The Local Anesthetic Effect of 10% Lidocaine Spray on the Larynx / 대한마취과학회지

BACKGROUND: Although topically applied laryngeal lidocaine is known to be effective in preventing the cardiovascular events associated with endotracheal intubation, it is still debated whether the mechanism of action of topically applied laryngeal lidocaine is via increased plasma concentration of lidocaine or via topically induced superficial anesthesia. The purpose of the present study is to observe vocal cord responses to stimulation and to find out whether topically induced superficial anesthesia with 10% lidocaine spray is effective under propofol anesthesia. METHODS: Twenty-four patients scheduled for operation on the upper or lower extremities were randomly allocated to two groups: (1) twelve patients who did not receive 10% lidocaine spray before the insertion of a laryngeal mask airway (LMA), (2) twelve patients who received 10% lidocaine spray before the insertion of LMA. The vocal cords of each patient were stimulated by the spraying of 0.2 ml distilled water or directly by bronchoscope tip, and the evoked responses were assessed by analyzing the hemodynamic and respiratory variables and vocal cord movement. The vocal cord movements elicited by the laryngeal stimulation were classified into four grades. RESULTS: There was a significant difference between the groups regarding vocal cord movement (P < 0.05). There were no differences between the groups regarding hemodynamic and respiratory variables. CONCLUSIONS: The result indicates that there is a topical anesthetic effect on the vocal cords by 10% lidocaine spray on the larynx.

Is Muscle Relaxants Necessary during the Anesthesia for Cataract Surgery with LMA? / 대한마취과학회지

BACKGROUND: The recovery of spontaneous ventilation is delayed in elderly patients in whom muscle relaxants has been administered for general anesthesia. We evaluated the appropriateness of microscopic cataract surgery without using muscle relaxants in elderly patients. METHODS: Forty two ASA physical status I and II patients for cataract surgery were randomly assigned to two groups. Glycopyrrolate 0.2 mg, fentanyl 2 mcg/kg and propofol 2 mg/kg were administered intravenously followed by vecuronium 1 mg/kg iv in group I and 10% lidocaine 1.5 mg/kg spray into oropharynx in group II. Laryngeal mask (LMA) was inserted for airway management and anesthesia was maintained by only propofol infusion in both groups. Whether the patient moved during the surgery, whether ephedrine was administered and the propofol infusion rate were recorded. RESULTS: Six patients of group I and 1 patient of group II were moved during surgery. Only in group II, 7 patients received intravenously ephedrine administration. Mean infusion rate of propofol was 0.114 mg/kg/min in group I and 0.159 mg/kg/min in group II. CONCLUSION: In general anesthesia for microscopic cataract surgery, the combination of fentanyl 2 mcg/kg, propofol 2 mg/kg and infusion, 10% lidocaine spray and laryngeal mask without muscle relaxants is a good alternate method of keeping airway.

Is Muscle Relaxants Necessary during the Anesthesia for Cataract Surgery with LMA? / 대한마취과학회지

BACKGROUND: The recovery of spontaneous ventilation is delayed in elderly patients in whom muscle relaxants has been administered for general anesthesia. We evaluated the appropriateness of microscopic cataract surgery without using muscle relaxants in elderly patients. METHODS: Forty two ASA physical status I and II patients for cataract surgery were randomly assigned to two groups. Glycopyrrolate 0.2 mg, fentanyl 2 mcg/kg and propofol 2 mg/kg were administered intravenously followed by vecuronium 1 mg/kg iv in group I and 10% lidocaine 1.5 mg/kg spray into oropharynx in group II. Laryngeal mask (LMA) was inserted for airway management and anesthesia was maintained by only propofol infusion in both groups. Whether the patient moved during the surgery, whether ephedrine was administered and the propofol infusion rate were recorded. RESULTS: Six patients of group I and 1 patient of group II were moved during surgery. Only in group II, 7 patients received intravenously ephedrine administration. Mean infusion rate of propofol was 0.114 mg/kg/min in group I and 0.159 mg/kg/min in group II. CONCLUSION: In general anesthesia for microscopic cataract surgery, the combination of fentanyl 2 mcg/kg, propofol 2 mg/kg and infusion, 10% lidocaine spray and laryngeal mask without muscle relaxants is a good alternate method of keeping airway.

Minimum Effective Anesthetic Concentration of Hyperbaric Tetracaine 10 mg for Spinal Anesthesia / 대한마취과학회지

BACKGROUND: Minimum effective anesthetic concentration (MEAC) of local anesthetics for spinal anesthesia, defined as the concentration at which a spinal anesthetic agent produces surgical anesthesia within 20 minutes of administration in 50% of patients. This concept is similar to the concept of minimum alveolar concentration (MAC) for inhalation anesthetic. Furthermore, as MEAC may vary with the administered dose, it will be determined using 10 mg of hyperbaric tetracaine. METHODS: 10 mg hyperbaric tetracaine containing dextrose 10 % was administered intrathecally to 12 patients (ASA I-II, age 20~40 yr), who were undergoing lower limb or urological procedures within 90 minutes, at concentrations ranging from 0.07~0.1%. The choice of tetracaine concentration was determined by Dixon's up-and-down method. Complete anesthesia was defined as: (1) pinprick anesthesia at or higher than T10 and (2) complete leg paralysis; all occurring in both lower extremities within 20 min. General anesthesia was initiated if spinal anesthesia was incomplete. RESULTS: MEAC of 10 mg hyperbaric tetracaine was 0.083 %. Mean anesthetic duration was 75.2 minutes (range: 40~100 min). The maximum sensory block level ranged from T3~T8. CONCLUSION: The aim of this study was to establish new concept of minimum effective anesthetic concentration of hyperbaric tetracaine for spinal anesthesia. We recognized that spinal anesthesia can be accomplished with very dilute solution. As fixed dose, no correlation was found between concentration of the spinal tetracaine solution with the highest sensory level, anesthetic duration and the degree of mean arterial pressure decreased.

Minimum Effective Anesthetic Concentration of Hyperbaric Tetracaine 10 mg for Spinal Anesthesia / 대한마취과학회지

BACKGROUND: Minimum effective anesthetic concentration (MEAC) of local anesthetics for spinal anesthesia, defined as the concentration at which a spinal anesthetic agent produces surgical anesthesia within 20 minutes of administration in 50% of patients. This concept is similar to the concept of minimum alveolar concentration (MAC) for inhalation anesthetic. Furthermore, as MEAC may vary with the administered dose, it will be determined using 10 mg of hyperbaric tetracaine. METHODS: 10 mg hyperbaric tetracaine containing dextrose 10 % was administered intrathecally to 12 patients (ASA I-II, age 20~40 yr), who were undergoing lower limb or urological procedures within 90 minutes, at concentrations ranging from 0.07~0.1%. The choice of tetracaine concentration was determined by Dixon's up-and-down method. Complete anesthesia was defined as: (1) pinprick anesthesia at or higher than T10 and (2) complete leg paralysis; all occurring in both lower extremities within 20 min. General anesthesia was initiated if spinal anesthesia was incomplete. RESULTS: MEAC of 10 mg hyperbaric tetracaine was 0.083 %. Mean anesthetic duration was 75.2 minutes (range: 40~100 min). The maximum sensory block level ranged from T3~T8. CONCLUSION: The aim of this study was to establish new concept of minimum effective anesthetic concentration of hyperbaric tetracaine for spinal anesthesia. We recognized that spinal anesthesia can be accomplished with very dilute solution. As fixed dose, no correlation was found between concentration of the spinal tetracaine solution with the highest sensory level, anesthetic duration and the degree of mean arterial pressure decreased.

Effect of Tramadol in the Teatment of Postanesthetic Shivering / 대한마취과학회지

BACKGROUND: Tramadol is a centrally acting analgesic with weak opioid agonist properties and has effect on the spinal inhibition of pain. This study was designed to evaluate the efficacy of tramadol in the treatment of postanesthetic shivering. METHODS: Sixty patients (ASA class I/II) who showed postanesthetic shivering were randomly assigned into three groups (n=20): Normal saline group; normal saline 10 ml, tramadol (TRD) 0.5 mg/kg group; tramadol 0.5 mg/kg, TRD 1.0 mg/kg group; tramadol 1.0 mg/kg. And all patients received standard postoperative management in the recovery room. Evaluation of the grade of shivering was done at 30 seconds, 2, 5 and 10 minutes from the beginning of the treatment by the same investigator who had injected the drug. The age, sex, weight, duration of anesthesia and axillary temperature were recorded. RESULTS: By 30 seconds, 2 minutes, 5 minutes, and 10 minutes, 0, 4, 9, 9 patients of the 0.5 mg/kg tramadol group (n=20) and 7, 18, 19, 19 patients of the 1.0 mg/kg tramadol group (n=20) stopped the shivering respectively. But in 3 patients of 0.5 mg/kg tramadol group who stopped shivering by 5 minutes, shivering was recurred within 10 minutes and in 3 patients who had not stopped shivering by 5 minutes, shivering stopped by 10 minutes. In the placebo group, only 1 patient stopped shivering by 5 minutes. CONCLUSION: 1.0 mg/kg of tramadol was effective for the treatment of postanesthetic shivering but 0.5 mg/kg of tramadol was ineffective.

Effect of Tramadol in the Teatment of Postanesthetic Shivering / 대한마취과학회지

BACKGROUND: Tramadol is a centrally acting analgesic with weak opioid agonist properties and has effect on the spinal inhibition of pain. This study was designed to evaluate the efficacy of tramadol in the treatment of postanesthetic shivering. METHODS: Sixty patients (ASA class I/II) who showed postanesthetic shivering were randomly assigned into three groups (n=20): Normal saline group; normal saline 10 ml, tramadol (TRD) 0.5 mg/kg group; tramadol 0.5 mg/kg, TRD 1.0 mg/kg group; tramadol 1.0 mg/kg. And all patients received standard postoperative management in the recovery room. Evaluation of the grade of shivering was done at 30 seconds, 2, 5 and 10 minutes from the beginning of the treatment by the same investigator who had injected the drug. The age, sex, weight, duration of anesthesia and axillary temperature were recorded. RESULTS: By 30 seconds, 2 minutes, 5 minutes, and 10 minutes, 0, 4, 9, 9 patients of the 0.5 mg/kg tramadol group (n=20) and 7, 18, 19, 19 patients of the 1.0 mg/kg tramadol group (n=20) stopped the shivering respectively. But in 3 patients of 0.5 mg/kg tramadol group who stopped shivering by 5 minutes, shivering was recurred within 10 minutes and in 3 patients who had not stopped shivering by 5 minutes, shivering stopped by 10 minutes. In the placebo group, only 1 patient stopped shivering by 5 minutes. CONCLUSION: 1.0 mg/kg of tramadol was effective for the treatment of postanesthetic shivering but 0.5 mg/kg of tramadol was ineffective.

Anesthesia for Cesarean Section with HELLP Syndrome: A case report / 대한마취과학회지

Hemolysis, elevated liver enzymes and low platelets (HELLP) syndrome is a variant presentation of severe preeclampsia/eclampsia. A 24-year old woman presented herself at 34 wk of pregnancy. Based on the clinical and laboratory assessment, HELLP syndrome was diagnosed. Cesarean section was performed under general anesthesia without invasive monitoring due to stable blood pressure. The course of anesthesia and surgery was uneventful and she delivered female neonate weighing 1770 gram. After the operation, the patient was transferred to the intensive care unit immediately. During the intensive care bleeding started and signs of disseminated intravascular coagulopathy showed up. Any improvement was not made after transfusion and every other supportive therapy. By the request of guardian, she was transferred to tertiary hospital, where she died.

ED95 of Esmolol for Protection of Tachycardia and Systolic Hypertension by Endotracheal Intubation in Anesthetic Induction with Enflurane, Nitrous Oxide, Thiopental and Fentanyl / 대한마취과학회지

BACKGROUND: Esmolol has been used combined with small dose of fentanyl to prevent tachycardia and hypertension induced by tracheal intubation, but there has been few studies about the appropriate doses of esmolol when used combined with fentanyl. METHODS: According to esmolol dose, 140 patients were randomly allocated to 7 groups of 20 patients. After 2 microgram/kg of fentanyl, 4 mg/kg of thiopental and 0.12 mg/kg of vecuronium were intravenously administered, mask ventilation for 3 minutes with enflurane, nitrous oxide and oxygen was followed. Then one of the doses of esmolol, 0, 0.2, 0.3, 0.45, 0.6, 0.8 or 1.0 mg/kg was administered. Ninty seconds later, tracheal intubation by direct laryngoscopy was performed. After then heart rate was monitored continuously and blood pressure was measured 5 times with 1 minute interval. The highest heart rate and systolic blood pressure were recorded. We calculated the doses of esmolol which reduce the incidence of tachycardia (increased above 100 bpm or by more than 40% of preinduction level) and systolic hypertension (increased above 170 mmHg or by more than 40% of preinduction level) below 5% respectively. RESULTS: The ED95 of esmolol for prevention of tachycardia induced by tracheal intubation was 0.56 mg/kg (95% CI: 0.44-0.81 mg/kg). But the incidence of systolic hypertension was so low even without esmolol injection that the esmolol dose was not significant factor. CONCLUSIONS: In anesthetic induction and tracheal intubation with enflurane, nitrous oxide, thiopental, vecuronium, and fentanyl 2 microgram/kg, esmolol 0.56 mg/kg was ED95 of preventing tachycardia. But the incidence of systolic hypertension was acceptably low even without esmolol injection.