Generating Evidence for Evidence-based Practice in healthcare

Generating Evidence for Evidence-based Practice in healthcare

The development of pneumonia caused by mechanical ventilation is a significant problem in the intensive care units of hospital facilities. Ventilator-associated pneumonia (VAP) is the “most commonly reported healthcare-acquired infection” in patients requiring mechanical ventilation support (Garcia et al., 2009, p. 524). One of the most common reasons for an ICU admission is related to respiratory distress or failure. VAP is described as a form of nosocomial infection which occurs after the first 48 hours of receiving mechanical ventilation (Augustyn, 2007). The length of stay (LOS) for patients developing VAP is higher than those never requiring mechanical ventilation by an increase of approximately six days (Garcia et al. 2009). In intensive care units (ICUs) across the United States (US), ventilator-acquired pneumonia also results in prolonged periods of actual mechanical ventilation, the excess use of antimicrobial products, increased utilization of healthcare resources and costs, and significant increase in morbidity and mortality (Coffin et al., 2008). Garcia et al. (2009) found on average, estimated costs of an additional $11, 897 to $150,841 per individual case were spent. VAP has a significant economic impact on our society, costing hospitals money which potentially could have been saved. Generating Evidence for Evidence-based Practice in healthcare

Numerous risks factors contribute to the development of ventilator-acquired pneumonia as mechanical ventilation presents a unique set of challenges for the patient requiring intubation and ventilator support. Rigorous clinical studies show oral secretions pose an increased risk for developing VAP (Augustyn, 2007). Treatments, strategies and evidence-based interventions have been developed to decrease the risks and reduce the prevalence of VAP. There is evidence indicating the use of oral chlorhexidine and the removal of oral secretions before position changes may diminish the risks of developing ventilator-acquired pneumonia. By reducing the levels of bacteria in the oropharynx there would theoretically be a decrease in the prevalence of nosocomial pneumonia (Houston et al., 2002). Research demonstrates the use of 0.12% chlorhexidine gluconate oral rinse (CHX) pre and postoperatively reduces the incidence of VAP in patients who are intubated greater than 24 hours. Generating Evidence for Evidence-based Practice in healthcare

Foreground Question

In adults supported with mechanical ventilation, what is the effect of oral chlorhexidine use and removal of oral secretions prior to position changing on the development of ventilator-acquired pneumonia?

Review of Evidence and Synthesis of Literature

This is a literature analysis of research reports and literature reviews which studied the effects of removal of oral secretions prior to position change on the occurrence of VAP. A summary of the articles can be found in Appendix C. The studies varied in design; from randomized to non-randomized, placebo, to longitudinal and a pilot study. Strength for each study is noted at Level II on the hierarchy as each one is a randomized or nonrandomized clinical study. The research supports our clinical question and was utilized with the development of additions to be incorporated into the already existing ICU VAP protocol. Generating Evidence for Evidence-based Practice in healthcare

The studies focused on in this review consisted of evidence evaluating oral secretion removal and the use of chlorhexidine gluconate oral rinse to prevent VAP. The cost effectiveness of these interventions was found to be significant. Studies showed oral secretions as being the medium to carry pathogens within the oropharyngeal site down into the respiratory track. The literature hypothesized removing oral secretions prior to the position change of a patient can prevent or minimize the movement of organisms into the respiratory tract which lead to VAP development. Some researchers also concluded the significance of chlorhexidine use for reducing nosocomial infections. The combination of both interventions creates a profound effect on reducing VAP occurrences its research importance, which this practice change aims to strongly support. Generating Evidence for Evidence-based Practice in healthcare

The review of literature consists of evidence dating from 1996 to 2008, indicating the need for continued research and close monitoring of clinical practice changes based on the best evidence at the moment. This problem was identified long ago and yet still needs further evidence for best practice. Three articles discuss removing oral secretions prior to position changes of patients which are one of the two independent variables of interest for this review. In one of those studies, VAP was diagnosed in 24 of 159 patients in the control group, but only in five of 102 patients in the study group within the study group receiving oral suctioning prior to all position changes (Chao, Chen, Wang, Lee, & Tsai, 2008). A similar study showed VAP occurrence at 2.6% in the study group and 11% in the control group with probability of < 0.001 (Tsai, Lin, Chang, 2008). Generating Evidence for Evidence-based Practice in healthcare

Studies by DeRiso et al. (1996) and Houston et al. (2002) each sought to evaluate the efficacy of oropharyngeal decontamination on nosocomial infections in patients undergoing heart surgery using CHX before and after surgery. Both DeRiso et al. and Houston et al. discovered an overall reduced rate of VAP (52% and 69% respectively for each study). The significance level for both studies was less than .01 (use the higher of the two) with the use of CHX with oral suctioning of subjects for these studies.

Another related intervention assessed in a similar randomized clinical study was the use of subglottal suctioning by Smulders et al. (2002) and its effect on VAP incidence. This intervention was appropriate for this review of literature; four percent of patients who underwent continuous suctioning developed VAP as compared to 16% in the control group. A common finding in the studies reviewed was the savings in spite of the costs of using CHX and equipment for oral and subglottal secretion removal. The majority of these studies revealed a significantly reduced duration of mechanical ventilation and LOS in the ICU. Generating Evidence for Evidence-based Practice in healthcare


All research studies in this literature review, with the exception of Tsai et al.’s study, consisted of study groups homogenous in patient samples, which suggest effective randomization. Tsai et al.’s study has patient heterogeneity (of both medical and surgical ICU patients) which may have confounded the results. Also, the results of Chao et al.’s study did yield a significant difference with the distribution of patients having a history of COPD, DM, use of antacids, and surgery. These variables were then evaluated with logistic regression for their relationship in VAP development, and the results of the logistic regression showed no significant impact on the direct development. Overall the reviews are well organized, use appropriate language, and use mostly all paraphrasing. This review summarizes key finding of evidence for clinical practice, and provides similar conclusions like our study regarding interventions to implement in practice.

This literature review consisted of all but one study which were experimental in nature and hold “a high degree of internal validity because of the use of manipulation and randomization” (Polit & Beck, 2008, p. 295). Tsai et al.’s study was a time-sequenced, non-randomized quasi-experimental study most vulnerable to threats to internal validity out of all the literature reviewed. But the remaining study participants in the rest of these experimental designs were all randomized after meeting inclusion criteria. Only two studies (by Houston et al. and Tsai et al.) may have had questionable internal validity. Houston et al.’s study group was large but possibly too broad with subjects intubated for too short of a period to have the intervention be significant. This provides evidence for the need to implement such an intervention and continue research. This may have led to potential Type I and II errors. Tsai et al.’s weakness was the limitation of a non-randomized control study and patient heterogeneity as previously mentioned. In addition, Chao et al. used a staff nurse of the ICU to conduct data collection; because it is her ICU she may want “her unit” to do well with compliance with the study, creating bias. Also, in both this and Smulders et al.’s studies suctioning pressure was discussed. Internal consistency was not documented and this lack of information affects the reliability of the measurement tools. Selection bias does not appear to be a concern in these studies, and there appears to be no threat of history and the groups were mainly homogenous. Overall the internal validity of the research in this literature review is rather strong taking into consideration these few discussed weaknesses. Generating Evidence for Evidence-based Practice in healthcare

Regarding external validity, the research findings in these studies can easily be generalized to similar mechanically-ventilated ICU adult populations. The patient populations were representative of the typical ICU population and because of this, external validity is strong. Steps were taken to control characteristics which could impact the groups being compared, and any requirements for participants were taken into consideration when developing the sample.

The study by DeRiso et al. was double-blinded and placebo-controlled in design techniques, and Smulders et al.’s study reported blinding with the radiologists in regards to reading all X-ray reports. These techniques enhanced the internal validity. The studies were each performed in only one setting, but could very easily be replicated in another ICU environment. Tsai et al. and Chao et al.’s studies had a period during their research which was dedicated to educating staff on the protocol to be implemented to the experimental group. This enhanced intervention fidelity in both studies. Also, the individual collecting the data from Chao et al.’s study group was a trained staff member of the ICU floor, and such actions facilitated a strong reaction with the intervention and validated construct. No incentives were provided to staff members for compliance with Chao et al.’s study, but staff was aware of the fact that the clinical setting was being monitored and data collected based upon their performance. However, normally nurses are not monitored closely and corrected for actions. Education for new changes to protocols is usually brief, and like any change, will take some time for the staff to acclimate to. Generating Evidence for Evidence-based Practice in healthcare

There appears to be no apparent threat to construct validity with the discussed literature. However one could argue the researcher’s expectancies for desired outcomes playing an effect. For example, Tsai et al. and Chao et al.’s studies involved the staff received a thorough education and period of time to learn the protocol for the study’s intervention. Knowing the researcher’s expectations, this could “become part of the treatment construct that is being tested” (Polit and Beck, 2008, p. 301). Researchers appropriately balanced all concerns for validity in their study Generating Evidence for Evidence-based Practice in healthcare

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