Emergency medicine updates: The physiologically difficult airway

INTRODUCTION: Airway management is an integral skill for emergency clinicians. While most of the focus is often on anatomic challenges, clinicians must also consider the unique physiologic challenges that risk decompensation during airway management, often termed the physiologically difficult airway. OBJECTIVE: This paper evaluates key evidence-based updates concerning management of the physiologically difficult airway for the emergency clinician. DISCUSSION: Peri-intubation complications in the emergency department are often driven by physiologic instability rather than anatomic difficulty. Key phenotypes of the physiologically difficult airway include hypotension, hypoxemia, metabolic acidemia, and right ventricular dysfunction, and are associated with high rates of physiologic collapse with otherwise appropriate airway technique. Each phenotype requires targeted, physiology-driven strategies for risk mitigation. Hypotension is a strong predictor of peri-intubation cardiac arrest, with recent data emphasizing the role of pre-intubation risk stratification and targeted resuscitation with fluids, blood products, or vasopressors based on clinical scenario. For hypoxemic patients, noninvasive ventilation and high-flow nasal oxygen have demonstrated benefit in reducing peri-intubation desaturation. In metabolic acidemia, maintaining minute ventilation and minimizing apnea time are critical. Patients with right ventricular dysfunction require optimization of preload, afterload, and ventilatory strategy. Intracranial hypertension has recently received focus as a physiologically difficult phenotype, with avoidance of hypoxia, hypotension, and minimizing sympathetic surges key priorities to limit secondary brain injury. Across all phenotypes maximizing first-attempt success, preparing for rapid deterioration, and individualizing management are crucial. CONCLUSIONS: Recent evidence has advanced the understanding of how to improve care of patients with a physiologically difficult airway.