The treatment of vitamin D deficiency in neurocritical ill patients (VITdAL-ICU) protocol is designed according to the CONSORT guidelines for randomized, clinical trial (RCT) (18). The protocol of this RCT is approved by Medical Ethics Committee of Mashhad University of Medical Science (IR.MUMS.MEDICAL.REC.1397.381) and is registered at the Iranian Registry of Clinical Trials under IRCT20180619040151N3. The flow diagram illustrates details of the current study protocol in Figure 1. Moreover, the study time framework for screening, supplementation and monitoring are described in Figure 2.
Study objectives and rational
The primary goal of the present study is to investigate the effect of daily intake of high dose vitamin D (Cholecalciferol) supplements (100000 IU) versus low dose vitamin D supplements (1000 IU) on mortality rate and inflammatory markers through a double-blind, randomized, controlled clinical trial on traumatic brain injury (TBI) patients. According to previous observational studies, TBI patients with vitamin D deficiency had higher mortality rate and neuro-inflammation in comparison with TBI patients with vitamin D sufficiency (15, 17). Also, as vitamin D deficiency is highly prevalent in critically ill patients, rapid normalization of this deficiency may be beneficial to these patients (7, 22, 23). For this reason, we hypothesized that rapid correction of vitamin D deficiency in TBI patients may improve inflammation and decrease mortality rate. This study will also evaluate seven secondary outcomes that may be influenced by vitamin D administration in neurocritical patients. In order to determine the effects of high dose vitamin D intervention 1) Glasgow coma scale (GCS), 2) time of final weaning 3) time of discharge from ICU 4) SOFA score (Sequential Organ Failure Assessment), 5) APACHE II Score (Acute Physiology and Chronic Health Evaluation II) 6) delirium severity and 7) parathyroid hormone (PTH) will be assessed in the treatment group compared to control group. The study participants will be recruited from adult wards at trauma referral hospitals namely Kamyab and Taleghani in Mashhad, Iran. This study is a phase II-RCT and it has started from August 2019 and will carry on for 5 months.
Eligibility criteria for TBI patients are listed below. Participants will be allocated into four equal blocks by random in two groups using an online randomization list.
1-Patients: traumatic brain injury adults aged 18-65 years’ old.
2-Admission to neurocritical care unit with Epidural hemorrhage (EDH) and subdural hemorrhage (SDH). Because, these two types of trauma are most prevalent in patients admitted to our intensive care unit.
3-Glasgow Coma scale 7-9
4-TBI patients with vitamin D (25-hydroxy vitamin D3) levels lower than 20 ng/ml
5-Recived informed consent from patient's parents or family members prior to intervention
1- Patients with hypercalcemia (Ca > 10.8 mg/dl)
2-TBI Patients who are NPO more than 48 hours or have started total parenteral nutrition (TPN).
3-Severe and active bleeding
4-Patients treated with inotropic and corticosteroid drugs.
5- Patients treated with therapeutic dose of any vitamins and minerals apart from the routine ICU protocol
6-Patients with body mass index (BMI) > 40kg/m2 and BMI < 17kg/m2
7-History of any disease such as autoimmune disorders, cancer, sepsis, infection, liver disorder, kidney disorder, diabetes, heart failure and metabolic diseases
8-Known pregnancy and lactation
9-Patients who are transferred from other ICUs after > 1week
Death before 7 days of traumatic brain injury patients
Request to stop the study by patients’ parents or family members
Patients treated with different medication protocol
If item 1 to 5 of non-entry criteria are met
Study design and setting
We will include 74 TBI patients with Epidural hemorrhage and subdural hemorrhage as diagnosed according to computed tomography scan (CT) or Magnetic resonance imaging (MRI) findings by the neurosurgeon. Patients will receive vitamin D (Cholecalciferol) drop (100000 IU) or 1000 IU identical control drop in a 1:1 ratio through random assignment method. Vitamin D drops are manufactured by Zahravi Company under good manufacturing practice (GMP). Each vial of vitamin D drop is produced to be dissolved completely in 1ml of extra virgin olive oil (Familia Company), through a nasogastric tube (NGT) for 5 days in TBI patients. Both high dose and low dose drops will have the same bottle, flavor and aroma to the blinded.
To calculate the sample size, in accordance with a previous study (7), interleukin 6 (IL-6) will be used as the main variable and the type one error is considered with an alpha of 0.05. We estimated 62 TBI patients with 80% power to detect an effect size of 0.5 for reduction of IL-6 between intervention and control groups as calculated with the formula shown below. Considering 20% dropouts in this study, the total sample size is estimated to be 37 participants in each group as calculated in below formula (7).
[Please see the supplementary files section to view the equation.]
Randomization and blinding
Block randomization method will be considered for this trial study. TBI patients will be randomized (in four blocks) into intervention group and control group based on a blinded randomization list generated by randomization and online databases for clinical trials (https://www.sealedenvelope.com) and will be managed by research director of Clinical Nutrition Department, Mashhad University of Medical Sciences. Patients will be allocated by random according to the severity of brain injury (GCS 7-8 and 8-9), type of brain injury (EDH and SDH) and gender to ensure match distribution of these factors in all four blocks. Given that ICU supervisor has no knowledge of which vial contains high dose or low dose of vitamin D, TBI patients will be randomized to group A or B. The label A or B on vials will be deleted by the research director before allocating the study supplements, thus the medication will appear similar to study researcher and nurses. The TBI patient’s study identification code will be documented and intervention group may only be determined by comparing the patient’s study number to the reference blinded list, which only research director will have access to until the trial is finished. Figure 2 indicates the SPIRIT schedule of evaluations and interventions.
To determine the normal distribution of variables, Kolmogorov-Smirnov test will be conducted. The analysis will be performed according to intention-to-treat (ITT) test. One-way analysis of variance (ANOVA) or multi-variable covariance analysis (ANCOVA) will be conducted to examine differences in severity of brain injury score (GCS), APACHEII score, SOFA score, delirium score and all variables at study baseline between the two groups. If the distribution of variables turns abnormal in this study, Kruskal-Wallis test will be performed to compare the case and control groups, and Wilcoxon test will be carried out for inter-groups comparison. The P values less than 0.05 will be considered statistically significant.
Primary efficacy endpoint
The primary efficacy outcome for this trial will be assessed by comparing the changes in vitamin D levels and inflammatory markers (IL-6, Monocyte Chemoattractant Protein-1 (MCP-1) and C - reactive protein (CRP)) between two groups. The rate of mortality in TBI patients until 28 days after admission (in ICU and regular ward) will be assessed in high and low dose vitamin D supplement groups. The impact of high dose versus low dose of vitamin D will be analyzed, with and without adjustment for age, sex, type of brain injury and severity of injury. If the results differ after adjusting for the variables, the results of both analyzes will be reported.
Secondary efficacy endpoints
All analyses will be conducted with and without adjustment for age, sex, type of brain injury and severity of the injury. Time to event analysis will be analyzed similarly as the primary endpoint. The secondary outcomes are listed below:
- Comparison of GCS score changes between intervention and control groups during intensive care unit stay
- Comparison of APACHE II and SOFA score between intervention and control groups during intensive care unit stay.
- Comparison of incidence of delirium between intervention and control groups during intensive care unit stay.
- Comparison of changes in PTH levels between intervention and control groups during intensive care unit stay.
- Comparison of time of discharge from intensive care unit in patients treated with high dose and low dose vitamin D groups (during the first 28 days of admission).
- Comparison of time to weaning from mechanical respiratory support in patients treated with high dose and low dose vitamin D groups (during the first 28 days of admission).
- Comparison of need for a tracheostomy between intervention and control groups during intensive care unit stay.
- Comparison of occurrence of infections among intervention and control groups during intensive care unit stay.
At the beginning of the trial, demographic information, anthropometric parameters (weight (bed scale, Balas company), (estimating height from ulna length), mid arm circumference (measured at the mid-point between the tip of the shoulder and the tip of the elbow), fat free mass, fat mass and (bioelectrical impedance analysis s10, InBody company), vitamin D3 status (25-hydroxy vitamin D3, ELISA kit) , IL-6 (ELISA kit) , MCP-1(ELISA kit), quantitative CRP (ELISA kit), PTH (ELISA kit) , Ca, APACHE II score, SOFA score and delirium score will be measured and repeated on day 7 and 14 after intervention in groups A and B. All drugs will be ordered daily upon physician’s request during ICU stay and will be recorded. For adjusting the effect of energy on final outcomes, based on ESPEN guideline for all patients 25kcal/ kg actual body weight energy is considered (19). Moreover, the total kilocalories and macronutrient delivered by enteral feeding will be calculated daily for all the participants. Blood samples (5mL) will be collected at baseline (ICU admission) and 7 and 14 days after intervention at 10:00 am. Blood sample will be taken from veins and centrifuged at room temperature, then stored at -20 °C. Finally, the samples will immediately be transferred with the cold box to a freezer -80 °C for future inflammatory cytokines measurements. All routine biochemistry, hematology and urine test, until day 14, will be measured after sampling in Kamyab Hospital lab, Mashhad, Iran. Serum IL-6, MCP-1 and CRP levels will be analyzed in the baseline and day 7 and 14 at Immunology Lab of Bu Ali Research Institute, Mashhad, Iran. In addition, in case of occurrence of infections (blood stream, the urinary tract, the gastrointestinal tract, wounds and lung) an internist specialist will take responsibility (20). A summary of the schedule of registration, supplementation, and study evaluation is shown in Figure 3.
Vitamin D deficiency treatment is required for patients with low vitamin D levels (< 20 ng/ml) . However, the primary side effect of Cholecalciferol supplementation is hypercalcemia (13). To prevent hypercalcemia in TBI patients, serum vitamin D and calcium levels are evaluated regularly, as adequate vitamin D levels are reached hypercalcemia is likely to be treated, therefore the intervention will be stopped (21). Moreover, to keep track of the patient's condition, daily vital signs and clinical examinations by neurosurgeon and ICU supervisor will be carried out and will be stopped if the patient’s condition deteriorates.