A urinary catheter is a flexible, hollow tube inserted into the bladder to drain urine when natural voiding is compromised. Because catheterization bypasses the body’s natural protective barriers, it carries a significant risk of introducing infection or causing injury to the urethra. This article is informational guidance for understanding the steps involved and reinforces that insertion must be performed by a fully trained healthcare professional, such as a nurse or physician, to minimize potential harm.
Medical Context and Types of Urinary Catheters
The primary need for urinary catheterization arises from an inability to empty the bladder, or urinary retention. Catheters are also used to monitor precise urine output in critically ill patients, manage incontinence when other methods have failed, and drain the bladder during or after surgical procedures. The choice of catheter depends on the specific medical necessity and the anticipated duration of use.
The two main categories are indwelling and intermittent catheters. Indwelling catheters, often called Foley catheters, are designed to remain in the bladder for an extended period, continuously draining urine into an external collection bag. They are held in place by a small balloon inflated with sterile water once the catheter tip is positioned inside the bladder.
Intermittent catheters, also known as straight or “in-and-out” catheters, are used for temporary drainage. They are inserted only long enough to empty the bladder, then immediately removed. This method is often preferred for individuals capable of self-catheterization, as it may reduce the risk of long-term infection. A less common alternative, the suprapubic catheter, is surgically placed directly into the bladder through the abdominal wall, bypassing the urethra entirely.
Essential Preparation and Sterility Protocols
Maintaining a strict aseptic technique is essential for preventing a Catheter-Associated Urinary Tract Infection (CAUTI). Preparation begins with meticulous hand hygiene, followed by establishing a sterile field using drapes from the catheterization kit. All necessary supplies, including the catheter, sterile gloves, lubricant, and antiseptic solution, must be organized before touching the patient.
The patient must be positioned to allow for maximum visualization and comfort while maintaining privacy. A female patient is typically placed on her back with her knees flexed and hips rotated outward. A male patient is positioned supine with legs extended and slightly apart to expose the genital area.
The urethral opening, or meatus, must be thoroughly cleaned with an antiseptic solution. For a female patient, the labia are separated with the non-dominant hand, and cleansing swabs are passed in a single downward stroke from front to back, using a fresh swab for each pass. For a male patient, the penis is grasped with the non-dominant hand, and the meatus is cleaned in a circular motion, working outward.
A water-soluble lubricant is applied to the catheter tip to ease passage and reduce friction. In male catheterization, a syringe pre-filled with lidocaine gel is often instilled directly into the urethra for local anesthesia and lubrication. A dwell time of five to ten minutes is necessary for the numbing effect to take hold.
Detailed Insertion Procedure
The catheter tip must be handled only by the sterile, gloved dominant hand to prevent contamination. For both sexes, the patient should be encouraged to take slow, deep breaths, which helps relax the sphincter muscles and facilitate easier advancement. The lubricated tip is gently advanced into the meatus.
In a female patient, the urethra is relatively short. The catheter is advanced until urine flow is observed, which typically occurs after insertion of about 5 to 7.5 centimeters. Once urine appears, the catheter must be advanced an additional 2.5 to 5 centimeters (1 to 2 inches) to ensure the balloon port is fully within the bladder cavity.
Male catheterization is complex due to the length and curves of the urethra. The penis is held perpendicular to the body to straighten the first curve. The catheter is advanced slowly; if resistance is met, pause insertion while maintaining gentle, constant pressure.
The catheter must be advanced almost to the Y-junction, or approximately 17 to 22.5 centimeters, to ensure it is fully inside the bladder. Only after urine flow is confirmed should the retention balloon be inflated with the designated volume of sterile water. Following inflation, the catheter is gently retracted until resistance is felt, confirming the balloon is resting against the bladder neck to secure the device.
Post-Insertion Care and Recognizing Complications
Proper maintenance is required to ensure function and prevent infection. The catheter tubing must be secured to the patient’s inner thigh or lower abdomen using a securement device to prevent movement and traction on the urethra. The drainage bag must always be positioned below the level of the bladder to facilitate gravity drainage.
The drainage bag should be emptied regularly, typically when it reaches one-half to two-thirds of its capacity, and at least every four to eight hours. Daily hygiene involves cleaning the meatus and the portion of the catheter tube exiting the body with mild soap and water.
Infection is the most common complication. Signs of a potential CAUTI include fever or chills, cloudy or foul-smelling urine, and pain in the lower back or abdomen. Leakage around the catheter, known as bypassing, may signal a blockage in the tubing or a bladder spasm. Absence of urine output suggests a serious blockage requiring immediate professional attention.
For removal, the retention balloon must be fully deflated by inserting a syringe into the balloon port and allowing the sterile water to drain out passively. It is imperative that the entire volume of fluid used for inflation is withdrawn before removal is attempted. The catheter is then removed with a slow, continuous, gentle pull, often advising the patient to exhale during the movement to help relax the area.