Remifentanil‐Induced Chest Wall Rigidity in an Infant With Hepatic Failure

To the Editor,

We read with interest the recent article, “Remifentanil use in intensive care units: Current evidence and future perspectives” by Okano et al. The article suggests that remifentanil should be preferred for analgesia in patients with hepatic failure because plasma esterases metabolise it [1]. We wish to share a related pediatric case. A 4‐month‐old boy with acute hepatic failure was admitted to the pediatric intensive care unit and intubated. We chose remifentanil infusion (0.25 μg/kg/min) for sedation and analgesia. After ~5 h on remifentanil, the patient acutely desaturated (SpO₂ ≈ 80%), and tidal volume fell to 2 mL/kg. Endotracheal tube position was confirmed using end‐tidal carbon dioxide monitoring. However, bag ventilation produced no chest movement. We suspected opioid‐induced chest wall rigidity. Remifentanil was immediately stopped, and naloxone (0.1 mg/kg IV) was administered. Chest wall excursion promptly returned, and SpO₂ normalised; tidal volume improved to ~6 mL/kg on mechanical ventilation. Remifentanil was then restarted at a reduced rate (0.15 μg/kg/min) without recurrence of rigidity. As shown by Sivak and Davis, remifentanil's clearance is unaffected by end‐stage hepatic or renal failure, making it suitable for use in patients with hepatic failure [2]. However, clinicians must be aware of the rare but serious risk of opioid‐induced chest wall rigidity, which can also occur in intubated patients under mechanical ventilation. In such cases, warning signs include a sudden rise in peak airway pressures, reduced tidal volumes despite adequate ventilator settings, poor chest wall expansion, and unexplained oxygen desaturation [3]. Chest wall rigidity may occur with small doses, especially in neonates and infants. A recent systematic review similarly noted that chest wall rigidity is a common side effect of remifentanil in neonates and infants, emphasising prevention by slow infusion and minimal dosing [4]. Our experience is consistent with previous reports: even small opioid doses may induce rigidity in neonates and infants [3].

When rigidity occurs, it must be recognized and treated immediately. As in our patient, chest rigidity is rapidly reversible with naloxone. In our case, naloxone promptly restored adequate ventilation without needing paralysis. This pediatric case supports the use of remifentanil in hepatic failure (extrahepatic metabolism ensures predictable clearance) while highlighting “wooden chest syndrome” as a rare but critical complication. Clinicians should be alert for chest wall rigidity during opioid infusions in intubated patients and be prepared to intervene (naloxone or paralysis) to prevent hypoxemia.

Conflicts of Interest

The authors declare no conflicts of interest.

Linked Articles

This article is linked to Okano et al. paper. To view this article, visit https://doi.org/10.1002/ams2.70087.