Rectal methohexital: concentration and length of the rectal catheters

In the study, the authors evaluated the concentration of rectal methohexital (1% vs 10%) and the length of the rectal catheter (3.8 vs 12.7 cm), on sleep-success rate, administration-sleep time, methohexital plasma concentrations, and recovery time in 85 healthy children scheduled for elective ophthalmic or ear, nose, or throat operations lasting approximately 1 h. At a dose of 25 mg/kg, the 1% solution of rectal methohexital was associated with a significant (P less than 0.05) higher sleep-success rate (95% vs 70%), shorter administration-sleep time (5.7 +/- 1.9 vs 7.0 +/- 2.0 min), higher methohexital plasma concentrations at 20 min (6.5 vs 4.7 ng/mL) and at 30 min (5.3 vs 3.7 ng/mL), and prolonged recovery time (53.2 +/- 31.1 vs 32.4 +/- 18.5 min). The length of the rectal catheters did not significantly affect sleep-success rate, administration-sleep time, methohexital plasma concentrations, or recovery time. The use of 25 mg/kg of 1% rectal methohexital solution to induce anesthesia in children is superior to the use of 25 mg/kg of 10% methohexital solution for induction of anesthesia in children, particularly in operations 1 h or longer in duration.