Outcome of ECMO and CRRT , experience of Hospital University MED VI , Oujda , Morocco

younes oujidi (  younesoujidi@gmail.com ) Centre Hospitalier Universitaire Mohammed VI ounci Essad Centre Hospitalier Universitaire Mohammed VI Inass Arhoun El haddad; Centre Hospitalier Universitaire Mohammed VI amine Bensaid Centre Hospitalier Universitaire Mohammed VI imane Melhaoui Centre Hospitalier Universitaire Mohammed VI layla Kherroubi Centre Hospitalier Universitaire Mohammed VI houssam Bkiyar Centre Hospitalier Universitaire Mohammed VI yassamine Bentata Centre Hospitalier Universitaire Mohammed VI Housni Brahim Centre Hospitalier Universitaire Mohammed VI

predominance (sex ratio (M/F) of 3.28). Over one third of the patients had comorbidities, Diabetes mellitus was the most common (30%), followed by hypertension (17%). 83.3% of our patients bene tted from a veno-venous type of ECMO; and ARDS was the most frequent cause for using ECMO comparing to cardiac failure (90% vs 16.6%). 63.3% of our ECMO-using patients developed an AKI, with a mean creatinine peak of 28.74mg/L. 36.6% of our ECMO-using patients required the use of a continuous renal replacement therapy (CRRT). Unfortunately, all our ECMO-using patients complicated with AKI died, with a mortality rate of 100%.
Conclusion: Among patients receiving ECMO, the incidence rates of AKI and severe AKI requiring CRRT are high, regardless of their prior medical conditions and the technique used to connect ECMO and CRRT.

Main Text
Extracorporeal membrane oxygenation (ECMO) is a technique that has improved the prognosis of patients with refractory hypoxemia or cardiac failure, unfortunately this therapy can be complicated by Acute Kidney injury (AKI) which may need Continuous renal replacement therapy (CRRT).
Although the effects of CRRT have been widely studied, the impact of simultaneous CRRT and ECMO is less well described.
We aimed to de ne the incidence of concomitant CRRT with ECMO therapy and to determine the overall impact of this strategy on patient outcomes such as mortality and renal recovery.
We retrospectively analyzed data of patients of all ages, genders and ethnicities, All enrolled patients or their families have been informed that data from their ICU experience may be collected for research purposes, admitted in the intensive care unit of Mohammed VI University Hospital, Oujda, Morocco, on a cumulative period of 2 years (from January 2019 to December 2020). Patients enrolled in the study must have bene ted from ECMO during their stay, and presented an acute kidney injury afterwards. Were excluded: patients who developed AKI before bene tting from ECMO and/or missing data (ex. duplicated records, empty or incomplete les). We excluded: patients who developed AKI before bene tting from ECMO and/or missing data (ex. duplicated records, empty or incomplete les).
We used 'Microsoft Excel' as a software to utilize the information collected from the computerized patient database. This study has been approved by the clinicaltrials Ethics Committee under Number NCT05033509.
Our data comprised a total of 30 patients that were included in the nal study ;The mean age was 59.8 ± 12.7 years, ranging from 19 to 87 years. Our patients were mainly males, with a sex ratio (M/F) of 3.28.
Over one third of the patients had comorbidities, Diabetes mellitus was the most common (30%), followed by hypertension (17%). 83.3% of our patients bene tted from a veno-venous type of ECMO; and ARDS was the most frequent cause for using ECMO comparing to cardiac failure (90% vs 16.6%). All the 30 patients had their creatinine levels and their diuresis status monitored daily. 63.3% of our ECMO-using patients developed an AKI, de ned by the KDIGO guidelines, and staged (1 to 3) following the KDIGO staging of AKI severity. The mean creatinine peak was 28.74mg/L (N.R: 5.7 -11 for female patients, and 7.2 -12.5 for male patients).

36.6% of our ECMO-using patients required the use of a continuous renal replacement therapy (CRRT).
Unfortunately, all our ECMO-using patients complicated with AKI died, with a mortality rate of 100%.
( Tables 1, 2,3) While using ECMO, AKI is a very common complication (incidence: 52 -85%) and usually requiring Renal Replacement Therapy (45%) [1]. The most common reasons for initiating dialysis with ECMO are uid overload (43%), prevention of uid overload (16%), AKI (35%) and electrolyte disturbances (4%) [3]. The Mortality under ECMO and CRRT is signi cantly higher and goes up to 80% (RR: 4.99) [1][2] . There are three ways that CRRT can be initiated in a patient undergoing treatment with ECMO, The most common technique is using separate vascular access and circuit for CRRT and ECMO [2] ,but The safest and most accurate way to combine the two developed so far is to connect an external CRRT machine (commonly used in an ICU) to its own circuit, an ECMO circuit. This approach is becoming increasingly popular, especially with continuous venous Hemo ltration (CVVH) , continuous venous hemodia ltration (CVVHDF), and continuous venous hemodialysis (CVVHD); it allows a precise control of blood ow in the CRRT cycle with proper control of transmembrane pressure (TMP) and precise uid balance. [3][4] The results were similar to those described in the literature. It was found that the majority of our patients undergoing ECMO therapy presented an AKI (19 out of 30; 63.3%); and the majority of ECMO-patients with an AKI required a CRRT (11 out of 19; 57.8%).This highlights the need for multisystem knowledge and an interdisciplinary approach in the care of ill patients requiring the use of ECMO therapies. congruent with literature data where mortality rates varied between 60-100%; studies also showed a 3.7fold increased risk of hospital mortality among ECMO patients with severe AKI requiring RRT. [1,5]. Future studies should focus on strategies for prediction, detection, and prevention of AKI among ECMO patients.