The feasibility of spinal anesthesia with sedation for laparoscopic general abdominal procedures in moderate risk patients.
Academic Article
Overview
abstract
BACKGROUND: One of the major advantages of laparoscopic surgery is minimizing postoperative morbidity. The previous limitations to the use of spinal anesthesia in laparoscopic surgery were the limited work space, high failure rate, more intra-operative morbidity and significant arterial blood gas alterations. However, the addition of a small-dose Ketamine infusion to propofol might provide a suitable sedative combination to be used with high spinal anesthesia, producing titerable sedation, increased hemodynamic stability, and minimal respiratory depression. PATIENTS AND METHODS: At KFSH & RC Hospital, after Ethical Committee approval and informed written consent, 18 ASA III patients scheduled for various laparoscopic abdominal procedures were enrolled. Exclusion criteria consisted of ejection fraction below 45% and or peak expiratory flow rate and forced vital capacity of less than 65% of predicted values. Following oral premedication with midazolam 7.5-10 mg 30 min preoperatively, spinal anesthesia was conducted by bupivicaine 0.75% 3-3.5 ml at L3-4, in the lateral position to reach a sensory level at T4. Sedation was started by intravenous injection of 0.4 mg/kg propofol and 0.1 mg/kg ketamine prior to spinal anesthesia. This was followed by infusion of 1.0-1.5 mg/kg/h and 0.3-1.0 mg/kg/h. of the same drugs respectively. The sedation requirements were adjusted to keep the patient sleepy with conservation of airway reflexes at level 3 on a 5 point sedation score. Heart rate, respiratory rate and SpO2 were monitored, together with direct arterial blood pressure monitoring and arterial blood gas analysis through arterial cannulation. Postoperative first time call for analgesia, total morphine consumption during the first hour and incidence of complications were recorded. Twenty Four hours later, surgeons' and patients' satisfaction were obtained and recorded. RESULTS: Heart rate and mean arterial blood pressure were significantly decreased after spinal anesthesia and intra-peritoneal insufflations of CO2, with significant increase in arterial carbon dioxide tension accompanied by increase in the respiratory rate. The increase in respiratory rate led to gradual decrease of CO2 level down to near the pre-operative PaCO2 values. However, there was insignificant decrease in oxygen saturation throughout the intra-operative time. Postoperatively there were excellent surgeon and patient's satisfaction. Only one patient regained sensation before completion of surgery and sedation was deepened to level 5 sedation score. The mean surgical time was 98.5 +/- 21.4 min while the mean anesthesia time was 117.7 +/- 20.1 min. First mean time call for analgesia was 50 +/- 8 min. 7/18 patients required single dose of morphine of 4 mg during the 1st hour postoperatively. CONCLUSIONS: The addition of a sedative combination of ketamine and propofol to spinal anesthesia was found to be safe and efficient from both the anesthetic and surgical point of view, especially for sick patients with intermediate clinical predictors.
