Intravenous anaesthesia for laser surgery of the airway in children with recurrent laryngeal papillomatosis.

Abstract

Juvenile laryngeal papillomatosis is a recurrent condition that presents a number of challenges to the anaesthetist: varying degrees of airway obstruction, the child's airway is shared and safe use of a laser is required. As well as the usual considerations of laser use, the child's larynx should move as little as possible.At present the treatment of choice is laser vapourisation of the papillomata. Several anaesthetic techniques have been described, including jet ventilation, intermittent intubation, apnoeic techniques and insufflation of volatile gases with or without spontaneous ventilation (1). Endotracheal intubation has been associated with seeding of the papillomata into the distal airway.The technique at the Birmingham Children's Hospital for the past 5 years is described; it is based upon deep intravenous anaesthesia with spontaneous ventilation, supplemented by topical lignocaine. Children with significant stridor at rest are induced with volatile/oxygen mixture, otherwise the method of induction is determined by child and anaesthetist. Once the child is deeply anaesthetised the larynx of the child is sprayed with lignocaine (4 mg·kg−1). The volatile agent is then discontinued and anaesthesia is provided by an intravenous infusion of propofol and alfentanil running at 10–20 mg·kg−1·hr−1 and 20–30 mcg·kg−1·hr−1 respectively. Oxygen enriched air is delivered into the pharynx via a nasopharyngeal airway. The oxygen saturation of the child is maintained at 95–97% in order to reduce the risk of ignition of the inspired oxygen by the laser. The larynx of the child is placed in suspension to produce an open airway. Depth of anaesthesia is determined primarily by the child's ventilatory pattern (adrenaline is used topically by the surgeon for haemostasis and interferes with the child's heart rate and blood pressure). End tidal CO2 concentration was measured intermittently for the first few cases, but was always found to be in the normal range. After completion of surgery (usually 15–90 min) the child is placed in the recovery position and allowed to recover.Over the past 5 years at our hospital 11 children have undergone 112 procedures. There have been no airway complications. Recovery is not prolonged (time to spontaneous eye opening about 10–15 min). This simple technique allows excellent surgical operating conditions with unimpeded visualisation of the barely mobile larynx. There is no pollution of the operating theatre or surgeon by volatile agents. The technique is now routinely used for all microlaryngeal surgery.