Foley catheters are the most commonly placed urethral catheters. A Foley catheter is a dual lumen tube that contains an inflatable cuff near the distal end (Figure 142-3). The distal end has two holes for urine to enter the catheter. Urine traverses the large inner lumen of the catheter to exit the proximal port. The second lumen is extremely small and allows air or fluid to flow into the inflatable cuff. The proximal end contains two ports. One port allows the egress of urine from the catheter. The second port is an inflation port. An air-filled or saline-filled syringe attaches to this port and is used to inflate the cuff. When inflated, the cuff prevents the distal end of the catheter from slipping out of the bladder.
Commonly used urethral catheters. A. Illustration of the Foley catheter (left) and the Coudé catheter (right). B. Photograph of the distal ends of the Foley catheter (left) and the Coudé catheter (right).
Foley catheters come in a variety of sizes and styles. A 14 or 16 French catheter is the size most commonly used in adolescent or adult patients. The two-way catheter is most commonly used. It is designed for urinary drainage and described in the preceding paragraph. It is a dual lumen tube with a small lumen to inflate the cuff and a large lumen to drain urine from the bladder. Three-way catheters are employed when bladder irrigation, in addition to urinary drainage, is required. These catheters have a small lumen to inflate the cuff, an intermediate-sized lumen to instill irrigation solution, and a large lumen to drain urine from the bladder. In the Emergency Department, they are placed in patients with gross hematuria and the passage of blood clots that may or have caused an acute urinary retention.
Clean and prep the penis, anesthetize the urethra, and set up a sterile field as mentioned previously. Select an appropriately sized Foley catheter. Inflate the cuff to check its integrity. Deflate the cuff. Grasp the penis with the nondominant hand. Pull the penis taut and upright to straighten out the penile urethra (Figure 142-4A). Retract the foreskin if the patient is uncircumcised. Do not forget to reduce the foreskin after inserting the catheter to prevent the formation if a paraphimosis. Grasp the Foley catheter with the dominant hand. Dip the tip of the catheter in, or an assistant can apply, water-soluble lubricant or anesthetic jelly (Figure 142-4A). Insert the catheter into the penile urethra via the meatus. Continue to gently but firmly advance the Foley catheter into the urethra until the proximal ports are at the urethral meatus (Figure 142-4B). This ensures that the distal tip of the catheter and the cuff will reside within the bladder (Figure 142-4C). If the distal end of the catheter is not completely within the bladder, inflation of the cuff inside the urethra will result in severe pain, hematuria, and possible urethral rupture.
Foley catheter insertion. A. The lubricated catheter is inserted into the urethra. B. The catheter is advanced until the ports are at the meatus. C. Cross section of the male pelvis showing the distal catheter positioned within the bladder. D. Urine aspiration confirms proper placement of the catheter. E. The cuff at the tip of the catheter is inflated. F. The catheter is gently withdrawn to lodge the cuff against the bladder neck.
Urine should begin to spontaneously flow out of the large port. Insert the proximal end of the catheter into a sterile container to collect the urine. If urine does not spontaneously flow out of the large port, attach a 60 mL syringe to the port and aspirate urine to confirm proper placement of the catheter (Figure 142-4D). Consider using transabdominal ultrasonography to confirm proper catheter placement and the presence of urine within the bladder. If no urine is aspirated and/or ultrasound imaging does not confirm appropriate placement, remove the catheter from the urethra and reattempt the procedure.
Attach an air-filled or saline-filled syringe to the cuff inflation port (Figure 142-4E). Inject the air or saline to inflate the cuff (Figure 142-4E). Inject only the volume of air or sterile saline recommended by the catheter manufacturer. This can be found on the catheter package and is often printed on the cuff inflation port. Remove the syringe from the cuff inflation port. Gently withdraw the Foley catheter until resistance is met. This signifies that the cuff is lodged against the bladder neck (Figure 142-4F). Attach an adapter and urine collection system to the urine port of the Foley catheter. Reduce the foreskin if present and it was retracted to insert the catheter.
Secure the catheter. Wrap tape around the urine port of the Foley catheter and continue it onto the adapter and first 3 to 5 cm of the collection tubing. This will prevent the system from disconnecting. Tape the collection tubing to the patient's thigh to prevent it from pulling out the adapter or the Foley catheter when the patient moves. Some authors also secure the Foley catheter as it exits the penile urethra (Figure 142-5).5 This is especially important if a red rubber catheter or uncuffed coudé catheter is used as these cuffless catheters are not self-retaining. Place three thin strips of tape along the length of the penis and attached to the Foley catheter. Benzoin solution can be applied to the penis to aid in adhesion of the tape. Place a piece of tape circumferentially around the tape ends attached to the catheter. Never apply tape circumferentially around the penis as it may cause ischemia.
A method to secure the urethral catheter as it exits the penis.5
Difficult Urethral Catheterization
Difficulty is commonly encountered when inserting a urethral catheter. Urethral pathology (e.g., valves, strictures, narrowing, or folds) or prostate enlargement can often be overcome by switching from a Foley to a coudé catheter and the application of digital assistance. If unsuccessful, the use of filiforms and followers can often be used to successfully insert the catheter. Foreskin edema from anasarca, pelvic lymphatic blockage, a paraphimosis, or penile trauma can often cover the glans penis and urethral meatus. Attempt to reduce the edema manually or with an elastic bandage (Chapter 148). Significant edema may require penile anesthesia and needle decompression (Chapter 148) or a dorsal slit of the foreskin (Chapter 150). A phimosis may be physiologic in children or acquired and the result of scarring in adults from repeated bouts of inflammation, infections, or sexually transmitted diseases. A phimosis may require a dorsal slit of the foreskin (Chapter 150) to allow for urethral catheterization or a dilation of the phimotic opening.
A relatively new device is the DirectVision™ microendoscope (PercuVision, Gahanna, OH). This consists of a rolling cart, fiberoptic endoscopic bundle, and tri-lumen silicone catheter. The cart houses a color monitor and the fiberoptic light source. A disposable fiberoptic bundle attaches to the light source and is inserted through the tri-lumen catheter. The fiberoptic bundle transmits light to the tip of the catheter and images back to the monitor. The system allows visually guided urethral catheterization in the male patient. It may decrease urinary tract trauma during catheterization, improve catheterization success rates, and simplify the catheterization process. At the time of this publication, this product cannot be recommended for routine urethral catheterization due to the initial expense of the system, the costs of the single-use disposable endoscopic bundles and catheters, and little clinical literature regarding its use in the Emergency Department. This device may be commonly used in the future as costs decrease and clinical information becomes more readily available.
The coudé catheter is similar to a Foley catheter except that the distal end is curved and the tip has a small rounded ball (Figure 142-3). The catheter was designed to bypass the areas of the urethra that a straight catheter could not negotiate. A coudé catheter may be used if a Foley catheter cannot be passed into the bladder. It may also be used if the patient has a known urethral stricture, urethral valve, narrow urethra, or enlarged prostate.
The coudé catheter comes in various sizes and styles. Some models contain a cuff while others do not. The catheter is inserted into the urethra with the elbow on the tip of the catheter facing anteriorly. The procedure for placement of the catheter into the bladder is the same as that for a Foley catheter.
Occasionally, the Foley or coudé catheter tip will become caught in a posterior fold of the urethra just distal to the urogenital diaphragm (Figure 142-6A). Place the fingers of the nondominant hand on the perineum between the scrotum and anus (Figure 142-6B). Apply upward pressure on the perineum to direct the catheter tip upward while simultaneously advancing the catheter with the dominant hand through the urogenital diaphragm and into the bladder. An assistant is often required to hold and stabilize the penis while the Emergency Physician uses their hands to manipulate the catheter and perineum.
Digital assistance. A. The Foley catheter is caught in a posterior urethral fold. B. Digital upward pressure on the perineum will direct the catheter tip upward and through the urogenital diaphragm.
If the patient has an enlarged prostate, the bladder neck is often elevated superiorly and anteriorly. Digital assistance on the skin of the perineum may be unsuccessful. A finger in the rectum may be used to move the catheter tip anteriorly so that it can be advanced into the bladder.
Filiform and Follower Catheters
In patients with severe urethral strictures or urethral folds, it may be impossible to pass a Foley catheter or a coudé catheter. The next step in the progression to catheterize the bladder is to use filiform and follower catheters. Filiforms are very narrow, flexible, and solid catheters. Their sole function is to successfully negotiate a strictured urethral segment and enter the bladder. The distal end of the filiform catheter may be straight or pig-tailed and are available in a variety of sizes (Figure 142-7A). The proximal end of the filiform catheter is a standard size and contains a metal female connector (Figure 142-7B). The followers are flexible, hollow catheters that attach to the filiform catheters. The distal end of the follower catheter contains a metal male connector, to attach to the proximal end of the filiform catheter, and a hole to allow urine to enter the catheter (Figure 142-7C). The follower catheters come in a variety of sizes and allow the physician to dilate the urethra and catheterize the bladder. The proximal end of the follower catheter is open and accepts a Christmas tree adaptor (Figure 142-7D).
Photographs of the ends of the filiform and follower catheters. A. Distal ends of the filiform catheter. B. Proximal ends of the filiform catheter. C. Distal ends of the follower catheter. D. Proximal ends of the follower catheter.
A filiform and follower should be used only after unsuccessful catheterization attempts with a Foley catheter and a coudé catheter. The patient has already been prepped and draped for the prior catheterization attempts. Reinstill anesthetic jelly into the urethra to ensure adequate anesthesia. Numerous sizes and shapes of filiform and follower catheters should be available at the bedside. An assistant will be required to open each sterile packet and hand the filiforms and followers to the Emergency Physician as needed.
Grasp the cleaned, prepped, and anesthetized penis with the nondominant hand. Pull the penis taut and upright to straighten out the penile urethra (Figure 142-8A). Grasp a filiform catheter and dip the tip in water-soluble lubricant or anesthetic jelly. Gently insert and advance the filiform catheter into the urethra with a twisting motion (Figure 142-8A). Stop advancing the filiform catheter when resistance is met (Figure 142-9A). Insert a second well-lubricated filiform catheter into the urethra with a twisting motion until it meets resistance (Figure 142-9B). Gently attempt to advance the first filiform catheter. If it will not advance, insert a third filiform catheter (Figure 142-9C). Continue to insert filiform catheters and gently manipulate the previously inserted filiform catheters (Figure 142-8B). Continue this process until one filiform catheter advances into the bladder so that its proximal end is 2 cm from the tip of the penis (Figure 142-9C). Remove all the filiform catheters except the one that entered the bladder (Figure 142-9D).
Insertion of the filiform catheters. A. The catheter is inserted and advanced into the urethra (straight arrow) with a twisting motion (curved arrows). B. Additional catheters are inserted until one advances into the bladder. The numbers represent the order of insertion of the filiform catheters.
Midsagittal section of the penis demonstrating insertion of the filiform catheter. A. The filiform catheter is inserted until resistance is encountered. B. A second filiform catheter is inserted until it encounters resistance. C. A third filiform catheter is inserted and advances into the bladder. D. Filiform catheters #1 and #2 have been removed.
Choose a follower catheter to insert into the bladder. Liberally lubricate the tip of the follower catheter and attach it to the filiform catheter (Figure 142-10A). Gently advance the follower catheter until its proximal end is 3 to 4 cm from the tip of the penis (Figure 142-10B). If the follower catheter meets resistance during its advancement, do not force it into the urethra. Instead, withdraw the follower catheter until the tip is 2 to 3 cm outside the penis. Remove the follower catheter from the filiform catheter. Attach a well-lubricated follower catheter onto the filiform catheter that is 1 or 2 French smaller and attempt to advance it into the bladder. Continue this process until a follower catheter can be completely advanced into the bladder. The filiform catheter will be completely curled up inside the bladder (Figure 142-10B).
Insertion of the follower catheter. The filiform catheter has been previously inserted into the bladder. A. The follower catheter is screwed into the filiform catheter. B. The follower catheter is advanced into the bladder. C. Urine aspiration confirms proper placement.
Urine should spontaneously flow from the properly positioned follower catheter. If not, attach a 60 mL syringe and Christmas tree adaptor to the follower catheter (Figure 142-10C). Apply negative pressure to the syringe to aspirate urine and confirm the proper placement of the tip of the follower catheter. Attach a urinary collection system to the follower catheter and secure the catheter as described previously.
The patient with urinary obstruction cannot be discharged home with a filiform and follower inserted inside the bladder. If the follower catheter is a size 16 or 18 French, completely withdraw it and the filiform catheter and insert a 16 French Foley catheter. If the follower catheter is smaller than size 16 French, the urethra must be dilated. Withdraw the follower catheter until the distal tip is 2 to 3 cm outside the penis. Remove the follower catheter from the filiform catheter. Attach a well-lubricated follower catheter onto the filiform catheter that is 1 or 2 French larger than the previous one and gently advance it into the bladder. Continue this process until a follower catheter that is size 16 French easily passes into the bladder. Remove the filiform and follower catheters. Insert a size 16 French Foley catheter. Secure the catheter as described previously.