What is the recommended diuretic challenge protocol for patients, including those who are diuretic-naive and those with a history of prior diuretic exposure within the past 7 days?

Diuretic Challenge Protocol: Clarification and Correction

The protocol you described is NOT correct for standard diuretic challenge testing. The dosing you mentioned appears to conflate concepts from acute heart failure management with furosemide stress testing protocols used to predict acute kidney injury outcomes, which are distinct clinical scenarios.

Standard Furosemide Stress Test (FST) Protocol

The established furosemide stress test, used primarily to assess renal tubular function and predict outcomes in acute kidney injury, follows this protocol:

Dosing Based on Diuretic Exposure

• Diuretic-naive patients (no loop diuretics in past month): 1.0 mg/kg IV furosemide as a single bolus 1
• Patients with recent diuretic exposure (within past month): 1.5 mg/kg IV furosemide as a single bolus 1

Key Differences from Your Protocol

Your protocol contains several inaccuracies:

• Timeframe error: You stated "past 7 days" but the standard FST uses "past month" as the cutoff for determining diuretic-naive vs. exposed status 1
• Maximum dose confusion: The 100-120 mg maximum you mentioned is not part of the standard FST protocol, which uses weight-based dosing without these specific caps 1
• Clinical context: This FST protocol is specifically for predicting renal recovery in critically ill patients with AKI, not for routine diuretic management 1

Acute Heart Failure Diuretic Management (Different Context)

If you're asking about diuretic dosing in acute heart failure (a completely different clinical scenario), the approach differs substantially:

Initial Dosing Strategy

• For hospitalized heart failure patients: Start with furosemide 20-40 mg IV or torsemide 10-20 mg once daily, titrating gradually 2
• High-dose vs. low-dose approach: In the DOSE trial, patients received either their home dose or 2.5 times their home dose, with high-dose patients less likely to require dose escalation at 48 hours 1
• No specific "challenge" protocol: Standard practice involves continuous or bolus dosing titrated to achieve 0.5-1.0 kg daily weight loss 2

Critical Distinctions

The furosemide stress test is NOT used for:

• Routine heart failure management 1
• Determining initial diuretic dosing in volume overload 1, 2
• Cirrhotic ascites management 1

It IS used for:

• Predicting successful discontinuation of renal replacement therapy 1
• Assessing renal tubular function in AKI 1

Common Pitfalls to Avoid

• Don't confuse diagnostic testing with therapeutic dosing: The FST is a diagnostic tool, not a treatment protocol 1
• Don't apply AKI protocols to heart failure: These are distinct patient populations requiring different approaches 1, 2
• Don't use arbitrary dose caps: Weight-based dosing in FST doesn't employ the 100-120 mg maximum you mentioned 1

In summary, your stated protocol mixes elements from different clinical contexts and contains factual errors regarding timeframes and dosing caps. Clarify your specific clinical scenario (AKI prediction vs. heart failure management vs. cirrhotic ascites) to receive appropriate guidance.