What is the target urine output for resuscitation in adults?

Target Urine Output for Resuscitation in Adults

The target urine output for resuscitation in adults is ≥0.5 mL/kg/hour, which is a well-established standard across multiple critical care guidelines.

Evidence-Based Rationale

Multiple high-quality guidelines consistently recommend maintaining a urine output of at least 0.5 mL/kg/hour during resuscitation:

• The 2020 World Journal of Emergency Surgery guidelines for perforated peptic ulcer management strongly recommend "restoring physiological parameters with a mean arterial pressure ≥ 65 mmHg, a urine output ≥ 0.5 ml/kg/h, and a lactate normalization" 1

• The 2017 Surviving Sepsis Campaign guidelines maintain this target, listing urine output ≥ 0.5 mL/kg/hour as one of the key resuscitation parameters 1

• The 2017 World Society of Emergency Surgery guidelines for intra-abdominal infections also reference this target as part of standard resuscitation protocols 1

• For burn patients, the 2020 Anaesthesia guidelines similarly recommend targeting a urine output of 0.5–1 mL/kg/hour 1

Clinical Application

Monitoring Protocol

1. Measure hourly urine output
2. Calculate based on patient's weight (mL/kg/hour)
3. Maintain output at or above 0.5 mL/kg/hour
4. Document trends over time, not just isolated measurements

Integration with Other Parameters

The target urine output should be used alongside other resuscitation targets:

• Mean arterial pressure ≥ 65 mmHg
• Normalization of lactate levels
• Appropriate heart rate and capillary refill
• Central venous oxygen saturation goals when applicable

Important Considerations

Limitations of Urine Output as a Marker

Urine output is an indirect marker of renal perfusion and may be affected by:

• Pre-existing renal disease
• Medications (especially diuretics)
• Neurohormonal factors that can influence diuresis independent of volume status 2

Special Populations

• Burn patients: The target remains 0.5-1 mL/kg/hour, though fluid requirements may be significantly higher 1, 3
• Surgical patients: While some research suggests lower targets (0.2 mL/kg/hour) might be safe in select low-risk surgical patients 4, the standard 0.5 mL/kg/hour remains recommended for resuscitation in critically ill patients

Prognostic Value

Lower urine output (<0.5 mL/kg/hour) is associated with:

• Higher in-hospital mortality
• Worse neurological outcomes in post-cardiac arrest patients 5
• Increased risk of acute kidney injury

Avoiding Common Pitfalls

1. Over-resuscitation: Targeting excessive urine output (>1 mL/kg/hour) can lead to fluid overload, which is associated with complications including pulmonary edema and abdominal compartment syndrome 1

2. Under-resuscitation: Persistent oliguria despite fluid administration may indicate:

   • Inadequate resuscitation
   • Renal dysfunction
   • Need for additional hemodynamic monitoring or vasopressor support

3. Isolated focus: Urine output should never be the sole parameter guiding resuscitation but should be integrated with other clinical and laboratory markers

4. Delayed response: Urine output may lag behind other markers of adequate resuscitation, requiring patience and continued monitoring

In summary, while individual patient factors may necessitate adjustments, the evidence-based target for urine output during resuscitation in adults remains ≥0.5 mL/kg/hour, as consistently recommended across multiple critical care guidelines.