In patients with cardiogenic shock (CS) who required invasive mechanical ventilation (IMV), rates of failed extubation were similar to patients with other critical illnesses, according to a study published July 23 in JACC: Advances. While transition to minimal ventilator support within 24 hours of intubation was common, hemodynamic instability routinely delayed spontaneous breathing trials and extubation.

Christopher S. Grubb, MD, et al., looked retrospectively at 105 patients with CS that required IMV at a single hospital from 2017 to 2023. Among the CS cohort, 37% were intubated due to ongoing cardiac arrest and 32% due to hypoxic respiratory failure. Outcomes of interest included in-hospital mortality, survival to extubation and reintubation.

Results showed 62% of patients were extubated after a median of 4.8 days. Overall, 49% of patients who received temporary mechanical circulatory support survived, which was removed before extubation in 98% of cases. Additionally, reintubation was observed in 14% of patients within 48 hours, and 41% of patients died in the hospital.

"Patients with cardiac disease are known to be at higher risk of reintubation, so the relatively low reintubation rate in our study raises the question of whether IMV could safely have been discontinued earlier," write the authors.

Grubb and colleagues also note that spontaneous breathing trials were delayed in 78% of patients, and in 82% of these instances, hemodynamic instability was to blame.

In an accompanying editorial comment, P. Elliott Miller, MD, MHS; Omar El Charif, MD; and Mark Jacobs, MD, MBA, MS, acknowledge this single-center study, while presenting a "treasure trove of information," may not be "generalizable to other institutions." They advise that "next steps should include characterization across multiple centers, potentially through the creation of registries specific to respiratory failure in the [cardiac intensive care unit]."

More research coming out of JACC: Advances explores the optimal veno-arterial extracorporeal life support (VA-ECLS) for patients with mixed cardiogenic and septic shock. Lyana Labrada, MD, et al., found that providing higher support at 24 hours trended toward increased survival to discharge vs. lower support, however these results were not statistically significant.

Using data from the Extracorporeal Life Support Organization database, the authors included 452 adult patients in mixed shock requiring VA-ECLS between 2017 and 2022. Patients with <2.2 L/min/m² flow circulatory support 24 hours after ECLS initiation were classified as lower support while patients with ≥2.2 L/min/m² flow circulatory support were classified as higher support.

Overall, 63% of patients analyzed died, and increased risk of mortality was observed with older age, pre-extracorporeal membrane oxygenation cardiac arrest and baseline Charlson Comorbidity Index.

Comparing patients with higher vs. lower support, 43% and 34% survived to discharge, respectively (p=0.063), with higher VA-ECLS flow at 24 hours seeing a trend toward improved survival at discharge (adjusted odds ratio: 1.31; 95% CI: 0.87-1.97; p=0.19).

"While not statistically significant, it is also noteworthy the survivors were more likely to be at higher (>25 ECMO runs/year) volume centers compare to low (<10 ECMO runs/year) volume centers, highlighting the importance of clinical experience in the management of mixed shock patients," the authors add.

An accompanying editorial comment authored by Alastair G. Proudfoot, MD, PhD; Peter McGuigan, MD; and Alex Warren, MD, state that "given the documented rising use of ECMO for the indication of mixed shock, it is vital that we seek to optimize our approach to patient selection and management." However, they question the ability of the authors to "reliably interrogate this key question within the available data set."