Materials and methods
bradycardia, nausea, LBW, fasting blood glucose, tachycardia, Postoperative nausea and vomiting, HTN, vomiting or retching, hypoxia, vomiting, NCT04576975, pain, hypotension, Tachycardia, PONV, normocapnia, NRS
MUSCLE RELAXATION, NEUROMUSCULAR BLOCKADE, POSTOPERATIVE COMPLICATION, AIRWAY OBSTRUCTION, HYPOXIA, HTN, EVENTS, RESPIRATORY DEPRESSION
This prospective, randomized, double-blinded, three-armed, controlled trial was registered at clinicaltrial.gov (NCT04576975) on October 6, 2020, and has been reported according to the CONSORT guidelines. The study was approved by the Research Ethics Committee of the Faculty of Medicine of Ain Shams University (FMASU MD 108 /2020) on June 14, 2020. All procedures were conducted in accordance with the tenets of the 2013 Declaration of Helsinki.Based on a previous study [After ethical approval, patients who were scheduled for elective laparoscopic sleeve gastrectomy were interviewed by a team member. The inclusion criteria were patients aged 21 to 45 years of both sexes, with a body mass index (BMI) > 35 kg/mBaseline data on age, sex, BMI, and type of surgery were obtained. All tests (fasting blood glucose, HbA1c, thyroid profile, complete blood count, kidney and liver function tests, chest radiography, and electrocardiography) were performed according to our hospital’s protocols and reviewed before the day of operation. Upon entering the pre-anesthesia unit, the patients were premedicated with intravenous (IV) midazolam (20 µg/kg total body weight [TBW]) and IV atropine (0.015 mg/kg lean body weight [LBW]). Patients were randomly divided into the following three groups:
Ketamine group received a bolus dose of ketamine (Sterop, Brussels, Belgium) (0.3 mg/kg ideal body weight [IBW]) diluted with 0.9% normal saline (NS) and infused over a 10-min period using a 20-mL syringe before induction, followed by an infusion of ketamine (10 mg/mL, 500 mg vial diluted in a 50-cc syringe) at a rate of 0.3 mg/kg/h until 10 min before the end of the surgery.Dexmedetomidine group received a bolus dose of dexmedetomidine (Precedex®; Hospira, Birmingham, AL, USA) (0.5 µg/kg IBW) diluted with 0.9% NS and infused over a 10-min period using a 20-mL syringe before induction, followed by an infusion of dexmedetomidine (4 µg/mL, 200 µg vial diluted in a 50-cc syringe) at a rate of 0.5 µg/kg/h until 10 min before the end of the surgery.Control group received a bolus dose of 0.9% NS over a 10-min period using a 20-mL syringe infused before induction, followed by an infusion of 0.9% NS (50 mL in a 50-cc syringe).General anesthesia was induced with intravenous lidocaine (0.5 mg/kg IBW), propofol (1.5 mg/kg LBW), fentanyl (1.0 µg/kg TBW), and rocuronium (1.1 mg/kg IBW) for rapid-sequence endotracheal intubation. There were no cases of failed intubation in our cohort. Rocuronium was given every 30 min, and its effect was assessed by neuromuscular blockade monitoring keeping the train-of-four ratio between 0 and 1. General anesthesia was maintained with sevoflurane in an oxygen and air mixture guided by a bispectral index score between 40 and 60. Patients were mechanically ventilated with the maintenance of normocapnia (end-tidal COIf hypotension (defined as a mean arterial pressure [MAP] < 20% of baseline shown by two consecutive readings within 5 min, not responding to a 1% decrease in the inspired sevoflurane concentration) occurred, a crystalloid fluid incremental bolus (20 mL/kg IBW over 20 min) was administered, and then ephedrine was administered in 6-mg increments. For bradycardia (defined as a heart rate [HR] below 60 mmHg for ≥ 1 min), atropine 0.5 mg was administered as determined by the anesthesiologist.Intraoperative pain was defined as the development of HTN and tachycardia despite adequate anesthesia and muscle relaxation. HTN was defined as an MAP of > 20% of baseline on two consecutive readings within 5 min. Tachycardia was defined as an HR of > 20% of baseline for 5 min. A rescue dose of fentanyl was administered in increments of 0.5 µg/kg TBW. The intraoperative total fentanyl dose for each patient was calculated.Upon awakening, the patient received sugammadex (2 mg/kg) with a repeated dose of 4 mg/kg after 5 min if needed for muscle relaxation. A record of “time to extubation,” which was defined as the time taken for tracheal extubation after the discontinuation of anesthesia, was made for every patient.All patients were monitored postoperatively in the post-anesthesia care unit and ward. Sedation was assessed using the modified observer’s assessment of alertness/sedation scale (MOASS) (Table 
Modified observer’s assessment of alertness/sedation scalePostoperative pain was assessed using the numerical rating scale (NRS), with scores varying from 0 (no pain) to 10 (worst pain). The patients were informed preoperatively about the use and values of the NRS. The NRS score was recorded at 0, 30, and 60 min and 2, 6, 12, and 24 h after surgery.All patients received 1 gm of IV paracetamol (Perfalgan®; Bristol-Myers Squibb, Munich, Germany) every 6 h for 24 h postoperatively. In addition, a rescue dose of 4 mg of IV morphine with a minimum 6-h interval was administered between doses if the NRS score was ≥ 4, if needed. The total doses of morphine were calculated.All patients were assessed for PONV using the PONV intensity scale (Table 
Postoperative nausea and vomiting intensity scaleHave you experienced a feeling of nausea (“an unsettled feeling in the stomach and slight urge to vomit”)?If yes, has nausea interfered with activities of daily living, such as getting out of bed, moving in bed, walking, eating, and drinking?*Count distinct episodes: several vomiting or retching events occurring over a short period (e.g., 5 min) should be counted as one vomiting or retching episode; otherwise, these events should be counted separately [Postoperative complications (airway obstruction, hypoxia, severe nausea, respiratory depression, and vomiting) were recorded.Data were coded, tabulated, and analyzed using SPSS software version 16.0 (SPSS Inc., Chicago, USA) for Windows. Continuous variables were presented as mean (standard deviation) or median (Q3-Q1) and were compared using one-way analysis of variance or the Kruskal-Wallis test. Categorical variables were presented as frequency (%) and were compared using the chi-square test. Multiple pairwise comparisons were performed using the Tukey honestly significant difference test, Mann–Whitney test, or chi-square test. A P-value of less than 0.05 was considered statistically significant, and Bonferroni correction was applied when necessary.