Introduction: Our patient was admitted to the hospital due to shortness of breath. Although partial pressure of oxygen in arterial blood was normal, oxygen saturation measured with pulse oximetry (SpO(2)) was markedly decreased. SpO(2) and oxygen saturation of arterial blood (SaO(2)) stayed low during monitoring even with an increased fraction of oxygen in inspired air.
Methods: Report of a case.
Results: After extensive investigations, a rare haemoglobin variant, haemoglobin Titusville, with decreased oxygen binding capacity was discovered. This is the first haemoglobin Titusville case reported in Scandinavian countries.