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Negative Pressure Pulmonary Oedema — FRCA Final MCQ

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ModeratePaediatric AnaesthesiaNegative Pressure Pulmonary OedemaFRCA Final

A 6-year-old child (22 kg) is having a tonsillectomy. The surgeon uses bipolar diathermy. On emergence, the child bites the endotracheal tube and develops negative pressure pulmonary oedema. What is the pathophysiology?

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Correct answer: D — Forceful inspiratory effort against a closed glottis generating highly negative intrathoracic pressure

Negative pressure pulmonary oedema (NPPE/post-obstructive pulmonary oedema) occurs when vigorous inspiratory efforts are made against an obstructed upper airway (closed glottis, laryngospasm, biting the ETT). The highly negative intrathoracic pressure (-50 to -100 cmH2O) increases venous return, increases pulmonary capillary transmural pressure, and causes transudation of fluid into the alveoli. Treatment: CPAP/PEEP (5-10 cmH2O), supplemental oxygen, diuretics in severe cases. Most cases resolve within 12-24 hours with supportive care. Intubation and ventilation may be required in severe cases.

Reference: RCOA – 2023 – Paediatric anaesthesia; APA – 2019 – Post-operative complications