Barbiturate intoxication. Evaluation of therapy including dialysis in a large series selectively referred because of severity

Abstract

Analysis of 173 cases of barbiturate poisoning, selectively referred because of their severity revealed the following: Intoxication with short-acting barbiturates caused deeper coma and more severe complications than pheno-barbital poisoning. The average ingestion of secobarbital was 33 tablets of 100 mg and pentobarbital 31 tablets of 100 mg, whereas the average for phenobarbital was 3. 0 g (50 tablets of 60 mg). Absent pupillary light reflexes indicated a poor prognosis. The outlook was good if the corneal reflex was present. Serum barbiturate levels helped to assess the severity of the intoxication and predict the duration of coma when certain variables were controlled, notably concomitant alcohol intake, habitual intake and analeptic therapy. The duration of coma correlated with the blood phenobarbital level using the formula y=0.15x + 3. 65 and was related to the blood level of short acting barbiturates by y=0. 035x + 1.46. Analeptic therapy disrupted the natural course of barbiturate poisoning, impaired clinical judgment, and made no sustained gain in morbidity or mortality. Maintenance of a free airway and assisted ventilation using a slow rate and room air were important supportive measures. Forced diuresis increased the excretion of phenobarbital, but was less effective in secobarbital or pentobarbital poisoning. Hemodialysis was more efficient than all modifications of peritoneal dialysis and diuresis and its benefit was additive to these procedures. Comparative clearances for the three types of therapy were 30, 4 to 8, and 3 to 4 ml/minute, respectively. Indications for dialysis are outlined. The mortality was 12. 7% in this selected series. Massive dosage, delay in instituting appropriate therapy, advanced age, and cardiopulmonary complications were often seen in those who died.