Abstract Introduction Post-intubation stridor is a recognized complication following endotracheal intubation, commonly caused by airway narrowing from tracheal stenosis or mucosal edema. In such cases, heliox can serve as a safe and effective temporizing therapy to reduce airway resistance and improve airflow. Our case highlights how timely initiation of heliox therapy provided rapid symptomatic relief, preventing further airway compromise. Case Presentation A 74-year-old-female with past medical history of hypertension, hyperlipidemia, and coronary artery disease presented with intermittent angina and was found to have NSTEMI and three vessel coronary artery disease with plans for CABG. Her hospital course was complicated by pulseless electrical activity arrest, SCAI-D cardiogenic shock necessitating left femoral artery Impella placement, further complicated with left lower extremity ischemia requiring thrombectomy, balloon angioplasty, and fasciotomy. Patient was first intubated for hemodynamic instability and later re-intubated for pacemaker placement due to the development of complete heart block. The second intubation was complicated by traumatic airway injury and hemoptysis from right mainstem bronchus intubation treated with tranexamic acid nebulization. In the post-extubation period, she remained on non-invasive ventilation with BiPAP and intermittent high flow nasal cannula. During this period, she developed recurrent episodes of inspiratory stridor and tachypnea without hypoxemia. Laryngoscopy revealed left true vocal fold hemorrhagic epithelium, and CT of the neck revealed circumferential endotracheal soft tissue thickening and luminal narrowing approximately 3 cm below the glottis, consistent with post-intubation tracheal inflammation. After initial interventions failed, she was placed on 70:30 helium-oxygen via nonrebreather mask with rapid in her respiratory effort and stridor. She continued heliox therapy for several hours and was concurrently treated with dexamethasone 10 mg IV daily for five days with full resolution of symptoms. Discussion This case demonstrates the value of heliox as a noninvasive adjunct for post-intubation stridor caused by airway narrowing. The physiologic reasoning behind this is explained by Poiseuille's law that states airway resistance is inversely proportional to the fourth power of the radius. In tracheal stenosis, the reduction in airway radius leads to turbulent airflow, which dramatically increases resistance. Heliox, a mixture of helium and oxygen, has a density of about one-seventh that of air. By lowering the density of the inhaled gas, there is a restoration of laminar flow. This improvement in flow dynamics reduces the pressure gradient required for ventilation. In our patient, heliox provided rapid symptomatic improvement, prevented re-intubation, and allowed recovery while corticosteroids and supportive care reduced inflammation. This abstract is funded by: None
Aruleba et al. (Fri,) studied this question.