British journal of anaesthesia
-
We studied prospectively 800 paediatric patients undergoing repair of cleft lip and palate to determine the predictors of difficult laryngoscopy. The incidence of difficult laryngoscopy (Cormack and Lehane grade III and IV) was 2.95% in patients with unilateral cleft lip, 45.76% in bilateral cleft lip and 34.61% in patients with retrognathia. Tracheal intubation was successful in 99% of patients in whom laryngoscopy was difficult. There was a significant association between age and laryngoscopic view (P < 0.01).
-
Comparative Study
Differential effects of desflurane and halothane on peripheral airway smooth muscle.
Volatile anaesthetics have been shown to have direct relaxant effects on airway smooth muscle. We have examined the effects of 0.9, 1.9, and 2.8 dog MAC of desflurane and halothane on isolated proximal and distal canine airways precontracted with acetylcholine. The proximal and distal airway smooth muscle relaxed with increasing concentration of each anaesthetic in a dose-related manner. ⋯ The distal airway smooth muscle was more sensitive to volatile anaesthetics than the proximal airway smooth muscle with either halothane or desflurane at all concentrations tested. This effect may be a result of differences in cartilage content, myosin content, epithelium-dependent effects, receptor density, myofilament sensitivity to Ca2+, sarcoplasmic reticulum Ca2+ control, or ionic fluxes in the proximal airway compared with the distal airway. The increased sensitivity of airway smooth muscle to desflurane compared with halothane is not known but may be related to possible differences in the effects of Ca2+ homeostasis.