Preoperative anxiety sensitivity index in predicting postoperative nausea and vomiting : A prospective observational study.

Postoperative nausea and vomiting (PONV) is an unpleasant side effect for patients undergoing surgery under general anaesthesia and must be given equal importance as the treatment of postoperative pain. This symptom can affect the quality of recovery after surgery. In spite of giving the patients prophylactic antiemetic treatment before or during surgery, the incidence of PONV is still high. There are multiple established independent risk factors for PONV such as female sex, history of PONV or motion sickness, non-smoking status and age. Anaesthesia and surgery related predictors, such as use of volatile anaesthetic agents or postoperative use of opioids and the type of surgery are also established risk factors. The frequently used Apfel- Score includes four risk factors (female sex, non-smoking status, motion sickness or history of PONV and the expected postoperative administration of opioids). In addition to it, studies have suggested preoperative anxiety could also be a predictor of PONV. Although the Apfel score and other scoring systems are well established and often used to define standardised procedures for a risk based antiemetic strategy for patients with an increased risk for PONV, about 30% of patients still suffer from PONV.

The influence of psychological factors such as anxiety as a cause of PONV has not been explored sufficiently so far. Anxiety sensitivity can be described as the ‘fear of fear’ or the fear of anxiety. Anxiety sensitivity is a psychological construct which describes the tendency of a person to fear the sensations caused by anxiety (e.g. those sensations following activation of the sympathetic nervous system: tachycardia, palpitations, dyspnoea, sweating or trembling) because of a belief that these symptoms can have negative consequences. Anxiety sensitivity is believed to intensify states of fear and anxiety.

A recent study conducted on patients with increased risk of PONV i.e. female non-smokers undergoing elective surgery under general anaesthesia has shown that anxiety sensitivity can predict the risk of PONV. This study is undertaken to predict PONV by using anxiety sensitivity index.