A cadaver study comparing three fibreoptic-assisted techniques for converting a supraglottic airway to a cuffed tracheal tube.

After rescuing an airway with a supraglottic airway device, a method to convert it to a cuffed tracheal tube is often needed. The best method to do this has never been directly studied. We compared three techniques for conversion of a standard LMA® Unique airway to a cuffed endotracheal tube using a fibrescope. The primary endpoint was time to intubation, with secondary endpoints of success rate, perceived difficulty and preferred technique. We also investigated the relationship between level of training and prior training and experience with the techniques on the primary outcome. The mean (95% CI) time to intubation using a direct tracheal tube technique of 37 (31-42) s was significantly shorter than either the Aintree intubation catheter technique at 70 (60-80) s, or a guidewire technique at 126 (110-141) s (p < 0.001). Most (13/24) participants rated the tracheal tube as their preferred technique, while 11/24 preferred the Aintree technique. In terms of perceived difficulty, 23/24, 21/24 and 9/24 participants rated the tracheal tube technique, Aintree technique and guidewire technique, respectively, as either very easy or easy. There was no relationship between prior training, prior experience or level of training on time to completion of any of the techniques. We conclude the tracheal tube and Aintree techniques both provide a rapid and easy method for conversion of a supraglottic airway device to a cuffed tracheal tube. The guidewire technique cannot be recommended.

A multiple-dose study of mexiletine (Kö 1173).

In preparation for a prospective controlled study of mexiletine in the treatment of epilepsy, a preliminary study of serum concentrations after multiple doses was performed with 8 institutionalized Caucasian adult males with uncontrolled seizures and similar weight, medical regimen, and seizure classification. Two patients each received daily dosages of 200, 400, 600 or 800 mg mexiletine administered in capsules four times a day for 7 days, in addition to their usual medication. Serum concentrations of mexiletine were determined by the Kupferberg-Yonekawa method. After the first day, serum concentrations of mexiletine were significantly higher for the 600 and 800-mg dosages than for the 200- and 400-mg dosages. The differences in serum concentration between the 200- and 400-mg dosages and between the 600- and 800-mg dosages were not significant. Serum concentrations for the 200-mg and 400-mg dosages were generally below 400 ng/ml, whereas at dosages of 600- and 800-mg, serum concentrations ranged from 400 to over 1,100 ng/ml, after the first day. Optimal dosage for this population appeared to be at least 800 mg/day. Half-life ranged from 3.5 to 7.8 hr.

The efficacy of carbamazepine combinations in epilepsy.

The efficacy and bioavailability, and tolerance to carbamazepinee when administered with phenobarbital or phenytoin or with both drugs were evaluated in a prospective, double-blind study of patients whose seizures were not completely controlled by currently available antiepileptic drugs in usually therapeutic dosages as determined by serum levels. During each of four 21-day treatment periods, one fourth of the patients received daily doses of: (1) carbamazepine (1,200 mg) and phenytoin (300 mg); (2) carbamazepine (1,200 mg) and phenobarbital (300 mg); (3) phenytoin (300 mg) and phenobarbital (300 mg); or (4) carbamazepine (1,200 mg), with phenytoin (300 mg) and phenobarbital (300 mg). The treatment periods were separated by 2 wk of each patient's usual prestudy medication. Treatment with all three drugs was the most efficacious for seizure control. Serum carbamazepine concentration was significantly decreased when the drug was administered with either phenytoin or phenobarbital or both.