Predicted EC50 and EC95 of Remifentanil for Smooth Removal of a Laryngeal Mask Airway Under Propofol Anesthesia

PURPOSE: The purpose of this study was to determine the effect-site concentration (Ce) of remifentanil in 50% of patients (EC50) and 95% of patients (EC95) for smooth laryngeal mask airway (LMA) removal in adults under propofol and remifentanil anesthesia. MATERIALS AND METHODS: Twenty-five patients of ASA physical status I-II and ages 18-60 years who were to undergo minor gynecological or orthopedic surgery were assessed in this study. Anesthesia was induced and maintained with propofol and remifentanil target-controlled infusion (TCI). Remifentanil was maintained at a predetermined Ce during the emergence period. The modified Dixon's up-and-down method was used to determine the remifentanil concentration, starting from 1.0 ng/mL (step size of 0.2 ng/mL). Successful removal of the LMA was regarded as absence of coughing/gagging, clenched teeth, gross purposeful movements, breath holding, laryngospasm, or desaturation to SpO2<90%. RESULTS: The mean+/-SD Ce of remifentanil for smooth LMA removal after propofol anesthesia was 0.83+/-0.16 ng/mL. Using isotonic regression with a bootstrapping approach, the estimated EC50 and EC95 of remifentanil Ce were 0.91 ng/mL [95% confidence interval (CI), 0.77-1.07 ng/mL] and 1.35 ng/mL (95% CI, 1.16-1.38 ng/mL), respectively. CONCLUSION: Our results showed that remifentanil TCI at an established Ce is a reliable technique for achieving safe and smooth emergence without coughing, laryngospasm, or other airway reflexes.

Ultrasound-guided central cluster approach for the supraclavicular brachial plexus block: a case series / 대한마취과학회지

There are many different approaches to ultrasound-guided supraclavicular brachial plexus block (US-SCBPB), and each has a different success rate and complications. The most commonly performed US-SCBPB is the corner pocket approach in which the needle is advanced very close to the subclavian artery and pleura. Therefore, it may be associated with a risk of subclavian artery puncture or pneumothorax. We advanced the needle into the central part of the neural cluster after penetrating the sheath of the brachial plexus in US-SCBPB. We refer to this new method as the "central cluster approach." In this approach, the needle does not have to advance close to the subclavian artery or pleura. The aim of this study was to evaluate the clinical outcomes of the central cluster approach in US-SCBPB.

Analysis of pre-operative aspartate aminotransferase and alanine aminotransferase in 14,185 pediatric patients

BACKGROUND: The aim of this study was to investigate the efficacy of routine pre-anesthetic aspartate aminotransferase (AST) and alanine aminotransferase (ALT) tests for detection of hepatic abnormalities and usefulness in perioperative management. METHODS: The laboratory findings of 14,185 pediatric patients younger than 18 years from October 2004 to December 2010 were investigated by retrospective review of medical records. All of the patients had undergone preoperative AST and ALT screening. RESULTS: Among the 14,185 patients, 221 patients experienced elevation of both AST and ALT. However, only 21 patients were suspicious for hepatic disease defined as persistent elevation of AST and ALT preoperatively. Among the 221 patients with elevation of both AST and ALT, 20 patients were examined by additional abdominal ultrasonography and hepatic abnormalities were detected in 13 of these patients (65%) and 40 patients were consulted to the department of pediatrics or internal medicine. CONCLUSIONS: In this single-center, retrograde study, the usefulness of preoperative routine AST and ALT testing was shown to be limited for detection of hepatic abnormalities in pediatric patients undergoing general anesthesia. Further multi-center, large-scale investigation would be required.

Profound Hypotension after an Intradermal Injection of Indigo Carmine for Sentinel Node Mapping / 한국유방암학회지

Intradermal injections of indigo carmine for sentinel node mapping are considered safe and no report of an adverse reaction has been published. The authors described two cases of profound hypotension in women that underwent breast-conserving surgery after an intradermal injection of indigo carmine into the periareolar area for sentinel node mapping.

Total intravenous anesthesia for Kartagener's syndrome: A case report

Kartagener's syndrome (KGS) is an autosomal recessive disorder which possible to link the occurrence of abnormal ciliary movement and abnormal position of the body organs. Considering the fact that airway ciliary function plays an important role in the primary pulmonary defense mechanism, prevent the ciliodepressant actions are also important for anesthetic management. We described successful anesthetic management of a 44-year-old male scheduled for endoscopic sinus surgery who had a history of frequent epistaxis, anosmia and situs inversus totalis. Anesthesia was induced and maintained with propofol and remifentanil using a target controlled infusion device.

Anesthetic management of HELLP syndrome complicating primary antiphospholipid syndrome: A case report / 대한마취과학회지

Antiphospholipid syndrome (APS) is defined as an autoimmune disorder characterized by recurrent thrombosis or obstetrical morbidity. A 29-year-old woman who was diagnosed with APS underwent emergency cesarean delivery at 23 weeks' gestation. She had a seizure attack and her laboratory findings were: AST/ALT 1459/1108 IU/L, LDH 1424 IU/L, 30% hematocrit, a platelet count of 43 x 10(3)/ml and urine protein (4+). We describe the anesthetic experience of catastrophic HELLP syndrome with antiphospholipid syndrome and we review the relevant literature.

Effects of different sample volumes on arterial blood gas and electrolytes testing

BACKGROUND: Insufficient sample volume can cause unnecessary blood loss and inaccurate arterial blood gas and electrolytes testing. The aim of this study was to determine the adequate sample volume, that is required for accurate arterial blood gas and electrolyte testing from arterial catheters. METHODS: Patients had four different arterial blood samples (0.2 ml, 0.4 ml, 0.6 ml and 1 ml [control], respectively) taken sequentially in random order. Samples were analyzed for pH, PaCO2, PaO2, hematocrit, Na+, K+, Ca2+ and Mg2+ using NOVA blood gas analyzer. RESULTS: A total of 27 patients were recruited for the study. All sample volumes tested provided the results of pH, PaCO2, PaO2 and hematocrit that were statistically similar to control values. However, the results of electrolytes (K+, Ca2+ and Mg2+) in all sample volumes tested were significantly lower than the control values and an increasing sample volume equated to blood results trending closer to those obtained with the control sample. CONCLUSIONS: This study showed that there is not one sample volume that will provide accurate results for all blood components. The study tested a variety of sample volumes and found that although even small sample volume of 0.2 ml provided accurate results for pH, PaCO2, PaO2 and hematocrit. No sample volume that was tested provided accurate results for K+, Ca2+ and Mg2+.

The effects of peripheral hypothermia on monitoring the recovery from deep neuromuscular blockade with rocuronium

BACKGROUND: The skin temperature is often decreased during anesthesia because of a cool ambient temperature in the operating room. Contractility of the muscles may be affected by lowering the muscle temperature. This study was designed to verify that efforts to maintain normothermia on the monitored arm can make recovery from deep neuromuscular blockade more reliable. METHODS: A total of 60 patients were enrolled in this study. Each patient was randomly assigned to group 1 (the monitored arm was shielded with a passive warming protector) or group 2 (the monitored arm was was exposed to the ambient operating room temperature). Conventional inhalation anesthesia was induced with propofol and alfentanil, and this was maintained with O2, N2O and isoflurane. The twitch response of the adductor pollicis muscle was recorded. After calibration of the TOF watch(R), 0.6 mg/kg of rocuronium was injected. During anesthesia, the post tetanic count (PTC) was checked every 5 to 6 minutes until the first response to a train-of-four (TOF) stimulations appeared. The ambient operating room temperature, the core temperature and the skin temperature were checked simultaneously. RESULTS: The skin temperature of group 2 was lower than that of group 1 (33.89 +/- 0.81 degreesC and 35.41 +/- 0.45 degreesC, respectively, P < 0.05). When the data was plotted with the equation y=be(-ax), this equation well represented the data of group 1 (R2 = 0.82), but it did not well represent the data of group 2 (R2 = 0.54). CONCLUSIONS: During recovery from deep neuromuscular blockade with using rocuronium, it may be desirable to maintain normothermia at the thenar area for a better recovery time from a given PTC.

The effect of heating insufflation gas on acid-base alterations and core temperature during laparoscopic major abdominal surgery / 대한마취과학회지

BACKGROUND: Carbon dioxide (CO2) has different biophysical properties under different thermal conditions, which may affect its rate of absorption in the blood and the related adverse events. The present study was aimed to investigate the effects of heating of CO2 on acid-base balance using Stewart's physiochemical approach, and body temperature during laparoscopy. METHODS: Thirty adult patients undergoing laparoscopic major abdominal surgery were randomized to receive either room temperature CO2 (control group, n = 15) or heated CO2 (heated group, n = 15). The acid-base parameters were measured 10 min after the induction of anesthesia (T1), 40 min after pneumoperitoneum (T2), at the end of surgery (T3) and 1 h after surgery (T4). Body temperature was measured at 15-min intervals until the end of the surgery. RESULTS: There were no significant differences in pH, PaCO2, the apparent strong ion difference, the strong ion gap, bicarbonate ion, or lactate between two groups throughout the whole investigation period. At T2, pH was decreased whereas PaCO2 was increased in both groups compared with T1 but these changes were not significantly different. Body temperatures in the heated group were significantly higher than those in the control group from 30 to 90 min after pneumoperitoneum. CONCLUSIONS: The heating of insufflating CO2 did not affect changes in the acid-base status and PaCO2 in patients undergoing laparoscopic abdominal surgery when the ventilator was set to maintain constant end-tidal CO2. However, the heated CO2 reduced the decrease in the core body temperature 30 min after the pneumoperitoneum.

The effects of the oxygen flow rate on heart rate variability in the PACU after TIVA

BACKGROUND: Oxygen increases the cardiac vagal tone, blood pressure, systemic vascular resistance and vascular tone in healthy adults.This study assessed the autonomic tone according to different oxygen flow rates via different types of masks with using the heart rate variability (HRV) in the PACU after total intravenous anesthesia (TIVA). METHODS: We prospectively studied 27 patients after TIVA in the PACU.The 5 L group received oxygen via a simple mask with an oxygen rate of 5 L/min and the 10 L group received oxygen via a mask with a reservoir bag at a rate of 10 L/min in the PACU. We evaluated the HRV at the point of stabilization before anesthesia (BL), 5 min in the PACU (PACU 5), 30 min in the PACU (PACU 30) and 60 min in the PACU (PACU 60). RESULTS: In the 5 L group, the nuHF was increased to 42.4 +/- 24.2 at 60 min in the PACU as compared with 27.1 +/- 19.1 at 5 min in the PACU.In the 5 L group, the LFHFr was decreased to 2.3 +/- 2.1 at PACU 60 as compared with 6.6 +/- 9.7 at PACU 5 and the nuLF was decreased to 56.9 +/- 23.2 at PACU 60 as compared with 72.9 +/- 19.0 at PACU 5.There were no significant changes between the two groups at PACU 5, PACU 30 and PACU 60.The oxygen saturation was increased at PACU 60 compared with PACU 5 in the two groups. CONCLUSIONS: These finding indicates that 1 h of oxygen administration with 5 L/min during emergence from anesthesia increased the relative vagal tone, and the arterial blood pressure is stable irrespective of the oxygen flow rate.

A case of Churg-Strauss syndrome that underwent endoscopic sinus surgery under total intravenous anesthesia: A case report

Churg-Strauss syndrome is also known as allergic granulomatosis, and it is a rare systemic vasculitis that may affect multiple organ systems, and particularly the lungs.A 42-year-old woman with Churg-Strauss syndrome underwent endoscopic sinus surgery under total intravenous anesthesia with propofol and remifentanil. Anesthesia was performed uneventfully, but there were several issues of concern that evolved regarding the perioperative management of a patient with this syndrome.

The clinical effective dose of rocuronium for lightwand tracheal intubation after induction with alfentanil, propofol, and low concentrations of sevoflurane / 대한마취과학회지

BACKGROUND: The aim of this study was to determine the clinical effective dose of rocuronium for tracheal intubation using a lightwand after induction with propofol, alfentanil, and a low concentration of sevoflurane. METHODS: Twenty-eight adults scheduled to undergo elective surgery lasting less than one hour were enrolled in this study. All patients received alfentanil (10 microgram/kg) and propofol (1.5 mg/kg) for the induction of anesthesia. Tracheal intubation using a lightwand was attempted 3 minutes after administering rocuronium and mask ventilation with 2 vol% of sevoflurane. The initial rocuronium dose was 0.5 mg/kg. The rocuronium dose for consecutive patients, determined by Dixon's up-and-down method, was increased or decreased by 0.05 mg/kg according to the result of the previous patient. The mean arterial pressure and heart rate were recorded before induction, 1 min before intubation, 1 and 2 min after intubation. RESULTS: The 50% clinical effective dose (cED(50)) of rocuronium for tracheal intubation using a lightwand was 0.20 +/- 0.05 mg/kg according to Dixon's up and down method. Isotonic regression revealed the cED(50) and cED(95) (95% confidence intervals) to be 0.20 mg/kg (0.10-0.3 mg/kg) and 0.35 mg/kg (0.16-0.49 mg/kg), respectively. CONCLUSIONS: The cED(50) and cED(95) of rocuronium for tracheal intubation using the lightwand were 0.20 mg/kg and 0.35 mg/kg, respectively, after induction with alfentanil, propofol, and a low concentration of sevoflurane.

Atrial flutter associated with high pressure pneumoperitoneum during laparoscopic gastrectomy: A case report

Pneumoperitoneum associated with carbon dioxide (CO2) insufflation may induce alterations in electrocardiographic variables, which may produce severe atrial and ventricular arrhythmias.We now present a case in which atrial flutter developed after CO2 insufflation in a patient undergoing laparoscopic subtotal gastrectomy.Although the ECG change was reversed after desufflation, one should keep in mind the increased propensity to atrial and ventricular arrhythmias during laparoscopy with high intra-abdominal pressure.

Unexpected Intra-operative Pulmonary Thromboemolism during Elective Mastoidectomy: A Case Report / 대한구급학회지

We report on a 45-year-old patient who sustained an intra-operative pulmonary thromboembolism during elective mastoidectomy under general anesthesia. At the end of surgery, the patient developed hemodynamic compromise and exhibited T wave inversion on electrocardiogram. Echocardiography showed an echogenic mass in the right pulmonary artery and pulmonary hypertension. Pulmonary thromboembolism is rare in the field of otolaryngology and head and neck surgery; however, it may develop, resulting in a fatal outcome. It is thus important to establish the diagnosis early and prevent such serious complications.

Anesthetic management of a patient with pulmonary arteriovenous malformation under total intravenous anesthesia : A case report / 대한마취과학회지

A 23-year-old woman with pulmonary arteriovenous malformation was scheduled for open reduction and internal fixation due to her mandible fracture. Total intravenous anesthesia using propofol and remifentanil was selected as the anesthetic method in order to avoid the inhibition of hypoxic pulmonary vasoconstriction and the exacerbation of intrapulmonary shunting. After the standard monitoring devices were applied, anesthesia was then induced and maintained with a target controlled infusion of propofol and remifentanil in the range of 2.5-3.0 microg/ml and 2-3 ng/ml, respectively. Anesthesia was performed uneventfully and the patient was discharged without complication.

Effects of pneumoperitoneum and position changes on blood pressure variability and heart rate variability during laparoscopy-assisted vaginal hysterectomy / 대한마취과학회지

BACKGROUND: This study was designed to assess the effects of pneumoperitoneum and positional changes on the autonomic nervous system (ANS) in laparoscopy-assisted vaginal hysterectomy (LAVH) patients. METHODS: Systolic blood pressures and R-R interval were recorded for 5 minutes in 22 patients, and then power spectral analyses were conducted to evaluate the ANS. The following variables were measured at various positions: preinduction (BASE), prepneumoperitoneum (PREPP), pneumoperitoneum at head-down (PP), normoperitoneum at supine (POSTPP). RESULTS: High frequency of heart rate variability (HRVHF), Low frequency of heart rate variability (HRVLF), Low frequency of blood pressure variability (BPVLF), LF/HF ratios of HRV (LFHFr) were significantly lower than that of BASE at PREPP. HRVHF, HRVLF, BPVLF were significantly lower than that of BASE at PP. At PP, normalized HF of HRV (nuHF) is significantly lower than that of BASE and normalized LF of HRV (nuLF) is significantly higher than that of BASE and PREPP (P < 0.05). LFHFr was significantly lower than that of BASE and significantly higher than that of PREPP at PP. At POSTPP, HRVHF, HRVLF, BPVLF were significantly lower than that of BASE. But, BPVLF at POSTPP was higher than that of PP. CONCLUSIONS: We conclude that the pneumoperitoneum and trendelenburg positions caused sympathetic activation in LAVH patients.

The effect of sequential compression device on hypotension in the sitting position during shoulder arthroscopy; a comparison with elastic stocking / 대한마취과학회지

BACKGROUND: The sitting position under general anesthesia is associated with hemodynamic instability. The purpose of this study was to compare the efficacy of a sequential compression device (SCD) with that of elastic stockings (ES) in reducing the incidence of hypotension and other hemodynamic instability in the sitting position during shoulder arthroscopy. METHODS: Fifty-one patients undergoing shoulder arthroscopy were randomly assigned into one of three groups to receive no treatment (control group, n = 17), SCD (SCD group, n = 17) or ES (ES group, n = 17). Hemodynamic variables were measured 5 min after induction of anesthesia (baseline values), and every 1 min from 1 to 5 min after raising the patient to a 70degrees sitting position (T1-5) with the beach-chair. RESULTS: The incidences of hypotension (proportion, 95% CI) were 12/17 (0.71, 0.47-0.87), 5/16 (0.31, 0.14-0.56) and 7/15 (0.47, 0.25-0.70) in the control, SCD and ES group, respectively. The incidence was significantly lower in the SCD group than that in the control group (P = 0.038). At 1 min after sitting position, mean arterial pressure in the control group was significantly lower than that in the SCD group and it was significantly decreased from the baseline value. CONCLUSIONS: SCD could significantly reduce the incidence of hypotension with less hemodynamic instability in the sitting position during shoulder arthroscopy. Although the incidence of hypotension was decreased with the elastic stocking, there was no statistical significance.

Comparison of recovery times from deep neuromuscular blockade between single bolus and continuous infusion of rocuronium

BACKGROUND: To prevent sudden unexpected movement of patients during surgery, muscle relaxants are used to maintain intense neuromuscular blockade.They are administered by intermittent bolus or continuous infusion.Rocuronium is often used for continuous infusion because it is known to lack cumulative effects. The purpose of this study was to compare recovery times from intense neuromuscular block to reappearance of muscle twitches after 0.1 Hz single twitch stimulation. MATERIALS AND METHODS: Seventy five patients were randomized to one of 3 groups.Patients in group 1 were administered a single bolus of rocuronium; groups 2 and 3 were given continuous infusion of rocuronium for 1 and 2 h, respectively.During anesthesia, neuromuscular blockade was monitored by TOF-watch(R) and regulated so as not to exceed more than 5 (PTC) during the infusion. After infusion, PTC was counted every 5 min until single twitch heights had reappeared and the time till the twitch reappeared was calculated. RESULTS: There was a good correlation between the time it took to observe a PTC and the first response of TOF time in each group.In a parallelism test, there were no significant differences. There were also no significant differences in recovery times from PTC to the reappearance of a single twitch between groups. CONCLUSIONS: There are no significant differences in recovery times-from deep neuromuscular blockade to reappearance of single twitch-regardless of the infusion time.When a PTC occurs during deep neuromuscular blockade, it may predict the remaining time of reappearance of a single twitch response.

The dose-dependent effect of alfentanil on the rocuronium induced withdrawal in children

BACKGROUND: The injection of rocuronium causes pain and withdrawal responses.This study was designed to determine an optimal dose of alfentanil to prevent the withdrawal responses associated with injection of rocuronium in children. METHODS: One hundred and ten ASA physical status I and II pediatric patients were randomly allocated into four groups; Group C (control; normal saline 3 ml, n = 28), Group A5 (alfentanil 5microgram/kg, n = 28), Group A10 (alfentanil 10microgram/kg, n = 27) and Group A15 (alfentanil 15microgram/kg, n = 27). After the induction of anesthesia with 5 mg/kg of thiopental sodium, the test drug was injected over 20 seconds, respectively. After one minute, rocuronium 0.6 mg/kg was injected over 5 seconds. The patient's response after injection was graded using a four-point scale. Additionally, the mean arterial pressure and heart rate were recorded upon arrival in the operating room, as well as 1 min before and 1 min after tracheal intubation. RESULTS: The incidence of withdrawal responses was 96%, 61%, 19% and 19% in groups C, A5, A10 and A15, respectively. The incidence and severity of withdrawal responses in group A10 and A15 were lower than group C and A5. CONCLUSIONS: After thiopental injection, alfentanil 10microgram/kg prevent the withdrawal responses on injecting rocuronium in pediatric patients.

Effect of Different Doses of Rocuronium on Intubation and the Incidence of Acute Laryngeal Sequelae / 대한마취과학회지

BACKGROUND: In ambulatory surgery, which is of short duration, anesthesiologists often do not use a muscle relaxant, or any other induction technique which could facilitate muscle relaxation for endotracheal intubation.Incomplete muscle relaxation, however, results in vocal cord movement and the possibility of damage to the vocal cords and adjacent structure.The aim of this study was to evaluate the macroscopic sequelae of intubation on vocal cord and laryngeal structure and assess postoperative sore throat or hoarseness. METHODS: 100 patients with class I or II ASA physical status were enrolled in this study.It was divided into two groups, Group C (conventional intubation dose of rocuronium; 0.6 mg/kg) and group L (low intubation dose 0.45 mg/kg).Anesthesia was induced with 10microgram/kg of alfentanil and 2.0 mg/kg of propofol i.v.Intubation was performed 90 second after rocuronium injection and the intubation condition was checked.Macroscopic sequelae ofthe laryngeal structure were evaluated using a flexible fiberoptic bronchoscope. After completion of surgery, the patient was asked to report sore throat or hoarseness. RESULTS: Macroscopic sequelae, such as erythema or hemorrhage, were statistically different between the two groups.There were no cases of minimal hemorrhage of either vocal cords or of the arryepiglottic folds in group C whereas there were two cases in group L.There was no statistical difference in incidence and severityof sore throat or hoarseness between the two groups. CONCLUSIONS: Although there were more macroscopic effects in the vocal cords and aryepiglottic folds, a low intubation dose of rocuronium can be used during surgery of short duration without fear of any significant sore throat or hoarseness after surgery.