Table 1

Systemic physiology, metabolic, as well as central changes, and derangements during prolonged seizures^2–5

	< 30 mins (phase I)	⩾ 30 mins (phase II)	Hours (refractory)
Systemic physiology
Blood pressure	Increase	Decrease	Hypotension
Arterial oxygen	Decrease	Decrease	Hypoxaemia
Arterial carbon dioxide	Increase	Variable	Hypercapnia
Lung fluid	Increase	Increase	Pulmonary oedema
Autonomic activity	Increase	Increase	Arrhythmias
Temperature	Increase by 1°C	Increase by 2°C	Fever, hyperpyrexia

Metabolic (serum)
pH	Decrease	Variable	Acidosis
Lactate	Increase	Increase	Lactic acidosis
Glucose	Increase	Normal or raised	Hypoglycaemia
Potassium	Increase or normal	Increase	Hyperkalaemia
Creatine phosphokinase	Normal	Increase	Renal failure

Central
Cerebral blood flow	Increase 900%	Increase 200%	Cerebral oedema
Cerebral oxygen consumption	Increase 300%	Increase 300%	Cerebral ischaemia
Cerebral energy state	Compensated	Failing	Deficit, ischaemia