Effects of Intravenous Magnesium Sulfate on the Prevention of Pain Following Injection of Microemulsion Propofol

OBJECTIVE: The aim of this study was to investigate the effects of intravenous magnesium sulfate on the prevention of pain during the injection of microemulsion propofol. Magnesium is a known calcium channel blocker and a physiological N-methyl-D-aspartate receptor antagonist. METHODS: American Society of Anesthesiologists I and II adults (n=114) undergoing general anesthesia for surgery were randomly assigned into two groups (n=57 per group). This study was designed in prospective and double-blind manner. Patients in the LM group (n=57) received pretreatment with 2% lidocaine (40 mg) and magnesium sulfate 10 mg/kg, while patients in group L (n=57) received pretreatment with 2% lidocaine (40 mg) and normal saline (2 mL) accompanied by venous occlusion. Induction with microemulsion propofol (Aquafol) 2 mg/kg was accomplished following the release of venous occlusion. Pain intensity was assessed on a four-point scale according to patient movement (grade 0, no movement; grade 1, movement in wrist only; grade 2, movement in the upper arm & shoulder of injected arm; grade 3, generalized movement). Systolic blood pressure, diastolic blood pressure, and heart rate were evaluated. RESULTS: A significant difference in pain intensity following injection of microemulsion propofol between the groups was found (P<0.05). In addition, the incidence of hypertension after injection was lower in the LM group than in the L group (P<0.05). CONCLUSION: The combination of magnesium and lidocaine are effective in attenuating the pain induced by microemulsion propofol injection when compared with lidocaine alone.

Suspected Anaphylactic Reaction Associated with Microemulsion Propofol during Anesthesia Induction

Although rare, intraoperative anaphylaxis can lead to significant morbidity and mortality. Aquafol(R) (Daewon Pharmaceutical Co. Ltd., Seoul, Korea), a microemulsion propofol, was developed to eliminate lipid solvent-related adverse events, and was used in clinical anesthesia since 2009 with little data about severe side effects such as anaphylaxis. A healthy 16-yr-old male patient who had past medical history with two previous operations of no complications developed cardiovascular shock with generalized erythema following administration of microemulsion propofol during anesthesia induction. Intravenous injection of epinephrine and steroid rescued him. He remained in a stable state without any problems postoperatively and was discharged. Clinicians should consider this rare but serious complication during induction of anesthesia with propofol.

Lipid-Emulsion Propofol Less Attenuates the Regulation of Body Temperature than Micro-Emulsion Propofol or Sevoflurane in the Elderly

PURPOSE: Anesthesia and surgery commonly cause hypothermia, and this caused by a combination of anesthetic-induced impairment of thermoregulatory control, a cold operation room environment and other factors that promote heat loss. All the general anesthetics markedly impair normal autonomic thermoregulatory control. The aim of this study is to evaluate the effect of two different types of propofol versus inhalation anesthetic on the body temperature. MATERIALS AND METHODS: In this randomized controlled study, 36 patients scheduled for elective laparoscopic gastrectomy were allocated into three groups; group S (sevoflurane, n=12), group L (lipid-emulsion propofol, n=12) and group M (micro-emulsion propofol, n=12). Anesthesia was maintained with typical doses of the study drugs and all the groups received continuous remifentanil infusion. The body temperature was continuously monitored after the induction of general anesthesia until the end of surgery. RESULTS: The body temperature was decreased in all the groups. The temperature gradient of each group (group S, group L and group M) at 180 minutes from induction of anesthesia was 2.5+/-0.6degrees C, 1.6+/-0.5degrees C and 2.3+/-0.6degrees C, respectively. The body temperature of group L was significantly higher than that of group S and group M at 30 minutes and 75 minute after induction of anesthesia, respectively. There were no temperature differences between group S and group M. CONCLUSION: The body temperature is maintained at a higher level in elderly patients anesthetized with lipid-emulsion propofol.