Pneumonia complicating abdominal sepsis. An independent risk factor for mortality
R. A. Mustard, J. M. Bohnen, C. Rosati and B. D. Schouten
Department of Surgery, Wellesley Hospital, University of Toronto, Ontario, Canada.
Nosocomial pneumonia (NP) is associated with a significant mortality, 66%
in a previous retrospective study of NP complicating intra-abdominal sepsis
(IAS). We prospectively compared the outcome of NP complicating IAS with
that of recurrent IAS (R-IAS) in the absence of NP. Data were collected
prospectively on 300 patients with IAS; 34 patients who presented with
pneumonia were excluded from the analysis (44% mortality). One hundred
seventy-one patients with no NP and no R-IAS (group 1) had a hospital
mortality of 20% (34 patients); 36 without NP in whom R-IAS developed
(group 2) had a 17% mortality (six patients); and 47 with NP but no R-IAS
(group 3) had a 53% mortality (25 patients). Finally, 12 patients who had
both NP and R-IAS suffered a 75% mortality (nine patients). We examined the
relationships among the following putative risk factors and mortality:
APACHE (acute physiology and chronic health evaluation) II score (at
initial presentation with IAS), the need for mechanical ventilatory
assistance following initial treatment for peritonitis, steroid
requirement, generalized peritonitis vs abscess, and the need for surgical
as opposed to percutaneous treatment. Using mortality as the dependent
variable, group 2 vs 3 as the explanatory variable, and the risk factors as
confounders, logistic regression analysis indicated that the group
difference was significant after controlling for confounders. We conclude
that NP complicating IAS is an independent risk factor associated with a
significant mortality compared with R-IAS. These data challenge the notion
that death in IAS is usually due to recurrent or persistent intra-abdominal
infection.
