The clinical use of 99m-Tc-labeled WBC scintigraphy in critically ill surgical and trauma patients with occult sepsis.

OBJECTIVE

To evaluate the clinical use of radionuclide-labeled white blood cell scintigraphy in the detection of focal sepsis.

DESIGN

Prospective clinical study.

SETTING

A medical/surgical 12-bed intensive care unit (ICU) in a university hospital.

PATIENTS

26 trauma and surgical patients affected by sepsis of unknown origin were studied.

MEASUREMENTS AND RESULTS

After the usual diagnostic approach, patients were submitted to a total body scan by using the patient's leukocytes labeled with technetium-99m (99m-Tc) HMPAO; three scintigraphy were performed within 20 h of tracer injection; the result of scan was completed with all clinical and instrumental data, including ultrasound (US) arnd computed tomography (CT), and the diagnostic efficacy was demonstrated for each patient on discharge from the ICU. The scan was able to detect 20 sites of infection; it was possible to rule out 11 suspected sites; only in two cases was the result considered to be false positive or false negative; in two cases the result was considered to be uncertain. These results show the high sensitivity (95%), specificity (91%) and accuracy (94%) of the method.

CONCLUSIONS

In ICU patients with sepsis, nuclear medicine can provide additional data, as the injection of radionuclide-labeled white blood cells (WBCs) allows the imaging of sites of infection. Analysis of our results suggests that scintigraphy with 99m-Tc-labeled WBCs can be considered a useful tool in the detection of the source of infection.