Hospital-acquired pneumonia in the 21st century: a review of existing treatment options and their impact on patient care

Intravenous vs intravenous plus aerosolized colistin for treatment of ventilator-associated pneumonia - a matched case-control study in neonates

BACKGROUND

Recently intravenous (IV) and aerosolized (ASZ) colistin have been used for treating ventilator-associated pneumonia (VAP) due to colistin susceptible multidrug-resistant Gram-negative bacteria (MDR-GNB). Colistin has limited lung penetration. We compared the efficacy and safety of IV-alone versus IV+ASZ-colistin for treating VAP in neonates.

METHODS

This retrospective matched case-control study was performed at NICU of the Aga Khan University Hospital, Pakistan between January 2015 and December 2018. Sixteen neonates with MDR-GNB associated VAP received IV-ASZ-colistin and were matched for date of birth, gestational age, birth weight, Apgar score, antenatal steroid history, disease severity, and duration of mechanical ventilation with 16 control neonates who received IV-colistin alone.

RESULTS

Both groups had similar MDR-GNB isolates and Acinetobacter baumannii (78%) was the most common pathogen. No colistin-resistant strain was isolated. Duration of IV-colistin and concomitant antibiotics use was significantly (p < 0.05) shorter in the IV-ASZ-colistin group. Significantly (p < 0.05) higher clinical cure and microbial eradication, along with lower ventilatory requirements, mortality rate, and colistin induced nephrotoxicity and electrolyte imbalance was observed in the IV-ASZ-colistin group.

CONCLUSIONS

With better lung penetration, ASZ-colistin offers effective and safe microbiological and clinical benefits as adjunctive or alternate treatment of VAP due to colistin susceptible MDR-GNB in neonates.

Gram-negative bacteria as causative agents of ventilator-associated pneumonia and their respective resistance mechanisms

Ventilator-associated pneumonia (VAP) is a serious and common complication in patients admitted to intensive care unit (ICU) and contributes to mortality. Multidrug Gram-negative bacteria such as Acinetobacter baumannii, Pseudomonas aeruginosa, and Klebsiella pneumoniae are frequently associated with VAP in ICU. A prospective study was set up in three ICUs of the University Hospital Center Zagreb and one ICU in General Hospital Pula from September 2017 to March 2018. Antibiotic susceptibility was determined by broth microdilution method. Production of extended-spectrum β-lactamases (ESBLs) was determined by double-disk synergy test and carbapenemases by Hodge and carbapenem inactivation method (CIM). The genes encoding ESBLs, carbapenemases of class A, B and D and qnr genes were determined by PCR. In total 97 Gram-negative bacteria isolates were analyzed. P. aeruginosa demonstrated high resistance rates for imipenem and meropenem with 74% and 68% of resistant strains, respectively. Moderate resistance rates were observed for ceftazidime andpiperacillin/tazobactam, ciprofloxacin and gentamicin (44%). All except three A. baumannii isolates, were resistant to carbapenems and to all other antibiotics apart from colistin and amikacin. Eight A. baumannii isolates were positive for bla_OXA-23 and 12 for bla_OXA-24 genes. Four K. pneumoniae and two E. cloacae strains were ESBL positive and harboured group 1 of CTX-M β-lactamases. Three P. mirabilis strains were positive for plasmid-mediated ampC β-lactamase of CMY family. Two carbapenem-resistant K. pneumoniae harboured OXA-48 and one carbapenem-resistant E. cloacae VIM-1. A high proportion of multidrug-resistant P. aeruginosa, K. pneumoniae and extensively resistant A. baumannii was reported. Acquired resistance mechanisms, mainly production of carbapenemases and ESBLs were dominant in A. baumannii and K. pneumoniae, respectively. Resistance of P. aeruginosa isolates was more likely due to upregulation of efflux pumps or porin loss. A marked diversity of β-lactamases was identified in Enterobacteriaceae.

Treatment preferences in Turkey for open fracture of the tibial diaphysis

OBJECTIVE

The purpose of this study was to investigate different treatment methods employed by orthopedic surgeons for open tibial fracture in adults.

METHODS

Survey of 12 questions regarding treatment of open tibial fracture was conducted with 285 orthopedics and traumatology specialists in Turkey in personal interviews and using web-based technique.

RESULTS

Of all survey participants, 99.6% responded that tetanus prophylaxis is necessary emergency procedure in cases of adult open tibial diaphysis fracture. In addition, 96.5% considered antibiotics administration necessary, 85.6% also selected irrigation with saline, 55.4% included debridement, and 45.3% temporary fixation. Only 4 (1.3%) respondents did not use aminoglycoside antibiotics. While 29.8% of those surveyed preferred external fixator as a definitive treatment method, 75.8% use intramedullary nail and 13.7% preferred plate method.

CONCLUSION

A wide variation was observed among orthopedics and traumatology specialists in Turkey regarding treatment of open tibial diaphysis fracture in adults. Data obtained from this study together with the available literature may be useful to further develop therapeutic approaches.

Current Practice in the Management of Open Fractures Among Orthopaedic Trauma Surgeons. Part A: Initial Management. A Survey of Orthopaedic Trauma Surgeons

OBJECTIVES

Open fractures are one of the injuries with the highest rate of infection that orthopaedic trauma surgeons treat. The main purpose of this survey was to determine current practice and practice variation among Orthopaedic Trauma Association (OTA) members and make treatment recommendations based on previously published resources.

DESIGN

Survey.

SETTING

Web-based survey.

PARTICIPANTS

Three hundred seventy-nine orthopaedic trauma surgeons.

METHODS

A 15-item questionnaire-based study titled "OTA Open Fracture Survey" was constructed. The survey was delivered to all OTA membership categories. Different components of the data charts were used to analyze numerous aspects of open fracture management, focusing on parameters of initial and definitive treatment.

RESULTS

Eighty-six percent of participants responded that a period of time of less than 1 hour is the optimal time to antibiotic administration after identification of open fracture. Despite concerns with nephrotoxicity, 24.0%-76.3% of respondents reported the use of aminoglycosides in management of open fractures. A little over half of survey respondents continue antibiotics until next debridement in wounds that were not definitively closed after initial debridement and stabilization.

CONCLUSIONS

Rapid administration of antibiotics in open fracture management is important. Aminoglycoside use is still prevalent despite evidence questioning efficacy and toxicity concerns. Time to debridement of open fractures is controversial among OTA members. Antibiotic administration is commonly continued >48 hours despite concerns raised by Surgical Infection Society and The Eastern Association of the Surgery of Trauma. Regarding study logistics, survey participation reminders should be used when conducting this type of study as it can increase data accrual by 50%.

LEVEL OF EVIDENCE

Therapeutic Level V. See Instructions for Authors for a complete description of levels of evidence.

Management of bacterial infections in cirrhosis

Bacterial infections are very frequent in advanced cirrhosis and become the first cause of death of these patients. Despite numerous experimental data and significant advances in the understanding of the pathogenesis of sepsis in cirrhosis, the outcome remains poor. Classical diagnostic parameters such as C-reactive protein and SIRS criteria have less diagnostic capacity in the cirrhotic population, often delaying the diagnosis and the management of bacterial infection. Prompt and appropriate empirical antibiotic treatment of infection and early resuscitation of patients with severe sepsis or septic shock are essential in determining patient's outcome. A strategy of careful restriction of prophylactic antibiotics to the high-risk populations could reduce the spread of multidrug resistant bacteria. This review is focused on the currently recommended diagnostic, therapeutic and prophylactic strategies for bacterial infections in the cirrhotic population.

Guideline-adherent initial intravenous antibiotic therapy for hospital-acquired/ventilator-associated pneumonia is clinically superior, saves lives and is cheaper than non guideline adherent therapy

INTRODUCTION

Hospital-acquired pneumonia (HAP) often occurring as ventilator-associated pneumonia (VAP) is the most frequent hospital infection in intensive care units (ICU). Early adequate antimicrobial therapy is an essential determinant of clinical outcome. Organisations like the German PEG or ATS/ IDSA provide guidelines for the initial calculated treatment in the absence of pathogen identification. We conducted a retrospective chart review for patients with HAP/VAP and assessed whether the initial intravenous antibiotic therapy (IIAT) was adequate according to the PEG guidelines.

MATERIALS AND METHODS

We collected data from 5 tertiary care hospitals. Electronic data filtering identified 895 patients with potential HAP/VAP. After chart review we finally identified 221 patients meeting the definition of HAP/VAP. Primary study endpoints were clinical improvement, survival and length of stay. Secondary endpoints included duration of mechanical ventilation, total costs, costs incurred on the intensive care unit (ICU), costs incurred on general wards and drug costs.

RESULTS

We found that 107 patients received adequate initial intravenous antibiotic therapy (IIAT) vs. 114 with inadequate IIAT according to the PEG guidelines. Baseline characteristics of both groups revealed no significant differences and good comparability. Clinical improvement was 64% over all patients and 82% (85/104) in the subpopulation with adequate IIAT while only 47% (48/103) inadequately treated patients improved (p< 0.001). The odds ratio of therapeutic success with GA versus NGA treatment was 5.821 (p<0.001, [95% CI: 2.712-12.497]). Survival was 80% for the total population (n = 221), 86% in the adequately treated (92/107) and 74% in the inadequately treated subpopulation (84/114) (p = 0.021). The odds ratio of mortality for GA vs. NGA treatment was 0.565 (p=0.117, [95% CI: 0.276-1.155]). Adequately treated patients had a significantly shorter length of stay (LOS) (23.9 vs. 28.3 days; p = 0.022), require significantly less hours of mechanical ventilation (175 vs. 274; p = 0.001), incurred lower total costs (EUR 28,033 vs. EUR 36,139, p = 0.006) and lower ICU-related costs (EUR 13,308 vs. EUR 18,666, p = 0.003). Drug costs for the hospital stay were also lower (EUR 4,069 vs. EUR 4,833) yet not significant. The most frequent types of inadequate therapy were monotherapy instead of combination therapy, wrong type of penicillin and wrong type of cephalosporin.

DISCUSSION

These findings are consistent with those from other studies analyzing the impact of guideline adherence on survival rates, clinical success, LOS and costs. However, inadequately treated patients had a higher complicated pathogen risk score (CPRS) compared to those who received adequate therapy. This shows that therapy based on local experiences may be sufficient for patients with low CPRS but inadequate for those with high CPRS. Linear regression models showed that single items of the CPRS like extrapulmonary organ failure or late onset had no significant influence on the results.

CONCLUSION

Guideline-adherent initial intravenous antibiotic therapy is clinically superior, saves lives and is less expensive than non guideline adherent therapy. Using a CPRS score can be a useful tool to determine the right choice of initial intravenous antibiotic therapy. The net effect on the German healthcare system per year is estimated at up to 2,042 lives and EUR 125,819,000 saved if guideline-adherent initial therapy for HAP/VAP were established in all German ICUs.

Health care-associated pneumonia

Traditionally, pneumonia developing in patients who receive health care services in the outpatient environment, such as nursing homes, long-term care facilities, and dialysis centers, has been classified and treated as community-acquired pneumonia (CAP). Recent studies, however, have shown that this type of infection, known as health care-associated pneumonia (HCAP) is distinct from CAP in terms of its epidemiology and etiology, and increases the risk for infection with multidrug-resistant (MDR) pathogens. A review of available clinical data about HCAP was conducted to determine effective empiric treatment strategies and improve clinical outcomes. Analysis of multi-institutional clinical data showed that mortality associated with HCAP is higher than with CAP, suggesting that patients with HCAP may have been treated as hospitalized patients with CAP and received inappropriate initial empiric antibiotic treatment. All patients presenting to the hospital with suspected HCAP or CAP should be evaluated for their underlying risk of infection with MDR pathogens. Because HCAP may be similar to hospital-acquired pneumonia (HAP) both clinically and etiologically, it should be treated as HAP until culture data become available. A greater recognition of HCAP as a new class of pneumonia with a distinct epidemiologic, microbiologic, and clinical profile should lead physicians to initiate appropriate empiric antibiotic therapy more often, thereby improving the likelihood for optimal clinical outcomes and patient care.

Pneumonia

Hospital-acquired pneumonia (HAP) is usually caused by bacterial, viral, or fungal pathogens that occur ≥48 h after hospital admission.^1,2 Overall, more than 80% of HAP episodes are related to invasive airway management (in patients with endotracheal intubation or tracheostomy) with mechanical ventilation, which is known as ventilator-associated pneumonia (VAP).³ VAP is defined as pneumonia developing more than 48 h after intubation and mechanical ventilation. Healthcare-associated pneumonia (HCAP) is part of the continuum of pneumonia, which includes patients who were hospitalized in an acute-care hospital for ≥2 days within 90 days of the infection; resided in a long-term care facility; received recent intravenous antibiotic therapy, chemotherapy, or wound care within the past 30 days of the current infection; or attended a hospital or hemodialysis clinic.^1,2 Although this document focuses more on HAP and VAP, many of the principles are also relevant to the management of HCAP. HAP, VAP, and HCAP are the second most common nosocomial infections after urinary tract infection, but are the leading causes of mortality due to hospital-acquired infections.^4,5

A 7-year national survey on bacterial resistance in bronchoalveolar lavage from patients hospitalized in Argentina

The purpose of this study is to undertake a nationwide survey on bacterial resistance in bronchoalveolar lavage (BAL) from patients hospitalized in Argentina. A 2-month point prevalence study was conducted twice yearly (April-May and October-November) from 1997 to 2003 by 36 Argentinean centers. Antimicrobial susceptibility data of the potential pathogens recovered from the BAL (samples containing <1% of squamous epithelial cells and bacterial counts >or=10(4) CFU/mL) of inpatients (i.e., >or=48-h hospital length of stay) with suspected hospital-acquired pneumonia (HAP) were collected on a computerized system (SIR) described previously. The survey was split into 2 periods for comparison purposes, 1997 to 2000 and 2001 to 2003. A total of 752 organisms were included. Staphylococcus aureus was the most frequent species, followed by Acinetobacter spp. and Pseudomonas aeruginosa. In both periods, more than a half of the Klebsiella pneumoniae strains displayed a phenotype of extended-spectrum beta-lactamase producer. A doubling of imipenem-resistant Acinetobacter frequency was shown from the 1st period to the 2nd one (25-48%). More than two-thirds of the S. aureus strains proved to be methicillin resistant in both periods, and a pronounced decrease of resistance rates to trimethoprim/sulfamethoxazole and rifampin was shown in the 2nd period. The present study shows the worrisome increasing bacterial resistance in BAL samples to most available antimicrobial options for treating patients with suspected HAP. Variations over time support the need for systematic tailored surveillance and compel us to establish a rational usage of antimicrobial agents in our country.