Gram-negative sepsis

Klebsiella pneumoniae bacteraemia at an urban general hospital

Of 47 patients with Klebsiella pneumoniae bacteraemia admitted to the Hillbrow Hospital, Johannesburg during a period of 18 months, 31 were males and 16 were females. Features predisposing to illness were found in 89.4% patients, chronic alcoholism, neoplastic disease and diabetes mellitus being the most common. Twenty-five infections were acquired in hospital and 22 in the community. Most patients (59.6%) had pneumonia. All isolates of K. pneumoniae were resistant to ampicillin (100%); several (42.6%) were resistant to other antibiotics also. The overall mortality rate was 55.3%. A higher mean initial blood pressure and lower concentrations of serum urea and bilirubin were found in survivors. None of the 28 patients, surviving more than 48 h who received combined therapy with an aminoglycoside and a beta-lactam antibiotic (to which the organism was susceptible) died. Among the remaining patients treated with either an appropriate beta-lactam agent alone, an appropriate aminoglycoside alone or ciprofloxacin the combined mortality rate was 83.3% (P = 0.007).

Effects of ibuprofen on a pig Pseudomonas ARDS model

The effects of ibuprofen (I) were studied in the Pseudomonas (P) porcine ARDS model. Pigs, 14-26 kg (5 in each group), were anesthetized and ventilated with 0.5 FiO2 and 5 cm H2O PEEP. A control (C) group received saline only, a second group was given P, 1 X 10(8) org/ml at 0.3 cc/20 kg/min, and a third group was given P followed by 12.5 mg I at 20 and 120 min. Pulmonary arterial (PAP), wedge (PWP) and systemic arterial pressures, cardiac output (CO), and thermal-cardiogreen extravascular lung water (EVLW), thromboxane (TxB2), 6-keto-PGF1 alpha, PaO2, PaCO2 were determined every 30 min. Albumin flux was measured with scintigraphic determination of lung:heart radioactivity ratios versus time, called slope index (SI). At 3 hr, P produced marked (P less than 0.05) increases in PAP (18 +/- 7 to 37 +/- 2 mm Hg), TxB2 (471 +/- 513 to 9216 +/- 3615 pg/ml), 6-keto-PGF1 alpha, EVLW (6.4 +/- 1.4 to 14.6 +/- 5.7 mg/kg), and SI (0.4 +/- 0.2 to 1.7 +/- 0.5 X 10(-3) U/min) with decreases in PaO2 (214 +/- 47 to 101 +/- 41 torr), CO and SAP. Ibuprofen caused a rapid clearing of TxB2 and 6-keto-PGF1 alpha associated with a transient decrease in PAP; PaO2 was considerably improved compared to P; however, CO, SAP, EVLW, and SI were unaffected. Prostaglandin blockage temporarily ameliorated the pulmonary hypertension and markedly improved oxygenation in this porcine septic ARDS model, but failed to alter increased permeability, confirming other studies that the increased pulmonary shunt in ARDS is not only dependent upon capillary leak.

Three-year experience with amikacin sulfate as an exclusive surgical aminoglycoside in a large acute-care hospital

Aminoglycosides have important roles as perioperative adjunctive antibiotics in the surgical management of peritonitis. In the past, most surgeons have used gentamicin in combination with a drug aimed at intraperitoneal anaerobic pathogens, either clindamycin or metronidazole. Amikacin has been traditionally reserved for culture-proved infections due to gram-negative organisms resistant to gentamicin or other aminoglycosides. At the Minneapolis Veterans Administration Medical Center, a worrisome incidence of gentamicin-resistant hospital isolates led to a decision to make amikacin the exclusive, routine surgical aminoglycoside for all abdominal infections, as well as all hospital-acquired infections in surgical patients involving gram-negative aerobes and requiring parenteral therapy. This report describes the resultant three-year experience with amikacin in surgical patients. Data from four research studies involving these patients suggest that exclusive amikacin use has not led to the emergence of amikacin-resistant organisms or to significant nephrotoxicity. Amikacin use in surgical patients is supported in hospital environments where gentamicin resistance is judged to be a significant clinical risk factor.

Retrospective analysis of two hundred and twelve cases of bacteremia due to anaerobic microorganisms

Cases of bacteremia caused by anaerobic microorganisms and occurring during a four year period in a non-selected patient group in a Spanish general hospital were analysed retrospectively. Microbiological data was collected on 212 patients and clinical data on 103 patients. Cases of anaerobic bacteremia represented 8.6% of the total number of cases of bacteremia. Of the 232 anaerobic microorganisms causing bacteremia, gram-negative bacilli were responsible in 113 cases (48.7%), gram-positive bacilli in 92 cases (39.6%), gram-positive cocci in 25 cases (10.7%), and Veillonella spp. in two cases (0.8%). The most important clinical features were fever (64%), anemia (56%), septic shock (22%) and metastatic abscesses (21%). Patients with anaerobic bacteremia were hospitalized for an average of 51.7 days. The overall mortality was 32% and factors associated with poor prognosis were severe underlying disease, nosocomial acquisition, presence of shock, presence of metastatic foci of infection, and absence of adequate surgical drainage. The mortality rate of patients who received adequate antimicrobial therapy was 30% and that of patients who received inadequate treatment or none was 29%. It is concluded that anaerobic bacteremia has a significant rate of morbidity and mortality and that underlying disease and surgical debridement and/or drainage have greater prognostic significance than the use of antimicrobial agents.