Cvcu Case Study

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This study focused on patients cared for in the adult CVICU who were supported by mechanical ventilation. Moreover, the target population was patients who had undergone cardiothoracic surgery, were supported by mechanical ventilation on postoperative days 1–5, and had no pre-existing cognitive dysfunction. Accordingly, this population was studied because patients who are supported by mechanical ventilation represent the largest population of patients at risk for the development of delirium (Jarman et al., 2013). In this situation, the target population included patients who were 18 years of age or older, as this is the age requirement criteria for admission to the adult CVICU. Equally important, patients must not have had a documented…show more content…
Since the manifestations of delirium have been estimated to occur in nearly 80 – 90% of all mechanically ventilated patients who receive care in the ICU (Leite et al., 2014), three factors determined the appropriate sample size for the population studied: 1. The estimated prevalence of the variable of interest – delirium. 2. The acceptable margin of error. 3. The desired level of confidence. Gravetter and Wallnau (2015) contend that a close relationship exists between hypothesis testing and the use of confidence intervals. For example, all estimates in the range are credible values for the assessing of parameters when a confidence interval of 95% is constructed (Gordon, 2010; Gravetter & Wallnau, 2015; Howell, 2014). In comparison, values outside the interval are rejected and are considered improbable. Howell (2014) contends that if the null hypothesis includes the confidence interval within it, the null hypothesis will not be rejected; however, the null hypothesis will be rejected if the value of the parameter is outside the confidence interval. Bonett and Wright (2014) argue that when planning a multiple regression analysis, it is essential to attain a population size that will support the study and provide narrow confidence intervals. Therefore, the confidence level in this study was constructed at 1-alpha or 95% interval, meaning that the null hypothesis could be rejected at the 0.05
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