The aim of this study was to try to reduce the required dose of etomidate used in anesthesia for upper endoscopy and colonoscopy in critically ill cardiac patients who complain of severe anemia in cardiac intensive care units by using a low dose of ketamine, which helps to reduce the side effects of etomidate, the most important of which is its suppressive effect on the adrenal gland and the secretion of cortisol in such critical cases, while maintaining hemodynamic stability, and the patient's satisfaction.

This Prospective Randomized Clinical Trial will be done in the period from November 2020 - October 2021, after approval of our local ethical committee, and based upon written informed consent, included sixty cardiac patients, ASA physical statuses III or IV, admitted in CCU and SICU, and scheduled for upper endoscopy together with colonoscopy for diagnosis and management of acute anemia.

The study will be performed in the CCU or SICU with the presence of all emergency equipment's. The gastroenterologist who performed the colonoscopies will be blinded from the type of drugs used for sedation.

All patients will receive a colonic preparation protocol before the operation, and bowel cleansing will be performed, and all patients will be fasting 8 hours before the procedures.

Anesthesia management:

After establishment of IV access, standard monitoring will be performed (noninvasive blood pressure, ECG, SpO2, and BIS using (Masimo) monitor).

Nasal cannula for oxygen (6 l/min) will be connected to all patients, then midazolam 0.03mg/kg IV as a premedication, and fentanyl 1µg/kg IV will be injected to all patients.

By the means of sealed envelope technique, patients will be randomly divided into two groups:

Group (E): Received Etomidate 0.2 mg/kg IV over 30 seconds, followed by 0.05 mg/kg IV and repeated when needed.

Group (KE): Received Ketamine 0.5 mg/kg IV over 30 seconds then Etomidate 0.1 mg/kg IV over 30 seconds, followed by 0.05 mg/kg IV and repeated when needed.

The additional dose of etomidate will be determined by the anesthesiologist to achieve 4-5 sedation level of Ramsay Sedation Scale or BIS above 60.

Complications during procedure will be considered and defined as:

1. Hypotension: decrease of baseline systolic blood pressure (SBP) >30%, or decrease of baseline diastolic blood pressure (DBP) >30%, and this will be treated by phenylephrine 100-200 µg IV boluses.
2. Bradycardia: decrease of HR < 50/min, and this will be treated by atropine 0.5 mg IV boluses.
3. Apnea: spontaneous breathing > 30 sec, or SpO2 < 85%, and this will be treated by assisted manual ventilation using AMBU bag and face mask.

During the procedure the level of sedation will be assessed every five minutes after administration of anesthetic drugs using Ramsay Sedation Scale (RSS) [18]: (1 = Anxious or restless or both, 2 = Cooperative, 3 = Responding to commands, 4 = Brisk response to stimulus, 5 = Sluggish response to stimulus, 6 = No response to stimulus), in addition to BIS.

The use of standard monitoring will be continued until the patients were fully awake. At the end of the procedure, total etomidate dose, the duration of the procedure, and the recovery time of the patients were recorded.

After full recovery and when the patients are alert enough to express their attitude regarding the intra-procedural events, they will be asked to score their level of satisfaction during the procedure in terms of recalling any painful or other undesirable intra-procedural events.

Patient's satisfaction level willbe assessed with a Likert five-item scoring system [19]:

(1 = Not satisfied at all, 2 = slightly satisfied, 3 = somewhat satisfied, 4 = very satisfied, and 5 = extremely satisfied).

Serum cortisol before and 6 hours after the procedure will be estimated in this clinical trial to calculate the percentage of suppression in both groups.

Statistical Analysis:

Sample size was calculated using: Calculator.net Home / math / sample size calculator. Sample size of 30 cases in each group was calculated to have at least an 80% power to detect the expected differences between the two groups with respect to the primary goal.

Group comparison willbe performed between groups E and KE to analyze differences. Mean, standard deviation (SD), median, frequency, and percentage (%) will be used in the descriptive statistics of the quantitative and qualitative data. Mann-Whitney U test will be used in the analysis of quantitative independent data. Chi-square test will be used to analyze qualitative independent data, and Fischer's test will be used when chi-square test conditions were not met. For comparison of the sedation score data, hemodynamic parameters and SpO2 values, the repeated measurement analysis will be used. P value <0.05 will be considered statistically significant. SPSS v23.0 program will be used for all the analysis.

Inclusion Criteria:

• - Age 18 - 65 years,
• ASA II-III
• Ejection fraction (EF) > 30%.

Exclusion Criteria:- Poor left ventricular function (ejection fraction < 30%).

• Recent myocardial infarction (last seven days),
• Patients with uncontrolled chronic disease (uncontrolled diabetes mellitus (DM) and hypertension),
• Known history of hypersensitivity to midazolam, fentanyl, etomidate, Or ketamine,
• Severe respiratory, hepatic or renal failure,
• History of neurological disorders or convulsions,
• In addition, any need for further anesthetic drug administration other than the study protocol was another exclusion criterion of this study.

All collected IPD

January 2022

IPD data will be available on request through email.

All participants including care provider and outcome assessors will unaware of group allocation.