Ondansetron in Postoperative Nausea and Vomiting [antikvár]

Chairman's Introduction R.M. Jones Imperial College of Science, Technology and Medicine, London, UK Aetiology of PON V The problems associated with postoperative nausea and vomiting (PONV) have long been recognised, and their effects delay the post-surgical recovery of the patient. Despite continuing advances in anaesthetic and surgical techniques, both the incidence and severity of PONV have remained relatively unchanged. Particular patient groups, such as children and women, are more likely to suffer from PONV, and certain types of surgery are more emetogenic than others, for example, abdominal or ear, nose and throat surgery. The incidence of PONV ranges from an average of 30% to a peak of 80% in patients undergoing eye surgery. The aetiology of PONV is, therefore, multifactorial, with no one distinct stimulus being responsible. Patient, surgery and anaesthetic factors will all contribute to the incidence and severity of PONV. In medical terms, PONV can result in aspiration pneumonia, wound rupture, electrolyte imbalance and dehydration. These will all obviously affect the successful recovery of the patient after surgery. In human terms, PONV is distressing to the patient, increasing the trauma of their experience of surgery and post-surgical recovery. Since patient recovery time and discharge from hospital may be delayed by PONV, this therefore has economic implications, particularly in day case surgery. Current Therapy Anti-emetic therapy, where used, is often confined to treatment of PONV once it has occurred, as currently available agents are variable in their efficacy. These drugs are mainly dopamine and histamine antagonists and anticholinergics, which were first developed for a wide range of gastric motility, migraine and psychiatric uses. Metoclopramide, for example, was developed to relieve nausea and vomiting caused by underlying disease, and has expanded its use into PONV. Droperidol, developed primarily as a neuroleptic agent, is also used in PONV, especially in the USA. The use of these anti-emetics has also been limited by a significant incidence of unwanted side effects, particularly extrapyramidal symptoms. There is, therefore, a need for an effective and well tolerated anti-emetic in PONV. One which, where necessary, can be given prophylactically, without the risk of complicating a patient's postoperative recovery or well-being during surgery.