Anaesthesia
-
A new laryngoscope has been designed, incorporating an adjustable mirror and a levered tip similar to the McCoy blade, in an attempt to bridge the gulf between simple direct laryngoscopy and fiberoptic laryngoscopy. Manual in-line neck stabilisation was used to simulate difficult laryngoscopy in 14 anaesthetised patients after full neuromuscular blockade. ⋯ The mirrored laryngoscope improved this view in 10 cases (71%) compared with five cases (36%) with the McCoy laryngoscope (p = 0.005); in seven cases (50%), the view improved to a grade 1 compared with no cases when the McCoy was used (p = 0.02). We conclude that the mirrored laryngoscope offers considerable advantages over the Macintosh and the McCoy laryngoscopes in simulated difficult laryngoscopy, is simple to use and requires no special training.
-
Comparative Study
A comparison of bispectral index and ARX-derived auditory evoked potential index in measuring the clinical interaction between ketamine and propofol anaesthesia.
We evaluated the effects of a bolus (0.4 mg.kg-1) and continuous infusion (1 mg.kg-1.h-1) of ketamine on Bispectral Index (BIS) and A-Line(R) ARX Index (AAI) during propofol anaesthesia. We included 15 ASA I patients scheduled for general anaesthesia. Induction was performed by infusion of propofol at 100 ml.h-1 until loss of consciousness. ⋯ After 1 min of baseline measurements, ketamine was administered. BIS values increased from the 3rd to the 8th min after the administration of ketamine. The AAI showed no significant increase or decrease, but between-patient variability increased.
-
Cricoid pressure is frequently used to protect the anaesthetised and paralysed patient from passive regurgitation. Although intragastric pressure (Pga) drives regurgitation, its relevance in the setting of protective cricoid force has been largely ignored. We sought to define the likely range of Pga encountered in the population at risk. ⋯ Pga (mmHg) in the whole group recorded at end-inspiration (Pga-In) and end-expiration (Pga-Ex) was [mean (SD)]: Pga-In 6.48 (2.60) mmHg and Pga-Ex 3.23 (2.24) mmHg. We found no correlation between Pga and body mass index (r2 = 0.018). These findings have implications for the level of cricoid force required to protect a patient during the induction of anaesthesia.