Oral Chlorhexidine Against Ventilator-Associated Pneumonia and Microbial Colonization in Intensive Care Patients

Impaired oral health: a required companion of bacterial aspiration pneumonia

Laryngotracheal aspiration has a widely-held reputation as a primary cause of lower respiratory infections, such as pneumonia, and is a major concern of care providers of the seriously ill orelderly frail patient. Laryngeal mechanical inefficiency resulting in aspiration into the lower respiratory tract, by itself, is not the cause of pneumonia. It is but one of several factors that must be present simultaneously for pneumonia to develop. Aspiration of oral and gastric contentsoccurs often in healthy people of all ages and without significant pulmonary consequences. Inthe seriously ill or elderly frail patient, higher concentrations of pathogens in the contents of theaspirate are the primary catalyst for pulmonary infection development if in an immunocompromised lower respiratory system. The oral cavity is a complex and ever changing eco-environment striving to maintain homogeneity among the numerous microbial communities inhabiting its surfaces. Poor maintenance of these surfaces to prevent infection can result inpathogenic changes to these microbial communities and, with subsequent proliferation, can altermicrobial communities in the tracheal and bronchial passages. Higher bacterial pathogen concentrations mixing with oral secretions, or with foods, when aspirated into an immunecompromised lower respiratory complex, may result in bacterial aspiration pneumonia development, or other respiratory or systemic diseases. A large volume of clinical evidence makes it clear that oral cleaning regimens, when used in caring for ill or frail patients in hospitals and long-term care facilities, drastically reduce the incidence of respiratory infection and death. The purpose of this narrative review is to examine oral health as a required causative companionin bacterial aspiration pneumonia development, and the effectiveness of oral infection control inthe prevention of this disease.

A Review of Chlorhexidine Oral Care in Patients Receiving Mechanical Ventilation

BACKGROUND

Chlorhexidine gluconate has been considered the criterion standard of oral care for patients receiving mechanical ventilation because of its ability to reduce the incidence of ventilator-associated events. Optimal concentrations and frequencies remain unclear, as do adverse events related to mortality in various intensive care unit populations.

OBJECTIVE

To examine the current evidence for the efficacy of chlorhexidine gluconate in reducing the incidence of ventilator-associated events, mortality, intensive care unit length of stay, and duration of mechanical ventilation in patients receiving ventilator support.

METHODS

In this integrative review, CINAHL (Cumulative Index to Nursing and Allied Health Literature), MEDLINE, and Health Source: Nursing/Academic Edition were searched using terms related to mechanical ventilation and chlorhexidine gluconate oral care with dates ranging from 2012 to 2023.

RESULTS

Seventeen articles were included in this review: 8 systematic reviews, 8 randomized clinical trials (3 of which were not included in any systematic review), and 1 quasi-experimental study. Chlorhexidine gluconate oral care was associated with a reduced incidence of ventilator-associated events, but efficacy depended on concentration and frequency of administration. With stratification by intensive care unit population type, a nonsignificant trend toward increased mortality was found among non-cardiac surgical patients who received this care.

CONCLUSION

The evidence regarding the efficacy of chlorhexidine gluconate oral care in reducing ventilator-associated events in specific intensive care unit populations is contradictory. Recently published guidelines recommend de-implementation of chlorhexidine gluconate oral care in all patients receiving mechanical ventilation. Such care may be beneficial only in the cardiac surgical population.

Oral Care and Positioning to Prevent Ventilator-Associated Pneumonia: A Systematic Review

Introduction

Ventilator-associated pneumonia (VAP) is one of the most common nosocomial infections in critical patients. The negative impacts of VAP on patient outcomes emphasize the importance of effective preventive measures such as oral care and patient positioning. The aim of this review was to investigate the impact of oral care and positioning on the prevention of VAP among patients in the intensive care unit.

Methods

This review was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A comprehensive search was performed. The methodological quality of included studies was appraised using Joanna Briggs Institute checklists.

Results

In total 13 studies were included, all of them were randomized controlled trials. Six out of nine studies about oral care have significant results on VAP incidence. Regarding the position, Patients positioned at a 45-degree were less likely to develop VAP than those positioned at a 30-degree and those in a supine position.

Conclusion

Although patients positioned at 45-degree angle were less likely to develop VAP than those at 30-degree, it is necessary to individualize this practice before recommending it, once there are some contraindications, such as neurocritical patients. Regarding oral care to prevent VAP, considering the current guidelines' recommendation not to use oral chlorexidine, further studies evaluating alternatives are needed.

Exploring the complex relationship between the lung microbiome and ventilator-associated pneumonia

INTRODUCTION

Understanding the presence and function of a diverse lung microbiome in acute lung infections, particularly ventilator-associated pneumonia (VAP), is still limited, evidencing significant gaps in our knowledge.

AREAS COVERED

In this comprehensive narrative review, we aim to elucidate the contribution of the respiratory microbiome in the development of VAP by examining the current knowledge on the interactions among microorganisms. By exploring these intricate connections, we endeavor to enhance our understanding of the disease's pathophysiology and pave the way for novel ideas and interventions in studying the respiratory tract microbiome.

EXPERT OPINION

The conventional perception of lungs as sterile is deprecated since it is currently recognized the existence of a diverse microbial community within them. However, despite extensive research on the role of the respiratory microbiome in healthy lungs, respiratory chronic diseases and acute lung infections such as pneumonia are not fully understood. It is crucial to investigate further the relationship between the pathophysiology of VAP and the pulmonary microbiome, elucidating the mechanisms underlying the interactions between the microbiome, host immune response and mechanical ventilation for the development of VAP.

Meta-Analysis of the Efficacy and Safety of Chlorhexidine for Ventilator-Associated Pneumonia Prevention in Mechanically Ventilated Patients

Objective

To explore the efficacy and safety of chlorhexidine oral care in the prevention of ventilator-associated pneumonia (VAP) by means of meta-analysis.

Methods

Randomized controlled trials on the effect of chlorhexidine oral care on the incidence of VAP in patients on mechanical ventilation were searched in PubMed, Scopus, Cochrane Library, and Embase from May 1, 2022. Two researchers independently screened and included the study, extracted the data, and evaluated the literature quality. RevMan5.3 software was used for meta-analysis.

Results

Meta-analysis of 13 included literature studies involving 1533 patients showed that oral care with chlorhexidine solution could reduce the incidence of VAP in patients with mechanical ventilation and the difference was statistically significant (RR = 0.61, 95% CI (0.46, 0.82), P=0.04). However, the results showed that the incidence of VAP of low concentration (0.02%, 0.12%, and 0.2%) and high concentration (2%) of chlorhexidine in the intervention group was lower than that in the control group and the difference was statistically significant (RR = 0.70, 95% CI (0.51, 0.96), P=0.03; RR = 0.41, 95% CI (0.27, 0.62)). There was no significant difference in mortality between the two groups (RR = 1.01, 95% CI (0.85, 1.21), P=0.87). There was no statistical significance in days ventilated or days in ICU between the two groups (RR = -0.02, 95% CI (-0.19, 0.16), P=0.84; RR = 0.01, 95% CI (-0.11, 0.14), P=0.85).

Conclusion

Existing evidence shows that chlorhexidine used for oral care of patients with mechanical ventilation can reduce the incidence of VAP, and high concentration of chlorhexidine (2%) or low concentration of chlorhexidine (0.02%, 0.12%, 0.2%) has a significant effect on the prevention of VAP. Considering the safety of clinical application, it is recommended to use 0.02%, 0.12%, and 0.2% chlorhexidine solution for oral care.

[Update of the recommendations of the Pneumonia Zero project]

La pandemia por el SARS-Cov-2 ha impactado negativamente en la aplicación de las recomendaciones de Neumonía Zero y se ha acompañado de un incremento de las tasas de Neumonía asociada a ventilación mecánica (NAVM) en las unidades de cuidados intensivos de España. Con el objetivo de disminuir las tasas actuales a 7 episodios por 1000 días de VM, se han actualizado las recomendaciones del proyecto inicial.

Se identificaron, 27 medidas que se clasificaron en 12 medidas funcionales (posición semisentada, higiene estricta de manos, entrenamiento para manipular la vía aérea, valoración diaria de posible extubación, protocolización del destete, traqueostomía precoz, ventilación no invasiva, vigilancia microbiológica, cambio de tubuladuras, humidificación, fisioterapia respiratoria, nutrición enteral postpilórica), 7 mecánicas (control de la presión del neumotaponamiento, tubos con aspiración subglótica, nutrición con sondas de bajo calibre/en intestino delgado, aspiración de secreciones con circuitos cerrados/abiertos, filtros respiratorios, cepillado de dientes, técnicas de presión negativa en la aspiración de secreciones) y 8 farmacológicas (descontaminación selectiva digestiva, descontaminación orofaríngea, ciclo corto de antibióticos, higiene de boca con clorhexidina, antibióticos inhalados, rotación de antibióticos, probióticos, anticuerpos monoclonales).

Cada medida se analizó de forma independiente, por al menos dos miembros del grupo de trabajo, mediante una revisión sistemática de la literatura y una revisión iterativa de las recomendaciones de las sociedades científicas y/o grupos de expertos.

Para la clasificación de la calidad de la evidencia y fuerza de las recomendaciones se siguió la propuesta del grupo GRADE. Para determinar el grado de recomendación, cada medida fue puntuada por todos los miembros del grupo de trabajo en relación con su efectividad, tolerabilidad y aplicabilidad en las UCI españolas a corto plazo de tiempo. Se solicitó el apoyo de expertos externos en alguna de las medidas que se revisaron. Se seleccionaron aquellas medidas que alcanzaron la máxima puntuación.

Risk Factors and Nursing Countermeasures of Ventilator-Associated Pneumonia in Children in the Intensive Care Unit

Objective

This study discussed and analyzed the risk factors and nursing countermeasures of ventilator-associated pneumonia (VAP) in the children intensive care unit (ICU).

Methods

In this study, 155 children with mechanical ventilation in the pediatric intensive care unit from Oct. 2018 to Oct. 2020 were chosen as research objects. We retrospectively analyzed the clinical data of children and divided them into VAP groups and non-VAP groups according to the occurrence of VAP. Subsequently, we adopted a univariate and multivariate logistic regression model to analyze and clarify the risk factors of VAP and formulated the corresponding nursing countermeasures.

Results

49 cases of total research objects had occurred VAP, with an infection rate of 31.62%. The primary pathogenic bacteria were Gram-negative bacteria (43/70, 61.43%). According to multivariate logistic regression analysis, the duration of mechanical ventilation, invasive procedures, and application of hormones and antacids are all independent risk factors for VAP in pediatric ICU. The VPA group had longer hospital stay than the non-VAP group, and the difference was statistically significant ((20.92 ± 4.16)d, (15.24 ± 3.77)d, t = 8.4383, P ≤ 0.001). The hospitalization cost of the VPA group was substantially higher than that of the non-VAP Group ((45.8 ± 10.4) thousand Yuan, (33.2 ± 4.3) thousand Yuan, t = 10.6822, P ≤ 0.001).

Conclusion

Children admitted to the pediatric ICU have a high VAP incidence. The primary pathogenic bacteria are Gram-negative bacteria. As the occurrence of VAP is closely related to a variety of factors, we should take targeted nursing countermeasures to reduce the duration of mechanical ventilation and the frequency of invasive operations and use the hormone and antacids rationally to reduce the risk of VAP and improve the prognosis.

The effect of different concentrations of chlorhexidine on microbial colonization: A double-blinded randomized controlled study

AIM

Study aims were to determine the most effective chlorhexidine concentration to be used in reducing microbial colonization in patients under mechanical ventilation and to examine the effect of oral care using different concentrations on the integrity of the oral mucous membranes.

DESIGN

This research was a randomized controlled double-blinded experimental study.

METHOD

The sample of study consisted of the 116 adult patients who remained intubated. Oral care was given to patients 4 times/day as per nurse protocol. Every morning during for 4 days, the intraoral mucosa of all groups of patients was assessed. Microbial colonization samples from oral mucosa were taken in the morning before oral care. A determination of the species of microorganisms in these samples was made.

RESULTS

A statistically significant difference was found with regard to the reproduction of microorganisms between the oral mucosa samples taken from patients using 2% and 1% chlorhexidine solutions (P < 0.001). In the cultures taken from patients on the first and fourth days of intubation, a total of 36 different microorganisms were seen to be reproducing.

CONCLUSION

It was concluded that the most effective oral solution for the prevention of microbial colonization in patients under mechanical ventilation was chlorhexidine 1%.

Effect of 0.12% Chlorhexidine Use for Oral Care on Ventilator-Associated Respiratory Infections: A Randomized Controlled Trial

BACKGROUND

Evidence suggests that the effect of 0.12% chlorhexidine (CHX) use for oral care on the development of ventilator-associated pneumonia (VAP) and ventilator-associated tracheobronchitis (VAT) is lacking. Evidence-based approaches to the prevention of VAP and VAT are of paramount importance for improving patients' outcomes.

OBJECTIVES

This study aimed to (1) compare the effect of 0.12% CHX use for oral care on preventing VAP and VAT with the placebo group, as well as (2) compare its effect on oral health and prevention of oral microbial colonization with the placebo group.

METHODS

Prospective, single-blinded, randomized controlled trial performed in 2 intensive care units at a hospital. The sample comprised 57 mechanically ventilated adults randomly allocated to the 0.12% CHX group and the placebo group. Barnason's oral assessment guide was used to evaluate the oral health of both groups before oral care during the first 24 hr of tracheal intubation (Day 0) and at Day 2 and Day 3. Oropharyngeal secretion, endotracheal tube aspirate, and nonbronchoscopic bronchoalveolar lavage samples were collected on Day 0 and Day 3.

RESULTS

The rate of VAT development was not statistically different between the groups (p = .318). However, a significant difference existed in the rate of VAP development (p = .043). The frequency of oropharyngeal colonization significantly decreased in the 0.12% CHX group compared with the placebo group at Day 3 (p = .001).

CONCLUSION

The use of 0.12% CHX for oral care could be effective for VAP prevention and reducing microbial colonization in mechanically ventilated patients.