Managing postoperative oliguria
This common clinical scenario is often a junior doctor's responsibility. Sam Behjati and Lee Dvorkin suggest a structured approach
A common clinical scenario that junior doctors encounter is oliguria in postoperative patients. It is not unusual to find junior doctors prescribing a fluid challenge hastily, rather than first systemically assessing the patient.
Oliguria may be defined as urine output that is inadequate to maintain physiological homoeostasis. In practice this equates to a urine output of less than 0.5 ml/kg/hr for at least two consecutive hours or a daily urine output of less than 400 ml/day (about 15 ml/hr).w1w2
Oliguria is not a clinical diagnosis but a sign that indicates an underlying disorder. So, management of oliguria must not only be aimed at restoring urine output but also at identifying and treating this underlying disorder.w1w2 Whatever the underlying cause, if left untreated oliguria may lead to acute renal failure and its sequelae, including hyperkalaemia, acidosis, and fluid overload. The key to successful management of postoperative oliguria lies in having a