Clinical Practice and Cases in Emergency Medicine

Introduction: The differential diagnosis for altered mental status and respiratory failure is broad. Careful physical examination, appropriate use of diagnostic tools, and accurate interpretation and correlation of test results are important for piecing together the puzzle of a patient with altered mental status that emergency physicians commonly face. In certain cases, such as this one, rapid diagnosis and management is crucial for improving patient morbidity and mortality.

Case Presentation: A 48-year-old male with altered mental status and respiratory failure presented to the emergency department after being found unconscious on his porch. Vital signs were notable for temperature 105.5 °F, blood pressure 202/102 millimeters of mercury, pulse 126 beats per minute, respiratory rate 30 breaths per minute, and oxygen saturation 91% on room air. Physical examination revealed an obese male lying in bed awake in severe distress with labored breathing and unable to converse. His physical examination was significant for dry mucous membranes, tachycardia, and bilateral lower extremity 1+ pitting edema. He also appeared to have Kussmaul respirations with severe tachypnea, but his breath sounds were clear to auscultation bilaterally. On further examination, the patient appeared to have intravenous (IV) injection markings along his arms suggesting the possibility of IV drug use.

Discussion: With limited history, the only context clues initially available to assist in the diagnosis were abnormal vital signs and physical examination. The patient was tachycardic, hyperthermic, hypertensive, hypoxic, and tachypneic with altered mental status; he eventually required endotracheal intubation for hypoxic respiratory failure. The complexity of his condition prompted a large list for the differential diagnoses. Toxidromes, endocrine abnormalities, infectious process, cardiac and/or renal etiologies, and neurological pathology such as a cerebrovascular accident were considered. In the case of this patient, urgent diagnosis and management was crucial to prevent further decompensation and improve his outcome.