Comparison of the Hemodynamic Effects of Ketamine - Dexmedetomidine (Ketodex) Versus Propofol-ketamine Admixture (Ketofol) During Induction of Anesthesia in Elderly: A Randomized Comparative Study

This study details the protocol for anesthetic induction and maintenance, allocating patients into Ketodex (KD) and Ketofol (KP) groups. Prior to anesthesia, a fluid challenge (4 mL/kg over 10 minutes) was administered to assess volume status, with repeated challenges until pulse pressure increased by less than 15% of baseline. For induction, all patients received 1 mg/kg lidocaine. KD patients then received 1 mg/kg ketamine + 0.5 µg/kg dexmedetomidine over 10 minutes, while KP patients received 0.15-0.20 mL/kg of a ketofol admixture. Loss of consciousness, defined by no response to auditory commands and absent eyelash reflex, led to the administration of 0.6 mg/kg rocuronium. After 2 minutes of mask ventilation, an endotracheal tube was inserted. Anesthesia was maintained with isoflurane (0.9-1% end-tidal), and Ringer's lactate solution was infused at 4 mL/kg/hour. Hemodynamic stability was rigorously managed: hypotension (mean blood pressure (MBP) ≤ 80% of baseline and/or MBP < 60 mmHg) occurring up to 15 minutes post-intubation or skin incision was treated with 5 µg norepinephrine boluses, repeatable every 2 minutes. Severe post-induction hypotension (MBP ≤ 60% of baseline) prompted 5 µg norepinephrine boluses every minute, with 1-minute interval blood pressure monitoring. Hypertension (mean arterial pressure > 120% of baseline) was managed with 0.25 mg/kg IV propofol, while bradycardia (heart rate < 45 bpm) was treated with 0.5 mg IV atropine. Blood pressure and heart rate were continuously monitored at specified intervals, with subsequent hemodynamic management left to the discretion of the attending anesthetist after 15 minutes post-intubation or skin incision.