Christine Campbell Reardon

Propylene glycol toxicity in a patient receiving intravenous diazepam.

To the Editor: Alcohol withdrawal is a common problem among hospitalized patients and is frequently treated with intravenous diazepam. Propylene glycol is a solvent in which diazepam is often disso...

Phagocytosis and growth inhibition of Cryptococcus neoformans by human alveolar macrophages : effects of HIV-1 infection

Objective The purpose of this study was to investigate the in vitro processing of Cryptococcus neoformans by human alveolar macrophages from HIV-seropositive individuals compared with HIV-seronegative individuals. Design and methods Bronchoalveolar lavage (BAL) was performed on smoking and nonsmoking HIV-seropositive and seronegative volunteers. Lavage cells from the four groups were challenged in vitro with C. neoformans and assessed for fungal binding, phagocytosis, and growth inhibition. Results The results indicated that BAL cells from the smoking HIV-infected group had increased fungistatic activity compared with HIV-seronegative smokers (mean percentage growth inhibition ± SD, 77.5 ± 14.2 versus 59.1 ± 16.6%; P= 0.015). However, late-staged HIV-infected patients (Centers for Disease Control and Prevention class C3) were found to have decreased fungistasis compared with early stage A patients (63.8 ± 11.1 versus 83.0 ±2.2%; P <0.05). BAL cells recovered from HIV-seronegative smoking volunteers demonstrated reduced fungistatic activity when compared with BAL cells from HIV-seronegative nonsmokers (56.8 ± 8.8 versus 83.0 ±2.2%; P < 0.001). Smoking also induced a decrease in internalization of C. neoformans by alveolar macrophages as assessed by confocal laser microscopy in both HIV-seronegative and HIV-infected groups. Conclusion We conclude that BAL cells from early-stage HIV-1-infected individuals do not have an intrinsic defect in fungistasis of C. neoformans. In fact, it appears that BAL cells from HIV-seropositive people are activated for fungistasis in early HIV infection, although fungistatic activity declines as the disease progresses. Incidentally noted was the finding that smoking decreases the internalization of C. neoformans in both HIV-infected and HIV-seronegative individuals, suggesting the possibility that smoking might enhance the susceptibility to cryptococcosis.

Epidemiology of ventilator-associated pneumonia in a long-term acute care hospital.

OBJECTIVE To characterize the epidemiology and microbiology of ventilator-associated pneumonia (VAP) in a long-term acute care hospital (LTACH). DESIGN Retrospective study of prospectively identified cases of VAP. SETTING Single-center, 207-bed LTACH with the capacity to house 42 patients requiring mechanical ventilation, evaluated from April 1, 2006, through January 31, 2008. METHODS Data on the occurrence of VAP were collected prospectively as part of routine infection surveillance at Radius Specialty Hospital. After March 2006, Radius Specialty Hospital implemented a bundle of interventions for the prevention of VAP (hereafter referred to as the VAP-bundle approach). A case of VAP was defined as a patient who required mechanical ventilation at Radius Specialty Hospital for at least 48 hours before any symptoms of pneumonia appeared and who met the Centers for Disease Control and Prevention criteria for VAP. Sputum samples were collected from a tracheal aspirate if there was clinical suspicion of VAP, and these samples were semiquantitatively cultured. RESULTS During the 22-month study period, 23 cases of VAP involving 19 patients were associated with 157 LTACH admissions (infection rate, 14.6%), corresponding to a rate of 1.67 cases per 1,000 ventilator-days, which is a 56% reduction from the VAP rate of 3.8 cases per 1,000 ventilator-days reported before the implementation of the VAP-bundle approach (P< .001). Microbiological data were available for 21 (91%) of 23 cases of VAP. Cases of VAP in the LTACH were frequently polymicrobial (mean number +/- SD, 1.78+/-1.0 pathogens per case of VAP), and 20 (95%) of 21 cases of VAP had at least 1 pathogen (Pseudomonas species, Acinetobacter species, gram-negative bacilli resistant to more than 3 antibiotics, or methicillin-resistant Staphylococcus aureus) cultured from a sputum sample. LTACH patients with VAP were more likely to have a neurological reason for ventilator dependence, compared with LTACH patients without VAP (69.6% of cases of VAP vs 39% of cases of respiratory failure; P= .014). In addition, patients with VAP had a longer length of LTACH stay, compared with patients without VAP (median length of stay, 131 days vs 39 days; P= .002). In 6 (26%) of 23 cases of VAP, the patient was eventually weaned from use of mechanical ventilation. Of the 19 patients with VAP, 1 (5%) did not survive the LTACH stay. CONCLUSIONS The VAP rate in the LTACH is lower than the VAP rate reported in acute care hospitals. Cases of VAP in the LTACH were frequently polymicrobial and were associated with multidrug-resistant pathogens and increased length of stay. The guidelines from the Centers for Disease Control and Prevention that are aimed at reducing cases of VAP appear to be effective if applied in the LTACH setting.

Use of airway pressure release ventilation is associated with a reduced incidence of ventilator-associated pneumonia in patients with pulmonary contusion.

BACKGROUND Past studies suggest that airway pressure release ventilation (APRV) is associated with reduced sedative requirements and increased recruitment of atelectatic lung, two factors that might reduce the risk for ventilator-associated pneumonia (VAP). We investigated whether APRV might be associated with a decreased risk for VAP in patients with pulmonary contusion. MATERIALS Retrospective cohort study. RESULTS Of 286, 64 (22%) patients requiring mechanical ventilation for >48 hours met criteria for pulmonary contusion and were the basis for this study. Subjects with pulmonary contusion had a significantly higher rate of VAP than other trauma patients, [VAP rate contusion patients: 18.3/1,000, non-contusion patients: 7.7/1,000, incidence rate ratio 2.37 (95% confidence interval [CI], 1.11-4.97), p=0.025]. Univariate analysis showed that APRV (hazard ratio, 0.15 [0.03-0.72; p=0.018]) was associated with a decreased incidence of VAP. Cox proportional hazards regression, using propensity scores for APRV to control for confounding, supported a protective effect of APRV from VAP (hazard ratio, 0.10 [95% CI, 0.02-0.58]; p=0.01). Pao2/FiO2 ratios were higher during APRV compared with conventional ventilation (p<0.001). Subjects attained the goal Sedation Agitation Score for an increased percentage of time during APRV (median [interquartile range (IQR)] 72.7% [33-100] of the time) compared with conventional ventilation (47.2% [0-100], p=0.044), however, dose of sedatives was not different between these subjects. APRV was not associated with hospital mortality (odds ratio 0.57 [95% CI, 0.06-5.5]; p=0.63) or ventilator-free days (No APRV 15.4 vs. APRV 13.7 days, p=0.49). CONCLUSION Use of APRV in patients with pulmonary contusion is associated with a reduced risk for VAP.

Outcomes of a ventilator-associated pneumonia bundle on rates of ventilator-associated pneumonia and other health care-associated infections in a long-term acute care hospital setting

Long-term trends in ventilator-associated pneumonia (VAP) rates, and other health care-associated infections, were examined prior to, during, and after introduction of a VAP bundle in a long-term acute care hospital setting. VAP incidence rate declined in a step-wise fashion and reached a null value. Incidence rates of bacteremia from any cause declined in a similar fashion. The incidence rates of vancomycin-resistant enterococci and methicillin-resistant Staphylococcus aureus colonization or infection rates also decreased, but that of Clostridium difficile infection did not. VAP in the long-term acute care hospital setting can be controlled over time with implementation of Centers for Disease Control and Prevention-based VAP bundle. This outcome also may decrease certain other health care-associated infections.