From the Guidelines
Minimal urinary output after a C-section should not be managed with additional fluid therapy unless the cause is investigated and established, as oliguria is a normal physiological response during surgery and anesthesia. According to the most recent and highest quality study, oliguria should not trigger fluid therapy, and instead, the cause should be investigated prior to additional fluid therapy 1. The study recommends near zero fluid balance and avoiding the use of 0.9% saline due to the risk of salt and fluid overload.
Causes of Minimal Urinary Output
The causes of minimal urinary output after a C-section can be multifactorial, including:
- The effects of anesthesia on bladder function
- Pain medications like opioids that can suppress urination
- Fluid shifts during surgery
- Rarely, surgical complications affecting the urinary tract
Management of Minimal Urinary Output
The management of minimal urinary output after a C-section should focus on:
- Encouraging oral hydration, aiming for 2-3 liters of fluid daily unless otherwise instructed
- Avoiding the routine use of urinary catheters, as they can increase the incidence of urinary tract infections, urethral pain, and difficult voiding 1
- Early ambulation, when permitted by the doctor, to help restore normal bladder function by improving circulation and reducing pressure on the bladder
Key Recommendations
- Avoid additional fluid therapy unless the cause of oliguria is investigated and established 1
- Avoid the routine use of urinary catheters 1
- Encourage oral hydration and early ambulation to help restore normal bladder function and reduce the risk of complications.
From the Research
Minimal Urinary Output After C-Section
- Minimal urinary output after a C-section can be caused by various factors, including the use of oxytocin infusions, blood loss, and dehydration 2.
- A study found that the median urine output in the first 6 hours after elective C-section was 0.8 mL kg(-1)h(-1) in women receiving oxytocin, compared to 1.4 mL kg(-1)h(-1) in those who did not receive oxytocin 2.
- The use of oxytocin infusions can reduce urine output, which may be a direct effect or related to increased blood loss in this group 2.
- Another study found that delayed urinary catheter removal was associated with a higher incidence of urinary tract infections (UTI), delayed ambulation time, and longer hospital stay compared to early or intermediate removal groups 3.
- The optimal time for removal of a urinary catheter after C-section is still debated, but a systematic review and network meta-analysis suggested that removal 0-6 hours after C-section may be the optimal timing to prevent UTI, frequent urination, and reduce length of hospital stay 4.
Factors Affecting Urinary Output
- Oxytocin infusions: can reduce urine output 2
- Blood loss: can affect urine output 2
- Dehydration: can affect urine output 2
- Urinary catheter removal time: can affect the risk of UTI, urinary retention, and hospital stay 3, 4
Related Studies
- A study on the effect of ibuprofen on renal function in children found that short-term use of ibuprofen did not significantly increase the risk of impaired renal function 5.
- A study on the impact of serum acetaminophen concentration on changes in serum potassium, creatinine, and urea concentrations found that acetaminophen overdose can cause electrolyte disturbances, including reduced serum potassium concentrations and elevated serum creatinine concentrations 6.