This is critique of a randomized controlled trial study in relation to catheter-related bacteremia as the most frequent complication of the central venous catheter (CVC). The purpose of the study is to decide whether the use of 0.5% tincture of chlorhexidine or 10% povidone-iodine solution, is the most beneficial for preventing CVC exit site colonization, significant catheter tip colonization and catheter-related bacteremia in ICU patients. Protection of Human Participants
Risks and Benefits
Human subjects are necessary in research and must be treated with respect. The authors of this study did not address the actual risks and or benefits of being involved as a participant of this study. However, two citations in the introduction, referencing chlorhexidine as better than povidone-iodine for preventing infections and catheter related sepsis infers the povidone-iodine group will not be receiving equal treatment. It was not stated that the participants were aware of the aforementioned findings. Since the participants were randomly selected into groups, there is a 50% chance of the participant receiving the least effective cutaneous antisepsis for their central venous catheter (CVC) insertion and care. Consents and Approvals
Informed consent was received from each participant, or their healthcare power of attorney. Each participant met the criteria of over the age of 18 and had a CVC inserted and will remain in place for greater than 72 hours. There were no coerced participants since an informed consent was present for each. The Institutional Review Board approved this study. Data Collection
This experimental, randomized, controlled trial, was conducted at three university affiliated teaching hospitals in ICU units. There was a total of 242 patients that had a CVC inserted for greater than 72 hours. The two independent variables included the use of chlorhexidine on 125 patients vs. the use of povidone-iodine on117 patients as cutaneous antisepsis. The dependent variables were the outcomes; infection or no infection. Method and Rationale
The study required use of a standardization protocol when a catheter was inserted or the site cleaned with a dressing change. The catheter insertion sites were inspected every 72 hours for signs of erythema and purulent drainage. If erythema and purulent drainage were present, it was considered an “exit site infection” (Humar et al, 2000). Upon removal of the CVC the catheter tip was cultured. Catheter-related sepsis was determined if the organisms on the catheter tip matched organisms in the patients bloodstream. During dressing changes of the CVC, “quantitative exit-site cultures”(Humar et al, 2000) were taken from the skin around the insertion site. To maintain uniformity in culturing at the site, a 5cm by 5cm template was placed over the insertion site to allow an exact area within which to swab for bacteria. Bacteremia was defined by a single positive blood culture. Time Period
Data was collected from hospitalized participants in the ICU with a CVC in place greater than 72 hours over a one year period. Data Management and Analysis
According to the researchers, Humar et al, statistical analysis of the two groups were done with “the Mann-Whitney U test for continuous data and the chi squared test for categorical data” (2000). The researchers based their hypotheses on a referenced study by Maki, (1991) comparing povidone-iodine, alcohol and chlorhexidine for CVC infection prevention. The researchers hypothesized, “a 75% decrease on both outcomes in the patients in the chlorhexidine group”.
The collection of the data could not be blinded in the case of the CVC insertions due to chlorhexidine is clear, and povidone-iodine is brown. However, the microbiology team were blinded in regards to which group the participants were assigned. This study had strict data collection methods to help reduce any possible bias. Findings/Interpretation of Findings
The researchers of this study found there to be no significant difference in the infection rates between the chlorhexidine or povidone-iodine groups. The finding of this study are based upon a sample size of 242 participants from ICU’s. In order for this study to be valid and applied to future nursing practice, a much larger sample size and additional departments would need to be represented to create a valid application to be applied to a more generalized population. Limitations
Limitations, as defined by Burns, are “theoretical and methodological restrictions in a study that may decrease the generalizability of the findings”(2010), in this study were addressed by the researchers as a limited sample size due to the fact the CVC line had to be inserted for >72 hours. That was not always the case and 35% of the original study enrollment had to be disqualified. The disqualified participants did not present a bias to the results of the study due to disqualification was equal in both groups. The second limitation was in choosing the participant sample. Unconscious or intubated patients may not have been asked due to the degree of their illness. Strengths
The strength of the study was the the strict method in which possible bacteria were collected and the confirmation by molecular techniques. Findings for Nursing Practice
The researchers did not make any suggestions for application to nursing practice. The findings of this study were inconsistent with the previous studies referenced. More research needs to be done prior to changes in practice taking place. Conclusion
The findings of this study were inconsistent with the previous studies referenced (Maki,1991). This is an important topic in regards to patient safety and cost for treating unnecessary infections. Further research to reduce potential central venous catheter site infections needs to be done prior to changes in practice taking place.
Burns, Grove. (2011). Understanding Nursing Research (5th ed). W.B. Saunders Company.
Retrieved from http://evolveebooks.elsevier.com/books/978-1-4377-0750-2/outline/0
Humar, A., Ostromecki, A, Direnfeld, J., Marshall, J., Lazar, N., Houston, P., Boiteau, P., Conly, J. (2000). Prospective randomized trial of 10% Povidone-I versus 0.5% Tincture of Chlorhexidine as cutaneous antisepsis for prevention of central venous catheter infection. Clinical Infectious Diseases, 31(4), 1001-1007. Retrieved from http://www.jstor.org/stable/4461351