Association of Number of Oral bacteria with Ventilator-Associated Pneumonia and Delirium in Patients in the Intensive Care Unit

  • Arimizu, Chika RDh
  • Akahoshi, Tomohiko MD, PhD
  • Jinno, Teppei DDS, PhD
  • Furuta, Michiko DDS, PhD
  • Ohashi, Ayako MD, PhD
  • Takamori, Shinnosuke MD
  • Wada, Naohisa DDS, PhD

  • 1Department of General Dentistry, Division of Interdisciplinary Dentistry, Faculty of Dental Science, 12923Kyushu University, Fukuoka, Japan

    2Department of Medical Technology, 145181Kyushu University Hospital, Fukuoka, Japan

    3Department Advanced Emergency and Disaster Medicine, Graduate School of Medicine, 12923Kyushu University, Fukuoka, Japan

    4Emergency and Critical Care Center, 145181Kyushu University Hospital, Fukuoka, Japan

    5Division of General Dentistry, 145181Kyushu University Hospital, Fukuoka, Japan

    6Section of Preventive and Public Health Dentistry, Division of Oral Health, Growth and Development, Faculty of Dental Science, 12923Kyushu University, Fukuoka, Japan

    7Department of Neuropsychiatry, Graduate School of Medical Sciences, 12923Kyushu University, Fukuoka, Japan

Tomohiko Akahoshi, Department Advanced Emergency and Disaster Medicine Graduate School of Medicine, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. Email: [email protected]

Journal of Intensive Care Medicine 40(7):p 779-788, July 2025. | DOI: 10.1177/08850666251320924

Objectives

Ventilator-associated pneumonia (VAP) and delirium are major complications among patients in the intensive care unit (ICU). The impact of oral bacterial count on these conditions is not well understood. This study aimed to explore the association between oral bacterial load and the incidence of VAP and delirium in ICU patients.

Methods

In this single-center longitudinal study, 130 patients admitted to the ICU from September 2022 to May 2023 were included. Oral bacteria counts on the tongue were quantified, and assessments of oral health using the Oral Health Assessment Tool (OHAT) and oral moisture levels were also conducted. We examined the associations between oral bacterial count, OHAT scores, and oral moisture with the incidence of VAP and delirium.

Results

The incidence rates of VAP and delirium were 31.4% and 35.4%, respectively. Patients with a high oral bacterial load (≥5.0 × 107 CFU/mL) at ICU admission had a higher likelihood of developing VAP (odds ratio [OR] 7.43, 95% confidence interval [CI] 1.68-32.87) and delirium (OR 3.30, 95% CI 1.04-10.44) compared with those with lower bacterial counts (<1.0 × 107 CFU/mL). No significant associations were found between OHAT scores and oral moisture and the occurrence of VAP or delirium.

Conclusion

A higher oral bacterial count at ICU admission was associated with increased incidences of VAP and delirium.

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