Sedation in Traumatic Brain Injury

Table 5

Thiopentone
Group	Barbiturate
Mechanism of Action/Pharmacodynamics	Stimulate GABA receptors; Inhibit AMPA receptors
Neuroprotective effects	Reduces CBF, CMRO2 and ICP; Reduces MAP, therefore variable effect on CPP Raises seizure threshold
Pharmacokinetics [6]	Hepatically metabolised; 0.5% renal excretion unchanged; Elimination 𝑡1/2 11.6 h; First to zero order kinetics if plasma high; Significant accumulation
Advantages	Rapid onset of action as induction agent; Favourable effects on CBF, CMRO2 and ICP; Inexpensive
Disadvantages and major side effects	Accumulation with prolonged infusion; Hypotension; Gastroparesis; Loss of thermoregulation; Immunosuppression; Hypokalaemia during infusion; Hyperkalaemia on emergence; Life threatening arrhythmias on coma emergence
Dosage	Induction of anaesthesia: 2–5 mg/kg; EEG burst suppression: 40 mg/kg followed by infusion at 4–8 mg/kg/h, titrated to EEG
Other significant facts	May precipitate if given concurrently with IV muscle relaxants [7]
Appropriate uses in TBI	Induction of anaesthesia, with caution regarding hypotension; Refractory elevated ICP; Refractory status epilepticus