1. Protocols for De-Escalation of Intensive Therapies

Rationale: As the underlying cause of metabolic acidosis resolves and pH normalizes, a structured, gradual reduction of intravenous bicarbonate and ventilator support is critical. This approach prevents iatrogenic complications such as rebound alkalemia, hypercapnia, or volume overload, ensuring a smooth transition toward recovery.

A. Tapering Intravenous Bicarbonate

• Initiation Criteria: Begin taper when pH is consistently >7.30 and serum bicarbonate (HCO₃⁻) is ≥18 mEq/L.
• Tapering Schedule: Reduce the infusion rate by 25% every 4 hours. Check an Arterial Blood Gas (ABG) every 4–6 hours to guide further adjustments.
• Special Populations: In patients with acute kidney injury (AKI) or tenuous volume status, consider more conservative decrements of 10–15% to avoid rapid fluid and electrolyte shifts.
• Monitoring: Track cumulative sodium load daily. Monitor serum sodium, potassium, chloride, total CO₂, urine output, and body weight at least every 8 hours during the active taper.

B. Ventilator Weaning in the Context of Acidosis

• Weaning Criteria: Ensure pH >7.30, stable hemodynamics, and adequate mental status before initiating weaning protocols.
• Spontaneous Breathing Trials (SBTs): Perform SBTs once the patient’s PaCO₂ approaches their known or presumed baseline.
• Permissive Hypercapnia: To minimize ventilator-induced lung injury, a strategy of permissive hypercapnia (allowing PaCO₂ to rise to 60–70 mm Hg, as long as pH remains >7.20) may be employed. Avoid aggressive bicarbonate administration to “correct” this respiratory acidosis, as it can blunt the respiratory drive.

Case Vignette: A 58-year-old with septic shock-induced AKI has a pH of 7.32 and HCO₃⁻ of 19 mEq/L on a 4.2% sodium bicarbonate infusion. The infusion rate is reduced by 25%. An ABG 4 hours later shows pH 7.35 and HCO₃⁻ 20 mEq/L. The taper continues every 4 hours, and the infusion is successfully discontinued 16 hours later without rebound acidemia.

2. Conversion to Enteral Alkalinizing Regimens

Rationale: Transitioning from intravenous to enteral (oral or tube-fed) alkalinizing agents is a key step in de-escalation. This strategy reduces the risks associated with IV access (e.g., infection, thrombosis), lowers costs, and facilitates discharge planning for patients who may require long-term therapy.

Administration and Monitoring

• Dosing Strategy: Divide the total daily tablet requirement into 4–6 smaller doses to improve gastrointestinal tolerance and optimize absorption.
• Tube Administration: For patients with NG/PEG tubes, crush tablets and mix with water. Flush the tube with 10–20 mL of water before and after each dose to ensure full delivery and prevent clogging.
• Drug-Nutrient Interactions: Avoid co-administration with enteral feeds high in calcium or magnesium, as this can lead to the formation of insoluble precipitates.
• Monitoring: Check a basic metabolic panel (serum HCO₃⁻, Na⁺, K⁺, Cl⁻) every 24 hours for the first 48–72 hours after conversion. Once stable, monitoring can be extended to every 48–72 hours. The target is a serum HCO₃⁻ of 22–28 mEq/L and a pH of 7.35–7.45.

3. Post-ICU Syndrome (PICS) Risk and Mitigation

Rationale: Critical illness, particularly when complicated by prolonged acid–base disturbances and mechanical ventilation, is a major risk factor for Post-ICU Syndrome (PICS). PICS encompasses new or worsened impairments in physical, cognitive, and psychological health. Proactive implementation of the ABCDEF bundle is the most effective strategy to mitigate these risks and improve long-term functional outcomes.

The ABCDEF Bundle for ICU Liberation

Screening and Impact

• Screening Tools: Use validated tools like the Confusion Assessment Method for the ICU (CAM-ICU) for delirium and the ICU Mobility Scale for physical function. Psychological health can be assessed with tools like the Hospital Anxiety and Depression Scale (HADS) at follow-up.
• Proven Impact: Studies show that achieving >70% adherence to the ABCDEF bundle is associated with a 25% reduction in delirium duration, shorter time on the ventilator, and significantly improved functional outcomes at 6 months post-discharge.

4. Medication Reconciliation and Discharge Counseling

Rationale: Transitions of care are high-risk periods for medication errors. A meticulous, pharmacist-led medication reconciliation process is essential to prevent discrepancies and adverse drug events. This must be paired with clear, patient-centered discharge counseling to empower patients and caregivers in managing their own care.

Key Processes

• Reconciliation: Systematically compare pre-admission, ICU, and planned discharge medication regimens. Explicitly document the indication, dosing, and planned duration for all acid-base-related therapies, including bicarbonate, acetazolamide, and diuretics.
• Outpatient Monitoring Plan: Provide a clear schedule for follow-up labs. A typical plan includes a basic metabolic panel 1–2 weeks post-discharge, then monthly until all values are stable. Leverage telehealth and home health services for timely lab draws and adjustments.
• Patient Education Points: Counsel patients on recognizing signs of electrolyte imbalance (e.g., muscle weakness, palpitations, confusion). Provide specific dietary guidance, especially regarding sodium intake if on chronic bicarbonate therapy. Give clear thresholds for when to contact the clinic (e.g., K⁺ <3.5 or >5.0 mEq/L; HCO₃⁻ <22 mEq/L).

5. Care Coordination and Follow-Up

Rationale: Effective recovery from critical illness hinges on seamless communication between multidisciplinary teams and accessible follow-up pathways. A well-coordinated discharge ensures continuity of care, allows for early detection of complications, and reduces the likelihood of preventable readmissions.

Core Components of Safe Handoffs

• Team Communication: The discharging ICU team must provide a concise summary of the patient’s acid-base course, current regimens, and pending labs to the primary care provider (PCP) and any relevant specialists (e.g., nephrology for persistent AKI).
• Proactive Scheduling: Establish outpatient lab draw orders and schedule telehealth or in-person follow-up appointments before the patient leaves the hospital. Align check-in calls with the timing of lab results to allow for rapid adjustments.
• Comprehensive Documentation: The discharge summary is a critical communication tool. It must include a clear, actionable monitoring plan and a detailed medication list with doses, intended durations, and the rationale for each prescription.