Blood lactate normalization following venoarterial ECMO institution for refractory cardiogenic shock

Cerebral Oxygenation as a Monitoring Parameter for Mortality During Venoarterial Extracorporeal Membrane Oxygenation

There are no recommended guidelines for monitoring parameters during venoarterial extracorporeal membrane oxygenation (V-A ECMO). We evaluated whether regional cerebral oxygen saturation (rScO2) could be a monitoring parameter for mortality during V-A ECMO. We retrospectively searched our database for adult patients who underwent V-A ECMO between April 2015 and October 2016 and identified 21 patients with rScO2 data. Their baseline and clinical characteristics during the first 7 days (vital signs, arterial blood gas results, ECMO variables, rScO2, Swan-Ganz catheter parameters, transthoracic echocardiography parameters, and outcomes) were collected and evaluated for associations with 28 day mortality. The survivor group (12 patients, 57.1%) had higher rScO2 values and lower lactate levels, compared with the nonsurvivor group (nine cases, 42.9%) during the first 7 days. The areas under the receiver operating characteristics curves were 0.87 for right rScO2 (p < 0.001) and 0.86 for left rScO2 (p < 0.001). The optimal cutoff values for right and left rScO2 were 58% (sensitivity: 78.7%, specificity: 83.3%) and 57% (sensitivity: 80.0%, specificity: 70.8%), respectively. Kaplan-Meier analysis revealed that the risks of 28 day mortality were higher among patients with a right rScO2 of <58% and a left rScO2 of <57%, compared with patients with a right rScO2 of ≥58% and a left rScO2 of ≥57% (both, p < 0.001). We suggest that rScO2 may be used as a monitoring parameter for 28 day mortality among patients undergoing V-A ECMO.

Prognostic Value of Blood Lactate and Lactate Clearance in Refractory Cardiac Arrest Treated by Extracorporeal Life Support

OBJECTIVE

During cardiac arrest (CA) resuscitation, an 'ischaemia-reperfusion' syndrome occurs leading to multiorgan failure reflected by an increase in blood lactate. Blood lactate is a diagnosis and prognosis biomarker in extracorporeal life support (ECLS), but its kinetic appears more informative to assess a patient's outcome. The aim of the present study was to describe the prognostic value of blood lactate and lactate clearance (LC) 3 (H3) and 6 h (H6) after the initiation of ECLS in the treatment of refractory CA.

METHODS

Patients admitted to the intensive care unit for refractory CA were included. Lactate measurements were performed at the initiation of ECLS (H0) and at H3 and H6 upon the initiation of ECLS. LC was measured from 0 to 3 h (LC03), 0 to 6 h (LC06) and 3 to 6 h (LC36). The primary endpoint was in-hospital mortality within 28 days.

RESULTS

Sixty-six patients were enrolled in the study. Lactate levels were higher in deceased patients. Increased mortality was observed with increasing levels of lactate at H3 and H6 and with decreasing LC03. Using logistic regression, an association was observed between mortality and lactate at H3 with an odds ratio (OR) of 1.21 (95% confidence interval (CI) 1.05-1.42); LC03, OR of 0.93 (95% CI 0.87-0.99) and LC06, OR of 0.96 (95% CI 0.92-0.99).

CONCLUSION

Blood lactate and LC within the first 3 h of ECLS in refractory CA are associated with mortality. LC is a more relevant parameter than blood lactate, taking into account both the production and elimination of lactate. We suggest to preferentially use LC to assess the patient's outcome.

Development and validation of a prognostic model for survival in patients treated with venoarterial extracorporeal membrane oxygenation: the PREDICT VA-ECMO score

Aims:

Several scoring systems have been introduced for prognostication after initiating venoarterial extracorporeal membrane oxygenation (VA-ECMO) therapy. However, static scores offer limited guidance once VA-ECMO is implanted, although continued allocation of healthcare resources is critical. Patients requiring continued VA-ECMO support are extremely unstable, with minimal heart function and multi-organ failure in most cases. The aim of the present study was to develop and validate a dynamic prognostic model for patients treated with VA-ECMO.

Methods and results:

A derivation cohort included 205 all-comers undergoing VA-ECMO implantation at a tertiary referral hospital (51% received VA-ECMO during resuscitation and 43% had severe shock). Two prediction models based on point-of-care biomarkers were developed using penalised logistic regression in an elastic net approach. A validation cohort was recruited from an independent tertiary referral hospital. Comparators for the prediction of hospital survival were the SAVE score (area under the receiver operation characteristic curve (AUC) of 0.686), the SAPS score (AUC 0.679), the APACHE score (AUC 0.662) and the SOFA score (AUC 0.732) in 6-hour survivors. The 6-hour PREDICT VA-ECMO score (based on lactate, pH and standard bicarbonate concentration) outperformed the comparator scores with an AUC of 0.823. The 12-hour PREDICT VA-ECMO integrated lactate, pH and standard bicarbonate concentration at 1 hour, 6 hours and 12 hours after ECMO insertion allowed even better prognostication (AUC 0.839). Performance of the scores in the external validation cohort was good (AUCs 0.718 for the 6-hour score and 0.735 for the 12-hour score, respectively).

Conclusion:

In patients requiring VA-ECMO therapy, a dynamic score using three point-of-care biomarkers predicts hospital mortality with high reliability. Furthermore, the PREDICT scores are the first scores for extracorporeal cardiopulmonary resuscitation patients.