Efficacy of leukocyte-depleted terminal blood cardioplegia in congenital heart disease.

OBJECTIVE: Activated leukocytes and their products play a significant role in reperfusion injury and cause microvascular occlusion--the 'no-reflow phenomenon'--which decreases coronary blood flow after the release of the aortic cross-clamp during open-heart surgery. This study was designed to evaluate the efficacy of leukocyte-depleted terminal blood cardioplegia in patients with right ventricular pressure or volume overloaded congenital heart disease undergoing intracardiac repair. SUBJECTS AND METHODS: Fourteen infants and children undergoing intracardiac repair for congenital heart defects were the subjects in this study. Leukocyte-depleted terminal blood cardioplegia was employed in seven patients (Group I). For the control, terminal blood cardioplegia with leukocytes was employed in seven patients (Group II). In order to evaluate the myocardial anaerobic metabolism, the arteriovenous difference in the pyruvate and lactate levels was compared between both groups. Blood samples were taken simultaneously from both the arterial limb of the bypass circuit and the coronary sinus immediately after, and at 5, 10, and at 20 minutes after, the release of the aortic cross-clamp. RESULTS: The coronary arteriovenous difference in the pyruvate and lactate levels demonstrated that the myocardial anaerobic metabolism in Group II was significantly higher than in Group I. The delta excess lactate demonstrated that myocardial hypoxia in Group II persisted significantly longer than in Group I. There was a tendency for the creatine kinase-MB level at 6 hr after surgery to be lower in Group I than in Group II. CONCLUSION: Leukocyte-depleted terminal blood cardioplegia may reduce the myocardial anaerobic metabolism in patients with right ventricular pressure or volume overloaded congenital heart disease undergoing intracardiac repair.     

心内直视手术中去白细胞血灌注液对心肌的保护作用

目的 评价心内直视手术期间使用滤除白细胞的血液灌注液对心肌的保护效果。方法 ３０例择期行心脏瓣膜替换术的患者，ＡＳＡⅡ～Ⅳ级，均采用芬太尼－安氟醚复合麻醉，以４℃高钾晶体液灌注停跳，据第二次灌注液成份不同随机分为３组，每组１０例；晶体 组（ＣＳ）、全血组（ＷＢ）和去白细胞血（ＬＤ）组，于肝素化前，ＣＰＢ开始５ｍｉｎ，主动脉开放前５ｍｉｎ，开放后３０ｍｉｎ、１ｈ、２ｈ、２４ｈ采取外周动脉血测定ＣＫ－ＭＢ、ＩＬ－８、ＴＮＦα浓度，于主动脉阻断前、开放前、开放后１５ｍｉｎ取右心房心肌标本，测定心肌含水量和心肌组织Ｃａ＾２＋含量和心肌组织Ｃａ＾２＋含量，观察心肌组织超微结构改变，对心肌线粒体变化进行半定量评价。结果 开放主动脉后，每组ＣＫ－ＭＢ、ＩＬ－８水平较开放前明显升高，开放后２ｈ升高更明显（Ｐ〈０．０５），但ＬＤ     

Cosmetic benefits of lower midline skin incision for pediatric open heart operation

OBJECTIVE: Since we developed the procedure in 1996, we have now performed 100 pediatric open heart operations using a lower midline skin incision and a minimal sternotomy approach. METHODS AND RESULTS: To elucidate the benefits of this approach, we analyzed these 100 cases retrospectively. There was no death, and no major complication, caused by this approach, and the resulting scarring in each patient is difficult to be seen under a common undershirt. CONCLUSION: This review shows that the technique of a lower midline skin incision and minimal sternotomy approach is a safe reliable and cosmetically advantageous method for a pediatric cardiac operation.     

脱白细胞温血心脏停搏液对心脏瓣膜置换术患者心肌的保护作用

目的研究脱白细胞温血心脏停博液微流量连续灌注对体外循环下瓣膜置换术患者心肌的保护效果。方法拟行心脏瓣膜置换术患者4JD例,随机分为对照组和试验组,每组20例。对照组:采用温血心脏停博液微流量连续顺行灌注;试验组:采用脱白细胞的温血心脏停博液微流量连续顺行灌注。采集术中不同时间点静脉血标本,检测血浆类脂肪酸结合蛋白、丙二醛及右心房心肌内髓过氧化物酶水平。结果试验组主动脉开放30、60min血浆类脂肪酸结合蛋白、丙二醛均较主动脉阻断前升高,但均低于对照组(P<0.05)。试验组心肌内髓过氧化物酶在主动脉开放后与阻断前相比差异无统计学意义(P>0.05),而对照组与阻断前相比增加(P<0.05),两组之间比较,差异有统计学意义。结论脱白细胞温血心脏停博液微流量连续灌注,可有效减轻心肌缺血再灌注损伤。     

Experimental evaluation of secondary blood cardioplegia

Reperfusion damage after ischemia may be evidenced by myocardial cell edema, intracellular calcium accumulation, and limited utilization of oxygen. The need for cardioplegic arrest during initial reperfusion to allow oxygen to be used for reversing ischemic damage rather than for electromechanical activity has been propounded by some researchers. Reports of greater postischemic compliance and performance, low postischemic edema, and greater oxygen uptake at a perfusion pressure of 50 mm Hg or lower have been cited. The present study was conducted on 24 pigs having 2-hr cardioplegic arrest, which of 12 underwent normal reperfusion and 12 experienced secondary cardioplegia followed by normal reperfusion. The results showed that in spite of improved high-energy phosphate preservation, the secondary cardioplegia group had higher myocardial edema, less coronary flow, and poorer contractility and compliance at the end of 1 hr of reperfusion. Because of these findings and contradictory results reported by other groups, caution is urged in the clinical extrapolation of the results of such studies pending further investigations.     

A comparison of ischemic preconditioning versus terminal warm cardioplegia with controlled reperfusion in open heart operation

BACKGROUND: The purpose of this study was to evaluate the effects of three different methods of cardioprotection in patients undergoing valve replacement. METHODS: Ninety patients undergoing elective valve replacement were randomly divided into three groups. In group 1 (n=30), the patients received intermittent cold blood cardioplegia. In group 2 (n=30) they received terminal warm cardioplegia and controlled reperfusion, and in group 3 (n=30), the patients received two cycles of ischemia (2 minutes) and reperfusion (3 minutes) before heart arrest induced by cold blood cardioplegia. The parameters of cardiac function, creatine kinase MB, and clinical outcomes were recorded to assess the effects of experiment. RESULTS: The major preoperative and intraoperative variables are comparable within the three groups. The number of patients requiring the support of inotropic agents was 70% (21/30), 33% (11/30) and 40% (12/30) in group 1, 2 and 3, respectively (p<0.05). The doses of inotropic agent in groups 2 and 3, were significantly lower than in group 1 (1.5+/-0.3 and 1.8+/-0.4 versus 4.5+/-0.8 microg x kg x min(-1), p<0.01) during the first 24 hours after operation. Two deaths (30 day-hospital mortality) occurred, one in group 1 and one in group 2. The cardiac index at 2 hours after bypass discontinuing were 2.2+/-0.04, 3.0+/-0.1 and 2.8+/-0.05 L/m(2) in group 1, 2 and 3, respectively (p<0.01). The left ventricular stroke work index were 24.8+/-1.3, 34.5+/-1.6 and 31.6+/-1.2 g/m x m(2) in group 1, 2, 3, respectively (p<0.01). The release of CK-MB in group 2 and 3 were lower than in group 1 (68+/-7, 81+/-9 versus 116+/-10 IU/L, p<0.01). CONCLUSIONS: Terminal warm cardioplegia with controlled aortic root reperfusion and ischemic preconditioning equally improve cardiac function and reduce the requirement of inotropic agents in patients undergoing valve replacement.     

温血心停跳液持续灌注对心内直视术中犬心肌细胞质膜的保护作用

目的观察温血心停跳液持续灌注对心内直视术中犬心肌细胞质膜的保护作用。方法采用温血心停跳液持续灌注（ＣＷＢＣ）或冷晶体心停跳液间断灌注（ＩＣＣＣ）作心肌保护。以镧（Ｌａ３＋）标记电镜技术观察心肌细胞质膜通透性的改变。结果主动脉阻断前，两组心肌组织中Ｌａ３＋局限在心肌细胞外间隙沉积；再灌注后６０分钟，对照组心肌细胞线粒体内、周边及肌原纤维上有Ｌａ３＋沉积，实验组心肌细胞内无Ｌａ３＋沉积。结论①Ｉ／Ｒ损伤后早期，心肌细胞质膜通透性增高；②ＣＷＢＣ可以减轻心肌损伤，很好地维持心肌细胞质膜的完整性。     

Prevention of reperfusion injury in the neonatal heart with leukocyte-depleted blood

Activated leukocytes release oxygen free radicals and cause microvascular occlusion. This experiment tests the hypothesis that reperfusion with leukocyte-depleted blood reduces injury after extended ischemic preservation. An in vitro model consisting of an isolated, working neonatal piglet heart and an adolescent support pig was used. Hearts were arrested with a cold crystalloid cardioplegic solution, excised, and stored in 4 degrees C saline for 12 hours. Two groups were compared. In group 1 piglets (n = 8), reperfused with whole blood, the maximum stroke work index was 0.91 +/- 0.29 x 10(3) erg/gm (mean +/- standard error of the mean). Group 2 piglets (n = 6), reperfused with blood depleted of leukocytes by a polyester filter, had a maximum stroke work index of 11.6 +/- 1.0 x 10(3) erg/gm. This difference was highly significant (p less than 0.0001). Group 1 exhibited severe injury with myofibrillar necrosis, mitochondrial disruption, nuclear chromatin clumping, and moderate interstitial edema. Group 2 had normal ultrastructure on electron microscopic examination. We conclude that reperfusion with leukocyte-depleted blood prevents reperfusion injury and results in excellent myocardial function after long-term heart preservation.     

Electroplegia: an alternative to blood cardioplegia for arresting the heart during conventional (on-pump) cardiac operation

BACKGROUND: Aortic cross-clamping is contraindicated in patients with severe atherosclerosis of the ascending aorta, and administration of chemical cardioplegia may be cumbersome in these patients. In this study, we demonstrate an alternative method of achieving cardioplegia by electrical stimulation of the vagus nerve. METHODS: In anesthetized canines, the left anterior descending coronary artery was reversibly ligated for 90 minutes, followed by cardiopulmonary bypass (CPB) and randomization to three groups (n = 8 each): (1) BCP group: 1 hour of intermittent hypothermic (4 degrees C) blood cardioplegia infusion; (2) CPB group: 1 hour of CPB alone; (3) EP group (group receiving electroplegia): 1 hour of intermittent vagal stimulation (total of 60 20-second electrical stimuli at 40 Hz, 6 to 10 V) with adjunctive pyridostigmine (0.5 mg/kg), verapamil (50 microg/kg), and propranolol (80 microg/kg) to potentiate hyperpolarization and suppress ectopic escape beats. RESULTS: The EP group achieved consistent intervals of arrest with 3.8 +/- 1.2 escape beats per 20-second stimulation period. After 2 hours of reperfusion off CPB, the left anterior descending coronary artery segmental shortening was reduced from baseline in all groups, but the segmental shortening recovered to a greater extent in the EP group than in either the CPB or BCP group (2.4% +/- 1.4% versus -1.3% +/- 1.3% versus -4.0% +/- 0.8%, p < 0.05). Infarct size (TTC stain, percentage of area at risk) was comparable among groups (EP: 20.9% +/- 4.7%; CPB: 29.6% +/- 3.2%; BCP: 25.1% +/- 5.7%). Postischemic left anterior descending coronary artery endothelial function (percent maximum relaxation to acetylcholine) was depressed in the EP group (68.6% +/- 7.6% versus 102.3% +/- 6.4%, p < 0.05), but was comparable versus nonischemic circumflex function in the BCP group (77.1% +/- 11.9% versus 100.4% +/- 10.0%, p = 0.15) and the CPB group (93.8% +/- 6.6% versus 93.3% +/- 6.6%). CONCLUSIONS: Electroplegia achieves elective intermittent cardiac arrest, avoids hypothermia, chemical cardioplegia, and aortic cross-clamping, with physiological outcomes comparable to blood cardioplegia.     

Lidocaine-magnesium blood cardioplegia was equivalent to potassium blood cardioplegia in left ventricular function of canine heart

This study evaluated the effects of lidocaine-magnesium blood cardioplegia on left ventricular function compared with potassium blood cardioplegia. Crystalloid cardioplegia which contains lidocaine has been reported but blood cardioplegia is rare. Thirteen dogs received 60 min of global ischemia under hypothermic cardioplumonary bypass (30 degrees C). Potassium blood cardioplegia was administered every 20 min in group A (n=6), and lidocaine-magnesium blood cardioplegia in group B (n=7). We compared the ratio of Emax obtained during IVC occlusion at pre- and post-global ischemia (%Emax) and LVSW (%LVSV). Cardiac function was evaluated prior to CPB and 60 min after reperfusion. There was no difference in time required for cardiac arrest between the two groups (group A: 78+/-3 s, group B: 89+/-9 s). Percentage maximal elastance was significantly better in group B (group A: 63+/-3%, group B: 76+/-4%, P<0.05). Percentage tissue water content of the myocardium after CPB was significantly lower in group B (group A: 82.3+/-4%, group B: 75.5+/-2%, P<0.05). Lidocaine-magnesium blood cardioplegia was equivalent to potassium blood cardioplegia in systolic left ventricular function and reduced myocardial edema in canine heart.     

心脏不停跳体外循环心内直视手术时芬太尼用量的探讨

目的 探讨芬太尼在不停跳体外循环心内直视手术麻醉时的用量。方法 选择27例心内直视手术病人,随机分为3组:G1、G2和G3组,每组9例,芬太尼用量为G1组10μg·kg-1、G2组30μg·kg-1、G3组50μg·kg-1。于麻醉前(T0)、气管插管后5 min(T1)、开胸后即刻(T2)、转流前即刻(T3)、转流15 min(T4)、停机后10 min(T5)和关胸后5 min(T6)采集动脉血标本用放免分析法测定血气、电解质、促肾上腺皮质激素(ACTH)、血管紧张素(AⅡ)、皮质醇和血糖水平,监测HR、MAP、CVP、SpO2、PxrCO2、鼻咽温和直肠温。记录术后清醒时间和拔管时间等。结果 三组病人的年龄、体重、转流时间和手术时间比较差异无显著性(P>0.05)。HR、SpO2、PETCO2、鼻咽温、直肠温、血气、电解质在整个手术过程中无明显变化;MAP在转流中最低,各时点MAP与麻醉前相比均降低(P<0.05);三组病人的血糖、ACTH、AⅡ和皮质醇浓度在转流中、停机后和关胸后与麻醉前相比显著升高(P<0.05),麻醉后同一时点的三组数值以G1组最高(p<0.01),而G2与G3比较差异无显著性(p>0.05);术后清醒时间和拔管时间以G1为最短(P<0.05),而G2与G3比较差异无显著性(P>0.05)。结论对不停跳体外循环心内直视手术病人,芬太尼的合适剂量为30μg·kg-1。     

可乐定口服在小儿心脏直视手术麻醉中的应用

目的：调查可乐定在小儿先天性心脏病术前口服中的作用。方法：选择２２例，随机分为可乐定组（ｎ＝１２）和常规组（ｎ＝１０）。采取麻醉前、气管插管后、劈胸骨后和体外循环复温时的动脉血液，测定血浆中皮质醇、胰高血糖素和血管紧张素Ⅱ的含量变化。结果：血浆胰高血糖素与血管紧张素Ⅱ无明显差异（Ｐ＞０．０５）；血浆皮质醇在麻醉前可乐定组与常规组比较，无统计学意义，在气管插管后、劈胸骨后和体外循环复温时可乐定组均明显高于常规组（Ｐ＜０．０５、Ｐ＜０．０１、Ｐ＜０．０１）。结论：可乐定可以取代吗啡作为小儿先天性心脏病的麻醉前用药。     

胸骨下段小切口心脏不停跳心内直视手术

目的探讨胸骨下段小切口心脏不停跳技术在心内直视手术中的应用效果. 方法对202例先天性心脏病或风湿性心瓣膜病患者施行心内直视手术.胸骨下段小切口从剑突至第2肋间正中锯开胸骨,并横断右半侧胸骨,切口长6～12 cm,保持胸骨柄的连续性.心内直视手术在心脏不停跳下完成. 结果所有患者手术均顺利,术后平均胸腔引流量为186.15±65.27 ml.手术死亡3例,死亡原因低心排血量综合征、心室颤动和肾功能衰竭.其余患者均治愈出院,随访1～42个月,无晚期死亡. 结论胸骨下段小切口结合心脏不停跳技术,可安全、有效地应用于大部分心内直视手术,临床效应互补,既有创伤小、出血少、美观等优点,又有心肌保护作用.     

Clinical trial of nicardipine cardioplegia in pediatric cardiac surgery

To clarify the effectiveness of nicardipine, one of the dihydropyridine calcium-channel blockers, for myocardial protection during cold potassium cardioplegic arrest in pediatric cardiac surgery, a clinical trial of nicardipine (0.25 mg/L) added to potassium cardioplegic solution was performed in children undergoing surgical repair of congenital heart diseases. Twenty patients were selected to receive nicardipine cardioplegia and 13 patients received a standard potassium cardioplegia, serving as a control group. Nicardipine cardioplegia provided better cardiac performance in the early postoperative period and reduced release of the MB isozyme of creatine kinase, as determined during a 48-hour postoperative period. These results suggest that nicardipine added to cold potassium cardioplegic solution offers additional protection for the myocardium during ischemia and postischemic reperfusion in pediatric cardiac surgery.     

Propranolol for intractable hemolysis after open heart operation

Postoperative intravascular hemolysis occurring in 2 patients was alleviated by propranolol. One patient underwent mitral valve replacement and had development of intractable hemolysis due to a paravalvular leak. The other patient underwent ventricular septal defect closure and had hemolysis caused by the Dacron patch. Both patients were given oral propranolol, and the degree of hemolysis decreased substantially. Although the exact mechanism of the propranolol effect on mechanical intravascular hemolysis is unclear, propranolol is thought to reduce the shearing stress between erythrocytes and the foreign material by slowing the velocity of the circulation.     

Relationship between increased blood pressure and hematocrit during modified ultrafiltration for pediatric open heart surgery

Objective Modified ultrafiltration increases blood pressure after cardiopulmonary bypass in children. To investigate the cause of this hemodynamic improvement, we assessed the relationship between increased blood pressure and hematocrit. Methods We retrospectively assessed 30 consecutive patients who underwent ventricular septal defect closure, and divided them into two groups: group M (modified ultrafiltration, n = 15) and group C (conventional ultrafiltration, n = 15). We compared the intraoperative transitions of blood pressure and hematocrit, and analyzed the correlations between blood pressure and hematocrit at 15 min after cardiopulmonary bypass (immediately after modified ultrafiltration in group M) and between the percent increases in blood pressure and hematocrit during modified ultrafiltration. Results Although intraoperative central venous pressure and dopamine dosage were similar, in group M, increases in hematocrit (26.4% ± 4.9% to 31.9% ± 5.7%, P < 0.01) and systolic blood pressure (61.1 ± 10.3 to 75.6 ± 11.5 mmHg, P < 0.01) occurred during modified ultrafiltration. Furthermore, diastolic and mean blood pressure at 15 min after cardiopulmonary bypass (after modified ultrafiltration) were higher in group M than in group C. However, systolic, mean, and diastolic blood pressure were not correlated with increased hematocrit after modified ultrafiltration, and there was also no correlation between the percent increases in each blood pressure and hematocrit. Conclusion Modified ultrafiltration increased blood pressure and hematocrit immediately after cardiopulmonary bypass in children. However, no correlations were detected between the increases in blood pressure and hematocrit. These results indicate hemoconcentration is not the major cause of the increased blood pressure during modified ultrafiltration.