胸段硬膜外麻醉复合全麻对开胸单肺通气患者氧代谢的影响

目的 通过比较吸入全身麻醉和吸入全麻复合胸段硬膜外麻醉对开胸手术的血液动力学和血气分析的变化,探讨硬膜外麻醉对全身氧代谢的影响。方法 20例因食管癌需开胸单肺通气手术患者,根据麻醉方法的不同随机分为异氟醚吸入全麻组(GI组)和异氟醚吸入复合硬膜外组(GIE组)。每组各10例。GI组采用异氟醚/芬太尼/维库溴铵麻醉。GIE组采用异氟醚/维库溴铵/胸部硬膜外0.5％罗哌卡因麻醉。连续监测平均动脉压(MAP)、心排指数(CI)、心率(HR)、中心静脉压(CVP)、外周血管阻力(SVRI)。分别于清醒时,侧卧双肺通气30 min,单肺通气15、30、60和120 min,侧卧再次双肺通气30 min抽取动脉,混合静脉血血样,测定血气,并计算氧供(DO2)、氧耗(VO2),以及氧供氧耗比(DO2/VO2)。结果 GIE组MAP低于GI组(P<0.05),SVRI不但低于GI组,也低于基础值(p<0.05)。单肺通气后30、60、120 min两组CI均高于基础值(P<0.05),GIE组各时间点CI与GI组比较差异无显著性(P>0.05)。两组各时间点DO2差异无显著性(P>0.05)。单肺通气15、30和60min时GIE组SvO2明显低于GI组(P<0.05),而VO2明显高于GI组(P<0.05),同时DO2/VO2明显低于GI组(P<0.05)。结论 以单纯全麻相比,胸段硬膜外联合全麻可能会使单肺通气早期全身氧耗增加,DO2/VO2降低。     

Effects of upper thoracic epidural anesthesia on hemodynamics and oxygen supply-demand relationship in hypovolemic dogs]

The purpose of the present study is to assess the influence of upper thoracic epidural anesthesia (TEA) on hemodynamics, the systemic oxygen supply-demand relationship, and several indications of stress in the presence of preexisting hypovolemia. Sixteen adult mongrel dogs were anesthetized with halothane and nitrous oxide, and blood was withdrawn at the rate of 3 ml.kg-1.min-1 for 10 min. The dogs were randomly assigned to two groups; one receiving TEA (TEA group, n = 8), and the other without (controls, n = 8). Mean arterial blood pressure, heart rate, arterial concentrations of epinephrine and norepinephrine remained significantly lower (P less than 0.05) in the TEA group than in the controls during the 100-min observation period following the start of TEA. Cardiac index, oxygen supply-demand ratio (O2 delivery/O2 consumption) and arterial lactate concentration showed no significant intergroup differences at any point during observation. By contrast, there was a significant difference in arterial pH between the TEA group (7.22 +/- 0.05, mean +/- SD) and the controls (7.15 +/- 0.08) after 100 min of TEA. These results indicate that in hypovolemic dogs anesthetized with halothane and nitrous oxide, TEA affects the acid-base balance favorably without significantly influencing the systemic oxygen supply-demand relationship.     

Severe hemodynamic deterioration during epidural anesthesia for endovascular treatment of thoracic aortic stenosis

A 72-year-old woman diagnosed with critical descending aortic stenosis was scheduled for endovascular treatment by angioplasty and implantation of an aortic stent. Her medical history included arterial hypertension, lipid metabolic disorder, obesity, Takayasu disease, dermatopolymyositis, and alleged allergy to iodine contrast and local anesthetics. After the allergies were ruled out, it was decided to use a regional anesthetic technique to avoid the postoperative complications of general anesthesia and achieve better hemodynamic control during surgery. Surgery was carried out under epidural anesthesia and intravenous sedation. After angioplasty and during self-expansion of the stent, the patient's hemodynamics deteriorated rapidly; she lost consciousness and required orotracheal intubation and immediate resuscitation measures. The literature describes in detail the management of patients with thoracic aortic lesions, including the most appropriate way to provide anesthesia. General anesthesia seems to be preferred, although care is taken to individualize the decision. We analyze this case of a patient with severe thoracic aortic stenosis undergoing endovascular treatment under epidural anesthesia.     

Effects of thoracic epidural anesthesia on myocardial pH and metabolism during ischemia

The effect of thoracic epidural anesthesia (TEA) on the ischemic myocardium was examined in open-chest dogs anesthetized intravenously. Ischemia induced by brief coronary artery occlusion caused an elevation of the ST segment in epicardial ECG and a reduction in myocardial pH and contractile force. TEA with 0.15 ml/kg of 0.4% bupivacaine solution attenuated an ischemia-induced decrease in myocardial pH and an increase of the ST segment in epicardial ECG. This attenuation was maintained even after the restoration of blood pressure and heart rate, which had been decreased significantly after TEA, to pre-TEA levels, suggesting that a beneficial effect of TEA should not be confined to its hemodynamic changes such as decreased blood pressure and heart rate. In contrast, the subendocardial contents of ATP, creatine phosphate (CP) and lactate were not affected by TEA, either in the presence or the absence of 5 min LAD occlusion. These results suggest that neither hemodynamic nor metabolic changes are responsible for the reduced myocardial ischemic acidosis induced by TEA after brief coronary artery occlusion. The acidosis-saving property of TEA is favorable for the ischemic heart.     

上腹部手术中胸段硬膜外麻醉联合全身麻醉对血流动力学的影响

目的 观察胸段硬膜外麻醉联合全身麻醉(TEA+GA)与全凭静脉麻醉(TIVA)这两种麻醉方法在上腹部手术时血流动力学参数的改变.方法 自2007年12月至2008年5月选择44例拟行择期上腹部手术的美国麻醉医师协会(ASA)Ⅱ～Ⅲ级患者,麻醉诱导前行胸段硬膜外穿刺置管.麻醉诱导及气管内插管完成后,持续静脉输注丙泊酚和雷米芬太尼维持静脉麻醉.然后患者被随机双盲分入TEA+GA组(n=22)或TIVA组(n=22).TEA+GA组患者在单次硬膜外腔注入0.25%布比卡因0.2 ml/kg后继以0.2 ml·kg-1·h-1的剂量持续输注;而TIVA组则单次硬膜外腔注入生理盐水后继之持续输注之,其容积和速率与上组相同.监测指标为:心电图、动脉收缩压(SAP)、舒张压(DAP)、平均动脉压(MAP)、心率(HR)、中心静脉压、心指数(CI)、全身血管阻力(SVR)、脉搏氧饱和度和呼气末CO2水平,间断进行血气分析.两组的观测时间均为90 min.结果 在硬膜外腔应用布比卡因或生理盐水后的观察时点,TEA+GA组SAP、DAP、MAP、HR和SVR呈显著性降低;与TIVA组相比,TEA+GA组SAP、DAP、MAP和SVR的降低均具有统计学意义(P≤0.05).但TEA+GA组CI、SV改变不大,与TIVA组相比差异无统计学意义.结论 TEA+GA麻醉中尽管血压呈一定程度下降,但可能与体循环阻力降低有关,而其心功能并未受到明显抑制.提示TEA+GA麻醉方法具有较好的心血管系统稳定性.     

Nonanalgesic effects of thoracic epidural anesthesia

Thoracic epidural anesthesia, which has been performed since the 1950s, has progressed from being one analgesic technique among others to its present status as the technique of choice for managing pain after major abdominal and thoracic surgery. In addition to providing effective analgesia, the epidural infusion of local anesthetic agents produces a sympathetic block that offers advantages over other types of pain control, particularly with respect to the cardiovascular, respiratory, and gastrointestinal systems. Thoracic epidural anesthesia provides dynamic pain relief, allowing the patient to resume activity early. It also permits early extubation and is associated with fewer postoperative pulmonary complications, shorter duration of paralytic ileus, and a better response to the stress of anesthesia and surgery. However, meta-analyses have not yet demonstrated that postoperative outcomes are improved. This review describes the nonanalgesic effects of thoracic epidural anesthesia.     

上胸段硬膜外阻滞对大鼠脑缺血再灌注损伤的作用

目的探讨上胸段硬膜外阻滞(HTEA)对大鼠脑缺血再灌注损伤的作用及可能机制。方法健康雄性Wistar大鼠24只,随机分成3组(n=8)：假手术组(SH组)、缺血再灌注组(I/R组)和HTEA组。采用四血管阻断法制作全脑缺血再灌注损伤模型,缺血20 min。HTEA组在缺血前2 h行HTEA,于T_(4,5)每8 h注入0．125%布比卡因100μl·kg~(-1),直至再灌注72 h处死大鼠,SH组、I/R组给予等量生理盐水。取脑组织,HE染色、免疫组织化学技术和原位末端标记法检测双侧海马CAI区存活细胞数、凋亡细胞及聚腺苷二磷酸核糖聚合酶(PARP)表达。结果脑缺血再灌注可导致海马CAI区存活细胞数下降,凋亡细胞数、PARP表达升高,HTEA可减弱缺血再灌注导致的上述改变。结论HTEA可减轻大鼠脑缺血再灌注损伤。     

A hemothorax after thoracic epidural anesthesia

A case of a hemothorax that occurred after thoracic epidural anesthesia is described. This situation might have been caused by accidental puncture of the intercostal vessel and visceral pleura by a Tuohy needle. The risk of causing a pneumothorax and/or hemothorax must be kept in mind when attempting thoracic epidural anesthesia.     

Effects of lumbar or thoracic epidural anesthesia on median nerve somatosensory evoked potentials

Somatosensory evoked potentials (SSEP) are used increasingly to monitor the integrity of neural pathways in anesthetized patients. To evaluate the influence of epidural anesthesia on the central nervous system, we studied the effects of lumbar or thoracic epidural anesthesia with lidocaine on the median nerve SSEP in 9 patients. The peak latencies (N1, P2, N2) and amplitudes (N1-P2, P2-N2) of the SSEP response over the sensory cortex were recorded before and 15 min after epidural anesthesia. The peak latencies of control and post epidural anesthesia of N1, P1, N2 were 19.2 +/- 1.7 msec, 19.6 +/- 1.6 msec (N1), 24.7 +/- 2.3 msec, 25.7 +/- 2.0 msec (P2), 32.8 +/- 2.8 msec and 34.6 +/- 2.5 msec (N2), respectively. The amplitude of control and post epidural anesthesia of N1-P2, P2-N2 were 4.5 +/- 2.9 microV, 5.9 +/- 6.6 microV (N1-P2), 4.4 +/- 3.2 microV and 5.6 +/- 5.2 microV (P2-N2), respectively. Peak latencies of all components (L1, P2, N2) increased after epidural anesthesia compared with control values. Amplitude of N1-P2 increased significantly following epidural anesthesia compared with control values. The data obtained in this study were contrary to the previous concept that anesthetic agents generally increase the latency of SSEP and decrease their amplitude.     

胸段硬膜外复合静脉全麻与全凭静脉麻醉在开胸手术中的比较

目的 比较胸段硬膜外复合静脉全麻与全凭静脉麻醉对开胸手术患者血流动力学、麻醉药维持剂量、术后苏醒、躁动及疼痛的影响.方法 64例择期行剖胸手术患者,ASA Ⅱ级～Ⅲ级,采用完全随机设计的方法分为2组.A组:胸段硬膜外复合静脉全麻组,患者预先用10 ml 0.25%布比卡因和0.1 mg芬太尼硬膜外给药.术中硬膜外0.25%布比卡因和芬太尼10μg/ml,5 ml/h复合丙泊酚维持.B组:全凭静脉麻醉组,丙泊酚-端芬太尼全凭静脉麻醉.观察并记录不同时间点2组心率(HR)、平均动脉压(MAP)、中心静脉压(CVP)、所需麻醉维持药量、术毕清醒及出现疼痛时间.结果 2组患者各观察点血流动力学变化比较,差异无统计学意义;胸段硬膜外复合静脉全麻组麻醉维持不需要静脉镇痛药瑞芬太尼和肌松药阿曲库铵,只需复合充分的丙泊酚镇静,就能满足手术需求;术后苏醒早;拔管时间(11±4)min,相对于全凭静脉麻醉组(23±16)min明显缩短(P<0.05):躁动例数显著减少;术后出现疼痛时间(7.4±2.6)min相对于全凭静脉麻醉组(0.5士0.3)min明显延长(P<0.01).结论 胸段硬膜外复合静脉全麻用于开胸手术快通道麻醉是一种安全、经济、有效并有利于患者术后恢复的麻醉方法.     

Effects of systemic morphine and epidural bupivacaine on postoperative oxygen consumption during rewarming

The alterations in hemodynamics and oxygen consumption as a consequence of continuous epidural infusions of bupivacaine at room temperature and conventionally administered morphine were studied during recovery from general anesthesia for total hip replacement. Twenty-four patients were randomized to receive either bupivacaine or morphine in the recovery room. The bupivacaine group received from 6 to 12 ml per hour of 0.25% bupivacaine epidurally. Patients in the morphine group received 0.1 mg/kg of morphine intramuscularly no more frequently than every 4 hours. A pulmonary artery flotation catheter was inserted into each patient to determine hemodynamics and oxygen consumption at three instances: before analgesia, when pulmonary artery blood temperature reached 36 degrees C, and when it reached 37 degrees C. During the rewarming there was a decrease in mean arterial blood pressure and the systemic vascular resistance index and an increase in heart rate. The whole body oxygen consumption index increased in the bupivacaine group at the last measuring point but was stable in the morphine group. There was no effect on the arterial-venous oxygen content difference in either group. At 37 degrees C, the cardiac index and oxygen consumption index were significantly higher in the bupivacaine group than in the morphine group. In contrast to regional analgesia, systemic morphine administration can partially antagonize cardiovascular response to postoperative rewarming because it induces a stable oxygen demand.     

Respiratory and hemodynamic effects of thoracic or lumbar epidural alfentanyl after thoracic surgery

OBJECTIVES: The aim of this study was to evaluate the effects on pulmonary function and hemodynamics of three different types of analgesia after thoracotomy. MATERIAL AND METHODS: Forty-five ASA II-IV patients undergoing thoracotomy (for lobectomy or pneumonectomy) were randomized to three groups (n = 15 each) for double-blind study. After a test dose into the epidural space at T5-7 (groups T-A and T-AL) or L2-3 (group L-A) interspace, 10 micrograms/Kg of alfentanil was administered in all groups, followed by epidural infusion of 400 micrograms/h of alfentanil (group T-A and L-A) or 400 micrograms/h of alfentanil with 50 mg/h of lidocaine (group T-AL) during surgery and 24 hours postoperatively. The patients also used a patient-controlled analgesia device to administer intravenous morphine postoperatively. During the study period the following variables were recorded: hemodynamic parameters, lung function, quality of analgesia and respiratory complications. ANOVA was performed and Scheffé and Chi-square tests were applied with 0.05 as the level of statistical significance. RESULTS: No differences were found between groups with respect to patient characteristics or type of surgery. Rescue analgesia requirements were higher in group L-A than in the other groups. PaO2 (6 and 18 hours) and spirometric parameters (12 and 18 hours) were significantly higher in group T-AL than in the other groups (p < or = 0.05). No other statistically significant differences were found. CONCLUSIONS: Respiratory parameters were better after thoracic epidural analgesia with alfentanil and lidocaine than after the other analgesic techniques studied. Group L-A patients had greater need for rescue analgesia than did patients in the other groups.     

Transient acute respiratory failure and thoracic epidural anesthesia

A case is reported of acute respiratory failure occurring during upper abdominal surgery in a patient not previously known to have chronic respiratory failure. Preoperatively, this 68 year old patient presented with mild obesity, slight effort dyspnoea and paralysis of the right hemidiaphragm, a sequela of polytrauma she suffered the year before. Respiratory tests were not considered useful with regard to the results of clinical examination. Moreover, she had already several previous general anaesthetics without any problems. A thoracic epidural anaesthesia was performed with a mixture of 150 mg lidocaine, 37.5 mg bupivacaine with adrenaline and 100 micrograms fentanyl, injected in the T8-T9 epidural space via a catheter. Ten minutes after the starting of surgery, the patient became agitated and complained of difficulty in breathing. Blood gas analysis showed hypercapnia, with respiratory acidosis (Pao2: 28.19 kPa; Paco2: 9.2 kPa; pH 7.273). Clinical examination revealed a bilateral Horner syndrome (T1-T4 sympathetic blockade). The patient was intubated and ventilated after adequate sedation. She was extubated 3 h 30 min after the initial epidural injection. Epidural analgesia was maintained during 72 h, with 0.1% bupivacaine, with no recurrence of respiratory failure.     

Coronary artery spasm under thoracic epidural anesthesia

Three paroxysmal episodes of ST-segment elevation in lead II of ECG were observed during bullectomy and chest closing under epidural anesthesia supplemented with enflurane in compressed air in a patient who had history of variant angina with 50% obstruction of right coronary artery. The first and the third episodes were followed by ventricular tachycardia, complete A-V block and hypotension. These attacks were preceded by decreases in heart rate and blood pressure. It was suspected that coronary artery spasm developed with increased vagal tone under thoracic epidural block. The first and the second attacks were successfully treated with intravenous injection of nitroglycerin and lidocaine. The third attack needed additional treatments which included intravenous administrations of atropine, epinephrine, isoproterenol and phenylephrine and direct heart massage through the thoracic incision. Postoperative serial examinations of ECG showed inverted T in lead V1-V4, and serum enzymes (GOT, GPT, LDH, CPK, CPK-MB) were elevated. However ratio of CPK-MB to total CPK was only 1.5%. The patient was discharged two weeks after the operation with normal ECG and serum enzymes. It is speculated that coronary artery spasm was induced by hypotension and vagal stimulation under epidural anesthesia which blocks cardiac sympathetic nerves.     

High epidural thoracic anesthesia for pericardial surgery

Here are reported three cases involving patients (77, 61 and 58 years-old) with recurrent pericardial effusion who underwent pleuropericardial window using thoracic epidural anesthesia (T1-T2 o T2-T3) while fully awake, without endotracheal intubation. The operative and postoperative courses were uneventful. During the pneumothoracic phase the vital parameters and spontaneous ventilation patterns remained the same compared to the basic ones. Pain control was excellent. On the basis of this early experience the authors conclude that thoracotomy in awake patients to reach the cardiac structures is a reproducible technique.     

冠心病心力衰竭病人胸段硬膜外阻滞后心功能变化

目的：观察冠心病心力衰竭（CHF）病人高位胸段硬膜外阻滞（HTEA）前后脂质过氧化物和左心室舒缩功能的变化,方法：选择48例冠心病心力衰竭病人均分为HTEA组（n=24)及常规治疗组（n=24),观察治疗前后心功能,丙二醛（MDA）,超氧化物歧化酶（SOD）的变化。结果：治疗后CHF病人心脏舒缩功能的改善;HTEA组明显优于常规治疗组（P＜0．05）,MDA含量HTEA组明显低于常规治疗组（P＜0．01）,SOD则明显高于常规治疗组（P＜0．05）,结论：HTEA治疗CHF病人对心脏舒缩功能的改善明显优于常规法,其增强抵抗自由基的能力是可能的机制之一。