Can Acute Pulmonary Odema (APO) occur in Chronic Kidney Disease (CKD) stage V?

Can Acute Pulmonary Edema Occur in CKD Stage V?

Yes, acute pulmonary edema (APO) is a well-recognized and common complication in patients with CKD stage V (end-stage renal disease), occurring through multiple distinct mechanisms including volume overload, left ventricular dysfunction, increased capillary permeability, and acute lung injury. 1, 2

Epidemiology and Clinical Significance

APO is a frequent cause of hospital admission and ICU admission in chronic dialysis patients with CKD stage V. 1 In one ICU study of 102 chronic dialysis patients admitted for APO, the median dialysis duration was 2 years, with hospitalization required in the majority of cases. 1 The combination of respiratory failure and acute kidney injury carries a mortality exceeding 80%, making this a particularly devastating complication. 2

Mechanisms of APO in CKD Stage V

Volume Overload (Most Common)

• Excessive interdialytic weight gain (25% of cases) and inappropriate dry weight prescription (23% of cases) are leading precipitants of APO in dialysis patients. 1
• With glomerular filtration rates below 10-15 mL/min, sodium excretion becomes severely impaired, leading to extracellular volume expansion, edema, arterial hypertension, and heart failure. 3
• The kidneys lose their ability to maintain fluid homeostasis, and the range of urine osmolality progressively approaches plasma osmolality (isosthenuria). 3

Cardiogenic Mechanisms

• Left ventricular dysfunction and diastolic dysfunction are more common in CKD patients and contribute to hydrostatic pulmonary edema. 4
• Cirrhotic cardiomyopathy with diastolic dysfunction can cause hydrostatic pulmonary edema independent of volume status in patients with concurrent liver disease. 4
• Patients with preserved systolic function and LV hypertrophy are particularly susceptible to flash pulmonary edema because of reduced ventricular distensibility, where small changes in volume can cause large increases in filling pressures. 5

Non-Cardiogenic Mechanisms

• Increased lung capillary permeability and acute lung injury occur in CKD stage V patients, not simply volume overload. 2
• Acute pulmonary infection was the leading cause of APO in 26% of chronic dialysis patients admitted to ICU. 1
• The pathogenesis involves four distinct mechanisms: volume overload, left ventricular dysfunction, increased capillary permeability, and acute lung injury with inflammation. 2

Additional Risk Factors in CKD Stage V

• Pulmonary hypertension and chronic fluid overload in dialysis patients create additional susceptibility to APO. 6
• Hypoalbuminemia from decreased synthesis reduces plasma oncotic pressure, allowing fluid shift into pulmonary interstitium and alveoli. 4
• Oxidative stress, chronic inflammation, and endothelial dysfunction are increased in CKD and may contribute to pulmonary complications. 5

Clinical Presentation

The clinical picture typically includes:

• Bilateral decreased breath sounds at lung bases indicating pleural effusions 4
• Pitting edema reflecting systemic manifestations of decreased oncotic pressure and sodium retention 4
• Hypertension suggesting increased systemic vascular resistance 4
• Radiographic findings of hazy opacities, Kerley B lines, and "batwing" appearance on chest X-ray 4

Management Considerations

Loop diuretics are effective in CKD stage V and should be used in higher than normal doses, with combination therapy (thiazides plus loop diuretics) reserved for refractory cases. 3 However, thiazides alone have little effect in advanced CKD. 3

Renal replacement therapy should be considered for volume overload refractory to diuretics, as conservative fluid strategies may require earlier dialysis initiation. 7, 8 The duration of hospitalization for APO in dialysis patients is typically less than 4 days in 60% of cases. 1

Mortality and Prognosis

Mortality from APO in CKD stage V patients is significant, with 9% mortality in one ICU cohort (44% of deaths being cardiac in origin). 1 Being referred from another hospital service is the main predictor of death, as these patients typically arrive in critical condition. 1

Critical Pitfall

Do not assume all pulmonary edema in CKD stage V is simply from volume overload—acute lung injury and increased capillary permeability are distinct mechanisms requiring different therapeutic approaches. 2 Recognizing non-cardiogenic mechanisms may lead to specific treatment strategies beyond simple fluid removal.