Prevalence and risk factors of methicillin-resistant Staphylococcus aureus colonization among critically ill hospitalized patients in a tertiary care center in Houston, Texas: an active surveillance pilot project

Evaluation of sedation-related medication errors in patients on contact isolation in the intensive care unit

BACKGROUND

Patients in intensive care units (ICUs) may be placed on contact isolation for meticillin-resistant Staphylococcus aureus (MRSA) colonization to prevent transmission. Prior studies suggest that isolated patients may receive substandard care compared with non-isolated patients. An optimal level of sedation is required to facilitate mechanical ventilation (MV) and to minimize adverse outcomes.

AIM

To determine if patients on MV and isolated for MRSA colonization are at increased risk of oversedation compared with non-isolated patients.

METHODS

Retrospective chart review of adult patients on MV who received an MRSA nasal polymerase chain reaction assay and sedation within 24 and 48 h of ICU admission, respectively. Endpoints included rate of inappropriate sedation, length of ICU stay, length of time on MV, and incidence of ventilator-associated complications.

FINDINGS

In total, 226 patients were included (114 MRSA positive, 112 MRSA negative). Baseline demographics were similar between the groups, with the exception of ICU admission diagnosis. Fifty-six (55%) isolated patients experienced inappropriate sedation compared with 49 (50%) non-isolated patients (P=0.482). Isolated patients spent longer in the ICU (10.4 vs 6.8 days, P=0.0006), longer on MV (8.98 vs 4.81 days, P<0.001), and required tracheostomies more frequently [37 (32%) vs 14 (13%), P=0.0003] than non-isolated patients.

CONCLUSIONS

Isolated patients were not at increased risk of oversedation compared with non-isolated patients. There was an association between the use of contact isolation for MRSA nares colonization and prolonged ICU stay and prolonged MV.

The prevalence and significance of methicillin-resistant Staphylococcus aureus colonization at admission in the general ICU Setting: a meta-analysis of published studies

OBJECTIVE

To estimate the prevalence and significance of nasal methicillin-resistant Staphylococcus aureus colonization in the ICU and its predictive value for development of methicillin-resistant S. aureus infection.

DATA SOURCES

MEDLINE and EMBASE and reference lists of all eligible articles.

STUDY SELECTION

Studies providing raw data on nasal methicillin-resistant S. aureus colonization at ICU admission, published up to February 2013. Analyses were restricted in the general ICU setting. Medical, surgical, and interdisciplinary ICUs were eligible. ICU studies referring solely on highly specialized ICUs populations and reports on methicillin-resistant S. aureus outbreaks were excluded.

DATA EXTRACTION

Two authors independently assessed study eligibility and extrapolated data in a blinded fashion. The two outcomes of interest were the prevalence estimate of methicillin-resistant S. aureus nasal colonization at admission in the ICU and the sensitivity/specificity of colonization in predicting methicillin-resistant S. aureus-associated infections.

DATA SYNTHESIS

Meta-analysis, using a random-effect model, and meta-regression were performed. Pooled data extracted from 63,740 evaluable ICU patients provided an estimated prevalence of methicillin-resistant S. aureus nasal colonization at admission of 7.0% (95% CI, 5.8-8.3). Prevalence was higher for North American studies (8.9%; 95% CI, 7.1-10.7) and for patients screened using polymerase chain reaction (14.0%; 95% CI, 9.6-19). A significant per year increase in methicillin-resistant S. aureus colonization was also noted. In 17,738 evaluable patients, methicillin-resistant S. aureus infections (4.1%; 95% CI, 2.0-6.8) developed in 589 patients. The relative risk for colonized patients was 8.33 (95% CI, 3.61-19.20). Methicillin-resistant S. aureus nasal carriage had a high specificity (0.96; 95% CI, 0.90-0.98) but low sensitivity (0.32; 95% CI, 0.20-0.48) to predict methicillin-resistant S. aureus-associated infections, with corresponding positive and negative predictive values at 0.25 (95% CI, 0.11-0.39) and 0.97 (95% CI, 0.83-1.00), respectively.

CONCLUSIONS

Among ICU patients, 5.8-8.3% of patients are colonized by methicillin-resistant S. aureus at admission, with a significant upward trend. Methicillin-resistant S. aureus colonization is associated with a more than eight-fold increase in the risk of associated infections during ICU stay, and methicillin-resistant S. aureus infection develops in one fourth of patients who are colonized with methicillin-resistant S. aureus at admission to the ICU.

Antibiotic resistance patterns in medical and surgical patients in a combined medical-surgical intensive care unit

PURPOSE

Studies have found different rates of antimicrobial resistance among patients in medical and surgical intensive care units (ICUs). We studied whether these differences were a function of geography or differences in the patient populations, by comparing resistance rates among bacteria isolated from a combined medical/surgical ICU.

MATERIALS AND METHODS

We retrospectively evaluated the results of bacterial cultures of each patient admitted to the ICU between February 2005 and September 2006. Data collection included patient demographics and culture and sensitivity results. Intensive care unit populations were compared using the Fisher exact test and the Student t test.

RESULTS

One hundred seventy-one medical and 94 surgical patients with positive cultures were studied. Organisms were grouped into 4 classes: Staphylococcus aureus, nonlactose fermenting gram-negative bacilli, Enterococcus species, and gram-negative enteric bacteria. In the 4 classes, no significant difference in antibiotic resistance was found between medical and surgical patients.

CONCLUSION

Reported differences in resistance patterns among bacteria cultured from medical and surgical patients may be due to geographic separation of the ICUs as opposed to differences in the patient characteristics. This study suggests that ICU-specific antibiograms remain a useful tool to guide the choice of antimicrobial therapy, even in medical/surgical ICUs.