Intraabdominal infections sepsis

This chapter outlines methods to produce sepsis associated with either intra-pulmonary or intraabdominal infections in rabbits. Methods are included for creating focal infections in the lungs or in the peritoneal cavity, for monitoring the physiological responses, and for assessing tissue-specific inflammatory and injury responses. 

Intraabdominal infections have a wide spectrum of clinical features often depending on the specific disease process, the location and the magnitude of bacterial contamination, and concurrent host factors. Patients with primary and secondary peritonitis present quite differently (Table 42-3). If peritonitis continues untreated, the patient may experience hypovolemic shock from fluid loss into the peritoneum, bowel wall, and lumen. This may be accompanied by generalized sepsis. Intraabdominal abscess may pose a diagnostic challenge as the symptoms are neither specific nor dramatic. 

Many of the manifestations of intraabdominal infections, particularly peritonitis, result from cytokine activity. Inflammatory cytokines, such as tumor necrosis factor a (TNF-a), interleukin 1 (IL-1), IL-6, IL-8, and interferon-y (INF-y), are produced by macrophages and neutrophils in response to bacteria and bacterial products or in response to tissue injury resulting from the surgical incision. These cytokines produce wide-ranging effects on the endothelium of organs, particularly the liver, lungs, kidneys, and heart. With uncontrolled activation of these mediators, sepsis may result (see Chap. 117). 

Mustard RA, Bohnen JMA, Rosati C, Schouten D. Pneumonia com- Solomkin JS, Mazuski JE, Baron EJ, et al. Guidelines for the selection plicating abdominal sepsis. Arch Surg 1991 126 170-175. of anti-infective agents for complicated intraabdominal infec-... 

H13. Hamilton, G., Hofbauer, S and Hamilton, B., Endotoxin, TNF-alpha, interleukin-6 and parameters of the cellular immune system in patients with intraabdominal sepsis. Scand. J. Infect. Dis. 24,361-368 (1992). 

The sites of infections that most frequently led to sepsis were the respiratory tract (21% to 68%), urinary tract (14% to 18%), and intraabdominal space (14% to 22%). Sepsis may be caused by gram-negative (38% of sepsis) or gram-positive bacteria (40%), as well as by fungi (17%) or other microorganisms. 

Sitges-Serra A, Lopez MJ, Girvent M, et al. Postoperative enterococcal infection after treatment of comphcated intraabdominal sepsis. Br J Surg 2002 89 361-367. 

After the source of infection is identified, prompt efforts to remove or eliminate the source should be initiated. With an infected intravascnlar catheter, the catheter should be removed and cnltured. Urinary tract catheters should be removed if association with sepsis is suspected. Suspicion of soft tissue (cellulitis or wound infection) or bone involvement should lead to aggressive debridement of the affected area. Evidence of an abscess or sepsis associated with any intraabdominal pathology should prompt surgical intervention. 

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