Acute Kidney Injury During Oliguric and Anuric Phases: Comprehensive Management Strategies

Acute kidney injury (AKI), particularly during the oliguric or anuric phase, presents significant clinical challenges due to the kidneys' inability to produce adequate urine. This condition can rapidly disrupt the body's internal balance, leading to life-threatening complications if not managed promptly and effectively. A well-structured treatment approach is essential to support organ function and improve patient outcomes.

Maintaining Fluid Balance

During the oliguric or anuric stage of acute kidney injury, patients often experience a sharp decline in urine output, resulting in fluid retention. This excess fluid can accumulate in tissues, causing peripheral edema, generalized swelling, and even pulmonary edema—where fluid builds up in the lungs and impairs breathing. In severe cases, pericardial effusion may develop, increasing the risk of cardiac tamponade.

To counteract fluid overload, clinicians typically administer loop diuretics such as furosemide or torasemide under close medical supervision. These medications help enhance urine production when residual kidney function exists. However, their use must be carefully monitored to avoid dehydration or electrolyte disturbances once diuresis begins.

Restoring Electrolyte Homeostasis

Electrolyte imbalances are common and potentially dangerous in AKI patients. Disruptions in sodium levels—such as hypernatremia or hyponatremia—can affect neurological function and lead to confusion, seizures, or coma. Similarly, potassium dysregulation poses a critical threat; hyperkalemia, in particular, can trigger fatal cardiac arrhythmias.

Regular monitoring through blood tests, including serum electrolyte panels, is crucial for early detection. Interventions may include dietary modifications, potassium-binding agents like sodium polystyrene sulfonate, or emergency treatments such as intravenous calcium gluconate to stabilize the heart in cases of severe hyperkalemia.

Correcting Acid-Base Imbalances

Metabolic acidosis is a hallmark of acute renal failure due to the kidneys' reduced capacity to excrete hydrogen ions and regenerate bicarbonate. This acidic shift in blood pH can impair cellular metabolism, weaken myocardial contractility, and contribute to respiratory compensation with rapid, deep breathing (Kussmaul respirations).

To restore acid-base equilibrium, intravenous sodium bicarbonate is commonly administered in symptomatic or severe cases. The goal is to gradually correct pH levels while avoiding overcorrection, which could lead to metabolic alkalosis or fluid overload.

Advanced Support with Renal Replacement Therapy

When conservative measures fail to stabilize the patient, renal replacement therapy (RRT) becomes a cornerstone of management. Also known as blood purification, this includes modalities such as hemodialysis, continuous renal replacement therapy (CRRT), or peritoneal dialysis—depending on the patient's hemodynamic status and clinical setting.

RRT helps remove accumulated toxins, excess fluids, and correct electrolyte and acid-base abnormalities. It provides critical support that allows time for the kidneys to recover, especially in reversible causes of AKI such as acute tubular necrosis following ischemia or nephrotoxic exposure.

In summary, managing the oliguric and anuric phases of acute kidney injury requires a multidisciplinary, proactive approach focused on preserving vital organ function. Early recognition, vigilant monitoring, and timely intervention—including pharmacological support and dialytic therapies—are key to improving survival rates and promoting renal recovery.