Bacteremic Nosocomial Pneumonia: A 7-Year Experience in One Institution

doi:10.1378/chest.108.3.786

Chest

Volume 108, Issue 3, September 1995, Pages 786-788

https://doi.org/10.1378/chest.108.3.786 Get rights and content

Study object

To describe the epidemiology, microbiology, and outcome of nosocomial pneumonia with secondary bloodstream infection.

Design

Prospective cohort study.

Setting

Tertiary care Canadian teaching hospital.

Patients

Inpatients.

Measurement

All inpatient blood cultures were concurrently monitored over an 89 month period. Following chart review, patients experiencing nosocomial bloodstream infection due to pneumonia were identified. A standardized definition of pneumonia was used.

Results

One hundred forty-nine episodes occurred in 145 patients, 0.66/1,000 hospital admissions, 8.4% of all nosocomial bloodstream infections. No change in rate occurred in the study period. Fifty-four percent of episodes developed in one of seven ICUs.

Staphylococcus aureus

was the most frequently identified etiologic organism (27%). The ICU and non-ICU cases did not differ in etiology. No organism became more prevalent during the study period. Twenty percent of patients died within 1 week of first positive culture; episodes associated with Pseudomonas species had a much higher mortality rate (45%) than other infections (14%) (p=0.002). The ICU and non-ICU infections had a similar mortality rate.

Conclusion

Pneumonia is an important cause of nosocomial bloodstream infection, but it is not increasing in frequency or changing in etiology in our institution. The ICUs are a major contributor to this problem but have the same case short-term mortality rate and microbial etiology as non-ICU cases. Cases associated with Pseudomonas have a much higher mortality rate.

Section snippets

METHODS

The University of Alberta Hospital is a 700-bed tertiary care hospital and principal teaching facility of the University of Alberta. All standard forms of acute hospital care, including pediatrics, oncology, and transplantation (excluding bone marrow transplantation), are offered. The hospital has seven ICUs providing ventilator support and invasive hemodynamic monitoring: neonatal, pediatric, general medical/surgical, cardiac surgery, neurosurgery, burns, and coronary care. We have

RESULTS

There were 149 episodes of bacteremic nosocomial pneumonia in 145 patients in the 89 months of the study, representing 8.4% of 1,772 episodes of nosocomial bloodstream infection. For the 7 complete years of the survey, the infection rate was 0.66/1,000 hospital admissions and 0.06/1,000 patient days. Analyzed annually, a small increase occurred between 1987 (0.44/1,000 hospital admissions) and 1988 (0.68/1,000). Thereafter, the rate remained stable. However, the rate for nosocomial bloodstream

DISCUSSION

The major previous study on this subject was that published by Bryan and Reynolds¹³ in 1984. They found 172 episodes of bacteremic nosocomial pneumonia in four hospitals over a 5-year period, a rate of 0.5/1,000 hospital admissions. Our rate of 0.66/1,000 is similar but appears to be below the rate of 1.65/1,000 at the teaching Veterans Affairs facility included in their study. Despite the evidence from elsewhere¹⁷ and within our own institution that nosocomial bloodstream infections are

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Risk factors for hospital-acquired pneumonia outside the intensive care unit: A case-control study
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Information on clinical practice regarding the diagnosis of pneumonia in European intensive care units is limited. The aim of this study was to describe the spectrum of actual diagnostic practices in a large sample of European intensive care units.
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Twenty-seven intensive care units of nine European countries.
Consecutive patients requiring invasive mechanical ventilation for an admission diagnosis of pneumonia or receiving mechanical ventilation for >48 hrs irrespective of admission diagnosis.
None.
A total of 2,436 patients were evaluated; 827 were admitted with or developed nosocomial pneumonia (hospital-acquired pneumonia [HAP], 27.1%; ventilator-associated pneumonia [VAP], 56.2%; very early onset VAP, 16.7%). Mean age was 59.4 ± 18.1 yrs, 65.0% were men, and mean admission Simplified Acute Physiology Score II was 46.7 ± 17.1. Worsening oxygenation (76.8%), purulent/changing respiratory secretions (72.1%), and new temperature elevation (69.2%) were the most frequent clinical signs of nosocomial pneumonia. Etiological diagnosis was based on noninvasive respiratory specimens in 74.8% of episodes. Bronchoscopy was performed in 23.3% of episodes. Bronchoscopy performance, after adjustment by severity of illness, age, and type of hospital, were predicted by worsening oxygenation (odds ratio 2.03; 95% confidence interval, 1.27–3.24) and male sex (odds ratio 1.77; 95% confidence interval, 1.19–2.65). Definite cause was documented in 69.5% of nosocomial pneumonia cases. The most common isolates were Staphylococcus aureus (16.3% methicillin-sensitive S. aureus and 16.0% methicillin-resistant S. aureus), Pseudomonas aeruginosa (23.1%), and Acinetobacter baumannii (19.1%). Presence of nosocomial pneumonia significantly prolonged mean length of mechanical ventilation (10.3 days, p < .05) and mean intensive care unit length of stay (12.2 days, p < .05) in intensive care unit survivors. Mortality rate was 37.7% for nosocomial pneumonia vs. 31.6% for patients without pneumonia (p < .05).
Etiological diagnosis of nosocomial pneumonia in a large sample of European intensive care units was based mainly on noninvasive techniques. However, there was high variability in bronchoscopy use between the participating intensive care units.

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Chest

Clinical Investigations in Critical CareBacteremic Nosocomial Pneumonia: A 7-Year Experience in One Institution

Study object

Design

Setting

Patients

Measurement

Results

Staphylococcus aureus

Conclusion

Section snippets

METHODS

RESULTS

DISCUSSION

Crit Care Clin

Chest

Am J Infect Control

Nosocomial pneumonias.

Curr Opin Infect Dis

Major trends in the microbial etiology of nosocomial infection.

Am J Med

Bacteriology of hospital-acquired pneumonia.

Arch Intern Med

Nosocomial bacterial pneumonias.

Sem Respir Infect

ICU pneumonias: a multi-institutional study.

Crit Care Med

Clinical Investigations in Critical Care
Bacteremic Nosocomial Pneumonia: A 7-Year Experience in One Institution