Korean clinical practice guideline for perioperative red blood cell transfusion from Korean Society of Anesthesiologists / 대한마취과학회지

BACKGROUND@#Considering the functional role of red blood cells (RBC) in maintaining oxygen supply to tissues, RBC transfusion can be a life-saving intervention in situations of severe bleeding or anemia. RBC transfusion is often inevitable to address intraoperative massive bleeding; it is a key component in safe perioperative patient management. Unlike general medical resources, packed RBCs (pRBCs) have limited availability because their supply relies entirely on voluntary donations. Additionally, excessive utilization of pRBCs may aggravate prognosis or increase the risk of developing infectious diseases. Appropriate perioperative RBC transfusion is, therefore, crucial for the management of patient safety and medical resource conservation. These concerns motivated us to develop the present clinical practice guideline for evidence-based efficient and safe perioperative RBC transfusion management considering the current clinical landscape.@*METHODS@#This guideline was obtained after the revision and refinement of exemplary clinical practice guidelines developed in advanced countries. This was followed by rigorous evidence-based reassessment considering the healthcare environment of the country.@*RESULTS@#This guideline covers all important aspects of perioperative RBC transfusion, such as preoperative anemia management, appropriate RBC storage period, and leukoreduction (removal of white blood cells using filters), reversal of perioperative bleeding tendency, strategies for perioperative RBC transfusion, appropriate blood management protocols, efforts to reduce blood transfusion requirements, and patient monitoring during a perioperative transfusion.@*CONCLUSIONS@#This guideline will aid decisions related to RBC transfusion in healthcare settings and minimize patient risk associated with unnecessary pRBC transfusion.

Korean clinical practice guideline for perioperative red blood cell transfusion from Korean Society of Anesthesiologists / 대한마취과학회지

BACKGROUND: Considering the functional role of red blood cells (RBC) in maintaining oxygen supply to tissues, RBC transfusion can be a life-saving intervention in situations of severe bleeding or anemia. RBC transfusion is often inevitable to address intraoperative massive bleeding; it is a key component in safe perioperative patient management. Unlike general medical resources, packed RBCs (pRBCs) have limited availability because their supply relies entirely on voluntary donations. Additionally, excessive utilization of pRBCs may aggravate prognosis or increase the risk of developing infectious diseases. Appropriate perioperative RBC transfusion is, therefore, crucial for the management of patient safety and medical resource conservation. These concerns motivated us to develop the present clinical practice guideline for evidence-based efficient and safe perioperative RBC transfusion management considering the current clinical landscape. METHODS: This guideline was obtained after the revision and refinement of exemplary clinical practice guidelines developed in advanced countries. This was followed by rigorous evidence-based reassessment considering the healthcare environment of the country. RESULTS: This guideline covers all important aspects of perioperative RBC transfusion, such as preoperative anemia management, appropriate RBC storage period, and leukoreduction (removal of white blood cells using filters), reversal of perioperative bleeding tendency, strategies for perioperative RBC transfusion, appropriate blood management protocols, efforts to reduce blood transfusion requirements, and patient monitoring during a perioperative transfusion. CONCLUSIONS: This guideline will aid decisions related to RBC transfusion in healthcare settings and minimize patient risk associated with unnecessary pRBC transfusion.

Influence of electrocautery-induced electromagnetic interference on quantitative electroencephalographic monitoring of hypnosis during general anesthesia: comparison between the ADMS® and the BIS VISTATM / 대한마취과학회지

BACKGROUND: Hypnosis monitors analyze small-amplitude electrical signals transmitted from the brain that could be exposed to the electromagnetic field that occurs around the body during electrocautery (ECT). We investigated the influence of ECT on hypnosis monitoring during anesthesia. METHODS: We simultaneously monitored BIS and uCON during 50 gynecologic oncology surgeries. During the episodes of ECT, we compared the absolute difference (a-Diff) between the baseline index and the most deviated index after ECT over either 30–60 s (ECT30–60) or more than 60 s (ECT > 60) between the monitors. We also investigated the bias and the limits of agreement between the monitors. RESULTS: Between the two monitors, the a-Diff of ECT30–60 was 1.4 ± 1.1 for the BIS, which was significantly greater than 0.6 ± 0.9 for the uCON (P = 0.003), and the a-Diff of ECT > 60 was 16.5 ± 8.2 for the BIS, which was also significantly greater than 1.4 ± 1.3 for uCON (P 60 was significantly greater than that during ECT30–60 (P 60 (P = 0.056). The estimated bias between the monitors was 6.3 ± 9.8 and 95% limits agreement was –12.3 to 25.0. CONCLUSIONS: Prolonged ECT intervention might lead to spurious estimations of quantitative EEG indexes. Therefore, hypnosis should be clinically assessed in combination with scrutinized judgment of relevant clinical symptoms and signs for hypnosis.

Changes in cerebral oxygen saturation and early postoperative cognitive function after laparoscopic gastrectomy: a comparison with conventional open surgery / 대한마취과학회지

BACKGROUND: Laparoscopic gastrectomy requires a reverse-Trendelenburg position and prolonged pneumoperitoneum and it could cause significant changes in cerebral homeostasis and lead to cognitive dysfunction. We compared changes in regional cerebral oxygen saturation (rSO2), early postoperative cognitive function and hemodynamic variables in patients undergoing laparoscopic gastrectomy with those patients that underwent conventional open gastrectomy. METHODS: Sixty patients were enrolled in this study and the patients were distributed to receive either laparoscopic gastrectomy (laparoscopy group, n = 30) or open conventional gastrectomy (open group, n = 30). rSO2, end-tidal carbon dioxide tension, hemodynamic variables and arterial blood gas analysis were monitored during the operation. The enrolled patients underwent the mini-mental state examination 1 day before and 5 days after surgery for evaluation of early postoperative cognitive function. RESULTS: Compared to baseline value, rSO2 and end-tidal carbon dioxide tension increased significantly in the laparoscopy group after pneumoperitoneum, whereas no change was observed in the open group. No patient experienced cerebral oxygen desaturation or postoperative cognitive dysfunction. Changes in mean arterial pressure over time were significantly different between the groups (P < 0.001). CONCLUSIONS: Both laparoscopic and open gastrectomy did not induce cerebral desaturation or early postoperative cognitive dysfunction in patients under desflurane anesthesia. However, rSO2 values during surgery favoured laparoscopic surgery, which was possibly related to increased cerebral blood flow due to increased carbon dioxide tension and the effect of a reverse Trendelenburg position.

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.

Changes in thyroid hormones in patients undergoing liver transplantation

BACKGROUND: Critical illness that requires major surgery is often associated with non-thyroidal illness syndrome (NTIS). The characteristic feature of NTIS is low serum triiodothyronine (T3) levels, and in severe illness, the levels of serum thyroxine (T4) are also low in the absence of a rise in thyroid stimulating hormone (TSH). However, little is known about the changes in thyroid hormones during and after liver transplantation (LT). This study was conducted in order to evaluate the intra- or postoperative changes in thyroid hormones. METHODS: Twenty-two patients who underwent LT were enrolled. Serum levels of triiodothyronine (T3), thyroxine (T4), thyroid stimulating hormone (TSH), free T3 (FT3) and free T4 (FT4) were measured immediately after the induction of anesthesia (T1), at the end of the anhepatic period (T2), at the end of the surgical procedure (T3), and at 24 hours (T4) and 120 hours postoperatively (T5). RESULTS: The mean levels of T3, T4, FT3, FT4 and TSH were significantly decreased throughout the study when compared with the T1 value. The mean levels of T3, T4 FT3 and TSH were below the normal range from T2, T4 and T5. CONCLUSIONS: We suggest that LT may induce NTIS by at least postoperative day 5. In the future, longer follow-up studies, and the effects of thyroid hormones on the prognosis and determination of the advantages and disadvantages of T3 replacement therapy to these patients will be required.

The effect of injection speed on remifentanil-induced cough in children / 대한마취과학회지

BACKGROUND: Remifentanil sometimes elicits cough during induction of anesthesia, as with the use of other fentanyl congeners. We designed this study to investigate the incidence of remifentanil-induced cough (RIC) in children and to evaluate the effect of injection speed on RIC. METHODS: One hundred twenty ASA physical status I-II patients, aged 3-12 yr, undergoing general anesthesia were enrolled in the study. Patients were randomly assigned to one of the three groups. Patients in Group R30 received remifentanil 1.5 microg/kg at a constant rate over 30 s. Patients in Group R45 received remifentanil 1.5 microg/kg over 45 s, and patients in Group R60 received remifentanil 1.5 microg/kg over 60 s, respectively. Episodes of cough were recorded and graded as mild (1-2), moderate (3-4), or severe (5 or more). Mean arterial pressure (MAP), heart rate (HR), and SpO2 were recorded on arrival in the operating room (baseline) and 1 min after remifentanil infusion. RESULTS: The incidence of RIC was 33.3% in Group R30 (13 of 39 patients), 17.9% in Group R45 (7 of 39 patients), and 5.0% in Group R60 (2 of 40 patients). Patients in Group R60 had a significantly lower incidence of RIC than those in Group R30 (P = 0.001). The MAP, HR, and SpO2 values were not significantly different between groups. CONCLUSIONS: When intravenous remifentanil 1.5 microg/kg was administered in pediatric patients, the incidence of RIC decreased from 33 to 5% by increasing the injection time from 30 to 60 s. Remifentanil should be administered slowly over 60 s in children to suppress cough during anesthesia induction.

Interferon-gamma Enzyme-Linked Immunospot Assay in Patients with Tuberculosis and Healthy Adults / 결핵및호흡기질환

BACKGROUND: Interferon-gamma assays based on tuberculosis (TB)-specific antigens have been utilized for diagnosing and ruling out latent TB and active TB, but their utility is still limited for TB incidence countries. The aim of this study is to understand the clinical utility of enzyme-linked immunospot (ELISpot) assays among patients with clinically suspected TB and healthy adults in clinical practices and community-based settings. METHODS: The ELISpot assays (T SPOT.TB, Oxford Immunotec, UK) were prospectively performed in 202 patients. After excluding those with indeterminate results, 196 were included for analysis: 41 were TB patients, 93 were non-TB patients, and 62 were healthy adults. RESULTS: The sensitivity and negative predictive values of the T SPOT.TB assays for the diagnosis of TB were 87.8% and 89.1%, respectively, among patients with suspected TB. The agreement between the tuberculin skin test (10-mm cutoff) and the T SPOT.TB assay was 66.1% (kappa=0.335) in all participants and 80.0% (kappa=0.412) in TB patients. Among those without TB (n=155), a past history of TB and fibrotic TB scar on chest X-rays were significant factors that yielded positive T SPOT.TB results. There was a significant difference in the magnitude of T SPOT.TB spot counts between TB patients and non-TB patients or healthy adults. CONCLUSION: The T SPOT.TB assay appeared to be a useful test for the diagnostic exclusion of TB. A positive result, however, should be cautiously interpreted for potential positives among those without active TB in intermediate TB incidence areas.

False selection of syringe-brand compatibility and the method of correction during target-controlled infusion of propofol / 대한마취과학회지

BACKGROUND: We evaluated volumetric differences of syringe brand compatibilities, and investigated the impact of false brand settings on target-controlled infusion (TCI) and their methods of correction. METHODS: Gravimetric measurement of 10 ml bolus infusions was performed using BD Plastipak (BDP) and Terumo compatible syringes, while setting to 7 different kinds of brand compatibilities (BDP, Sherwood Monoject, BD Perfusion, Braun Perfusor, Braun Omnifix, Fresenius Injectomat, and Terumo). To investigate the performance of TCI using BDP with a false setting to Terumo (BDPTERUMO) and Terumo to BDP (TERUMOBDP), 24 TCI targeting 4.0 microg/ml of effect-site concentration (Ceff) of propofol were performed. Subsequently, another 24 TCI were evaluated for simple corrections of false settings at 30 min. We also investigated 24 TCI using active corrections (fill-up for BDPTERUMO, evacuation for TERUMOBDP) based on the pharmacokinetics of propofol. The Ceff at 30 min of TCI and time to normalize to +/- 5% of target concentration (T+/-5%target) were compared. RESULTS: The Ceff of BDPTERUMO showed negative bias and 17.2% inaccuracy, and the Ceff of TERUMOBDP showed positive bias and 19.5% inaccuracy. The Ceff at 30 min showed no difference between the methods of correction in BDPTERUMO or TERUMOBDP. The T+/-5%target in both the active corrections was significantly shorter than that of each simple corrections (P < 0.001). CONCLUSIONS: False brand setting of syringe proportionally maintained different predicted concentrations as much as the volumetric differences of syringe brand. Based on the results, it is proposed that correction methods based on pharmacokinetics could effectively normalize the differences, without giving up the wrong TCI.

Impact of priming the infusion system on the performance of target-controlled infusion of remifentanil / 대한마취과학회지

BACKGROUND: The start-up behavior of syringe and syringe pump is known to be one of the causes of inaccurate intravenous infusion. This study evaluated the method of priming the infusion system (PRIMING), and its impact on the target-controlled infusion (TCI) of two remifentanil diluents. METHODS: PRIMING was performed using an evacuation of 2.0 ml to the atmosphere prior to TCI. Forty-eight TCI, using 50 microg/ml (Remi50) or 20 microg/ml (Remi20) of diluents, were performed targeting 4.0 ng/ml of effect-site concentration (Ceff), with PRIMING or not. The gravimetrical measurements of the delivered infusates reproduced actual Ceff. The bolus amount and time to reach 95% target were compared. RESULTS: Without PRIMING, Remi50 infused less bolus (43 +/- 23 %) than Remi20 (19 +/- 9 %) (P = 0.003), and showed more delayed increase of Ceff (11.2 +/- 4.0 min) than Remi20 (7.4 +/- 0.4 min) (P = 0.028). However, PRIMING significantly decreased the deficit of the bolus (2 +/- 1%), as well as the delay of the increase of Ceff in Remi50 (1.2 +/- 0.2 min) (both P < 0.001). In addition, with PRIMING, the start-up bolus showed minimal difference to the nominal bolus (1 and 2%), and Ceff were increased to 4.0 +/- 0.1 ng/ml at the expected time of peak effect, irrespective of the diluents. CONCLUSIONS: Proper operation of the syringe pump used in the priming of the syringe may be helpful in reduction of the inaccuracy of TCI, particularly during the early phase of infusion, or the infusion of a more concentrated diluent.

Clinical and epidemiological characteristics of Korean patients with hepatitis C virus genotype 6

BACKGROUND/AIMS: The distribution of hepatitis C virus (HCV) genotypes varies geographically. In Korea, genotypes 1 and 2 comprise more than 90% of HCV infections, while genotype 6 is very rare. This study compared the clinical and epidemiological characteristics of patients with genotype 6 HCV infection with those infected with HCV genotypes 1 and 2. METHODS: This was a prospective, multicenter HCV cohort study that enrolled 1,173 adult patients, of which 930 underwent HCV genotype analysis, and only 9 (1.0%) were found to be infected with genotype 6 HCV. The clinical and epidemiological parameters of the genotypes were compared. RESULTS: The patients with genotype 6 HCV had a mean age of 41.5 years, 77.8% were male, and they had no distinct laboratory features. A sustained virologic response (SVR) was observed in four (67%) of six patients who received antiviral therapy. Risk factors such as the presence of a tattoo (n=6, 66.7%), more than three sexual partners (n=3, 33.3%), and injection drug use (n=3, 33.3%) were more common among genotype 6 patients than among genotypes 1 or 2. CONCLUSIONS: The epidemiology and treatment response of patients infected with genotype 6 HCV differed significantly from those with genotypes 1 or 2, warranting continuous monitoring.

Effect of tracheal lidocaine on intubating conditions during propofol-remifentanil target-controlled infusion without neuromuscular blockade in day-case anesthesia / 대한마취과학회지

BACKGROUND: Lidocaine is a useful intravenous and topical adjunct to facilitate tracheal intubation. We evaluated the effect of tracheal lidocaine on tracheal intubating conditions without neuromuscular blocking agent and hemodynamics during anesthesia induction with propofol and remifentanil target-controlled infusion (TCI). METHODS: Fifty patients, aged 18-60 years, scheduled for closed reduction of fractured nasal bone were randomly assigned to the control group (n = 25) or lidocaine group (n = 25). Anesthesia was induced with propofol-remifentanil TCI with the effect-site concentration of 5 microg/ml and 5 ng/ml. Four minutes after the start of propofol-remifentanil TCI, 4% lidocaine or saline 3 ml was instilled to larynx and trachea, and intubation was performed 1 min later. Acceptable intubation was defined as excellent or good intubating conditions. Hemodynamic data, induction and recovery profiles were recorded. RESULTS: Intubating condition was clinically acceptable in 13 out of 25 (52%) patients in the control group and in 22 out of 25 (88%) in the lidocaine group, and there was a significant difference between the two groups in regard to acceptable intubating conditions (P = 0.005). Mean arterial pressure change over time was significantly different between the two groups. There were no significant differences in the heart rate between the two groups. CONCLUSIONS: This study demonstrated that laryngotracheal administration of 4% lidocaine could increase the percentage of acceptable conditions for tracheal intubation during propofol and remifentanil anesthesia without neuromuscular blockade.

The efficacy of the time-scheduled decremental continuous infusion of fentanyl for postoperative patient-controlled analgesia after total intravenous anesthesia / 대한마취과학회지

BACKGROUND: Intravenous fentanyl has been used for acute postoperative pain management, but has not always provided reliable adequate analgesia, including patient-controlled analgesia (PCA). The purpose of this study was to investigate the efficacy of time-scheduled decremental infusion of fentanyl for postoperative analgesia. METHODS: Ninety-nine patients, aged 20-65 years, undergoing laparoscopic-assisted hysterectomy using total intravenous anesthesia (TIVA) were randomly assigned into one of the three groups. Their background infusions of fentanyl diluent (2 ml/hr of diluent was equivalent with 0.5 microg/kg/hr of fentanyl) with PCA were maintained at the fixed-rate of 2 ml/hr until the postoperative 24 hr (FX2-2-2), or at the decremental rates of 6.0, 4.0, 2.0 ml/hr (D6-4-2) and 8.0, 4.0, 2.0 ml/hr (D8-4-2). The visual analogue score (VAS), incidence of inadequate analgesia, frequency of PCA intervention, and side effects were evaluated. RESULTS: VAS was significantly higher in FX2-2-2 than in D6-4-2 and D8-4-2 until postoperative 3 hr (P < 0.05). After postoperative 4 hr, VAS was significantly higher in FX2-2-2 than D8-4-2 (P < 0.05). The incidence of inadequate analgesia of FX2-2-2 was significantly greater than D6-4-2 (P = 0.038) and D8-4-2 (P < 0.001) until postoperative 1 hr. None of the patients had ventilatory depression, and postoperative nausea and vomiting were not significant among the groups. CONCLUSIONS: The time-scheduled decremental background infusion regimens of fentanyl, based on the pharmacokinetic model, could provide more effective postoperative pain management after TIVA, and the side effects and the risk for morbidity were not different from the fixed-rate infusion regimen.

Cross-simulation between two pharmacokinetic models for the target-controlled infusion of propofol / 대한마취과학회지

BACKGROUND: We investigated how one pharmacokinetic (PK) model differed in prediction of plasma (Cp) and effect-site concentration (Ceff) using a reproducing simulation of target-controlled infusion (TCI) with another PK model of propofol. METHODS: Sixty female patients were randomly assigned to TCI using Marsh PK (Group M) and TCI using Schnider PK (Group S) targeting 6.0 microg/ml of Cp of propofol for induction of anesthesia, and loss of responsiveness (LOR) was evaluated. Total and separate cross-simulation were investigated using the 2 hr TCI data (Marsh TCI and Schnider TCI), and we investigated the reproduced predicted concentrations (MARSHSCH and SCHNIDERMAR) using the other model. The correlation of the difference with covariates, and the influence of the PK parameters on the difference of prediction were investigated. RESULTS: Group M had a shorter time to LOR compared to Group S (P < 0.001), but Ceff at LOR was not different between groups. Reproduced simulations showed different time courses of Cp. MARSHSCH predicted a higher concentration during the early phase, whereas SCHNIDERMAR was maintained at a higher concentration. Volume and clearance of the central compartment were relevant to the difference of prediction, respectively. Body weight correlated well with differences in prediction between models (Rsqr = 0.9821, P < 0.001). CONCLUSIONS: We compared two PK models to determine the different infusion behaviors during TCI, which resulted from the different parameter sets for each PK model.

Behavioral and Healthcare-Associated Risk Factors for Chronic Hepatitis C Virus Infection in Korea

The risk factors related to hepatitis C virus (HCV) infection showed geographic and temporal differences. We investigated HCV-related risk factors in Korea where intravenous drug use (IVDU) is uncommon. The HCV-related risk factors were investigated in a prospective, multicenter chronic HCV cohort (n = 711) using a standardized questionnaire in four university hospitals. The results were compared with those of 206 patients with chronic liver diseases not related to either of HCV or hepatitis B virus infection (comparison group). The IVDU was found in 3.9% and remote blood transfusion (> or = 20 yr ago) in 18.3% in HCV cohort group, while that in comparison group was in none and 5.3%, respectively. In a multivariate logistic analysis, transfusion in the remote past (odds ratio [OR], 2.99), needle stick injury (OR, 4.72), surgery (OR, 1.89), dental procedures (OR, 2.96), tattooing (OR, 2.07), and multiple sexual partners (2-3 persons; OR, 2.14, > or = 4 persons; OR, 3.19), were independent risk factors for HCV infection. In conclusion, the major risk factors for HCV infection in Korea are mostly related to conventional or alterative healthcare procedures such as blood transfusion in the remote past, needle stick injury, surgery, dental procedure, and tattooing although multiple sex partners or IVDU plays a minor role.

Behavioral and Healthcare-Associated Risk Factors for Chronic Hepatitis C Virus Infection in Korea

The risk factors related to hepatitis C virus (HCV) infection showed geographic and temporal differences. We investigated HCV-related risk factors in Korea where intravenous drug use (IVDU) is uncommon. The HCV-related risk factors were investigated in a prospective, multicenter chronic HCV cohort (n = 711) using a standardized questionnaire in four university hospitals. The results were compared with those of 206 patients with chronic liver diseases not related to either of HCV or hepatitis B virus infection (comparison group). The IVDU was found in 3.9% and remote blood transfusion (> or = 20 yr ago) in 18.3% in HCV cohort group, while that in comparison group was in none and 5.3%, respectively. In a multivariate logistic analysis, transfusion in the remote past (odds ratio [OR], 2.99), needle stick injury (OR, 4.72), surgery (OR, 1.89), dental procedures (OR, 2.96), tattooing (OR, 2.07), and multiple sexual partners (2-3 persons; OR, 2.14, > or = 4 persons; OR, 3.19), were independent risk factors for HCV infection. In conclusion, the major risk factors for HCV infection in Korea are mostly related to conventional or alterative healthcare procedures such as blood transfusion in the remote past, needle stick injury, surgery, dental procedure, and tattooing although multiple sex partners or IVDU plays a minor role.

A target-controlled infusion regimen for reducing remifentanil-induced coughs / 대한마취과학회지

BACKGROUND: This study evaluates the effectiveness of the target-controlled infusion (TCI) of remifentanil through stepwise increases in the effect-site concentration (Ceff) in preventing coughs. METHODS: In a preliminary study, we randomly selected 140 patients to receive remifentanil through two-step increases in Ceff (1.0 ng/ml to 4.0 ng/ml: Group R1-4; 2.0 ng/ml to 4.0 ng/ml: Group R2-4). Based on the results of the preliminary study, we employed another sample of 140 patients and implemented a three-step increase in TCI (1.0 ng/ml to 2.0 ng/ml to 4.0 ng/ml: Group R1-2-4). We then compared this treatment with direct targeting based on 4.0 ng/ml TCI (Group R4). We recorded the episodes of coughs, rating them as mild (1-2), moderate (3-4), or severe (5 or more). RESULTS: In Group R1-4, one patient (1.5%) coughed during the first step, and five (7.3%) coughed during the second step. In Group R2-4, nine (13.2%) coughed during the first step, but none coughed during the next step. Only one patient had a mild cough during the three-step increase in TCI, that is, patients in Group R1-2-4 were significantly less likely to cough than those in Group R4 (P < 0.001). CONCLUSIONS: Stepwise increases in the TCI of remifentanil reduced the incidence of remifentanil-induced coughing, and the three-step increase in TCI nearly eliminated remifentanil-induced coughing.

Tongue bite in a patient with tracheostomy after prone position: A case report / 대한마취과학회지

A 22-year-old man underwent an operation for posterolateral fusion of the lumbar spine at L3-5. He was ventilated via a tracheostomy site in a prone position for 210 minutes. Ventilator function and eyeballs were checked periodically. After changing his position to supine for the wake-up test, it was noticed that his tongue was self-inflicted and looked to be cut unless immediate decompression was applied. After several manual attempts to open the mouth failed, anesthesia depth was deepened with thiopental sodium and neuromuscular blocker to decompress and reposition the tongue into the intraoral cavity. Minimal teeth marks and scarring remained after seven months without any complications.

Comparison of the effects of sevoflurane and propofol on core body temperature during laparoscopic abdominal surgery / 대한마취과학회지

BACKGROUND: A decrease in core body temperature caused by heat distribution depends on the anesthetic agent used. The purpose of this study is to investigate the effects of sevoflurane and propofol on core temperature during laparoscopic major abdominal surgery requiring pneumoperitoneum of more than 90 min. METHODS: Fifty adult patients undergoing laparoscopic major abdominal surgery were randomly assigned to either a sevoflurane group (n = 25) or a propofol group (n = 25). In the sevoflurane group, anesthesia was induced with propofol 2 mg/kg, remifentanil 1.0 microg/kg, and maintained with 0.8-2.0 vol% sevoflurane and 0.1-0.2 microg/kg/min remifentanil. In the propofol group, anesthesia was induced with the effect-site concentration of propofol of 5.0 microg/ml and remifentanil 4 ng/ml, and maintained with the effect-site concentration of propofol of 2-3.5 microg/ml and remifentanil 3-5 ng/ml. Core body temperature was measured with an esophageal stethoscope with a temperature sensor after the start of the pneumoperitoneum (baseline) and at 15-min intervals until completion of surgery. RESULTS: During the study period, core temperature was comparable between the two groups. When compared with baseline values, core temperatures in both groups were significantly decreased 45 min after pneumoperitoneum. CONCLUSIONS: This study demonstrated that in patients undergoing prolonged laparoscopic surgery, a decrease in core body temperature during sevoflurane-remifentanil anesthesia was not different than propofol-remifentanil anesthesia, and the incidence of hypothermia of the two groups did not differ.

Comparison of effect-site concentration of remifentanil for tracheal intubation with the lightwand and laryngoscopy during propofol target-controlled infusion / 대한마취과학회지

BACKGROUND: Target-controlled infusion (TCI) of propofol and remifentanil can provide satisfactory intubating conditions without a neuromuscular blocking agent. We compared the effect-site concentration of remifentanil required for intubation with the lightwand and the Macintosh laryngoscope during propofol TCI without a neuromuscular blocking agent in adult patients. METHODS: Forty-nine patients were randomly assigned to the lightwand group (n = 25) or the direct laryngoscope group (n = 24). Anesthesia was induced by propofol TCI with an effect-site concentration of 5.4 microg/ml. Two minutes after start of propofol TCI, remifentanil was administered at the predetermined effect-site concentration. The effect-site concentration of remifentanil was determined using Dixon's up-and-down method (0.5 ng/ml as a step size). The first patient in each group was tested at 4.5 ng/ml of remifentanil. Tracheal intubation was performed 2 min after the start of remifentanil TCI. Acceptable intubation was defined as an excellent or good intubating conditions. RESULTS: Using a modified Dixon's up and down method, the EC50 +/- SD of remifentanil in the lightwand and laryngoscope groups was 4.75 +/- 0.71 ng/ml and 5.08 +/- 0.52 ng/ml, respectively; there was no statistically significant difference between the groups (P = 0.373). CONCLUSIONS: The effect-site concentration of remifentanil for acceptable intubation with the lightwand and Macintosh laryngoscope in 50% of adults did not differ during propofol TCI without a neuromuscular blocking agent.