Editorial commentary: Preventing aspiration pneumonia in high-risk nursing home residents: role of chlorhexidine-based oral care questioned again.

Pneumonia generally occurs following aspiration of microorganisms from the oral cavity or nasopharynx. Aspiration pneumonia is common in the nursing home population and is often associated with oropharyngeal dysphagia and regurgitation of gastric contents [1]. Dental plaque has been particularly studied as a source of bacteria that may cause respiratory infections. A study in Japan showed an association between periodontal disease and increased mortality from pneumonia [2]. Another study of 137 nursing home residents revealed that 58% had extensive oral needs, and 30% reported a severe impact on their oral health–related quality of life [3]. Inadequate oral care significantly increases the risk for developing pneumonia and, based on an elegant paper published almost a decade ago in this journal [4], is considered to be a modifiable risk factor. Several preliminary studies suggest that adequate oral hygiene using mouth rinses, toothpaste, and brushing, along with feeding in an upright position, would mitigate the risk of pneumonias attributed to aspiration. Studies from acute care support the role of chlorhexidine rinses and semirecumbent positioning to reduce aspiration pneumonia [5]. A recent systematic review assessed the effects of oral healthcare on the incidence of patients with ventilator-associated pneumonia receiving mechanical ventilation in intensive care units (ICUs) and showed that either chlorhexidine rinse or gel is associated with a 40% reduction in ventilatorassociated pneumonia in critically ill patients [6]. Another systematic review of randomized controlled trials focusing on aging populations revealed that oral hygiene had positive preventive effects on pneumonia and respiratory tract infections in elderly hospitalized patients and nursing home residents, with absolute risk reductions of 6.6%–11.7% [7]. Furthermore, a study of 143 residents in a Veterans Affairs nursing home investigated the association between the assignment of an oral hygiene aide and mortality from pneumonia, and found that the odds of dying from pneumonia in the group that did not receive oral care was >3 times that of the group receiving oral care (odds ratio, 3.57; P = .03) [8, 9]. However, the current study challenges this notion. The article by Juthani-Mehta et al in this issue of Clinical Infectious Diseases represents a robust execution of an interventional study in a setting where conducting research is challenging and difficult, yet rewarding and much needed [10]. In this well-designed cluster-randomized study involving 36 nursing homes in Connecticut, Juthani-Mehta et al recruited older nursing home residents with at least 1 of the 2 modifiable risk factors, impaired oral hygiene or swallowing difficulty, as assessed by clinical data as well as oral examinations. The focus of this study was nursing home residents with at least 1 month of stay in the facility. The intervention comprised of manual tooth/ gum brushing along with a chlorhexidine rinse twice a day along with upright positioning. Most exclusion criteria were appropriate, although exclusion of residents with percutaneous endoscopic gastrostomy or nasogastric tubes is debatable. Residents with these devices are known to have higher oropharyngeal colonization with pathogens and may have benefited from this intervention [11]. Study participants were then followed for a maximum of 2.5 years, with a mean duration of follow-up of 1.13 years. Primary and secondary outcomes included time to first chest radiograph–confirmed pneumonia and development of first lower respiratory Received 17 October 2014; accepted 23 October 2014; electronically published 16 December 2014. Correspondence: Lona Mody, MD, MSc, University of Michigan Medical School, Division of Geriatric and Palliative Care Medicine, 300 N Ingalls Road, Rm 905, Ann Arbor, MI 48109 ([email protected]). Clinical Infectious Diseases 2015;60(6):858–9 Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2014. Thiswork iswritten by (a) US Government employee(s) and is in the public domain in the US. DOI: 10.1093/cid/ciu941