Happy Hypoxia: A case series

Abstract

“Happy hypoxia” is defined as pronounced hypoxemia without any complaints shortness of breath. During early part of COVID pandemic, “Happy Hypoxia” was extensively discussed as sign of COVID infection, leading to inadvertent sale of over-the-counter pulse oximeters. Hence, many patients presented to clinics with happy hypoxia, even with non-COVID-19 related causes. Cases Patient 1: 28 year, female, under treatment for menorrhagia was referred to our COVID clinic with lower oxygen saturations without any respiratory symptoms. She had features of right lower limb deep vein thrombosis and was diagnosed to have pulmonary embolism on CT pulmonary angiography. She was hemodynamically stable and was managed with oral anticoagulation. Patient 2: 34-year female, presented with incidentally detected low saturations on pulse oximetry. She had a history of primaquine intake 2 weeks ago for falciparum malaria. ABG analysis showed low pO2 with raised methemoglobin level (13.5%). Patient was managed conservatively as a case of Methemoglobinemia. Patient 3: 42 year, obese male, with low saturations on pulse oximetry, complained of excessive daytime sleepiness and tiredness. ABG showed signs of chronic hypoventilation. Patient was treated as a case of Obesity Hypoventilation Syndrome. Patient 4: 52 year, male, presented with low saturations seen on a recently bought pulse oximeter. He denied any respiratory symptoms and the initial workup was negative for the causes listed above. Hb electrophoresis revealed the presence of abnormal Hb Koln. The patient was referred to hematology unit. <b>Conclusion:</b> Since all of these patients presented to our clinic as presumptive COVID patients, our series highlights the need of careful evaluation of patients with happy hypoxia for causes other than COVID-19.