Undergoing cardiopulmonary bypass using enoxaparin only during a cardiac transplantation procedure

The use of enoxaparin as a replacement drug to standard heparin, for anticoagulation during extracorporeal circulation, in patients with heparin-induced thrombocytopenia, is still very limited. Enoxaparin significantly reduces thrombin formation and activity during cardiopulmonary bypass. The prolonged circulating rate, slow elimination rate and non-total reversion of enoxaparin by protamine can induce important postoperative bleeding. We are describing the first case of cardiac transplantation where enoxaparin was used as a replacement drug to standard heparin.     

Pharmacokinetics of ketamine during hypothermic cardiopulmonary bypass in cardiac patients

Cardiopulmonary bypass (CPB) makes prediction of any drug concentration diffcult because both hypothermia and hemodilution can alter the pharmacokinetics of the drug. Eleven patients undergoing cardiac surgery under CPB were anesthetized with continuous infusion of ketamine combined with intermittent administration of droperidol and fentanyl. The infusion rate of ketamine was 2 mg·kg⁻¹·hr⁻¹ following a bolus administration of 1.5 mg·kg⁻¹ for the induction of anesthesia. Blood concentrations of ketamine and its main metabolite, norketamine, were measured at 0, 30, and 60 min after the start of and the end of CPB, and 0, 1, 2, and 24 h after the cessation of ketamine infusion. Hypothermia increased blood ketamine levels during CPB, but the norketamine levels did not change. Although acute hemodilution would decrease blood ketamine levels, their levels were already significantly increased at 30 min after CPB. Hypothermic factors have a more kinetically important role during CPB than hemodilution. Increases in blood norketamine levels following rewarming indicate that hypothermia could impair ketamine metabolism in the liver. Further increase in the plasma concentration of ketamine until 30 min after the end of CPB might be due to blood transfusion containing ketamine from the CPB reservoir.     

Profound hypoxemia during treatment of low cardiac output after cardiopulmonary bypass

PURPOSE: To illustrate the multiple causes of hypoxemia to be considered following cardiopulmonary bypass and how therapy given to improve oxygen delivery may have contributed to a decrease in arterial oxygen saturation to life-threatening levels. CLINICAL FEATURES: A 61 yr old man with severe mitral regurgitation and chronic obstructive lung disease underwent surgery for mitral valve repair. A pulmonary artery catheter with the capacity to measure cardiac output and mixed venous oxygen saturation (SvO2) continuously was used. Two unsuccessful attempts were made to repair the valve which was finally replaced, requiring cardiopulmonary bypass of 317 min. Dobutamine 5 micrograms.kg-1.min-1 and sodium nitroprusside 1 microgram.kg-1.min-1 were used to increase cardiac output. Soon after, the SvO2 decreased progressively from 55 to 39%. The patient became cyanotic with a PaO2 of 39 mmHg. Sodium nitroprusside was stopped and amrinone 100 mg bolus followed by 10 micrograms.kg-1.min-1 was given in addition to adding PEEP to the ventilation. With these measures PaO2 could be maintained of safe levels but PEEP and high inspired oxygen concentrations were needed postoperatively until the trachea could be extubated on the third postoperative day. CONCLUSION: The profound hypoxemia in this case was likely due to a combination of intra- and extrapulmonary shunt, both augmented by sodium nitroprusside. The desaturation of mixed venous blood amplified the effect of these shunts in decreasing arterial oxygen saturation. The interaction of these factors are analyzed in this report.     

Extracorporeal membrane oxygenation versus cardiopulmonary bypass during lung transplantation: a meta-analysis

Background

We reviewed the available literature on patients undergoing lung transplantation supported by cardiopulmonary bypass (CPB) or extracorporeal membrane oxygenation (ECMO).

Methods

A systematic literature search was performed in three databases, in accordance with the PRISMA guidelines. Meta-analyses were used to compare the outcomes of ECMO and CPB procedures.

Results

Seven observational studies met the inclusion criteria incorporating 785 patients. ECMO support showed lower rate of primary graft dysfunction, bleeding, renal failure requiring dialysis, tracheostomy, intraoperative transfusions, intubation time, and hospital stay. Total support time was greater for the ECMO-supported group. No difference was reported between operative and ischemic time.

Conclusions

The present study indicates that the intraoperative use of ECMO is associated with increased efficacy and safety, regarding short-term outcomes, compared to CPB. Well-designed, randomized studies, comparing ECMO to CPB, are necessary to assess their clinical outcomes further.

     

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.     

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...     

Use of leukocyte-depleting filters during cardiac surgery with cardiopulmonary bypass: a review

Numerous researchers and clinicians have shown that cardiopulmonary bypass (CPB) plays a large role in the initiation of the systemic inflammatory response during cardiac surgery. The activation of leukocytes during this process has been implicated as one of the major contributors to multi-organ dysfunction experienced by some patients after cardiac surgery. Thus, in an attempt to attenuate the systemic inflammatory response and to reduce the amount of activated leukocytes from the systemic circulation during CPB, leukocyte-depleting filters were developed in the early 1990s. Since the clinical introduction of these filters into the CPB circuit, several articles have been published evaluating the effectiveness of leukocyte filtration; however, the results have been conflicting. This article will review some of the most recent literature, approximately 40 papers published within the past 10 years, regarding the use of leukocyte-depleting filters during CPB and its effectiveness in preserving organ function. In addition, the effect of different filtration strategies and the effectiveness of the filter to attenuate the systemic inflammatory response in combination with other mechanical and pharmaceutical strategies will be reviewed.     

Improved outcomes during cardiac surgery: a multifactorial enhancement of cardiopulmonary bypass techniques

Patients presenting for cardiac surgery with cardiopulmonary bypass (CPB) are more likely to have pre-existing comorbidities, which has resulted in a steady increase in the risk associated with CPB. The resulting challenge has mandated the optimization of perfusion care. The purpose of this study was to retrospectively evaluate the impact of a number of simultaneous, evidence based perfusion care changes on patient outcome. After Institutional Review Board approval, two groups of patients were compared. The control group (n = 317) included all patients undergoing CPB in a 12-month period preceding a multifaceted change in perfusion techniques. The treatment group (n = 259) included all patients undergoing CPB in the 12-month period after the changes, which included the incorporation of updated continuous blood gas monitoring, biocompatible circuitry, updated centrifugal blood propulsion, continuous autotransfusion technology, new generation myocardial protection instrumentation, plasmapheresis, topical platelet gel application, excluding hetastarch while increasing the use of albumin, viscoelastographic coagulation monitoring, and implementing a quantitative quality improvement program. After univariate analysis, propensity scoring and multiple conditional logistical regression were used to control for demographic, preoperative, operative, and postoperative parameters. Results of the primary endpoints revealed a lower mortality rate in the treatment group (4% vs. 9% [95% confidence interval 1.33, 7.72], p = 0.009), lower transfusion rate (51% vs. 59% [1.00, 2.11], p = 0.048), and lower complication rate (55% vs. 65% [1.06,2.19], p = 0.025) despite having similar predicted mortality (11 [2,22] vs. 11[3,22], p = NS) and other preoperative and operative parameters. The lower mortality rate was concurrent with a trend towards a lower incidence of complications, consistent with the differences in primary outcomes. In conclusion, the patients treated after the implementation of a multifactorial improvement plan using evidence based changes in CPB care had decreased complication and mortality rates.     

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.     

Use of cardiopulmonary bypass for lung transplantation: a 10-year experience

OBJECTIVE: The use of cardiopulmonary bypass (CPB) for lung transplantation (LTx) has been reported previously. This study reports the authors' experience of planned and unplanned use of cardiopulmonary bypass for LTx. DESIGN: Case series. SETTING: A university teaching hospital. PARTICIPANTS: Patients undergoing LTx. INTERVENTIONS: A retrospective analysis of the charts of all patients having undergone LTx over the last 10 years. MEASUREMENTS AND MAIN RESULTS: Among 140 LTx, 23 (16%) were performed with the use of CPB. CPB was planned in 11 cases and unplanned in the 12 other cases. The use of CPB is associated with a longer period of postoperative mechanical ventilation, more pulmonary edema, more blood transfusion requirement, and an increase in postoperative mortality at 48 hours and 1 month. Surgical difficulties related to the dissection of the native left lung and acute right ventricular failure are the main reasons for unscheduled use of CPB. CONCLUSION: Scheduled and unscheduled CPB for LTx are associated with an increased mortality at 1 month and 1 year.     

Emergency cardiopulmonary bypass support in patients with cardiac arrest

Emergency percutaneous cardiopulmonary bypass support was instituted in 11 patients in cardiac arrest refractory to conventional resuscitation measures. Emergency percutaneous cardiopulmonary bypass support was used in five patients in whom cardiac arrest occurred as a result of a complication in the cardiac catheterization laboratory (group 1) and in six other patients in cardiac arrest (group II). A 21F cannula and a 17F cannula were percutaneously inserted into the femoral vein and artery. Flow rates of 3 to 5 L/min were achieved with restoration of mean arterial pressure to 70 mm Hg (range 50 to 75). The status of all 11 patients was improved initially both clinically and hemodynamically with percutaneous cardiopulmonary bypass. Of the group II patients, three had anatomy unsuitable for percutaneous transluminal coronary angioplasty or coronary bypass grafting, could not be weaned from cardiopulmonary support, and died; three of these patients had coronary artery bypass grafting and two survived. All five group I patients underwent successful coronary bypass grafting and survived. Of the seven patients with anatomically correctable disease, all seven were discharged from the hospital. With conventional management nearly all seven of these patients would have died. Nine of 11 patients underwent a cardiac operation and seven of the nine survived. The operative mortality rate was 22% and the overall survival rate was 64%. At follow-up (mean 7 months), all seven patients are alive and six have resumed a normal and active life-style. In conclusion, emergency percutaneous cardiopulmonary bypass support is a powerful resuscitative tool that may stabilize the condition of patients in cardiogenic shock and cardiac arrest to allow for definitive intervention.     

体外循环心内直视手术中胰岛素抵抗的研究

目的　探讨体外循环 (CPB)中胰岛素抵抗 (IR)情况。方法　心脏直视手术患者 2 6例 ,分别测定其麻醉前、CPB前、CPB 15min、开放升主动脉后 5min和停CPB 2 0min的血胰岛素、C肽、生长激素、皮质醇、血糖和红细胞压积 ,计算胰岛素血糖比 (I/G)和胰岛素敏感性指数 [1/ (I×G) ]。结果　胰岛素、C肽、生长激素、皮质醇、血糖在CPB中和CPB后浓度均显著高于CPB前 (P <0 .0 1)。1/ (I×G)体外循环前为 0 .0 2 3 0 ,转机后CPB 15min、开放升主动脉后 5min和停CPB 2 0min分别为0 .0 0 2 1、0 .0 0 2 6、0 .0 0 2 9,与体外循环前相比有显著下降 (P <0 .0 1)。I/G体外循环前为 1.37,转机后CPB 15min、开放升主动脉后 5min和停CPB 2 0min分别为 2 .0 9、1.85、1.91,与体外循环前相比明显升高 (P <0 .0 5 )。结论　CPB中应激激素和血糖浓度增加明显 ,CPB期间存在明显的IR ,并且这些变化随应激刺激的增强而加强。