Intermittent Cold-Blood Cardioplegia and Its Impact on Myocardial Acidosis during Coronary Bypass Surgery.

BACKGROUND: The purpose of the study was to assess the degree of myocardial acidosis in patients undergoing elective coronary bypass surgery, in whom intermittent cold-blood cardioplegia (ICBC) was used for myocardial protection. The results of this study are presented in comparison to those of a previous trial conducted by the same investigators, using a similar methodology, but with intermittent warm-blood cardioplegia (IWBC). PATIENTS AND METHODS: In 15 patients undergoing elective myocardial revascularization with ICBC for myocardial protection, metabolic changes of global ischemia indicators, lactate and pH values (measured simultaneously in coronary sinus and arterial blood) were analyzed. Lactate concentrations and pH values were measured at the beginning and the end of each cardioplegia administration, and the change-overtime analysis of the values was performed. For comparison with the results of the previous study (IWBC method) consisting of 12 patients, the analysis of variance with repeated measurements, including tests for a crossover, group, and time effect were used. RESULTS: Using the ICBC method, as compared with IWBC, no significant difference in the lactate production was observed during the first two successive cardioplegia administrations. During the third and fourth administrations, especially at the end of reperfusions, ICBC patients had a significantly lower lactate release and higher pH values, as compared with IWBC patients. CONCLUSION: Our results suggest that ICBC has an inhibiting effect on potentially progressive myocardial acidosis during cross-clamp period.

A Suprainstitutional Network for Remote Extracorporeal Life Support: A Retrospective Cohort Study.

OBJECTIVES: This study sought to evaluate patient outcome within the Düsseldorf Extracorporeal Life Support (ECLS) Network, a suprainstitutional network for rapid-response remote ECLS and to define survival-based predictors. BACKGROUND: Mobile venoarterial extracorporeal membrane oxygenation (vaECMO) used for ECLS has become a treatment option for a patient population with an otherwise fatal prognosis. However, outcome data remain scarce and institutional standards required to manage these patients are still poorly defined. METHODS: This retrospective cohort study analyzes the outcome of 115 patients consecutively treated between July 2011 and October 2014 within the Düsseldorf ECLS Network due to refractory circulatory failure. RESULTS: Of the 115 patients (56 ± 15 years of age, vaECMO initiation under cardiopulmonary resuscitation [CPR] 77%, CPR duration 45 [range 5 to 90] min), 50 patients (44%) survived to primary discharge and 38 patients (33%) were alive after a median follow-up of 1.5 years (95% confidence interval [CI]: 1.2 to 1.7). Thirty-seven (97%) of the long-term survivors showed a favorable neurological outcome. Risk factors associated with mortality during vaECMO were CPR duration (hazard ratio [HR]: 1.006; 95% CI: 1.00 to 1.01) and ischemic stroke (HR: 2.63; 95% CI: 1.52 to 4.56). Risk factors associated with mortality after vaECMO weaning were renal failure (HR: 6.60; 95% CI: 2.72 to 16.01) and sepsis (HR: 3.6; 95% CI: 1.50 to 8.69). Visceral ischemia had a negative impact (HR: 0.30; 95% CI: 0.11 to 0.84) whereas assist device implantation promoted successful vaECMO weaning (HR: 2.95; 95% CI: 1.65 to 5.25). Further, 3 distinct risk groups with significant differences in survival could be identified, demonstrating that in patients with no or short CPR mortality was not conditioned by age, whereas in patients with prolonged CPR young age was associated with increased survival. CONCLUSIONS: This study illustrates the implementation of a suprainstitutional ECLS Network. Further, our data suggest that mobile vaECMO is beneficial for a larger patient population than actually expected, especially regarding young patients presenting with prolonged CPR or patients regardless of age with no or short CPR.

Metabolic monitoring of postischemic myocardium during intermittent warm-blood cardioplegic administration.

In 12 patients undergoing elective myocardial revascularization with intermittent administration of warm-blood cardioplegic solution for myocardial protection, we analyzed metabolic changes by assay of global ischemia indicators (pH, lactate, glucose, and potassium), which we measured in the coronary sinus and arterial blood during the ischemic and postischemic periods. A typical cumulative ischemic pattern with progressively decreasing pH values and progressively increasing lactate values could not be observed in all patients. It was not the degree of lactate washout, but the lactate concentration at the end of each reperfusion, that correlated significantly with global metabolic recovery time, which suggests the importance of effective reperfusion.