To the Editor:
The recent article by La Combe et al. is timely, directly challenging the practice of using oral chlorhexidine in intubated patients to reduce oral bacterial counts and ventilator-associated pneumonia.1 While documenting a lack of efficacy of chlorhexidine to reduce bacterial load in the oropharynx, they failed to address the specific known pulmonary toxicity of chlorhexidine or evaluate the direct toxic impact of chlorhexidine “silent aspiration” into the lung, leaking between endotracheal tube cuff and tracheal mucosa. This would have been of great interest, as specific toxicology concerns remain discounted and with their administration of the 15-ml volumes and 0.12% concentrations applied. The authors did indicate some studies that specifically linked oral chlorhexidine use to increased mortality.
I previously published concerns regarding the silent aspiration of chlorhexidine and toothpaste used in clinical ventilator-associated pneumonia bundles, when my wife nearly succumbed to “silent aspiration” pneumonia in 2015. Ventilator-associated pneumonia and aspiration pneumonia occurred only after a motor vehicle trauma with immediate intubation after 24 to 48 h of normal pulmonary and radiological findings.2 Progressive and severe aspiration pneumonia then developed postoperatively and in conjunction with the prevailing ventilator-associated pneumonia bundle (chlorhexidine and toothpaste), until tracheostomy performed on the ninth day of intubation led to improvement, as secretions now exited onto the anterior neck above the cuff, instead of draining into the lungs.
I was astonished to find during my review of the literature that in animal studies, chlorhexidine greater than 0.1% concentrations exhibit significant pulmonary toxicity.3,4 However, toxicity has not been specifically addressed in intubated humans, where “silent” pulmonary aspiration is a recognized and expected risk. Toothpaste (inorganic silicates) is also a particulate material used in ventilator-associated pneumonia with known pulmonary implications and should be similarly concerning, as well as the scandal involving chlorhexidine and the National Quality Forum’s (Washington, DC) guidelines for sterile skin prep: The U.S. Justice Department settled a $40 million whistleblower lawsuit in early 2014, alleging that CareFusion (USA), the maker of ChloraPrep, had inappropriately influenced the National Quality Forum.5 Thus, business interests and guidelines do not ensure patient safety. Both toothpaste and chlorhexidine have found support as ventilator-associated pneumonia bundle quality parameters to a large degree, because of dental hygiene use in nonintubated daily living care—without concerns specific to pulmonary dangers from laryngeal incompetence and silent aspiration, a problem known to be inherent in intubated patients.
Minimization of ventilator-associated pneumonia in 2019 may require specific investigations regarding “silent aspiration” as causative and the importance of (1) elimination of all pulmonary toxins introduced into the oral cavity, (2) maximally effective oral hygiene using pulmonary tolerated aqueous and antibiotic solutions via electrical power brushing,6 and (3) early tracheostomy to allow egress of secretions from above the cuff and return of glottic protective closure mechanisms, where indicated.
The author declares no competing interests.