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Objective:To evaluate the effect of propofol and remifentanil in different target-controlled infusion(TCI) sequences on hypotension during induction of general anesthesia in hypertensive patients.Methods:A total of 132 patients with hypertension of both sexes, aged 50-75 yr, of American Society of Anesthesiologists Physical Status classificationⅡ or Ⅲ, with body mass index of 18-30 kg/m 2, scheduled for elective tracheal intubation under general anesthesia, were divided into 3 groups( n=44 each) using a random number table method: group C, PR group and RP group. In group C, propofol(target effect-site concentration 5 μg/ml) and remifentanil(target effect-site concentration 5 ng/ml) were simultaneously given by TCI. Propofol was given by TCI followed by TCI of remifentanil in PR group. Remifentanil was given by TCI followed by TCI of propofol in RP group. The development of hypotension was observed within 10 min after induction of general anesthesia, and the consumption of propofol, remifentanil and ephedrine, time of loss of consciousness, time of tracheal intubation and adverse reactions during the perioperative period were recorded. Results:Compared with group C, the incidence of hypotension during induction was significantly decreased, the consumption of propofol and ephedrine was decreased, and the BIS value was increased when consciousness disappeared, the time of loss of consciousness and time of tracheal intubation were prolonged, the BIS value was increased at loss of consciousness in PR group, and the consumption of ephedrine was significantly decreased, and the time of loss of consciousness and time of tracheal intubation were prolonged in RP group( P<0.05). Compared with PR group, the consumption of ephedrine was significantly decreased, and the time of loss of consciousness was prolonged in RP group( P<0.05). There was no significant difference in the incidence of responses to tracheal intubation, injection pain, bucking, inhibition ratio, postoperative delirium, postoperative nausea and vomiting, and intraoperative awareness during induction among the three groups( P>0.05). Conclusions:TCI of remifentanil followed by TCI of propofol can decrease the development of hypotension during induction of general anesthesia in hypertensive patients.
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Objective:To compare the efficacy of individualized PEEP determined by lung electrical impedance tomography (EIT) and dynamic lung compliance (Cdyn) during lung-protective ventilation strategies in the patients undergoing general anesthesia.Methods:Sixty patients of both sexes, aged 18-64 yr, of American Society of Anesthesiologists physical status Ⅰor Ⅱ, with body mass index of 18.5-28.0 kg/m 2, undergoing elective surgery with general anesthesia and endotracheal intubation in the Second Affiliated Hospital of Soochow University, were selected.Lung-protective ventilation strategy was applied in supine position after general anesthesia.The peak value of PEEP did not exceed 10 cmH 2O, with an increment/decrement of 2 cmH 2O for titration.The corresponding Cdyn value and lung EIT data were collected during titration.The patients were divided into 2 groups ( n=30 each) using a random number table method: titration first increased and then decreased group (group A) and titration first decreased and then increased group (group B). The determination method of individualized PEEP: Cdyn method was the PEEP corresponding to the maximum Cdyn value; EIT method was obtained through PV500 PC software analysis.The level and success rate of individualized PEEP determined by the Cdyn and EIT methods were compared, and the ICC consistency analysis of the determined individualized PEEP was performed. Results:Compared with the Cdyn method, the success rate of individualized PEEP determined by EIT method was significantly increased, and the level of individualized PEEP was decreased in the two group ( P<0.05). In group A, the individualized PEEP titrated by the EIT and Cdyn methods showed good agreement (the ICC value of the increment-Cdyn and increment-EIT methods was 0.761, P<0.05; the ICC value of the decrement-Cdyn and decrement-EIT methods was 0.763, P<0.05). In group B, the individualized PEEP titrated by the EIT and Cdyn methods showed good agreement (the ICC value of the increment-Cdyn and increment-EIT methods was 0.809, P<0.05; the ICC value of the decrement-Cdyn and decrement-EIT methods was 0.797, P<0.05). Conclusion:The agreement between the individualized PEEP determined by lung EIT method and Cdyn method during lung-protective ventilation is good in the patients undergoing general anesthesia, and the success rate of EIT method is higher, and the level of individualized PEEP is lower.
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Objective To determine the optimal positive end-expiratory pressure (PEEP) for volume-controlled ventilation using pulmonary electrical impedance tomography in the patients undergoing surgery with general anesthesia.Methods Fifty patients of both sexes,aged 18-64 yr,of American Society of Anesthesiologists physical status Ⅰ or Ⅱ,with body mass index of 18.5-28.0 kg/m2,scheduled for surgery for ureteral calculi under general anesthesia,were enrolled in this study.The patients were tracheally intubated after anesthesia induction and mechanically ventilated in volume-controlled mode,with tidal volume 6 ml/kg,mean arterial pressure was recorded at 3 min of ventilation and served as the baseline value,and then PEEP was increased with an increment of 3 cmH2O every 3 min until PEEP reached 15 cmH2 O.The percentage of dorsal pulmonary ventilation and peak airway pressure were recorded at 3 min of ventilation with different PEEPs.When the decrease in mean arterial pressure was more than 20％ of the baseline value during ventilation,deoxyepinephrine 0.1 mg was injected intravenously,and the consumption of deoxyepinephrine was recorded within 3 min of ventilation with different PEEPs.Results Peak airway pressure was gradually increased with the increase of PEEP (P＜0.05),the percentage of dorsal pulmonary ventilation was gradually increased when PEEP was 6 cmH2O (P＜ 0.05),and the consumption of deoxyepinephrine was gradually increased when PEEP was 15 cmH2O (P＜0.05).Conclusion The optimal PEEP is 12 cmH2O during volume-controlled ventilation with tidal volume of 6 ml/kg in the patients undergoing surgery with general anesthesia.
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Objective To evaluate the effect of prefilling blood reservoir with mannitol-adeninephosphate MAP) solution on the damage to erythrocytes in intraoperative salvaged blood in patients.Methods One hundred and fifty blood samples were collected from 150 patients who were scheduled for elective spinal surgery requiring blood salvage,and were equally and randomly divided into 5 groups (n =30 each) using a random number table:group N,group N1,group N2,group M1 and group M2.The blood reservoir was not prefilled before surgery in group N,while the blood reservoirs in N1,N2,M1 and M2 groups were prefilled with normal saline (NS) 100 ml,NS 200 ml,MAP solution 100 ml and MAP solution 200 ml,respectively.Blood sauples were obtained for erythrocyte osmotic fragility test after the salvaged blood was washed,and hemolysis rates in different concentrations of hypotonic NaCl solution were calculated.The concentration of free hemoglobin in the clear supernatant liquid (FHb) of washed blood placed for 0 h (T0),1 h (T1) and 2 h (T2) were detected.Results Compared with N and N1 groups,the hemolysis rate of washed erythrocytes under 0.48％ 0.68％ NaCl solutions was significantly decreased,the concentration of FHb at T1 was decreased,and no significant change was found in FHb at T2 in group M1.Compared with N and N2 groups,the haemolysis rates of washed erythrocytes under 0.48％-0.68％ NaCl solutions were significantly decreased,and the concentrations of FHb at T1,2 were decreased in group M2.The concentration of FHb was significantly lower at T2 in group M2 than in group M1.Conclusion Prefilling blood reservoir with MAP solution can mitigate the damage to erythrocytes in the intraoperative salvaged blood in patients,and the efficacy of prefilling of 200 ml is superior to that of prefilling of 100 ml.
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BACKGROUND:Anterior cruciate ligament injury can trigger knee instability, knee osteoarthritis which decreases human beings’ life quality. Exploration on non-contact anterior cruciate ligament injury mechanism can prevent the occurrence of anterior cruciate ligament injury. OBJECTIVE:To investigate the mechanism of fatigue effect on non-contact anterior cruciate ligament injury and to introduce the progression of fatigue effect on non-contact anterior cruciate ligament injury in jump-landing activities. METHODS:The author retrieved the PubMed database from 1988 to 2013 by computer. The key words were set as:ACL, landing, and fatigue. A total of 42 articles were included which related to biomechanics research on anterior cruciate ligament injury, fatigue landing and low-limb injury. RESULTS AND CONCLUSION:In jump-landing activities, knee valgus, moment, knee joint rotation and smal er knee flexion are main biomechanics underlying non-contact anterior cruciate ligament injury. In addition, fatigue effect is another critical factor for non-contact anterior cruciate ligament injury. However, the cause-effect between fatigue effect and anterior cruciate ligament injury is not clearly investigated and summarized, especial y on fatigue level, fatigue induction and movement control. Introduction of fatigue induction is crucial for better understanding how fatigue effect results in anterior cruciate ligament injury. Thus, the quantification of fatigue level, fatigue models and landing ways wil provide new ideas for exploring biomechanical mechanism underlying anterior cruciate ligament injury in fatigue state, as wel as provide more information on intervention design and injury rehabilitation.