The Effectiveness and Impact of Preoperative Dental Hygiene Care on the Incidence of Postoperative Pneumonia after Esophagectomy: An Interventional Prospective Study

Abstract

Background: Postoperative pneumonia is a major cause of postoperative mortality after esophagectomy. Preoperative oral hygiene care is reportedly effective to prevent pulmonary complications after esophagectomy. Methods: Since April 2012, we have included preoperative oral hygiene in the standard perioperative care regimen for esophagectomy and have accumulated data on 188 consecutive patients undergoing esophagectomy to evaluate oral hygiene care’s effectiveness. To determine basic (i.e. non-clinical) and clinical effects of preoperative oral care, we prospectively observed the incidence rate of postoperative pneumonia and accumulated perioperative culture study and oral bacteria count data on these 188 patients. One hundred five patients studied in our previous retrospective study from 2009 to 2012 were enrolled as a historical control.Results: In the current study’s patients, no significant reduction of postoperative pneumonia was observed compared to the historical control (30 out of 188 vs. 21 out of 105, P=0.423). Perioperative culture studies showed significantly decreased positivity in preoperative oral samples (11% in dental plaque and 13% in tongue coating) but no such decrease was observed in studies of postoperative gastric juice and endotracheal sputum. With the exception of postoperative endotracheal sputum, perioperative cultures had few of the pathogenic microbes identified in pneumonia patients. In the analyses of oral bacterial count, oral microbial flora were significantly decreased after oral care in both dental plaque (median ratio to before care: 1:0.13, P<0.0001) and tongue coating (median ratio: 1:0.015, P<0.0001); however, only in the dental plaque did the decrease last until the day of the operation (median ratio: 1:0.10, P=0.0008). Logistic regression analysis showed only the bacterial amount in dental plaque on the operation day (P=0.026) to be marginally correlated to the incidence of pneumonia. Conclusions: Although perioperative oral hygiene care had a significant impact on oral bacterial load, its contribution to the prevention of postoperative pneumonia was limited.Trial registration: This study was registered and approved by the institutional review board of The University of Tokyo Hospital: Approval number: 3383, Date: 26th November, 2011