Procalcitonin dynamics, lactates, and haemoglobin serum levels might be a useful predictive tool of mortality in patients undergoing veno-venous extracorporeal oxygenation membrane support. Single centre experience

Background
Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is a well-established therapeutic option in respiratory failure refractory to mechanical ventilation. Due to the growing popularity of VV-ECMO, new methods to improve patient outcome are desired. This study aimed to evaluate the impact of patient age, sequential organ failure assessment score, respiratory ECMO survival prediction score, and early laboratory results on mortality of patients undergoing VV-ECMO.

Methods
The study population included 39 patients who underwent VV-ECMO between 2016 and 2019. The study compared the laboratory results during the first three days of therapy. The parameters included procalcitonin, C-reactive protein, haemoglobin, lactates, arterial blood partial pressure of carbon dioxide and oxygen.

Results
The decrease of procalcitonin by 10% between the 1st and the 3rd day was more often observed in the positive outcome group (71.4% vs. 38.9%, P = 0.041). Serum lactate concentrations at the 1st day corresponded with the negative outcome (AUC = 0.70, P = 0.026). The negative outcome group had a higher occurrence of serum lactates of 2 mmol L-1 at the 1st day (P = 0.039). The haemoglobin levels at the 1st and 3rd day corresponded with patients’ outcome (AUC = 0.69, P = 0.023 and AUC = 0.074, P = 0.006, respectively).

Conclusions
The study showed significant differences in early laboratory results between patients with a positive and negative outcome. In our opinion, serum lactate, haemoglobin and procalcitonin concentrations should be monitored daily to ensure an optimal therapeutic strategy and improve patient outcome. Our study provides valuable observations on predictive tools in VV-ECMO and possible directions for future research.