A urinary catheter is a flexible tube inserted into the bladder to drain urine; the most common type used in surgical settings is the Foley catheter. This indwelling device has a small, inflatable balloon at its tip that is filled with sterile water after insertion. The balloon holds the catheter securely in place within the bladder. A catheter is not routinely used in every surgical procedure, and placement is based strictly on medical necessity, balancing the benefits of continuous drainage against the risk of infection.
Criteria for Catheter Use
The decision to place a catheter revolves around anticipating the patient’s needs during and immediately following the operation. One of the most common indications is the expected duration of the procedure, with many institutions considering placement for surgeries lasting two hours or longer. This timeframe is often used because prolonged anesthesia can temporarily impair bladder sensation and function, increasing the risk of the bladder becoming overfull.
Specific types of surgery necessitate catheter use to ensure patient safety and optimize the surgical field. Procedures involving the pelvis, abdomen, or urinary tract (such as gynecological or urological operations) often require a decompressed bladder. Patients who are critically ill or undergoing procedures involving large fluid shifts require continuous monitoring of urine output. This measurement reflects kidney function and overall fluid status, which is relevant to anesthesia management.
Patients with pre-existing conditions causing urinary retention or those requiring prolonged immobilization after surgery may also need a temporary indwelling catheter.
Essential Functions During Surgery
Once the need is established, the catheter performs several functions important for the patient’s physiology and the technical demands of the operation. A primary function is bladder decompression, which keeps the bladder empty throughout the procedure. This is important during abdominal and pelvic surgeries, as a full bladder can obstruct the surgeon’s view and increase the risk of accidental injury.
Maintaining accurate tracking of fluid balance is another significant function, especially in long or complex procedures. Anesthesia and the stress of surgery can affect blood pressure and blood flow to the kidneys, and the continuous measurement of urine output provides real-time information about a patient’s circulatory and renal health. This data allows the anesthesia team to precisely manage intravenous fluid administration and blood product transfusion.
The catheter also manages urine output when a patient is unconscious or immobile for a significant period. It ensures the continuous, sterile collection of urine into a closed drainage system. This prevents skin breakdown and contamination of surgical wounds, allowing the patient to remain safely positioned during the procedure and immediate recovery phase.
Managing Post-Surgical Catheter Concerns
For most patients, the indwelling catheter is a temporary measure, often removed within 24 to 48 hours after the operation, sometimes even before leaving the operating room. Early removal is a priority due to the risk of a Catheter-Associated Urinary Tract Infection (CAUTI). This risk increases daily, as the catheter provides a pathway for bacteria to enter the bladder.
During the removal process, the small balloon holding the catheter in place is gently deflated, and the tube is withdrawn. Patients may experience a temporary stinging or burning sensation during their first few times urinating afterward, which is a common effect of the urethra being irritated by the catheter. Drinking plenty of water is recommended to help flush the urinary tract and ease discomfort.
The medical team monitors the patient after removal to ensure they can empty their bladder successfully. Some patients, particularly after pelvic or prolonged surgeries, may experience temporary urinary retention (the inability to fully empty the bladder). If this occurs, a bladder scanner is used to measure the remaining urine volume, and a temporary, one-time catheterization may be required to relieve the retention.