title: The incidence and severity of hypoxia associated with 99Tcm Technegas ventilation scintigraphy and 99Tcm MAA perfusion scintigraphy.
abstract: Inhalation of the ventilatory radiopharmaceutical 99Tcm Technegas leads, in some patients, to symptoms that may be attributed to temporary lowering of oxygen saturation. In order to evaluate this, oxygen saturation was measured by pulse oximetry in a series of patients undergoing Technegas ventilation scintigraphy. A decrease in oxygen saturation was recorded in 87% of the patient group. The mean change, as a percentage of the initial value, was 8.3% (range 1-24%). Hypoxia arising in association with Technegas administration may be reduced by pre-oxygenation. In patients who were pre-oxygenated, oxygen saturation did not fall below 85% (PaO2: 50 mmHg) but in 39% of those not pre-oxygenated the value fell below this level. Oxygen saturation was also monitored in a series of patients undergoing perfusion scintigraphy. In 17% of patients a decrease was recorded (range 2-11%). In view of the large number of perfusion scans performed annually in this department and elsewhere without untoward effect, such temporary decreases in oxygen saturation presumably present no hazard to the patient.
authors.affiliation: Department of Nuclear Medicine and Medical Physics, Manchester Royal Infirmary, UK.
authors.forename: J M
authors.initials: JM
authors.lastname: James
authors.forename: J J
authors.initials: JJ
authors.lastname: Lloyd
authors.forename: B C
authors.initials: BC
authors.lastname: Leahy
authors.forename: R A
authors.initials: RA
authors.lastname: Shields
authors.forename: M C
authors.initials: MC
authors.lastname: Prescott
authors.forename: H J
authors.initials: HJ
authors.lastname: Testa
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000418:Albumins / Q000009:adverse effects; D005260:Female; D006108:Graphite / Q000009:adverse effects; D006801:Humans; D000860:Hypoxia / Q000209:etiology*; D008168:Lung / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000008:administration & dosage / Q000097:blood; D011877:Radionuclide Imaging; D013670:Sodium Pertechnetate Tc 99m / Q000009:adverse effects*; D013668:Technetium Tc 99m Aggregated Albumin / Q000009:adverse effects*
chemical_list: D000418:Albumins; D013668:Technetium Tc 99m Aggregated Albumin; C056708:Technegas; C075321:macro aggregates of albumin; D006108:Graphite; D013670:Sodium Pertechnetate Tc 99m; D010100:Oxygen