Jin-Young Hwang

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.

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.

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.

Comparison of propofol and the combination of propofol and alfentanil during bronchoscopy: a randomized study

Background: Propofol is an excellent sedative agent for use in patients undergoing bronchoscopy. The addition of an opioid to propofol can be advantageous because of the antitussive effect of the opioid and the possible improvement in sedation quality. However, it may increase the risk of hypoxaemia. To investigate the effect of the addition of alfentanil to propofol, we performed a prospective study to compare propofol‐only sedation with propofol–alfentanil combination sedation in patients undergoing bronchoscopy.

Effect of Scalp Blocks with Levobupivacaine on Recovery Profiles After Craniotomy for Aneurysm Clipping: A Randomized, Double-Blind, and Controlled Study

OBJECTIVE This study was conducted to evaluate the effect of scalp blocks using levobupivacaine on recovery profiles including postoperative pain, patient-controlled analgesia (PCA) consumption, postoperative nausea and vomiting (PONV), and other adverse events in patients undergoing frontoparietal craniotomy for aneurysm clipping. METHODS Fifty-two patients scheduled for elective frontoparietal craniotomy for unruptured aneurysm clipping were enrolled. After surgery, scalp blocks were performed using normal saline (group C, n = 26) or 0.75% levobupivacaine (group L, n = 26). Postoperative pain scores and PCA consumption were recorded for 72 hours after recovery of consciousness. The time from patient recovery to the first use of PCA drug and rescue analgesics, the requirement for vasoactive agents, and adverse effects related to PCA and local anesthetics also were recorded. RESULTS Postoperative pain scores and PCA consumption in group L were lower than in group C (P < .05). The time intervals from patient recovery to the first use of PCA drug (P < .001) and rescue analgesics (P = .038) was longer in group L than in group C. Additionally, less antihypertensive agent was required (P = .017), and PONV occurred less frequently (P = .039) in group L than in group C. CONCLUSIONS Scalp blocks with 0.75% levobupivacaine improved recovery profiles in that it effectively lowered postoperative pain and PCA consumption without severe adverse events and also reduced the requirement for a postoperative antihypertensive agent and the incidence of PONV in patients who underwent frontoparietal craniotomy for aneurysm clipping.

Effect of pretreatment with simvastatin on spinal cord ischemia-reperfusion injury in rats.

OBJECTIVE The aim of this study was to evaluate the pretreatment effect of simvastatin on spinal cord ischemia-reperfusion injury. DESIGN Prospective, interventional study. SETTING University research laboratory. PARTICIPANTS Forty-five male Sprague-Dawley rats. INTERVENTIONS Rats were treated with oral simvastatin, 10 mg/kg (simvastatin group; n = 15) or saline (control group; n = 15) for 5 days before ischemia. Spinal cord ischemia was induced using a balloon-tipped catheter placed in the proximal descending aorta in the control and simvastatin groups, but not in the sham group (n = 15). MEASUREMENTS AND MAIN RESULTS Neurologic function was assessed daily using the motor deficit index until 7 days after reperfusion. After the last neurologic evaluation, a histologic examination of the spinal cord was performed. At day 1 after reperfusion, the simvastatin group showed a significantly lower motor deficit index compared with the control group (2.0, 2.0-2.0, v 4.0, 3.5-5.0; p < 0.001). This trend was sustained at day 7 (2.0, 1.5-2.0, v 4.0, 3.0-4.0; p < 0.001). The simvastatin group displayed a significantly larger number of normal motor neurons compared with the control group (mean ± SD, 31.7 ± 6.1 v 20.4 ± 4.4; p < 0.001). However, compared with the sham group, the simvastatin group displayed fewer intact motor neurons (sham group, 38.5 ± 5.1; p = 0.005). CONCLUSIONS Pretreatment with simvastatin, 10 mg/kg, given orally for 5 days before the ischemia-reperfusion insult, improved the neurologic outcome and preserved more normal motor neurons compared with the control group in a rat model of spinal cord ischemia-reperfusion.

The effect of tracheal tube size on air leak around the cuffs

Background This randomized single-blinded, cross-over study was done to evaluate the influence of the size of tracheal tubes on air leaks around the cuffs. Methods In a benchtop model, the number of longitudinal folds on the cuffs was evaluated for different sizes of tracheal tubes. In an anesthetized patient study, thirty patients scheduled for elective surgery under general anesthesia were included. After induction of anesthesia, the trachea was intubated with two sizes of tracheal tubes in a random sequence: in men, internal diameter of 7.5 mm and 8.0 mm; in women, internal diameter of 7.0 mm and 7.5 mm. After tracheal intubation with each tube, air leak pressures were evaluated at intracuff pressures of 20, 25 and 30 cmH2O by auscultation. To calculate the tracheal tube resistance (R), an inspiratory pause of 20% was applied and the resulting peak airway pressure (Ppeak), plateau pressure (Ppl) and mean expiratory tidal volume (Flow) were inserted in the formula R = (Ppeak - Ppl)/Flow. Results More longitudinal folds of the tracheal tube cuffs occurred in larger sized tubes compared to the smaller ones in a benchtop model. Air leakage was significantly less for the smaller tracheal tubes than for the larger ones for each gender at intracuff pressures of 20, 25 and 30 cmH2O. Tracheal tube resistances were not significantly altered by the size of tracheal tube. Conclusions The use of a smaller tracheal tube within an acceptable size can reduce air leakage around the cuff without significantly changing the tracheal tube resistance.

The Effect of Retrograde Autologous Priming of the Cardiopulmonary Bypass Circuit on Cerebral Oxygenation

OBJECTIVE The aim of this study was to investigate the effect of retrograde autologous priming (RAP) of the cardiopulmonary bypass (CPB) circuit on cerebral oxygenation. DESIGN A retrospective cohort study. SETTING A university hospital. PARTICIPANTS Ninety-four patients undergoing CPB. INTERVENTIONS CPB was primed with a RAP technique in the RAP group (n = 46) or with a conventional technique in the control group (n = 48). MEASUREMENT AND MAIN RESULTS Cerebral oxygenation was monitored by measuring the regional cerebral oxygen saturation (rSO(2)). The rSO(2) and Hct values were compared between the groups during surgery. During the CPB period, the RAP group showed significantly higher values for rSO(2) (%) (immediately after the onset of CPB: 51.3 ± 8.4 and 56.3 ± 8.3; 30 minutes after the onset of CPB: 56.3 ± 5.1 and 59.7 ± 7.0; control group and RAP groups, respectively; p < 0.01 for each) and Hct (%) (immediately after the onset of CPB: 21.1 ± 3.7 and 23.1 ± 3.3; 30 minutes after the onset of CPB: 21.9 ± 3.7 and 23.3 ± 2.3; control group and RAP group, respectively; p < 0.02 for each). However, the 2 groups did not differ in rSO(2) (%) (67.2 ± 6.3 and 67.8 ± 6.4) or Hct (%) (27.8 ± 4.1 and 28.9 ± 3.6, control group and RAP group, respectively) at the end of the surgery. CONCLUSIONS The application of RAP to CPB limits the degree of hemodilution and improves cerebral oxygenation during CPB. The present findings suggest a potential benefit of RAP from a neurologic aspect.

Midazolam hypersensitivity during the transportation to theater -A case report-

This report describes a rare case of perioperative midazolam hypersensitivity in a patient without any history of allergy. A 39-year-old man was admitted for endoscopic pansinus surgery. During transportation to the operating room after injecting antibiotic and midazolam intravenously, the patient complained of shortness of breath. At 3 months after the event, an intradermal sensitivity test for midazolam proved positive indicating the incident was caused by midazolam hypersensitivity.

Interrupting gel layer between Double cuffs prevents fluid leakage past tracheal tube cuffs

BACKGROUND Current tracheal tubes (TTs) cannot guarantee a perfect seal against pulmonary aspiration of upper airway secretions. The purpose of this study was to investigate whether a gel layer between the tracheal tube with double cuffs (Double cuffs) prevents fluid leakage past TT cuffs. METHODS In vitro fluid leakage tests were performed using the Double cuff with or without a gel layer between the two cuffs and four commercially available TTs (Euromedical Standard TT, Mallinckrodt Hi-Lo™, Microcuff, and Mallinckrodt TaperGuard™) when placed in artificial tracheas with three-different internal diameters (ID; 16, 20, and 22 mm). Blue-dyed water (5 ml) was placed above the cuff, and the extent of fluid leakage was observed for 48 h. Each test was repeated five times with new tubes at six different intracuff pressures (15, 20, 25, 30, 40, and 50 cm H2O). RESULTS In all of the conventional TTs and the Double cuff without a gel layer, fluid leakage was observed even at clinically acceptable intracuff pressures (25-30 cm H2O). However, in the Double cuff with a gel layer, no fluid leakage was observed for 48 h at all intracuff pressures in three-different sized artificial tracheas. At an intracuff pressure of 20 cm H2O in a 20 mm ID trachea, the average volume of injected gel was 2.0 ml. After removal of the TT, the mean volume of the remaining gel in the trachea was 0.10 ml. CONCLUSIONS A prototype TT with gel-layered Double cuffs completely blocked fluid leakage past the cuffs for 48 h in a bench-top model. Clinical studies are required to determine whether this TT reduces the risk of ventilator-associated pneumonia.