Influence of three different anesthesia protocols on aged rat brain: a resting-state functional magnetic resonance imaging study / 中华医学杂志(英文版)

BACKGROUND@#Resting-state functional magnetic resonance imaging (rs-fMRI) is a promising method for the study of brain function. Typically, rs-fMRI is performed on anesthetized animals. Although different functional connectivity (FC) in various anesthetics on whole brain have been studied, few studies have focused on different FC in the aged brain. Here, we measured FC under three commonly used anesthesia methods and analyzed data to determine if the FC in whole brain analysis were similar among groups.@*METHODS@#Twenty-four male aged Wistar rats were randomly divided into three groups (n = 8 in each group). Anesthesia was performed under either isoflurane (ISO), combined ISO + dexmedetomidine (DEX) or α-chloralose (AC) according to the groups. Data of rs-fMRI was analyzed by FC in a voxel-wise way. Differences in the FC maps between the groups were analyzed by one-way analysis of variance and post hoc two-sample t tests.@*RESULTS@#Compared with ISO + DEX anesthesia, ISO anesthesia caused increased FC in posterior brain and decreased FC in the middle brain of the aged rat. AC anesthesia caused global suppression as no increase in FC was observed.@*CONCLUSION@#ISO could be used as a substitute for ISO + DEX in rat default mode network studies if the left temporal association cortex is not considered important.

Geriatric Anesthesia-related Morbidity and Mortality in China: Current Status and Trend / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>The population of elderly patients and the amount of geriatric anesthesia have been growing rapidly in China. Thus, understanding the morbidity and mortality associated with geriatric anesthesia in China is critical to the improvement of anesthesia quality and outcome. The aim of the review was to discuss the geriatric anesthesia-related morbidity and mortality in China, as well as to point out the future trend.</p><p><b>DATA SOURCES</b>Articles in this review were all searched from Wanfang, China National Knowledge Infrastructure (CNKI), VIP, PubMed, and Web of Science databases, based on the reports originated in China from January 2011 to December 2016.</p><p><b>STUDY SELECTION</b>A total of 57 studies were selected for further study, including 12 retrospective studies, 35 prospective studies, 3 meta-analyses, 4 reviews, 1 viewpoint, and 2 case reports. Of the total studies, 42 studies were in Chinese while 15 were in English.</p><p><b>RESULTS</b>The mortality and morbidity associated with geriatric anesthesia in China are not yet completely reported. Some factors have been recognized, while some are yet to be identified and confirmed. Several studies addressed postoperative cognitive dysfunction and postoperative delirium, whereas only a few studies can be found on renal complications. Thus, a nationwide registry is essential for geriatric anesthesia-associated adverse outcomes. The mortality associated with geriatric anesthesia in China should be reported promptly. In the future, the perspective of geriatric anesthesia needs to be expanded into perioperative geriatric medicine to improve the perioperative management strategy based on the postoperative outcome-directed concept transformation.</p><p><b>CONCLUSIONS</b>Anesthesiologists should evaluate the physiological and medical status and focus on the prevention of potential complications in the perioperative setting with the goal to enhance elderly patients' long-term well-being and survival quality.</p>

Protective Effect of Low-dose Sevoflurane Inhalation and Propofol Anesthesia on the Myocardium after Carotid Endarterectomy: A Randomized Controlled Trial / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Myocardial infarction is an important cause of mortality after carotid endarterectomy (CEA). Sevoflurane provides myocardial protection to patients undergoing coronary surgery, but whether it also reduces the incidence of myocardial injury in CEA patients is unclear. In this study, we evaluated the cardioprotective effect of low-dose sevoflurane with propofol in patients undergoing CEA.</p><p><b>METHODS</b>This was a single-center, prospective, randomized study conducted between November 2011 and December 2013. The study population of 122 patients who underwent CEA were randomly assigned to two groups. Group A (n = 62) received propofol for anesthetic maintenance, and Group B (n = 60) additionally received 0.8% end-tidal sevoflurane. The bispectral index was kept at 40-60. Myocardial injury, defined as cardiac troponin I (cTnI) levels >0.04 ng/ml, was the primary end-point. Levels of cTnI were measured before anesthesia, and at 4, 24, and 72 h after surgery. Perioperative hemodynamic parameters and adverse cardiovascular events after surgery were also recorded.</p><p><b>RESULTS</b>Myocardial injury was detected in 18 patients in Group A and 7 in Group B. The difference was statistically significant (29.0% vs. 11.7%, P = 0.018). The hemodynamic parameters were comparable between the groups, as were adverse cardiovascular events (P = 0.619).</p><p><b>CONCLUSIONS</b>Low-dose sevoflurane inhalation along with propofol reduces the incidence of myocardial injury in symptomatic patients after CEA.</p>

Goal-directed Fluid Therapy May Improve Hemodynamic Stability of Parturient with Hypertensive Disorders of Pregnancy Under Combined Spinal Epidural Anesthesia for Cesarean Delivery and the Well-being of Newborns / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Hypotension induced by combined spinal epidural anesthesia in parturient with hypertensive disorders of pregnancy (HDP) can easily compromise blood supply to vital organs including uteroplacental perfusion and result in fetal distress. The aim of this study was to investigate whether the goal-directed fluid therapy (GDFT) with LiDCO rapid system can improve well-being of both HDP parturient and their babies.</p><p><b>METHODS</b>Fifty-two stable HDP parturient scheduled for elective cesarean delivery were recruited. After loading with 10 ml/kg lactated Ringer's solution (LR), parturient were randomized to the GDFT and control group. In the GDFT group, individualized fluid therapy was guided by increase in stroke volume (ΔSV) provided via LiDCO rapid system. The control group received the routine fluid therapy. The primary endpoints included maternal hypotension and the doses of vasopressors administered prior to fetal delivery. The secondary endpoints included umbilical blood gas abnormalities and neonatal adverse events.</p><p><b>RESULTS</b>The severity of HDP was similar between two groups. The total LR infusion (P < 0.01) and urine output (P < 0.05) were higher in the GDFT group than in the control group. Following twice fluid challenge tests, the systolic blood pressure, mean blood pressure, cardiac output and SV in the GDFT group were significantly higher, and the heart rate was lower than in the control group. The incidence of maternal hypotension and doses of phenylephrine used prior to fetal delivery were significantly higher in the control group than in the GDFT group (P < 0.01). There were no differences in the Apgar scores between two groups. In the control group, the mean values of pH in umbilical artery/vein were remarkably decreased (P < 0.05), and the incidences of neonatal hypercapnia and hypoxemia were statistically increased (P < 0.05) than in the GDFT group.</p><p><b>CONCLUSIONS</b>Dynamic responsiveness guided fluid therapy with the LiDCO rapid system may provide potential benefits to stable HDP parturient and their babies.</p>

Evaluation of entropy for monitoring the depth of anesthesia compared with bispectral index: a multicenter clinical trial / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>As a new electroencephalogram (EEG) signal processing technique for monitoring the depth of anesthesia, entropy consists of two indices: reaction entropy (RE) and state entropy (SE). Our study compared entropy with classical bispectral index (BIS) in reduction of myoelectrical interference and noxious stimuli with EEG signals.</p><p><b>METHODS</b>Two hundred and eighty patients (ASA I-II, 18-60 years old) undergoing scheduled surgeries from seven medical centers were enrolled. Anesthesia induction was managed with propofol via the target-controlled infusion (TCI) system. The results of BIS, RE, SE, mean arterial pressure (MAP) and heart rate (HR) were recorded before anesthesia induction, at the moment of unconsciousness, before and 2 minutes after administration of muscle relaxant, and before and one and three minutes after the tracheal intubation.</p><p><b>RESULTS</b>The values of half maximum effective concentrations (EC50), 5% effective concentrations (EC05) and 95% effective concentrations (EC95) of propofol effect-site concentration at the onset of unconsciousness were 1.2 (1.1-1.3 µg/ml), 2.5 (2.4-2.5 µg/ml) and 3.7 (3.7-3.8 µg/ml), while those of the predicted plasma propofol concentration were 2.8 (2.7-2.9 µg/ml), 3.9 (3.8-3.9 µg/ml) and 4.9 (4.8-5.0 µg/ml), respectively. The values of BIS, SE and RE were 62, 59 and 63 when 50% of patients lost consciousness, and 79, 80, 85 and 42, 37, 44, respectively, when 5% and 95% of patients were unconscious. The values of BIS, RE and SE dropped two minutes after the injection of muscle relaxant, but there were no significant differences between RE and SE. MAP and HR increased visibly, which indicated a reaction to tracheal intubation; the values of BIS, RE and SE, however, did not display any significant changes.</p><p><b>CONCLUSIONS</b>This large-sample multicentric study confirmed the values of RE and SE as approximating BIS value, at the onset of unconsciousness during propofol TCI anesthesia. After elimination of myoelectrical activation, all values of RE, SE and BIS decreased significantly and the three indices were less sensitive to noxious stimuli than cardiovascular responses.</p>

Ultrasound facilitates identification of combined spinal-epidural puncture in obese parturients / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The palpation method is widely used in clinical practice to identify the puncture site of combined spinal-epidural (CSE) blocks, but it is usually difficult to accurately locate the puncture site in obese parturients. Accurate identification of the puncture site is crucial for successful CSE block. The objective of this study was to evaluate the impact of ultrasound imaging on the success rate of CSE puncture in obese parturients.</p><p><b>METHODS</b>Sixty obese parturients with a body mass index ≥ 30 kg/m(2) who were scheduled for caesarean section were randomized into two equal-sized groups for location of the puncture site: an ultrasound group and a palpation group. The success rate of puncture at the first puncture site, the number of puncture attempts, duration of CSE procedure, time taken to determine the puncture site, and the depth of the epidural space were compared between groups. The frequencies of complications such as puncture site hemorrhage, neurological damage, and inadvertent dural puncture were also studied.</p><p><b>RESULTS</b>There were no differences in age, body weight, height, body mass index, or gestational age between the two groups. The success rate of puncture at the first puncture site was significantly higher in the ultrasound group than the palpation group (100.00% vs. 70.00%, P = 0.004). The number of puncture attempts was significantly lower in the ultrasound group than the palpation group (χ(2) = 6.708, P = 0.035). The time taken for determining the puncture site was (0.30 ± 0.12) minutes in the palpation group and (2.60 ± 0.61) minutes in the ultrasound group (P < 0.001). The duration of CSE procedure was (7.67 ± 1.52) minutes in the palpation group and (9.37 ± 1.35) minutes in the ultrasound group (P < 0.001). The depth of the epidural space was similar in both groups (P = 0.586). Puncture site hemorrhage was observed in 6 (20.00%) patients in the palpation group and 2 (6.67%) patients in the ultrasound group (P = 0.255).</p><p><b>CONCLUSIONS</b>Ultrasound imaging improves the rate of successful puncture at the first puncture site and decreases the number of puncture attempts. It facilitates CSE puncture in obese parturients.</p>

Effect of nicardipine combined with esmolol on systemic and tissue oxygenation during off-pump coronary artery bypass grafting surgery / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The hemodynamics and oxygenation severely fluctuated during the off-pump coronary artery bypass grafting (OPCABG). This study aimed at investigating whether or not nicardipine combined with esmolol (1:10) can maintain systemic and tissue oxygenation during OPCABG.</p><p><b>METHODS</b>Twenty patients scheduled for OPCABG were divided ramdomly into Group nicardipine (N) and Group nitroglycerine (X) respectively combined with esmolol (E) (Dosage ratio: 1 to 10) (Group N + E and Group X + E) with 10 patients in each group. The mixed solution of N + E or X + E were titrated to maintain mean arterial blood pressure between 70 and 80 mmHg following anesthesia induction. The variables of hemodynamics, arterial blood lactate content (Lac) and gastric intramucosal partial pressure of carbon dioxide were measured at the following time points: after induction of anesthesia (T1), pre-revascularization (T2), grafting of left anterior descending (T3), right coronary descending (T4) and left coronary circumflexus branches (T5), post-revascularization (T6), the end of operation (T7). The delivery of oxygen (DO2), consumption of oxygen (VO2) and gastric intramucosal pH (pHi) were calculated.</p><p><b>RESULTS</b>The cardiac index (CI) in Group N + E was significantly increased (P < 0.05) as compared with T1 during OPCABG, while it was mildly decreased in Group X + E. The stroke volumes at T4, T5 in Group N + E and at T3-T6 in Group X + E were significantly decreased (P < 0.05). The systemic vascular resistance indices in Group N + E were significantly decreased as compared with T1 (P < 0.05). The heart rates in these two Groups were significantly elevated intraoperatively (P < 0.05). The DO2 after the infusion of N + E was significantly increased (P < 0.05) or leveled to T1, and the Lac were within the normal range. But the DO2 in Group X + E was decreased throughout the procedure, reaching significant level at T5 (P < 0.05), and the Lac was significantly increased beyond normal range (P < 0.05). The pHi in Group N + E was maintained above 7.35 during OPCABG, while it was less than 7.35 from T4 to T7 in Group X + E.</p><p><b>CONCLUSION</b>Nicardipine combined with esmolol (1:10) regimen may maintain systemic and tissue oxygenation during OPCABG.</p>