Identify the topic you wish to pursue in your reading program and develop a protocol for your review, using the protocol format in Module 1.
My topic: Efficacy of head of bed elevation in prevention of ventilator associated pneumonia
My question: What is the efficacy of head of bed elevation in decreasing the prevalence of ventilator associated pneumonia in patients in the adult Intensive Care Unit?
Critically ill patients who have been mechanically ventilated for periods longer than 48 hours have the risk of developing Ventilator-Associated Pneumonia (VAP). It is a hospital acquired infection that develops in patients during the process of treatment within the hospital setting and is not present at the time of admission (Chlebicki & Safdar 2007). The pathogenesis of VAP involves the entry of bacteria into the lower respiratory tracts and overwhelms the patients’ defenses. According to Berry et al. (2007) the chances of mechanically ventilated patients developing VAP are between 9% and 27% with a high mortality rate where 33-50% of patients acquiring VAP dying.
Approximately one-third patients in ICUs receive mechanical ventilation as support therapy. When a patient’s chest radiograph shows a progressive or new infiltrate, cavitations, consolidations, or pleural effusions along with one or all of the following symptoms: change in color or new onset of purulent sputum, increase or reduction in white blood cells, organisms cultured from blood, bronchial brushing, etiological agent isolation by transtracheal aspirate or increase in temperature, VAP can be identified in the patient (Synders, Khondowe & Bell 2011).
The risk factors identified with VAP are: staff’s inadequate hand washing, ventilator circuit management practices, antibiotic therapy previously, patients’ supine positioning without backrest elevation, nasogastric alkalinization or the presence of a nasogastric tube (Parsons et al. 2013). According to the Institute of Healthcare improvement’s ventilator bundle, a 30º or more elevation of patient’s bed head, prophylaxis for deep vein thrombosis and peptic ulcer, sedation vacation, and assessing readiness to extubate may reduce risk of complications with mechanical ventilation (Munro et al. 2009).
Oropharyngeal colonization, aspiration, gastric colonization and compromised lung defences are the factors associated with VAP development. The pooling of micro-aspiration of bacteria-laden secretion above the endotracheal cuff of patients intubated leads to respiratory tract colonization. Chlor-hexidine, a cationic chlorophenyl bis-biguanide antiseptic agent has the ability to bind to oral tissues and subsequently release antiseptic properties slowly enabling long period of anti-bacterial action and hence has been used in mechanically ventilated patients as an oral disinfectant (Synders, Khondowe & Bell 2011).
Question – What is the efficacy of a chlorhexidine solution mouthwash in reducing the prevalence of ventilator associated pneumonia in patients in the Intensive Care Unit?
Randomized controlled trials or studies using comparative groups, published in English to investigate oral chlorhexidine as a decontaminant in VAP prevention in critically ill, mechanically ventilated adult patients were included.
Studies that analyzed the use of oral chlorhexidine versus tooth brushing, placebo or oral care interventions comparators to reduce in VAP in critically ill, mechanically ventilated patients were focused.
Study participants had to be mechanically ventilated, aged 18 years or older, critically ill and admitted to the ICU. Tertiary levels of healthcare and different adult ICU will be used in this study which could help to minimise the bias.
To the measure the reduction in prevalence of VAP in mechanically ventilated, critically ill ICU patients was the primary outcome interest.
Studies that were excluded included studies not investigating VAP even if chlorhexidine was used, study of patients below 18 years, patients with known allergy or hypersensitivity to chlorhexidine, edentulous patients, extubated patients and patients already clinically diagnosed with pneumonia at the start of study. Incomplete study or data within studies included, unavailability of full-text articles and high attrition rates are the exclusion criteria for this review. The study will exclude ventilated patient in the emergency department as well as pediatric ICU.
An extensive search was undertaken for literature of published clinical trials that report prevention of Ventilator-Associated Pneumonia with the use of chlorhexidine in oral care. Electronic databases searched to identify sources for relevant studies included MEDLINE, Joanna Briggs Institute, CINAHL, Cochrane, Scopus and Google Scholars and. The reference list of articles and summaries were examined. MeSH terms used for literature search such as Ventilator-Associated Pneumonia, hospital acquired pneumonia, chlorhexidine, mechanically ventilated patients, oral care, oral hygiene, oral decontamination, respiratory tract infection, prevention pneumonia and mouthwash were used for the search.
The titles of the articles obtained by employing the search terms mentioned were considered and those that were relevant to the study on hand were identified. The articles were retrieved and reviewed considering the criteria mentioned for inclusion. The relevant articles were reviewed and analyzed independently to determine the quality of methodology. The methodological quality was assessed using quality assessment form freely available in Cochrane website. The external and internal validities of the RCTs were addressed by the assessment.
To collect information from relevant studies, a data extraction tool is employed in order to accumulate reliability of the data from individual studies. By doing this, the risk of errors during transcription or missing the most relevant information will be minimised. A pilot study will be conducted to determine the feasibility of the study, search range, assessment and extraction tools. The tool will be used is JBI Data Extraction Form for Experimental/Observational Studies (Appendix 1). The tool will be included baseline characteristics such as study method, setting, population, sample size, details of intervention, outcome description, studies results, authors’ conclusion and comments.
Treatment effect measures
The treatment effect measurement choice was using the random effects model (Mantel – Haenszel method), risk ratio with 95% confidence intervals for weighted mean difference and intervals for dichotomous data. The value set for p was 0.05.
All studies included randomized the participants to a treatment or control group. Wherever pertinent data were missing from the trials included, it was regarded as absence of results that add weight to the study.
A statistical analysis software package, Review Manager (RevMan) will be used for analysis where all the data will be entered. By reviewing question, all information extracted from the study (for example: population, sample size, intervention and clinical outcome) will be structured in a manner. The Cochrane Collaboration website offers the software for free. The included studies differed from each other with regard to age, trial settings and methods of treatment. In addition, the study outcome will be organized in the tables to highlight similarities and differences results. The use of the random effects model allows the distribution of effects, and provides a combined estimate and average of value distribution. The effects of interventions will be demonstrated by using meta-analysis to join individual studies results.
After identifying clinical diversity, subgroup analysis will be conducted with respect to the varying concentrations of chlorhexidine used. Data will be entered into review manager to obtain sensitivity analysis.
Validity, Reliability and Quality
These assessments of study data was confirmed by piloting and employing a standardized data extraction form from the Cochrane Collaboration.