Sevoflurane is an inhaled volatile anaesthetic that is widely used in paediatric anaesthetic practice. First described in 1975 (Wallin 1975), its use commenced in Japan in 1992 and became widespread in 1995 (Holzki 1999). Sevoflurane is a non‐pungent, insoluble agent which facilitates smooth, rapid induction and emergence (Holzki 1999; Johr 2002). However, since its introduction postoperative behavioural disturbance, observed predominantly in the paediatric population (Cole 2002; Voepel‐Lewis 2003), has become an important clinical issue. Some studies suggest that sevoflurane has the highest incidence of behavioural disturbance of all current general anaesthetics while others show conflicting results (Abbotts 2006; Foesel 2001; Johr 2002; Vlajkovic 2006).

These behavioural changes have been described in the literature using a variety of descriptive terms, such as: emergence delirium, postanaesthetic excitation, postoperative delirium and emergence agitation. There is no consensus regarding a definition (Cole 2002; Vlajkovic 2006) however the condition can be described as a mental disturbance during the recovery from general anaesthesia that consists of hallucinations, delusions and confusion manifested by moaning, restlessness, involuntary physical activity and thrashing about in the bed (Sikich 2004). For the purpose of this systematic review, the term 'emergence delirium' will be used to encompass this clinical entity. Until recently there has been no reliable and validated scale to measure emergence delirium. Concern has been expressed as to the reliability of research results and the ease of comparing studies. In 2004 the Paediatric Anaesthesia Emergence Delirium scale was developed and evaluated; it is now a reliable and valid measure of emergence delirium in children (Sikich 2004).

The potential adverse effects of emergence delirium are mostly short lived (Veyckemans 2001). It would also be unusual for children with emergence delirium to be discharged from the postanaesthetic care unit (PACU) as a restless child may cause self‐injury, the dressing or surgical site may be disrupted and indwelling devices have the potential to become dislodged. To prevent such outcomes the child may require pharmacological or physical restraint. Pharmacological management has the disadvantage of exposing the child to medications such as opioids and sedatives. These drugs could themselves have adverse effects and their administration could delay discharge from PACU or hospital. The psychological and long‐term consequences of emergence delirium are largely unknown but it has been suggested that maladaptive behaviours, for example withdrawal, sleeping and eating problems, may be associated with emergence delirium (Holzki 1999; Kain 2004). Extra care is required to manage a patient with emergence delirium, which could strain already limited nursing resources. Care‐givers are at risk of injury when managing these children and may also feel dissatisfied with the quality of anaesthetic care. Parents who witness emergence delirium may become concerned regarding future anaesthetic experiences for their child (Houck 2005). The additional costs and the potential delay to discharge may also be significant.

The exact aetiology of emergence delirium remains unclear, however research to date suggests that there are numerous predisposing factors (Voepel‐Lewis 2003). Anaesthetic factors include: rapid emergence and the intrinsic characteristic of the anaesthetic. The newer volatile anaesthetic agents, such as sevoflurane, allow faster emergence which potentially results in early manifestation of acute pain and anxiety (Wells 1999). Some authors have suggested that sevoflurane exerts a stimulating or even neurotoxic effect on the central nervous system (Constant 1999; Johr 2002; Vlajkovic 2006). Patient‐related factors include: age, preoperative anxiety and the temperament of the child. The incidence of emergence delirium is highest in preschoolers, potentially because of psychological immaturity in this age group (Voepel‐Lewis 2003). Surgical‐related factors include: pain and type of surgery. Pain may increase the incidence of emergence delirium (Lynch 1998) and the behaviour of a child in pain may mimic emergence delirium. Otorhinolaryngology and ophthalmological procedures carry an increased risk of emergence delirium, however this phenomenon has been observed even after non‐painful imaging procedures (Voepel‐Lewis 2003).

Sevoflurane may be a major contributory factor in the development of emergence delirium. Therefore, an evidence‐based understanding of the risk benefit profile regarding sevoflurane compared with other general anaesthetic agents and adjuncts would facilitate its rational and optimal use.