Treatment outcomes of patients with non-bacteremic pneumonia caused by extensively drug-resistant Acinetobacter calcoaceticus-Acinetobacter baumannii complex isolates: Is there any benefit of adding tigecycline to aerosolized colistimethate sodium?

Abstract

Few therapeutic options exist for various infections caused by extensively drug-resistant Acinetobacter calcoaceticus-Acinetobacter baumannii (XDR-Acb) complex isolates, including pneumonia. This study investigated the clinical efficacy between aerosolized colistimethate sodium (AS-CMS, 2 million units thrice a day) treatment alone or in combination with standard-dose tigecycline (TGC) in patients with non-bacteremic pneumonia due to XDR-Acb, and explored the factors influencing patients' 30-day mortality.A 1:1 case (n = 106; receiving TGC plus AS-CMS) control (receiving AS-CMS alone with matching scores) observational study was conducted among adult patients with non-bacteremic XDR-Acb complex pneumonia in a Taiwanese medical center from January 2014 through December 2016. The clinically relevant data were retrospectively recorded. The primary endpoint was 30-day case fatality. Secondary endpoints investigated that if the co-morbidities, XDR-A. baumannii as a pneumonic pathogen, therapy-related factors, or airway colonization with colistin-resistant Acb negatively influenced the 14-day clinical condition of enrolled patients.A higher 30-day mortality rate was noted among the group receiving combination therapy (34.0% vs 22.6%; P = .17). The ≥7-day AS-CMS therapy successfully eradicated > 90% of airway XDR-Acb isolates. Nevertheless, follow-up sputum specimens from 10 (6.4% [10/156]) patients were colonized with colistin-resistant Acb isolates. After the conditional factors were adjusted by multivariate logistic analysis, the only factor independently predicting the 30-day case-fatality was the failure of treating XDR-Acb pneumonia at 14 days (adjusted odds ratio [aOR] = 38.2; 95% confidence interval [CI] = 9.96-142.29; P < .001). Cox proportional regression analysis found that chronic obstructive pulmonary disease (COPD) (adjusted hazard ratio [aHR] = 2.08; 95% CI = 1.05-4.10; P = .035), chronic renal failure (aHR = 3.00; 95% CI = 1.52-5.90; P = .002), non-invasive ventilation use (aHR = 2.68; 95% CI = 1.37-5.25; P = .004), and lack of TGC therapy (aHR = 0.52; 95% CI = 0.27-1.00; P = .049) adversely influenced the 14-day clinical outcomes. Conversely, the emergence of colistin-resistant Acb isolates in the follow-up sputum samples was not statistically significantly associated with curing or improving XDR-Acb pneumonia.In conclusion, aggressive pulmonary hygiene care, the addition of TGC, and corticosteroid dose tapering were beneficial in improving the 14-day patients' outcomes.

• Authors: Shio-Shin Jean, Tai-Chin Hsieh, Wen-Sen Lee, Po-Ren Hsueh, Chin-Wan Hsu, Carlos Lam
• Journal: Medicine (Medicine (Baltimore)) Vol. 97 Issue 39 Pg. e12278 (Sep 2018) ISSN: 1536-5964 [Electronic] United States
• PMID: 30278498 (Publication Type: Journal Article, Observational Study)

Chemical References

• Anti-Bacterial Agents
• Tigecycline
• colistinmethanesulfonic acid
• Minocycline
• Colistin

Topics

• Acinetobacter (drug effects, isolation & purification)
• Acinetobacter Infections (drug therapy, mortality)
• Adult
• Aged
• Aged, 80 and over
• Anti-Bacterial Agents (administration & dosage)
• Case-Control Studies
• Colistin (administration & dosage, analogs & derivatives)
• Drug Resistance, Multiple, Bacterial
• Drug Therapy, Combination
• Female
• Follow-Up Studies
• Humans
• Male
• Middle Aged
• Minocycline (administration & dosage, analogs & derivatives)
• Pneumonia (drug therapy, microbiology, mortality)
• Retrospective Studies
• Survival Rate
• Taiwan
• Tigecycline
• Treatment Outcome