Propofol is superior to thiopental for intubation without muscle relaxants

PURPOSE: To compare intubating conditions and cardiovascular changes following induction of anesthesia and tracheal intubation in patients receiving either lidocaine-remifentanil-propofol or lidocaine-remifentanil-thiopental prior to induction. METHODS: In a randomized, double-blind study 76 healthy adult patients were assigned to one of two groups: lidocaine 1.5 mg.kg(-1), remifentanil 2 mug.kg(-1) and propofol 2 mg.kg(-1) (Group P) or lidocaine 1.5 mg.kg(-1), remifentanil 2 mug.kg(-1) and thiopental 5 mg.kg(-1) (Group T). Ninety seconds after the administration of the hypnotic agent, laryngoscopy and tracheal intubation were attempted. Intubating conditions were assessed as excellent, good or poor on the basis of ease of ventilation, jaw relaxation, position of the vocal cords, and patient's response to intubation and slow inflation of the tracheal cuff. The mean arterial pressure (MAP) and heart rate (HR) were measured 45 sec after hypnotic agent administration, immediately after tracheal intubation, two and five minutes after intubation. RESULTS: Excellent intubating conditions were obtained in 84% of Group P patients and 50% of Group T patients (P < 0.05). The percentage decrease from baseline MAP was significantly higher in Group P than in Group T postinduction (27.4% +/- 11.6 vs 21.8% +/- 10.0) and immediately postintubation (19.0% +/- 16.7 vs 11.2% +/- 14.9). The percentage change from baseline HR was significantly higher in Group P than in Group T postinduction (13.8% +/- 9.7 vs 0.5% +/- 12.4), immediately postintubation (8.7% +/- 13.7 vs 2.1% +/- 13.1), and two minutes postintubation (7.04% +/- 14.3 vs 3.5% +/- 14.3). CONCLUSION: Lidocaine-remifentanil-propofol is superior to lidocaine-remifentanil-thiopental for tracheal intubation without muscle relaxants. However, it induces more hypotension and bradycardia.     

Local iatrogenic complications in nasopharyngeal rhinoscleroma

The possible role of surgical manipulation in inducing local spread and cicatricial complications in rhinoscleroma is illustrated by the three cases discussed in this paper. This is especially so where its occasional presentation as polypoid lesions of the lower respiratory tract may mimic other more sinister lesions and lead to unwarranted invasive procedures by the unsuspecting clinician. The infective nature of the lesions must be appreciated and confirmed microbiologically for appropriate drug treatment to be used. The benefits of minimal surgical intervention are illustrated in the third case.     

Cimetidine-dobutamine interaction?

The report describes a patient during induction of anaesthesia for coronary artery by-pass grafting, in whom the infusion of dobutamine at a rate of 5 micrograms.kg-1.min-1 resulted in unanticipated severe hypertension. The exaggerated response may be attributed to cimetidine--dobutamine interaction.     

Assay of serum cholinesterase with succinylcholine and propionylthiocholine as substrates

Serum cholinesterase (E.C. 3.1.1.8) was assayed with succinylcholine as a substrate. The reaction was coupled with choline oxidase and peroxidase in the presence of 4-aminoantipyrine and phenol to produce a red quinone dye that was measured spectrophotometrically. The method requires 25 microliter of sample in a total volume of 1.0 ml. The mean activity for 35 adults of the usual genotype was 74.4 +/- 28 U/l (range 24-125 U/l). Succinylcholine-sensitive individuals had activities below 18 U/l. The same serum samples also were assayed with propionylthiocholine as a substrate. Activities with the two substrates showed a coefficient of correlation of 0.980 (n = 68). However, the method using propionylthiocholine showed more overlap between the activities of succinylcholine-sensitive and insensitive individuals. Assay with succinylcholine thus may offer a more effective method of screening for sensitive individuals, since some escape detection by conventional genotyping with dibucaine and fluoride.