What are the indications for initiating hemodialysis in a patient with leptospirosis‑induced acute kidney injury?

Hemodialysis Indications in Leptospirosis-Induced Acute Kidney Injury

In patients with leptospirosis and Stage 3 AKI, initiate hemodialysis only for absolute life-threatening indications (severe hyperkalemia with ECG changes, refractory pulmonary edema, severe metabolic acidosis, or uremic complications), and avoid early "prophylactic" dialysis as it may worsen outcomes including mortality and chronic kidney disease development. 1

Absolute Indications for Dialysis Initiation

Initiate hemodialysis emergently when any of the following life-threatening complications occur:

• Severe hyperkalemia (>6.0 mmol/L) with ECG changes including peaked T waves, widened QRS complex, loss of P waves, or bradycardia 2, 3
• Refractory pulmonary edema causing respiratory compromise despite diuretic therapy, particularly critical in leptospirosis given the high risk of diffuse alveolar hemorrhage 2, 4
• Severe metabolic acidosis with impaired respiratory compensation 2, 3
• Uremic complications including encephalopathy, pericarditis, or bleeding diathesis 2, 3
• Severe fluid overload unresponsive to conservative management that threatens respiratory function 3

Critical Evidence Against Early Dialysis in Leptospirosis

A 2025 propensity-weighted study of 295 leptospirosis patients with Stage 3 AKI found that early RRT initiation (within 48 hours) was associated with significantly worse outcomes compared to delayed initiation. 1 The early dialysis group had:

• 2.08-fold increased odds of the composite outcome of death or new/worsening chronic kidney disease at one year (95% CI: 1.01-4.26, p=0.046) 1
• 2.74-fold increased odds of developing chronic kidney disease specifically (95% CI: 1.25-6.0, p=0.012) 1
• In the delayed group, only 25% eventually required dialysis, suggesting most patients can be managed conservatively 1

This finding is particularly important because it contradicts older observational data and represents the highest quality recent evidence specific to leptospirosis.

When to Delay Dialysis Safely

In leptospirosis patients with plasma creatinine <600 μmol/L (~6.8 mg/dL) and urinary indices suggesting pre-renal azotemia rather than established acute tubular necrosis, dialysis decisions can safely be delayed 48-72 hours while assessing response to rehydration. 5

Useful diagnostic indices to distinguish pre-renal azotemia from established AKI:

• Urine-to-plasma urea ratio shows high sensitivity and specificity 5
• Urine-to-plasma osmolar ratio helps differentiate pre-renal from intrinsic renal failure 5

Dialysis Prescription When Indicated

For Hemodynamically Stable Patients:

• Intermittent hemodialysis is preferred for rapid correction of severe hyperkalemia 2, 3
• Daily hemodialysis sessions are recommended for critically ill leptospirosis patients rather than alternate-day schedules 6, 4, 7
• A 2007 study comparing alternate-day versus daily dialysis in Weil's disease showed mortality reduction from 66.7% to 16.7% with daily treatment 6
• Target Kt/V of at least 1.2 per treatment, three times weekly minimum 2, 3

For Hemodynamically Unstable Patients:

• Continuous renal replacement therapy (CRRT) is mandatory for patients requiring vasopressor support 8, 2, 3
• Prescribe effluent dose of 20-25 mL/kg/hour 2, 3
• Use bicarbonate-based replacement fluids 9, 3
• Regional citrate anticoagulation is preferred if no contraindications 2, 3

Leptospirosis-Specific Considerations

Leptospirosis-induced AKI has unique features that influence dialysis management:

• Typically nonoliguric and hypokalemic due to tubular dysfunction with increased distal potassium secretion 4, 7
• High risk of pulmonary hemorrhage and ARDS necessitates strict fluid restriction and low daily net fluid intake 4, 7
• Interstitial nephritis is the principal pathology rather than pure acute tubular necrosis, which may explain better recovery potential with conservative management 4
• Tubular function abnormalities precede GFR decline, explaining the frequent hypokalemia 4, 7

Vascular Access

• Use uncuffed non-tunneled dialysis catheter for acute situations 2, 9
• Preferred site: right internal jugular vein, followed by femoral vein, left internal jugular vein, then subclavian vein (last choice due to stenosis risk) 2, 9
• Always use ultrasound guidance for insertion 9

Common Pitfalls to Avoid

Do not initiate "prophylactic" or early dialysis based solely on elevated BUN/creatinine values in leptospirosis patients without life-threatening complications. 1 The 2025 emulated trial provides strong evidence that this approach worsens outcomes, likely by:

• Exposing patients to dialysis-related complications unnecessarily
• Potentially interfering with natural renal recovery mechanisms
• Increasing risk of chronic kidney disease development

Avoid alternate-day hemodialysis schedules in critically ill leptospirosis patients - daily dialysis significantly reduces mortality in this population. 6, 4, 7

Maintain strict fluid restriction even when initiating dialysis, as leptospirosis patients have exceptionally high risk of pulmonary hemorrhage and ARDS. 4, 7