CASE PRESENTATION: A 55 year old male with occasional cocaine use and no significant medical history presented with slurred speech for one day. Initial vital signs showed BP 122/73, HR 64, RR 18, Tm 97.2, SaO2 84% on room air. Physical examination was notable for lethargy and slurred speech. There was no facial asymmetry or focal deficits noted. Blood work was remarkable for Na 147 and Hgb 11. Urinalysis was positive for cocaine. CT head and brain MRI were negative. Patient was given IVF with resolution of symptoms. He was noted to be persistently hypoxic without symptomatology. CT angiogram of the chest was negative for pulmonary embolism. ABG showed pO2 142 and O2 sat of 92% on 2L NC, and co-oximetry disclosed a methemoglobin level of 0.5%. Transthoracic echocardiogram with bubble study ruled out an intra-atrial shunt, and no other etiology for persistent hypoxia could be determined. On directed questioning, the patient admitted to using a combination of cocaine, tylenol PM and “poppers” the night before onset of symptoms. Patient was educated about complications from drug use. His oxygen saturation normalized spontaneously and patient was discharged with pulmonary follow up.