Si Young Ok

Prevention of pain with the injection of microemulsion propofol: a comparison of a combination of lidocaine and ketamine with lidocaine or ketamine alone

Background Aquafol, a microemulsion propofol, causes more severe and frequent pain on injection than propofol. The purpose of this study was to compare a combination of lidocaine and ketamine on aquafol-induced pain with lidocaine or ketamine alone during the induction of anesthesia. Methods In this prospective, randomized, double-blinded study, 130 healthy patients who were undergoing elective surgery under general anesthesia were enrolled. The patients received IV lidocaine 40 mg plus ketamine 25 mg (Group LK, n = 43), lidocaine 40 mg (Group L, n = 42), or ketamine 25 mg (Group K, n = 45) with a rubber tourniquet on the forearm 1 min before the injection of microemulsion propofol. The pain score was assessed by a 4-point verbal rating scale (VRS) at 10 seconds after injection of microemulsion propofol 30 mg and during the injection of the remaining total dose. Results The incidence and severity of pain was significantly lower in Group LK than Group L or Group K at 10 seconds after the injection of microemulsion propofol 30 mg (P < 0.05). And the incidence and severity of pain was significantly lower in Group LK and Group K than Group L during the injection of the remaining total dose (P < 0.05). Conclusions Pretreatment with IV lidocaine 40 mg plus ketamine 25 mg with a rubber tourniquet on the forearm 1 min before the injection of microemulsion propofol is more effective than lidocaine 40 mg or ketamine 25 mg alone in preventing pain from the injection of microemulsion propofol.

Changes in the relationship between the right internal jugular vein and an anatomical landmark after head rotation

Background This study was performed to ultrasonographically demonstrate the changes in relationship between the right internal jugular vein (IJV) and an anatomical landmark in two different head positions: neutral and rotated. Methods This was a randomized clinical trial. One hundred patients scheduled for elective surgery under general anesthesia with endotracheal intubation were enrolled in this study. The patients were placed in the supine position with a neutral head position and without a pillow. The apex of the triangle formed by the sternal and clavicular heads of the sternocleidomastoid muscle and clavicle was marked (AL point : anatomical landmark point). Ultrasonography of the neck anatomy was performed and the skin was marked at the central point of the IJV (US point: ultrasonography point). The other investigator measured the distance from the AL point to the US point (AL-US distance). The patients head was then turned 30° to the left; the same procedure was repeated and the AL-US distance was again measured. The changes in AL-US distance were calculated. Results The AL-US distance increased significantly after 30° head rotation compared with that in a head neutral position. The mean ± SD of the AL-US distance was 0.28 ± 0.78 cm in the neutral head position and 0.83 ± 1.03 cm in the head rotated position. Conclusions The anatomical landmark point becomes more distant from the actual right IJV point and moves more medially after head rotation. We suggest minimizing the angle of head rotation and taking this distance into consideration when using the landmark-guided method.

The effect of intravenous low dose ketamine for reducing postoperative sore throat

Background This study was performed to evaluate the effectiveness of intravenous low dose ketamine for reducing the incidence and severity of postoperative sore throat (POST). Methods This was a prospective, randomized, double-blind clinical trial. The study population consisted of 70 patients between 20 and 70 years old who were classified as American Society of Anesthesiologists I-II and were scheduled for elective laparoscopic cholecystectomy. The patients were divided randomly into two groups. Patients in the ketamine group received an intravenous injection of 0.5 mg/kg of ketamine just before induction, followed by 10 µg/kg/min throughout the operation. Patients in the control group received intravenous saline instead of ketamine. The patients were interviewed 1, 6, and 24 h after the operation. The incidence and severity of POST were recorded. Results No significant differences in the incidence and severity of POST during the 24 h after the operation were found between the two groups (21/31 in the ketamine group vs. 26/34 in the control group, P = 0.398). Conclusions Intravenous injection of low dose ketamine was not effective for reducing POST.

The hemodynamic changes by different end-tidal CO2 under anesthesia using sevoflurane-N2O

BACKGROUNDnHypercapnia augments cardiac output and can initiate a sympathetically mediated release of catecholamines to increase cardiac output. Many studies of hemodynamic changes by hypercapnia under general anesthesia with inhalation anesthetics besides sevoflurane. This study examined the hemodynamic changes by increasing end-tidal carbon dioxide (EtCO2) under sevoflurane-N2O anesthesia.nnnMETHODSnTwenty patients were enrolled in the study. We studied stable, mechanically ventilated patients under general anesthesia maintained with O2 2 L/min - N2O 2 L/min - sevoflurane (1.5-2.5 vol%). Hypercapnia were obtained by reducing tidal volume and respiratory rate. EtCO2 was adjusted to 30, 40, 50 mmHg with each concentration maintained for 15 min. Global hemodynamic variables were monitored with a pulmonary artery catheter.nnnRESULTSnThere were no changes in mean arterial pressure or heart rate by hypercapnia. Acute moderate hypercapnia increased cardiac output (4.9 +/- 1.7, 5.5 +/- 1.7, 6.2 +/- 2.1 L/min; P < 0.05), cardiac index (3.0 +/- 0.9, 3.4 +/- 0.9, 3.8 +/- 1.1 L/min/m2; P < 0.05), pulmonary artery pressure (16.9 +/- 3.7, 19.6 +/- 4.2, 23.0 +/- 4.7 mmHg), but did not decrease systemic vascular resistance (1,558.3 +/- 500.4, 1,423.5 +/- 678.6, 1,156.8 +/- 374.0 dynes.sec/cm5; P > 0.05).nnnCONCLUSIONSnWhen we changed patient EtCO2 to 30, 40, and 50 mmHg, there were no changes in mean arterial blood pressure and heart rate, but systemic vascular resistance decreased, and cardiac output, cardiac index and mean pulmonary arterial pressure increased significantly.