(5-9)
Another option for severe refractory ARDS patients is venovenous
extracorporeal membrane oxygenation (ECMO) which is considered as a
rescue therapy. ECMO appeared to
be beneficial during the influenza A (H1N1) pandemic back in 2009, with
a mortality rate of 21% (10). In another observational
study on patients with H1N1 related ARDS, the mortality rate was 23.7%
for ECMO patients in versus 52.5% for non ECMO patients
(11). In 2018, a retrospective study was conducted on
middle east respiratory syndrome (MERS) patients with refractory ARDS
and showed that ECMO should be used as a rescue therapy because it is
associated with lower mortality when compared to conventional mechanical
ventilation group (65 vs. 100%, P = 0.02) (12). No ECMO
report was published on SARS (coronavirus emerging in 2002) related
ARDS.
The role of ECMO in the management
of COVID- 19 ARDS remains unclear.
The initial reports of using
venovenous ECMO with COVID- 19 patients suffering from intractable
hypoxemia observed a high mortality rate and recommended using ECMO with
caution in the current pandemic (13). According to the
interim guidance made by the World Health Organization (WHO), venovenous
ECMO could be considered as a salvage therapy for COVID-19 with
refractory hypoxemia in expert centers with enough cases to ensure
clinical expertise (14) .
In view of the current growing pandemic and the fact that only a little
experience with using ECMO to support COVID-19 patients is available, we
aimed to estimate the effect of venovenous ECMO on mortality from
COVID-19 patients with respiratory failure via all available studies by
performing a systematic review and meta-analysis.