Why are patients with diabetes mellitus (DM) predisposed to postoperative urinary retention?

From the Guidelines

Diabetics are predisposed to postoperative urinary retention primarily due to diabetic autonomic neuropathy affecting bladder function, and management should include careful perioperative glycemic control, early removal of urinary catheters when appropriate, monitoring for retention, and prompt intervention with intermittent catheterization if needed, as supported by the most recent guidelines 1.

Causes of Postoperative Urinary Retention in Diabetics

• Diabetic autonomic neuropathy damages the nerves controlling the bladder, leading to impaired detrusor muscle contractility and reduced bladder sensation.
• Hyperglycemia can directly impair bladder contractility and increase urine production through osmotic diuresis, further complicating postoperative voiding.
• Other contributing factors include the use of anticholinergic medications, opioid analgesics, and general anesthetics during surgery, which can exacerbate existing bladder dysfunction.

Risk Factors

• Prolonged diabetes duration and poor glycemic control increase the risk of postoperative urinary retention.
• The presence of other comorbidities, such as cardiovascular disease, can also increase the risk.

Management

• Careful perioperative glycemic control is crucial to reduce the risk of postoperative urinary retention, with a target blood glucose range of 100-180 mg/dL (5.6-10.0 mmol/L) 1.
• Early removal of urinary catheters when appropriate can help reduce the risk of urinary retention and catheter-associated urinary tract infections.
• Monitoring for retention and prompt intervention with intermittent catheterization if needed can help prevent long-term bladder damage.
• Avoiding medications that worsen urinary retention and encouraging early mobilization can also help reduce this complication in diabetic surgical patients.

Recommendations

• The most recent guidelines recommend careful perioperative glycemic control and early removal of urinary catheters when appropriate to reduce the risk of postoperative urinary retention 1.
• The use of basal insulin plus premeal short- or rapid-acting insulin (basal-bolus) coverage has been associated with improved glycemic outcomes and lower rates of perioperative complications compared with reactive, correction-only short- or rapid-acting insulin coverage alone with no basal insulin dosing 1.

From the Research

Risk Factors for Postoperative Urinary Retention in Diabetics

• Diabetes mellitus is a significant independent risk factor for postoperative urinary retention, with an odds ratio of 5.9 2.
• The prevalence of postoperative urinary retention in a general surgical population is approximately 5%, and co-existing diabetes mellitus is a pre-disposing factor 2.
• Other risk factors for postoperative urinary retention include spinal anesthesia, longer surgery time, and older age 3.
• Patient demographics, such as lower BMI, longer operative duration, and lower ASA scores, may also contribute to the development of postoperative urinary retention 4.

Mechanisms Underlying Postoperative Urinary Retention in Diabetics

• Treatment-induced neuropathy of diabetes, also referred to as insulin neuritis, is a rare iatrogenic small fibre neuropathy caused by an abrupt improvement in glycaemic control in the setting of chronic hyperglycaemia 5.
• Rapid glycaemic change in patients with uncontrolled diabetes increases the risk of treatment-induced neuropathy of diabetes, which may contribute to postoperative urinary retention 5.
• Autonomic dysfunction, including parasympathetic and sympathetic adrenergic dysfunction, may also play a role in the development of postoperative urinary retention in diabetics 5.

Clinical Implications

• Identifying patients at risk of postoperative urinary retention, including those with diabetes mellitus, is crucial for timely intervention and prevention of complications [(2,6)].
• Regular bladder volume scanning and using the individual maximum bladder capacity as a volume threshold for urinary catheterization may help avoid unnecessary urinary catheterization and prevent bladder overdistention 3.
• Appropriate pain control and judicious use of perioperative medications, such as NSAIDs and glycopyrrolate, may also help minimize the risk of postoperative urinary retention 4.