Ventilator Associated Pneumonia and Toothbrushing

Objective, Hypothesis, and Legal-ethical issues

The objective of this randomized controlled trial, “to compare the incidence of VAP in critical care patients receiving oral care with and without manual brushing of teeth”, is clearly stated in the abstract, as well as the introduction (Lorente, et al., 2012). There was one hypothesis that was identified for this study: “adding toothbrush use to oral care with 0.12% chlorhexidine could reduce the incidence of VAP, by reducing the presence of endogenous oropharyngeal flora.” The independent variable in this study is manually brushing teeth with a toothbrush. The dependent variables are the incidence of ventilator associated pneumonia (VAP), and the amount of oropharyngeal flora present. The protocol for this study was reviewed and approved by the Institutional Review Board (Lorente, et al., 2012). Informed consent was obtained from either the participant themselves or from their legal guardians.

Sample

The convenience sample consisted of 436 individuals who were patients in a 24-bed medical-surgical ICU at the Hospital Universitario de Canarias in Spain between August 2010 and August 2011 (Lorente, et al., 2012). A power analysis is a “mathematical procedure to determine the number for each group of the study” (LoBiondo-Wood & Haber, 2014). The sample size was not appropriate for the study, as it only represents a power of 12% (Lorente, et al., 2012). According to the power analysis, to achieve a power of 80%, a total of 13,576 participants were needed.

Inclusion criteria was obviously stated, noting that each individual must be admitted to the ICU and have been on a ventilator for 24 hours or more (Lorente, et al., 2012). There were no significant differences among the control and intervention group in regard to baseline characteristics such as: age, sex, diagnosis group, use of antibiotics, paralytic agents, reintubation, tracheostomy, enteral nutrition, or duration of mechanical ventilation. Exclusion criteria was clearly defined as the following: edentulous, age less than 18 years, human immunodeficiency virus, white blood cell count less than 1,000, and mechanical ventilation duration for less than 24 hours. The sample was not randomly selected; however, there was random assignment to either the intervention or control group using Microsoft Excel.

Lack of random selection of the participants, inappropriate sample size, and exclusion criteria impact generalizability. Although the study focuses on a particular population, it could potentially be tested in other ICUs or skilled facilities that accept patients on a ventilator; however, if a patient is not ventilated, they do not qualify for the study. Some of the exclusion factors also limit generalizability. For example, a patient may have been ventilated for over 24 hours, but due to a diagnosis of HIV, they were not considered.

Research Design, Methods, and Data Analysis

A randomized controlled trial was used, providing Level II evidence (LoBiondo-Wood & Haber, 2014). Definitions regarding diagnosis of pneumonia and what ventilator associated pneumonia is, were clearly stated (Lorente, et al., 2012). Data was collected upon admission and intubation and continued to be collected throughout the patient’s duration in the ICU. This was done by obtaining aspirate samples and throat swabs. These samples were analyzed by an expert panel, who ultimately determined whether the patient had developed ventilator associated pneumonia. Although unstated, it appears as though the data collection was consistent for each participant; however, without notation of training or supervision, one might question the reliability of the data collection process.

To analyze the quantitative variables, a t-test was performed and compared to a calculated standard deviation (Lorente, et al., 2012). A p-value of less than 0.05 was considered statistically significant. Among the intervention and control group, p = 0.75, indicating no statistically significant differences in the incidence of ventilator associated pneumonia when using or not using a toothbrush during oral care.

There are no threats to internal validity existing from history, mortality, or maturation. The instruments used to collect data lack psychometric properties, potentially affecting how sufficiently the variables are measured. Threats to external validity stem from the sample. Because it is a convenience sample and there is an inadequate number of participants, potential for bias arises. This can hinder the generalizability of the outcome.

Conclusions, Recommendations, and Limitations

The hypothesis for this study, “adding toothbrush use to oral care with 0.12% chlorhexidine could reduce the incidence of VAP, by reducing the presence of endogenous oropharyngeal flora,” was not supported (Lorente, et al., 2012). Among the 436 ICU patients who were mechanically ventilated, there was no statistically significant differences in the incidence of VAP between the control and intervention group. Because of this, there is not quality evidence to suggest implementation of manual brushing of the teeth after oral care in a clinical setting. The study was not feasible, due to inappropriate sample size; however, it may be beneficial to conduct further research to determine a more accurate relationship between manually brushing teeth and ventilator associated pneumonia.

Limitations to the study include sample size, assessment and compliance, and potential bias (Lorente, et al., 2012). The study was not feasible due to a sample size with a power of 12%, which was not representative of the population. Another limitation noted is that performance of periodontal state was not assessed, nor was compliance checked for oral care. It is unknown whether oral care was being performed appropriately or at all, which ultimately affected the validity of the data. In addition, because oral care is a physical action that can be observed, the study could not be blinded. This increases the opportunity for unintentional bias toward one group.

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