Patients undergoing any type of elective cardiac surgical procedure requiring CPB will be
randomly assigned into one of the following groups using computer generated codes
(patients in each group):
Preoperative assessment will be done to all the patients who were going to join this
study before reaching the pre induction room.
The assessment will include:
Full History taking.
Full examination including the airway assessment. Checking the lab results (complete
blood picture, prothrombin time, partial thromboplastin time, liver functions and
viral markers and specially kidney function tests) and radiographic studies
ECG and EChO
On reaching the pre-induction room, the following will be done for each patient included
in the current study:
Inserting a secured intravenous (I.V.) access in a sterile technique.
Antibiotic will be given I.V. after sensitivity test is done.
Anti-stress medication (e.g. lansoprazole 60 mg) will be given I.V. slowly diluted
in a 20 ml normal saline to be repeated every 12 hours (Avner et al., 1995).
Sedation will be given in the form of 1-2 mg of Midazolam.
Attaching a monitor (pulse oximetry, non-invasive blood pressure, 5-lead ECG) till
the patient enter the OR with recording the initial vital data.
After lying of the patient down on the OR table:
Basic monitoring leads (5-lead ECG, pulse oximeter, invasive blood pressure IBP)
will be attached to the patient with recording the basal vital data.
I.V. crystalloid ringer solution will be started and maintained all through the
operation.
An arterial 20G vygon cannula will be inserted in the radial artery of the
non-dominant hand, and connected to an arterial dome through a non-compliant A-line.
Thus, obtaining arterial blood gas (ABG) samples during the operation, and
continuous beat-to-beat blood pressure monitoring (Pierre et al., 2018).
Pre-induction oxygenation with 100% oxygen will be done for 1 minute.
Induction using an opioid-based general anesthesia will be done by giving 0.03 -
0.05 mg/kg of Midazolam (Midathetic® Amoun Pharm, a 5 mg/1 ml ampoule) (Lingamchetty
et al., 2019), 1 mg/kg of Propofol (Propofol 1% Fresenius®, a 200 mg/20 ml ampoule)
(Folino et al., 2022), 3-5 mcg/kg of Fentanyl (Fentanyl hameln® Sunny Pharmaceutical
Company, a 100 mcg/2 ml ampoule) (Bailey et al., 1985), 0.5-0.6 mg/kg of Atracurium
(Atrabesylate® EGY Pharm, a 50 mg/5 ml ampoule) (Chalermkitpanit et al., 2020), and
supporting the patient's ventilation for 2-4 minutes.
Tracheal intubation will be performed by an experienced anesthesiologist. A lubricant
will be used on the tip of the endotracheal tube (ETT) before intubation
Mechanical ventilation will be controlled by adjusting the current volume to 8-10
mL/Kg and frequency of ventilation of up to 12-14 breaths/min to maintain
normocapnia: end-tidal pressure CO2 (ET CO2) at the level of 35 ± 5 mm Hg and
respiratory frequency, oxygen: air 50%: 50%
An ultrasound-guided insertion of triple line 7 Fr. Central venous catheter (CVC) in
the right/left internal jugular vein will be done after full sterilization with
chlorhexidine with contact time 1-2 minutes and sterile draping to the site of
insertion.
A temperature probe will be applied to the patient
Anesthesia is going to be maintained using isoflurane (1.0 - 1.5%), oxygen (1-2
lit/min) and air (1-2 lit/min), by means of a circuit with CO2 absorption.
Neuromuscular blockage is going to be maintained by Atracurium infusion with a rate
0.3 mg/kg/hr. to guarantee that the patient was fully paralyzed all through the
surgery.
Patients will be randomized to receive either dexamethasone or placebo treatment.
Dexamethasone (1mg/kg of body weight, with a 100mg maximum) or placebo will be
administered as a single intravenous injection after induction of anesthesia, but before
initiation of CPB.
The study drug will be supplied in packaged ampoules, each assigned to a unique study
number. Packages and ampoules of dexamethasone and placebo will be identical and contain
an equal volume of either a dexamethasone (Dexamethasone - MUP 8 MG / 2 ML (Dexamethasone
Sodium Phosphate) solution or normal saline, respectively. The research pharmacist, will
prepare and deliver batches of (60) ampoules. When a consenting patient arrive in the
operating department, a packaged ampoule will be taken from the batch.
When the ampoule is opened and the study drug is administered, the patient is considered
randomized and the corresponding study number will be assigned to that patient. Patients,
caregivers, and researchers will be unaware of study group assignment.
• Postoperative settings: After surgery, patients are transferred to the intensive care
unit (ICU) and will be weaned from mechanical ventilation when there was no excessive
ongoing blood loss and patients were cooperative and hemodynamically stable.
Perioperative serum glucose is regulated according to local sliding scale protocols.
Post-operative serum creatinine, GFR will be obtained once daily, and hourly urine output
will be followed for 7 days, acute kidney injury is defined according to the RIFLE
criteria as an increase in postoperative serum creatinine of at least 2 to 3 times the
preoperative baseline value or GFR decreased >25%, or urine output < 0.5 mL/kg/h >12 h,
and failure defined as a serum creatinine level of more than 4 mg/dL associated with an
acute increase of serum creatinine of at least 0.5 mg/dL (Bellomo et al., 2004).
Other measurements will be included as a secondary outcome as: the time used to wean of
ventilator, the duration of ICU stay and duration till discharge from hospital, incidence
of developing post-operative infection, glucose level will be obtained hourly for the
first 24 hours then every 4 hours till ICU discharge then twice daily till completion of
the 7 days of the study, the incidence of developing diabetic ketoacidosis (DKA) or
hyperglycemic hyperosmolar coma also will be followed up.