Background There are few studies to assess whether propofol attenuates myocardial ischemia-reperfusion injury via a mechanism related to nitric oxide （NO） route, so we designed this randomized blinded experiment to ...Background There are few studies to assess whether propofol attenuates myocardial ischemia-reperfusion injury via a mechanism related to nitric oxide （NO） route, so we designed this randomized blinded experiment to observe the changes of NO contents, nitric oxide synthase （NOS） activity, NOS contents in the myocardium, and cardiac function in ischemic reperfused isolated rat hearts, and to assess the relation between myocardial NO system and cardioprotection of propofol. Methods The hearts of 30 Sprague-Dawley male rats were removed, mounted on a Langendorff apparatus, and randomly assigned to one of three groups （n=10 each group） to be treated with the following treatments in a blinded manner： Group 1, control group, after perfusion with pure Krebs Henseleit bicarbonate （K-HBB） buffer solution for 15 minutes, hearts were subjected to 20 minutes global ischemia followed by 60 minutes reperfusion with pure K-HBB buffer; Group 2, after perfusion with K-HBB buffer solution containing propofol （10 ug/ml） for 15 minutes, the hearts underwent 20 minutes global ischemia followed by 60 minutes reperfusion with the same K-HBB buffer solution; Group 3, after perfusion with K-HBB buffer solution containing propofol （10ug/ml） and L-NAME （100 umol/L） for 15 minutes, the hearts underwent 20 minutes global ischemia followed by 60 minutes reperfusion with the same K-HBB buffer solution. The cardiac function was continuously monitored throughout the experiment. The coronary flow was also measured. An ISO-NO electrode was placed into the right atrium close to the coronary sinus to continuously measure NO concentration in the coronary effluent. The tissue samples from apex of hearts in Groups 1 and 2 were obtained to measure the NOS activity by spectrophotometry and the NOS contents by immunohistochemistry, respectively. Results The cardiac function was significantly inhibited after ischemia and then gradually improved with reperfusion in all three groups. As compared with Group 1, the cardiac function variables and coronary flow at all the observed points were significantly improved in Group 2. The cardiac function variables and coronary flow were better in Group 3 than in Group 1, but were inferior in Group 3 than in Group 2. Both NO contents and NOS activity in the myocardium were significantly higher in Group 2 than in Group 1. However, NOS contents in the myocardium did not significantly differ between Groups 1 and 2. Conclusions In isolated rat hearts, propofol can improve cardiac functional recovery after ischemia-reperfusion by upregulating NOS activity in the myocardium. The NO system may play an important role in the preservation of myocardial ischemia-reperfusion injury produced by propofol.展开更多
Background There is few study to determine whether the use of the lightwand technique alone could achieve effective, safe and successful awake endotracheal intubation （ETI）, therefore we designed a prospective clini...Background There is few study to determine whether the use of the lightwand technique alone could achieve effective, safe and successful awake endotracheal intubation （ETI）, therefore we designed a prospective clinical study to systematically evaluate the feasibility, safety and efficacy of awake ETI using the lightwand alone in patients with difficult airways. Methods Seventy adult patients with difficult airways were enrolled in this study. After the desired sedation with fentanyl and midazolam, airway topical anesthesia was performed with 9 ml of 2% lidocaine, which were in order sprayed in three aliquots at 5 minutes intervals into the supraglottic （two doses） and laryngotracheal areas （one dose） using a combined unit of the lightwand and MADgic atomizer. After airway topical anesthesia, awake ETI was performed using a Lightwand. Subjective assessments by patients and operators using the visual analogue scores （VAS）, and objective assessments by an independent investigator using patients＇ tolerance and reaction scores, coughing severity, intubating conditions and cardiovascular variables were taken as the observed parameters. Results Of 210 airway sprays, 197 （93.8%） were successfully completed on the first attempt. The total time for airway spray was （14.6±1.5） minutes. During airway topical anesthesia, the average patients＇ tolerance scores were 1.7-2.3. After airway topical anesthesia, the mean VAS for discomfort levels that the patients reported was 6.5. Also airway topical anesthesia procedure was rated as acceptable and no discomfort by 94.3% of patients. The lightwand-guided awake ETI was successfully completed on first attempt within 29 seconds in all patients. During awake ETI, patients＇ reaction and coughing scores were 1.9 and 1.6, respectively. All patients exhibited excellent or acceptable intubating conditions. Cardiovascular monitoring revealed that changes of systolic blood pressure and heart rate at each stage of airway manipulations were less than 20% of baseline values. The postoperative follow-up showed that 95.7% of patients had no recall or slight memories of all airway instrumentation. The incidence of postoperative mild airway complications was 38.6%. Conclusion Alone use of the lightwand technique can achieve effective, safe and successful awake ETI in patients with difficult airways.展开更多
Background The authors found no study to compare the efficacy of bolus dose fentanyl and remifentanil blunting the cardiovascular intubation response in children, so they designed this randomized, double-blind clinica...Background The authors found no study to compare the efficacy of bolus dose fentanyl and remifentanil blunting the cardiovascular intubation response in children, so they designed this randomized, double-blind clinical study to assess the effects of remifentanil 2 μg/kg and fentanyl 2 μg/kg by bolus injection on the cardiovascular intubation response in healthy children.Methods One hundred and two children, the American Society of Anesthesiologists （ASA） physical status 1-2 and scheduled for elective plastic surgery under general anesthesia, were randomly divided into one of two groups to receive the following treatments in a double blind manner： remifentanil 2μg/kg （Group R） and fentanyl 2 μg/kg （Group F） when anesthesia was induced with propofol and vecuronium. The orotracheal intubation was performed using a direct laryngoscope. Blood pressure （BP） and heart rate （HR） were recorded before anesthesia induction （baseline values）, immediately before intubation, at intubation and every minute for 5 minutes after intubation. The percent changes of systolic blood pressure （SBP） and HR relative to baseline values and the rate pressure product （RPP） at every observing point were calculated. The incidences of SBP and HR percent changes 〉30% of baseline values and RPP 〉22 000 during the observation were recorded.Results There were no significant differences between groups in the demographic data, baseline values of BP and HR and the intubation time. As compared to baseline values, BP, HR and RPP at intubation and their maximum values during observation increased significantly in Group F, but they all decreased significantly in Group R. BP, HR and RPP at all observed points, and their maximum values during the observation, were significantly different between groups. There were also significant differences between groups in the percent change of SBP and HR relative to baseline values at all observed points and their maximum percent changes during the observation. The incidences of SBP and HR percent increased 〉30% of the baseline values and RPP 〉22 000 during the observation, were significantly higher in Group F than in Group R, but the incidences of SBP and HR percent decreased 〉30% of baseline values were significantly lower in Group F compared with Group R.Conclusions When used as part of routine anesthesia induction with propofol and vecuronium in children, fentanyl 2 μg/kg by bolus injection fails to effectively depress the cardiovascular intubation response. Remifentanil 2 μg/kg by bolus injection can completely abolish the cardiovascular intubation response, but also cause more adverse complications of temporary siclnificant cardiovascular depression.展开更多
Background Inflammation is one of important mechanisms for myocardial ischemia reperfusion injury （IRI）.Ischemia postconditioning （IPOC） can protect the heart against IRI by inhibiting inflammation,but its cardiop...Background Inflammation is one of important mechanisms for myocardial ischemia reperfusion injury （IRI）.Ischemia postconditioning （IPOC） can protect the heart against IRI by inhibiting inflammation,but its cardioprotection is weaker than that of ischemia preconditioning.Recently,the α7 subunit-containing nicotinic acetylcholine receptor （α7nAChR） agonist has shown anti-infiammatory effects in many diseases related to inflammation.This randomized controlled experiment was designed to evaluate whether combined postconditioning with IPOC and the α7nAChR agonist could produce an enhanced cardioprotection in a rat in vivo model of acute myocardial IRI.Methods Fifty Sprague-Dawley rats were randomly divided into five equal groups：sham group,control group,IPOC group,α7nAChR agonist postconditioning group （APOC group） and combined postconditioning with IPOC and α7nAChR agonist group （combined group）.Hemodynamic parameters were recorded during the periods of ischemia and reperfusion.Serum concentrations of troponin I （Tnl）,tumor necrosis factor α （TNF-α） and high-mobility group box 1 （HMGB-1） at 180 minutes after reperfusion were assayed in all groups.At the end of the experiment,the infarct size was assessed from excised hearts by Evans blue and triphenyl tetrazolium chloride staining.Results As compared to the sham group,the infarct size in the other four groups was significantly increased,serum levels of Tnl,TNF-α and HMGB1 in the control group and TNF-α,HMGB1 in the IPOC group were significantly increased.The infarct size and serum concentrations of TNF-α,HMGB1 and Tnl in the IPOC,APOC and combined groups were significantly lower than those in the control group.As compared to the IPOC group,the infarct size in the combined group was significantly decreased,serum concentrations of Tnl,TNF-α and HMGB1 in the APOC and combined groups were significantly reduced.Although the infarct size was significantly smaller in the combined group than in the APOC group,serum levels of TNF-α and HMGB1 were significantly higher in the combined group than in the APOC group.Conclusions In a rat in vivo model of acute myocardial IRI,combined postconditioning with IPOC and the α7nAChR agonist can produce enhanced protection against myocardial IRI by increasing the anti-inflammatory effect.展开更多
Background The GlideScope videolaryngoscope （GSVL） has been shown to have no special advantage over the Macintosh direct laryngoscope （MDL） in attenuating the circulatory responses to orotracheal intubation, but ...Background The GlideScope videolaryngoscope （GSVL） has been shown to have no special advantage over the Macintosh direct laryngoscope （MDL） in attenuating the circulatory responses to orotracheal intubation, but no study has compared the circulatory responses to nasotracheal intubation （NTI） using the two devices. This prospective randomized clinical study was designed to determine whether there was a clinically relevant difference between the circulatory responses to NTI with the GSVL and the MDL. Methods Seventy-six adult patients were randomly allocated equally to the GSVL group and the MDL group. After induction of anesthesia, NTI was performed. Non-invasive blood pressure （BP） and heart rate （HR） were recorded before induction （baseline values） and immediately before intubation （post-induction values）, at intubation and every minute for a further five minutes. During the observation, times required to reach the maximum values of systolic BP （SBP） and HR, times required for recovery of SBP and HR to postinduction values and incidence of SBP and HR percent changes 〉 30% of baseline values were also noted. The product of HR and systolic BP, i.e. rate pressure product （RPP）, and the areas under SBP and HR vs. time curves （AUGsBP and AUGHR） were calculated. Results The NTI with the GSVL resulted in significant increases in BP, HR and RPP compared to postinduction values, but these circulatory changes did not exceed baseline values. BPs at all measuring points, AUGSBP, maximum values of BP and incidence of SBP percent increase 〉 30% of baseline value during the observation did not differ significantly between groups. However, HR and RPP at intubation and their maximum values, AUGHR and incidence of HR percent increase 〉 30% of baseline value were significantly higher in the MDL group than in the GSVL group. Times required for recovery of SBP and HR to postinduction values were significantly longer in the MDL group than in the GSVL group. Conclusions The pressor response to NTI with the GSVL and the MDL was similar, but the tachycardiac response to NTI was lesser and of a shorter duration when using a GSVL than when using an MDL.展开更多
Background Both ischemic preconditioning （IPC） and limb remote ischemic postconditioning （LRIPOC） have been shown to possess significantly different cardioprotective effects against the myocardial ischemia reperfu...Background Both ischemic preconditioning （IPC） and limb remote ischemic postconditioning （LRIPOC） have been shown to possess significantly different cardioprotective effects against the myocardial ischemia reperfusion injury （IRI）, but no study has compared the anti-inflammatory effects of IPC and LRIPOC during myocardial IRI process. We hypothesized that IPC and LRIPOC would produce different anti-inflammatory effects in an in vivo rat model with myocardial IRI.展开更多
To the editor： In a retrospective observational clinical study including 482 elderly patients with coronary heart diseaseundergoing elective major noncardiac surgery, Liu et al＇ showed that the incidence ofperiopera...To the editor： In a retrospective observational clinical study including 482 elderly patients with coronary heart diseaseundergoing elective major noncardiac surgery, Liu et al＇ showed that the incidence ofperioperative major adverse cardiac events （MACEs） was 12.7%, and five risk factors were independently associated with perioperative MACEs. This study makes an important contribution to the effort to define risk factors for perioperative MACEs in elderly patients with coronary heart disease undergoing noncardiac surgery. Strengths of this study include a large sample of patients and most of the known risk factors that can affect perioperative MACEs. Furthermore, the authors have used appropriate methods to identify independent risk factors for perioperative MACEs. However, in our view, there are several aspects of this study that should be considered.展开更多
文摘Background There are few studies to assess whether propofol attenuates myocardial ischemia-reperfusion injury via a mechanism related to nitric oxide （NO） route, so we designed this randomized blinded experiment to observe the changes of NO contents, nitric oxide synthase （NOS） activity, NOS contents in the myocardium, and cardiac function in ischemic reperfused isolated rat hearts, and to assess the relation between myocardial NO system and cardioprotection of propofol. Methods The hearts of 30 Sprague-Dawley male rats were removed, mounted on a Langendorff apparatus, and randomly assigned to one of three groups （n=10 each group） to be treated with the following treatments in a blinded manner： Group 1, control group, after perfusion with pure Krebs Henseleit bicarbonate （K-HBB） buffer solution for 15 minutes, hearts were subjected to 20 minutes global ischemia followed by 60 minutes reperfusion with pure K-HBB buffer; Group 2, after perfusion with K-HBB buffer solution containing propofol （10 ug/ml） for 15 minutes, the hearts underwent 20 minutes global ischemia followed by 60 minutes reperfusion with the same K-HBB buffer solution; Group 3, after perfusion with K-HBB buffer solution containing propofol （10ug/ml） and L-NAME （100 umol/L） for 15 minutes, the hearts underwent 20 minutes global ischemia followed by 60 minutes reperfusion with the same K-HBB buffer solution. The cardiac function was continuously monitored throughout the experiment. The coronary flow was also measured. An ISO-NO electrode was placed into the right atrium close to the coronary sinus to continuously measure NO concentration in the coronary effluent. The tissue samples from apex of hearts in Groups 1 and 2 were obtained to measure the NOS activity by spectrophotometry and the NOS contents by immunohistochemistry, respectively. Results The cardiac function was significantly inhibited after ischemia and then gradually improved with reperfusion in all three groups. As compared with Group 1, the cardiac function variables and coronary flow at all the observed points were significantly improved in Group 2. The cardiac function variables and coronary flow were better in Group 3 than in Group 1, but were inferior in Group 3 than in Group 2. Both NO contents and NOS activity in the myocardium were significantly higher in Group 2 than in Group 1. However, NOS contents in the myocardium did not significantly differ between Groups 1 and 2. Conclusions In isolated rat hearts, propofol can improve cardiac functional recovery after ischemia-reperfusion by upregulating NOS activity in the myocardium. The NO system may play an important role in the preservation of myocardial ischemia-reperfusion injury produced by propofol.
文摘Background There is few study to determine whether the use of the lightwand technique alone could achieve effective, safe and successful awake endotracheal intubation （ETI）, therefore we designed a prospective clinical study to systematically evaluate the feasibility, safety and efficacy of awake ETI using the lightwand alone in patients with difficult airways. Methods Seventy adult patients with difficult airways were enrolled in this study. After the desired sedation with fentanyl and midazolam, airway topical anesthesia was performed with 9 ml of 2% lidocaine, which were in order sprayed in three aliquots at 5 minutes intervals into the supraglottic （two doses） and laryngotracheal areas （one dose） using a combined unit of the lightwand and MADgic atomizer. After airway topical anesthesia, awake ETI was performed using a Lightwand. Subjective assessments by patients and operators using the visual analogue scores （VAS）, and objective assessments by an independent investigator using patients＇ tolerance and reaction scores, coughing severity, intubating conditions and cardiovascular variables were taken as the observed parameters. Results Of 210 airway sprays, 197 （93.8%） were successfully completed on the first attempt. The total time for airway spray was （14.6±1.5） minutes. During airway topical anesthesia, the average patients＇ tolerance scores were 1.7-2.3. After airway topical anesthesia, the mean VAS for discomfort levels that the patients reported was 6.5. Also airway topical anesthesia procedure was rated as acceptable and no discomfort by 94.3% of patients. The lightwand-guided awake ETI was successfully completed on first attempt within 29 seconds in all patients. During awake ETI, patients＇ reaction and coughing scores were 1.9 and 1.6, respectively. All patients exhibited excellent or acceptable intubating conditions. Cardiovascular monitoring revealed that changes of systolic blood pressure and heart rate at each stage of airway manipulations were less than 20% of baseline values. The postoperative follow-up showed that 95.7% of patients had no recall or slight memories of all airway instrumentation. The incidence of postoperative mild airway complications was 38.6%. Conclusion Alone use of the lightwand technique can achieve effective, safe and successful awake ETI in patients with difficult airways.
文摘Background The authors found no study to compare the efficacy of bolus dose fentanyl and remifentanil blunting the cardiovascular intubation response in children, so they designed this randomized, double-blind clinical study to assess the effects of remifentanil 2 μg/kg and fentanyl 2 μg/kg by bolus injection on the cardiovascular intubation response in healthy children.Methods One hundred and two children, the American Society of Anesthesiologists （ASA） physical status 1-2 and scheduled for elective plastic surgery under general anesthesia, were randomly divided into one of two groups to receive the following treatments in a double blind manner： remifentanil 2μg/kg （Group R） and fentanyl 2 μg/kg （Group F） when anesthesia was induced with propofol and vecuronium. The orotracheal intubation was performed using a direct laryngoscope. Blood pressure （BP） and heart rate （HR） were recorded before anesthesia induction （baseline values）, immediately before intubation, at intubation and every minute for 5 minutes after intubation. The percent changes of systolic blood pressure （SBP） and HR relative to baseline values and the rate pressure product （RPP） at every observing point were calculated. The incidences of SBP and HR percent changes 〉30% of baseline values and RPP 〉22 000 during the observation were recorded.Results There were no significant differences between groups in the demographic data, baseline values of BP and HR and the intubation time. As compared to baseline values, BP, HR and RPP at intubation and their maximum values during observation increased significantly in Group F, but they all decreased significantly in Group R. BP, HR and RPP at all observed points, and their maximum values during the observation, were significantly different between groups. There were also significant differences between groups in the percent change of SBP and HR relative to baseline values at all observed points and their maximum percent changes during the observation. The incidences of SBP and HR percent increased 〉30% of the baseline values and RPP 〉22 000 during the observation, were significantly higher in Group F than in Group R, but the incidences of SBP and HR percent decreased 〉30% of baseline values were significantly lower in Group F compared with Group R.Conclusions When used as part of routine anesthesia induction with propofol and vecuronium in children, fentanyl 2 μg/kg by bolus injection fails to effectively depress the cardiovascular intubation response. Remifentanil 2 μg/kg by bolus injection can completely abolish the cardiovascular intubation response, but also cause more adverse complications of temporary siclnificant cardiovascular depression.
文摘Background Inflammation is one of important mechanisms for myocardial ischemia reperfusion injury （IRI）.Ischemia postconditioning （IPOC） can protect the heart against IRI by inhibiting inflammation,but its cardioprotection is weaker than that of ischemia preconditioning.Recently,the α7 subunit-containing nicotinic acetylcholine receptor （α7nAChR） agonist has shown anti-infiammatory effects in many diseases related to inflammation.This randomized controlled experiment was designed to evaluate whether combined postconditioning with IPOC and the α7nAChR agonist could produce an enhanced cardioprotection in a rat in vivo model of acute myocardial IRI.Methods Fifty Sprague-Dawley rats were randomly divided into five equal groups：sham group,control group,IPOC group,α7nAChR agonist postconditioning group （APOC group） and combined postconditioning with IPOC and α7nAChR agonist group （combined group）.Hemodynamic parameters were recorded during the periods of ischemia and reperfusion.Serum concentrations of troponin I （Tnl）,tumor necrosis factor α （TNF-α） and high-mobility group box 1 （HMGB-1） at 180 minutes after reperfusion were assayed in all groups.At the end of the experiment,the infarct size was assessed from excised hearts by Evans blue and triphenyl tetrazolium chloride staining.Results As compared to the sham group,the infarct size in the other four groups was significantly increased,serum levels of Tnl,TNF-α and HMGB1 in the control group and TNF-α,HMGB1 in the IPOC group were significantly increased.The infarct size and serum concentrations of TNF-α,HMGB1 and Tnl in the IPOC,APOC and combined groups were significantly lower than those in the control group.As compared to the IPOC group,the infarct size in the combined group was significantly decreased,serum concentrations of Tnl,TNF-α and HMGB1 in the APOC and combined groups were significantly reduced.Although the infarct size was significantly smaller in the combined group than in the APOC group,serum levels of TNF-α and HMGB1 were significantly higher in the combined group than in the APOC group.Conclusions In a rat in vivo model of acute myocardial IRI,combined postconditioning with IPOC and the α7nAChR agonist can produce enhanced protection against myocardial IRI by increasing the anti-inflammatory effect.
文摘Background The GlideScope videolaryngoscope （GSVL） has been shown to have no special advantage over the Macintosh direct laryngoscope （MDL） in attenuating the circulatory responses to orotracheal intubation, but no study has compared the circulatory responses to nasotracheal intubation （NTI） using the two devices. This prospective randomized clinical study was designed to determine whether there was a clinically relevant difference between the circulatory responses to NTI with the GSVL and the MDL. Methods Seventy-six adult patients were randomly allocated equally to the GSVL group and the MDL group. After induction of anesthesia, NTI was performed. Non-invasive blood pressure （BP） and heart rate （HR） were recorded before induction （baseline values） and immediately before intubation （post-induction values）, at intubation and every minute for a further five minutes. During the observation, times required to reach the maximum values of systolic BP （SBP） and HR, times required for recovery of SBP and HR to postinduction values and incidence of SBP and HR percent changes 〉 30% of baseline values were also noted. The product of HR and systolic BP, i.e. rate pressure product （RPP）, and the areas under SBP and HR vs. time curves （AUGsBP and AUGHR） were calculated. Results The NTI with the GSVL resulted in significant increases in BP, HR and RPP compared to postinduction values, but these circulatory changes did not exceed baseline values. BPs at all measuring points, AUGSBP, maximum values of BP and incidence of SBP percent increase 〉 30% of baseline value during the observation did not differ significantly between groups. However, HR and RPP at intubation and their maximum values, AUGHR and incidence of HR percent increase 〉 30% of baseline value were significantly higher in the MDL group than in the GSVL group. Times required for recovery of SBP and HR to postinduction values were significantly longer in the MDL group than in the GSVL group. Conclusions The pressor response to NTI with the GSVL and the MDL was similar, but the tachycardiac response to NTI was lesser and of a shorter duration when using a GSVL than when using an MDL.
文摘Background Both ischemic preconditioning （IPC） and limb remote ischemic postconditioning （LRIPOC） have been shown to possess significantly different cardioprotective effects against the myocardial ischemia reperfusion injury （IRI）, but no study has compared the anti-inflammatory effects of IPC and LRIPOC during myocardial IRI process. We hypothesized that IPC and LRIPOC would produce different anti-inflammatory effects in an in vivo rat model with myocardial IRI.
文摘To the editor： In a retrospective observational clinical study including 482 elderly patients with coronary heart diseaseundergoing elective major noncardiac surgery, Liu et al＇ showed that the incidence ofperioperative major adverse cardiac events （MACEs） was 12.7%, and five risk factors were independently associated with perioperative MACEs. This study makes an important contribution to the effort to define risk factors for perioperative MACEs in elderly patients with coronary heart disease undergoing noncardiac surgery. Strengths of this study include a large sample of patients and most of the known risk factors that can affect perioperative MACEs. Furthermore, the authors have used appropriate methods to identify independent risk factors for perioperative MACEs. However, in our view, there are several aspects of this study that should be considered.
