Drug preparation
Bradycardia, bradycardia, tachycardia, shock, loss of consciousness, postoperative nausea and vomiting, hypotension, hypertension
SHOCK, HYPOTENSIVE EPISODE, HYPERTENSION, CONTRACTIONS
Ketofol-1:1 group: 10 mL propofol (Propofol 1%, 10 mg/1 ml, FRESENIUS KABI DEUTSCHLAND GmbH, Deutschland) was mixed with 2 mL ketamine (Ketam 50 mg/mL, EPICO, Cairo, Egypt) and then diluted to a total volume of 20 mL to have a final concentration of 5 mg/mL propofol and 5 mg/mL ketamine.Ketofol-1:3 group: 15 mL propofol (150 mg) was mixed with 1 mL ketamine (50 mg) and then diluted to a total volume of 20 mL to have a final concentration of 7.5 mg/mL propofol and 2.5 mg/mL ketamine.Preoperatively, a trained anesthetist assessed the patients regarding the fasting hours, medical history, medications, laboratory investigation, as well as the patient’s airway.In the operating room, electrocardiogram, pulse oximetry, and non-invasive blood pressure monitor were applied. After obtaining vascular access, slow intravenous 4 mg dexamethasone (DEXAMETHASONE 4 mg/mL – MUP, Medical Union Pharmaceutical, Cairo, Egypt) was given for prophylaxis against postoperative nausea and vomiting and for its analgesic property. In the supine position, baseline blood pressure was recorded as the average of three consecutive readings with difference < 10% in the systolic blood pressure.Before induction of anesthesia for all study patients, volume assessment was done by measuring the baseline pulse pressure then giving a fluid challenge of 4ml/kg over 10 min. If the pulse pressure increased by > 15% of baseline, the patient was considered to be fluid responder, and the fluid challenge was repeated untill the increase in the pulse pressure was < 15% of baseline.After 3-minutes preoxygenation, patients in the two groups received 1 mg/kg lidocaine in a separate syringe (Lidocaine Hydrochloride 2%, Sunny Pharmaceutical, Cairo, Egypt) plus 0.15–0.20 mL/kg of the prepared admixture until achieving clinical loss of consciousness (defined as no response to auditory command and the disappearance of a patient’s eyelash reflex).After loss of consciousness, succinylcholine 1 mg/kg (Succinylcholine Chloride Injection 500 mg/5mL, Misr Co. for Pharm. Ind. S.A.E.) was administered over 5 s, and tracheal intubation was done through direct laryngoscopy after 60 s.The intubation conditions were graded by the same anesthetist who performed intubation. The assessment included 1- ease of laryngoscopy (easy: jaw relaxed, no resistance to blade insertion; fair: jaw not fully relaxed, slight resistance to blade insertion; difficult: poor jaw relaxation, active resistance of the patient to laryngoscopy), 2- vocal cord position (easy: abducted; fair: intermediate/moving; difficult: closed), and 3- reaction to insertion of the tracheal tube and cuff inflation (Diaphragmatic movement/coughing) (easy: none; fair: one to two weak contractions or movement for less than 5 s; difficult: more than two contractions and/or movement for longer than 5 s).The intubation condition was graded as excellent if all criteria are excellent, good if all criteria are either excellent or good, or poor if there was any criterion graded as poor [When the trachea was intubated, mechanical ventilation was applied to obtain peripheral oxygen saturation > 95% and end-tidal COAny episode of hypotension (mean arterial pressure < 70 mmHg) was managed by a 5-mcg norepinephrine bolus (Norepinephrine 4 mg/4mL, Sunny Pharmaceutical, Cairo, Egypt), which was repeated if hypotension persists for 2 min).Hypertension and tachycardia were defined as mean arterial pressure or heart rate > 120% of baseline, respectively. Persistent hypertension (blood pressure increasing after one measurement) was managed by intravenous 0.25 mg/kg propofol. Bradycardia (heart rate < 50 bpm) was managed by 0.5 mg of intravenous atropine.After skin incision, hemodynamic and anesthetic management was according to the attending anesthetist discretion.The primary outcome was total norepinephrine requirements during the period from induction of anesthesia until 16-minutes after intubation.Secondary outcomes were incidence of post-induction hypotension, severe post-induction hypotension (mean arterial pressure < 60 mmHg), hypertension, bradycardia, and tachycardia during the period from induction of anesthesia until 16-minutes after intubation. Mean arterial pressure, heart rate was recorded at baseline, immediately after induction, after intubation, then every 2-minutes for 16-minutes after intubation. The Number of hypotensive episodes per patients, intubation condition (the number of patients with excellent, good, and poor intubation conditions), intubation time (time from insertion of the laryngoscope into the mouth until its removal after tracheal intubation), total ketofol volume, and total propofol and ketamine dose per weight.Age, sex, weight, body mass index, American society of anesthesiologists-physical status, shock index, and preoperative fluid volume were also recorded.