One hour after a bone marrow biopsy and inhalation of Entonox gas (50% nitrous oxide (N2O) and 50% oxygen), a patient had a markedly reduced transfer factor of the lung for carbon monoxide (TL,CO). Three hours after Entonox, the patient had a normal TL,CO. Since carbon monoxide (CO) and N2O have similar spectral wavelengths, it was proposed that residual N2O in the lungs was interfering with th...
