1 SURG PERIOPERATIVE CARE
Fluid balance and Requirements
• 20 – 30ml/kg/day water, 1mmol/kg/day Na, 1mmol/kg/day K, 50-100g/day Glucose.
• At Risk patients – Acute presentation of diarrhoea and vomiting, reduced fluid intake, Elderly patients and patients with reduced renal reserve, Drugs that impair renal responses to fluid changes (e.g. Diuretics), Patients with low body weight/Children (↓Overall total body fluid)
• Isotonic saline (0.9%) prevents rapid cellular shifts during rehydration and excess sodium excreted by the kidneys; Potassium (e.g. Sando-K) added if loss expected e.g. Vomiting, Pancreatic or Small Bowel fistula
• Dextrose (4%) and Saline (0.18%) useful in energy supplementation as well as raising intracellular volume (Glucose influx into cells, glucose metabolism produces water)
• Hartmann’s Solution – Lower sodium than Isotonic, contains Potassium, Lactate and Calcium