This randomized controlled clinical trial adheres to CONSORT guidelines and was performed on 150 patients in Ramathibodi Hospital from May 2018 to March 2019. The study was approved by the Ramathibodi Ethics Committee (ID 03-61-10, Date of approval: April 25, 2018). Patients who had been selected were informed by the researchers about the research methods, after which they gave their consent and the patient consent was written. Informed consent was obtained from all participants in the trial. The trial was registered at clinicaltrials.in.th (TCTR20180608004, Date of registration: June 06, 2018). The first case enrolled to the study was on May 15, 2018. A late registration was without any changes in the study protocol.
Eligible patients included those >15 years of age who were scheduled to undergo elective cardiac surgery, required CVC insertion at the internal jugular vein in the operating room, and were scheduled for transfer postoperatively to the cardiac intensive care unit (ICU). Exclusion criteria included refusal to participate, the presence of signs of infection or sepsis, and/or a history of atopic disease.
Demographic characteristics, including the risk of a bleeding tendency, were collected at enrollment. The bleeding tendency is defined in Table 1.
We randomly assigned patients into two groups via block-of-four randomization sequences using a computer-generated randomization website (http://www.sealedenvelope.com). Allocation concealment was done by using sealed envelopes. Blinding was not possible in this study design. The standard control (SC) group comprised patients who underwent routine CVC insertion by an anesthesiologist or anesthesia department resident under supervision. The CVC was then fixed by suturing with nylon or silk. The wound was covered with 1-cm gauze and a transparent dressing with Tegaderm (not Dermabond). In the topical tissue adhesive (TA) group, the patients underwent routine CVC insertion (same as that for the SC group) but Dermabond was applied to the catheter at its insertion site before applying the 1-cm gauze and Tegaderm (as in the SC group). We assigned the responsible anesthesiologist to the protocol.
All patients underwent general anesthesia and standard monitoring, including electrocardiography, pulse oximetry, noninvasive blood pressure measurements, end-tidal carbon dioxide monitoring, and invasive monitoring such as arterial blood pressure measurements.
The technique, time period of CVC insertion(s) (before vs. after anesthesia induction), number of CVC per location, or medications for inducing and maintaining the patient under general anesthesia depended on the decisions of the clinician who assessed the patient preoperatively and attended him or her during the maintenance phase of the operation. The CVC insertion technique included an ultrasonography-guided or landmark technique. After the operation was completed, the clinician who was accountable for the patient to the end of the operation, evaluated the CVC insertion site to determine if there was any pericatheter bleeding before transferring the patient to the cardiac ICU. If there was some pericatheter bleeding, whether to change the dressing was decided by the clinician who had no role in study design or data analysis. Data were recorded during the operative period and continued, along with monitoring the postoperative bleeding risk. After admission to the cardiac ICU, the patient’s CVC was assessed and attended to by the ward nurse and clinicians to evaluate if there was pericatheter bleeding and, if so, how much, as well as watching for any signs of infection.
The primary outcome of the study was having to change the dressing immediately postoperatively due to pericatheter leakage. The secondary outcomes were the number of dressings used, total dressings per catheter-day, and a composite outcome of catheter failure within 3 days, which included failed fluid infusion via the catheter, hematoma development, and/or infection. A flowchart of the study’s progression is shown in Figure 1.
The sample size was calculated based on a recommendation for a pilot randomized trial16. The sample size of 150 for standardized the extra small effect sizes (£0.1) are recommended for a trial designed with 90% power and two-sided 5% significance.
Intention-to-treat and per-protocol analyses were performed. The intention-to-treat analysis included all patients who fulfilled the randomization process. For the per-protocol analysis, we excluded patients who switched treatment during the trial before achieving the primary outcome (n=7). There were no missing data.
Descriptive analysis was performed using means, medians, standard deviations, and interquartile ranges for continuous variables, and number counts with percentages for categorical variables. Categorical variables were compared using the 𝜒2 test. The normal distribution of each data set was confirmed using the Kolmogorov–Smirnov test. The t test was used to compare data with a parametric distribution. If the data were not normally distributed, the Mann–Whitney U test was employed. Statistical analysis was carried out using SPSS 20.0 software (IBM SPSS Statistics for Windows, Version 20.0; (IBM Corp., Armonk, NY, USA). A significance level of P < 0.05 was used for all statistical analyses. If the results or baseline characteristics showed a significant difference, a multiple logistic regression was conducted to determine if it was an independent predictor associated with immediate postoperative dressing change.