11.2 Acute Kidney Injury and High-Risk Dialysis Initiation

Why Acute Care Differs

A patient with acute kidney injury (AKI) may need dialysis because of refractory hyperkalemia, pulmonary edema, acidosis, symptomatic uremia or a selected poisoning. The underlying problem may be reversible. This differs from assuming permanent nephron loss in established maintenance treatment. The nurse tracks renal recovery and changing needs while responding to the acute illness that caused the injury.

Review recent creatinine, urine output, hemodynamics, medication exposure, fluid balance and imaging or obstruction findings. AKI can occur on top of CKD. A prior stable outpatient creatinine and a documented baseline help interpret the current change. Anuria requires prompt evaluation, but it does not identify the cause by itself. Correcting obstruction, sepsis, bleeding or a nephrotoxic exposure may change the course even while dialysis supports the patient.

Preparation and Prescription Verification

Confirm the indication, modality, access permission, duration, blood and dialysate flows, bath, fluid goal, anticoagulation and laboratory schedule. A standard outpatient four-hour prescription may be inappropriate for a first dialysis in marked azotemia or a patient needing vasopressors. Discuss instability and neurologic risk with the nephrologist rather than independently lowering or increasing efficiency.

Urgent access is commonly a nontunneled catheter, but the inserting team chooses the site and confirms position and readiness. Check catheter integrity, secure connections and use aseptic technique. Avoid assuming the catheter can be used solely because it is visible. Review recent surgery, active bleeding, thrombocytopenia and exposure to heparin before implementing the anticoagulation plan.

Modality and Hemodynamic Risk

Intermittent HD clears solutes rapidly, while continuous kidney replacement therapy provides slower ongoing fluid and solute control. Prolonged intermittent techniques occupy an intermediate practical role. The team considers circulation, neurologic status, toxin urgency, resources and expertise. Continuous treatment is not automatically superior for every patient, and intermittent treatment is not automatically safe because a machine is available.

In severe hemodynamic instability, fast removal may worsen organ perfusion. A patient can be edematous and have poor effective arterial volume. The fluid goal depends on the actual assessment and overall resuscitation plan. Monitor pressure, pulse, consciousness, respiratory state and the response to each intervention. New instability requires immediate evaluation for the cause, including sepsis, bleeding, arrhythmia or a treatment reaction.

Protect Against Rapid Osmotic Change

Marked azotemia, first dialysis, resumed treatment after prolonged absence and neurologic vulnerability raise concern about dialysis disequilibrium. The clinician may prescribe lower initial efficiency, shorter initial treatment, staged sessions or another modality. Membrane flux alone does not define urea efficiency. Do not infer that a high-flux membrane is categorically forbidden or that simply reducing the blood flow makes every prescription safe.

New headache, vomiting, confusion or seizures requires urgent assessment. Check for hypoglycemia, stroke, electrolyte abnormalities and other emergencies as well as disequilibrium. A diagnostic label should not delay stopping unsafe exposure or protecting the airway. The nurse follows emergency orders for severe neurologic symptoms; hypertonic agents are not given merely because a patient reports an ordinary headache.

Dynamic Medication and Electrolyte Needs

AKI changes medication clearance, but recovery may change it again. Ask pharmacy and the prescriber to review antibiotics, sedatives, anticoagulants and nephrotoxic agents. Drug dosing depends on the actual modality and delivered treatment, not just 'on dialysis.' Interruptions in continuous therapy can substantially change clearance and should be communicated.

Potassium and phosphate may fall during repeated or continuous therapy, sometimes requiring ordered replacement. A low-potassium bath copied from the first emergency can become inappropriate after stabilization. Monitor laboratory trends and specimen timing. Include nutrition, transfusions and all infusions in fluid accounting. Critically ill patients may receive substantial volume outside the dialysis circuit, so a machine UF total alone does not describe net daily balance.

Recovery and Continuity

Record urine output accurately and distinguish spontaneous output from output influenced by diuretics. A rise in urine volume suggests possible recovery but does not prove adequate solute clearance. The nephrologist evaluates kidney function and whether treatment can be reduced or stopped. Nurses do not omit a scheduled session based on one improved creatinine or extend permanent-access planning to every acute patient without review.

At transfer from hospital to outpatient care, identify that the patient has AKI, the suspected cause, current recovery assessment, access plan, prescription, medications and monitoring schedule. Avoid relabeling the patient as irreversible ESKD for convenience. Communicate recent instability and specify the responsible clinician for pending results. An AKI patient may require frequent changes that a stable maintenance workflow would miss.

Worked Priority Example

A septic patient with edema, potassium 6.4 mEq/L, increasing oxygen needs and low BP is referred for kidney replacement therapy. Priorities include stabilization, emergency potassium measures under orders, a carefully chosen modality and a fluid goal that accounts for perfusion. Simply maximizing UFR to reach an old target weight would be unsafe. The treatment supports the acute illness while the team continues infection control, hemodynamic care and recovery assessment.

Source: KDIGO AKI guideline.

Acute-Treatment Checks

• Confirm the indication, current prescription and access readiness.
• Review perfusion, bleeding and neurologic risk before initiation.
• Track delivered treatment, fluid balance and changing electrolytes.
• Communicate urine-output trends and the team’s recovery assessment.