Is postoperative nausea and vomiting following tonsillectomy really a problem?

Abstract

Papers continue to appear indicating the difficulty some departments have in managing nausea and vomiting in children following tonsillectomy (Roberts & Jones. Anaesthesia 2002; 57: 619–20, Mukerjee et al.Anaesthesia 2001; 56: 1193–7). There is good evidence that with disciplined anaesthetic protocols, competent surgery and well informed patients, (and their parents) that postoperative nausea and vomiting (PONV) need not be the problem that many departments appear to experience. In 1995, the ENT department in Salisbury requested that children between the ages of 5 and 15 years be admitted for tonsillectomy to the Day Surgery Unit. It was agreed that a pilot should be undertaken to assess morbidity and appropriateness of the suggestion. The pilot study included 20 children of whom 13 (65%) were admitted following tonsillectomy with anaesthetic-related morbidity, chiefly pain and vomiting. No one anaesthetic technique was followed; anaesthetists used their own customised routine with which they were familiar for inpatient tonsillectomy. Surgical morbidity was non-existent in this group and therefore it was incumbent on the anaesthetists to resolve their problem. The surgeons were anxious to pursue day case tonsillectomy in children as an appropriate procedure. A major contributor to PONV is the presence of blood in the stomach. Williams & Bailey [1] observed that in children undergoing tonsillectomy, the reinforced laryngeal mask airway gave better protection from blood entering the airway than an uncuffed tracheal tube. As the laryngeal mask acts as an oesophageal obturator, it is as likely to prevent blood from entering the oesophagus as it is to protect the upper airway. It is suggested by Splinter et al. [2] that ondansetron is a useful agent in reducing the incidence of nausea and vomiting. Very strict guidelines were therefore drawn up for induction, maintenance of anaesthesia, analgesia and recovery. The results were dramatic and the admission rate fell from 65% to 3%[3]. In 1999, day surgery was extended to adults requiring tonsillectomy. Over 900 patients have undergone tonsillectomy as a day case procedure in the Salisbury Day Surgery Unit. In an audit of the last 538 patients, the incidence of PONV has varied between 3.3% and 8.6% on each cohort of approximately 100 patients. No patient is offered morphine postoperatively, oral analgesia (paracetamol and NSAIDs) is given within the first hour postoperatively and continued regularly every 6 h for a week. Of the 45 patients admitted (8.3%), persistent nausea and vomiting remained a problem in less than 20, less than 4% of the total. The majority of the 45 patients admitted have been adults, usually in the 16–25-year age group, who have not taken food and drink by the end of the day, that being an absolute requirement for discharge home. It is notable that in this hospital, morbidity following day case tonsillectomy is considerably lower than that following inpatient tonsillectomy. The day surgery culture focuses on reinforcing the benefits of going home, of detailed information and counselling of the patient and their parents or carers, of being meticulous over surgical and anaesthetic procedures and ensuring that oral analgesia is provided and taken regularly for 7 days postoperatively. Whilst a wide range of protocols appear to exist for the anaesthetic management of tonsillectomy, the one common factor which differs from that practised in Salisbury is the giving of morphine postoperatively. If this is not the trigger, then it clearly boils down to those factors that cannot be quantified, such as surgical expertise and an indulgently supportive environment. As I write this, a gentleman is tucking into a McDonalds double burger – he had his tonsils removed 3 h ago.