Changes in whole blood lactate levels during cardiopulmonary bypass for surgery for congenital cardiac disease: an early indicator of morbidity and mortality

OBJECTIVE: Our objective was to evaluate the change in lactate level during cardiopulmonary bypass and the possible predictive value in identifying patients at high risk of morbidity and mortality after surgery for congenital cardiac disease. METHODS: We prospectively studied lactate levels in 174 nonconsecutive patients undergoing cardiopulmonary bypass during operations for congenital cardiac disease. Arterial blood samples were taken before cardiopulmonary bypass, during cardiopulmonary bypass (cooling and rewarming), after cardiopulmonary bypass, and during admission to the cardiac intensive care unit. Complicated outcomes were defined as open sternum as a response to cardiopulmonary instability, renal failure, cardiac arrest and resuscitation, extracorporeal membrane oxygenation, and death. RESULTS: The largest increment in lactate level occurred during cardiopulmonary bypass. Lactate levels decreased between the postbypass period and on admission to the intensive care unit. Patients who had circulatory arrest exhibited higher lactate levels at all time points. Nonsurvivors had higher lactate levels at all time points. A change in lactate level of more than 3 mmol/L during cardiopulmonary bypass had the optimal sensitivity (82%) and specificity (80%) for mortality, although the positive predictive value was low. CONCLUSIONS: Hyperlactatemia occurs during cardiopulmonary bypass in patients undergoing operations for congenital cardiac disease and may be an early indicator for postoperative morbidity and mortality.     

Thiopentone levels during cardiopulmonary bypass

Plasma total and unbound concentrations of thiopentone were investigated during exponentially decreasing infusions in seven patients undergoing cardiopulmonary bypass. Total plasma thiopentone concentrations reached a plateau (10.2, SD 2.1 micrograms/ml) soon after the initial bolus dose and commencement of the infusion. Concentrations were maintained until the onset of cardiopulmonary bypass, whereupon total plasma thiopentone concentration fell abruptly to 50.0 (SD 5.8) percent of the prebypass level. The unbound fraction of thiopentone increased from 16.6 (SD 1.9) percent before bypass to a maximum of 29.3 (SD 5.6) percent during bypass (p less than 0.01), decreased to 22.9 (SD 3.3) percent at the end of bypass (p less than 0.01), but was still elevated 5-7 hours later (20.5, SD 2.5 percent). The result of the changes in binding was a smaller decline in unbound thiopentone concentration at the onset of bypass to 76.4 (SD 15.7) percent of the prebypass level. Also, unbound levels returned to the prebypass level by the end of bypass, whereas total levels remained low.     

小儿右胸切口体外循环心内直视手术体会

目的　总结经右胸切口行小儿体外循环心内直视手术的体会。方法　 1999年 4月至 2 0 0 1年 8月 ,10 6例先天性心脏病患儿经右胸切口行心内直视根治术 ,年龄 ( 4 .3± 2 .8)岁 ( 4个月～ 14岁 ) ,体重 ( 15 .4± 6.4)kg( 6～ 3 8kg)。病种 :室间隔缺损 68例 ,2例合并二尖瓣返流 ,肺动脉高压 7例。房间隔缺损 3 7例 ,TOF1例。平均总转流时间为 ( 5 3 .9± 2 1)min ,心脏停跳时间 ( 19.2± 15 )min。平均用血量 ( 4 0 0± 5 0 )ml。术后平均呼吸机辅助时间 ( 7.11± 13 )h ,胸引流量 ( 80 .5±5 3 )ml。结果　全组治愈。术后右上或中叶肺不张 9例 ,胸腔少量积液 3例。随访时间 1个月至 2年 ,患儿情况良好。结论　本方法的优点是 :( 1)操作较简便 ,容易掌握 ,尤适用于 2～ 5岁 ,单纯房、室间隔缺损的修补 ;( 2 )手术创伤小 ,术后康复快 ;( 3 )切口美观 ,瘢痕小 ;( 4 )胸引量明显少于正中切口 ,减少术后用血     

Histamine release during adult cardiopulmonary bypass

Histamine, an inflammatory mediator in its own right, may also be a marker for a more widespread systemic inflammatory process. In this study we have examined variations in plasma histamine concentrations produced during the course of cardiac surgery involving cardiopulmonary bypass, the relationship between these variations and intra-operative events. By assays of serum tryptase and CD-63 expression we have also attempted to identify the source of histamine. Histamine concentrations that were significantly raised from baseline level were demonstrated. These were elevated from the time of aortic cross-clamping and continued to be raised for 24 h postoperatively (p < 0.00625). This was associated with an increase in CD-63 expression (p < 0.025) (but not an increase in tryptase concentration) following aortic cross-clamping and protamine administration, suggesting that basophils are the source of histamine. 41% of patients had arrhythmias in the post bypass period. The rise in histamine levels was not related to the incidence of cardiac arrhythmias.     

Anticoagulation with bivalirudin during cardiopulmonary bypass in cardiac surgery

Heparin is the standard agent used for systemic anticoagulation during cardiopulmonary bypass in cardiac operations. Alternatives are needed when patients with heparin-induced thrombocytopenia type II are encountered. We present a patient with a clinical picture of heparin-induced thrombocytopenia type II who was effectively anticoagulated with bivalirudin, a direct thrombin inhibitor, during cardiopulmonary bypass for a cardiac operation.     

Changes of lactate levels during cardiopulmonary bypass in patients undergoing cardiac transplantation: possible early marker of morbidity and mortality

Objectives

High levels of lactate are associated with tissue hypoperfusion during cardiac surgery resulting in postoperative morbidity and mortality among patients undergoing cardiopulmonary bypass (CBP). Our goal was to evaluate the change in lactate levels during CBP for their possible predictive value for complications after heart transplant surgery.

Materials and Methods

From January to December 2010 we studied lactate levels in 16 heart transplant patients. Arterial blood samples were collected before, during, and after cardiopulmonary bypass on admission to the intensive care unit (ICU). Lactate levels were measured using the cobas B221 (Roche Diagnostic). The neurological, lung, and kidney complications were associated with mortality within 30 days.

Results

One patient displayed lactate levels > 2 mmol/L before bypass while 4 (25%) showed levels > 4 mmol/L during CPB. Lactate values higher than or equal to 4 mmol/L on ICU admission occurred in nine patients (56%). Postoperative mortality was higher among the group with levels above below 4 mmol/L on ICU admission (18.7% vs 6.2%). Neurological complications were observed in 22% of patients with elevated levels as opposed to none of the patients with levels below 4 mmol/L. Pulmonary complications were noted in 22% of patients with high lactate values versus 0% among the other group.

Conclusion

Hyperlactemia above certain levels occurring during CPB serve as a biomarker to identify early postoperative morbidity and mortality.     

Outcome of drowned hypothermic children with cardiac arrest treated with cardiopulmonary bypass

Background: There is a lack of data on the outcome of cardiopulmonary bypass (CPB) rewarming of hypothermic children with cardiac arrest following drowning. Aim of the study: To retrospectively analyze single‐center outcome of drowning victims treated with CPB. Materials and methods: This retrospective study included all hypothermic drowning victims admitted to the Hospital for Children and Adolescents with attempted resuscitation on CPB between 1994 and 2008 inclusive. Median sternotomy and cannulation of the ascending aorta and the right atrium for CPB were performed on all victims. Results: Nine hypothermic drowning victims, comprising five boys and four girls, with a median age of 3.8 years (range, 1.5–10 years). The median submersion time was 38 min (range, 5–75 min) and the median water temperature was 6.5 °C (range, 0.2–16.5 °C). The median core temperature was 21.9 °C (range 17.7–32.8 °C) at arrival to the hospital. All nine children were able to be weaned from CPB. Only one child, with mild to moderate neurological deficit, became a long‐term survivor. She was slowly rewarmed up to 33 °C with CPB and kept in mild hypothermia for 48 h. Conclusions: Large numbers of submerged children can be primarily resuscitated with CPB. Unfortunately, many of them will decease from severe hypoxic brain injury. Slow rewarming with CPB may improve the likelihood of a better neurological outcome.     

体外循环下心脏手术肺保护策略

背景 肺损伤是心脏手术体外循环(cardiopulmonary bypass,CPB)的主要并发症之一,肺保护一直是临床、实验研究热点.目的 为CPB下心脏手术肺保护提供参考.内容 就近年来心脏手术CPB期间通气策略和麻醉药物、CPB设备和技术、肺动脉灌注技术、药物干预对肺保护作用的进展进行综述.趋向 CPB下心脏手术...     

Rapid disappearance of protamine in adults undergoing cardiac operation with cardiopulmonary bypass

BACKGROUND: Despite long use of protamine in cardiac operations, neither protamine concentrations nor pharmacokinetics have been reported in patients. METHODS: Twenty-eight patients (age, 26 to 80 years) undergoing various cardiac surgical procedures gave their consent to receive 250 mg of protamine sulfate administered intravenously by an infusion pump during 5 minutes. Protamine was administered at the usual intraoperative time after separation from cardiopulmonary bypass for reversal of heparin. Timed arterial blood samples were obtained after protamine infusion. Blood plasma was subjected to solid-phase extraction and high-performance liquid chromatography. Total (free + heparin-bound) protamine concentration versus time data were subjected to pharmacokinetic modeling. RESULTS: Twenty-six patients completed the study. Total plasma protamine concentrations declined rapidly. Model-independent pharmacokinetic analysis revealed median (range) values as follows: volume of distribution, 5.4 L (0.82 to 34 L); clearance, 1.4 L/min (0.61 to 3.8 L/min); and half-life, 4.5 min (1.9 to 18 min). Schwarz-Bayesian criterion identified a two-compartment exponential model with adjustment for weight in the central compartment volume of distribution as performing better than other compartmental or Michaelis-Menten models. CONCLUSIONS: Protamine has a very short (approximately 5 minutes) half-life after a single 250-mg dose in adult patients. This short half-life could underlie recurrent anticoagulation after initial apparent reversal of heparin.     

Urethral blood circulation during cardiopulmonary bypass

The haemodynamic changes induced by extracorporeal circulation (ECC) are thought to be important in the induction of urethral strictures in open heart surgery when indwelling latex catheters are used. In the present study, 6 piglets were cannulated and connected to extracorporeal perfusion apparatus. Pump flows correlated with human ECC values with non-haemic prime were used. The mucosal and submucosal blood circulation in the urethra reduced by 66% during ECC (P less than 0.05). The brain and hepatic arterial flows increased. A significant reduction was seen in renal blood circulation. The changes in the urethral blood circulation during ECC correlated with previous findings. The reduced wash out levels of chemicals leaching from the indwelling latex catheters as a result of reduced local blood circulation are the main trigger for the induction of urethral strictures during ECC and in other shock-like circulatory disturbances in the human body.     

Coagulation tests during cardiopulmonary bypass correlate with blood loss in children undergoing cardiac surgery.

OBJECTIVES: To examine whether coagulation tests, sampled before and during cardiopulmonary bypass (CPB), are related to blood loss and blood product transfusion requirements, and to determine what test value(s) provide the best sensitivity and specificity for prediction of excessive hemorrhage. DESIGN: Prospective. SETTING: University-affiliated, pediatric medical center. PARTICIPANTS: Four hundred ninety-four children. INTERVENTIONS: Coagulation tests. MEASUREMENTS AND MAIN RESULTS: Demographic, coagulation test, blood loss, and transfusion data were noted in consecutive children undergoing cardiac surgery. Laboratory tests included hematocrit (Hct), prothrombin time, partial thromboplastin time (PTT), platelet count, fibrinogen concentration, and thromboelastography. Stepwise linear regression analysis indicated that platelet count during CPB was the variable most significantly associated with intraoperative blood loss (in milliliters per kilogram) and 12-hour chest tube output (in milliliters per kilogram). Other independent variables associated with blood loss were thromboelastography maximum amplitude (MA) during CPB, preoperative PTT, preoperative Hct, and preoperative thromboelastography angle and shear modulus values. Thromboelastography MA during CPB was the only variable associated with total products transfused (in milliliters per kilogram). Of all tests studied, platelet count during CPB (< or = 108,000/microL) provided the maximum sensitivity (83%) and specificity (58%) for prediction of excessive blood loss (receiver operating characteristic analysis). Blood loss was inversely related to patient age; neonates received the most donor units (median, 8 units; range, 6 to 10 units). CONCLUSIONS: During cardiac surgery, coagulation tests (including thromboelastography) drawn pre-CPB and during CPB are useful to identify children at risk for excessive bleeding. Platelet count during CPB was the variable most significantly associated with blood loss.     

患儿心脏手术心肺转流期间血液保护策略的研究进展

患儿心脏手术围术期失血与输血量增加有关,异体输血可导致心脏手术患儿不良事件发生率增高、预后不佳。围术期血液保护对于减少输血不良反应、缓解血源紧张具有重要的临床意义。心肺转流在围术期血液保护实践管理中占有重要地位。本文就心肺转流(CPB)期间血液保护的灌注策略以及血制品输注策略的最新进展进行综述,为CPB医师在患儿心脏手术CPB期间输血提供参考。     

Serum cytokine levels response to cardiac surgery with cardiopulmonary bypass]

The response of tumor necrosis factor alpha (TNF alpha), interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-10 (IL-10), interleukin-1 receptor antagonist (IL-1ra), macrophage colony stimulating factor (MCSF), white blood cell (WBC), platelet (Plt), lactic acid (LAC) to cardiopulmnary bypass (CPB) were studied until 48 hours after aortic declamping in 11 patients who underwent elective CABG (n = 4), mitral valve plasty or replacement with modified maze procedure (n = 5), and both procedures (n = 2). The highest levels of the cytokines IL-6, IL-8, IL-10, and IL-1ra were observed after the removal of the cross clamp. These cytokines just after the aortic declamping are likely to be occurred not only by an interaction of the blood components with the artificial surfaces, but also by ischemia-reperfusion injury upon discontinuation of the aortic clamping. MCSF increased gradually in the late post-CPB phase and reached a peak at 48 hr after aortic declamping. MCSF may play an important role in regulating hematopoiesis on the postoperative days 1 and 2 in patients. In conclusion, the therapy based on the kinetics of these cytokines would be useful for patients undergoing CPB.