What medications can be given for severe hypoxemia and volume overload prior to dialysis?

Medications for Severe Hypoxemia and Volume Overload Prior to Dialysis

For severe hypoxemia and volume overload prior to dialysis, administer IV loop diuretics (furosemide) as bolus or continuous infusion to improve symptoms of congestion, supplemental oxygen to maintain SpO2 >90%, and consider IV vasodilators (nitrates or nitroprusside) if systolic blood pressure exceeds 110 mmHg. 1

Loop Diuretics for Volume Overload

IV loop diuretics are the cornerstone of acute management for volume overload prior to dialysis. 1, 2

• Administer furosemide as either bolus injections or continuous infusion, with preference for higher doses in patients with resistant fluid overload 1
• If poor response to initial IV loop diuretic bolus, consider continuous infusion or add a second diuretic agent (thiazide or mineralocorticoid receptor antagonist) for synergistic effect 1
• For resistant edema not responsive to increased loop diuretic doses, add acetazolamide in combination with thiazide or mineralocorticoid receptor antagonist 1
• Monitor for electrolyte depletion (hypokalemia, hyponatremia, hypochloremic alkalosis, hypomagnesemia, hypocalcemia) and check serum electrolytes, CO2, creatinine, and BUN frequently during initial therapy 3

Oxygen Therapy for Hypoxemia

Supplemental oxygen should be administered immediately if SpO2 <90% or PaO2 <60 mmHg, targeting SpO2 >90-94%. 1

• Oxygen therapy improves symptoms and reduces intradialytic hypotension risk, particularly in patients with cardiovascular or respiratory disease 1
• Consider supplemental oxygen administration even without hypoxemia in patients with severe volume overload and right ventricular dysfunction 4
• Use bicarbonate-containing dialysate rather than acetate-containing dialysate when dialysis is initiated, as acetate buffer causes hypoxemia through pharmacologic effects on lung function 5

Vasodilators for Severe Hypertension with Volume Overload

IV vasodilators are reasonable for symptomatic relief if systolic blood pressure exceeds 110 mmHg and volume overload is present. 1

• Consider IV nitrates or nitroprusside to relieve dyspnoea and reduce congestion when systolic blood pressure is >100-110 mmHg 1
• Vasodilators should be used as adjunct to diuretics, not as monotherapy, since volume overload underlies most hypertension in this population 1
• Avoid routine use of IV vasodilators in normotensive or hypotensive patients 1

Ventilatory Support for Severe Respiratory Distress

Non-invasive positive pressure ventilation should be considered if respiratory rate exceeds 25 breaths/minute and SpO2 remains <90% despite oxygen therapy. 1

• Non-invasive ventilation is indicated for severe dyspnoea with acidemia or respiratory failure persisting despite oxygen therapy 1
• Intubation and invasive ventilation should be considered only if progressive respiratory failure occurs despite non-invasive ventilation, or if reduced consciousness or physical exhaustion develops 1
• Caution: Positive pressure ventilation should be avoided if possible in patients with severe volume overload and right ventricular dysfunction, as it can worsen hemodynamics 4

Timing of Dialysis Initiation

Dialysis should be initiated urgently for persistent hyperkalemia, severe metabolic acidosis, volume overload unresponsive to diuretic therapy, or overt uremic symptoms. 1

• Dialysis may be initiated prophylactically before overt uremic symptoms develop in response to severe progressive hyperphosphatemia (>6 mg/dL) or severe symptomatic hypocalcemia 1
• Continuous renal replacement therapy (CRRT) is preferred over intermittent hemodialysis in hemodynamically unstable patients with pulmonary edema, as CRRT provides better hemodynamic stability and fluid balance control 1
• Frequent (daily) dialysis treatments are recommended considering the continuous metabolic derangements in acute kidney injury 1

Antihypertensive Medication Management

Continue cardioprotective antihypertensive medications (ACE inhibitors, ARBs, beta-blockers) unless they interfere with achieving euvolemia or cause intradialytic hypotension. 1, 6

• Prioritize non-pharmacologic volume control strategies (sodium restriction, ultrafiltration optimization) before escalating antihypertensive medications, as volume overload underlies most hypertension in dialysis patients 1
• Avoid nondialyzable beta-blockers (carvedilol) in patients at risk for intradialytic hypotension; consider highly dialyzable agents (metoprolol, atenolol) instead 1, 7
• If blood pressure is well controlled and antihypertensive medications interfere with ultrafiltration, reducing medications to allow enhanced ultrafiltration is reasonable 1

Common Pitfalls and Caveats

• Avoid excessive diuresis: Overly aggressive diuresis may cause dehydration, circulatory collapse, vascular thrombosis, and electrolyte depletion, particularly in elderly patients 3
• Monitor for hyponatremia: In severely hyponatremic patients requiring dialysis, use dialysate sodium concentration of 130 mEq/L and limit blood flow to 50 mL/minute to avoid raising serum sodium too quickly (maximum 2 mEq/L/hour) and prevent osmotic demyelination syndrome 8
• Reassess dry weight: In patients with recurrent hypotension, an inappropriately low estimated dry weight may be contributing; look for clues such as improved nutritional status with hypotension 9
• VTE prophylaxis: If not already anticoagulated, provide venous thromboembolism prophylaxis in patients with severe volume overload requiring intensive care 1