BACKGROUND: Unanticipated difficulties during tracheal intubation are related to perioperative morbidity and mortality, but the success of direct laryngoscopic intubation depends largely on clinician's experience and the upper airway anatomy. The lightwand was introduced as alternative intubation technique, but the indicators of difficult lightwand intubation (DLWI) have not been identified. Accordingly authors conducted this study to identify subject factors that affect DLWI, and to compare these with those of difficult laryngoscopic intubation. METHODS: Seventy-three healthy subjects requiring tracheal intubation for elective surgery were enrolled. Anatomic factors, such as, body mass index (BMI), Mallampati classification (MC), inter-incisor gap, thyromental distance, neck circumference, extent of head and neck motion, and Cormack-Lehane grade (CL) were determined and evaluated in terms of their abilities to predict DLWI, which was described using intubation time and number of intubation attempts. Multiple regression analyses were performed to identify predictors using a variable selection technique. RESULTS: Only MC and BMI were found to predict DLWI. The weighted sum of time and number of attempts (r2 = 0.854, P = 0.000) was found to be better predictor of DLWI than their product (r2 = 0.734, P = 0.000). Cormack-Lehane grade was not found to be significantly related to DLWI (P = 0.093). CONCLUSIONS: Of the anatomic factors examined, only Mallampati classification and body mass index were found to predict difficult lightwand intubation.
Body Mass Index ; Head ; Intubation ; Intubation, Intratracheal ; Neck ; Prospective Studies

BACKGROUND: This study was undertaken to evaluate the effect-site concentration of remifentanil to blunt the hemodynamic changes during rapid sequence intubation. METHODS: Eighty patients were enrolled and divided into four groups being assigned with different effect-site concentrations (Ce)of remifentanil of 0, 2, 3, or 4 ng/ml. Patients arrived at the operating room without premedication and their baseline vital signs were recorded. With preoxygenation of 100% O2, remifentanil was infused by target controlled infusion according to patient group. After achievement of a stable level of Ce, propofol 2 mg/kg and rocuronium 1.2 mg/kg were injected and the trachea was intubated one minute later. Hemodynamic changes were recorded at 1, 2, and 3 min after remifentanil infusion, immediately before and after endotracheal intubation, and 1 and 2 min after endotracheal intubation. RESULTS: The 50% effective Ce of remifentanil was 1.4 ng/ml (95% confidence interval, CI: 0.9-1.8) to blunt the increase of mean blood pressure and was 2.4 ng/ml (95% CI: 1.6-3.1) to blunt the increase of heart rate. The 50% Ce for the decrease of mean blood pressure was 2.8 ng/ml (95% CI: 2.2-3.4). CONCLUSIONS: During the rapid sequence intubation, the 50% effective effect site concentration of remifentanil to prevent hemodynamic changes is between 2.4 and 2.8 ng/ml.
Achievement ; Androstanols ; Blood Pressure ; Heart Rate ; Hemodynamics ; Humans ; Intubation ; Intubation, Intratracheal ; Operating Rooms ; Piperidines ; Premedication ; Propofol ; Trachea ; Vital Signs

BACKGROUND: We purposed to systemically review studies investigating the prophylactic effect of both pharmacological and non-pharmacological modalities against rocuronium induced withdrawal movement (RIWM) in the Korean population. METHODS: Literature search was performed using MEDLINE, EMBASE, CENTRAL, Koreamed, KMBASE, KISS and RISS up to March 2014. Randomized controlled trials (RCTs) comparing pharmacological and non-pharmacological interventions with placebo aimed for the Korean population were included. Outcome measures were the incidence and severity of RIWM. We conducted subgroup analyses according to each intervention method. RESULTS: Data were analyzed from 41 RCTs totaling 4,742 subjects. The overall incidence of RIWM was about 80% (range 56-100%). Incidence and severity of RIWM were significantly reduced with lidocaine (risk ratio [RR] 0.60, 95% CI 0.49-0.74; standardized mean difference [SMD] -0.74, 95% CI -1.05 to -0.44), opioids (RR 0.28, 95% CI 0.18-0.44; SMD -1.71, 95% CI -2.09 to -1.34) and hypnotics (RR 0.36, 95% CI 0.25-0.52; SMD -2.20, 95% CI -2.62 to -1.79). Regardless of tourniquet use, lidocaine showed a prophylactic effect against incidence and severity of RIWM: tourniquet (RR 0.36, 95% CI 0.21-0.62; SMD -1.51, 95% CI -2.15 to -0.86); non-tourniquet (RR 0.58, 95% CI 0.47-0.71; SMD -0.74, 95% CI -1.05 to -0.44). Dilution and slow injection of rocuronium decreased incidence and severity of RIWM: dilution (RR 0.47, 95% CI 0.39-0.56; SMD -1.64, 95% CI -2.47 to -0.81); slow injection (RR 0.34, 95% CI 0.17-0.70; SMD -2.13, 95% CI -2.74 to -1.51). CONCLUSIONS: The greater part of pharmacological and non-pharmacological interventions showed prophylactic effect against the incidence and severity of RIWM in the Korean population.
Analgesics, Opioid ; Anesthesia ; Hypnotics and Sedatives ; Incidence ; Lidocaine ; Outcome Assessment (Health Care) ; Tourniquets

BACKGROUND: We performed this study to evaluate the potency and time course of rocuronium-induced neuromuscular block following moderate or severe acute normovolemic hemodilution (ANH) in rabbits. METHODS: Forty five rabbits were randomly assigned to the control (C) group, the moderate ANH (M) group, or the severe ANH (S) group. After stabilization of sevoflurane anesthesia, ANH was achieved by drainage of arterial blood and an intravenous infusion of 6% hydroxyethyl starch, during which hematocrit (Hct) decreased to 26.2 ± 2.5% in the M group and 17.6 ± 2.2% in the S group. We determined dose-response relationships of rocuronium in the three groups and created a time course of the action of 0.6 mg/kg rocuronium. RESULTS: The 50% effective dose (ED50) for rocuronium was 45% and 50% lower in the M and S groups, respectively, than in the C group (50.9 ± 6.3 µg/kg) (P < 0.001). The onset time after 0.6 mg/kg rocuronium was faster in the ANH groups compared with the C group (P < 0.001). The duration of neuromuscular block was prolonged by 38% and 43% in the M and S groups, respectively, compared with the C group (49.1 ± 6.9 min) (P < 0.001). CONCLUSIONS: ANH resulted in high potency, rapid onset, and prolonged duration of rocuronium. However, the severity of ANH did not alter the potency and duration of action of rocuronium.
Anesthesia ; Drainage ; Hematocrit ; Hemodilution* ; Infusions, Intravenous ; Neuromuscular Blockade ; Rabbits* ; Starch

BACKGROUND: The regional cerebral oxygen saturation (rSO2) decreases significantly during ordinary anesthetic recovery in pediatric patients anesthetized with sevoflurane or desflurane. The present study examined the relationship between rSO2 and the clinical parameters associated with the degree of anesthetic recovery. METHODS: Twelve pediatric patients with American Society of Anesthesiologists physical status 1 were assigned randomly to receive anesthesia with sevoflurane or desflurane. All children underwent general anesthesia for minor surgery. After surgery, the rSO2, the age-adjusted MAC fraction of anesthetic concentration (F(E)), and the bispectral index (BIS) were recorded over a 10-minute period. The correlations between rSO2 and candidate predictors, such as F(E), BIS, anesthetic, and duration of anesthesia, were analyzed. RESULTS: All children recovered uneventfully. The lowest observed rSO2 reached 63% and the maximum decrease in rSO2 was 24%. The mean blood pressure and heart rate were maintained within clinical ranges. The decrease in rSO2 correlated positively with the F(E) (r = 0.25, P = 0.00) and the duration of anesthesia (r = 0.24, P = 0.01), and inversely with the use of sevoflurane (r = -0.30, P = 0.00). CONCLUSIONS: Despite normal parameters, cerebral desaturation occurred during the emergence of ordinary general anesthesia even without hemodynamic compromise or arterial desaturation. Cerebral desaturation might be associated with the degree of anesthetic recovery and the use of sevoflurane.
Anesthesia ; Anesthesia, General ; Blood Pressure ; Child ; Heart Rate ; Hemodynamics ; Humans ; Isoflurane ; Methyl Ethers ; Oxygen ; Pediatrics ; Surgical Procedures, Minor

BACKGROUND: Postoperative nausea and vomiting (PONV) remains a common complication of anesthesia. We tried to assess the amount patients were willing to pay for a hypothetical antiemetic that would completely prevent PONV. METHODS: Trained residents interviewed 86 patients, who were scheduled to undergo general anesthesia, and questionnaires were completed. RESULTS: Patients were willing to pay a median of 30,000 won for an antiemetic that would completely prevent PONV. The amounts patients were willing to pay correlated with age, previous history of PONV, and patient income. CONCLUSIONS: Patients assigned a value for avoidance of PONV. It is suggested that more efforts to prevent PONV would be helpful for the increase in patient satisfaction.
Anesthesia ; Anesthesia, General ; Humans ; Patient Satisfaction ; Postoperative Nausea and Vomiting

Post-tonsillectomy hemorrhage (PTH) is the most frequent complication of tonsillectomy, and occasionally results in a lethal outcome. A 21-year-old man (height 180 cm, weight 95 kg) was scheduled for a bilateral tonsillectomy and uvulopalatopharyngoplasty for treatment of obstructive sleep apnea. He required 5 rounds of general anesthesia due to recurrent PTH. The anesthesiologist used sugammadex a total of 3 times to achieve the successful reversal of the deep neuromuscular blockade (NMB) induced by rocuronium. After sugammadex 2 mg/kg was administered, the NMB was reversed in 2 minutes each time. Re-administration of rocuronium within a short time interval after sugammadex may result in unpredictable effects of neuromuscular blocking agents. Sugammadex made it possible to perform a rapid, complete reverse when the residual block was maintained by an incomplete reversal of anticholinesterase.
Anesthesia, General ; Hemorrhage* ; Humans ; Neuromuscular Blockade* ; Neuromuscular Blocking Agents ; Postoperative Hemorrhage ; Sleep Apnea, Obstructive ; Tonsillectomy ; Young Adult

An epiglottic cyst is a common form of laryngeal cysts which are rare causes of upper airway obstruction. A congenital laryngeal cyst always causes neonatal respiratory distress, but an acquired cyst shows very wide spectrum of symptoms such as no specific complaints, dysphagia, respiratory difficulty, or even death according to its size, location, or age. From anesthesiologists' point of view, an asymptomatic undiagnosed laryngeal cyst is a major concern. Unexpectedly, it can cause difficult airway such as 'cannnot intubate' or 'cannot intubate and cannot ventilate' situation during anesthesia. Recently we discovered an undiagnosed epiglottic cyst obscuring laryngeal inlet, leading to difficult intubation during general anesthesia for decompression and fusion of lumbar vertebrae. Fortunately, mask ventilation was possible, and after failed attempts of direct laryngoscopy, we could perform oral fiberoptic bronchoscope-aided intubation. He was discharged 10 days later with no harmful events.
Airway Obstruction ; Anesthesia ; Anesthesia, General ; Bays ; Bronchoscopes ; Decompression ; Deglutition Disorders ; Intubation ; Intubation, Intratracheal ; Laryngoscopy ; Lumbar Vertebrae ; Masks ; Ventilation

BACKGROUND: Neuromuscular blockade of the adductor pollicis muscle may be influenced by hand dominance resulting in conflicting results of several studies. The current study examined whether hand dominance could influence the measurements of neuromuscular blockade with acceleromyography at the adductor pollicis. METHODS: The acceleromyographic responses from 0.6 mg/kg of rocuronium were monitored supramaximally in both hands in 31 patients after induction of anesthesia. Onset, maximum effect, and offset of rocuronium were measured and compared in both hands. The train-of-four (TOF) ratios to 0.9 were recorded in all patients. RESULTS: In total, 27 patients were right-handed and 4 patients were left-handed. The mean supramaximal threshold or initial TOF ratio was not different between dominant and nondominant hands. No statistically significant differences were found between 716 paired TOF ratios in both hands. A correlation was seen between the dominant and nondominant hand (Nondominant = 0.931.Dominant + 1.714, R = 0.929). The analysis by the Bland-Altman plot showed an excellent agreement with a bias of 1.6% and limits of agreement of -21.2 to 24.5%. CONCLUSIONS: Dominant and nondominant hands can be used interchangeably for neuromuscular monitoring at the adductor pollicis.
Androstanols ; Anesthesia ; Bias (Epidemiology) ; Hand ; Humans ; Muscles ; Neuromuscular Blockade ; Neuromuscular Monitoring

The aim of this study was to develop a nonlinear mixed-effects model for the increase in cerebral oximetry (rSO2) during the rapid introduction of desflurane, and to determine the effect of hypocapnia and N2O on the model. Twelve American Society of Anesthesiologist physical status class 1 and 2 subjects were allocated randomly into an Air and N2O group. After inducing anesthesia, desflurane was then increased abruptly from 4.0 to 12.0%. The PET(CO2), PET(DESF) and rSO2 were recorded at 12 predetermined periods for the following 10 min. The maximum increase in rSO2 reached +24-25% during normocapnia. The increase in rSO2 could be fitted to a four parameter logistic equation as a function of the logarithm of PET(DESF). Hypocapnia reduced the maximum response of rSO2, shifted the EC50 to the right, and increased the slope in the Air group. N2O shifted the EC50 to the right, and reduced the slope leaving the maximum rSO2 unchanged. The N2O-effects disappeared during hypocapnia. The cerebrovascular reactivity of rSO2 to CO2 is still preserved during the rapid introduction of desflurane. N2O slows the response of rSO2. Hypocapnia overwhelms all the effects of N2O.
Adult ; Anesthetics, Inhalation/*pharmacology ; *Cerebral Cortex/blood supply/drug effects/physiology ; Cerebrovascular Circulation/*drug effects/physiology ; Female ; Hemodynamics ; Humans ; Hypocapnia/*metabolism ; Isoflurane/*analogs & derivatives/pharmacology ; Male ; Middle Aged ; Models, Theoretical ; Nitrous Oxide/*metabolism ; *Oximetry ; Random Allocation ; Regional Blood Flow/drug effects