**11. Organ dysfunction and its management**

Heat stroke can cause multiple organ dysfunction. We will describe the heat stroke causing multiple organ dysfunction in system-wise order.

#### **11.1 Respiratory dysfunction**

Heat stroke patients can have aspiration pneumonia, bronchospasm, noncardiogenic pulmonary edema, pneumonitis, pulmonary hemorrhage, and infection. Invasive ventilation with endotracheal intubation enables protection of the airway and management of increased metabolic demand through oxygen supplement and increased minute ventilation [9].

#### **11.2 Cardiac dysfunction**

Heat stroke can cause acute cardiac decompensation and myocardial injury, with reversible cardiac biomarkers elevation. Cardiac dysfunction and tachyarrhythmias respond well to cooling, hence anti-arrhythmics are seldom necessary, and electric cardioversion should be avoided until cooling is achieved unless necessary to treat VF (ventricular fibrillation) or PVT (pulseless ventricular tachycardia) [9].

#### **11.3 Hypotension**

Hypotension in these patients is due to volume depletion, vasodilation, and cardiac dysfunction, therapy is isotonic or crystalloid fluid resuscitation, and alphaadrenergic medication impairs cooling and should be avoided [9].

#### **11.4 CNS dysfunction**

Cerebral edema and seizure are frequent CNS complications in heat stroke patients.

A variety of cerebrovascular disorders ranging from neuropathies, Gillian-Barre Syndrome, and Parkinsonism are reported in heat stroke patients [10].

Standard anticonvulsant and anti-edema measures can be followed in these patients with continuous EEG monitoring.

#### **11.5 Rhabdomyolysis**

Rhabdomyolysis is frequent in heat stroke patients, and can be typically managed by hydration-forced diuresis and electrolyte management.

#### **11.6 Acute kidney injury**

Heat stroke patients will have AKI due to severe dehydration, or rhabdomyolysis. Serum electrolyte and renal functions should be monitored regularly and depending on AKI severity, may require renal replacement therapy.

#### **11.7 Hepatic injury**

The liver function should be monitored in patients with heat stroke, liver injury in these patients is self-limited but can progress to hepatic failure and require transplant [11].

#### **11.8 Disseminated intravascular coagulation (DIC)**

DIC is more frequent in patients with heat stroke during the initial 72 hours. All these should be monitored with traditional coagulation parameters (PT, aPTT, INR, fibrinogen, D-Dimer) and state of art management such as ROTEM. If required, DIC can be treated with the replacement of clotting factors, fresh frozen plasma, or prothrombin complex.
