Guidelines for the Management of Adults with Hospital-acquired, Ventilator-associated, and Healthcare-associated Pneumonia

Bloodstream infections occurring in persons residing in the community, regardless of whether those persons have been receiving health care in an outpatient facility, have traditionally been categorized as community-acquired infections. To develop a new classification scheme for bloodstream infections that distinguishes among community-acquired, health care-associated, and nosocomial infections. Prospective observational study. One academic medical center and two community hospitals. All adult patients admitted to the hospital with bloodstream infection. Demographic characteristics, living arrangements before hospitalization, comorbid medical conditions, factors predisposing to bloodstream infection, date of hospitalization, dates and number of positive blood cultures, results of microbiological susceptibility testing, dates of hospital discharge or death, and mortality rates at 3 to 6 months of follow-up. 504 patients with bloodstream infections were enrolled; 143 (28%) had community-acquired bloodstream infections, 186 (37%) had health care-associated bloodstream infections, and 175 (35%) had nosocomial bloodstream infections. Of the 186 patients with health care-associated bloodstream infection, 29 resided in a nursing home, 64 were receiving home health care, 78 were receiving intravenous or intravascular therapy at home or in a clinic, and 117 had been hospitalized in the 90 days before their bloodstream infection. Cancer was more common in patients with health care-associated or nosocomial bloodstream infection than in patients with community-acquired bloodstream infection. Intravascular devices were the most common source of health care-associated and nosocomial infections, and Staphylococcus aureus was the most frequent pathogen in these types of infections. Methicillin-resistant S. aureus occurred with similar frequency in the groups with health care-associated infection (52%) and nosocomial infection (61%) but was uncommon in the group with community-acquired bloodstream infection (14%) (P = 0.001). Mortality rate at follow-up was greater in patients with health care-associated infection (29% versus 16%; P = 0.019) or nosocomial infection (37% versus 16%; P < 0.001) than in patients with community-acquired infection. Health care-associated bloodstream infections are similar to nosocomial infections in terms of frequency of various comorbid conditions, source of infection, pathogens and their susceptibility patterns, and mortality rate at follow-up. A separate category for health care-associated bloodstream infections is justified, and this new category will have obvious implications for choices about empirical therapy and infection-control surveillance.

It is uncertain whether lower levels of staffing by nurses at hospitals are associated with an increased risk that patients will have complications or die. We used administrative data from 1997 for 799 hospitals in 11 states (covering 5,075,969 discharges of medical patients and 1,104,659 discharges of surgical patients) to examine the relation between the amount of care provided by nurses at the hospital and patients' outcomes. We conducted regression analyses in which we controlled for patients' risk of adverse outcomes, differences in the nursing care needed for each hospital's patients, and other variables. The mean number of hours of nursing care per patient-day was 11.4, of which 7.8 hours were provided by registered nurses, 1.2 hours by licensed practical nurses, and 2.4 hours by nurses' aides. Among medical patients, a higher proportion of hours of care per day provided by registered nurses and a greater absolute number of hours of care per day provided by registered nurses were associated with a shorter length of stay (P=0.01 and P<0.001, respectively) and lower rates of both urinary tract infections (P<0.001 and P=0.003, respectively) and upper gastrointestinal bleeding (P=0.03 and P=0.007, respectively). A higher proportion of hours of care provided by registered nurses was also associated with lower rates of pneumonia (P=0.001), shock or cardiac arrest (P=0.007), and "failure to rescue," which was defined as death from pneumonia, shock or cardiac arrest, upper gastrointestinal bleeding, sepsis, or deep venous thrombosis (P=0.05). Among surgical patients, a higher proportion of care provided by registered nurses was associated with lower rates of urinary tract infections (P=0.04), and a greater number of hours of care per day provided by registered nurses was associated with lower rates of "failure to rescue" (P=0.008). We found no associations between increased levels of staffing by registered nurses and the rate of in-hospital death or between increased staffing by licensed practical nurses or nurses' aides and the rate of adverse outcomes. A higher proportion of hours of nursing care provided by registered nurses and a greater number of hours of care by registered nurses per day are associated with better care for hospitalized patients.

Pseudomonas aeruginosa carries multiresistance plasmids less often than does Klebsiella pneumoniae, develops mutational resistance to cephalosporins less readily than Enterobacter species, and has less inherent resistance than Stenotrophomonas maltophilia. What nevertheless makes P. aeruginosa uniquely problematic is a combination of the following: the species' inherent resistance to many drug classes; its ability to acquire resistance, via mutations, to all relevant treatments; its high and increasing rates of resistance locally; and its frequent role in serious infections. A few isolates of P. aeruginosa are resistant to all reliable antibiotics, and this problem seems likely to grow with the emergence of integrins that carry gene cassettes encoding both carbapenemases and amikacin acetyltransferases.