Sang-Hwan Do

Effects of magnesium sulphate on intraoperative anaesthetic requirements and postoperative analgesia in gynaecology patients receiving total intravenous anaesthesia

BACKGROUND This randomized, double-blind, prospective study was undertaken to evaluate the effects of magnesium sulphate on anaesthetic requirements and postoperative analgesia in patients undergoing total i.v. anaesthesia (TIVA). METHODS Fifty patients who underwent gynaecological surgery were randomly divided into two groups. Before induction of anaesthesia, the magnesium group (Group M) received magnesium sulphate 50 mg kg(-1) i.v. as a bolus and then 15 mg kg(-1) h(-1) i.v. by continuous infusion. The control group (Group S) received the same amount of isotonic saline. TIVA (propofol+remifentanil) was administered under bispectral index monitoring during anaesthesia induction and maintenance. Rocuronium was administered before orotracheal intubation and during surgery when the train-of-four count was 2 or more. After operation, patient-controlled analgesia with a solution of ketorolac and morphine was used and the consumption of this solution was recorded. Pain scores at rest and upon movement were evaluated 30 min, 4, 24, and 48 h after surgery. RESULTS Patients in Group M required less rocuronium than those in Group S [mean (SD) 0.44 (0.09) vs 0.35 (0.07) microg kg(-1) min(-1), P<0.05]. The total amounts of propofol and remifentanil administered were similar in the two groups. Postoperative pain scores, cumulative analgesic consumption, and shivering incidents were significantly lower in Group M (P<0.05). Mean arterial pressure just after intubation and during the immediate postoperative period was also significantly lower in Group M (P<0.05). CONCLUSIONS I.v. magnesium sulphate during TIVA reduced rocuronium requirement and improved the quality of postoperative analgesia.

I.V. infusion of magnesium sulphate during spinal anaesthesia improves postoperative analgesia

BACKGROUND In a randomized, double-blind, prospective study, we have evaluated the effect of i.v. infusion of magnesium sulphate during spinal anaesthesia on postoperative analgesia and postoperative analgesic requirements. METHODS Forty patients undergoing total hip replacement arthroplasty under spinal anaesthesia were included. After the induction of spinal anaesthesia, the magnesium group (Group M) received magnesium sulphate 50 mg kg(-1) for 15 min and then 15 mg kg(-1) h(-1) by continuous i.v. infusion until the end of surgery. The saline group (Group S) received the same volume of isotonic saline over the same period. After surgery, a patient-controlled analgesia (PCA) device containing morphine and ketorolac was provided for the patients. Postoperative pain scores, PCA consumption, and the incidences of shivering, postoperative nausea, and vomiting were evaluated immediately after surgery, and at 30 min, 4, 24, and 48 h after surgery. Serum magnesium concentrations were checked before the induction of anaesthesia, immediately after surgery, and at 1 and 24 h after surgery. RESULTS Postoperative pain scores were significantly lower in Group M at 4, 24, and 48 h after surgery (P<0.05). Cumulative postoperative PCA consumptions were also significantly lower in Group M at 4, 24, and 48 h after surgery (P<0.05). Postoperative magnesium concentrations were higher in Group M (P<0.05 at 4, 24, and 48 h after surgery), but no side-effects associated with hypermagnesemia were observed. Haemodynamic variables and the incidences of shivering, nausea, and vomiting were similar in the two groups. CONCLUSIONS I.V. magnesium sulphate administration during spinal anaesthesia improves postoperative analgesia.

Controlled hypotension for middle ear surgery: a comparison between remifentanil and magnesium sulphate

BACKGROUND This prospective, randomized study was designed to compare remifentanil and magnesium sulphate during middle ear surgery in terms of postoperative pain and other complications. METHODS Eighty patients undergoing middle ear surgery were enrolled in the study. Patients were randomized into two groups of 40 to receive remifentanil (Group R) or magnesium sulphate (Group M) infusion. Propofol 2 mg kg(-1) was administered to induce anaesthesia, which was maintained using sevoflurane. Group R received a continuous infusion of remifentanil titrated between 3 and 4 ng ml(-1) using target-controlled infusion, whereas Group M received an i.v. magnesium sulphate bolus of 50 mg kg(-1) followed by a 15 mg kg(-1) h(-1) continuous infusion to maintain a mean arterial pressure (MAP) between 60 and 70 mm Hg. Haemodynamic variables, surgical conditions, postoperative pain, and adverse effects, such as postoperative nausea and vomiting (PONV) and shivering, were recorded. RESULTS Controlled hypotension was well maintained in both groups. MAP and heart rate were higher in Group R than in Group M after operation. Surgical conditions were not different between the two groups. Postoperative pain scores were significantly lower in Group M than in Group R (P<0.05). Seventeen patients in Group R (43%) and seven patients in Group M (18%) developed PONV (P=0.01). CONCLUSIONS Both magnesium sulphate and remifentanil when combined with sevoflurane provided adequate controlled hypotension and proper surgical conditions for middle ear surgery. However, patients administered magnesium sulphate had a more favourable postoperative course with better analgesia and less shivering and PONV.

Effects of intravenous iron combined with low-dose recombinant human erythropoietin on transfusion requirements in iron-deficient patients undergoing bilateral total knee replacement arthroplasty.

BACKGROUND: The authors examined the impact of parenteral iron and recombinant human erythropoietin‐β (rHuEPO‐β) administered in the bilateral total knee replacement arthroplasty (TKRA), on postoperative anemia and transfusion requirements in iron‐deficient patients.

Prophylactic dexamethasone decreases the incidence of sore throat and hoarseness after tracheal extubation with a double-lumen endobronchial tube.

BACKGROUND:Postoperative sore throat and hoarseness are common complications after tracheal intubation, particularly after using a double-lumen endobronchial tube (DLT). We conducted a prospective, randomized, double-blind, placebo-controlled study to evaluate the efficacy of dexamethasone for reducing the incidence and severity of postoperative sore throat and hoarseness. METHODS:One hundred sixty-six patients (aged 18–75 yr) scheduled for thoracic surgery with a DLT were enrolled. Before induction of general anesthesia, 0.1 mg/kg dexamethasone (Group D1), 0.2 mg/kg dexamethasone (Group D2), or a placebo (Group P) were infused IV in a double-blind and prospectively randomized manner. Glottic exposure as defined by Cormack and Lehane score, resistance to DLT insertion, number of intubation attempts, time to achieve intubation, and the duration of tracheal intubation were recorded. At 1 h and 24 h after tracheal extubation, the patients were evaluated for sore throat and hoarseness using a visual analog scale (VAS; where 0 = no pain and 100 = worst pain imaginable). RESULTS:One hour after tracheal extubation, the incidence of postoperative sore throat and hoarseness, along with the severity of sore throat were lower in Group D1 (31%, P = 0.021; 11%, P = 0.003; and VAS 12.4, P < 0.001, respectively) and D2 (11%, P = 0.001; 4%, P = 0.001; and VAS 6.6, P < 0.001, respectively) compared with Group P (53%, 36% and VAS 30.9, respectively). Twenty-four hours after tracheal extubation, the incidence of postoperative sore throat, hoarseness, and the severity of sore throat were significantly lower in Group D2 (27%, P = 0.002; 15%, P = 0.001; and VAS 29.9, P < 0.002, respectively) compared with Group D1 (47%, 31%, and VAS = 43.9, respectively) and Group P (57%, 45%, and VAS = 51.3, respectively). There was no complication associated with the dexamethasone administration. CONCLUSION:The prophylactic use of 0.2 mg/kg of dexamethasone significantly decreases the incidence and severity of sore throat and hoarseness 1 h and 24 h after tracheal extubation of a DLT.

Emergence agitation in children undergoing adenotonsillectomy: a comparison of sevoflurane vs. sevoflurane-remifentanil administration.

Sevoflurane is widely used in paediatric anaesthesia but frequently causes emergence agitation (EA). This study evaluated whether limiting the sevoflurane concentration by combining remifentanil with sevoflurane reduced the incidence of EA.

Randomized double-blind study of remifentanil and dexmedetomidine for flexible bronchoscopy

BACKGROUND The safety profiles and efficacies of remifentanil and dexmedetomidine (a sedative-analgesic without respiratory depression) for sedation during flexible bronchoscopy were investigated. METHODS Seventy-two patients undergoing elective flexible bronchoscopy were randomly assigned to a propofol-remifentanil group (Group PR, n=36) or a propofol-dexmedetomidine group (Group PD, n=36). The primary outcome was the incidence of oxygen desaturation. Haemodynamic variables, adverse events, need of oral cavity suction, cough scores, satisfaction scores of patients and bronchoscopists, levels of sedation, and recovery times were also compared. RESULTS The incidence of oxygen desaturation was significantly lower in the PD group than in the PR group (P=0.01). There were no significant differences between groups in terms of level of sedation, oxygen saturation, mean arterial pressure, heart rate over time, cough scores, or patient satisfaction scores (P>0.05). However, cough scores and bronchoscopist satisfaction scores (P<0.01) were lower in the PD group. In addition, topical anaesthesia (P<0.01) was required more frequently and recovery time (P=0.00) was significantly longer in the PD group. However, oral suction (P=0.03) was required less frequently in the PD group. CONCLUSIONS Dexmedetomidine was associated with fewer incidents of oxygen desaturation and a reduced need for oral cavity suction than remifentanil during flexible bronchoscopy. However, dexmedetomidine was associated with a longer recovery time and poorer bronchoscopist satisfaction score.

The Influence of Head and Neck Position on the Oropharyngeal Leak Pressure and Cuff Position of Three Supraglottic Airway Devices

BACKGROUND: With supraglottic airway devices, such as the laryngeal tube suction (LTS), ProSeal laryngeal mask airway (PLMA) and Cobra perilaryngeal airway (CobraPLA), oropharyngeal leak pressure or cuff position may vary according to changes in the position of the head and neck. We evaluated oropharyngeal leak pressure and cuff pressure of the PLMA, LTS, and CobraPLA in different head and neck positions. METHODS: One-hundred-thirty-nine patients (aged 18-70 yr) scheduled for minor surgical procedures were randomly allocated to one of the supraglottic airway devices. Oropharyngeal leak pressure and cuff pressure were evaluated in four head and neck positions: neutral, 45° of flexion, 45° of extension, and 45° of right rotation. Adverse events (i.e., difficulty in ventilation or gastric insufflation) were assessed during the study. RESULTS: Leak pressures of the PLMA were lowest in the extension (18.5 vs 23.9 and 26.8 cm H2O of LTS and CobraPLA, respectively; P < 0.001) and in the rotation position (25.0 vs 29.4 and 28.5 cm H2O of LTS and CobraPLA, respectively; P < 0.005). With the CobraPLA, gastric insufflations occurred before the oropharyngeal leak in 37 of 45 patients. There were ventilatory difficulties in seven patients with LTS after neck flexion, which required tracheal intubation. CONCLUSIONS: The PLMA showed significantly lower oropharyngeal leak pressures than did the LTS or CobraPLA in the neck extension and rotation positions. Caution is warranted when changing the position of the head and neck when using the Cobra-PLA or LTS as gastric insufflation or ventilatory difficulty may occur.

Analgesia before a spinal block for femoral neck fracture: fascia iliaca compartment block

Background: In this prospective randomized study, the authors compared the analgesic effect of a fascia iliaca compartment (FIC) block with that of intravenous (i.v.) alfentanil when administered to facilitate positioning for spinal anaesthesia in elderly patients undergoing surgery for a femoral neck fracture.

Effects of magnesium sulphate on intraoperative neuromuscular blocking agent requirements and postoperative analgesia in children with cerebral palsy

BACKGROUND In this double-blind, randomized, placebo-controlled study, we evaluated the effects of magnesium sulphate on neuromuscular blocking agent requirements and analgesia in children with cerebral palsy (CP). METHODS We randomly divided 61 children with CP undergoing orthopaedic surgery into two groups. The magnesium group (Group M) received magnesium sulphate 50 mg kg(-1) i.v. as a bolus and 15 mg kg(-1) h(-1) by continuous infusion during the operation. The control group (Group S) received the same amount of isotonic saline. Rocuronium was administered 0.6 mg kg(-1) before intubation and 0.1 mg kg(-1) additionally when train-of-four counts were 2 or more. I.V. fentanyl and ketorolac were used to control postoperative pain. Total infused analgesic volumes and pain scores were evaluated at postoperative 30 min, and at 6, 24, and 48 h. RESULTS The rocuronium requirement of Group M was significantly less than that of Group S [0.29 (0.12) vs 0.42 (0.16) mg kg(-1) h(-1), P<0.05]. Cumulative analgesic consumption in Group M was significantly less after operation at 24 and 48 h (P<0.05), and pain scores in Group M were lower than in Group S during the entire postoperative period (P<0.05). Serum magnesium concentrations in Group M were higher until 24 h after operation (P<0.05). The incidence of postoperative nausea and vomiting and rescue drug injections was similar in the two groups. No shivering or adverse effects related to hypermagnesaemia were encountered. CONCLUSIONS I.V. magnesium sulphate reduces rocuronium requirements and postoperative analgesic consumption in children with CP.