An analysis of correlation between remifentanil effect site concentration and age blunting hemodynamic response to endotracheal intubation

BACKGROUND: There are many studies using propofol-remifentanil target controlled infusion (TCI) for the prevention of adverse hemodynamic changes during tracheal intubation. Most of these studies suggested optimal remifentanil target concentration without considering age. The purpose of this study is to analyze the correlation between concentration of remifentanil and age to blunting adverse hemodynamic responses during tracheal intubation. METHODS: We enrolled ASA physical state I or II 55 patients, aged 12-75 years undergoing elective surgery. Anesthesia was induced using a propofol TCI (Marsh model). A 4micro/ml effect-site concentration of propofol was chosen. Rocuronium 0.6 mg/kg was administered after the patients lost consciousness. Remifentanil TCI (Minto model) was started 1 minute after the propofol injection. Initially, a 3 ng/ml effect-site concentration was chosen. The next concentration was chosen using Dixon's up-and-down method. The non-invasive blood pressure and heart rate were recorded before induction (baseline), after the remifentanil infusion, immediately after intubation as well as 1 and 3 minutes after intubation. RESULTS: Probit analysis revealed a remifentanil effect site EC50 and EC95 in all patients to be 1.768 ng/ml (S.E. +/-0.136) and 2.912 ng/ml (S.E. +/-0.307). Final probit equation was as following consisted with age and remifentanil effect site concentration. Probit = -2.588 + 1.886 remifentanil effect site concentration -0.022 x Age. CONCLUSIONS: The probability of success rate of blunting adverse hemodynamic response is related to the concentration of remifentanil directly and age inversely.

Effect of Clonidine Supplementation on Jugular Bulb Oxygen Saturation and Carbon Dioxide Reactivity during Desflurane Anesthesia / 대한마취과학회지

BACKGROUND: The alpha2-agonist clonidine is an adjunct in general anesthesia. Clonidine constricts cerebral arteries and decreases cerebral blood flow (CBF), but does not alter cerebral metabolic rate (CMR). Thus cerebral ischemia is possible due to CBF/CMR imbalance. This study was designed to prove the effects of clonidine bolus up on CBF and CO2 reactivity in desflurane anesthesia. METHODS: Thirty patients were divided into a clonidine group (n = 15) and a control group (n = 15). Anesthesia was induced with thiopental and pancuronium, and maintained with 50% N2O/O2/ Desflurane. The jugular bulb was cannulated to measure jugular bulb oxygen saturation (SjO2). MAP and SjO2 were measured after induction, after clonidine (2 microgram/kg) or normal saline administration and during hyperventilation. RESULTS: After clonidine administration, MAP decreased from 95.7+/-9.8 mmHg to 81.1+/-6.3 mmHg and was 79.9+/-5.0 mmHg during hyperventilation. In the control group, the corresponding MAP values 95.7+/-9.8 mmHg, 81.1+/-6.3 mmHg and 79.9+/-5.0 mmHg. After clonidine administration, SjO2 was decreased from 84.7+/-3.7% to 81.1+/-5.2%, and was 71.5+/-8.4% during hyperventilation (P = 0.003, P = 0.000) and in control group, there were 95.7+/-9.8%, 81.1+/-6.3% and 79.9+/-5.0%, respectively. CO2 reactivity was expressed as a change of SjO2 per unit change of PaCO2, 1.15+/-1.19%/mmHg versus 1.43+/-0.98%/mmHg (P = 0.49). CONCLUSIONS: During desflurane anesthesia, clonidine-induced constriction of the cerebral arteries was demonstrated but CO2 reactivity was well preserved.

Difference of Jugular Bulb Oxygen Saturation under Propofol, Enflurane and Isoflurane Anesthesia with Hydralazine-induced Deliberate Hypotension / 대한마취과학회지

BACKGROUND: Hydralazine produces cerebral vasodilation, which could appear differently according to which kind of anesthetics was used. SjO2, CBF and AJDO2 have been studied during general anesthesia with enflurane, isoflurane or propofol in 42 patients undergoing spinal surgery. METHODS: Forty-two healthy adult patients were divided into Group P (Propofol-N2O, n = 15), Group E (Enflurane-N2O, n = 15) and Group I (Isoflurane-N2O, n = 12). During the course of the study, the anesthetic concentration was constant. Induced hypotension was provided with hydralazine 20 mg in combination with a continuous infusion of esmolol within 50 - 100ng/kg/min. Arterial blood and jugular bulb blood were obtained and analyzed at normotensive and hypotensive period, respectively. SjO2, was compared within and between groups. RESULTS: SjO2 values of Group P were 66.2 +/- 7.7%, and 81.5 +/- 6.1%, those of Group E were 79.5 +/- 5.6%, and 78.9 +/- 4.9% and those of Group I were 82.0 +/- 6.2%, and 84.4 +/- 3.7% at normotension and hypotension, respectively (P < 0.05 between Group P and Group E, P < 0.05 between Group P and Group I, P < 0.05 within Group P). CONCLUSIONS: When the changes of CBF is assumed with that of SjO2, it may be concluded that CBF increased with hydralazine-induced hypotension in propofol-N2O anesthesia. It may be suggested that hydralazine reverses propofol induced cerebral vasoconstriction.

Thoracodorsal Artery as an Alternative in Complete Arterial Coronary Revascularization: 3 Cases / 대한흉부외과학회지

It is now widely accepted that the complete arterial coronary revascularization has better short and long term results compared to coronary bypass surgery using arterial graft mixed with vein graft mainly due to its superior patency rate. However, sometimes the internal thoracic artery and other conventionally used grafts might be unavailable or it may require caution in using bilateral internal thoracic artery especially in diabetic patient because of the possible risk of the mediastinitis or other associated morbidities. Moreover, there could also be a shortage for arterial graft in case of coronary reoperation. We report our first three cases using thoracodorsal artery(TDA) as an alternative graft in complete arterial coronary revascularization.

The Effect of Clinical Dose Clonidine on the Effect Site Concentration of Propofol to Prevent Patient's Movement during Propofol-N2O Anesthesia / 대한마취과학회지

BACKGROUND: Clonidine has been known to be an alpha2-agonist and may potentiate the anesthetic effect. Clonidine also suppresses hemodynamics, which confounds the indices of anesthetic depth. Thus, the author regarded patient's movement as a standard of anesthetic depth as well as hemodynamic change. Interaction between clonidine and propofol in clinical anesthesia was evaluated when given in clinical dose. METHODS: Forty patients scheduled for spine surgery were randomly assigned into two groups; propofol only (control group, n = 20) and propofol with clonidine (study group, n = 20). In the study group, clonidine was administered intravenously. Anesthesia was inducted with propofol TCI and N2O, and then the effect site concentration of propofol was controlled. The changes of mean arterial pressure, heart rate, and the effect site concentration was observed and analyzed at baseline, before and after skin incision, and then EC50 was obtained and analyzed. RESULTS: Mean arterial pressure and heart rate significantly changed between before and after the skin incision in both groups. There was no significant difference of propofol EC50 in the prevention of patient's movement at the time of skin incision. CONCLUSIONS: The authors concluded that preoperative administration of clinical dose clonidine provides stable hemodynamic conditions in propofol-N2O anesthesia, but no changes in the depth of anesthesia.

Effects of Propofol Used with an Inhalation Anesthetic in the Neuroanesthetic Management on the Jugular Bulb Oxygen Saturation / 대한마취과학회지

BACKGROUND: When we use a volatile anesthetic that increases cerebral blood flow (CBF) and propofol which decreases CBF in appropriate doses, respectively, an increase in ICP and cerebral ischemia can be prevented. The purpose of this study was to look for the proper method for balanced anesthesia using a jugular bulb oxygen saturation (SjO2) that depends on the concentration of propofol used in combination with isoflurane-N2O anesthesia. METHODS: Randomly we divided these patients into group 1 (12 patients), group 2 (12 patients), and group 3 (15 patients). Using a Master TCI and injecting a volatile anesthetic continuously, we injected 2ng/ml of blood concentration to group 1, 3ng/ml to group 2 and 4ng/ml to group 3 and maintained a partial pressure of CO2 in the vein around 30 mmHg during the operation. After induction of anesthesia, injection of propofol, and the dura mater was opened, we measured mean arterial blood pressure, heart rate, respectively, measured partial pressure of CO2, hematocrit, oxygen saturation sampling the arterial blood, measured oxygen saturation sampling jugular bulb. RESULTS: There were no differences of mean arterial blood pressure, heart rate, hematocrit, arterial blood partial pressure of CO2, oxygen saturation, or jugular bulb oxygen saturation among the groups. In addition, there were no statistical differences of variables measured before and after injecting propofol and the dura was opened. For 1 in group 1, 2 in group 2, and 3 in group 3, jugular oxygen saturation dropped below 50% after injecting propofol, but was not verified statistically. CONCLUSIONS: There were no significant hemodynamic effects when we used propofol with the volatile anesthetic in neuroanesthetic management.

Serum S100 beta Protein as a Marker of Cerebral Damage during Cardiopulmonary Bypass / 대한마취과학회지

BACKGROUND: S100 beta protein has been reported to be an early marker of brain injury. It is released from the glial cell and Schwann cell specifically after brain injury, and it,s serum concentration correlates with the severity of injury. The aim of this study was to measure the serum concentration of S100 beta protein during cardiac surgery and to reveal the correlation between cerebral oxygenation and S100 beta protein. METHODS: Eighteen patients undergoing cardiac surgery using cardiopulmonary bypass (CPB) were enrolled in this study. After induction of general anesthesia, the arterial-jugular venous oxygen difference (AjDO2), regional cerebral oxygen saturation (rSO2) and lactate oxygen index (LOI) were measured. They were measured after induction (T0), during CPB (T1) and at the end of CPB (T2). Serum S100beta protein was measured at T0, T2, T3 (5 hours after CPB), and T4 (24 hours after CPB) using an immunoluminometric assay. We observed correlations between rSO2, AjDO2, LOI and the S100beta protein concentration. RESULTS: Serum concentrations of S100 beta protein were 0.18 +/- 0.20, 5.72 +/- 4.25, 1.06 +/- 1.38 and 0.58 +/- 0.44 (micro gram/L) at T0, T2, T3 and T4 respectively (normal value

The Effects of Alfentanil on Mother and Neonate during the Induction of General Anesthesia for a Cesarean Section / 대한마취과학회지

BACKGROUND: During general anesthesia for a cesarean section, light depth of anesthesia frequently leads to maternal awareness and pain responses. The aim of this study was to evaluate the effects of alfentanil on the mother and neonate during a cesarean section. METHODS: Forty four parturients undergoing general anesthesia for an elective cesarean section were enrolled in this study. General anesthesia was induced with propofol 2 mg/kg and succinylcholine 1.5 mg/kg after an intravenous injection of normal saline 0.02 ml/kg for the control group or alfentanil 10microgram/kg for the alfentanil group. After tracheal intubation, anesthesia was maintained with O2 (2 L/min)-N2O (2 L/min)-isoflurane (0.5% end tidal). Mean blood pressure (MBP), heart rate, bispectral index (BIS) and maternal pain responses by an isolated forearm technique were measured every 1 min until delivery. Apgar scores of neonates were measured at 1 min and 5 min after delivery. RESULTS: There were no differences between groups in the MBP, BIS or maternal pain responses. However heart rates were lower in the alfentanil group than in the control group (P = 0.017). CONCLUSIONS: The supplemental administration of alfentanil 10microgram/kg can attenuate the changes in maternal heart rate during general anesthesia for a cesarean section without neonatal Apgar score decline.

Mechanical Obstruction of Right Coronary Artery during Aortic Valve Replacement / 대한흉부외과학회지

Although the incidence is very low, acute mechanical obstruction of the right coronary artery may occur as a cause of right ventricular failure during aortic surgery. In a 67-year-old woman with severe aortic regurgitation, acute right ventricular failure was noticed at the end of cardiopulmonary bypass weaning after an aortic valve replacement with a Hancock II 19 mm bioprosthesis. We suspected mechanical obstruction of the right coronary artery and consequent coronary artery bypass graft to the right coronary artery with right internal mammary artery was performed with success in weaning the bypass. On the postoperative 9th day, the right coronary angiogram revealed obstruction at proximal right coronary artery by plaque emboli. We herein report a clinical case in which the acute right ventricular failure occurred due to mechanical obstruction of the right coronary artery was recovered by coronary artery bypass graft to the right coronary artery.

Experience of Phonocardiogram during the Mitral Valve Replacement / 대한마취과학회지

Phonocardiography is the graphic registration of various bands of the vibratory spectrum. We used the phonocardiogram as a monitoring apparatus. A 62-year-old man was scheduled for mitral valve replacement. After induction of general anesthesia and tracheal intubation, we inserted an esophageal stethoscope attached with a wireless microphone, amplifier, galvanometer and transcription system. The resulting phonocardiogram revealed a pan-systolic murmur. After successful replacement of the mitral valve, the phonocardiogram showed no sign of heart murmur. So we are convinced that the application of the phonocardiogram can be a useful monitoring device for valvular surgery.

Post-hoc Survey for Power of 119 Negative Results in Korean Journal of Anesthesiology / 대한마취과학회지

BACKGROUND: Statistical type II error has seemed to be ignored commonly by medical researchers. To control and present a power value could be helpful to reduce this type of error and to improve a quality of scientific decision making. We performed the post-hoc survey of the power of the negative results in Korean Journal of Anesthesiology (KJA). METHODS: One Hundred nineteen articles with negative results published in KJA during a year of 1997 were selected. We collected the numbers of the sample size and calculated the power of the given negative result only when applicable. And each author's attitude to negative results was taken by arbitrary criteria. RESULTS: Median sample size of these negative results was 16 12 (median interquartile range). We can calculate the power only in 43 articles of 119 negative results. Median power is 18.0% (interquartile range 26.0). In thirty six articles (83.8% of 43) the powers are proved to be under 80.0%. And 22 articles (51.2% of 43) have the powers even under 20.0%. We couldn't find any author who included either power or effect size in the article, and there was only one article in which its authors considered their inadequate number of sample size. CONCLUSIONS: We conclude that authors of KJA tend to ignore statistical type II error. In 119 negative results published in KJA during 1997, the calculated powers were very low and were not reported in the text.

Thoracoscopic Sympathectomy for Hyperhidrosis Lowers Arterial Pressure Measured in Ipsilateral Arm / 대한마취과학회지

BACKGROUND: Thoracoscopic sympathectomy seems to be a safe therapeutic procedure without a severe complication. Hypotension has been often reported as one of postoperative complications, but intraoperative changes in blood pressure (BP) were not studied. However, authors' past experience of thoracic sympathectomy told that intraoperative BP reduction could be observed only when measured in ipsilateral arm. During general anesthesia, BP reduction might be a crucial, which could be associated with complication. Authors conducted this study to establish whether BP reduction is confined to ipsilateral arm, or is systemic phenomenon in thoracoscopic sympathectomy. METHODS: Twenty healthy, male and female patients scheduled for one stage thoracoscopic thoracic sympathectomy were prepared for this study. Without premedication, invasive BP monitoring was taken place in bilateral radial arteries. General anesthesia was induced with low dose of fentanyl, propofol and vecuronium. Endotracheal intubation was done with double lumen tube and anesthesia was maintained with variable concentrations of isoflurane in 100% oxygen. Sympathetomies were done for T2~3 during one lung ventilation. BP and palmar temperature were recorded at arrival, after one lung ventilation, after sympathectomy, 5 min, 10 min, after two lung ventilation. BPs and temperatures were analyzed by time and groups. RESULTS: Concurrent with initiation of sympathectomy, BP was reduced only in ipsilateral radial artery. Mean BP decrement was almost 11% (right side: 80 +/- 11 mmHg -> 71 +/- 15 mmHg; left side: 80 +/- 14 mmHg -> 71 +/- 9 mmHg; both of p<0.05). It was accompanied with ipsilateral palmar temperature elevation (right side: 1.28 degrees C; left side: 1.19 degrees C; both of p<0.05). CONCLUSION: Conclusively, BP reduction in thoracic sympathectomy is a change confined to ipsilateral arm, which seems because of peripheral vasodilation.

A Case Report of Tracheoesophageal Fistula Found during General Anesthesia for Emergency Exploratory Laparotomy / 대한마취과학회지

Tracheoesophageal fistula (TEF) occurs in approximately 1 in 3,000 to 5,000 live births. TEF arises from failure of normal division of proximal foregut into separate respiratory and digestive tracts at 4 weeks' gestation. TEF and esophageal atresia are interrelated anomalies, and TEF usually occurs with esophageal atresia. These are usually diagnosed shortly after birth. However, the diagnosis is often delayed in TEF without esophageal atresia, because babies with this anomaly are usually normal in size and seldom have other anomalies. Therefore, sometimes TEF without esophageal atresia is found during operation for an unrelated condition when positive pressure ventilation causes massive inflation of the gastrointestinal tract. We report a case of TEF in adult patient found during general anesthesia for emergency exploratory laparotomy.

Insertion of Laryngeal Mask Airway with Succinylcholine Administration / 대한마취과학회지

BACKGROUND: The purpose of this study was to assess the effects of succinylcholine(Sch) for insertion of laryngeal mask airway(LMA) during general anesthesia. We compare the bronchoscopic grade, incidence and severity of postoperative sore throat. METHODS: Seventy patients were randomly divided into two groups. The succinylcholine(Sch) group received Sch 1.0 mg/kg, saline group received the same volume of saline 1 minute before the insertion of LMA. Anesthesia was induced with fentanyl 2 g/kg and propofol 2.5 mg/kg. Once the LMA was in the hypopharynx and the cuff inflated, a fiberoptic bronchoscope was immediately passed down through the LMA, and its position was graded from the mask aperture bars. No. of attempts, postoperative sore throat and other complications were also noted. RESULTS: The bronchoscopic grade were aggravated in the Sch group(grade I, n=12; grade II, n=13; grade III, n=10), compared with saline group(22;9;4). The incidence and severity of postoperative sore throat in the recovery room were reduced in the Sch group. No. of attempts were not significantly different. CONCLUSION: The use of Sch for insertion of LMA during general anesthesia aggravated the bronchoscopic grade. However, the incidence and severity of postoperative sore throat could be reduced in the Sch group.

The Effects of Tracheal Intubation with McCoy or Macintosh Laryngoscope on Blood Pressure, Heart Rate / 대한마취과학회지

BACKGROUND: The aim of this study was to compare the cardiovascular changes followed by laryngoscopy with the McCoy laryngoscope blade with those followed by laryngoscopy with the Macintosh laryngoscope blade. METHODS: Forty eight patients were randomly divided into two groups. Following induction with fentanyl 2 mcg/kg and thiopental 5 mg/kg, and muscle relaxation with vecuronium 0.1 mg/kg, the vocal cords were visualized with either the McCoy or the Macintosh laryngoscope blade, then tracheal intubation was performed. Heart rate and arterial blood pressure were measured just before and after laryngoscopy, and 1, 3 and 5 min later. RESULTS: There was a significant increase in both heart rate and arterial blood pressure after tracheal intubation using the Macintosh laryngoscope. Also, use of the McCoy blade resulted in a significant increase in both heart rate and arterial blood pressure. CONCLUSIONS: There was no significant difference on arterial pressure and heart rate to laryngoscopy and tracheal intubation with either the McCoy blade or the Macintosh.

Postoperative convulsion in pediatric surgical patient / 대한마취과학회지

Dilutional hyponatremia as one of the postoperative complications shows around 0.34% in pediatric patients, of which iatrogenic administration of salt-free water is the major cause. Aggressive management should be performed if neurologic symptoms and signs coexist. He/she may be expired of respiratory arrest in severe cases, or permanent neurologic sequelae might persist. We report a case of female pediatric surgical patient who received general anesthesia for Salter innominate osteotomy and had generalized convulsions following 5% dextrose administration. Sodium concentration at immediate postconvulsive period revealed 122 mEq/L, appropriate fluid & electrolyte therapy was performed, then sodium level was successfully restored without any sequelae found. We emphasize that it should be checked out prudently whether postoperative free water is administered in the case of postoperative convulsion, while surgical stimuli and anesthesia itself elevate serum antidiuretic hormone level.

Basic Life Support Training for Medical Students using Skillmeter ResusciTM Anne / 대한마취과학회지

Basic life support training is a part of the curricula of medical school in Anesthesiology practice. Every effort should be made to improve proper mouth-to-mouth breathing and perform correct extemal chest compression. Skillmeter Resusci(TM) Anne (Laerdal(R), Finland) is known to be an extremely valuable aid for accurate and objective training of medical students and for evaluating their performance. Fiftytwo medical students have been trained in basic life support skills and have been evaluated with Skillmeter Resusci Anne. We adopted standards by American Heart Association. As other reports, trainees' outcome was related to psychosomatic skill rather than their knowledge or clinical experience. Repeated training improves the performance capability of artificial ventilation better than external chest compression. At least 6 times of training session seemed required for over ninety percents of the students to reach the desired level of competence in these skills. In summary, a state-of-the-art resuscitaion training manikin displayed an objective individual evaluation and also aroused the interest of the students in CPR basic life support teaching.