Preoperative fasting: Is it based on evidence?
The rule ‘Nil by Mouth’ from midnight is used traditionally to ensure that the stomach is empty prior to induction of anaesthesia. It is clearly stated that during induction of anaesthesia, the protective laryngeal reflex is diminished, which maximises the risk of pulmonary aspiration. Even in the early days of the anaesthetic era, most people understood that prior to surgery, no intake of solid food was to be consumed. (Ljunggvist&Soreide, 2003)
Ljungvvist&Soreide (2003) explains that surgical authorities recommended that patients have fluids containing carbohydrates, for example, beef tea, during the preoperative period. In spite of this, later studies revealed anaesthetic related aspiration. This resulted in progressively firmer rules for preoperative fasting, in which case patients were informed not to consume solids and liquids prior to sugery- ‘Nil by Mouth’ from midnight. (Ljunggvist&Soreide, 2003) Over the past two decades, authors have questioned the need for such intense fasting regimes. Following this, studies have been completed, which showed that guidelines which are less intense can be used to benefit the patient. (Ljunggvist&Soreide, 2003)Ljunggvist&soreide (2003) explain that following the studies, healthy adults who are undergoing surgery, can consume clear fluids up to two hours prior to surgery. However, this does not apply to people who have got gastrointestinal deficiencies or diabetes. This is because, gastrointestinal deficiencies affects gastric emptying time. (Ljunggvist&Soreide, 2003)
Given the amount of literature available and the author’s interest in this topic, it is the intention tolook at the length of time patients are being fasted for, and to look at evidence which supports whether these lengths of time are based on evidence or preference.The essay will discuss