Vecuronium infusion requirements in paediatric patients in intensive care units: the use of acceleromyography.

Neuromuscular blocking drugs in intensive care units (ICU) may cause complications, including prolonged neuromuscular block as a result of overdosage and post-ventilation muscle weakness. These may be increased by using inappropriately high infusion rates for infants, in whom published studies are scarce, and by failure to monitor neuromuscular block. There is little ICU experience of acceleromyography, which may permit more reliable monitoring. To determine appropriate vecuronium infusion rates, 12 neonates/infants (median age 4 (interquartile range (IQR) 2-5) months) and 18 children (median age 3.07 (2-10 yr) were studied. The vecuronium infusion rate was adjusted to maintain train-of-four (TOF) at 1 response using the TOF guard accelerometer. Recovery time was measured from cessation of infusion until spontaneous TOF ratio recovery of 0.7. Neonates and infants required 45% less vecuronium (mean infusion rate 54.7 (SEM 4.23) micrograms kg-1 h-1) than older children (98.7 (7.07) micrograms kg-1 h-1) and had faster recovery to 70% T4/T1 (45 (IQR 20-51) min vs 65 (55-103) min), with no evidence of prolonged weakness. Routine monitoring of neuromuscular block in ICU is essential; acceleromyography is convenient and reliable.

Filtration of fentanyl is not the cause of the elevation of arterial blood pressure associated with post-bypass ultrafiltration in children.

Modified ultrafiltration after cardiopulmonary bypass in children has been shown to be associated with an increase in arterial blood pressure. As part of a series of studies to investigate the possible causes of this blood pressure elevation, the hypothesis that if filtration was removing a significant amount of fentanyl, then the increase in blood pressure might be due to pain was proposed. Ten children, aged between 0.5 and 9.3 years (median 3.8 years), weighing 5.9 to 25.5 kg (median 15.7 kg), underwent corrective cardiac surgery (incorporating modified ultrafiltration). A standard anesthetic protocol was followed, with up to 78 micrograms/kg of fentanyl given prebypass for analgesia. After completion of cardiopulmonary bypass, modified ultrafiltration was commenced at 100 mL/min until a hematocrit of 35% was reached. Samples were taken of arterial blood (prefiltration, 3, 10, and 20 minutes postfiltration), the venous reservoir blood (prefiltration) and the filtrate (5 and 10 minutes into filtration). Hemodynamic data were recorded both prefiltration and postfiltration. The hemodynamic data showed the expected rise in both systemic arterial pressure and cardiac index after ultrafiltration. The plasma fentanyl concentrations did not significantly change after ultrafiltration: 1.59 to 12.39 ng/mL (median 6.27 ng/mL) prefiltration and 2.05 to 15.59 ng/mL (6.29 ng/mL) at 3 minutes, 2.22 to 12.64 ng/mL (6.87 ng/mL) at 10 minutes, and 1.83 to 11.52 ng/mL (5.85 ng/mL) at 20 minutes postfiltration.(ABSTRACT TRUNCATED AT 250 WORDS)

Tracheal intubation in a mannikin: comparison of the Belscope with the Macintosh laryngoscope.

Tracheal intubation carries a risk of accidental oesophageal intubation; this is increased with inexperienced trainees, and in patients with a difficult airway. The recent introduction of an angulated laryngoscope, the Belscope, may permit a better view of the vocal cords and increase the accuracy of orotracheal intubation. To determine how easy it is to learn to use the Belscope compared with the traditional Macintosh laryngoscope, a group of medical students attempted to intubate a mannikin which had been modified to simulate a difficult intubation. Time to intubation was fast with both laryngoscopes, although faster with the Macintosh, but the Belscope produced an unexpected greater incidence of failed intubation.

Anaesthesia for airway obstruction in laryngo-onycho-cutaneous syndrome.

A 4-year-old boy with laryngo-onycho-cutaneous syndrome underwent excision of an obstructive vocal cord lesion. There is only one previous case report of laryngeal involvement in this syndrome but the anaesthetic management has not been reported. The anaesthetic management for microlaryngobronchoscopy and laser surgery in this child with upper airway obstruction is described.

The pressor response and laryngeal mask insertion. A comparison with tracheal intubation.

The pressor response associated with laryngoscopy and tracheal intubation may be harmful to certain patients. The laryngeal mask airway avoids the need for laryngoscopy and allows positive pressure ventilation of the lungs in appropriate patients. This study compared the pressor response of tracheal intubation with that of mask insertion in two groups of 24 and 23 healthy patients respectively. All patients were anaesthetised with thiopentone, nitrous oxide, enflurane and paralysed with atracurium. We have shown a similar, but attenuated pattern of response associated with mask insertion in comparison with laryngoscopy and intubation; significant differences between the groups were evident in arterial diastolic blood pressure immediately after insertion and again 2 minutes later. Use of the laryngeal mask may therefore offer some limited advantages over tracheal intubation in the anaesthetic management of patients where the avoidance of the pressor response is of particular concern.