# Does oral hygiene prevents nosocomial infections in hospitalized patients? A systematic review and meta-analysis

## TL;DR

This study finds that using chlorhexidine for oral hygiene can reduce hospital-acquired infections in patients, especially when used three or more times daily.

## Contribution

The study provides new evidence that chlorhexidine-based oral hygiene reduces nosocomial infections when used at higher frequencies.

## Key findings

- Oral hygiene with chlorhexidine reduces the risk of nosocomial infections and ventilator-associated pneumonia.
- Using chlorhexidine three or more times daily significantly lowers infection risk.
- Chlorhexidine use does not affect hospital or ICU stay duration.

## Abstract

This study aimed to evaluate the impact of oral hygiene (OH) with chlorhexidine (CHX) on the evolution of nosocomial infections (NI).

Electronic searches were carried out in PubMed, Scopus, Cochrane Library, Web of Science, VHL, and Grey Literature databases. Randomized clinical trials were included. Methodological quality and risk of bias were assessed using RoB 2.0. Meta-analyses were carried out comparing patients who did or did not receive OH with CHX (0.05%, 0.12% and 2%) for NI, Ventilator-Associated Pneumonia (VAP), S. aureus infection (SA), duration of mechanical ventilation (MV), length of hospital stay and Intensive Care Unit (ICU). The certainty of evidence (CE) was evaluated with GRADE approach.

Thirteen studies were selected for quantitative and qualitative synthesis. The risk for VAP (RR 0.72 [0.58, 0.90], p=0.003) and NI (RR 0.70 [0.58, 0.83], p<0.001) were lower in patients of the CHX groups compared to controls, independently for [CHX] used for NI (RR≥0.49, p≤0.03). Patients who received CHX 2×/day presented similar risk to control (RR 0.98 [0.75, 1.30], p=0.91); while 3 and 4×/day or more (RR≥0.52, p≤0.002) presented lower risk for NI. Similar risk for SA was observed among groups (RR 0.42 [0.14, 1.26], p=0.12). The average days of hospitalization (p=0.67), ICU stay (p=0.37) and MV (p=0.57) did not differ between the groups. CE ranged from very low to moderate.

OH with CHX reduced NI, regardless of concentration, when used 3×/day or more. However, it had no effect against AS and did not reduce length of hospital stay.

Key words:Nosocomial infections, dental plaque, intensive care patients, oral decontamination, chlorhexidine.