THE 1-MONTH OUTCOME OF PATIENTS WITH A LOW PROBABILITY TECHNEGAS VENTILATION-PERFUSION LUNG-SCAN

The objective was to study the 1-month outcome of patients who had a l ow probability ventilation/perfusion lung scan using Technegas radioae rosol as the inhalational agent and who did not receive anticoagulatio n. One hundred consecutive patients with suspected pulmonary embolism were studied retrospectively. Their Technegas lung scans were classifi ed by two blinded and independent nuclear medicine physicians and the medical records of all patients with a low probability scan were revie wed. One hundred inpatients (42 males and 58 females) with a mean age of 63 years were studied. The three most common clinical presentations leading to lung scintigraphy were unexplained dyspnoea (30 cases), un explained dyspnoea with pleuritic chest pain (26 cases) and pleuritic chest pain only (15 cases). Nine patients had been judged by their man aging medical team to have a high clinical probability of true pulmona ry embolism, 32 had an intermediate probability clinical presentation and 59 a low clinical probability of pulmonary embolism. None of the 1 00 patients experienced further episodes of suspected or proven pulmon ary embolism during the follow-up period. Six patients died. In none o f them was pulmonary embolism either the cause of or a major contribut ing factor to death. The finding of a low probability scan using Techn egas as the ventilation scintigram agent of choice describes a group o f patients who, even in the absence of therapeutic anticoagulation, ha ve a favourable 1-month outcome free of either true or suspected clini cal pulmonary embolism. Invasive, pulmonary angiography-based diagnost ic strategies may not be needed in this group of patients.