“…There is also a reduction in plasma chloride, potassium, calcium and magnesium levels and an increase in serum bicarbonate (Malone et at., 1986). If the operation is performed under regional anaesthesia, changes in mental state ranging from confusion to coma may occur (Still and Modell, 1973;Bird et a/., 1982) and if performed under general anaesthesia, recovery from the effects of anaesthesia may be delayed (Osborn et a/., 1980). These are mainly due to cerebral oedema caused by the shift of fluid from intravascular to intercellular space.…”