Table 1. Electronic databases and applied search strategy.

Database	Search strategy (April, 2020)
PubMed     https://www.ncbi.nlm.nih.gov/pubmed	((“Pneumonia, Ventilator-Associated” OR “Pneumonia, Ventilator-Associated” OR “Ventilator Pneumonia Associated” OR “Ventilator-Associated Pneumonia”) AND (“Chlorhexidine” OR “Chlorhexidine Gluconate”))
Scopus     http://www.scopus.com/	((“Pneumonia, Ventilator Associated” OR “Pneumonia, Ventilator Associated” OR “Ventilator Pneumonia Associated” OR “Ventilator-Associated Pneumonia”) AND (“Chlorhexidine” OR “Chlorhexidine Gluconate”))
Embase     http://www.embase.com/	(“Pneumonia, Ventilator Associated” OR “Pneumonia, Ventilator Associated”/Exp OR “Pneumonia, Ventilator-Associated” OR “Ventilator Pneumonia Associated” OR “Ventilator-Associated Pneumonia”/Exp OR “Ventilator-Associated Pneumonia”) AND (“Chlorhexidine”/Exp OR “Chlorhexidine” OR “Chlorhexidine Gluconate”/Exp OR “Chlorhexidine Gluconate”)
SciELO     www.scielo.org	“Pneumonia Ventilator Associated” AND “Chlorhexidine”
Web of Science     http://apps.webofknowledge.com/	((“Pneumonia, Ventilator Associated” OR “Pneumonia, Ventilator Associated” OR “Ventilator Pneumonia Associated” OR “Ventilator-Associated Pneumonia”) AND (“Chlorhexidine” OR “Chlorhexidine Gluconate”))
LILACS     lilacs.bvsalud.org	tw:(tw:(“Pneumonia Ventilator Associated” AND “Chlorhexidine”) AND (db:(“LILACS”)))
Cochrane     https://www.cochranelibrary.com/	((“Pneumonia, Ventilator Associated” OR “Pneumonia, Ventilator Associated” OR “Ventilator Pneumonia Associated” OR “Ventilator-Associated Pneumonia”) AND (“Chlorhexidine” OR “Chlorhexidine Gluconate”))
LIVIVO     https://www.livivo.de/app	((“Pneumonia, Ventilator Associated” OR “Pneumonia, Ventilator Associated” OR “Ventilator Pneumonia Associated” OR “Ventilator-Associated Pneumonia”) AND (“Chlorhexidine” OR “Chlorhexidine Gluconate”))
OpenThesis     http://www.openthesis.org/	((“Pneumonia, Ventilator Associated” OR “Pneumonia, Ventilator Associated” OR “Ventilator Pneumonia Associated” OR “Ventilator-Associated Pneumonia”) AND (“Chlorhexidine” OR “Chlorhexidine Gluconate”))
Open Access Thesis and Dissertations     https://oatd.org/	((“Pneumonia, Ventilator Associated” OR “Pneumonia, Ventilator Associated” OR “Ventilator Pneumonia Associated” OR “Ventilator-Associated Pneumonia”) AND (“Chlorhexidine” OR “Chlorhexidine Gluconate”))