Extending ventilator circuit change interval beyond 2 days reduces the likelihood of ventilator-associated pneumonia.

OBJECTIVE: To determine the risk of acquiring ventilator-associated pneumonia (VAP) and the impact on costs when extending ventilator circuit change intervals beyond 2 days to 7 and 30 days. DESIGN: Prospective 4-year review of mechanically ventilated patients. SETTING: The respiratory and medical ICUs of an 800-bed tertiary teaching Veterans Affairs hospital. PATIENTS: All adult patients receiving mechanical ventilation from January 1991 through December 1994. INTERVENTIONS: Ventilator circuits with active heated water humidifiers were changed at 2-day intervals during a 2-year control period, followed by 7-day and 30-day intervals (for 1 year each). Heated wire circuits were adopted with the 30-day interval. The rate of VAP per 1,000 ventilator days was calculated for each circuit change interval group. Survival analysis was used to model VAP with ventilator circuit change to determine risk. RESULTS: During the study period, 637 patients received mechanical ventilation. During the 2 years with 2-day change intervals, the VAP per 1,000 ventilator days was 11.88 (n=343), compared with 3.34 (n=137) and 6.28 (n=157) for 7-day and 30-day change intervals, respectively. The risk of acquiring a VAP for those with a circuit change every 2 days was significantly greater (relative risk, 3.1; p=0.0004; 95% confidence interval, 1.662, 5.812) than those with the 7- and 30-day circuit changes. Extending circuit change intervals reduced supply and labor costs averaging $4,231/yr for each ventilator in use. CONCLUSIONS: Circuit change intervals of 7 and 30 days have lower risks for VAP than the 2-day intervals, yielding substantial reductions in morbidity as well labor and supply costs.

Seroprevalence of HTLV-I/II and HIV-1 infection among male intravenous drug abusers in Chicago.

We surveyed for serologic evidence of either HIV-1 or HTLV-I/II infection in 387 male veterans who entered into an inpatient drug treatment center. Serum was obtained after receiving written informed consent. Serum specimens were tested by enzyme-linked immunosorbent assay for antibody to HIV-1 and for antibody to HTLV-I/II; sera that were repeatedly reactive were then tested by Western blot (HIV-1/HTLV-I/II) and radioimmunoprecipitation assay (HTLV-I/II). Sixty-five of 387 (16.79%) patients were tested and confirmed as positive for HTLV-I/II only antibodies and 30 of the 387 (7.75%) were positive for HIV-1 only antibodies. An additional nine patients (2.32%) were seropositive for antibodies to both viruses. A statistically significant difference in the CD4/CD8 lymphocyte ratio was associated with HIV-1 seropositivity. HTLV-I/II seropositivity was strongly associated with black race, age, and duration of i.v. drug use, but not with sexual intercourse as determined by lifetime history of number of sexual partners, incidence of sexually transmitted diseases, type of drug used, or needle-sharing practices.

Influenza A among hospital personnel and patients. Implications for recognition, prevention, and control.

An outbreak of influenza A/Philippines H3N2 at a 1156-bed Veterans Administration Hospital involved 118 hospital personnel and 49 patients. Prospective surveillance methods that had been established within the hospital were not useful in identifying the number of involved individuals. Community indicators of influenza, which were reviewed retrospectively, would not have identified circulating influenza in this population. Control of the outbreak was accomplished using a creative approach that immunized over a third of the physician and nursing staff. This immunization program was successfully used in subsequent years to increase personnel compliance with the Immunization Practices Advisory Committee recommendations to annually immunize hospital personnel.

A comparison of pneumonia caused by gentamicin, methicillin-resistant and gentamicin, methicillin-sensitive Staphylococcus aureus: epidemiologic and clinical studies.

We investigated an outbreak of nosocomial pneumonia due to gentamicin, methicillin-resistant Staphylococcus aureus (GMRSA). We compared the predisposing factors for pneumonia due to GMRSA to those for pneumonia due to gentamicin, methicillin-sensitive Staphylococcus aureus (GMSSA). Seventeen of 29 patients with staphylococcal pneumonia were infected with GMRSA. Risk factors and associated diseases which selected for infection with GMRSA as opposed to GMSSA included prior antibiotic therapy for a prolonged period of time (p = 0.0001), number of risk factors per patient (p = 0.0001), days hospitalized prior to diagnosis of pneumonia (p = 0.002) and number of associated diseases per patient (p = 0.002). Despite the epidemiologic differences between GMSSA and GMRSA pneumonia, there were no differences in the clinical presentation, course of illness, complications, response to appropriate therapy or outcome between the two groups. Survival was adversely affected by age only among the GMSSA patients (p = 0.02) and by the number of associated diseases (p = 0.005).