Propofol Infusion Associated Metabolic Acidosis in Patients Undergoing Neurosurgical Anesthesia: A Retrospective Study

OBJECTIVE: Propofol and volatile anesthesia have been associated with metabolic acidosis induced by increased lactate. This study was designed to evaluate changes in pH, base excess (BE), and lactate in response to different anesthetic agents and to characterize propofol infusion-associated lactic acidosis. METHODS: The medical records of patients undergoing neurosurgical anesthesia between January 2005 and September 2012 were examined. Patients were divided into 2 groups : those who received propofol (total intravenous anesthesia, TIVA) and those who received sevoflurane (balanced inhalation anesthesia, BIA) anesthesia. Propensity analysis was performed (1 : 1 match, n=47), and the characteristics of the patients who developed severe acidosis were recorded. RESULTS: In the matched TIVA and BIA groups, the incidence of metabolic acidosis (11% vs. 13%, p=1) and base excess (p>0.05) were similar. All patients in the TIVA group who developed severe acidosis did so within 4 hours of the initiation of propofol infusion, and these patients improved when propofol was discontinued. CONCLUSIONS: The incidence of metabolic acidosis was similar during neurosurgical anesthesia with propofol or sevoflurane. In addition, severe acidosis associated with propofol infusion appears to be reversible when propofol is discontinued.

Sugammadex versus neostigmine reversal of moderate rocuronium-induced neuromuscular blockade in Korean patients / 대한마취과학회지

BACKGROUND: Rapid and complete reversal of neuromuscular blockade (NMB) is desirable at the end of surgery. Sugammadex reverses rocuronium-induced NMB by encapsulation. It is well tolerated in Caucasian patients, providing rapid reversal of moderate (reappearance of T2) rocuronium-induced NMB. We investigated the efficacy and safety of sugammadex versus neostigmine in Korean patients. METHODS: This randomized, safety assessor-blinded trial (NCT01050543) included Korean patients undergoing general anesthesia. Rocuronium 0.6 mg/kg was given prior to intubation with maintenance doses of 0.1-0.2 mg/kg as required. Patients received sugammadex 2.0 mg/kg or neostigmine 50 microg/kg with glycopyrrolate 10 microg/kg to reverse the NMB at the reappearance of T2, after the last rocuronium dose. The primary efficacy endpoint was the time from sugammadex or neostigmine administration to recovery of the train-of-four (TOF) ratio to 0.9. The safety of these medications was also assessed. RESULTS: Of 128 randomized patients, 118 had evaluable data (n = 59 in each group). The geometric mean (95% confidence interval) time to recovery of the TOF ratio to 0.9 was 1.8 (1.6, 2.0) minutes in the sugammadex group and 14.8 (12.4, 17.6) minutes in the neostigmine group (P < 0.0001). Sugammadex was generally well tolerated, with no evidence of residual or recurrence of NMB; four patients in the neostigmine group reported adverse events possibly indicative of inadequate NMB reversal. CONCLUSIONS: Sugammadex was well tolerated and provided rapid reversal of moderate rocuronium-induced NMB in Korean patients, with a recovery time 8.1 times faster than neostigmine. These results are consistent with those reported for Caucasian patients.

Feasibility of ultrasound-guided posterior approach for interscalene catheter placement during arthroscopic shoulder surgery / 대한마취과학회지

BACKGROUND: Continuous interscalene block has been known to improve postoperative analgesia after arthroscopic shoulder surgery. This was a prospective study investigating the ultrasound-guided posterior approach for placement of an interscalene catheter, clinical efficacy and complications after placement of the catheter. METHODS: Forty-two patients undergoing elective arthroscopic shoulder surgery were included in this study and an interscalene catheter was inserted under the guidance of ultrasound with posterior approach. With the inplane approach, the 17 G Tuohy needle was advanced until the tip was placed between the C5 and C6 nerve roots. After a bolus injection of 20 ml of 0.2% ropivacaine, a catheter was threaded and secured. A continuous infusion of ropivacaine 0.2% 4 ml/hr with patient-controlled 5 ml boluses every hour was used over 2 days. Difficulties in placement of the catheter, clinical efficacy of analgesia and complications were recorded. All patients were monitored for 48 hours and examined by the surgeon for complications within 2 weeks of hospital discharge. RESULTS: Easy placement of the catheter was achieved in 100% of the patients and the success rate of catheter placement during the 48 hr period was 92.9%. Postoperative analgesia was effective in 88.1% of the patients in the post anesthetic care unit. The major complications included nausea (7.1%), vomiting (4.8%), dyspnea (4.8%) and unintended vascular punctures (2.4%). Other complications such as neurologic deficits and local infection around the puncture site did not occur. CONCLUSIONS: The ultrasound-guided interscalene block with a posterior approach is associated with a success high rate in placement of the interscalene catheter and a low rate of complications. However, the small sample size limits us to draw definite conclusions. Therefore, a well-designed randomized controlled trial is required to confirm our preliminary study.

Paroxysmal atrial fibrillation developed during incomplete epidural anesthesia: A case report / 대한마취과학회지

Atrial fibrillation (AF) is the most common sustained tachyarrhythmia, and occurs in organic heart disease such as rheumatic, atherosclerotic and hypertensive heart disease. In recent studies, the sympathetic and parasympathetic nervous systems have been shown to have important roles in initiating paroxysmal AF. We report here a patient who developed paroxysmal AF that might be a result of an imbalance of the sympathetic-parasympathetic systems due to epidural anesthesia, and that was potentiated by pain with inadequate analgesia. A 69-year-old woman was scheduled for operation of a right-sided ankle fracture. Twenty minutes after epidural drug injection, paroxysmal AF occurred. Even after intravenous administration of esmolol and digoxin, AF continued. After transfer to the intensive care unit, her heart rate gradually decreased and AF disappeared. During perioperative anesthetic management, the proper preoperative prevention and intraoperative treatment are needed in AF high-risk patients.

Effect of muscle relaxant on entropy during propofol anesthesia / 대한마취과학회지

BACKGROUND: The purpose of this study was to investigate whether muscle relaxant affect the values of Entropy, response entropy (RE) or state entropy (SE) during propofol anesthesia. METHODS: Eighty patients (ASA I) scheduled for elective surgery under general anesthesia were randomly assigned to four groups. Anesthesia was maintained at a SE value of 80 (80 +/- 2) using target controlled infusion (TCI) of propofol. After maintaining SE 80 for 5 min, vecuronium 0.1 mg/kg was injected intravenously in group I and same volume of normal saline was intravenously injected in group II. After maintaining SE 60 for 5 min, vecuronium 0.1 mg/kg was injected intravenously in group III and same volume of normal saline was injected intravenously in group IV. The mean arterial pressure, heart rate, SE and RE were measured before anesthetic induction and up to 5 min after vecuronium or normal saline injection in each group. RESULTS: SE and RE were not changed in group II, but significantly decreased in group I (P < 0.05, respectively). In group III and IV, SE and RE were not changed in both groups. There were no significant hemodynamic changes among the four groups. CONCLUSIONS: These results suggest that the effect of muscle relaxant on Entropy vary according to the baseline values of RE or SE during propofol anesthesia.

Tracheal laceration detected by high end-tidal CO2 during endoscopic thyroidectomy / 대한마취과학회지

Endoscopic thyroidectomy is frequently used for cosmetic reasons, such as reducing cervical scarring. Subcutaneous gas insufflation with CO2 is needed to maintain the surgical space, and optimal surgical techniques and careful attention are required when conducting this procedure due to the limited space available for the endoscopic instruments. We report here a case of a tracheal laceration with a tear in the cuff of a reinforced tube, which was detected by an abrupt increase in end-tidal CO2 to 90 mmHg. Reintubation was achieved using a tube exchanger and the patient was effectively ventilated without complications.

The effect of intermittent levator massage with caudal block on management of levator ani syndrome: A case report / 대한마취과학회지

Levator ani syndrome (LAS) is a functional disorder of the pelvic floor muscles in which recurrent and persistent distressing pain is felt in the anus without detectable organic pathology. Eighty one percent of coccygodynia was alleviated by the levator massage when the massage motion was repeated 10 to 15 times on each side of the pelvis daily for 5 or 6 days. The authors encountered the LAS patient for whom successive visit to pain clinic was economic burden. Therefore, the authors managed the patient by intermittent levator massage with caudal block, once a week for 3 times, resulting in two years of pain free status. Intermittent levator massage with caudal block may be as effective as successive levator massage and induce longer painless period in the management of LAS.

Common peroneal nerve palsy after robotic assisted laparoscopic colectomy: A case report / 대한마취과학회지

Common peroneal nerve palsy after surgery with lithotomy position has been widely reported, but it is an unexpected complication after surgery with supine position. We report a patient who developed common peroneal nerve palsy after surgery with supine position. A 55-year old man is planed for robotic assisted laparoscopic right hemicolectomy because of colon cancer. The patient was placed supine with Trendelenburg position at an angle about 5 degrees and tilted left about 15 degrees. The operation is uneventful, but he developed common peroneal nerve palsy on the first postoperative day. The patient was fully recovered with conservative treatment after 2 months. We consider that nerve palsy as a result of compression of common peroneal nerve related to patient positioning. So we should be careful not to develop common peroneal nerve palsy even if the patient was placed in the supine position during robotic assisted surgery.

Comparison of Propofol-Remifentanil and Sevoflurane-Remifentanil Anesthesia for Suspension Laryngoscopic Surgery

BACKGROUND: Suspension laryngoscopic surgery may cause acute hemodynamic changes such as hypertension and tachycardia and requires rapid recovery. The purpose of this study was to compare the hemodynamic responses, and emergence and recovery profiles between propofol-remifentanil and sevoflurane-remfentanil anesthesia. METHODS: Forty patients (ASA I, II) undergoing suspension laryngoscopic surgery were randomly allocated to either a propofol group (Group P) or sevoflurane group (Group S). Anesthesia was induced with target concentration of 5microg/ml using propofol target controlled infusion (TCI) in group P and thiopental sodium 5 mg/kg in group S, respectively. In both groups, after succinylcholine 1 mg/kg IV bolus injection, remifentanil was infused with a target concentration 5 ng/ml using remifentanil TCI for tracheal intubation. Anesthesia was maintained with N2O 2 L/min, O2 2 L/min, remifentanil (2.5-7.0 ng/ml), succinylcholine infusion (0.15 mg/kg/ min) in both groups, with propofol (2.0microg/ml) was used in group P and sevoflurane 3.0 vol% in group S. We compared hemodynamic status, and emergence and recovery profiles during and after operation. RESULTS: MAP and HR after tracheal intubation and suspension laryngoscopy insertion showed significantly smaller changes in group P and were more stable compared with group S. The suction time of the catheter response was shorter in group P compared with group S, and sedation was less deeper in group P than group S. Other recovery profiles were comparable between groups. CONCLUSIONS: During propofol-remifentanil anesthesia, hemodynamics were not increased by intubation or suspension laryngoscopy, and the early emergence and good recovery profiles of patients were appeared favorably compared with sevofluraneremifentanil anesthesia.

The Effect of Remifentanil on Pain during Local Anesthetic Infiltration in Moderately Sedated Plastic Surgery Patients / 대한마취과학회지

BACKGROUND: This randomized study was designed to evaluate the analgesic effectiveness and to determine the optimal dose of remifentanil when administered as intermittent bolus injection during infiltration of local anesthetics for patients undergoing plastic surgery. METHODS: Forty five ASA I or II patients undergoing plastic surgery were randomly assigned to one of the three bolus doses of remifentanil injection. Five minutes after receiving midazolam 0.05 mg/kg IV, remifentanil was injected intravenously one minute before the infiltration of local anesthetics: A bolus of remifentanil 0.25microgram/kg was injected in Group R0.25 (n = 15), 0.50 microgram/kg in Group R0.5 (n = 15), or 0.75microgram/kg in Group R0.75 (n = 15). After assessment of the patients' Observer's Assessment of Alertness/Sedation (OAA/S) scale, the subjective pain level during local anesthetic infiltration was evaluated. Respiratory rate, SpO2, mean blood pressure, and heart rate were recorded during the study period. Postoperative nausea/vomiting and patient's satisfaction were checked by telephone call. RESULTS: OAA/S scale values were similar among the three groups (3-4). The number of the patients who complained of moderate or severe pain level is significantly higher in group R0.25 than in group R0.5 or group R0.75 (P < 0.05). Adverse events such as hypoventilation, desaturation, and bradycardia were observed with significantly high frequency in R0.75 than in other two groups (P < 0.05). All three groups showed no occurrence of hypotension or postoperative nausea/vomiting. CONCLUSIONS: The above results demonstrate that intermittent bolus injection of remifentanil 0.50microgram/kg is recommended to accomplish desirable pain control during local anesthetic infiltration in those who received midazolam 0.05 mg/kg.

The Effect of Combined Ephedrine and Lidocaine Pretreatment on Tracheal Intubation Condition and Maximum Neuromuscular Block after Rocuronium Administration / 대한마취과학회지

BACKGROUND: Rocuronium is a nondepolarizing muscle relaxants used for trying rapid-sequence intubation due to its relatively rapid onset of action and low side effects. Methods to further reduce the onset time of a muscle relaxant include increasing the dose of muscle relaxant, pretreatment for potentiating neuromuscular block of the muscle relaxants or increasing the cardiac output and muscle blood flow. The purpose of this study was to examine the pretreatment effect of combined lidocaine and ephedrine, as a pretreatment, on the onset time and intubation conditions of rocuronium-induced neuromuscular block in adults. METHODS: Sixty ASA physical stati 1 and 2 patients were randomly allocated to four groups. Normal saline 10 ml was administered to Group NS prior to induction, lidocaine (1.5 mg/kg) to Group L, ephedrine (70microgram/kg) to Group E, and combined lidocaine (1.5 mg/kg) and ephedrine (70microgram/kg) to Group LE. Anesthesia was induced with propofol (2.0 mg/kg) and rocuronium (0.6 mg/kg). Intubation was performed 45 seconds after the administration of rocuronium and the intubation conditions then evaluated. The change in the mean arterial pressure and heart rate were checked and compared during the peri-induction periods. RESULTS: There were no differences in the hemodynamics between the four groups. The intubation conditions were graded as good to excellent in 33.3, 53.3, 66.7 and 93.3% of patients in NS, L, E and LE groups, respectively. The intubation conditions in group LE were significantly better than those in group NS (P < 0.05). CONCLUSIONS: The above results demonstrated that pretreatment with a combination of ephedrine and lidocaine, following rocuronium, improves the tracheal intubation conditions.

Anesthetic Management of Cesarean Section in Parturient with Guillain-Barre Syndrome: A case report / 대한마취과학회지

Guillain-Barre syndrome (GBS) is an acute demyelinating polyneuropathy, associated with symmetrical muscle weakness, areflexia, and ascending paralysis. Although it has been reported during all the three trimesters of pregnancy and in the post-partum period, the occurrence of GBS in the third trimester presents a high maternal risk because of respiratory complications and the risk of premature delivery. We report the successful anesthetic management of a parturient with GBS.

Implementing a Communication Skills Course for Undergraduate Medical Students / 한국의학교육

PURPOSE: The purposes of this study were to describe a viable communication skills course for medical students and to discuss how to improve it for better teaching. METHODS: The subjects were a communication skills course and one hundred thirty three third-year medical students who participated in the course in 2006. Program evaluation by students was conducted using questionnaire at the end of each session and the entire course. RESULTS: The communication course was named as "Medical Communication Skills". Basic communication skills and interview skills for specific clinical situations were taught. We used experiential leaning methods such as standardized patient (SP) interviews with feedback. Students rated the course highly especially for SP-based practice sessions and student group projects. The course evaluation indicated that the students considered communication skills to be significantly more important as a clinical competency after the completion of the course. CONCLUSION: We confirmed that the communication skills course was well perceived by medical students and they preferred experiential learning methods more than didactic methods.

Hypothermia Induced by Incorrect Monitoring of Core Temperature: A case report / 대한마취과학회지

A 55-year-old man was scheduled to undergo revisional total hip arthroplasty under general anesthesia. During the operation, a warm blanket and fluid warmer were applied, with his body temperature maintained at 35oC, as assessed with the use of a temporal-artery thermometer. In the course of the operation, severe bleeding developed, which required a massive transfusion of packed red blood cells and other blood components to correct the electrolyte and pH balances; the infusion of cardiovascular drugs was also preformed. However, the hemodynamic status of the patient deteriorated to severe hypotension, with atrial fibrillation, non-sustaining paroxysmal ventricular tachycardia and ventricular fibrillation. The patient was re-evaluated, and it was realized the temporal-artery thermometer had been incorrectly monitored, causing hemodynamic deterioration, which was assessed as hypothermia from a nasopharyngeal temperature of 29 degrees C. Active warming methods, including a condensed humidifier, and warming of the fluids and blood compounds with a rapid infusion system, were instigated, resulting in stabilization of the patient's hemodynamic status and the disappearance of his dysrhythmia.

Anesthetic Management of Cesarean Section in Parturient with Systemic Lupus Erythematosus Complicated by Pneumothorax: A case report / 대한마취과학회지

Systemic lupus erythematosus (SLE) is a multisystem inflammatory disorder characterized by autoantibody production. It has a strong female preponderance and occurs primarily in the reproductive years. Although involvement of the respiratory system is common in SLE, pneumothorax is one of the less frequently reported pulmonary complications and carries with it a grave prognosis. We report a successful anesthetic management of a parturient with SLE complicated by pneumothorax.

Effect of Fresh Gas Flow on the Work of Breathing of Closed Circuit Anesthesia Using Semiclosed Circuit System / 대한마취과학회지

BACKGOUND: The effect of anesthetic techniques, such as closed circuit anesthesia (CCA) using semiclosed circuit system and semiclosed circuit anesthesia (SCCA), on the work of breathing has not been studied yet in detail. This study was purposed to compare the work of breathing according to anesthetic technique (CCA, SCCA). METHODS: Thirty patients were assigned to receive either SCCA group or CCA group (n = 15). Anesthesia was induced with propofol 2 mg/kg with 2% lidocaine 1 ml. Two percents isoflurane with O2 and N2O 2 L/min were given for 10 min to patients initially to wash in functional residual capacity and the breathing circuits. In SCCA group, anesthesia was maintained with 2% isoflurane in O2 2 L/min and N2O 2 L/min throughout the surgery. In CCA group, O2 was reduced to 200 ml/min and N2O to 100 ml/min with isoflurane vaporizer setting adjusted to 4% for anesthesia maintenance. When the operation was ended, the vaporizer setting of isoflurane deceased to zero and then O2 was increased to 4 L/min for the arousal of the patient. We measured the inspiratory/expiratory concentration of isoflurane, end-tidal CO2, the hemodynamic parameters, the change of airway pressure, the work of breathing, and compliance at anesthetic induction and emergence in both groups. RESULTS: There were no significant differences in the inspiratory/expiratory concentrations of isoflurane, the hemodynamic parameters, end-tidal CO2, airway pressure, the work of breathing and compliance between the groups. CONCLUSIONS: CCA using semiclosed circuit system does not increase the work of breathing compared to SCCA.

Changes in the Autonomic Function after Thoracic Sympathicotomy by Clipping / 대한마취과학회지

BACKGROUND: A thoracic sympathicotomy with cauterization has been reported to decrease cardiac sympathetic activity. The purpose of this study was to investigate immediate changes in autonomic function after thoracic sympathicotomy by clipping. METHODS: Autonomic function test such as heart rate response to deep breathing (HRDB), Valsalva ratio (VR), 30/15 ratio and systolic blood pressure change response to standing (delta SBP) were measured before (baseline) and 2 hr after the T3-4 sympathicotomy by clipping in 12 patients with palmar hyperhidrosis. Baseline data were also compared with data obtained from 18 matched patients who were planned to take minor surgery. Anesthesia was induced with 5 mg/kg thiopental sodium and 0.6 mg/kg rocuronium. The anesthesia was maintained with 2.0-2.5 vol% sevoflurane, 2 L/min nitrous oxide and 2 L/min oxygen. RESULTS: There were no significant differences of the autonomic test results between control and clip group before operation. In the clip group, there were no significant differences of autonomic test results between before and after clipping. CONCLUSIONS: This study showed that the response to sympathetic stimulation was not changed after thoracic sympathicotomy by clipping.

Does Epidural Clonidine Decrease the Sevoflurane Concentration for Maintaining the BIS 50? / 대한마취과학회지

BACKGROUND: The aim of this study was to investigate the influence of epidural clonidine on the BIS, and its potential dose-sparing effect on the sevoflurane requirement for maintaining the BIS 50. METHODS: Forty ASA I or II patients aged 20 to 65, undergoing lower abdominal, gynecologic surgery under general anesthesia, were randomly allocated to either a 10 ml epidural normal saline injection group (n = 20) or a 10 ml epidural clonidine 3microgram/kg mixed with normal saline injection group (n = 20). They received 5 mg/kg thiopental sodium and 0.1 mg/kg vecuronium bromide for induction, with no premedication. After surgical incision, the sevoflurane concentration was controlled to maintain the BIS 50. Epidural saline or clonidine was then injected and end-tidal sevoflurane concentration to maintain the BIS 50, the heart rate (HR) and mean arterial pressure (MBP) were measured every 5 min over a 20 minute period. RESULTS: The end-tidal sevoflurane concentration in the clonidine group decreased by 27.5% after the epidural clonidine injection (1.49 +/- 0.23 vol% vs. 1.08 +/- 0.27 vol%; P0.05). There were no changes in the heart rate and mean blood pressure in either group. CONCLUSIONS: Epidural clonidine causes a significant decrease in the BIS, and lowers the end-tidal sevoflurane concentration required for maintaining the BIS 50.

Effect of Muscle Relaxant to Bispectral Index during Propofol Anesthesia / 대한마취과학회지

BACKGROUND: There have been some conflicting reports showing that the muscle relaxant affect the level of bispectral index (BIS) during various condition of anesthesia. The purpose of this study was to investigate whether muscle relaxant affects the level of BIS during propofol anesthesia. METHODS: Eighty patients (ASA class I or II , 20-55 yrs) scheduled for elective surgery under general anesthesia were randomly assigned to four groups. Anesthesia was maintanined at a BIS level of 60 by propofol target controlled infusion (TCI) with air-oxygen (2 L/min : 2 L/min). After maintaining BIS 60 with spontaneous breathing, normal saline 0.05 mg/kg was iv injected in group I and vecuronium bromide 0.1 mg/kg was iv injected in group II. After maintaining at a BIS level of 40 with assisted ventilation, normal saline 0.05 mg/kg was iv injected in group III and vecuronium bromide 0.1 mg/kg was iv injected in group IV. The BIS, mean arterial pressure, and heart rate were measured before anesthetic induction and up to 10 min after normal saline or vecuronium bromide injection in each group. RESULTS: BIS was not changed in group I, but BIS significantly decreased in group II (P < 0.05). In group III and IV, BIS were not changed in both group. There were no hemodynamic changes among the four groups. CONCLUSIONS: These result suggest that the effect of muscle relaxant on BIS vary according to the level of BIS during propofol anesthesia.

Transient Polyuria during SevofluraneAnesthesia : A report of two cases

Polyuria is occasionally observed after general anesthesia with sevoflurane. Usually the onset of polyuria is abrupt and remission is spontaneous, so it's not so easy to do detailed investigation. The authors came across with two cases of polyuria during general anesthesia with sevoflurane which occurred so early around one hour after induction of anesthesia. Both cases revealed no special problem like central diabetes insipidus.