OBJECTIVETo investigate the effect of propofol on brain regions at different sedation levels and the association between changes in brain region activity and loss of consciousness using blood oxygen level-dependent functional magnetic resonance imaging (BOLD-fMRI) and bispectral index (BIS) monitoring.

METHODSForty-eight participants were enrolled at Peking Union Medical College Hospital from October 2011 to March 2012 and randomly assigned to a mild or a deep sedation group using computer- generated random numbers. Preliminary tests were performed a week prior to scanning to determine target effect site concentrations based on BIS and concomitant Observer's Assessment of Alertness/Sedation scores while under propofol. Within one week of the preliminary tests where propofol dose-response was established, BOLD-fMRI was conducted to examine brain activation with the subject awake, and with propofol infusion at the sedation level.

RESULTSMild propofol sedation inhibited left inferior parietal lobe activation. Deep sedation inhibited activation of the left insula, left superior temporal gyrus, and right middle temporal gyrus. Compared with mild sedation, deep propofol sedation inhibited activation of the left thalamus, precentral gyrus, anterior cingulate, and right basal nuclei.

CONCLUSIONMild and deep propofol sedation are associated with inhibition of different brain regions, possibly explaining differences in the respective loss of consciousness processes.

Adult ; Brain ; drug effects ; Consciousness Monitors ; Deep Sedation ; Dose-Response Relationship, Drug ; Humans ; Hypnotics and Sedatives ; pharmacology ; Male ; Propofol ; pharmacology

OBJECTIVETo compare the efficacy of ondansetron and granisetron in the prevention of postoperative nausea and vomiting (PONV) in high-risk patients.

METHODSTotally 200 patients with three key risk factors for PONV (female, non-smoking and postoperative opioid use) were equally randomized into ondansetron group and granisetron group. Ondansetron (4 mg) or granisetron (3 mg) was intravenously administered upon the completion of surgery. The episodes of nausea and vomiting were observed for 24 hours after surgery.

RESULTSA significantly greater proportion of patients in granisetron group achieved a complete response (i.e., no PONV or rescue medication) during the first 24 hours postoperatively versus those in ondansetron group (62.6% vs. 46.9%, respectively; P=0.048). There were no significant differences in terms of postoperative nausea incidences (42.9% vs. 34.3%, respectively), postoperative vomiting incidences (25.5% vs. 20.2%, respectively) and postoperative rescue anti-emetics incidences (19.4% vs. 15.2%, respectively) (P>0.05).

CONCLUSIONGranisetron is more effective than ondansetron in preventing PONV in high-risk patients during the first 24 hours postoperatively.

Adolescent ; Adult ; Aged ; Antiemetics ; therapeutic use ; Double-Blind Method ; Female ; Granisetron ; therapeutic use ; Humans ; Male ; Middle Aged ; Ondansetron ; therapeutic use ; Postoperative Nausea and Vomiting ; prevention & control ; Treatment Outcome ; Young Adult

In recent years increased studies on the relationship between addictive drugs abuse and infectious diseases such as acquired immunodeficiency syndrome (AIDS) have shown that these drugs, including heroin, marijuana and cocaine, not only alter the abusers' neuropsychological and pathophysiological responses, but also impair their immune functions. The possible mechanisms may include the direct effect on immune cells or an indirect method ( e. g., stimulation of the hypothalamus-pituitary-adrenal axis). The correlation between intravenous drug users (IVDUs) and human immunodeficiency virus infections has led to the proposal that the immunomodulation mediated by additive drugs is a major factor contributing to the progression of AIDS in IVDUs. Immunosuppression caused by drug abuse may increase the susceptibility to opportunistic infections, while drug abusers' lifestyles also increase exposure risk to infectious pathogens. In summary, increased infection risks and drug-mediated immunomodulation increase drug abusers' susceptibility to infectious pathogens.
Disease Susceptibility ; Humans ; Immune System ; drug effects ; physiology ; Infection ; etiology ; Narcotics ; adverse effects ; Substance Abuse, Intravenous ; complications

BACKGROUNDPerioperative disorder of magnesium, an important cation in the human body, may affect clinical anesthesia. The pharmacological data of propofol use, which is popularly used in the anesthesiology department and intensive care unit, is incomplete in Chinese patients. This study aimed to assess the effect of magnesium sulfate on the calculated plasma medial effective concentration (Cp50cal) of propofol at loss of response to command in Chinese females.

METHODSFifty patients undergoing gynecological laparoscopic surgery were randomly divided into the control group and the magnesium group. Before induction, magnesium sulfate (30 mg/kg) or placebo (equal volume of 0.9% saline) was given to patients in the magnesium group or the control group, respectively. Propofol was infused using a target-controlled infusion system, with a target concentration for each patient decided by up-and-down sequential allocation. After the equilibration between target plasma concentration and effective-site concentration, the state of consciousness was assessed. For determination of serum magnesium and calcium concentration, blood samples were taken before induction, after induction and at the end of surgery.

RESULTSThe Cp50cal was 2.52 µg/ml (2.47 - 2.57 µg/ml) for patients in the control group, and 2.46 µg/ml (2.41 - 2.51 µg/ml) for those in the magnesium group. A significant reduction of Cp50cal was observed (P = 0.021). There was a significant difference between the serum magnesium concentrations after induction and at the end of the surgery (P < 0.05). In the magnesium group, there was a trend toward decreasing after surgery, while in the control group, Cp50cal decreased significantly (P < 0.01).

CONCLUSIONSCp50cal of propofol at loss of response to command was 2.52 µg/ml (2.47 - 2.57 µg/ml) for Chinese female adults in this study. Infusion of 30 mg/kg magnesium sulfate may reduce the Cp50cal of propofol at loss of consciousness, which implies that magnesium may enhance the pharmacological effects of propofol.

Adolescent ; Adult ; Anesthetics ; therapeutic use ; Female ; Humans ; Magnesium Sulfate ; therapeutic use ; Middle Aged ; Propofol ; blood ; pharmacokinetics ; therapeutic use ; Unconsciousness ; chemically induced ; Young Adult

OBJECTIVETo investigate the relationship between the plasma adrenomedullin (ADM) levels and the extent of chronic cor-pulmonale and its underlying diseases, and explore the role of ADM in these diseases.

METHODSTotally 26 patients with chronic bronchitis, chronic bronchitis accompanied with obstructive pneumonectasia or chronic cor-pulmonale were included respectively as clinical test group T1, T2 and T3; 26 normal people and 14 patients with pneumonia were chosen as control groups (group C1 and C2). Plasma concentration of ADM in every selected individual had been measured with specific radioimmunoassay.

RESULTSLevels of plasma ADM in T3 were significantly higher than those in T2, and T2 than T1, C1 and C2 (P < 0.05), but there were no obvious difference between T1 and C1, between T1 and C2 (P > 0.05).

CONCLUSIONSPlasma ADM levels can reflect the severity of the above series of diseases.

Adrenomedullin ; Aged ; Bronchitis, Chronic ; blood ; Female ; Humans ; Male ; Middle Aged ; Peptides ; blood ; Pulmonary Disease, Chronic Obstructive ; blood ; Pulmonary Heart Disease ; blood ; Severity of Illness Index

OBJECTIVETo compare the efficacy of different 5-hydroxytryptamine 3 receptor antagonists in the prevention of postoperative nausea and vomiting (PONV) in patients undergoing general anesthesia.

METHODSTotally 360 patients, American Society of Anesthesiologists (ASA) grade I - II, aged 18-75 years, and having received elective operation with endotracheal intubation general anesthesia, were randomly divided into three double-blind groups: ondansetron group, tropisetron group, and granisetron group, with 120 patients in each group. Before anesthesia induction, patients were intravenously given ondansetron (4 mg), tropisetron (5 mg), or granisetron (3 mg), respectively. The episodes of nausea and vomiting were recorded for 24 hours after operation.

RESULTSNo significant differences were observed in the terms of complete inhibition rate of PONV among ondansetron group (70.0%), tropisetron group (68.6%), and granisetron group (72.9%) within 24 hours postoperatively (P >0.05), and so did postoperative nausea incidences (22.5%, 25.4%, and 20.3%, respectively), and postoperative vomiting incidences (10.0%, 13.6%, and 8.5%, respectively) (P > 0.05). No remarked antiemetic-related adverse effects were observed within 24 hours postoperatively.

CONCLUSIONIntravenous ondansetron (4 mg), tropisetron (5 mg), or granisetron (3 mg) before anesthesia induction can prevent PONV with similar efficacy and safety.

Adolescent ; Adult ; Aged ; Anesthesia, General ; adverse effects ; Antiemetics ; therapeutic use ; Double-Blind Method ; Female ; Granisetron ; therapeutic use ; Humans ; Indoles ; therapeutic use ; Male ; Middle Aged ; Ondansetron ; therapeutic use ; Postoperative Nausea and Vomiting ; etiology ; prevention & control ; Young Adult

OBJECTIVETo investigate the effect of subanaesthetic dose of ketamine on mechanical stimulus on brain regions.

METHODSTotally 13 healthy male volunteers were enrolled in this study, in whom 0 and 100 ng/ml ketamine were administrated by target controlled infusion system in pilot study. After von Frey filaments (vFFs) 300 g were used as mechanical stimuli, Visual Analogue Scale scores were evaluated. Functional magnetic resonance imaging (fMRI)was taken 1 week after pilot study at the following sequences: structure imaging + functional imaging (stimulus sequence with 300 g vFFs, ketamine sequence); stimulus sequence = 6×(20s on + 20s off), with target concentration of ketamine at 0,100 ng/ml.fMRI result was processed by SPM2 and Metlab 7.01 software package.

RESULTSPosterior cerebellum lobe and corpus callosum were inhibited at 100 ng/ml under vFFs stimulus, whereas cingulate gyrus, middle frontal gyrus, inferior parietal lobule, occipital lobe, and posterior cerebellum lobe were activated at 100 ng/ml under vFFs stimulus.

CONCLUSIONSKetamine 100 ng/ml exerts its effect on pain related brain regions. It can both activate and inhibit these brain regions, with the activating effect being the primary effect.

Adult ; Analgesics ; administration & dosage ; pharmacology ; Brain ; drug effects ; physiopathology ; Humans ; Ketamine ; administration & dosage ; pharmacology ; Magnetic Resonance Imaging ; Male ; Pain ; physiopathology ; Pilot Projects

Severe tracheal stenosis can not only cause critical medical problems such as severe shortness of breath, hypoxia, and even orthopnea, but also impose overwhelming challenges on the physicians, particularly the anesthesiologist. Life-threatening airway obstruction can make the patient's gas exchange extremely difficult.Though several options could be offered regarding the treatment of tracheal stenosis, normally, tracheal resection and following reconstruction is the first choice for severe airway stenosis. Successful surgical intervention relies on the close communication and cooperation between surgeons and anesthesiologists. In these cases, airway management is the top issue for the anesthesiologist, and the level of difficulty varies with stenosis location, severity of stenosis, and surgical technique. Extracorporeal membrane oxygenation (ECMO), or cardiopulmonary bypass (CPB), is rarely utilized for the surgery, but for those impossible airways due to nearly complete tracheal obstruction, ECMO or CPB could be the final choice for anesthesiologists. Here we report a case of successful urgent airway management for tracheal resection and reconstruction assisted by temporary CPB.
Cardiopulmonary Bypass ; Emergencies ; Female ; Humans ; Middle Aged ; Reconstructive Surgical Procedures ; methods ; Trachea ; surgery

OBJECTIVETo determine the effects of atracurium pretreatment with magnesium on speed of onset, duration, and recovery of neuromuscular block.

METHODSThirty patients who were undergoing elective gynecologic laparoscopic examination and treatments under general anesthesia were randomized into magnesium group (n = 15) and control group (n = 15). Before induction of general anesthesia, patients in magnesium group intravenously received MgSO4 30 mg/kg in saline within 5 minutes, and patients in control group received the same volume of saline without MgSO4. In both groups, the train-of-four (TOF) responses to stimuli of the ulnar nerve were measured at intervals of 12 seconds. Anesthesia was induced with Fentanyl and Propofol through target controlled infusion (TCI), and tracheal intubation was performed with 0.5 mg/kg atracurium after stabilization of the electromyography recording. The onset time of muscle relaxation, clinical duration of action, recovery index, and recovery time were recorded. To determine serum magnesium and calcium levels, blood samples were collected before MgSO4/saline infusion and at the end of operation. Haemodynamic changes and other responses during induction were also recorded.

RESULTSThe onset time from the end of injection to maximum neuromuscular blockade was significantly shorter in magnesium group than in control group (P < 0.01). Duration of relaxant action, recovery index, and recovery time in magnesium group were significantly prolonged than in control group (P < 0.01). Serum magnesium level significantly decreased after management (P < 0.01), and there was also a decrease trend in magnesium group. No change of serum calcium levels in both groups was observed. No adverse event was reported.

CONCLUSIONPrior administration of magnesium sulphate can increase the onset speed of atracurium and prolong the duration of atracurium-induced neuromuscular blockade.

Adolescent ; Adult ; Anesthesia Recovery Period ; Anesthesia, General ; Atracurium ; pharmacology ; Drug Synergism ; Female ; Humans ; Magnesium Sulfate ; pharmacology ; Middle Aged ; Neuromuscular Blockade ; Neuromuscular Junction ; drug effects ; Neuromuscular Nondepolarizing Agents ; pharmacology ; Time Factors ; Young Adult

OBJECTIVETo study the psychedelic effects in healthy volunteers when given subanesthetic dose of ketamine.

METHODSThirteen male healthy volunteers aged 24-39 years were enrolled. All subjects received subanesthetic doses of ketamine using target control infusion. A stepwise series of target plasma concentrations (0, 100, 200, and 300 ng/ml) were maintained for 20 minutes each. Visual analogue scale (VAS) of mechanical pain by von Frey hair was evaluated, and then the volunteers completed a VAS rating of 13 symptom scales. Pictures were shown to them at the same time. Heart rate, mean blood pressure, and SpO2 were monitored throughout the infusion.

RESULTSDuring the process of analgesia, ketamine produced dose-related analgesic effects. With the increase of ketamine dose, some psychedelic effects became more obvious and the memory impairment became worse stepwisely.

CONCLUSIONTarget control infusion of subanesthetic doses of ketamine produce obvious psychedelic effects in healthy volunteers.

Adult ; Anesthetics, Dissociative ; administration & dosage ; adverse effects ; pharmacology ; Dose-Response Relationship, Drug ; Hallucinations ; chemically induced ; Humans ; Ketamine ; administration & dosage ; adverse effects ; pharmacology ; Male