A large-scale public health emergency, such as a severe influenza pandemic, can generate large numbers of critically ill patients in a short time. We modeled the number of mechanical ventilators that could be used in addition to the number of hospital-based ventilators currently in use.

We identified key components of the health care system needed to deliver ventilation therapy, quantified the maximum number of additional ventilators that each key component could support at various capacity levels (ie, conventional, contingency, and crisis), and determined the constraining key component at each capacity level.

Our study results showed that US hospitals could absorb between 26,200 and 56,300 additional ventilators at the peak of a national influenza pandemic outbreak with robust pre-pandemic planning.

The current US health care system may have limited capacity to use additional mechanical ventilators during a large-scale public health emergency. Emergency planners need to understand their health care systems’ capability to absorb additional resources and expand care. This methodology could be adapted by emergency planners to determine stockpiling goals for critical resources or to identify alternatives to manage overwhelming critical care need. (Disaster Med Public Health Preparedness. 2015;9:634–641)

Information on surges in critical care services including mechanical ventilator use during seasonal influenza outbreaks is limited. To potentially facilitate preparedness plans for future pandemics, we retrospectively quantitated surges in all-cause mechanical ventilator use during peak influenza for 12 consecutive years in all certified hospitals in Maryland.

Influenza testing data obtained for the Centers for Disease Control and Protection, Health and Human Services region 3, included defined peak influenza outbreak periods (PIOP), non-influenza time periods (non-ITP), and proportions of circulating influenza types for all study years. Procedure codes for mechanical ventilator use and diagnostic codes for medically attended acute respiratory illness (MAARI) were reviewed for every Maryland hospitalization. Daily counts of hospitalizations associated with ventilator use or MAARI during PIOP compared to non-ITP were analyzed using Poisson regression adjusted for month and year.

Ventilator use increased during PIOP by 7% (95% CI, 5-10) over non-ITP (P < .0001) for all study years. These annual surges correlated with influenza season intensity, as measured by MAARI-related hospitalizations (correlation coefficient = 0.91, P < .0001).

Surges in ventilator use were temporally associated with PIOP and were positively correlated with influenza season intensity, as measured by hospitalizations associated with acute respiratory illness. This information may assist resource planning for future pandemics. (Disaster Med Public Health Preparedness. 2014;x:1-7)

To quantify the association between admission to an intensive care unit (ICU) room most recently occupied by a patient positive for extended-spectrum β-lactamase (EBSL)-producing gram-negative bacteria and acquisition of infection or colonization with that pathogen.

Retrospective cohort study.

The study included patients admitted to medical and surgical ICUs of an academic medical center between September 1, 2001, and June 30, 2009.

Perianal surveillance cultures were obtained at admission to the ICU, weekly, and at discharge from the ICU. Patients were included if they had culture results that were negative for ESBL-producing gram-negative bacteria at ICU admission and had an ICU length of stay longer than 48 hours. Pulsed-field gel electrophoresis (PFGE) was performed on ESBL-positive isolates from patients who acquired the same bacterial species (eg, Klebsiella species or Escherichia coli) as the previous room occupant.

Among 9, 371 eligible admissions (7, 651 unique patients), 267 (3%) involved patients who acquired an ESBL-producing pathogen in the ICU; of these patients, 32 (12%) were hospitalized in a room in which the prior occupant had been positive for ESBL. Logistic regression results suggested that the prior occupant's ESBL status was not significantly associated with acquisition of an ESBL-producing pathogen (adjusted odds ratio, 1.39 [95% confidence interval, 0.94-2.08]) after adjusting for colonization pressure and antibiotic exposure in the ICU. PFGE results suggested that 6 (18%) of 32 patients acquired a bacterial strain that was the same as or closely related to the strain obtained from the prior occupant.

These data suggest that environmental contamination may not play a substantial role in the transmission of ESBL-producing pathogens among ICU patients. Intensifying environmental decontamination may be less effective than other interventions in preventing transmission of ESBL-producing pathogens.

Colonization pressure is an important infection control metric. The aim of this study was to describe the definition and measurement of and adjustment for colonization pressure in nosocomial-acquisition risk factor studies of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and Clostridium difficile.

We performed a computerized search of studies of nosocomial MRSA, VRE, and C. difficile acquisition published before July 1, 2009, through MEDLINE. Studies were included if a study outcome was MRSA, VRE, or C. difficile acquisition; the authors identified risk factors associated with MRSA, VRE, or C. difficile acquisition; and the study measured colonization pressure.

The initial MEDLINE search yielded 505 articles. Sixty-six of these were identified as studies of nosocomial MRSA, VRE, or C. difficile acquisition; of these, 18 (27%) measured colonization pressure and were included in the final review. The definition of colonization pressure varied considerably between studies: the proportion of MRSA- or VRE-positive patients (5 studies), the proportion of MRSA- or VRE-positive patient-days (6 studies), or the total or mean number of MRSA-, VRE-, or C. difficile-positive patients or patient-days (7 studies) in the unit over periods of varying length. In 10 of 13 studies, colonization pressure was independently associated with MRSA, VRE, or C. difficile acquisition.

There is a need for a simple and consistent method to quantify colonization pressure in both research and routine clinical care to accurately assess the effect of colonization pressure on cross-transmission of antibiotic-resistant bacteria.