Pulmonary aspiration of gastric contents after a priming dose of vecuronium

A case is presented of a 16-year-old girl with ectodermal dysplasia for whom dental surgery under general anaesthesia was planned. Following a priming dose of vecuronium, and immediately after injection of sodium thiopentone (5 mg·kg⁻¹) pulmonary aspiration of gastric contents occurred. It is hypothesized that, because of the rapid speed of onset of neuromuscular blocking agents on the laryngeal muscles, that partial laryngeal paralysis was present at the time of induction of anaesthesia and that this was responsible in part for the episode of pulmonary aspiration.     

Assessment of the effect of head and neck position on upper airway anatomy in sedated paediatric patients using Magnetic Resonance Imaging

Upper airway patency can be compromised when children (or adults) receive sedative medication. The study examines the effect of two different positioning techniques (use of the ‘sniff position pillow’ (SPP) and shoulder elevation (SE) on maintenance of upper airway patency using MRI in 21 children sedated with intravenous pentobarbital (5–8 mg·kg^-1). Children positioned on the SPP had a significantly greater degree of atlanto-occipital extension (P < 0.05), and a significantly greater nasopharyngeal diameter (P < 0.05) than those with shoulder elevation. The degree of atlanto-occipital extension was not significantly correlated with pharyngeal diameter (R = -0.68). No clinical signs of upper airway obstruction were noted and oxygen desaturation did not occur. Both positioning techniques were consistently associated with upper airway patency under the study conditions described. In obligate nose breathers to whom sedative agents are administered, the SPP is more likely to maintain nasopharyngeal patency than shoulder elevation.     

Infant Responses to Saline Instillations and Endotracheal Suctioning

The study examined the effects of endotracheal suction with and without saline instillation on neonates with respiratory distress. In a completely counterbalanced factorial-within-subjects design, 27 intubated neonates were randomly assigned to two orders of presentation of treatment conditions. Heart rate and blood pressure were continuously recorded throughout both treatment conditions. The ratio of arterial oxygen tension to alveolar oxygen tension was used to assess oxygenation. Results indicated that clinically stable newborns tolerated instillations of 0.25-0.5 ml. The suctioning protocol used in this study minimized changes in infants' heart rates and blood pressures.     

NEOSTIGMINE AND EDROPHONIUM ANTAGONISM OF MODERATE NEUROMUSCULAR BLOCK INDUCED BY PANCURONIUM OR TUBOCURARINE

Edrophonium and neostigmine are anticholin-esterase drugs usedcommonly to antagonize competitive neuromuscular block. Althoughit has a faster onset of action than neostigmine, edrophoniumis unreliable when used to antagonize deep neuromuscular block.We have compared the antagonist characteristics of these twodrugs when used to antagonize a moderate degree of pancuronium-or tubocurarine-induced neuromuscular block. Forty ASA I orII patients undergoing surgical procedures were allocated randomlyto receive either pancuronium 70 kg^-1 or tubo-curarine 0.5 mgkg^-1, and to receive either edrophonium 0.5 mg kg^-1 or neostigmine0.05 mg kgr^-1. Antagonism was attempted when the first responseto train-of-four (TOF) stimulation recovered spontaneously to25% of the control height. Neuromuscular function was monitoredusing the evoked integrated electromyogram of the first dorsalinterosseous muscle of the hand. Adequate recovery was definedas the achievement of a TOF ratio of 0.70 or greater. Only sevenof 20 patients who received edrophonium demonstrated adequaterecovery 30 min after antagonism. Under the conditions describedin this study, edrophonium 0.5 mg kg7 was less effective asan antagonist than neostigmine 0.05 mg kg^-1. (Br. J. Anaesth.1993; 70: 160–162)