Exposure to severe hyperoxemia worsens survival and neurological outcome in patients supported by veno-arterial extracorporeal membrane oxygenation: A meta-analysis.

BACKGROUND: Veno-arterial Extracorporeal Membrane Oxygenation (VA-ECMO) is a rescue treatment in refractory cardiogenic shock (CS) or refractory cardiac arrest (CA). Exposure to hyperoxemia is common during VA-ECMO, and its impact on patient's outcome remains unclear. METHODS: We conducted a systematic review (PubMed and Scopus) and meta-analysis investigating the effects of exposure to severe hyperoxemia on mortality and poor neurological outcome in patients supported by VA-ECMO. When both adjusted and unadjusted Odds Ratio (OR) were provided, we used the adjusted one. Results are reported as OR and 95% confidence interval (CI). Subgroup analyses were conducted according to VA-ECMO indication and hyperoxemia thresholds. RESULTS: Data from 10 observational studies were included. Nine studies reported data on mortality (n = 5 refractory CA, n = 4 CS), and 4 on neurological outcome. As compared to normal oxygenation levels, exposure to severe hyperoxemia was associated with higher mortality (nine studies; OR: 1.80 [1.16-2.78]; p = 0.009; I2 = 83%; low certainty of evidence) and worse neurological outcome (four studies; OR: 1.97 [1.30-2.96]; p = 0.001; I2 = 0%; low certainty of evidence). Magnitude and effect of these findings remained valid in subgroup analyses conducted according to different hyperoxemia thresholds (>200 or >300 mmHg) and VA-ECMO indication, although the association with mortality remained uncertain in the refractory CA population (p = 0.13). Analysis restricted to studies providing adjusted OR data confirmed an increased likelihood of poorer neurological outcome (three studies; OR: 2.11 [1.32-3.38]; p = 0.002) in patients exposed to severe hyperoxemia but did not suggest higher mortality (five studies; OR: 1.68 [0.89-3.18]; p = 0.11). CONCLUSIONS: Severe hyperoxemia exposure after initiation of VA-ECMO may be associated with an almost doubled increased probability of poor neurological outcome and mortality. Clinical efforts should be made to avoid severe hyperoxemia during VA-ECMO support.

Mortality in patients with septic cardiomyopathy identified by longitudinal strain by speckle tracking echocardiography: An updated systematic review and meta-analysis with trial sequential analysis.

BACKGROUND: Septic cardiomyopathy is associated with poor outcomes but its definition remains unclear. In a previous meta-analysis, left ventricular (LV) longitudinal strain (LS) showed significant prognostic value in septic patients, but findings were not robust due to a limited number of studies, differences in effect size and no adjustment for confounders. METHODS: We conducted an updated systematic review (PubMed and Scopus up to 14.02.2023) and meta-analysis to investigate the association between LS and survival in septic patients. We included studies reporting global (from three apical views) or regional LS (one or two apical windows). A secondary analysis evaluated the association between LV ejection fraction (EF) and survival using data from the selected studies. RESULTS: We included fourteen studies (1678 patients, survival 69.6%) and demonstrated an association between better performance (more negative LS) and survival with a mean difference (MD) of -1.45%[-2.10, -0.80] (p < 0.0001;I2 = 42%). No subgroup differences were found stratifying studies according to number of views used to calculate LS (p = 0.31;I2 = 16%), severity of sepsis (p = 0.42;I2 = 0%), and sepsis criteria (p = 0.59;I2 = 0%). Trial sequential analysis and sensitivity analyses confirmed the primary findings. Grade of evidence was low. In the included studies, thirteen reported LVEF and we found an association between higher LVEF and survival (MD = 2.44% [0.44,4.45]; p = 0.02;I2 = 42%). CONCLUSIONS: We confirmed that more negative LS values are associated with higher survival in septic patients. The clinical relevance of this difference and whether the use of LS may improve understanding of septic cardiomyopathy and prognostication deserve further investigation. The association found between LVEF and survival is of unlikely clinical meaning. REGISTRATION: PROSPERO number CRD42023432354.