Case Based Learning for October 2025

Ketamine-induced Laryngospasm

A 60 yo male presented for an angulated colles fracture. He was given IV dilaudid on arrival. A hematoma block was attempted, but the needle would not advance into the fracture site. Therefore, I decided to give a sub-anesthetic dose of ketamine to reduce pain during reduction. As soon as the ketamine was in, the patient’s upper body became stiff. He had a blank stare on his face and his chest stopped moving; I immediately reduced the fracture thinking the pain would initiate breathing. It did not. I let go of his arm and assisted the RN in bagging the patient. I made sure there was an excellent seal with the mask, and that the upper airway was open by performing head tilt, jaw thrust, and placing an oral airway. The pt could not be bagged; the epigastric area moved but the chest did not move with bagging. I realized that laryngospasm was preventing ventilation. O2 saturation dropped to the 77%. I ordered Ativan and the glidescope to the bedside. Then the larynx suddenly opened long enough to deliver two breaths to the lungs and the SaO2 improved. The larynx closed again for 30 seconds before reopening for a few seconds. This occurred a few times before the larynx opened and stayed open, at which time the patient breathed spontaneously and I augmented his breathing with the bag for a minute. The terrifying whole episode lasted about 6 minutes. I then placed a splint and the patient regained consciousness with complete recovery. For a few minutes, I felt like I could not continue working after the stress of this event. I went from being terrified to apprehensively hopeful that he would not be injured, to overwhelmingly grateful he was ok, all in the span of 10 minutes. I regrouped in the office for a few minutes, then I went on to the next patient.

I saw him a week later in the hospital hallway, two days after his successful surgery. He thanked me for my efforts to resuscitate him and shook my hand. I told him that I was very grateful that he recovered completely from a rare but very scary adverse drug reaction.

Ketamine-induced laryngospasm is thought to occur in 0.4% (1/250) of adults and more commonly in children (1/60); highest incidence is in infants 3-6 months. It does not seem to be dose related, but possibly more common if pushed rapidly IV. It is usually self-limited, resolving within one minute. The Larson’s maneuver is supposed to be helpful; pressing hard into the area between the mastoid bone and the ramus of the mandible. If the airway procedures described above are not working, propofol may break the spasm, with dose recommendations from a full 1-2 mg/kg to 20% of this dose. Low dose succinylcholine 0.1 mg/kg may also relieve the spasm. Progression to full sedation dose propofol and a paralytic agent with bagging or intubation would be the next step.

There is some evidence that giving propofol with ketamine (ketofol) may help reduce the incidence. Pretreatment with IV lidocaine 1 mg/kg is thought to reduce the incidence, as is giving benzodiazepines.

Excessive salivation can also occur with ketamine, especially in children; glycopyrrolate 5 mcg/kg IV (max 0.2mg) can treat this.
Please remember to always be prepared for the worst potential adverse events when using anesthetics, even when using a low dose that seems less risky. This means having the patient oxygenated, appropriately monitored, having the airway equipment and the anesthetic medication in the room, and being mentally prepared to know what you will do when these rare but serious adverse reactions occur.

Written by Mark Scott, D.O.

ERx Clinical Partners Medical Director, North Valley Hospital, Tonasket, WA

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This is for informational purposes only. For medical advice or diagnosis, consult a physician