A comparative study to validate the use of ultrasonography and computed tomography in patients with post-operative intra-abdominal sepsis

Go, H.L.S.; Baarslag, H.J.; Vermeulen, H.; Laméris, J.S.; Legemate, D.A.

doi:10.1016/j.ejrad.2004.08.004

« Previous Next »European Journal of Radiology
Volume 54, Issue 3 , Pages 383-387, June 2005

A comparative study to validate the use of ultrasonography and computed tomography in patients with post-operative intra-abdominal sepsis

H.L.S. Go
- Department of Radiology, Academic Medical Center, University of Amsterdam, C-1, P.O. Box 22660, 1100 DD Amsterdam, The Netherlands
- Department of Surgery, Academic Medical Center, University of Amsterdam, Room G4-111, P.O. Box 22700, 1100 DE Amsterdam, The Netherlands
H.J. Baarslag
- Department of Radiology, Academic Medical Center, University of Amsterdam, C-1, P.O. Box 22660, 1100 DD Amsterdam, The Netherlands
H. Vermeulen
- Department of Surgery, Academic Medical Center, University of Amsterdam, Room G4-111, P.O. Box 22700, 1100 DE Amsterdam, The Netherlands
J.S. Laméris
- Department of Radiology, Academic Medical Center, University of Amsterdam, C-1, P.O. Box 22660, 1100 DD Amsterdam, The Netherlands
D.A. Legemate
- Department of Surgery, Academic Medical Center, University of Amsterdam, Room G4-111, P.O. Box 22700, 1100 DE Amsterdam, The Netherlands
- Corresponding author. Tel.: +31 20 5667832; fax: +31 20 5669243.

Received 29 April 2004; received in revised form 2 August 2004; accepted 4 August 2004.

Abstract

Purpose:

To validate abdominal ultrasonography and helical computed tomography in detecting causes for sepsis in patients after abdominal surgery and to determine improved criteria for its use.

Materials and methods:

Eighty-five consecutive surgical patients primarily operated for non-infectious disease were included in this prospective study. Forty-one patients were admitted to the intensive care unit. All patients were suspected of an intra-abdominal sepsis after abdominal surgery. Both ultrasonography (US) and helical abdominal computed tomography (CT) were performed to investigate the origin of an intra-abdominal sepsis. The images of both US and CT were interpreted on a four-point scale by different radiologists or residents in radiology, the investigators were blinded of each other's test. Interpretations of US and CT were compared with a reference standard which was defined by the result of diagnostic aspiration of suspected fluid collections, (re)laparotomy, clinical course or the opinion of an independent panel. Likelihood ratios and post-test probabilities were calculated and interobserver agreement was determined using κ statistics.

Results:

The overall prevalence of an abdominal infection was 0.49. The likelihood ratio (LR) of a positive test-result for US was 1.33 (95% CI: 0.8–2.5) and for CT scan 2.53 (95% CI: 1.4–5.0); corresponding post-test probabilities for US 0.57 (95% CI: 0.42–0.70) and for CT 0.71 (95% CI: 0.57–0.83). The LR of a negative test-result was, respectively, 0.60 (95% CI: 0.3–1.3) and 0.18 (95% CI: 0.06–0.5); corresponding post-test probabilities for US 0.37 (95% CI: 0.20–0.57) and for CT 0.15 (95% CI: 0.06–0.32) were calculated.

Conclusion:

Computed tomography can be used as the imaging modality of choice in patients suspected of intra-abdominal sepsis after abdominal surgery. Because of the low discriminatory power ultrasonography should not be performed as initial diagnostic test.

Keywords: Post-operative abdominal sepsis, Computed tomography, Ultrasonography