ABSTRACT
BACKGROUND AND OBJECTIVE: Magnesium administered before anaesthesia induction results in a significant reduction in intravenous anaesthetic consumption. The purpose of this study was to evaluate whether the dose of intravenous magnesium sulphate reduces the minimum alveolar anaesthetic concentration of sevoflurane for endotracheal intubation (MACEI) and skin incision (MAC), and attenuates haemodynamic responses. METHODS: We studied 60 patients who were scheduled for elective surgery. Patients were not premedicated before induction of anaesthesia and were randomly assigned to receive intravenous saline 0.9% (Group I, n = 20) or magnesium sulphate 30 mg kg(-1) bolus + 10 mg kg(-1) h(-1) continuous infusion (Group II, n = 20) or 50 mg kg(-1) bolus + 10 mg kg(-1) h(-1) continuous infusion (Group III, n = 20). RESULTS: Median and 95% confidence limits for sevoflurane MACEI were 2.68 (2.48-2.85), 2.88 (2.70-3.06) and 2.96 (2.70-3.16), and for sevoflurane MAC were 2.08 (1.76-2.40), 2.26 (2.08-2.47) and 2.40 (2.19-2.68) in Groups I, II and III, respectively. The differences in MACEI and MAC among groups were not statistically significant, except Group III in MAC study (P < 0.05). Mean arterial pressures and heart rate did not increase in Groups II and III after endotracheal intubation and skin incision. CONCLUSIONS: Magnesium sulphate administered before induction of anaesthesia increases MAC of sevoflurane and reduces cardiovascular responses to intubation.
Subject(s)
Anesthesia, General , Anesthetics, Inhalation , Hemodynamics/drug effects , Magnesium Sulfate/pharmacology , Methyl Ethers , Pulmonary Alveoli/metabolism , Adolescent , Adult , Anesthetics, Inhalation/administration & dosage , Double-Blind Method , Female , Humans , Intubation, Intratracheal , Magnesium Sulfate/administration & dosage , Male , Methyl Ethers/administration & dosage , Middle Aged , Monitoring, Intraoperative , Prospective Studies , SevofluraneABSTRACT
BACKGROUND AND OBJECTIVE: Patients having spinal anaesthesia with hyperbaric bupivacaine may become sensitive to sedative drugs but no data exists about any dose-related effect of the local anaesthetic on the sedative requirement. We aimed to investigate whether hyperbaric bupivacaine dose in spinal anaesthesia has any effect on midazolam requirements. METHODS: Sixty unpremedicated patients were allocated to three equal groups. Patients in Groups I and II received hyperbaric bupivacaine 0.5% 10 and 17.5 mg respectively for spinal anaesthesia and Group III was a control group without spinal anaesthesia. In Groups I and II, after the evaluation of sensory block, patients received intravenous midazolam 1 mg per 30 s until the Ramsay sedation score reached 3 (drowsy but responsive to command). In Group III, general anaesthesia was induced after sedation score had reached 3 using midazolam. The total dose of midazolam (mg kg(-1)) given to each patient, the level of sensory block and complications were recorded. RESULTS: The level of sensory block was higher in Group II (T7) than Group I (T9) (P < 0.01). The doses of midazolam were 0.063 mg kg(-1) in Group I, 0.065 mg kg(-1) in Group II and 0.101 mg kg(-1) in Group III (P < 0.001). There was no correlation between level of sensory block and dose of midazolam in Group I (r = -0.293, P = 0.21) and Group II (r = 0.204, P = 0.39). CONCLUSIONS: Different doses of hyperbaric bupivacaine for spinal anaesthesia do not affect the midazolam requirements for sedation. However, spinal anaesthesia with hyperbaric bupivacaine with a maximum spread in the middle thoracic dermatomes may be associated with sedative effects and thus a reduced need for further sedation with midazolam.
Subject(s)
Anesthesia, Spinal , Anesthetics, Local/administration & dosage , Bupivacaine/administration & dosage , Hypnotics and Sedatives/administration & dosage , Midazolam/administration & dosage , Adult , Anesthesia, General , Double-Blind Method , Female , Humans , MaleABSTRACT
BACKGROUND AND OBJECTIVE: The aim of the study was to report our experience concerning the effectiveness, complications and safety of spinal anaesthesia, and to determine whether spinal anaesthesia was effective in full-term infants undergoing elective inguinal hernia repair. METHODS: Sixty-eight full-term infants aged < 6 months were included in the study. Infants were divided into three groups; Group I (< 1 month, n = 20), Group II (> 1 and < 3 months, n = 26), and Group III (3-6 months, n = 22). All spinal blocks were performed under mask inhalation anaesthesia. A dose of bupivacaine 0.5% 0.5 mg kg(-1) was used for infants under 5kg and 0.4 mg kg(-1) for those over 5 kg. Heart rate, mean arterial pressure, respiratory rate and SPO2 were recorded before and after spinal anaesthesia at 5 min intervals. Time to onset of analgesia, time to start of operation, duration of operation, anaesthesia and hospitalization, postoperative analgesic requirement and complications were recorded. RESULTS: Adequate spinal anaesthesia without sedation was better, time to obtain maximum cutaneous analgesia was shorter and need for sedation and postoperative analgesic requirement were significantly lower in Group I. Although heart rate, mean arterial pressure and respiratory rate decreased < 20% in all groups following spinal analgesia, the decrease in Group I was lower than the others. CONCLUSIONS: Spinal anaesthesia is an effective choice in inguinal hernia repair for full-term infants aged < 1 month, providing excellent and reliable surgical conditions. However, this technique is not as useful for infants aged between 1 and 6 months.
