Objective
To characterize the pressures, resistances, oxygenation, and decarboxylation
efficacy of two oxygenators associated in series or in parallel during
venous-venous extracorporeal membrane oxygenation support.
Methods
Using the results of a swine severe respiratory failure associated with
multiple organ dysfunction venous-venous extracorporeal membrane oxygenation
support model and mathematical modeling, we explored the effects on
oxygenation, decarboxylation and circuit pressures of in-parallel and
in-series associations of oxygenators.
Results
Five animals with a median weight of 80kg were tested. Both configurations
increased the oxygen partial pressure after the oxygenators. The return
cannula oxygen content was also slightly higher, but the impact on systemic
oxygenation was minimal using oxygenators with a high rated flow (~
7L/minute). Both configurations significantly reduced the systemic carbon
dioxide partial pressure. As the extracorporeal membrane oxygenation blood
flow increased, the oxygenator resistance decreased initially with a further
increase with higher blood flows but with a small clinical impact.
Conclusion
Association of oxygenators in parallel or in series during venous-venous
extracorporeal membrane oxygenation support provides a modest increase in
carbon dioxide partial pressure removal with a slight improvement in
oxygenation. The effect of oxygenator associations on extracorporeal circuit
pressures is minimal.
Background
Whether fasting early in critical illness course is acceptable is not clear and high‐quality data on this topic are lacking. To generate equipoise for future clinical trials and bring additional data to current literature, we compared outcomes of patients fasted during the first 72 h of intensive care unit (ICU) stay to patients receiving any nutrition support during this period.
Methods
Retrospective cohort study of a medical ICU from a tertiary academic center in Brazil. Adult patients treated between November 2017 and February 2022 with an ICU length of stay of ≥5 days were included. Baseline and daily data were retrieved from the prospectively collected administrative database. We did 1:1 propensity score matching to compare patients fasting for at least 72 h with controls. Primary outcome was hospital mortality and secondary outcomes were other resources' use.
Results
During the study period, 1591 patients were cared for in this ICU, of which 998 stayed ≥5 days. After excluding readmissions and propensity score matching, 93 patients in the fasting group were matched to 93 controls. Hospital mortality was similar between fasting and matched control groups (odds ratio = 1.04; 95% CI = 0.56–1.94; P > 0.99). Secondary outcomes were not different between groups, including length of stay, days on mechanical ventilation, and incidence of new infections.
Conclusion
Withholding nutrition support in the first 72 h of ICU stay was not associated with worse outcomes in this cohort of severe critically ill patients.
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