 91% (room air)
• Temperature = 39.2°C (axilla)
• GCS 10 (E2, V4, M4)

The patient is unable to provide a history and he appears unkempt. Further examination reveals crepitations at the right lung base. A diagnosis of aspiration pneumonia is made and treatment with IV fluids and antibiotics is commenced. As the patient is having an arterial blood gas sample taken he has a tonic-clonic seizure.

Which of the following are appropriate differential diagnoses?

The patient continues to fit.

Which of the following represents the correct sequence of treatment?

Active cooling measures are commenced.

Which of the following would be the most effective and practical in this clinical scenario?

The patient continues to have recurrent seizures. He undergoes an RSI with thiopentone as the induction agent. He remains sedated with propofol and paralysed. An internal jugular central venous line is inserted and a chest x-ray obtained. Active cooling measures continue.

Unfortunately, his blood pressure remains low despite aggressive fluid resuscitation. Continuous temperature monitoring is carried out via a rectal thermometer. His blood gas results are as follows:

• pH = 7.1
• PaCO₂ = 5.9 kPa
• PaO₂ = 9.3 kPa
• FiO₂ = 1.0
• HCO₃^– = 16.1 mmol/L
• BE = -10.1 mmol/L
• K⁺ = 6.7 mmol/L
• Na⁺ = 142 mmol/L
• Haematocrit = 0.58
• Glucose = 4.2 mmol/L
• Lactate = 8.4 mmol/L

What is the best explanation for the patient’s hypoxia?

An ECG is obtained (see image).

Which of the following may be responsible for the ECG findings?