Background: Remimazolam is a new ultra short-acting benzodiazepine originally developed as an improved version of midazolam. Recent studies have demonstrated non-inferiority of remimazolam to propofol in general anesthesia. However, to date, few studies have investigated the induction bolus dose of remimazolam required to achieve general anesthesia. We aimed to determine the 95% effective dose (ED95) of remimazolam bolus required to achieve loss of consciousness (LOC) and the appropriate doses for different age groups. Methods: Patients aged 20–79 years with the American Society of Anesthesiologists physical status of I or II were enrolled in this study. A total of 120 patients were included representing young, middle-aged, and elderly groups. Loss of eyelash reflex and verbal response after the administration of remimazolam was considered successful LOC. The ED95 of remimazolam was determined using a biased coin up-and-down design with sequential allocation and the isotonic regression method. Results: The ED95 of remimazolam for induction of general anesthesia was 0.367 mg/kg (95% CI [0.277, 0.392]) in the young group, 0.369 mg/kg (95% CI [0.266, 0.394]) in the middle-aged group, and 0.249 mg/kg (95% CI [0.199, 0.288]) in the elderly group. During the study period, none of the patients required rescue medications for hypotension or bradycardia. Conclusions This study investigated the ED95 of remimazolam bolus for anesthesia induction. The precise dosing of the ED95 can help maintain hemodynamic stability during the induction of anesthesia.

BACKGROUND: The methods of arrangement of combined intravenous parallel infusions using anti-reflux valve (ARV), with and without anti-syphon valve (ASV) that could decrease occlusion alarm delay were investigated. METHODS: Occlusion challenge tests were mainly performed as bench experiments of four kinds of multiple parallel infusions (10 ml/h and 50 ml/h infusions), which were connected at the proximal or distal portion of ARV, with or without ASV. Alarm threshold was set to 1000 mmHg. Occlusion alarm delays and the compliances of the infusion systems were compared among groups. RESULTS: Without ASV, compared to 10 ml/h infusion alone distal to anti-reflux valve, 50 ml/h infusion distal to anti-reflux valve reduced the mean alarm delay from 416 +/- 7 s to 81 +/- 3 s (P < 0.001). Compared to 50 ml/h infusion alone, combined 10 ml/h and 50 ml/h infusion distal to ARV prolonged the alarm delay from 81 +/- 3 s to 133 +/- 6 s (P < 0.001). However, combined infusions distal to ARV with ASV significantly reduced the alarm delay from 133 +/- 6 s to 74 +/- 5 s (P < 0.001), and also reduced the compliance of the infusion system from 2.31 +/- 0.12 to 1.20 +/- 0.08 microl/mmHg (P < 0.001). CONCLUSIONS: The infusion setup of faster infusion rate, lower compliant system using ASV could effectively decrease occlusion alarm delay during multiple intravenous parallel infusions using ARV.
Anesthetics ; Compliance ; Equipment Safety ; Infusions, Intravenous

BACKGROUND: We investigated the correction methods following wrong-settings of emulsion concentrations of propofol as a countermeasure against erroneous target-controlled infusions (TCI). METHODS: TCIs were started with targeting 4.0 microg/ml of effect-site concentration (C(eff)) of propofol, and the emulsion concentrations were selected for 2.0% instead of 1.0% (FALSE(1-2), n = 24), or 1.0% instead of 2.0% (FALSE(2-1), n = 24). These wrong TCIs were corrected at 3 min after infusion start. During FALSE(1-2), the deficit was filled up while injecting after equilibrium (n = 12), or while overriding (n = 12). During FALSE(2-1), the overdose was evacuated while targeting C(eff) (n = 12) or targeting plasma concentration (C(p)) (n = 12). The gravimetrical measurements of TCI reproduced the C(p) and C(eff) using simulations. The reproduced C(eff) at 3 min (C(eff-3min)) and the time to be normalized within +/- 5% of target C(eff) (T(+/-5%)), were compared between the correction methods. RESULTS: During the wrong TCI, C(eff-3min) was 1.98 +/- 0.01 microg/ml in FALSE(1-2), and 7.99 +/- 0.05 microg/ml in FALSE(2-1). In FALSE(1-2), T(+/-5%) was significantly shorter when corrected while overriding (3.9 +/- 0.25 min), than corrected after equilibrium (6.9 +/- 0.05 min) (P < 0.001). In FALSE(2-1), T(+/-5%) was significantly shorter during targeting C(p) (3.6 +/- 0.04 min) than targeting C(eff) (6.7 +/- 0.15 min) (P < 0.001). CONCLUSIONS: The correction methods, based on the pharmacokinetic and pharmacodynamic characteristics, could effectively and rapidly normalize the wrong TCI following erroneously selections of the emulsion concentration of propofol.
Drug Delivery Systems ; Infusion Pumps ; Infusions, Intravenous ; Plasma ; Propofol*

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.
Anesthesia* ; Anesthesia, Intravenous ; Arterial Pressure ; Heart Rate ; Hemodynamics ; Humans ; Intubation ; Larynx ; Lidocaine* ; Nasal Bone ; Neuromuscular Blockade* ; Piperidines ; Propofol ; Trachea

BACKGROUND: During beating heart surgery, the accuracy of cardiac output (CO) measurement techniques may be influenced by several factors. This study was conducted to analyze the clinical agreement among stat CO mode (SCO), continuous CO mode (CCO), arterial pressure waveform-based CO estimation (APCO), and transesophageal Doppler ultrasound technique (UCCO) according to the vessel anastomosis sites. METHODS: This study was prospectively performed in 25 patients who would be undergoing elective OPCAB. Hemodynamic variables were recorded at the following time points: during left anterior descending (LAD) anastomosis at 1 min and 5 min; during obtuse marginal (OM) anastomosis at 1 min and 5 min: and during right coronary artery (RCA) anastomosis at 1 min and 5 min. The variables measured including the SCO, CCO, APCO, and UCCO. RESULTS: CO measurement techniques showed different correlations according to vessel anastomosis site. However, the percent error observed was higher than the value of 30% postulated by the criteria of Critchley and Critchley during all study periods for all CO measurement techniques. CONCLUSIONS: In the beating heart procedure, SCO, CCO and APCO showed different correlations according to the vessel anastomosis sites and did not agree with UCCO. CO values from the various measurement techniques should be interpreted with caution during OPCAB.
Arterial Pressure ; Cardiac Output ; Coronary Artery Bypass, Off-Pump ; Coronary Vessels ; Glycosaminoglycans ; Heart ; Hemodynamics ; Humans ; Prospective Studies ; Thoracic Surgery

Brain death results in adverse pathophysiologic effects in many brain-dead donors with cardiovascular instability. We experienced a brain-dead donor with continuous renal replacement therapy (CRRT) who was in a severe metabolic, electrolyte derangement and poor pulmonary function. The thirty-nine-year-old male patient with subarachnoid hemorrhage and intraventricular hemorrhage was admitted into the intensive care unit (ICU). After sudden cardiac arrest, he went into a coma state and was referred to as a potential organ donor. When he was transferred, his vital sign was unstable even under the high dose of inotropics and vasopressors. Even with aggressive treatment, the level of blood sugar was 454 mg/dl, serum K+ 7.1 mEq/L, lactate 5.33 mmol/L and PaO2/FiO2 60.3. We decided to start CRRT with the mode of continuous venovenous hemodiafiltration (CVVHDF). After 12 hours of CRRT, vital sign was maintained well without vasopressors, and blood sugar, serum potassium and lactate levels returned to 195 of PaO2/FiO2. Therefore, he was able to donate his two kidneys and his liver.
Blood Glucose ; Brain ; Brain Death ; Coma ; Death, Sudden, Cardiac ; Hemodiafiltration ; Hemorrhage ; Humans ; Intensive Care Units ; Kidney ; Lactic Acid ; Liver ; Male ; Potassium ; Renal Replacement Therapy ; Subarachnoid Hemorrhage ; Tissue Donors ; Vital Signs

Contralateral acute subdural hematomas that occur during removal of brain tumors under general anesthesia are extremely rare, and there are no reports of this developing during awake craniotomy for brain tumors. We report a case of a 12-year-old boy who complained of sudden and severe headache and nausea around the completion of removal of a glial tumor of the frontal lobe under awake anesthesia. Postoperative computerized tomography scan revealed the presence of contralateral acute minimal subdural hematoma. We suggest that during craniotomy with awake anesthesia for brain tumors, contralateral acute subdural hematoma may occur, even in the absence of brain bulging or changes in vital signs. Sudden intra-operative headache and nausea should be investigated by immediate postoperative computerized tomography scans to ascertain diagnosis.
Anesthesia ; Anesthesia, General ; Brain ; Brain Neoplasms ; Child ; Craniotomy ; Frontal Lobe ; Headache ; Hematoma, Subdural ; Hematoma, Subdural, Acute ; Humans ; Nausea ; Vital Signs

Contralateral acute subdural hematomas that occur during removal of brain tumors under general anesthesia are extremely rare, and there are no reports of this developing during awake craniotomy for brain tumors. We report a case of a 12-year-old boy who complained of sudden and severe headache and nausea around the completion of removal of a glial tumor of the frontal lobe under awake anesthesia. Postoperative computerized tomography scan revealed the presence of contralateral acute minimal subdural hematoma. We suggest that during craniotomy with awake anesthesia for brain tumors, contralateral acute subdural hematoma may occur, even in the absence of brain bulging or changes in vital signs. Sudden intra-operative headache and nausea should be investigated by immediate postoperative computerized tomography scans to ascertain diagnosis.
Anesthesia ; Anesthesia, General ; Brain ; Brain Neoplasms ; Child ; Craniotomy ; Frontal Lobe ; Headache ; Hematoma, Subdural ; Hematoma, Subdural, Acute ; Humans ; Nausea ; Vital Signs

Intraoperative transesophageal echocardiography (TEE) has become an important monitoring device for patients undergoing cardiac or noncardiac surgery. Complications associated with TEE are unusual, but the potential for TEE probe compression of the posterior vascular structures has been reported in pediatric patients. We present here a case of occlusion of the right subclavian artery in an adult patient with a vascular ring after insertion of a TEE probe.
Adult ; Echocardiography, Transesophageal ; Humans ; Subclavian Artery

BACKGROUND: Postoperative nausea and vomiting (PONV) is a common problem in patients undergoing thyroidectomy. In this study we evaluated the effects of prophylactic dolasetron and/or induction with propofol on PONV. METHODS: Two hundred three patients scheduled thyroidectomy under general anesthesia with sevoflurane were included and were randomly allocated to one of four groups. In control (group C) and dolasetron groups (group D), the patients received thiopental sodium 4-5 mg/kg intravenously for the induction of anesthesia, and the patients in group D received prophylactic intravenous dolasetron 210 microgram/kg. In propofol (group P) and dolasetron + propofol groups (group D + P), the patients received propofol 2 mg/kg intravenously for the induction of anesthesia, and the patients in group D + P received prophylactic intravenous dolasetron 210 microgram/kg. The incidence and severity of PONV, the need for rescue antiemetics, adverse events were assessed during 0 to 1 hour and 1 to 24 hours postoperatively. RESULTS: During the first 24 hours after anesthesia, the incidences of PONV and postoperative vomiting were significantly reduced in group D + P compared with group C (P < 0.05, respectively). There were no significant differences in postoperative nausea, need for rescue antiemetics, severity of PONV, and adverse events of antiemetics among the four groups. CONCLUSIONS: In patients with thyroidectomy, combination of prophylactic dolasetron administration and induction with propofol was found to reduce the incidence of PONV during the first 24 hours after anesthesia, compared with that of routine induction with thiopental sodium.
Anesthesia ; Anesthesia, General ; Antiemetics ; Humans ; Incidence ; Indoles ; Methyl Ethers ; Postoperative Nausea and Vomiting ; Propofol ; Quinolizines ; Thiopental ; Thyroidectomy