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Objective To investigate the effect of dexmedetomidine on cognitive dysfunction after offpump coronary artery bypass grafting in patients.Methods Fifty-eight ASA physical status Ⅱt or Ⅲ patients,aged 51-63 yr,weighing 52-83 kg,undergoing off-pump coronary artery bypass grafting,were randomly divided into 2 groups (n =29 each):control group (group C) and dexmedetomidine group (group D).Anesthesia was induced with midazolam,etomidate,sufentanil and pipecuronium.The patients were thracheal intubated and mechanically ventilated.Anesthesia was maintained with propofol,sufentanil,isoflurane and pipecuronium.A loading dose of dexmedetomidine 1 μg/kg was infused over 15 min after tracheal intubation,followed by dexmedetomidine infusion at 0.5 μg· kg-1 · h-1 until the end of operation in group D,while the equal volume of normal saline was infused in group C.Cognitive function was assessed by Mini-Mental State Examination (MMSE) at 24 h before operation and 24,48 and 72 h after operation.The development of postoperative cognitive dysfunction was recorded within 72 h after operation.The consumption of sufentanil and extubation time after extubation was recorded.Results Compared with group C,MMSE scores at 24 and 48 h after operation were significantly increased and the incidence of postoperative cognitive dysfunction within 72 h after operation was decreased (P ＜ 0.05),and no significant change was found in the consumption of sufentanil and extubation time in group C (P ＞ 0.05).Conclusion Dexmedetomidine can decrease the development of postoperative cognitive dysfunction after off-pump coronary artery bypass grafting in patients.
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Objective To determine the proper dosage of fentanyl for open heart surgery performed under cardiopulmonary bypass (CPB) without aortic cross-clamping and cardioplegia.Methods Twenty-seven ASA Ⅰ -H patients (10 male, 17 female) with fairly good cardiac function (NYHA Ⅰ - Ⅱ) scheduled for surgical repair of atrioseptal defect ( ASD) or ventricular septal defect (VSD) or mitral valve replacement (MVR) were studied. Age ranged from 18 to 44 years and body weight from 35 to 58 kg. The patients were randomly divided into three fentanyl dosage groups: group Ⅰ 10?kg ; group II 30 ?g kg-1 and group Ⅲ 50 ?g kg-1. Premedication consisted of intramuscular pethidine 1-2 mg kg-1 and scopolamine 0.05-0.06 mg kg-1 . Anesthesia was induced with midazolam 0.2 mg kg-1 and fentanyl 5 ?g kg-1 . Tracheal intubation was facilitated with vecuronium 0.15 mg g-1 . The patients were mechanically ventilated (Vr 8-10 ml kg-1 ,F 10-12 bpm,FiO2 100% ). The rest of the total dose of fentanyl (5 ?g kg-1 in group I , 25 ?g kg-1 in group II , 45 ?g kg-1 in group III) was infused after induction of anesthesia until the initiation of CPB, supplemented with inhalation of 0.6 % isoflurane. During CPB propofol was infused at 5 mg kg-1 h-1 . after discontinuation of CPB, again 0.6% isoflurane was inhaled until the end of surgery. Vecuronium 0.05 mg kg was given every 25-30 min during operation. EGG, HR, BP, CVP, SpO2, PET CO2 and body temperature (naso-pharyngeal and rectal) were continuously monitored during operation. Arterial blood samples were obtained before anesthesia (T0), 5 min after tracheal intubation (T, ) , immediately after thoracotomy (T2) , immediately before CPB (T3), 15 min after CPB was initiated (T4) , 10 min after termination of CPB (T5) and 5 min after chest was closed (T6) for blood gas analyses and determination of blood electrolytes and acid-base balance and blood concentrations of glucose, ACTH, angiotensin Ⅱ (A- Ⅱ ) and cortisol. Time of emergence from anesthesia and extubation were recorded.Results The demographic data, including age and body weight, CPB time and duration of surgery were comparable among the three groups. There were no significant changes in SpO2 , PETCO2 , body temperature, blood gases and electrolytes during operation in the three groups. MAP decreased significantly during CPB. The blood glucose, ACTH, A- Ⅱ and cortisol concentrations increased significantly during and after CPB as compared with the preanesthetic baseline (T0 ) ( P
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Objective To evaluate the effect of CPB with or without cardioplegia on hemodynamics and myocardial function. Methods Thirty NYHA class III patients undergoing mitral valve replacement were randomly divided into three groups of ten each: group Ⅰ received no blood cardioplegia; group Ⅱ received tepid blood cardioplegia solution and group Ⅲ received cold blood cardioplegia solution. The patients were premedicated with pethidine 50mg and scopolamine 0.3mg. Swan-Ganz catheter was inserted via right interval jugular vein into pulmonary artery and radial artery was cannulated under local anesthesia before anesthesia. Anesthesia was induced with midazolam 0.05-0.01 mg.kg-1, fentanyl 15-20?g. kg-1 and pancuronium 0.12mg.kg-1 and maintained with fentanyl, midazolam and pancuromium. Patients in group Ⅰ received no cardioplegic solution. Ascending aorta was not cross-clamped. Body temperature was reduced to 32℃-33 ℃ (naso-pharyngeal T) . The empty heart was beating at 40-60 bmp. In group D and Ⅲ cardioplegic solution (modified St. Thomas solution) was added to blood from oxygenator (in the proportion of 1:4).In group Ⅱ body temperature was reduced to 32℃-33℃.Tepid (32℃ ) hyperkalemia blood cardioplegic solution was infused at 200-250ml.min-1 after ascending aorta was cross-clamped. After cardioplegic arrest hypokalemic blood cardioplegia solution was infused. In group Ⅲ body temperature was reduced to 28℃-29℃. Cold (8℃) hyperkalemic blood cardioplegic solution was infused at 200-250ml. min-1, after ascending aorta was cross-clamped. After cardioplegia arrest cold hypokalemic blood cardioplegia solution was infused every 20 min. Hemodynamic parameters (MAP, MPAP, CO, CI, SVRI, PVRI, LVSWI and RVSWI) were recorded before anesthesia (T0), before CPB (T1), 10, 30, 60 min after termination of CPB (T2-T4 ) and at the end of surgery (T5 ) . Results Demographic data including age, gender, body weight and body surface area were comparable between the three groups. CI in group 1 and Ⅱ was significantly higher at T2 -T5 than that in group Ⅲ . SVRI after CPB in group Ⅰ was significantly lower than that in group Ⅲ . Conclusion The myocardial function after CPB without cardioplegia is better than that after CPB with cold cardioplegia, but is not significantly different from that after CPB with tepid blood cardioplegia.
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Objective To evaluate the feasibility of catheterization of subclavian vein via supra-clavicular puncture in children less than six years of age, in comparison with subclavian vein catheterization via infraclavicular puncture and cannulation of internal jugular vein (IJV) from a high medial approach. Methods One hundred and eighty children (104 male, 76 female) aged 15 d-6 yr, undergoing major surgery were randomly divided into 3 equal groups of 60 patients: group I subclavian vein catheterization via supra-clavicular puncture; group Ⅱ subclavian vein catheterization via infra-clavicular puncture and group Ⅲ IJV catheterization from a high medial approach. (1) The overall success rate of puncture, (2) the success rate of puncture at first attempt, (3) the success rate of cannulation, (4) the duration from beginning of puncture to aspiration of blood, (5) the duration from the beginning of puncture to successful cannulation and (6) complication were recorded. Chest X-ray was taken in 30 patients in group I for confirmation of the position of catheter in subclavian vein. Results (1) The overall success rate of puncture was 100% and the success rate of puncture at first attempt was 86.67% in group I significantly higher than those in group Ⅱ (91.96% and 51.67%) and group Ⅲ (93.33% and 58.33%) (P
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ve To investigate the effects of acute normovolemic hemodilution on cardiac troponin I (CTnl) and myocardial enzyme. Methods Twenty-nine ASA I-II patients undergoing hepatectomy or bilateral hip replacement were randomly divided into two groups: hemodilution group (H , n=15) and control group (C, n=14) . The patients were premedicated with diazepam and scopolamine. Left radial artery was cannulated for intra-arterial pressure monitoring and the letting of blood. Right internal jugular vein was cannulated for fluid administration and CVP monitoring. Anesthesia was induced with midazolam 0.15-0.30mg?kg-1 , fentanyl 4?g?kg-1 and vecuronium 0.08-0.1mg?kg-1 and maintained with infusion of midazolam (0.03-0.10 mg?kg-1?h-1), fentanyl (0.15-2.0?g?kg-1?h-1) and vecuronium (0.5-1.0?g?kg-1?min-1). After tracheal intubation the patients were mechanically ventilated with 100% O2 and PETCO2 was maintained at 35-45 mmHg. 15 min after induction of anesthesia hemodilution was started. Blood was withdrawn from radial artery and collected until Hct was reduced to 25%-28% . Ringer's lactate solution and hydroxyethyl starch (HES 6%) were simultaneously infused to maintain blood volume. Blood samples were taken before anesthesia, before blood transfusion, 4h after surgery and on the 1st postoperative day for determination of blood CTnI, CK and CK-MB activities. Results The demographic data including age and body weight were not significantly different between the two groups. Prior to blood transfusion Hct was reduced to 20.33% ?1.91 % in group H and 29.64%?1.78% in group C. CK increased significantly at 4h after operation and on the 1st postoperative day; CK-MB increased significantly on the 1st postoperative day. The difference between the two groups was not significant. CTnI showed little change during and after operation in both groups.Conclusions Our study suggests that hemodilution to 20% Hct does not result in myocardial injury in patients without preexisting cardiopulmonary disease as long as normal blood volume is maintained and patient suffers nohypoxia.
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Objective To evaluate the effectiveness and safety of percutaneous subclavian venous catheterization through the point of insertion medial to the middle of clavicle in infants.Methods One hundred and fifty infants(88 male,62 female)aged 1-12 months scheduled for major operation were enrolled in this study. Subclavian venous catheterization was performed via supraclavicular approach.The needle was inserted at a point midway between the middle of clavicle and the inner third of clavicle(group Ⅰ,n=50)or at the point where the posterior border of sterno-cleidomastoid muscle(SCM)meets the upper border of clavicle(Yoffa method group Ⅱ, n=50)or at the posterior border of SCM,0.5-1.0 cm above the upper border of clavicle(modified James method,group Ⅲ,n=50).The overall success rate,the success rate at first attempt,the failure rate,the depth of insertion and complications were recorded.Results The 3 groups were comparable with respect to sex ratio,age and body weight.There were no significant differences in overall success rate and failure rate among the 3 groups. The success rate at first attempt in group Ⅰ(86%)was significantly higher than that in group Ⅱ(74%)and group Ⅲ(80%)(P＜0.05).The depth of insertion was significantly greater in group Ⅰ[(2.21+0.28)cm]than in group Ⅱ[(1.79?0.33)cm]and group Ⅲ[(1.84?0.38)cm].No pneumothorax and in advertent arterial puncture and nerve injury occurred in the 3 groups.Conclusion Supraclaricular subclavian venous catheterization through the insertion point medial to the middle of clavicle is better than the conventional methods(Yoffa,James) in terms of success rate at first attempt in infants.