Jean-Pierre Revelly

Exogenous sources of pseudomonas aeruginosa in intensive care unit patients: implementation of infection control measures and follow-up with molecular typing.

BACKGROUND In 1998, a study in the intensive care unit (ICU) of our institution suggested possible transmission of Pseudomonas aeruginosa from faucet to patient and from patient to patient. Infection-control measures were implemented to reduce the degree of P. aeruginosa colonization in faucets, to reduce the use of faucet water in certain patient care procedures, and to reduce the rate of transmission from patient to patient. OBJECTIVE To evaluate the effect of the control measures instituted in 1999 to prevent P. aeruginosa infection and colonization in ICU patients. DESIGN Prospective, molecular, epidemiological investigation. SETTING A 870-bed, university-affiliated, tertiary care teaching hospital. METHODS The investigation was performed in a manner identical to the 1998 investigation. ICU patients with a clinical specimen positive for P. aeruginosa were identified prospectively. Swab specimens from the inner part of the ICU faucets were obtained for the culture on 9 occasions between September 1997 and December 2000. All patients and environmental isolates were typed by pulsed-field gel electrophoresis (PFGE). RESULTS Compared with the 1998 study, in 2000 we found that the annual incidence of ICU patients colonized or infected with P. aeruginosa had decreased by half (26.6 patients per 1,000 admissions in 2000 vs 59.0 patients per 1,000 admissions in 1998), although the populations of patients were comparable. This decrease was the result of the decreased incidence of cases in which an isolate had a PFGE pattern identical to that of an isolate from a faucet (7.0 cases per 1,000 admissions in 2000, vs 23.6 per 1,000 admissions in 1998) or from another patient (6.5 cases per 1,000 admissions in 2000 vs 16.5 cases per 1,000 admissions in 1998), whereas the incidence of cases in which the isolate had a unique PFGE pattern remained nearly unchanged (13.1 cases per 1,000 admissions in 2000 vs 15.6 cases per 1,000 admissions in 1998). CONCLUSIONS These results suggest that infection control measures were effective in decreasing the rate of P. aeruginosa colonization and infection in ICU patients, confirming that P. aeruginosa strains were of exogenous origin in a substantial proportion of patients during the preintervention period.

Relationship between transcutaneous C02 measurement and PAC02 during non invasive ventilation delivered because of hypercapnic acute respiratory failure

Non-invasive ventilation (NIV) is the first line supportive treatment in case of acute hypercapnic respiratory failure (AHRF). NIV efficacy is continuously monitored using clinical parameters (respiratory frequency, use of accessory respiratory muscles). The assessment of NIV efficacy however usually requires repeated blood gas analysis after 30 or 60 minutes of treatment. A reliable non-invasive technique to continuously monitor PaC02 during NIV could simplify this evaluation and allow an earlier adaptation of ventilator settings.

In neuro critical care, capnia can be optimally controlled using a closed-loop ventilation system based on end-tidal CO2 signal (intellivent-asv(®)): preliminary results of a prospective interventional study.

Introduction Both hypoand hypercapnia can be deleterious to brain injured patients. Due to the variability of CO2 production and elimination and to the unpredictable effects of ventilator settings changes, strict arterial CO2 partial pressure (PaCO2) control is difficult to obtain. Conceivably, using expired (end-tidal) CO2 as the input signal of closed-loop ventilation (Intellivent-ASV) should optimize CO2 control compared to manual ventilator setting changes based on PaCO2 measurements.