Propofol affects mouse embryonic fibroblast survival and proliferation in vitro via ATG5- and calcium-dependent regulation of autophagy.

Propofol is a commonly used intravenous anesthetic agent, which has been found to affect cell survival and proliferation especially in early life. Our previous studies show that propofol-induced neurodegeneration and neurogenesis are closely associated with cell autophagy. In the present study we explored the roles of autophagy-related gene 5 (ATG5) in propofol-induced autophagy in mouse embryonic fibroblasts (MEF) in vitro. We showed that ATG5 was functionally related to propofol-induced cell survival and damage: propofol significantly enhanced cell survival and proliferation at a clinically relevant dose (10 µM), but caused cell death at an extremely high concentration (200 µM) in ATG5-/- MEF, but not in WT cells. The dual effects found in ATG5-/- MEF could be blocked by intracellular Ca2+ channel antagonists. We also found that propofol evoked a moderate (promote cell growth) and extremely high (cause apoptosis) cytosolic Ca2+ elevation at the concentrations of 10 µM and 200 µM, respectively, only in ATG5-/- MEF. In addition, ATG5-/- MEF themselves released more Ca2+ in cytosolic space and endoplasmic reticulum compared with WT cells, suggesting that autophagy deficiency made intracellular calcium signaling more vulnerable to external stimuli (propofol). Altogether, our results reveal that ATG5 plays a crucial role in propofol regulation of cell survival and proliferation by affecting intracellular Ca2+ homeostasis.

A single-dose of stellate ganglion block for the prevention of postoperative dysrhythmias in patients undergoing thoracoscopic surgery for cancer: A randomised controlled double-blind trial.

BACKGROUND: New-onset arrhythmias and sleep disturbances are frequently observed during the postoperative period in patients undergoing thoracic surgery. OBJECTIVE: We evaluated the effectiveness of a single-dose stellate ganglion block (SGB) to prevent the occurrence of arrhythmias in patients undergoing thoracic surgery for cancer. DESIGN: Randomised controlled double-blind study. SETTING: Single university hospital. PATIENTS: Ninety patients with lung cancer or oesophagal cancer scheduled for elective video-assisted thoracoscopic surgery were randomly randomised into one of two equal groups (the SGB group and control group, n = 40 each). INTERVENTIONS: Patients received a single dose of 5 ml of 0.5% ropivacaine during ultrasound-guided SGB before induction of general anaesthesia in the SGB group. MAIN OUTCOME MEASURES: Holter ECG was continuously monitored during the first 48 postoperative hours, and sleep state was monitored during the first two postoperative nights. RESULTS: The incidences of postoperative supraventricular tachycardias were lower in the SGB group compared with the control group during the first 48 postoperative hours; 11.6 (5/43) vs. 31.8% (14/44), respectively, P = 0.023 (odds ratio 0.28, 95% confidence interval 0.09 to 0.87). The SGB also prolonged the total sleep time and increased the sleep efficiency during the first two postoperative nights. The duration of stage N2 sleep was longer in the SGB group compared with the control group [28 (interquartile range, 14 to 58) to 94 (interquartile range, 69 to 113) min, P = 0.016] on the first postoperative night. There were no differences in the duration of stage N1 and N3 sleep (P = 0.180, 0.086, respectively) on the first postoperative night, and the duration of stage N1, N2 and N3 sleep (P = 0.194, 0.057, 0.405, respectively) on the second postoperative night between the groups. CONCLUSION: A pre-operative SGB effectively prevented the occurrence of postoperative supraventricular tachycardias and improves the objective sleep quality in patients undergoing thoracic surgery for cancer. TRIAL REGISTRATION NUMBER: ChiCTR-1900023064.

Expert Recommendations for Tracheal Intubation in Critically ill Patients with Noval Coronavirus Disease 2019.

Coronavirus Disease 2019 (COVID-19), caused by a novel coronavirus (SARS-CoV-2), is a highly contagious disease. It firstly appeared in Wuhan, Hubei province of China in December 2019. During the next two months, it moved rapidly throughout China and spread to multiple countries through infected persons travelling by air. Most of the infected patients have mild symptoms including fever, fatigue and cough. But in severe cases, patients can progress rapidly and develop to the acute respiratory distress syndrome, septic shock, metabolic acidosis and coagulopathy. The new coronavirus was reported to spread via droplets, contact and natural aerosols from human-to-human. Therefore, high-risk aerosol-producing procedures such as endotracheal intubation may put the anesthesiologists at high risk of nosocomial infections. In fact, SARS-CoV-2 infection of anesthesiologists after endotracheal intubation for confirmed COVID-19 patients have been reported in hospitals in Wuhan. The expert panel of airway management in Chinese Society of Anaesthesiology has deliberated and drafted this recommendation, by which we hope to guide the performance of endotracheal intubation by frontline anesthesiologists and critical care physicians. During the airway management, enhanced droplet/airborne PPE should be applied to the health care providers. A good airway assessment before airway intervention is of vital importance. For patients with normal airway, awake intubation should be avoided and modified rapid sequence induction is strongly recommended. Sufficient muscle relaxant should be assured before intubation. For patients with difficult airway, good preparation of airway devices and detailed intubation plans should be made.

[Effects of electroacupuncture assistant general anesthesia on postoperative cognitive dysfunction of aged patients].

OBJECTIVE: To observe the effects of electroacupuncture (EA) assistant general anesthesia on postoperative cognitive dysfunction (POCD) of aged patients. METHODS: One hundred and twenty senile American Society of Anesthesiology (ASA) grade I - III patients (more than 65 years old) with non-cardiac surgery were randomly assigned to two groups, Group A and Group B, 60 cases in each group. Patients in Group A received general anesthesia, while those in Group B received EA assistant general anesthesia. Patients in Group B received EA at Baihui (DU20), Hegu (LI4), Neiguan (PC6), Zusanli (ST36) 30 min before anesthesia induction to the end of operation. Anesthesia was induced by etomidate 0.2 - 0.3 mg/kg, fentanyl 3-5 microg/kg, cisatracurium 0.15 mg/kg in the two groups. Anesthesia maintenance was provided by sevoflurane and continuous pumping of remifentanil. Tramadol 50 mg was given 30 min before ending the operation. The scores of mini-mental state examination (MMSE), nausea and vomiting were recorded in the two groups one day before anesthesia, the 2nd, 4th, and 6th day after operation. The occurrence of postoperative cognitive dysfunction (POCD) on day 2, 4, and 6 was compared. RESULTS: The occurrence of POCD on day 2 and 4 was obviously lower in Group B than in Group A at the same time period (40.0% vs 66.7%, 13.3% vs 43.3%), showing statistical difference (P < 0.05). There was no significant difference in the pre-anesthesia scores of MMSE between the two groups. The scores of MMSE on the 2nd and the 4th day were higher in Group B than in Group A (21.3 +/- 3.9 vs 18.3 +/- 3.8, 26.4 +/- 2.9 vs 22.9 +/- 3.9, P < 0.05). Compared with one day before anesthesia in the same group, the scores of MMSE were significantly different on the 2nd and the 4th day (Group A: 18.3 +/- 3.8, 22.9 +/- 3.9 vs 27.9 +/- 2.1; Group B: 21.3 +/- 3.9 vs 27.5 +/- 2.5; P < 0.05). The occurrence of post-aesthesia nausea and vomiting was lower in Group B (23.3%, 14/60) than in Group A (46.7%, 28/60) with statistical difference (P < 0.05). CONCLUSION: EA assistant general anesthesia could reduce the occurrence of POCD in aged patients.

[Effects of ligustrazine injection on IL-2, IL-10, and IFN-gamma in patients undergoing spinal operation after autologous blood transfusion].

OBJECTIVE: To study the regulatory effect of Ligustrazine Injection (LI) on the cellular immune function in patients undergoing autologous blood transfusion (ABT). METHODS: Enrolled were 60 patients scheduled for receiving selective lumbar surgery at the Department of Spinal Orthopedics, First Hospital Affiliated to Guangzhou University of Traditional Chinese Medicine during October 2009 to June 2010. They were equally randomized into two groups, the trial group and the control group. LI was given to patients in the trial group by intravenous dripping at the dose of 2 mg/kg 30 min before autologous blood collection. The LI (at the final concentration of 0.005%) was added in the heparin saline solution and the washing saline for recycle blood. No LI was given to patients in the control group. They received the same treatment of the trial group. The operation time, the amount of blood loss and blood transfusion were recorded. Patients' venous blood samples were collected for determining cytokines including interleukin-2 (IL-2), interleukin-10 (IL-10), interferon-gamma (IFN-gamma) by ELISA and calculating IL-2/IL-10 ratio before surgery (T1), 1 h (T2), 1 day (T3), and 5 days (T4) after ABT. RESULTS: There was no statistical difference in the amount of blood loss and blood transfusion, the levels of IL-2, IL-10, IFN-gamma, or IL-2/IL-10 at T1 between the two groups (P>0.05). Compared with T1 of the same group, the level of IL-2 decreased at T(2-4), IL-10 increased and IL-2/IL-10 decreased at T(2-3) in the two groups. The level of IFN-gamma decreased at T(2-4), IL-2/IL-10 increased at T4, the level of IL-10 decreased at T4 in the control group (P<0.05, P<0.01). The level of IL-10 decreased at T4 in the trial group with statistical difference (P<0.05, P<0.01). Compared with the control group, the level of IL-2, IFN-gamma, and IL-2/IL-10 at T(2-4) were obviously higher in the trial group. But the IL-10 level was lower in the trial group than in the control group at T(2-4) (P<0.05, P<0.01). CONCLUSION: The application of LI in ABT had regulatory effects on the balance of cytokines.

Ultrasound measurements for evaluation of changes in upper airway during anaesthesia induction and prediction difficult laryngoscopy: a prospective observational study.

Upper airway collapsibility after anaesthesia induction may be associated with unpredictable difficult airway. However, most works on airway anatomy are tended to morphological description before anaesthesia. This study aimed to evaluate the changes of upper airway after anaesthesia induction and using pre-anesthetic ultrasound measurements to predict Difficult Laryngoscopy (DL). We included 104 eligible subjects with complete data, who were performed tracheal intubations under general anaesthesia in the study. The upper airway changes before and after anaesthesia induction were determined by seven neck ultrasound measurements, included as follow: (1) Distance from skin to under surface of Tongue (DT), (2) Thickness of the thickest part of Tongue body (TT), (3) Hyoid Mental Distance (HMD), (4) Depth of Hyoid (DH), (5) Width of Hyoid (WH), (6) Distance from Skin to Epiglottis (DSE), (7) Depth of the anterior combination of the Vocal Cords (DVC). DL was evaluated with Cormack-Lehane (CL). Data regarding HMD [from 45.3 (42.4-48.5) to 41.1 (38.5-44.9) mm], DH [from 8.7 (6.6-10.9) to 7.0 (5.3-9.1) mm], DSE [from 20.1 (16.6-22.5) to 19.5 (16.5-21.6) mm] and the DVC [from 7.1 (5.7-8.3) to 6.8 (5.7-7.9) mm] were decreased (P < 0.05), while the DT [from 15.9 (13.1-18.4) to 17.4 (14.5-19.8) mm] was increased (P > 0.05) after anaesthesia induction. Additionally, when cut-off value of DSE was 21.25 mm before anaesthesia, it may be better predicted to DL [sensitivity 80.0% (95% CI: 60.7-91.6%) and specificity 83.8% (95% CI: 73.0-91.0%)]. The upper airway after induction showed the propensity of collapsibility by ultrasound measurements. Compared with other indicators, the DSE assessed by ultrasound might be considered to a valuable predictor of DL.Trial registration: The study was registered in ClinicalTrials.gov on 23th Jan 2019, ChiCTR1900021123.

Comparison of Various Regional Analgesia Methods for Postoperative Analgesic Effects in Video-assisted Thoracoscopic Surgery: A Systematic Review and Network Meta-analysis.

BACKGROUND: The optimal analgesia for video-assisted thoracoscopic surgery (VATS) is still unknown. OBJECTIVES: Our aim was to conduct a network meta-analysis and systematic review to compare the efficacy of different analgesic strategies in VATS. STUDY DESIGN: Bayesian network meta-analysis. METHODS: We searched PubMed, Embase, Medline, Springer, Google Scholar, and Web of Science to evaluate all relevant randomized controlled trials that investigated the analgesic effects of different regional analgesia methods for VATS published through July 2021. After a comprehensive search of electronic databases, the following methods were identified: epidural analgesia (EA), local anesthetics (LA), superficial serratus anterior plane block (SSAPB), deep serratus anterior plane block (DSAPB), erector spinae plane block (ESPB), paravertebral block (PVB), and intercostal nerve block (ICNB). Primary outcomes were the visual analog scale score at rest, at 2 hours, 6 hours and 24 hours postoperatively. The secondary outcomes were postoperative analgesic consumption, incidence of nausea and emesis, and pruritus. RESULT: Overall, 35 trials met our inclusion criteria. EA and PVB were relatively more advantageous in terms of analgesic effect at 2 hours and 6 hours postoperatively; the EA group was superior to the DSAPB, ESPB, and ICNB groups at 24 hours postoperatively. EA was found to be superior to other analgesia techniques for 24 hour postoperative analgesic consumption., PVB showed advantages in reducing postoperative nausea, emesis, and pruritus. LIMITATIONS: Different concentrations and volumes of local anesthetics might affect the analgesic effects of the various analgesia techniques. CONCLUSION: EA and PVB have certain advantages in analgesia, but the incidence of postoperative pruritus after EA is higher. At the same time, considering the risk of coagulation and puncture complications, PVB may be a better choice.

[Effect of ligustrazine on T-lymphocyte immunity in patients undergoing autologous blood transfusion].

OBJECTIVE: To evaluate the protective effect of ligustrazine on T-lymphocyte immunity of patients undergoing autologous blood transfusion (ABT). METHODS: Forty American Society of Anesthesiologist (ASA) I - II patients scheduled for receiving selective lumbar surgery, with pre-operational anticipatory blood loss > 400 mL and without any diseases of blood or endocrinal system were enrolled. They were equally randomized into two groups, the trial group and the control group. Ligustrazine was given to patients in the trial group by intravenous dripping at the dose of 2 mg/kg, 30 min before auto-blood collection, also by mixed in the washing saline and heparinized saline solution to make the final concentration of ligustrazine 0.005%. No ligustrazine was given to patients in the control group. The amount of blood loss and autotransfused were measured and recorded; and patients' venous blood samples for T-lymphocyte subsets (CD3, CD4, CD8) determination and CD4/CD8 ratio calculation were collected at different time points, i. e. before surgery (T0) and at 1 h (T1), 1st day (T2) and 5th day (T3) after ABT. RESULTS: CD3 decreased obviously at T1 and T2 in both groups (P < 0.05 or P < 0.01), while at T3, it restored to baseline in the trial group, but remained at the low level in the control group (P < 0.05). Moreover, levels of CD3 at T1-T3 were lower in the control group than those in the trial group respectively (P < 0.05 or P < 0.01). CD4 decreased obviously at T1 (P < 0.01) in both groups, it recovered at T2 in the trial group, but the recovering in the control group was T3, so comparison of CD4 level between groups showed significant difference at T1 and T2 (P < 0.05 or P < 0.01). As for CD4/CD8 ratio, it decreased obviously at T2 and T3 in the control group (P < 0.05), but unchanged in the trial group, showing statistical difference between groups (P < 0.05). CONCLUSION: Ligustrazine had definite protective effect on T-lymphocyte immunity in patients undergoing ABT, which was presented by the milder inhibition and quicker recovery of immunity.

A systematic review and meta-analysis of the safety and efficacy of remifentanil and dexmedetomidine for awake fiberoptic endoscope intubation.

BACKGROUND: Awake fiberoptic endoscope intubation (AFOI) is the primary strategy for managing anticipated difficult airways. Adequate sedation, most commonly being achieved with remifentanil and dexmedetomidine, is integral to this procedure. This meta-analysis aimed to compare the safety and efficacy of these 2 sedatives. METHODS: We conducted electronic searches in Embase, Web of Science, PubMed, Google Scholar, Medline, Springer, and Web of Science with no language restrictions. Studies comparing safety and efficacy between the sole use of remifentanil and dexmedetomidine among patients who underwent AFOI were included. Eight randomized controlled trials, comprising 412 patients, met the inclusion criteria. The primary outcomes were first attempt intubation success rate and incidence of hypoxia. The secondary outcomes were the Ramsay Sedation Scale score at intubation, memory recall of endoscopy, and unstable hemodynamic parameters during intubation. RESULTS: Dexmedetomidine significantly reduced the incidence of hypoxemia during AFOI (risk ratio: 2.47; 95% confidence [CI]: 1.32-4.64]) compared with remifentanil; however, the first intubation success rates were equivalent (risk ratio: 1.12; 95% CI: 0.87-1.46]. No significant differences between the 2 sedatives were found for the Ramsay Sedation Scale score at intubation (mean difference: -0.14; 95% CI: -0.66-0.38) or unstable hemodynamic parameters during intubation (risk ratio: 0.83; 95% CI: 0.59-1.17). Dexmedetomidine reduced memory recall of endoscopy (risk ratio: 1.39; 95% CI: 1.13-1.72). CONCLUSIONS: While both remifentanil and dexmedetomidine are effective for AFOI and well-tolerated, dexmedetomidine may be more effective in reducing the incidence of hypoxemia and memory recall of endoscopy. PROSPERP REGISTRATION NUMBER: CRD42020169612.

Managing the difficult airway: A survey of doctors with different seniority in China.

ABSTRACT: Although equipment and human resources are vital elements of difficult airway management (DAM). But the approach and practice of DAM are more important. So, we conducted the present survey to address anesthesiologists of different working years in this knowledge gap.This nationwide cross-sectional study was conducted from October 27, 2016 to November 27, 2016. The survey was completed online in New Youth Anesthesia Forum including DAM assessment, anticipated and unanticipated DAM, difficult airway algorithm, use of the front of neck access (FONA) technique and training, DAM outside the operation room, and difficult extubation management.We received 1935 replies (44%). Mouth opening and Mallampati classification were the most common methods to evaluate difficult airways. When suffering from unanticipated difficult airway 63% less than 10 years anesthesiologists (LA) and 65% more than 10 years anesthesiologists (MA) would ask for help after trying 1 to 2 times (P = .000). More than 70% of LA and MA respondents reported preferring cannula cricothyrotomy to deal with emergency airway, 507 (41.6%) MA respondents reported that they used FONA techniques to save patients' lives (P = .000). Nearly 70% respondents worried full stomach when intubated outside operation room and more than 80% respondents selected auscultation to identify the placement. More than 80% respondents had not used Bougie to assist extubation. A 73.2% respondents know ABS algorithm and 96.4% know Chinese airway expert consensus among MA respondents, this was significant to LA respondents (P = .000).The respondents in the LA and MA have a training gap in their evaluation of difficult airways, trained and used FONA emergency skills, facilitated of the airway guidelines at home and abroad. Also, we should provide more airway theory and skill training to our young doctors to advanced airway skills.

Comparison of tracheal intubation between sitting position and standing position in COVID-19 patients: A manikin study.

ABSTRACT: It is recommended to use visual laryngoscope for tracheal intubation in a Corona Virus Disease 2019 patient to keep the operator farther from the patient. How the position of the operator affects the distance in this setting is not ascertained. This manikin study compares the distances between the operator and the model and the intubation conditions when the operator is in sitting position and standing position, respectively.Thirty one anesthesiologists with minimum 3-years' work experiences participated in the study. The participant's posture was photographed when he performed tracheal intubation using UE visual laryngoscope in standing and sitting position, respectively. The shortest distance between the model's upper central incisor and operator's face screen (UF), the horizontal distance between the model's upper central incisor and the operator's face screen, the angle between the UF line and the vertical line of the model's upper central incisor were measured. The success rate of intubation, the duration of intubation procedure, the first-attempt success rate, the Cormack-Lehane grade, and operator comfort score were also recorded.When the operator performed the procedure in sitting position, the horizontal distance between the model's upper central incisor and the operator's face screen distance was significantly longer (9.5 [0.0-17.2] vs 24.3 [10.3-33.0], P ≤ .001) and the angle between the UF line and the vertical line of the model's upper central incisor angle was significantly larger (45.2 [16.3-75.5] vs 17.7 [0.0-38.9], P ≤ .001). There was no significant difference in UF distance when the operator changed the position. Cormack-Lehane grade was significantly improved when it was assessed using visual laryngoscope. Cormack-Lehane grade was not significantly different when the operator assessed it in sitting and standing position, respectively. No significant differences were found in the success rate, duration for intubation, first-attempt success rate, and operator comfort score.The operator is kept farther from the patient when he performs intubation procedure in sitting position. Meanwhile, it does not make the procedure more difficult or uncomfortable for the operator, though all the participants prefer to standing position.

[Effect of shenfu injection on the stability of circulation during induction of general anesthesia for aged people].

OBJECTIVE: To observe the intervention of Shenfu Injection (SFI) on the hemodynamics and circulatory function during induction of general anesthesia for aged people, in order to optimize the medication of anesthesia inductive phase in aged people. METHODS: Sixty aged patients scheduled to receive general anesthesia were equally randomized into 2 groups, the SFI group and the control group. SFI via intravenous drip (1 mL/kg diluted with 5 mL/kg saline) was administered to the SFI group 15 min before anesthesia induction and to the control group, normal saline was administered instead. Then the induction and intubation were implemented. The systolic blood pressure (SBP), diastolic pressure (DBP), heart rate (HR), central venous pressure (CVP), pulse saturation oxygen (SpO2), and the ST segment of ECG were observed at the different time points of induction, i.e. at the time of entry into the operating room (T1), ending the medication (T2), before the induction (T3), showing the lowest SBP in induction (T4), before and after intubation (T5 and T5). The dose and frequency of atropine and ephedrine applied in the inductive phase were observed as well. RESULTS: As compared with the baseline values measured at T1, CVP elevated at T2, T3, and T6 (P < 0.05), SBP and DBP descended at T4, T5, T6 in both groups; HR accelerated at T2, T3, and T6 in the control group; and HR at T4, T5 and T6 in both groups were significantly different (P < 0.05 or P < 0.01). Inter-group comparisons showed significant difference between groups in CVP at T2 (P < 0.05); so did SBP, DBP and HR at T4, T5 and T6 (P < 0.05 or P < 0.01). CONCLUSION: Application of SFI in the inductive phase of general anesthesia in aged people could evidently reduce the fluctuation of hemodynamics to prevent the occurrence of myocardial ischemia and improve it definitely.

The use of ETView endotracheal tube for surveillance after tube positioning in patients undergoing lobectomy, randomized trial.

The ETView tracheoscopic ventilation tube (TVT) is a tracheal tube (TT) incorporating a video camera and a light source in its tip. The view from the tip appears continuously on a portable monitor in the anesthesia area. We evaluated the effectiveness and usefulness of the single/double ETView TVT in monitoring the tracheal tube position during general anesthesia undergoing video-assisted thoracoscopic lobectomy.Eighty-three patients with pulmonary bullae (American Society of Anesthesiologists (ASA) I-III) undergoing lobectomy, with general anaesthesia, were included. Patients were randomly assigned to 3 groups, based on the tube ETView double-lumen tube (VDT), ETView single-lumen tube (VST), or traditional double lumen tube (DT).All 83 patients' intubations were successful to achieve 1-lung ventilation: 74 patients at the first attempt (22/26 in VDT, 26/28 in VST, 26/29 in DT group) and 9 patients at the second attempt. The time to achieve 1-lung ventilation with the VDT was 58.5 ±â€Š21.5 (mean ±â€ŠSD) seconds, the VST was 38.2 ±â€Š10.1 (mean ±â€ŠSD) seconds, and the DT group was 195.5 ±â€Š40.3 (mean ±â€ŠSD) seconds. During operations, the ETView tubes provided continuous airway visualization in all patients; a good view was obtained in 24/25 patients in VDT/VST, moderate in 4/12 patients in VDT/VST, and poor in 1/1 patients in VDT/VST. When the patient left the postanesthesia care unit, all had sore throat and 26/15/25 patients in VDT/VST/DT group had hoarseness. All had good outcomes of the surgical operations.We found the ETView tube to be helpful in the endotracheal intubation and continuous surveillance of tube position in patients with video-assisted thoracoscopic lobectomy. The ETView single lumen endotracheal tube had fewer associated complications and is superior to the 2 double-lumen tubes.

[Changes in hemodynamics and nitric oxide/endothelin-1 during liver transplantation in patients with cirrhosis].

OBJECTIVE: To study the systemic and pulmonary hemodynamic changes of patients with cirrhosis during liver transplantation and evaluate the role of nitric oxide (NO) and endothelin-1(ET-1). METHODS: Twenty-four patients with cirrhosis at terminal stage underwent modifying piggy-back liver transplantation. Hemodynamic parameters including cardiac index (CI), arterial blood pressure (ABP) and pulmonary arterial pressure (PAP) were monitored continuously. NO and ET-1 levels were measured by radioimmunoassay. Blood samples were obtained from superior vena cava at induction of anesthesia (T1), 10 minutes before vascular cross clamping (T2), 30 minutes after vascular cross clamping (T3), 30 minutes after reperfusion of the new liver (T4), and at the end of surgery (T5). RESULTS: (1) Mean arterial blood pressure (MABP) lowered significantly in the early stage of anhepatic period and neohepatic period (P<0.05 or P<0.01). (2) Central venous pressure (CVP), mean pulmonary arterial pressure (MPAP) and pulmonary arterial wedge pressure (PAWP) lowered significantly during anhepatic period. They rose significantly after graft reperfusion, and remained at a high level with respect to the baseline level (P<0.05). (3) CI declined significantly during anhepatic period and increased 10 minutes after reperfusion of new liver. (4) Systemic vascular resistance index and pulmonary vascular resistance index increased during anhepatic period and were higher than the baseline level 15 minutes after reperfusion. SVRI was lower than baseline level 30 minutes after reperfusion. (5) Compared with the baseline level, NO decreased significantly after vascular cross-clamping and elevated 30 minutes after reperfusion. ET levels were significant elevated 30 minutes after clamping and after reperfusion (P<0.05). CONCLUSION: Significant hemodynamic changes occur in patients with cirrhosis during liver transplantation, and pulmonary hypertension develops during neohepatic period. The role of elevated contents of NO and ET-1 after reperfusion needs further study.

[Changes in pulmonary gas exchange and intrapulmonary shunt during orthotopic liver transplantation with non-venovenous bypass].

OBJECTIVE: To study the changes in pulmonary gas exchange and intrapulmonary shunt during orthotopic liver transplantation (OLT) with non-venovenous bypass. METHODS: Nineteen American Society of Anesthesiologists (ASA) III-IV patients (male 17, female 2) with terminal liver diseases were enrolled for study. Their age ranged from 25-67 years. Anesthesia was induced with midazolam 0.05 mg/kg, propofol 0.5-1.0 mg/kg, fentanyl 4 microg/kg, with vecuronium 0.1 mg/kg, and it was maintained with isoflurane inhalation, fentanyl and vecuronium. All patients were mechanically ventilated with 100% O(2) during operation. After induction of anesthesia, Swan-Ganz catheter was inserted via right internal jugular vein. Cardiac output (CO), mixed venous oxygen saturation and core venous temperature were continuously monitored with continuous cardiac output monitor, and electrocardiogram (ECG), central venous pressure (CVP), pulmonary arterial wedge pressure (PAWP), pulse oxygen saturation (SpO(2)) and end-tidal carbon dioxide tension (P(ET)CO(2)) were also continuously monitored during operation. Radial artery was cannulated for continuous direct blood pressure monitoring. Arterial and mixed venous blood samples were taken after induction of anaesthesia, and partial pressure of oxygen (PaO(2)), partial pressure of carbon dioxide (PaCO(2)), and cardiac index(CI) were determined after induction of anaesthesia, 30 minutes before anhepatic stage, 30 minutes during anhepatic stage, 30 minutes during neohepatic stage and at the end of operation. Alveolar-arterial oxygen partial pressure difference (P(A-a)O(2)) and intrapulmonary shunt (Qs/Qt) were calculated according to the standard formula. RESULTS: After induction of anaesthesia, when the inspired oxygen flow (FiO(2)) was 1.00, PaO(2) was only (385.0+/-56.4) mm Hg (1 mm Hg=0.133 kPa), P(A-a)O(2) and Qs/Qt were all higher than normal values. There were no significant changes 30 minutes before anhepatic stage as compared with that after induction of anaesthesia. CO, CI and Qs/Qt were decreased significantly during anhepatic stage compared with that after induction of anaesthesia. PaO(2), PaCO(2), CO and CI were increased and P(A-a)O(2) decreased significantly, but there were no significant changes in Qs/Qt 30 minutes during neohepatic stage. CI and CO increased and Qs/Qt decreased significantly at the end of operation, but there were no significant difference in PaO(2), PaCO(2) and P(A-a)O(2). CONCLUSION: There are obvious changes in pulmonary gas exchange and intrapulmonary shunt during OLT with non-veno-venous bypass.

Comparison between remifentanil and dexmedetomidine for sedation during modified awake fiberoptic intubation.

Cricothyroid membrane injections and the application of a coarse fiberoptic bronchoscope (FOB) below the vocal cords for topical anesthesia have a number of limitations for certain patients. Thus, the aim of the present observational study was to assess the effect of a novel modified topical anesthesia method using the effective sedation drugs, remifentanil (Rem) or dexmedetomidine (Dex), during awake fiberoptic orotracheal intubation (AFOI). In total, 90 adult patients, who had been classified as American Society of Anesthesiologists I-II, were included in the study. The patients had anticipated difficult airways and were to undergo orotracheal intubation for elective surgery. The patients were enrolled in the double-blinded randomized pilot study and received Rem or Dex for sedation during the modified AFOI procedure. The two groups received 2% lidocaine for topical anesthesia via an epidural catheter, which was threaded through the suction channel of the FOB. The main clinical outcomes were evaluated by graded scores representing the conditions for intubation and post-intubation. Additional parameters analyzed included airway obstruction, hemodynamic changes, time required for intubation, amnesia level and subjective satisfaction. All 90 patients were successfully intubated using the modified AFOI technique. The comfort scores and airway events during intubation did not significantly differ between the two groups. However, the Rem group experienced less coughing, and less time was required for tracheal intubation when compared with the Dex group. No statistically significant differences were observed in the changes to the mean arterial pressure and heart rate at any time point between the two groups. Therefore, the current study demonstrated that the modified AFOI method is feasible and effective for difficult airway management, and that Dex and Rem exhibit similar efficacy as adjuvant therapies.