Relevance of CT for the detection of septic foci: diagnostic performance in a retrospective cohort of medical intensive care patients

AIM

To analyse the diagnostic yield of computed tomography (CT) in septic patients from a medical intensive care unit (ICU).

MATERIALS AND METHODS

A full-text search of the department's radiological information system (RIS) retrieved 227 body CT examinations undertaken to search for a septic focus in 2018 from medical ICU patients. CT reports were categorised according to the identified foci. Clinical and laboratory information was gathered. Data were analysed statistically using descriptive statistics, diagnostic test quality criteria, binomial tests and chi-square test.

RESULTS

A total of 227 CT examinations from 165 septic patients detected 264 foci, which were distributed as follows: 58.3% (n=154/264) chest, 26.5% (n=70/264) abdomen, 5.3% (n=14/264) genitourinary system, and 9.8% (n=26/264) other body regions. In 15.9% (n=36/227) no focus was identified on CT. Based on CT reports, 37.5% (n=99/264) of foci were graded as certain, 18.9% (n=50/264) as likely, and 15.9% (n=42/264) as possible infectious sources. Septic foci were detected using CT with 75.8% sensitivity (95% confidence interval [CI] 69.6-81.9%) and 59.46% specificity (95% CI 42.9-76.1%). The positive predictive value was 90.6% (95% CI 86-95.2%), with a negative predictive value of 32.4% (95% CI 21-43.8%).

CONCLUSION

The present results confirm that body CT is a suitable rule-in test for septic patients in medical intensive care, although it cannot reliably rule out a septic focus. Follow-up CT examinations may reveal a septic source in the further course of a patient's hospital stay.

The relationship of neck orientation to the shape of the proximal femur

Neck angles and various dimensions measured from 70 normal cadaver femora and from clinical radiographs of 120 normal hips were analyzed. The neck-shaft angle and the inclination of the medial trabecular system varied over a range of approximately 35 degrees. The location of the femoral head center in relation to the femoral shaft and to the trochanters was related to neck orientation. As the neck became vertical, horizontal offset of the head center from the shaft decreased and its vertical level relative to that of the trochanter increased. The abductor muscle lever arm was measured with two methods. Values obtained when assuming that the joint resultant force follows the medial trabeculae demonstrated the closest relationship to the distance from head center to body midline. The normal shape of the proximal femur is variable, and variations in the absence of intrinsic bone disease appear to reflect adaptation to physiologic variations in the line of action of muscle forces.

Left-to-right shunt via left superior vena cava communication with left atrium

The findings in a 22-year-old man with Ebstein's anomaly of the tricuspid valve, Wolff-Parkinson-White syndrome, and a persistent left superior vena cava are reported. This is the first reported case of this combination of anomalies in which the atrial septum was intact and the left superior vena cava communicated with the left atrium. Uniquely, blood was shunted left to right via the left superior vena cava from the left atrium. Only one previous case of left-to-right shunting via a left superior vena cava (in the absence of mitral valvular disease or cor triatriatum) has been reported (associated with aortic coarctation). Angiograms demonstrated the left atrial connection of the left superior vena cava to be at the entrance of the right superior pulmonary vein into the left atrium. In the absence of demonstrable left-sided heart disease, this anatomic juxtaposition is suggested as a possible explanation for the direction of shunting.