Coupled extracorporeal CO2 removal and Continuous Renal Replacement Therapy for the treatment of multiorgan failure in a pregnant woman with COVID-19: a case report

ABSTRACT

Background: Lung-protective ventilation (LPV) with low tidal volumes (TV), aimed to reduce ventilator-induced lung injury, is one of the cornerstones in the treatment of acute respiratory distress syndrome (ARDS), including that secondary to Coronavirus disease 2019 (COVID-19). To allow LPV, and avoid the risk of progressive hypercapnia and respiratory acidosis, a wide range of extracorporeal CO2 removal (ECCO2R) techniques have been developed. These treatments may be performed alone or in combination with other organ support therapies. Here, we report our experience with a pregnant woman with multiorgan failure (MOF), occurring as a sequela of COVID-19, who was successfully treated with ECCO2R coupled with continuous renal replacement therapy (CRRT). Case Presentation A 34-year-old pregnant patient at the 16th gestational week affected by COVID-19 was admitted for dyspnea, rapidly complicated by MOF. Because of concomitant hypercapnia and acute kidney injury the patient was treated with an ECCO2R membrane inserted in series after a hemofilter in a common CRRT platform. ECCO2R was provided using a polymethyl pentene, hollow fiber, gas-exchanger membrane of 1.35 m2. ECCO2R+CRRT was set in continuous venovenous hemodialysis (CVVHD) mode with blood flow of 300 mL/min and a sweep gas blood flow of 5 l/min. Systemic anticoagulation was obtained by continuous administration of unfractionated heparin (UFH), with a target activated partial thromboplastin time (aPTT) of 70-80 seconds. (In table 1, ventilatory and hemodynamic parameters collected during ECCO2R+CRRT treatment are reassumed). The combined treatment was effective in reducing hypercapnia, allowing the maintenance of LPV. Moreover, it was associated with the hemodynamic stability of both mother and fetus and it was well-tolerated. Anyway, the treatment was complicated by minor bleeding episodes mainly linked to the anticoagulation required to maintain the patency of the extracorporeal circuit. After ECCO2R+CRRT termination, the patient progressively recovered pulmonary and kidney function, so that it was possible to withdraw any support therapy. Moreover, she underwent a preterm spontaneous vaginal delivery of an alive baby. Conclusion(s) Our case supports the use of ECCO2R+CRRT as a suitable approach in complex patients, including those with severe COVID-19, being aware of the potential complications linked to this treatment.