Background There is no consensus about the best way to teach fiberoptic intubation. This study assesses the effectiveness of a training program in which novice anesthetic residents routinely were taught fiberoptic tracheal intubation of anesthetized, paralyzed, apneic patients. Methods Eight inexperienced anesthetic residents learned fiberoptic and conventional tracheal intubation simultaneously during their first 4 months of training. All intubations were performed using general anesthesia and muscle paralysis. Of these intubations, 223 (23%) were fiberoptic and 743 (77%) were laryngoscopic. Subsequently, their intubation skills with the two techniques were studied in a prospective, single-blind randomized trial involving 131 elective patients. Intubation times, SpO2, ETCO2, hemodynamic changes on intubation, and complications were recorded for 71 fiberoptic and 57 laryngoscopic intubations. Results There were two failures of the rigid and one failure of the fiberoptic technique due to inability to intubate within 180 s. In cases of failure, the tracheas were intubated successfully after mask ventilation by the alterative technique. No hypoxemia or hypercarbia occurred in any patient. There were no differences in hemodynamic indexes nor incidence of sore throat or hoarseness between the two groups. Mean intubation times were 56 +/- 24 s (mean +/- SD) for fiberoptic and 34 +/- 10 s (mean +/- SD) for laryngoscopic (P < 0.001). Conclusions Novices taught fiberoptic intubation and rigid laryngoscopic intubation under similar conditions, with similar volumes of experience, learn both techniques well. The safety and effectiveness of this training regimen commend it for inclusion in any residency program.
Although it has been recognized that laryngeal pressure could prevent gastric inflation during mask ventilation, this aspect has been ignored in comparison with the greater benefit of preventing regurgitation. The current study was designed to assess the efficacy of cricoid pressure in reducing gastric inflation.
Doppler ultrasound has recently been used to assess changes in blood velocity in the uterine and umbilical arteries. Alterations in the ratio of systolic to diastolic velocity (S/D ratio) are believed to reflect changes in placental vascular resistance. We have used this technique to assess potential beneficial or detrimental effects of epidural anaesthesia on blood flow to the placenta. Continuous wave Doppler ultrasound was used to measure the S/D ratio in the uterine and umbilical arteries of 12 patients undergoing epidural anaesthesia prior to elective caesarean section. Anaesthesia was achieved using lidocaine and epinephrine. The S/D ratio in both the uterine and umbilical arteries remained unaltered either by the fluid preload or by the epidural anaesthesia. It is concluded that epidural anaesthesia using this technique has neither a beneficial nor detrimental effect on uterine or umbilical blood velocity in the uncomplicated pregnancy.
