Effect of adequate single-drug versus combination antimicrobial therapy on mortality in Pseudomonas aeruginosa bloodstream infections. A post hoc analysis of a prospective cohort.

Clin Infect Dis. 2013 Apr 11;

Authors: Peña C, Suarez C, Ocampo-Sosa A, Murillas J, Almirante B, Pomar V, Aguilar M, Granados A, Calbo E, Rodríguez-Baño J, Rodríguez F, Tubau F, Oliver A, Martínez-Martínez L, for the Spanish Network for Research in Infectious Diseases (REIPI)

Abstract
Background. Empirical combination therapy is recommended for patients with known or suspected Pseudomonas aeruginosa (PA) infections as a means to decrease the likelihood of administering inadequate antimicrobial treatment, to prevent the emergence of resistance, and to achieve a possible additive or even synergistic effect. Methods. We performed a post-hoc analysis of patients with PA bloodstream infections from a published prospective cohort. Mortality was compared in patients treated with adequate empirical and definitive combination therapy (AECT, ADCT), and adequate empirical and definitive single-drug therapy (AESD, ADSD). Confounding was controlled by Cox regression analysis, and a propensity score for receiving AECT or ADCT was also used. Results. The final cohort comprised 593 patients with a single episode of PA bacteremia. The 30-day mortality was 30% (176 patients); 76 patients (13%) died during the first 48 hours. The unadjusted probabilities of survival until day 30 were 69.4% (95% confidence interval [CI]: 59.1-81.6) for the patients which receiving AECT, 73.5% (95% CI: 68.4-79.0) for the AESD group, and 66.7% (95% CI: 61.2-72.7) for patients who received inadequate empirical therapy (P=0.17, log-rank test). After adjustment for confounders, the AESD group (adjusted hazard ratio [aHR]: 1.17; 95%CI: 0.70-1.96; p=0.54) and patients who received ADSD (aHR: 1.34; 95%CI: 0.73-2.47 p=0.35) showed no association with 30-day mortality compared with the AECT and ADCT groups respectively. Conclusions. These results suggests that treatment with combination antimicrobial therapy did not reduce the mortality risk compared with single-drug therapy in PA bloodstream infections.

PMID: 23580739 [PubMed - as supplied by publisher]

Discontinuation of Contact Precautions for Methicillin-Resistant Staphylococcus aureus (MRSA): A Randomized Controlled Trial Comparing Passive and Active Screening with Culture and Polymerase Chain Reaction.

Clin Infect Dis. 2013 Apr 9;

Authors: Shenoy ES, Kim J, Rosenberg ES, Cotter JA, Lee H, Walensky RP, Hooper DC

Abstract
Background. There have been no randomized controlled trials comparing active and passive screening for documenting clearance of colonization with methicillin-resistant Staphylococcus aureus (MRSA). We compared the efficacy of active and passive screening using both culture and commercial polymerase chain reaction (PCR) for documentation of MRSA clearance and discontinuation of MRSA Contact Precautions (CP). Methods. Inpatients with a history of MRSA infection or colonization enrolled between December 2010 and September 2011 were randomized to either passive (Non-Intervention Arm; n=202; observation with local standard of care [SOC]) or active screening (Intervention Arm; n=405; study staff screened using culture and commercial polymerase chain reaction (PCR).The primary outcome was discontinuation of CP by trial arm based on three negative cultures. In the Intervention Arm, sensitivity, specificity, and positive and negative predictive value of the first PCR were compared to cultures. Results. CP were discontinued significantly more often (rate ratio [RR], 4.1; 95% confidence interval [CI], 2.3%-7.1%) in the Intervention Arm, including in an intent-to-screen analysis (RR, 2.6; 95% CI, 1.5%-4.7%).The first PCR, compared to three cultures, detected MRSA with a sensitivity of 93.9% (95% CI, 85.4%-97.6%), a specificity of 92.0% (95% CI, 85.9%-95.6%), a positive predictive value of 86.1% (95% CI, 75.9%-93.1%) and a negative predictive value of 96.6% (95% CI, 91.6%-99.1%). Conclusions. Compared to passive screening using culture methods, active screening resulted in discontinuation of MRSA CP at a significantly higher frequency. Active screening with a single PCR would significantly increase the completion of the screening process.

PMID: 23572482 [PubMed - as supplied by publisher]

Understanding the Determinants of Antimicrobial Prescribing within hospitals: The role of 'Prescribing Etiquette'

Clin Infect Dis. 2013 Apr 9;

Authors: Charani E, Castro-Sanchez E, Sevdalis N, Kyratsis Y, Drumright L, Shah N, Holmes A

Abstract
Background. There is limited knowledge of the key determinants of antimicrobial prescribing behaviours (APB) in hospitals. An understanding of these determinants is required for the successful design, adoption, and implementation of quality improvement interventions in antimicrobial stewardship programmes. Methods. Qualitative semi-structured interviews were conducted with doctors (10), pharmacists (10), nurses and midwives (19) in four hospitals in London. Interviews were conducted until thematic saturation was reached. Thematic analysis was applied to the data to identify the key determinants of antimicrobial prescribing behaviours. Results. The APB of health care professionals is governed by a set of cultural rules. Antimicrobial prescribing is performed in an environment where the behaviour of clinical leaders or seniors influences practice of junior doctors. Senior doctors consider themselves exempt from following policy and practice within a culture of perceived autonomous decision making which relies more on personal knowledge and experience than formal policy. Prescribers identify with the clinical groups in which they work and adjust their APB according to the prevailing practice within these groups. A culture of 'non-interference' in the antimicrobial prescribing practice of peers prevents intervention into prescribing of colleagues. These sets of cultural rules demonstrate the existence of a 'prescribing etiquette', which dominates the APB of healthcare professionals. Prescribing etiquette creates an environment in which professional hierarchy and clinical groups act as key determinants of APB. Conclusions. To influence the antimicrobial prescribing of individual healthcare professionals, interventions need to address prescribing etiquette and use clinical leadership within existing clinical groups to influence practice.

PMID: 23572483 [PubMed - as supplied by publisher]