title: Arterial oxygen saturation in patients undergoing perfusion lung scanning with 99Tcm-labelled macroaggregates of human serum albumin.
abstract: Radionuclide imaging of the lungs with 99Tcm-labelled macroaggregates of human serum albumin (99Tcm-MAA) is a safe, reliable and non-invasive method of diagnosing pulmonary embolism. It has been suggested that following intravenous injection of 99Tcm-MAA, arterial oxygen saturation falls significantly. Oxygen saturation was measured in 101 patients who had received an intravenous injection of 99Tcm-MAA prior to a perfusion lung scan. Readings were taken using a pulse oximeter at rest, immediately following injection, 10, 30 and 60 min post-injection. Twenty-five normal volunteers who were not injected acted as controls. Forty patients showed no change in oxygen saturation throughout the study. A fall of 1% was seen in 32 patients and 2-3% in 26 patients. Of the three patients who demonstrated a reduction in saturation of 6, 7 and 13%, two had chronic airways disease and one had left ventricular failure. Twenty out of 25 normal controls showed no change in saturation over the period of observation. Five showed a fluctuation of 1-2% between the measurements. All patients and controls remained asymptomatic with almost all readings returning to the initial values after 1 h. It was the patients with chest or heart disease who showed a fall in saturation. The study shows that the majority of patients undergoing a perfusion scan with 99Tcm-MAA show no significant fall in oxygen saturation. If a fall occurs, it may be related to the underlying disease process rather than to 99Tcm-MAA.
authors.affiliation: Regional Department of Nuclear Medicine, Royal Liverpool Hospital, UK.
authors.forename: K K
authors.initials: KK
authors.lastname: Balan
authors.forename: R S
authors.initials: RS
authors.lastname: Nagra
authors.forename: M L
authors.initials: ML
authors.lastname: Smith
authors.forename: M
authors.initials: M
authors.lastname: Critchley
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006333:Heart Failure / Q000150:complications; D006801:Humans; D007275:Injections, Intravenous; D008173:Lung Diseases, Obstructive / Q000150:complications; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood*; D005082:Physical Exertion; D011655:Pulmonary Embolism / Q000097:blood / Q000150:complications / Q000000981:diagnostic imaging*; D011877:Radionuclide Imaging; D013668:Technetium Tc 99m Aggregated Albumin / Q000008:administration & dosage / Q000009:adverse effects*
chemical_list: D013668:Technetium Tc 99m Aggregated Albumin; D010100:Oxygen