The Effects of Zero-Balance Ultrafiltration on Postoperative Recovery after Cardiopulmonary Bypass: A Meta-Analysis of Randomized Controlled Trials

OBJECTIVE:

Considered as a significant
ultrafiltration technology during cardiopulmonary bypass (CPB),
zero-balance ultrafiltration (Z-BUF) has always received controversial
support regarding its effectiveness in reducing inflammatory mediators
in plasma. Therefore, we conducted a meta-analysis to evaluate the
clinical effect of Z-BUF through screening all relevant published
randomized controlled trials (RCTs).

METHODS:

A
comprehensive search was conducted to screen all RCTs of Z-BUF. Three
trained investigators searched databases, including PubMed, Embase, the
Cochrane Library, Google scholar, and Chinese literature databases
(CNKI, WanFang, WeiPu). RCTs that compared Z-BUF with
non-ultrafiltration were included. We focused on clinical outcomes such
as length of stay in ICU, duration of ventilation, hospital stay, total
amount of chest tube drainage and mortality. Finally, a total of 7
studies containing appropriate criteria were divided into an adult group
and a pediatric group. A random effects model was used to calculate
weighted mean difference with 95% confidence intervals.

RESULTS:

In
the adult group, the benefits of Z-BUF in duration of ventilation
(WMD=-2.77, 95% CI = [-6.26, 0.72], I(2)=71%, p=0.12) and the length of
ICU stay (WMD=-4.13, 95% CI = [-10.09, 1.84], I(2)=77%, Z=1.36, p=0.17)
were not apparent, with significant heterogeneity existing in the
statistical results. The rest of the clinical parameters could not be
evaluated due to insufficient data. In the pediatric group, combined
analysis showed Z-BUF could reduce the duration of mechanical
ventilation (WMD=3.07; 95%CI= [-7.56, -3.46], I(2)=17%, p=0.27). The
advantage of Z-BUF was not observed in other clinical outcomes.

CONCLUSION:

The
benefits of Z-BUF were not apparent, according to the report. Further
studies involving combined ultrafiltration are expected to provide
improved ultrafiltration during CPB.