The sudden onset of chest pain, hypoxia, and tachycardia in a post-operative patient strongly suggests pulmonary embolism (PE), a life-threatening emergency. The immediate priority is to ensure adequate oxygenation to prevent hypoxic injury; therefore, providing high-flow oxygen is critical. Simultaneously, urgent escalation of care with emergency transfer to a higher-level facility enables prompt diagnostic workup and treatment. Delaying oxygen or transfer increases morbidity and mortality. Initiating anticoagulation or diagnostic tests without stabilization may risk delay or harm. Hence, oxygen and emergency transfer are the first essential steps.
Reference: Harrison’s Principles of Internal Medicine, Jameson et al., 20th Edition.