For the Barbiturate therapy , High-dose barbiturates appear to be useful adjuncts in the control of intracranial hypertension refractory to other methods of therapy.
Barbiturates decrease ICP by decreasing cerebral blood volume through drug-induced cerebral vascular vasoconstriction and an associated decrease in cerebral blood flow.
This therapy in used either as a anti seizure medication or for hypnosis or sedaion or in anesthesia.
The decrease in cerebral blood flow and associated increase in the perfusion to metabolism ratio render thiopental an attractive drug for induction of anesthesia in patients with increased ICP.
An isoelectric EEG confirms the presence of maximal barbiturate induced depression of cerebra metabolic oxygen requirements by about 55%.
However, this does not improve the ultimate outcome. There is no evidence that barbiturate therapy in patients with acute severe head injury improves outcome.
Barbiturate therapy results in a fall in blood pressure in I in 4 treated patients. The hypotensive effect of Barbiturate therapy will offset any ICP lowering effect on cerebral perfusion pressure.
Preparations and dosage of barbiturate therapy
- Phenobarbitone as an antiepileptic
- Amylobarbitone (Amytal) 50 mg tablets. Hypnotic dose 50-200 mg at bedtime.
- Butobarbitone (Soneryl) 100 mg tablets. Hypnotic dose 100-200 mg at bedtime.
- Secobarbitone (Seconal) 100 mg tablets. Hypnotic dose 100 mg at bedtime.
- Thiopental sodium as an IV anesthetic.