Patient selection
Inclusion criteria
All TBI patients admitted directly or transferred to the intensive care units of participating hospital will be evaluated for eligibility for entry into the randomized clinical trial. Preliminary eligibility criteria are summarized in Table 1.
Exclusion criteria
Patients meeting all preliminary eligibility criteria are considered potentially eligible for the study. Patients are screened for the presence of any specific exclusion criteria which would preclude study entry. These exclusions are designed to eliminate patients for whom participation may be dangerous or patients with serious medical disorders whose impact on operative outcome may obscure the importance of nutritional, clinical and inflammatory factors. These are summarized in Table 2.
Default criteria
Once randomization has taken place, patients will be removed from the study only for the following reasons: 1) patient’s or physician’s request, 2) significant change in patient's treatment process, 3) create any exclusion criteria, 4) sensitivity to PYC supplementation.
Sample size
Sample size calculations were based upon Luzzi et alʼ s study (34) which showed the mean CRP change in the treatment group was 60% and in the control was unchanged or up to a maximum of 15%. Based on the formula for comparing two proportions of a qualitative attribute from two independent statistical societies, the sample size was determined as 25 individuals in each group, (α= 0.05, β=0.1, the power of study is 90%). Assuming a probable drop out the sample, 30 patients in each group will be considered.
A study evaluating the effect of PYC on IL-6 and TNF-α in TBI was an animal study (30) and inappropriate for the human sample size calculation. Therefore, we used CRP as an inflammatory factor to calculate the sample size. However, for more certainty, we calculated the sample size according to Hakumat Rai et al study (35) based on IL-6 change in TBI patients. Based on the mean difference between the two groups for IL-6 and error level of 5% and power of 85% the total sample size calculated was 46. With a 10% probability of drop out during the study, the total sample size was 50 (25 in each group).
Study procedures
The university's executive committee will oversee the project's implementation and progress, information security, safety of trial participants, and scientific impact assessment. Also this committee will review data from the trial. The trial sponsor will undertake auditing of the trial procedure.
Randomization and masking
We will randomly allocate eligible patients on enrolment (1:1) to either the control group or the intervention group. The randomization list of unique patient identifiers is generated by the computer-generated random block size site. The classification is based on age (18 to 40 and 40 to 65 years old), gender (male / female) and APACHEII score (0 to 35 and 35 to 71) using quadruple blocks.
Nutritionists or clinicians will keep the sealed opaque envelope containing the unique patient identifier and the study group allocation in a locked cabinet in the study laboratory. They will be opened by the second nutritionist. Investigators, all study staff hospital attending clinical teams, and patients will be masked to the study group allocation.
Intervention
A pragmatic (36), parallel-group, double-blind, randomized controlled trial (table 3) will be conducted. We will enroll 60 patients who are admitted to ICU at a university hospital in Tehran, Iran. All participants or their first-degree relatives will need to provide informed consent to the clinician before participating.
Participants will be randomly divided in two groups. The method of randomization and masking are explained above. At the first visit, baseline data will be gathered and the intervention group will receive PYC supplement (OLIGOPIN) in the form oral capsules containing 50 mg French maritime pine bark extract plus 130 mg Microcrystalline Cellulose. OLIGOPIN powder of each capsule will be dissolved in 10 ml deionized water and given to patients via gavage (3 capsule per day) for 10 days.
Control group will receive oral capsules containing 130 mg Microcrystalline Cellulose with 10 ml of deionized water via gavage (3 capsule per day) for 10 days.
The capsules will be given by the investigator to the patients by gavage, so fidelity to the intervention will be strong. However for more certainty, at the end of each day, the number of capsules remaining for each patient will be checked. In order to control the confounding effect of food intake, both the control group and the intervention group receive the standard formulas based on their daily required energy via enteral root feeding.
Possible risk assessment of intervention
Initially an intervention with a dose of 150 mg of PYC will be started for 10 patients, and in the absence of clinical complications and observing the expected effect on the reduction of inflammatory markers, the same dose will be continued. Otherwise, it will be reduced to 100 mg, if there is any adverse effect. There have been no reports of serious adverse event in any clinical trials or commercial use of OLIGOPIN. However, these patients will be regularly evaluated biochemically and clinically each day, and the liver function tests including serum levels of ALT (alanine aminotransferase) and AST (aspartate aminotransferase) will be checked. If there are any potential complications from intervention or, if the physician determines that the intervention should be discontinued, the supplements will be immediately removed from the patient's enteral nutrition.
Data collection
Data will be collected at four main times: at the base line, at 5th day of intervention, at 10th day of intervention and at the 28-day follow-up visit. At the base line demographic characteristics are gathered via a questionnaire. Anthropometric assessment including height (via ulna length), weight (by using portable scale “Balas”), body mass index and body composition (by using bio impedance device “Inbody”) will be measured at the base line, 5th day and at the end of intervention.
In order to evaluate inflammatory and oxidative stress markers, 10 cc of venous blood will be taken from each patient at the base line, at the 5th day and at the end of the study. The serum sample will be isolated and used to measure the markers via ELISA kits. APACHE ІІ (for assessment of clinical status of patients) and Nutric questionnaires (for assessment of nutritional status) will be filled out at the base line, 5th day and the end of study. SOFA questionnaire (for assessment of organ failure) will be filled out every other day. The mortality rate will be asked by phone within 28 days of the start of the intervention. A SPIRIT diagram of the recommended content for the schedule of enrolment, interventions, and assessments is shown in figure 1.
Data management
Specially designed forms will be completed by study staff at each time point, and scanned, verified and committed to a local site database within 48 h of completion. Completed forms will be stored as the source documentation in a locked cabinet, with access restricted to specified study team members. The forms will be identified by a unique participant ID number and will not contain any patient identifiable information. Queries based on data in the database will be generated daily, including date, range and logic checks.
Outcomes
The measurable outcomes are summarized in table 4.
Statistical methods
The trial profile will be summarized using a CONSORT flow chart, including reasons for non-eligibility and non-enrolment (37). The objective of this clinical trial is to determine if PYC supplementation improves clinical and nutritional outcomes in TBI patients admitted in ICU or not. To answer this question, the outcomes of patients receiving PYC supplement will be compared with the outcomes of patients receiving placebo.
All analyses will be conducted by initially assigned study arm in an intention-to-treat analysis, and adjusted for randomization site. Thus, all randomized patients who will receive at least one dose of study treatment and who will have both a baseline and at least one post baseline measurement will be analyzed. The data will be expressed as mean ± SD. Statistical analyses will be conducted with SPSS version 19 (SPSS Institute, Chicago, Ill). Chi-square test will be done for categorical variables. T test will be done to assess the statistical significance of the continuous variables. Comparable nonparametric test (Mann-Whitney U test) will be substituted when tests for normality and equal variance failed. A value of P 0.05 will be used as a criterion for statistical significance. Survival analysis will be performed with log-rank test. The study design flow diagram is summarized in figure 2.
More details about the statistical analyses plan is presented in appendix.