Cardiorespiratory Trajectory, ROX Index Extubation Failure, and Post-Tracheostomy Liberation in Pediatric Odontogenic Ablett Grade IV Tetanus Complicated by Cardiac Arrest: An Observational Analytic Case Study

Background: Ablett Grade IV tetanus from an odontogenic portal carries high mortality in resource-limited settings because of laryngospasm, autonomic instability and prolonged ventilation. Objective: To describe the cardiorespiratory course, extubation failure by the Respiratory Rate-Oxygenation (ROX) index, and post-tracheostomy liberation in an unimmunized, severely undernourished child with odontogenic Grade IV tetanus. Methods: This single-patient case report followed a boy through a 20-day hospital course within 37 days of follow-up (October 1 to November 6, 2024) at Dr. M. Djamil General Hospital, Padang, Indonesia (ethics protocol CMHC/EC/IRB/2026/0418). Oxygenation indices, the ROX index, the neutrophil-to-lymphocyte ratio (NLR) and the systemic immune-inflammation index (SII) were calculated from serial records. Results: The unimmunized boy, aged 4 years 2 months, weighed 11.0 kg (weight-for-age Z-score −3.0 SD) and had rampant dental caries, 1.0 cm trismus, opisthotonus, aspiration bronchopneumonia and hypertension (130/85 mmHg). On Day 2, reflex spasms rose to 10–12 episodes/day (NLR 7.36; SII 3,946.9 × 10³/μL), followed by apneic cardiac arrest (SpO₂ 80%, PaO₂/FiO₂ 106.7 mmHg). Extubation to high-flow nasal cannula on Day 7 failed within 2 hours (SpO₂ 82%, ROX index 2.2). After meropenem for ceftriaxone-resistant Pseudomonas sp. bacteremia and elective surgical tracheostomy on Day 9, he was weaned to a T-piece within 24 to 48 hours and continuous sedatives were stopped, and enteral baclofen was started. Spasms had resolved by Day 19; decannulation was scheduled for Day 39. Conclusion: In this child, surgical tracheostomy after ROX-documented extubation failure was followed by rapid ventilator liberation and sedative de-escalation. Causation cannot be shown.