Supportive Care, Monitoring, and Complication Management

1. Continuous Monitoring Strategies

Continuous physiologic surveillance—vital signs, mental status, and organ function—is the foundation of safe overdose management, enabling early intervention for instability.

A. Vital Sign and Neurologic Assessment

• Vital Sign Frequency:
  • Unstable patients: every 15–60 minutes, based on toxin half-life and clinical trajectory.
  • Stable patients: every 1–4 hours, with adjustments per evolving risk.
• Neurologic Assessment:
  • Glasgow Coma Scale (GCS): every 1–2 hours; a GCS < 8 is a critical trigger for airway evaluation.
  • Sedation Scales (RASS, Ramsay): utilized for patients on sedatives or receiving intravenous lipid emulsion (IVLE).
• Cardiac Monitoring:
  • Continuous ECG is mandatory for toxins known to prolong the QT or QRS interval (e.g., tricyclic antidepressants, thioridazine).
  • Telemetry alarms must be set to detect arrhythmias promptly.

B. Organ Function Laboratory Monitoring

2. Airway Protection and Mechanical Ventilation

Early airway management in patients with depressed mental status or toxin-induced respiratory failure is critical to prevent hypoxia and aspiration.

A. Indications for Intubation

• GCS < 8, refractory hypoventilation (Respiratory Rate < 8 or PaCO₂ > 50 mmHg)
• Significant aspiration risk or severe bronchorrhea
• Exposure to potent neurotoxic agents like organophosphates

B. Rapid Sequence Intubation (RSI) and Ventilator Strategies

• Induction: Etomidate (0.2–0.3 mg/kg IV) is preferred for its hemodynamic stability. Ketamine (1–2 mg/kg IV) is an excellent alternative, especially if bronchospasm is a concern.
• Paralysis: Rocuronium (1 mg/kg IV) is the agent of choice. Avoid succinylcholine if there is a risk of hyperkalemia (e.g., rhabdomyolysis, prolonged immobility).
• Confirmation: End-tidal CO₂ via waveform capnography plus bilateral chest rise is the standard of care.
• Ventilator Strategy: Employ a lung-protective approach with a tidal volume of 6 mL/kg of predicted body weight and a plateau pressure (Pplat) ≤ 30 cmH₂O. Titrate PEEP to maintain PaO₂ > 60 mmHg or SpO₂ > 90%.

3. Metabolic and Electrolyte Management

Prompt correction of acid–base and electrolyte derangements is crucial to interrupt toxicity cycles and support organ recovery.

• Metabolic Acidosis: Administer a sodium bicarbonate bolus of 1–2 mEq/kg IV, followed by an infusion to maintain a serum pH of 7.45–7.55. For salicylate elimination, target a urine pH > 7.5.
• Electrolyte Corrections:
  • Potassium: Replete if serum level is ≤ 3.0 mEq/L, with an infusion rate ≤ 10–20 mEq/h under continuous ECG monitoring.
  • Calcium: Administer IV calcium gluconate 1–2 g for toxin-induced QT prolongation or documented hypocalcemia.
  • Phosphate: Replete with 10–30 mmol over 6 hours if level is < 1.5 mg/dL, monitoring for calcium-phosphate precipitation.
• Glucose and Nutrition: Maintain blood glucose between 80–180 mg/dL. A dextrose infusion may be necessary in specific toxidromes (e.g., isoniazid, dapsone). Initiate early enteral feeding once the airway is protected to preserve gut integrity.

4. Cardiac and Neurologic Complication Management

Seizures and arrhythmias are life-threatening complications of overdose that require rapid, protocol-driven therapy.

A. Seizure Treatment Algorithm

B. Arrhythmia and Advanced Cardiotoxicity Management

• Arrhythmias: Follow ACLS algorithms but modify based on the toxin (e.g., avoid calcium for suspected digoxin toxicity or hyperkalemia). For Torsades de pointes, administer magnesium sulfate 2 g IV over 5–10 minutes.
• Beta-Blocker/CCB Overdose: Initial therapy includes atropine (0.5 mg IV q3–5 min, max 3 mg) and IV fluids. For refractory shock, high-dose insulin euglycemia (HIE) therapy is a primary antidote.
• Intravenous Lipid Emulsion (IVLE): Indicated for severe cardiotoxicity from lipophilic drugs (e.g., bupivacaine, propranolol) unresponsive to standard care. Dose as a 1.5 mL/kg bolus of 20% lipid emulsion, followed by a 0.25 mL/kg/min infusion. Monitor triglycerides, amylase, and lipase.
• Extracorporeal Life Support (VA-ECMO): A rescue therapy for refractory shock or cardiac arrest despite maximal pharmacologic support. Cannulation is typically femoral–femoral. Weaning is considered after hemodynamic stability and evidence of cardiac recovery.

5. Multidisciplinary Care Coordination

Integrated team communication ensures the seamless delivery of complex supportive therapies and improves patient outcomes.

• Toxicology Consultation: Essential for antidote selection, dosing adjustments, and decontamination strategies.
• Nephrology Involvement: Crucial for choosing the appropriate renal replacement therapy (RRT) modality for dialyzable toxins like lithium or theophylline.
• Pharmacist Oversight: Key for reviewing drug interactions, guiding dose titrations, and planning the transition from IV to oral medications.
• Nursing Protocols: Standardized checklists for vital signs, lab draws, and infusion management reduce errors and ensure consistent care.
• Daily Huddles: Align the entire team on daily goals, pending studies, and escalation or de-escalation plans.

6. Planning for De-escalation and Outpatient Transition

Safe step-down and discharge planning are essential to prevent readmissions and manage delayed complications.

A. De-escalation Criteria

• Stable vital signs for ≥ 12–24 hours off vasopressors or other life support.
• Down-trending toxin levels to below therapeutic or toxic thresholds.
• Normalization of acid–base and electrolyte profiles.

B. Step-Down and Outpatient Follow-up

• Handoff Document: Use a standardized transfer checklist to capture outstanding labs, pending imaging, and follow-up appointments.
• Nursing Ratio Adjustment: Transition care from the ICU to a telemetry or general medical ward.
• Outpatient Follow-up: Arrange clinic visits within 7–14 days, especially for toxins with delayed effects (e.g., acetaminophen hepatotoxicity). Coordinate with psychiatry and/or addiction medicine for intentional ingestions.

7. Patient and Caregiver Education

Comprehensive discharge teaching reduces the risk of recurrence and empowers patients and caregivers to recognize early signs of complications.

• Teach-Back Method: Verify understanding of medication schedules and signs of toxicity. Ask the patient or caregiver to explain the plan in their own words.
• Medication Safety: Provide education on lockboxes, keeping medications in original containers, and using clear dosing instructions. Reconcile all home medications to avoid poly-prescribing.
• Early Warning Signs: Clearly explain which symptoms warrant immediate medical attention (e.g., chest pain, confusion, weakness, jaundice).
• Emergency Contacts: Provide the Poison Control Center contact number and clear instructions on when to call emergency services.
• Referral to Support Services: Connect the patient with substance use programs, social work, or home health services as needed.