Internal surgery patients with infectious complications shown not to benefit by extra CT
Thoracic CT is safely and wisely omitted from diagnostic protocols for ICU patients who have signs of infection after abdominopelvic surgery but were already imaged with abdominal CT.
So conclude radiology researchers at Technical University Dresden in Germany whose study was published Feb. 10 in Annals of Intensive Care [1].
Reviewing records of 143 thoracoabdominal CTs bearing 297 thoracic pathologies, Heiner Nebelung, MD, and colleagues found adding thoracic CT after abdominal CT contributed little clinical guidance since most pathologic thoracic findings were visible below the diaphragmatic dome.
In 23 of the 143 scans, thoracic pathologies did turn up that were only visible above the dome, nabbing previously unknown pathologies at a rate of 16.1%.
However, patient management changed in just one (0.7%) of these cases.
Further, when it came to identifying an infection’s focal site, the diagnostic efficacy was just 3.5%.
“The widespread use of thoracic CT in this patient population should be critically evaluated on an individual level, particularly since many relevant thoracic pathologies are readily visible on abdominal CT,” Nebelung and co-authors remark.
The authors suggest the value of their project lies in its look at the use of chest CT vs. chest X-ray in the intensive care setting, the latter having been extensively studied.
They cite a 2002 German study showing thoracic CT had a high rate of therapeutic consequence over that of chest X-ray, changing clinical management in half of 558 CT studies.
Nebelung and co-authors note the earlier study included many patients who had numerous primary or secondary diagnoses. Only 35% of CTs were ordered to find an infectious focus, and 65% of indications were such pulmonary pathologies as deteriorating gas exchange, possible misplacement of thoracic drain and pulmonary embolism.
“This plausibly explains why in our study we found markedly lower numbers of previously unknown pulmonary diagnoses as well as less therapeutic consequences,” Nebelung and colleagues write.
More:
Another reason could be that we assessed if pathologies were only visible on thoracic CT (above the diaphragmatic dome) or also on abdominal CT (including the diaphragmatic domes and lower lungs), which reduced diagnostic efficacy to 16.1%. The most common findings (57.7%) in the study of Dorenbeck et al. were dys-/atelectases, pneumonic infiltrates and pleural effusions, which is in keeping with our results.”
The new study is available in full for free.