Negative-pressure pulmonary edema
Stem
A 23-year-old man, 92 kg, a competitive rower, has had septoplasty and turbinate reduction under general anesthesia. At extubation he developed laryngospasm with strong inspiratory efforts, which broke with positive pressure and propofol. Fifteen minutes later in recovery his SpO2 is 86% on a face mask at 10 L/min, he is coughing pink frothy sputum, he has crackles at both bases, heart rate is 112 and blood pressure 138/80.
Question
What do you think is happening, and how will you manage him?
Ideal answer
HeadlineNegative-pressure pulmonary edema until proven otherwise: hypoxemia and frothy pink sputum minutes after forced inspiration against a closed glottis. Oxygen and airway first.
- Sit him up, clear the pharynx, confirm nothing obstructs, because relieving the obstruction stops the negative pressure.1
- CPAP or noninvasive ventilation with a high FiO2, since he is awake and protecting his airway: positive pressure pushes fluid out of the alveoli, and more than half improve on NIV alone.2
- Intubate with PEEP if he tires or stays hypoxemic, or cannot cooperate.3
- No reflex furosemide: a pressure injury, not volume overload, and diuretics are controversial here.2
- Exclude the mimics: ECG, troponin and BNP, radiograph, blood gas and a quick echo for a cardiogenic cause, and consider aspiration, residual blockade and anaphylaxis.1
Watch for: Work of breathing, saturation and secretions in a monitored bed, not home; improvement expected within 12–48 hours.1
Breaking down the answer
- Name it from the history — young age, male sex, and upper airway surgery or obstruction are the recognized risk factors, and he has all three.2 Changes if: slow onset hours later with a big fluid balance, which points elsewhere.
- Mechanism, briefly — normal pleural pressure is about −3 to −10 cmH2O; a Müller maneuver against a closed glottis drops it to −50 to −100, raising venous return and LV afterload and pulling fluid into the alveoli.2 It answers the examiner's "why" early.
- Why PEEP — it improves oxygenation and lowers the FiO2 needed, whether by mask or through a tube.3
- Changes if the heart is the cause — a poor ventricle or valve lesion found on the workup changes the plan to diuresis and inotropes.1
- Two types — type 1 follows acute obstruction, such as laryngospasm; type 2 follows relief of chronic obstruction, such as tonsillectomy for obstructive tonsils.2
Follow-up question
Forty minutes later on CPAP he is agitated, pulling at the mask, breathing 36 times a minute, and his SpO2 is 80%. What now?
Follow-up answer
HeadlineNoninvasive ventilation has failed. I tell the recovery nurse and call for help and the difficult airway cart.
I preoxygenate as well as I can and perform a rapid sequence induction with an agent that keeps his blood pressure, a full intubating dose of relaxant and video laryngoscopy, because his airway was recently instrumented and he has pink secretions. I suction the tube, confirm with capnography, and ventilate with low tidal volumes and PEEP of 5–10 cmH2O, raising PEEP to match his FiO2. He goes to the ICU sedated, with an early blood gas. I reassess oxygenation, the radiograph and the cuff leak before extubation, which I expect within a day.3
Pitfalls that cost points
- Missing an ongoing obstruction, such as a patient biting the tube or residual laryngospasm.
- Omitting a bite block, since biting an endotracheal tube is a recognized cause.1
Rapid-fire
Q: How soon does it appear? A: Usually within minutes of the obstruction, though cases presenting hours after extubation are described.2
Q: What is the commonest cause in adults? A: Post-extubation laryngospasm; in children, croup and other upper airway obstruction.2
Q: How common is it? A: Estimates range from 0.1% to 12% depending on the population, and it is likely underdiagnosed.1
Q: How do you prevent it? A: Extubate deep or fully awake, use a bite block, and treat laryngospasm early with CPAP and deepening.
Q: What is the prognosis? A: Excellent when the airway is restored promptly, with improvement in 12–48 hours.1
Numbers to know
| Item | Value |
|---|---|
| Normal pleural pressure | −3 to −10 cmH2O2 |
| Pleural pressure against closed glottis | −50 to −100 cmH2O2 |
| Incidence | 0.1–12% by population1 |
| Improve on NIV | More than 50%2 |
| Typical resolution | Clinical improvement 12–48 h;1 imaging usually clears in 12–24 h3 |
Links
Sources
- 1.Negative-pressure pulmonary edema · CMAJ (Lemyze, Granier, Marshall), 2026 · ebi.ac.ukFull text via Europe PMC (PMC13374696); CMAJ 2026;198(26):E1021.
- 2.Negative-Pressure Pulmonary Edema: A Perioperative Emergency · Cureus, 2025 · ebi.ac.ukFull text via Europe PMC (PMC12508604); pathophysiology, type 1 and type 2, NIV and diuretic evidence.
- 3.Negative pressure pulmonary edema (Review) · Experimental and Therapeutic Medicine, 2023 · ebi.ac.ukFull text via Europe PMC (PMC10443067).
Facts on this page were checked against these sources on Oct 16, 2026. Guidelines change; confirm doses against current institutional protocols.