Thyroid function during and after cardiopulmonary bypass in children

Background: The aim of the study was to elucidate the changes in thyroid function during and after cardiopulmonary bypass (CPB) in children.
Methods: Triiodothronine (T3), thyroxine (T4), free thyroxine (FT4) and thyroid-stimulating hormone (TSH) were determined preoperatively, at specific times throughout CPB, and serially up to 48 h postoperatively, in 10 children (median age 35, range 23–68 months) undergoing elective surgery for congenital heart disease.
Results: T3 decreased from 2.01±0.08 preoperatively to 0.94±0.10 nmol/1 24 h postoperatively ( P <0.05). T4 levels followed a pattern similar to changes in T3. FT4 increased from 17.4±0.7 preoperatively to 30.0±0.4 pmol/1 after 30 min of CPB ( P <0.05). TSH decreased from 2.44±0.43 preoperatively to 0.93±0.21 24 h postoperatively ( P <0.05).
Conclusion: T3, T4 and TSH are significantly depressed after open heart surgery in children.     

Delayed rises in serum S100B levels and adverse neurological outcome in infants and children undergoing cardiopulmonary bypass

BACKGROUND: The protein S100B is a marker of brain injury. Early after cardiopulmonary bypass (CPB), serum S100B levels are artefactually high. We investigated whether delayed (48 h) rise in S100B levels may have a role in detecting brain injury after CPB. METHODS: Data from 43 children were analysed in this study. Samples were collected at preincision and 30 min, 24 and 48 h postbypass and then analysed by using a commercially available radioimmunoassay (Sangtec100). Charts were reviewed at 3-5 months for evidence of neurological injury. RESULTS: S100B levels were high preoperatively in neonates and universally high immediately postbypass. In 36 children, samples were available for all time points. Compared with preoperative levels, rises occurred at both 24 and 48 h in three patients, only at 24 h in four patients and only at 48 h in three patients. Two patients had evidence of neurological injury. A rise at 48 h was associated with neurological injury (odds ratio 33.9, P < 0.03, 95% CI 1.39-827). There was no association between neurological injury and S100B levels at 24 h. Both the patients with neurological injury had rises at 48 h that were significantly higher than patients with rises at 48 h without injury. CONCLUSIONS: The results of this study suggest that monitoring S100B levels in the late postoperative period may still have a role in detecting neurological injury after cardiac surgery in children. Consistent with previous observations, S100B is high preoperatively in neonates and early postbypass in all patients.     

血浆S100蛋白在体外循环术后脑损伤评价中的意义

目的：探讨血浆S100蛋白在体外循环术中和术后脑损伤评价中的意义。方法：体外循环下心内直视手术病人40例，在体外循环中和结束后不同时间点采血测定血浆S100浓度，并观测病人术后精神神经系统并发症。结果：体外循环可引起病人血浆S100蛋白明显升高，水平最高的3例术后均出现明显的精神神经系统症状，术后24～48h无精神神经并发症者血浆S100蛋白恢复到术前水平。结论：体外循环引起的血浆S100蛋白水平变化对体外循环术后脑损伤的评价具有重要意义。     

体外循环中S-100蛋白和神经元特异性烯醇化酶的变化及其与炎性细胞因子的关系

目的观察体外循环(CPB)手术期间S-100蛋白和神经元特异性烯醇化酶(NSE)的变化,探讨其与炎性细胞因子的关系.方法于CPB前、复温即刻、主动脉开放和CPB后6、24小时采集52例心脏病患者颈内静脉血,检测S-100蛋白和NSE的浓度,并将其与炎性细胞因子白细胞介素-6(IL-6)、白细胞介素-8(IL-8)、肿瘤坏死因子-α(TNF-α)和诱导型一氧化氮合成酶(iNOS)的浓度变化进行相关性分析.结果CPB开始后即有S-100和NSE升高(P<0.05),在术后6小时达到高峰(P＜0.05),术后24小时均恢复至术前水平(P＞0.05),二者变化趋势相同;S-100蛋白和NSE的变化与炎性细胞因子及iNOS浓度的变化有明显的相关性.结论CPB期间可出现S-100和NSE的一过性升高,此与炎症反应中释放的炎性细胞因子及iNOS的过度表达和产生有关,而患者多无明显的脑损害临床表现.     

Basal and nitroglycerin-induced exhaled nitric oxide before and after cardiac surgery with cardiopulmonary bypass

Background. Exhaled nitric oxide (NO) may reflect NO productionand consumption but the pulmonary origin of NO in exhaled gasis not clear. There are also conflicting data on exhaled NOafter cardiopulmonary bypass (CPB). Because intravenous nitrovasodilatorsincrease exhaled NO by conversion to NO in the lung, we measuredbasal and nitroglycerin (GTN)-induced exhaled NO in patientshaving low-risk coronary artery bypass graft (CABG) operationsusing routine CPB. We reasoned that GTN-induced exhaled NO wouldbe a primarily vascular mechanism, which would contrast withthe airway epithelial origin of basal exhaled NO, and that theymight be differentially influenced by CPB. Methods. Breath-to-breath concentrations of gas phase NO weremeasured in 12 CABG patients before and 1, 3 and 6 h afterCPB. After the baseline measurements, three increasing dosesof 1, 2 and 3 µg kg^–1 intravenous GTN weregiven by a central venous catheter and exhaled NO and haemodynamicresponses were recorded. Results. Intravenous administration of 1, 2 and 3 µg kg^–1doses of GTN produced a dose-dependent increase in exhaled NOand a reduction in systemic blood pressure. Baseline exhaledNO remained unchanged. Exhaled NO but not blood pressure responseswere reduced 1 and 3 h after CPB. Conclusions. The capacity of the lungs to increase exhaled NOin response to intravenous GTN is reduced after CPB, suggestingmicrovascular injury and/or atelectasis after routine open-heartsurgery. Br J Anaesth 2003; 90: 608–16     

Hemodynamic effects of dobutamine and dopexamine after cardiopulmonary bypass in pediatric cardiac surgery*

Background: After surgical repair of congenital heart disease, inotropic support is sometimes necessary to wean from cardiopulmonary bypass. In pediatric cardiac surgery, dobutamine and dopamine are often used as inotropic support. Dopexamine is a synthetic catecholamine, which has positive inotropic and vasodilating properties. Because the hemodynamic effects of catecholamines are modified after cardiopulmonary bypass, the aim of this study was to investigate the effects of dobutamine and dopexamine on cardiac index and systemic vascular resistance index after cardiopulmonary bypass in pediatric cardiac surgery. Methods: The study was performed in a prospective, randomized, and double‐blinded cross‐over design. The investigation included 11 children for elective, noncomplex congenital heart surgery. After weaning from cardiopulmonary bypass and a 20‐min period of steady state, children received either 2.5 μg·kg^?1·min^?1 dobutamine or 1 μg·kg^?1·min^?1 dopexamine for 20 min. Cardiac index (transpulmonary thermodilution), mean arterial pressure, central venous pressure, stroke volume, systemic vascular resistance, and central venous oxygen saturation were determined. The primary outcome variable was cardiac index. Results: No difference in cardiac index was observed between the two groups (P = 0.594). Both drugs increased cardiac index, dopexamine from 3.9 ± 0.6 to 4.7 ± 0.8 l·min^?1·m^?2 (P = 0.003) and dobutamine from 4.1 ± 0.7 to 4.8 ± 0.7 l·min^?1·m^?2 (P = 0.004). During treatment with dobutamine, children presented with significantly higher mean arterial pressure (P = 0.003) and systemic vascular resistance index (P = 0.026). Conclusions: This trial demonstrates that low‐dose dobutamine and dopexamine both increase cardiac index during pediatric cardiac surgery but with different hemodynamic effects.     

Clinical significance of serum S-100β protein level after pediatric cardiac surgery

OBJECTIVE: The serum S-100 beta protein level is a specific marker of damage to the central nerve system (CNS). We studied its significance in pediatric cardiac surgery as a possible marker of CNS damage. METHODS: Subjects were 18 consecutive pediatric patients aged 12 days to 13 years (mean: 2.8 years) undergoing open-heart surgery. We measured the serum S-100 beta protein level using ELISA (SRL Co. Ltd., Tokyo) immediately after inducing anesthesia and immediately, 12 hours, and 24 hours after weaning from cardiopulmonary bypass (CPB). RESULTS: None had postoperative neurological symptoms. The prebypass serum S-100 beta protein level showed a significant logarithmic correlation with patient age. All patients showed increased S-100 beta protein immediately after weaning from CPB, and multiple regression analysis showed that bypass time and cyanosis were significant factors in such as increase. Cyanosis was the only factor in increased S-100 beta protein levels 12 and 24 hours after weaning from CPB. The peak S-100 beta protein level showed a significant exponential correlation with bypass time. CONCLUSION: Serum S-100 beta protein elevated immediately after weaning from CPB correlated with bypass time but not with neurological symptoms. Physiological changes other than substantial brain damage caused by CPB may increase the serum S-100 beta protein level. Prebypass data on neonates and infants showed serum S-100 beta protein increased without brain damage supporting this hypothesis.     

高渗盐液对心肺转流猪血浆S100蛋白的影响

目的 观察7.5%高渗盐液对心肺转流(CPB)猪血浆S100蛋白含量的影响,探讨其用于CPB术后脑保护的可能性.方法 24头本地6～8周龄健康白猪,随机均分为高渗盐液治疗组(H组)和对照组(C组).H组在CPB前10 min输入7.5%氯化钠4 ml/kg,C组则输入等容积0.9%氯化钠.两组动物均行中度低温CPB 90 min.分别于输液后CPB开始时(T0)、CPB 45 min(T1)、CPB结束时(T2)、CPB结束后1 h(T3)、5 h(T4)各时点采集动脉血,测定血浆S100蛋白含量和K 、Na 、CI-浓度.结果 与T0时比较,两组动物血浆S100蛋白含量在T1～T4时都显著升高(P<0.01);T1～T4时H组血浆S100蛋白含量明显低于C组(P<0.05或P<0.01);与T0时比较,H组动物血浆K 浓度在T2、T4时高于T0时(P<0.01),在T1、T3时低于C组(P<0.05或P<0.01),H组Na 、CI-浓度在T1～T4时都高于T0时和C组(P<0.01),但在正常范围内.结论 小剂量高渗盐液可降低CPB猪血浆S100蛋白含量,提示可能对CPB术后早期脑功能障碍有一定的保护作用.     

The degree of atherosclerosis in the descending aorta does not predict poor in-hospital outcome after surgery requiring cardiopulmonary bypass

OBJECTIVE: This study examined if the degree of atherosclerosis in the descending aorta is an independent predictor of poor in-hospital outcome for patients presenting for surgery involving cardiopulmonary bypass. DESIGN: The degree of atherosclerosis of the descending aorta was retrospectively reviewed in patients presenting for surgical procedures involving cardiopulmonary bypass from January 1, 2000, to December 31, 2003. Preoperative risk factors and in-hospital postoperative outcome parameters were obtained. SETTING: University teaching hospital. PARTICIPANTS: There were 310 consecutive patients enrolled in the study. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Two hundred forty-seven patients had coronary artery bypass grafting with or without valvular surgery, and 63 patients had isolated valvular surgery. The degree of atherosclerosis was rated as normal in 86 (28%), mild in 106 (34%), moderate in 69 (22%), and severe in 49 (16%) patients. Adjusting only for the degree of atherosclerosis, the total intensive care unit (ICU) time and the number of deaths were significantly higher in those patients with severe disease. Multivariable models adjusting for patients' risk factors showed a significant influence of atherosclerosis on total ICU time but not on other outcomes. The strongest predictor of poor outcome was a history of previous stroke (cerebral vascular accident). Other significant factors predicting poor outcome included previous coronary artery bypass surgery, a history of congestive heart failure, a history of dialysis, advanced age, and female sex. CONCLUSIONS: The degree of atherosclerosis in the descending aorta is not an independent predictor of poor in-hospital outcome after surgery involving cardiopulmonary bypass.     

Release of S100B during coronary artery bypass grafting is reduced by off-pump surgery

Background. S100B, a plasma marker of brain injury, was compared after coronary artery bypass grafting with and without cardiopulmonary bypass (CPB).

Methods. Fourteen patients with off-pump operations and 18 patients with CPB were compared. Seven patients in the off-pump group underwent a minithoracotomy and received only an arterial graft, whereas 7 patients underwent sternotomy and received both an arterial and one or two vein grafts. S100B was measured in arterial plasma using an immunoassay with enhanced sensitivity.

Results. S100B before the operation was 0.03 μg/L. At wound closure, S100B in patients of the off-pump and CPB groups reached a maximum level of 0.22 ± 0.07 and 2.4 ± 1.5 μg/L, respectively (p < 0.001). No strokes occurred. Patients without CPB receiving arterial and vein grafts released slightly more S100B (p < 0.05) than patients with only arterial grafting. In patients undergoing CPB, S100B increased slightly before aortic cannulation (p < 0.001), to the same level as the maximum reached for the non-CPB group.

Conclusions. Coronary artery bypass grafting with CPB caused a 10-fold greater increase in S100B than off-pump grafting. S100B release after off-pump sternotomy with vein grafting was slightly greater than in arterial grafting through a minithoracotomy.     

The management of insulin dependent diabetes during cardiopulmonary bypass and general surgery

Two groups of insulin dependent diabetic subjects have been studied: six undergoing general surgical procedures and six undergoing hypothermic cardiopulmonary bypass surgery for coronary artery vein grafting. Intravenous glucose insulin mixtures were infused from the onset of surgery in both groups of patients, supplying 0.4 units of insulin per gram of glucose per hour, and 0.6 units of insulin per gram of glucose per hour in general and cardiac surgical patients respectively. Postoperatively diabetes was controlled carefully with an insulin syringe pump regulated by venous blood glucose monitoring. In cardiac surgical patients far more insulin was required to control diabetes postoperatively than in the general surgery patients (at 1 hour 1.6 units, SEM 0.4 compared to 0.7 SEM 0.1, p less than 0.05; and at 4 hours 2.0 units SEM 0.3 compared to 0.8 units SEM 0.1, p less than 0.02). Five non-diabetic subjects who underwent surgery for coronary artery venous bypass grafting were also studied. They developed significant postoperative hyperglycaemia (5.0, SEM 0.2, mmol/litre pre-operatively, compared with 8.8, SEM 0.7, mmol/litre p less than 0.03 at 1 hour and 10.2, SEM 1.7, mmol/litre, p less than 0.02 at 4 hours after bypass terminated).     

Risks of acute renal failure after cardiopulmonary bypass surgery in children: a retrospective 10-year case-control study

To our knowledge there are no case-control studies that haveexamined the main risk factors for acute renal failure (ARF)following cardiopulmonary bypass surgery in children. We thereforeevaluated the potential risk factors in a large retrospectivecase-control study. Sixty-one of 2262 children (2.7%) developedpostcardiopulmonary bypass surgery ARF requiring peritonealdialysis (PD) from 1982 to 1991. Fifty-eight of 61 cases (medianage 8.5 months) were selected by systematic sampling and matchedwith 176 controls who did not develop ARF. The four matchingvariables were age, cardiopulmonary bypass and circulatory arrestduration, and year of operation. Mortality rate was 79% in cases (controls: 18%). Forty-threeof 48 of the deceased cases did not recover renal function;no renal cause of death was found; 13 of 61 cases survived andrecovered renal function. Multiple regression analysis showedthe following significant risk factors for postcardiopulmonarybypass surgery ARF: central venous hypertension >12 h (oddsratio (OR) 9.6); systolic arterial hypotension >12 h (OR8.9); dopamine dosage >15 µg/kg/min (OR 3.0); adrenaline(OR 5.9) and isoproterenol (OR 13.5) use. High preoperativeserum creatinine, cyanosis, and vasodilator use were not significantrisk factors. We conclude that: (1) haemodynamic alterations were the maincause of postcardiopulmonary bypass surgery ARF; (2) ARF wasassociated with but was not the cause of the high mortalityrate; (3) the risk of ARF increased almost 10-fold after 12h of central venous hypertension and/or of systolic arterialhypotension; (4) effective dosages of inotropes might have beena risk factor for ARF; (5) a slight precardiopulmonary bypasssurgery reduction of renal function alone did not representan increased risk for ARF.     

Effects of dexamethasone on clinical course,C-reactive protein,S100B protein and von Willebrand factor antigen after paediatric cardiac surgery

Background. Anti-inflammatory treatment with glucocorticoidsduring cardiopulmonary bypass can reduce inflammatory mediatorrelease, but the effects of glucocorticoid on outcome are controversial. Methods. We studied the effects of dexamethasone on clinicalcourse, C-reactive protein, von Willebrand factor antigen (vWf:Ag)and S100B in a randomized masked study of children after opencardiac surgery. Twenty children weighing >10 kg receiveddexamethasone (1 mg kg^–1) and 20 controls receivedsaline after induction of anaesthesia. We measured vWf:Ag asa marker of endothelial activation, S100B as a marker of cerebralprotein release and C-reactive protein as a marker of inflammatoryactivity. Oxygenation, body temperature, fluid balance, leucocyteand platelet counts, days in the intensive care unit (ICU) anddays on mechanical ventilation were noted. Results. Dexamethasone decreased C-reactive protein concentrationon the first postoperative day (P<0.05), but did not affectthe release of vWf:Ag or S100B. There was no significant differencein oxygenation, body temperature, fluid balance, leucocyte andplatelet counts, days in the ICU or days on mechanical ventilationbetween the placebo and dexamethasone-treated groups. Conclusion. Administration of dexamethasone before cardiopulmonarybypass for paediatric cardiac surgery decreased the inflammatoryresponse, but did not affect the immediate features after surgeryor changes in vWf:Ag or S100B. Br J Anaesth 2003; 90: 728–32     

心肺转流心脏手术术后谵妄的预防

术后谵妄是手术后常见的神经系统并发症,表现为急性发作的注意力不集中、思维混乱和意识水平的改变等.心肺转流心脏手术患者的术后谵妄发生率明显高于其他类型手术,严重影响患者术后恢复和生存质量.尽管不能完全避免术后谵妄的发生,但有效的预防措施可以明显降低心肺转流心脏手术患者术后谵妄的发生率.本文章回顾近年来国内外术后谵妄的相关...     

Two unusual complications associated with cardiopulmonary bypass for pediatric cardiac surgery detected by transesophageal echocardiography after decannulation

We describe two rare cases of complications associated with cannulation for cardiopulmonary bypass during pediatric cardiac surgery detected by transesophageal echocardiography (TEE). The first patient (a 20-month-old boy, 11 kg) was scheduled for complete repair of an atrial septal defect and partial anomalous pulmonary venous connection. After decannulation of the superior vena cava, a mosaic jet was observed by means of TEE. The second patient (an 11-month-old boy, 6.4 kg), with a double outlet right ventricle, was scheduled for a hemi-Fontan procedure. After decannulation of the ascending aorta, high blood flow velocity of 4 m·s⁻¹ was detected by TEE. Intraoperative TEE was useful for early detection of complications associated with cardiopulmonary bypass cannulation during pediatric cardiac surgery.