The effectiveness of systematic perioperative oral hygiene in reduction of postoperative respiratory tract infections after elective thoracic surgery in adults: a systematic review

BACKGROUND: Nosocomial infections are a significant contributor to patient morbidity and mortality. Nosocomial infections significantly increase hospital length of stay and total hospital costs. Thoracic surgery, mechanical ventilation and/or admission to an intensive care unit are known to increase patients' risk for nosocomial respiratory tract infection.

OBJECTIVES: To identify, appraise and synthesize the best available evidence on the effectiveness of systematic perioperative oral hygiene in the reduction of postoperative respiratory airway infections in adult patients undergoing elective thoracic surgery.

INCLUSION CRITERIA: Patients over the age of 18 years who had been admitted for elective thoracic surgery, regardless of gender, ethnicity, diagnosis severity, co-morbidity or previous treatment.Perioperative systematic oral hygiene (such as mechanical removal of dental biofilm or plaques and/or systematic use of mouth rinse) performed by patients themselves or by healthcare staff (such as nurses).Randomized controlled trials and quasi-experimental studies.Nosocomial infections, specifically respiratory tracts infections, and surgical site infections

SEARCH STRATEGY: Multiple databases (PubMed, CINAHL, Embase, Scopus, Swemed+, Health Technology Assessment Database and Turning Research Into Practice [TRIP] database) were searched from 1980 to December 2014. Studies published in English, German, Danish, Swedish and Norwegian were considered for inclusion in this review.

METHODOLOGICAL QUALITY: Two independent reviewers used the standard critical appraisal tool from the Joanna Briggs Institute to assess the methodological quality of studies.

DATA EXTRACTION: The process of data extraction was undertaken independently by two reviewers using tools from the Joanna Briggs Institute.

DATA SYNTHESIS: Quantitative results were synthesized in meta-analysis.

RESULTS: This review includes six studies: three randomized controlled trials and three quasi-experimental studies.The absolute magnitude of the summary effect sizes were: for nosocomial infections relative risk (RR) 0.65 (95% confidence interval [CI] 0.55-0.78) for respiratory tract infections RR 0.48 (95%CI: 0.36-0.65) and for deep surgical site infections RR 0.48 (95%CI 0.27-0.84).

CONCLUSIONS: Systematic perioperative oral hygiene reduces postoperative nosocomial, lower respiratory tract infections and surgical site infections but not urinary tract infections. The effect is statistically, clinically and practically significant.Perioperative decontamination of the nasopharynx and/or oropharynx is a strategy worth pursuing. The intervention is cheap and can easily be carried out by the patients themselves. (Grade A)Studies testing decontamination of the nasopharynx and/or oropharynx have until now only included patients undergoing thoracic surgical procedures. As the interventions are cheap, easy to carry out and have a great impact on the patients' outcome, it is recommendable to carry out more studies involving other type of patients undergoing major surgery with a high prevalence of nosocomial infections, respiratory tract infections and surgical site infections.