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The relationship between cardiac output and anesthetic drugs is important to anesthesiologists, since cardiac output determines the speed with which a drug infused into the bloodstream reaches its target and the intensity of the drug's effect. But rather than focus on how anesthetic drugs affect cardiac output, this narrative review focuses on how changes in cardiac output affect the pharmacokinetics and pharmacodynamics of general anesthetics during the three phases of anesthesia. At induction, an increase in cardiac output shortens both the onset time of propofol for hypnosis and the neuromuscular blocking effect of rapid-acting neuromuscular blockers, favoring the conditions for rapid sequence intubation. During maintenance, changes in cardiac output are followed by opposite changes in the drug plasma concentration of anesthetic drugs. Thus, an increase in cardiac output followed by a decrease in the plasma concentration of the anesthetic could expose the patient to a real risk of intraoperative awakening, which can be avoided by increasing the dose of hypnotic drugs. At emergence, an increase in cardiac output secondary to an increase in pC02 allows for a more rapid recovery from anesthesia. The pC02 can be increased by adding CO2 to the respiratory circuit, lowering the ventilatory rate, or placing the patient on partial rebreathing. Finally, the reversal action of sugammadex for rocuronium-induced neuromuscular block can be shortened by increasing the cardiac output.
La relación entre el gasto cardíaco y los fármacos anestésicos es importante para los anestesiólogos puesto que el gasto cardíaco determina la velocidad con la cual un medicamento que se infunde al torrente sanguíneo llega a su diana y la intensidad del efecto del agente. Pero en lugar de concentrarnos en cómo los fármacos anestésicos afectan el gasto cardíaco, esta revisión narrativa se enfoca en cómo los cambios en el gasto cardíaco afectan la farmacocinética y la farmacodinámica de los agentes anestésicos generales durante las tres fases de la anestesia. En el momento de la inducción, un incremento en el gasto cardíaco acorta tanto el tiempo de inicio del efecto del propofol para la hipnosis como el efecto del bloqueo neuromuscular causado por los bloqueadores neuromusculares de acción rápida, favoreciendo las condiciones para la intubación de secuencia rápida. Durante la fase de mantenimiento, los cambios en el gasto cardíaco vienen seguidos de cambios opuestos en la concentración plasmática del medicamento de los agentes anestésicos. Por lo tanto, un aumento del gasto cardíaco, seguido de una reducción en la concentración plasmática del anestésico, podría exponer al paciente a un riesgo real de despertar intraoperatorio, lo cual puede evitarse aumentando la dosis de los fármacos hipnóticos. En la educción, un aumento en el gasto cardíaco secundario al incremento en el pCO2 permite una recuperación más rápida de la anestesia. El pCO2 puede aumentar agregando CO2 al circuito de la respiración, reduciendo la tasa ventilatoria, o colocando al paciente en re-inhalación parcial. Finalmente, la acción de reversión de sugammadex en caso de bloqueo neuromuscular inducido por rocuronio, puede acortarse aumentando el gasto cardíaco.
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Objective:To explore the effect of regional nerve block anesthesia for elderly patients with traumatic tibia and fibula fractures.Methods:Ninety-three elderly patients with tibia and fibula fractures undergone surgical treatment were randomly divided into an observation group and a control group, with 47 and 46 patients, respectively, in each group.The control group received general anesthesia and the observation group received a regional nerve block.Results:There was no difference in operative time between the two groups[(42.2±5.4)min and(43.3±5.7)min, t=0.953, P=0.343].The time to recovery of consciousness[(11.2±2.6)min and(14.5±2.8)min, t=5.714, P<0.001]and the volume of intraoperative infusion[(415.6±27.5)ml/L and(686.6±36.3)ml/L, t=40.626, P<0.001]were lower and patients' blood pressure and respiratory rate were also lower at skin incision, fracture fixation, end of surgery and 30 min after surgery in the observation group than in the control group.The levels of Glu, IL-6 and COR were higher than those in the control group(all P<0.05).The incidence of complications was 2.13% in the observation group and 15.22% in the control group( χ2=5.07, P<0.05). Conclusions:Elderly patients with traumatic tibia and fibula fractures receive beneficial anesthetic effects with the regional nerve block technique, with stable hemodynamics, mild stress response and minor adverse reactions.
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Objective:To evaluate the dose-effect relationship of compound lidocaine hydrochloride for transverse abdominal plane-rectus abdominis sheath block (TAP-RSB) for postoperative analgesia in elderly patients undergoing laparoscopic radical colon cancer surgery with general anesthesia.Methods:Elderly patients of either sex, aged≥65 yr, with body mass index <30 kg/m 2, of American Society Anesthesiologists physical status Ⅰ-Ⅲ, undergoing elective laparoscopic radical colon cancer surgery with general anesthesia, were selected.After induction of general anesthesia, compound lidocaine hydrochloride was given under ultrasound guidance for bilateral TAP block (20 ml on each side) and for bilateral RSB (10 ml on each side), with the initial concentration of 0.4%.Each time the concentration increased/decreased in the next patient depending on whether or not the analgesia was effective.The ratio between the two successive concentrations was 1.00∶1.15.The analgesic effects were evaluated by the Numerical Rating Scale at 1 h intervals from the time of postoperative admission to the post-anesthesia care unit until 8 h after TAP-RSB (Numerical Rating Scale ≤ 3 was considered as effective analgesia). The probit method was used to calculate the half effective concentration (EC 50) and 95% effective concentration (EC 95) and 95% confidence interval of compound lidocaine hydrochloride. Results:The EC 50 and EC 95(95% confidence interval)of compound lidocaine hydrochloride for TAP-RSB were 0.289% (0.232%-0.352%) and 0.404% (0.345%-0.970%), respectively, when used for postoperative analgesia in elderly patients undergoing laparoscopic radical colon cancer surgery with general anesthesia. Conclusions:The EC 50 and EC 95 of compound lidocaine hydrochloride for TAP-RSB are 0.289% and 0.404%, respectively, when used for postoperative analgesia in elderly patients undergoing laparoscopic radical colon cancer surgery with general anesthesia.
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Analyze the level of consciousness by means of the Aldrete-Kroulik scale associated with the use of oxygen therapy at the Post-Anesthesia Care Unit (PACU). It is a prospective and comparative study, with quantitative analysis. It was conducted in a big Federal Public Hospital, located in Belo Horizonte city. The sample was consisted of 60 subjects, separated between groups using and do not using oxygen therapy, aged between 18 and 64 years old, submitted to elective surgery, surgical site in upper torso, under general anesthesia, and with the American Society Anesthesiologists (ASA) status I or II. The most part of the patients were female, with 50 years old or older, classified as ASA II, under total intravenous anesthesia, and length of time of anesthesia over 240 minutes. In the analysis of the level of consciousness related to the use of oxygen therapy, it is noteworthy that the p-value (0.069) is significant at the 15 minutes of permanence in the PACU. A large number of patients from the group that received supplemental oxygen therapy showed improvement in the level of consciousness at the 15 minutes of permanence in the PACU. Team work is necessary to prevent patient's complications in anesthetic recovery period.
Analyze the level of consciousness by means of the Aldrete-Kroulik scale associated with the use of oxygen therapy at the Post-Anesthesia Care Unit (PACU). It is a prospective and comparative study, with quantitative analysis. It was conducted in a big Federal Public Hospital, located in Belo Horizonte city. The sample was consisted of 60 subjects, separated between groups using and do not using oxygen therapy, aged between 18 and 64 years old, submitted to elective surgery, surgical site in upper torso, under general anesthesia, and with the American Society Anesthesiologists (ASA) status I or II. The most part of the patients were female, with 50 years old or older, classified as ASA II, under total intravenous anesthesia, and length of time of anesthesia over 240 minutes. In the analysis of the level of consciousness related to the use of oxygen therapy, it is noteworthy that the p-value (0.069) is significant at the 15 minutes of permanence in the PACU. A large number of patients from the group that received supplemental oxygen therapy showed improvement in the level of consciousness at the 15 minutes of permanence in the PACU. Team work is necessary to prevent patient's complications in anesthetic recovery period.
Subject(s)
Oxygen Inhalation Therapy , Anesthesia Recovery Period , Anesthetics, General , Consciousness Disorders , Delayed Emergence from AnesthesiaABSTRACT
General anesthetics were widely used in ophthalmology surgical and other surgical anesthesia, sedation and animal experiments. The current study found that anesthesia drugs such as ketamine, sevoflurane and propofol had a great influence on eyes. Elevated intraocular pressure was a risk factor for glaucoma occurrence and progress and it can change the intraocular structure, and damage the visual function. So in this paper, the effects of several kinds of general anesthetics commonly used were systematically described, in order to hold the attention of the clinicians and the researchers.
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Objective To investigate the role of NMDA receptors in central medial thalamus (CMT) in the unconscious?ness induced by general anesthesia. Methods A total of 60 rat models for microinfusion were assigned into 4 groups (n=15 for each group). After induction with propofol, 10 mmol/L (NMDA10 group), 20 mmol/L (NMDA 20 group) and 40 mmol/L (NMDA40 group) of NMDA and normal saline (group C) with equal volume were microinfused into CMT. The incidence of purposeful movement and recovery time of righting reflex were observed in each group respectively. Infusion sites were local?ized by histological method. Results When the microinfusion site localized within CMT, comparing with group C, the recov?ery time of righting reflex reduced notably in three NMDA groups (P0.05). Conclusion Microinfusion of NMDA agonist into CMT reverses propofol anesthesia, indicating that NMDA receptor in CMT may contribute to the propofol-induced unconsciousness.
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Association between postoperative nausea and vomiting (PONV) and micro-opioid receptor A118G single nucleotide polymorphism (SNP) is undefined and might underlie inconsistent results of studies on PONV occurrence in patients undergoing general anesthesia with the opioid, remifentanil. Four hundred and sixteen Korean women undergoing breast surgery with general anesthesia were randomized to receive remifentanil 10 ng/mL (plasma-site, Minto model) using a target-controlled infusion device and either propofol for total intravenous anesthesia (T group) or sevoflurane for inhalation anesthesia (I group) with bispectral index values maintained between 40 and 60. Blood specimens were collected after anesthesia induction for A118G SNP analysis. PONV and postoperative pain were evaluated. A118G SNP type distribution among Korean female adults studied was AG (n=195)>AA (n=158)>GG (n=63). Regardless of anesthetic technique, patients with GG types had lower PONV scale on arrival at postoperative care unit (PACU) (P=0.002), while T group showed lower PONV scale than I group up to 6 hr after PACU discharge in AA and AG types. No differences were apparent for postoperative pain among opioid receptor polymorphism. PONV occurrence differs according to opioid receptor polymorphism and anesthetic technique in patients undergoing general anesthesia with remifentanil.
Subject(s)
Adult , Female , Humans , Analgesics, Opioid/adverse effects , Anesthesia, General/adverse effects , Breast Diseases/surgery , Demography , Double-Blind Method , Methyl Ethers/adverse effects , Pain, Postoperative/drug therapy , Piperidines/adverse effects , Polymorphism, Single Nucleotide , Postoperative Nausea and Vomiting/etiology , Receptors, Opioid, mu/geneticsABSTRACT
Objective To compare the pressor responses to ephedrine during general anesthesia with different drugs.Methods Sixty ASA physical status Ⅰ or Ⅱ patients,scheduled for elective gastrointestinal tumor resection under general anesthesia,aged 20-64 yr,weighing 45-90 kg,were included in this study.The patients were randomized to receive dexmedetomidine + remifentanil + sevoflurane (group Ⅰ,n =20),propofol + remifentanil + sevoflurane (group Ⅱ,n =20),or dexmedetomidine + propofol + remifentanil + sevoflurane (group Ⅲ,n =20) to maintain the depth of anesthesia.Ephedrine 0.1 mg/kg was injected intravenously when the systolic blood pressure (SBP) was decreased to about 90 mm Hg during anesthesia.Blood pressure was monitored and recorded at 1-min intervals for 10 min after the injection.The onset time (TSBP,TDBP,TMAP) for ephedrine to raise the SBP,diastolic blood pressure (DBP) and mean arterial pressure (MAP) and the maximal amplitude (△SBP,△DBP,△MAP) were also recorded.Results Compared with Ⅱ group,TSBP,TDBP and TMAP were significantly shortened,and △SBP,△DBP and △MAP were increased in Ⅰ and Ⅲ groups (P ＜ 0.05).Conclusion Compared with propofol + remifentanil + sevoflurane combined anesthesia,dexmedetomidine + remifentanil + sevoflurane combined anesthesia and dexmedetomidine + propofol + remifentanil + sevoflurane combined anesthesia augment the pressor responses to ephedrine in patients.
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Objective To investigate the impact of different anesthesia methods on intraoperative and postoperative patients un-dergoing laparoscopic rectal cancer surgery and to explore the ideal anesthetic method for laparoscopic rectal cancer surgery .Meth-ods 40 cases of laparoscopic resection for rectal cancer ,ASAⅠ-Ⅱ grade ,were selected and randomly divided into two groups .The group A (20 cases) was performed general anesthesia combined with epidural anesthesia and the B group (20 cases) was performed systemic anesthesia .The intraoperative hemodynamics ,respiratory function ,awaking time and awaking quality evaluation were ob-served .Results The airway pressure(Paw ) and PETCO2 in the two groups were increased .The intraoperative hemodynamics in the group A was more stable than those in the group B .The awaking time and awaking quality in the group A were superior to those in the B group .Conclusion Compared with simple general anesthesia ,general anesthesia combined with epidural anesthesia for laparo-scopic rectal cancer surgery has more stable vital signs and better awaking quality ,whoich is an ideal anesthetic method for laparo-scopic rectal cancer surgery .
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Objective To investigate the effects of different anesthesia methods on oxidative stress in elderly patients undergoing neurosurgery.Methods Totally 60 patients undergoing neurosurgery were randomly divided into 3 groups:propofol group,isoflurane group and sevoflurane group (n-20 each group),heart rate(HR) and mean artery pressure(MAP) in all patients were recorded at the time points of pre anesthesia (T0),incision of skin (T1),incision of dura (T2),end of operation (T3).The activity of superoxide dismuase (SOD),catalase (CAT),and glutathione peroxidase (GSH-Px) were measured at the time of T0,6 h (T4),24 h (T5),48 h (T6),72 h (T7)after operation.The efficacy of anesthesia was evaluated by Glasgow Outcome Score (GOS) at 3 months after operation.Results The activity of SOD,CAT and GSH Px in 3 groups were lower at T5and T6 than at T0 (P＜0.05).The SOD activity at T4,T5,T5and TTwere higher in propofol group [(87.2±11.8) U/ml,(75.1±12.4) U/ml,(84.6±9.3) U/ml,(92.5±12.5) U/ml,respectively]than in isoflurane group [(75.0±12.2) U/ml,(63.8±8.9) U/ml,(70.3±9.0) U/ml,(82.5±13.5) U/ml,respectively] and in sevoflurane group [(79.4±10.4) U/ml,(68.7±10.5) U/ml,(72.0±10.9) U/ml,(85.17±8.41) U/ml,respectively] (all P＜0.05).The CAT activity at T5 was higher in propofol group [(66.59±7.21) U/ml] than in isaflurane group [(51.58±8.19) U/ml] and in sevoflurane group [(58.49±7.27) U/ml] (both P＜0.05).The GSH-Px activity was higher at T4,T5and T6 in group propofol[(159.2 ± 20.8) U,(140.7 ± 16.2) U,(152.3 ± 19.1) U,respectively] than in isoflurane group [(129.4±17.9) U,(108.3±15.9) U,(118.4±14.1) U,respectively] and in sevoflurane group [(140.1±15.8) U,(125.2± 17.1) U,(137.9±10.7) U,respectively] (all P＜0.05).The outcome of neurosurgery had no significant differences among the 3 groups (P＞0.05).Conclusions Propofol has a better effect on oxidative stress than isoflurane and sevoflurane in elderly patients undergoing neurosurgery.
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Objective To observe the clinical efficacy and safety of close-loop muscle relaxant injcction system (CLMRIS) combined with auditory evoked potentials index for monitoring in elderly patients during general anesthesia.Methods A total of 100 patients undergong abdominal operation with ASA Ⅰ-Ⅱ anesthesia in our hospital from February 2012 to October 2012 were selected.Patients were randomly divided into 2 groups:the traditional group (n=50) and the CLMRIS group (n=50).The traditional group was anaesthetized according to clinical experience,and the CLMRIS group was used with the muscle relaxant guided by the close-loop muscle relaxant injection system.The auditory evoked potential (AEP) index and the life index were observed,and the dose of muscle relaxant,the time of consciousness recovery,dynamic response rate during operation and the adverse reaction were recorded at the time points at entering the operating room,induction of anesthesia,tracheal intubation,incision,into the abdominal,exploration,closing abdomen,skin suture,consciousness recovery,tracheal extubation,out of room (T0-T10).Results The vital signs in all patients were stable.The dynamic response rate during operation was lower in the CLMRIS group than in the traditional group at each time points of T8-T10 (all P＜0.05).There was no increase in mean artery pressure (MAP) and heart rate in groups at the time points of T0-T1,T8-T10 (all P＞0.05).The time of tracheal intubation,tracheal extubation and consciousness recovery were shorter in the CLMRIS group than in the traditional group [(268±30.4) min vs.(172±23.7) min,(14±6.4) min us.(18±7.9) min,(8.8±2.9) min vs.(12.2±4.6) min,respectively,t=3.277,6.341,3.346,all P＜0.05].There were no significant differences in AEP index between groups at the time of T0 (P＞0.05),but at the time of T1,the AEP index was lower in CLMRIS group than in the traditional group (P＜0.05).Conclusions The application of close loop muscle relaxant injection system can improve the safety of general anesthesia in the elderly and reduce the incidence of postoperative residual paralysis.The CLMRIS combined with the auditory evoked potential for monitoring depth of anesthesia can prevent and reduce the incidence of intraoperative awareness,has a strong controllability in general anesthesia with smooth induction,and can reduce the dose of anesthetic drugs to achieve the best anesthetic effect.
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Objective To observe the clinical effects of sufentanil combined with sevoflurane for anesthesia induction in the elderly.Methods A total of 84 patients undergoing elective laparoscopic were randomly divided into 4 groups by dose of Sufentanil (21 cases,each):0.25,0.50,0.75 and 1.00 μg/kg sufentanil.Mean arterial pressure (MAP)and heart rate (HR)were measured at baseline (To),immediately before intubation(T1),immediately,1,3 and 5 min after intubation(T2-5).Intubation scores were also recorded.Results The intubation scores including visual analogue score (VAS) and Ramsay score at 10 min,30 min and 60 min after tube drawing were as the following sequence:1.0 μg/kg ＞ 0.75 μg/kg ＞0.5 μg/kg ＞ 0.25 μg/kg sufentanil (F =5.78.P＜ 0.05).Compared with T0,MAP and HR decreased in each group at T1,while increased at T2 in group A (P＜0.05).As compared with T0,MAP was decreased and HR was slower at T1 in the 4 groups (F=34.99,P＜0.05),but MAP level was increased in 0.25 μg/kg sufentanil group at T2 (F=12.48,P＜0.05).Compared with group of 0.25 μg/kg sufentanil,MAP was reduced in 0.75 μg/kg and 1.00 μg/kg groups at T4 andT5 (F =6.98,6.25,P＜0.05).MAP was also lower in 0.75μg/kg and 1.00μg/kg groups than in 0.50 μg/kg sufentanil group at T2-T5(F=7.08,20.56,P＜0.05).Conclusions Sufentanil of 0.25 0.50 μg/kg combined with sevoflurane can provide excellent intubating conditions and stable hemodynamics during anesthesia induction in patients undergoing gynecologic surgery.
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ObjectiveTo investigate the effects of acupuncture on neuromuscular block of vecuronium and analgesia under general anesthesia.MethodsNinety ASA Ⅰ or Ⅱ patients,aged 29-80 yr,weighing 50-80kg,scheduled for laparoscopic chotecystectomy,were randomly divided into 3 groups (n =30 each):acupuncture at acupoints combined with general anesthesia group (group A),acupuncture at non-acupoints combined with general anesthesia group (group B) and general anesthesia group (group C).Bilateral Hegu (LI4),Neiguan (PC6),Zusanli (ST36),yanglingquan (GB34),and Quchi (LI11) acupoints were selected in group A.In group B,the points adopted were the midpoints between the meridians in which the acupoints were selected in group A and the adjacent meridians on the lateral side,at the level of selected meridian points correspondingly.Electric stimulation was started from 15-30 min before anesthesia induction and continued until the end of operation.Anesthesia was induced with iv injection of fentanyl,propofol and vecuronium and maintained with intermittent iv boluses of fentanyl and vecuronium.All the patients received patient-controlled intravenous analgesia after operation.The effect time,onset time,clinical duration and recovery index of vecuronium,consumption of anesthetics during operation,and consumption of fentanyl for postoperative analgesia and postoperative adverse reactions were recorded.Results Compared with group C,the elinical duration was significantly prolonged,the consumption of anesthetics during operation and consumption of fentanyl for postoperative analgesia were significantly reduced,and the incidence of nausea was significantly decreased ( P ＜ 0.05 ),while no significant changed was found in the effect time,onset time,and recovery index in group A ( P ＞ 0.05).Compared with group B,the amount of fentanyl consumed during and after operation was significantly reduced in group A ( P ＜ 0.05 ).ConclusionAcupuncture can prolong the clinical duration of vecuronium,and enhance the analgesic efficacy during and after operation under general anesthesia.
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Objective To discuss the significance ofbispectral index (BIS) monitoring during the patients after general anesthesia while leaving the post-anesthetic intensive care unit (PAICU). Methods Seventy-five cases after general anesthesia were selected. When they were sent out of the PAICU, recorded their BIS. Results Twenty-one cases with BIS 90 - 100,48 cases with BIS 80 - 89 in slight calm and hypnosis,5 cases with BIS 70 - 79, and 1 case with BIS 50 - 60. Conclusions Without BIS monitoring,when sent out of the PAICU,most patients after general anesthesia are gently sedated and without too much risk. But still some patients are deeply sedated. BIS monitoring provides a nice reference for the patients while leaving the PAICU.
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The formalin test is a model of injury-produced inflammatory pain. Anesthetics, in clinically relevant concentrations, affect neutrophils and immune suppression. This study was to determine whether halothane reliably inhibits inflammatory reaction and formalin induced pain behavior or does not. Rats were exposed to 100% oxygen (control) or halothane, respectively for 30 min and then 24 hr later five percent formalin test was assessed. The base values of the paw's diameter were obtained earlier, and then formalin induced edema was assessed by measuring diameters of the injected paws at 5 min, 1 hr, 4 hr and 24 hr after the injection. Nociceptive behavior was quantified by counting the number of times with the paw flinched at 5 min intervals for 60 min. The diameters of edema in the halothane group lessened more than those in the oxygen group at 1 and 24 hr in each following of the injection (p<0.05). The rats pre-administered with oxygen or halothane were similar appearances in nociceptive behaviors. It suggests that halothane anesthesia might inhibit slightly the inflammatory reaction with the formalin-induced edema but might not inhibit the formalin-induced pain behavior in the event of pre-administration halothane 24 hr earlier before the formalin test of rat.