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Objective To evaluate the ability of pleth variability index(PVI) for predicting volume responsiveness after general anesthesia induction intubation in the patients undergoing intestinal tract surgery with the velocity-time integral(VTI) of left ventricular outflow tract blood monitored by transthoracic echocardiography as the standard.Methods Twenty-five patients undergoing intestinal tract surgery were selected.After general anesthesia induction,7 mL/kg colloidal solution was infused before operation beginning,if the VTI increased percentage(△VTI％)≥10 ％,200 mL colloidal solution was infused by 50mL syringe until △VTI％＜10％;the hemodynamic indicators of MAP,CVP,HR,PI VTI and PVI were recorded before and after infusion solution.Results The PVI basic value in the patients with response was significantly higher than that in the patients without response(P＜0.05);the Pearson correlation analysis found that there was a significant linear correlation between PVI basic value and △VTI％ before infusion solution(P＜0.05);the optimal diagnostic threshold value of PVI was 13.51,its sensitivity for monitoring the volume responsiveness was 69.25％ and specificity was 70.00％.The area under the receiver operating characteristic(ROC) curve(AUC) was 0.75(95％ CI:0.63-0.88,P＜0.01).Conclusion PVI can predict the volume responsiveness in the patients undergoing intestinal tract surgery.The PVI value ＞13.51 indicates that the patient may be in hypovolemia status and needs the volume therapy.
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Objective To evaluate the effect of methylene blue(MB)preconditioning on ischemi-a-reperfusion(I∕R)injury in isolated rat lungs. Methods Eighteen pathogen-free healthy male Sprague-Dawley rats, aged 3 months, weighing 240-320 g, were divided into 3 groups(n=6 each)using a ran-dom number table: sham operation group(group Sham), lung I∕R group(group I∕R)and methylene blue preconditioning group(group MB). A model of isolated lung I∕R injury was established in pentobarbi-tal sodium-anesthetized rats. MB 2 mg∕kg was intraperitoneally injected at 2 h before stopping perfusion in group MB. Isolated lungs were perfused for 20 min, followed by 45-min ischemia, and then reperfused for 60 min in I∕R and MB groups. At 60 min of reperfusion, the activity of lactic dehydrogenase(LDH)in the perfusate was detected, wet weight(W)and dry weight(D)was determined, W∕D ratio was calcu-lated, and the levels of malondialdehyde(MDA), ATP, reactive oxygen species(ROS)and superoxide dismutase(SOD)were measured in lung tissues. Mitochondria and cytoplasm were isolated from lung tis-sues for determination of mitochondrial membrane potential(MMP), degree of mitochondrial swelling and content of cytochrome C(Cyt c)in cytoplasm. Apoptotic cells in lung tissues were detected using TUNEL, and apoptotic index was calculated. Results Compared with group Sham, the activity of LDH in perfu-sate, W∕D ratio, levels of ROS, MDA and Cyt c in cytoplasm and apoptosis index were significantly in-creased, the degree of mitochondrial swelling was aggravated, and the content of ATP and MMP were de-creased in I∕R and MB groups, and the SOD activity was significantly decreased in group I∕R(P<005). Compared with group I∕R, the activity of LDH in perfusate, W∕D ratio, levels of ROS, MDA and Cyt c in cytoplasm and apoptosis index were significantly decreased, the degree of mitochondrial swelling was attenu-ated, and the activity of SOD, content of ATP and MMP were increased in group MB(P<005). Con-clusion Methylene blue preconditioning can reduce I∕R injury in isolated rat lungs, and the mechanism may be related to improving mitochondrial function and inhibiting cell apoptosis.
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Objective To compare the efficacy of laryngeal mask airway-Advance (ALMA) and laryngeal mask airway-Supreme (S-LMA) in patients undergoing laparoscopic cholecystectomy.Methods Two hundred and forty ASA Ⅰ or Ⅱ patients,aged 18-64 yr,weighing 50-70 kg,undergoing laparoscopic cholecystectomy,were randomly divided into2 groups (n=120 each):group S-LMA (group S) and group A-LMA (group A).LMA was inserted after induction of general anesthesia with propofol 2.0-2.5 mg/kg,sufentanil 0.2 μg/kg and rocuronium 0.6 mg/kg.After LMA was placed,the rim was immediately inflated and positive pressure was applied to the reservoir bag of anesthesia machine circuit to check for leaks.The plateau pressure at which leaks occurred was recorded.BP,HR,SpO2,PErCO2 and Ppeak were monitored during operation.Fiberoptic bronchoscopy was performed and the placement was scored (0 =unable to see the vocal cords and the ventilation of the lungs was inadequate,4=vocal cords were clearly seen and ventilation was adequate).The rate of successful placement,placement time,the incidence of leaks during operation,duration of anesthesia and surgery,extubation time,emergence time,blood stain on the LMA after being removed,backflow after extubation and postoperatve complacations including sore throat,hoarseness and dysphagia were recorded.The efficacy for airway management and the difficulty of placement were scored.Results There was no significant difference in the rate of successful placement,difficulty of placement scores,blood stain on the LMA after being removed,incidence of backflow,sore throat,hoarseness and dysphogia,anesthesia time,duration of surgery,extubation time and emergence time between the two groups.The placement time was shorter in group S than in group A,but the airway sealing pressure,FOB scores and efficacy for airway management scores were significantly higher and the incidence of leaks during operation was significantly lower in group A than in group S.Conclusion Both A-LMA and S-LMA can provide adequate ventilation during laparoscopic cholecystectomy.The efficacy of A-LMA is better.
ABSTRACT
A patent cardiac support system which is used as a bridge treatment for acute myocardial infarction has been designed and tested in vitro and in two dogs in vivo. This is an easy-to-use intelligentized pulsatile flow cardiopulmonary bypass device to replace the function of heart. The device consists of two identical pumps and perfusion chambers, a sensing and control system, a gas exchanger between the vein and pump, two one way valves between pump and veins or arteries. Arterial pressure and EKG feedback mechanisms are used for maintaining blood pressure and coordinating the pumping activity with heart contraction. A prototype of the device was built to perform hydraulic in vitro tests with aims of verifying the new device's pumping behavior. Functional evaluation of the device was carried out by using it in a model circuit made with standard CPB components plus a mock hydraulic pipeline. This system demonstrated easy manipulation, good controllability, and provided a 65+/-2ml x beat(-1) flow volume. There was a linear correlation between peak pressure value and pulsatile frequency. In the two in vivo experiments, the primary objective was to determine whether the device could work well in dog, whether physiologic pulsatility could be achieved and whether the blood supply to heart should be sufficient during asystole status by drugs. The results suggest that all the goals have been achieved.