Fluid and electrolyte balance, anaemia and blood transfusion

An understanding of the basic physiology of fluid and electrolyte balance and the impact of surgery and anaesthesia on homeostatic mechanisms is essential to safe patient management in the perioperative period. Successful fluid management also requires familiarity with both the composition and pharmacology of commonly available products for fluid replacement therapy. A greater awareness of the hazards of blood and blood components has led to significant changes in practice over the last 20 years; traditional transfusion triggers have been challenged and more restrictive strategies adopted.