What is Postoperative Urinary Retention?
Postoperative urinary retention (POUR) is a condition where a person is unable to urinate after surgery, even though their bladder is full. This issue can cause significant discomfort to the patient, or it might go unnoticed. It can often be quickly solved with minor medical interventions, but in some cases, it may have long-term effects on the patient’s health. Studies have shown that this issue can occur in anywhere from 5% to 70% of patients after surgery, making it a fairly common issue to encounter in hospitals, urgent care centers, or doctor’s offices after a surgical procedure. The ability to identify and treat POUR is crucial for any medical provider who is caring for a patient after surgery.
What Causes Postoperative Urinary Retention?
Normal bladder function allows you to control urination and is governed by two nervous systems: the somatic and the autonomic. When the bladder is filling up, a part of the autonomic system coming from the middle of the spine relaxes the bladder muscle and tightens the bladder base, neck, and tube that carries urine out of the body.
When you need to urinate, another part of the autonomic system coming from the lower part of your spine activates the bladder muscle, and relaxes the tube carrying out urine. At the same time, the somatic or voluntary nervous system relaxes the external muscle controlling urine flow, which allows you to control urination.
Surgery can complicate this urination process, which can cause difficulty in releasing urine after surgery. Factors such as anesthesia, medications, pain, changes because of surgery, and tissue damage, can all affect a patient’s urine release, particularly influencing the autonomic nervous system which controls the process.
Anesthesia can have an impact on normal urination. All forms of anesthesia can lead to difficulties in releasing urine by suppressing the controls and reflexes for urination, both in the brain and the peripheral nerves by blocking nerve signals in the lower part of the spinal cord. General anesthetics relax the bladder muscle and interfere with the bladder’s autonomic regulation. This has been shown in the increase in bladder capacity under general anesthesia. Spinal and epidural anesthetics affect urination in a different way by interfering with the nerves controlling urination as they go in and out of the spinal cord and reach the brain.
Medications taken during and after surgery can also lead to difficulties in releasing urine. Specifically, opioids can decrease the feeling of a full bladder by lowering the activity of nerves servicing the bladder and increase the tightness of the tube carrying out urine, leading to an obstruction.
Surgical pain can also stimulate the autonomic nervous system, typically associated with the “fight or flight” response, leading to the relaxation of the bladder muscle and contraction of the tube carrying out urine, making the bladder constantly feel like it’s in the filling stage.
Lastly, any disruption of vital structures needed for urination due to surgery can lead to difficulties in releasing urine. Pelvic surgeries are particularly risky as they can affect the autonomic nervous system and nerve clusters in the pelvis. It’s why there is a strong emphasis on surgical procedures that aim to preserve nerves when possible.
Risk Factors and Frequency for Postoperative Urinary Retention
Postoperative urinary retention, or POUR, is a condition that can occur after surgery, which can make it difficult to urinate. The reported occurrence of POUR varies widely, anywhere from 5% to 70%, due to differences in how POUR is defined from study to study. Various factors can impact the likelihood of experiencing POUR, including the type of surgery, the kind of anesthetic used, the length of the surgery, and individual patient factors like existing health conditions, age, gender, and preoperative urinary function. This makes it difficult to predict a single rate of POUR occurrence for all patients.
- About 3.8% of patients undergoing outpatient general surgery procedures will develop POUR.
- For patients undergoing outpatient orthopedic procedures, the rate of POUR can range from 10% to 84%.
- Following colorectal surgery, the occurrence of POUR can be anywhere between 1% and 52%.
- POUR can occur in 5.9% to 38% of cases following herniorrhaphy (hernia repair surgery).
Signs and Symptoms of Postoperative Urinary Retention
Postoperative urinary retention is a complication that can occur after a surgical procedure. The main indicators include a painful or uncomfortable sensation in the lower abdomen, spasms in the bladder, or leakage of urine combined with an inability to urinate. However, anesthesia or sedation from the surgery may mask these symptoms. Keep in mind that more than 60% of patients who have undergone outpatient surgery do not report these symptoms, even though their bladder may be overfilled. It’s crucial to monitor how long it has been since a patient used the bathroom post-surgery – most patients should not go more than 6 to 7 hours without urinating.
During a physical check-up, the lower abdomen is usually examined for signs of bladder fullness. This may present as a firm feeling in the lower abdomen upon touch and a dull sound when lightly tapped. The average bladder can hold 400 to 600 mL of urine. Dullness up to the belly button may indicate a volume of roughly 500 mL, while dullness extending beyond it may suggest the bladder contains as much as 1000 mL. However, keep in mind that physical exams can sometimes overestimate bladder volume.
Testing for Postoperative Urinary Retention
In a hospital setting, if a patient is having trouble urinating after surgery, doctors often use ultrasound or a machine called a bladder scanner to examine the urinary tract. Like a physical examination, these tools help doctors understand what’s going wrong inside the body. In fact, research has shown that the measurements taken by ultrasound are quite accurate when compared with those from a procedure called catheterization.
Further, if the doctor worries that the patient had some sort of urinary problem before the surgery and didn’t order blood tests beforehand, they might order tests now. These tests could include a basic metabolic panel (BMP) or a blood test to measure a substance called creatinine. High levels of creatinine in the blood can be a sign of kidney disease, potentially caused by long-term urinary issues.
Treatment Options for Postoperative Urinary Retention
When someone is recovering from surgery, one complication they might face is having trouble emptying their bladder, a condition called postoperative urinary retention. The best way to deal with this problem is to prevent it from happening in the first place. It’s important for the entire care team to identify if a patient has factors that make them more likely to experience this problem, and mitigate them if possible.
Before surgery, the care team looks at certain risk factors to understand who is more likely to experience urinary retention. Some of these factors include age, gender, existing health conditions, and the type of surgery being performed. Men are nearly twice as likely as women to experience this problem. People over the age of 50 are also at higher risk. Certain health conditions like kidney disease, diabetes, and psychiatric conditions like depression can also increase the risk. In addition, people with prostate problems may be more likely to have urinary retention. Patients who will have surgery on their knee, hip, or colon are also more at risk. Some medications, such as alpha-blockers, can actually protect against urinary retention if they’re taken before surgery.
During surgery, factors like how long the operation lasts, the volume of intravenous fluids given, and the type of anesthetic can influence the chances of experiencing urinary retention. If surgery lasts longer than two hours or a high volume of fluids is given, urinary retention might be more likely.
After surgery, the risk of urinary retention can go up if a patient doesn’t start moving around relatively quickly or if they’re given opioid medications for pain management. These medications can interfere with the messages being sent to the bladder about when it needs to empty. In general, the more opioids a patient takes, the greater their risk of urinary retention.
If urinary retention does occur after surgery, the bladder will need to be drained. This can be achieved through the placement of a catheter. There’s some debate as to whether a permanent catheter should be inserted or if temporary catheterizations are better. The patient might also be prescribed an alpha-blocker to help improve urine flow. The catheter can usually be removed after 1 to 3 days after catheterization. And if a patient continues to have trouble urinating after 72 hours, they might need to see a urologist for further assessment.
What else can Postoperative Urinary Retention be?
If a patient who has recently had surgery is experiencing abdominal pain and can’t urinate, several issues could be contributing to these symptoms. Here are some possible causes:
- Lack of enough fluids in the body coupled with pain from surgery: A bladder test checking for fullness should confirm or rule out this condition.
- An accidental injury to both ureters (tubes carrying urine from the kidneys to the bladder) during surgery, or a similar injury affecting a single kidney in patients who only have one kidney: A bladder test checking for fullness should confirm or rule out this concern.
- An accidental injury to the bladder during surgery: A bladder test checking for fullness should confirm or rule out this possibility.
These reasons emphasize the need for a bladder test to determine the real cause of the patient’s symptoms.
What to expect with Postoperative Urinary Retention
POUR, or postoperative urinary retention, can develop due to several factors. These can include pain, difficulty in walking, or certain medications. Usually, once these issues are addressed and improved, POUR goes away. On top of that, the damage to the bladder muscles from acute retention is often reversible with drainage and rest for your bladder.
The typical treatment involves draining the bladder, starting medication that helps relax the bladder muscles (called alpha-blockers), and waiting for some time after a surgical operation. Most patients can start peeing normally again after a “trial without a catheter” 1 to 3 days after the catheter is placed.
However, there are two exceptions to this rule: patients who had surgery involving nerves in the pelvis that are critical for urination and patients who had severe, unidentified urinary problems before the surgery.
For patients whose surgery involved pelvic nerves, the prognosis will depend on how much damage was caused to the nervous system during surgery and has to be evaluated individually.
The prognosis for patients with unidentified urinary issues before surgery is more uncertain. Some factors associated with poor outcomes are being over 70 years old, having severe urinary symptoms before surgery, having had spinal surgery, kidney swelling or “hydronephrosis,” and having a bladder volume over 1000 millilitres at the time of placing the catheter.
Possible Complications When Diagnosed with Postoperative Urinary Retention
Developing POUR, or Postoperative Urinary Retention (a condition where patients are unable to urinate after surgery), can cause a lot of complications in the hospital.
- If POUR leads to acute retention, it can be highly painful, and the body’s natural response to this can cause other issues like vomiting, low or high blood pressure, or even heart rhythm problems, which can all potentially worsen the patient’s recovery after surgery.
- POUR might also result in urinary tract infection, either directly because the bladder is not emptying properly, or indirectly because of the continuous or intermittent use of catheters.
- If POUR is not diagnosed or is diagnosed late, it can lead to severe, prolonged bladder overdistension (a condition where the bladder has been stretched beyond its normal capacity) with changes to the muscle structure of the bladder. Typically, if bladder volumes of less than 1000 mL are diagnosed and treated within 2 hours, there’s not expected to be any harm.
- Lastly, having POUR has been shown to increase the length of hospital stays.
Preventing Postoperative Urinary Retention
Before a surgical operation, it’s important to educate patients who have a high risk of developing a problem called postoperative urinary retention (POUR). This is a condition where a patient has trouble urinating after surgery. It’s necessary to ensure patients know about this risk, so they aren’t unduly stressed if this complication arises after their operation.
If a patient does develop POUR, they should be comforted knowing that, in most cases, it’s temporary. Through the help of a process called catheterization, where a tube is inserted into the bladder to help urine flow, and given some time, most people return to normal urinating function. Long-term use of a catheter, medication, or more surgery to fix the problem is usually not required.
