SHM Converge Scientific Abstract ePoster Gallery-Blowing Off Some Steam (Carbon Dioxide): Olanzapine Induced Dyspnea

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This case report describes a 59-year-old man who had a prolonged postoperative ICU course after aortic root and transaortic valve replacement, complicated by cardiogenic shock, hypoxic respiratory failure, repeated failed extubations, tracheostomy, and gastrostomy tube placement. During recovery, he was started on olanzapine and dexmedetomidine for agitation and ventilator dyssynchrony.<br /><br />After olanzapine initiation, his minute ventilation gradually increased from 6.6 L/min to 9.6 L/min, with peaks up to 20 L/min, accompanied by large tidal volumes and tachypnea. Arterial blood gases showed respiratory alkalosis from excessive hyperventilation. Imaging with chest X-ray and CTA chest showed only mild pulmonary edema and small bilateral pleural effusions, findings insufficient to explain the marked increase in ventilation; pulmonary embolism was excluded. An extensive evaluation did not identify another cause, including medication review and clinical assessment.<br /><br />Because olanzapine has been rarely linked to hyperventilation, it was discontinued. Within 48 hours, the patient’s hyperventilation improved and the respiratory alkalosis resolved, supporting a causal relationship. The authors note that olanzapine is known for adverse effects such as weight gain, insulin resistance, dystonia, tardive dyskinesia, seizures, and neuroleptic malignant syndrome, but hyperventilation is an uncommon and underrecognized reaction.<br /><br />The mechanism is unclear, but may involve direct effects on the respiratory center and indirect serotonergic effects on central and peripheral chemoreceptors. The report emphasizes that olanzapine can cause increased respiratory drive even in mechanically ventilated patients, and clinicians should consider this rare adverse effect when unexplained hyperventilation occurs.

Asset Subtitle

Aung Naing

Meta Tag

Author List Aung Naing, Jacob McAuliffe, Nadeem Inayet, Rupinder Bahniwal

Category Clinical Vignettes

Concept Olanzapine

Concept Hyperventilation

Concept Medication-Induced Cause

Concept Atypical Antipsychotic

Concept Respiratory Alkalosis

Distinguished Non-Finalist

Presenter Organization EVMS at ODU

Presenting Author Aung Naing

Track Adult

Keywords

olanzapine

hyperventilation

respiratory alkalosis

mechanical ventilation

ICU

postoperative care

cardiogenic shock

tracheostomy

dexmedetomidine

adverse drug reaction

Olanzapine

Hyperventilation

Medication-Induced Cause

Atypical Antipsychotic

Respiratory Alkalosis