The relevance of hyponatraemia to perioperative care of surgical patients

BackgroundHyponatraemia is the most common electrolyte disturbance in hospitalized patients. There is an increasing awareness of the impact of hyponatraemia on the perioperative management of surgical patients.MethodsWe performed a literature review. We have included relevant data from different surgical disciplines for analysis. In this review we discuss the differential diagnosis of hyponatraemia, and explain the specific relevance of hyponatraemia to pre-, peri- and post-operative care.ResultsHyponatraemia is common during the preoperative period and is associated with an increase in subsequent peri-operative complications, such as wound infection, pneumonia, higher mortality rate and higher direct and indirect costs. Furthermore, data shows poorer surgical outcomes when plasma sodium concentration drops. Careful preoperative evaluation of the hyponatraemic patient enables assessment of surgical risk and individualization of the management of hyponatraemia.ConclusionsWe outline a practical guide to the assessment of the cause of hyponatraemia, which dictates the correct management of hyponatraemia and the correct selection of perioperative fluids. Finally, for the therapeutic role of the new vasopressin antagonist drugs in the treatment of surgical hyponatraemia is discussed in two illustrative surgical clinical cases.