Pseudomonas aeruginosa Compared with Escherichia coli Produces Less Endotoxemia: Methods (1)

Pseudomonas aeruginosa Compared with Escherichia coli Produces Less Endotoxemia: Methods (1)Experimental Design
This study employed a well-characterized canine model of human septic shock.- The protocol (Fig 1) has been described previously. Comprehensive evaluations were performed at baseline (seven days prior to the onset of sepsis), and repeated on days 1, 2, and 10 after infection. These evaluations included conventional hemodynmics using femoral and pulmonary artery catheters, simultaneous radionuclide gated blood pool scans, and laboratory blood tests, including blood cultures. Cardiovascular studies were done in awake animals before and after fluid loading (80 ml/kg) at each time point. Catheters, which were inserted percutaneously using only local anesthesia (lidocaine 1 percent), were removed at the end of each study day. Descriptions of catheter placement, physiologic measurements, and routine laboratory profiles are reported elsewhere. ventolin inhaler
A total of 72 dogs were used in the current investigation. Table 1 outlines the groups studied by type and dose of bacteria and the dose of radiation. Data from 30 of the dogs used in these experiments have been reported previously. Infections were established as previously described. On day 0, fibrin clots containing known doses of bacteria in colony forming units per kilogram (CFU/kg) were surgically implanted into the peritoneal cavity of two-year-old purpose-bred beagles (10 to 14 kg) via a laparotomy under general anesthesia.


Figure 1. This figure outlines the design and time course of the experiment. All dogs in the study had a clot implanted into the peritoneal cavity. The clot was either sterile (controls) or infected with a known quantity of either P aeruginosa or E coli.

Table 1—Experimental Groups by Type and Dose of Bacteria, Dose of Radiation, and Mortality

Bacteria Dose of Bacteria, CFU x 10“/kg* Dose of Radiation, cGy No. of Dogs Mortality No. (%)
1. Sterile clot 0 0 14t 0 (0)
2. Ecoli 7 0 6t 0 (0)
3. E coli 14 0 lot 0 (0)
4. E coli 14 200 10 6 (60)
5. P aeruginosa 14 0 32 11 (34)

Category: Pseudomonas aeruginosa

Tags: aeruginosa, endotoxin, sepsis, septic shock