Unfavorable Outcomes Associated With Prolonged Ventilation in Stroke

Thomas Gattringer, MD, PhD, FESO

The results of a study evaluating patients who underwent thrombectomy for stroke suggests prolonged ventilation time predicts unfavorable outcomes at 3 months and must be performed as early as safely possible.

Of the 447 mechanical thrombectomy (MT) patients with stroke included in the study (mean age, 69.1 +13.3 years; 50.1% female), 188 (42.6%) of them had a favorable 3-month outcome, which correlated with shorter ventilation time (Spearman’s rho [r], 0.39;P <.001).

Data were collected by Thomas Gattringer, MD, PhD, FESO, researcher, clinical department of neuroradiology, vascular and interventional radiology, Medical University of Graz, and colleagues. Patients included in the study were at least <18 years and had received MT because of anterior circulation large vessel occlusion stroke (occlusion of the internal carotid and/or middle cerebral artery in the M1 and M2 segments) between January 2011 and April 2019. Each patient was under general anesthesia for the procedure.

Nineteen patients were excluded from the trial due to conscious sedation (n= 15) during MT or if they had a subsequent decompressive hemicraniectomy performed (n = 4).

As part of an ongoing thrombectomy cohort registry at the center (locate), Gattringer and colleagues gathered data such as duration of ventilation, the exact time point of extubation and early stroke complications within the neurointensive care unit or stroke unit. Early stroke complications such as pneumonia were recorded and defined by established criteria as the presence of infiltrate on chest X-ray, plus at least 2 of fever >38°C, leucocytosis or leukopenia and purulent secretions.

Researchers used a continuous variable to analyze the time from intubation to extubation.

Patients were divided into 3 subgroups in order to depict common clinical scenarios. They include “early” extubation within 6 hours, in order to encompass all patients extubated directed after the procedure or within the first hours of admission at the neurointensive care unit, “delayed” extubation occurring within 6—24 hours, and “late” extubation, or greater than 24 hours.

READ MORE: Improving Access to Endovascular Thrombectomy for Acute Ischemic Stroke

The primary outcome of the study was defined as a favorable neurological outcome at 3 months using the modified Rankin Scale (mRS). Favorable outcome was determined as scores between 0-2 versus unfavorable outcome measured as scores of 3—6.

In univariable analysis, unfavorable outcomes at 3 months were associated with the presence of arterial hypertension, chronic heart disease, diabetes mellitus, atrial fibrillation, and unsuccessful recanalization.

Patient characteristics showed that 65.3% (n = 288) of patients had an M1-segment occlusion of the middle cerebral artery and 58.6% (n = 258) had been treated with intravenous (IV) thrombolysis before MT. At admission, median National Institutes of Health Stroke Scale (NIHSS) was 15 (interquartile range, 11—18) and successful recanalization (defined as thrombolysis in cerebral infarction grades 2b–3) was achieved in 88.5% (n = 385) of the patients.

Favorable outcomes were observed in 42.6% (188 of 441 patients) of those with 3-month follow-up data. Median ventilation time was 3 hours (range, 1—530) and 85.5% (n = 382) of patients were extubated within 24 hours. Early, late and delayed extubation occurred in 57.5% (n = 258), 14.5% (n = 65), and 27.7% (n = 124) patients, respectively.

Frequency of concomitant heart disease was higher in patients with late extubation (30.8% vs 17.5%; P = .01), as well as an increase in severe strokes (median NIHSS, 17 vs 14; P <.001) and more frequently received IV thrombolysis (70.8% vs 56.2%; P = .03). Favorable function at 3 months was found in 7.8% (n = 5) of patients with late extubation.

At 3 months, researchers noted early extubation remained a significant predictor of favorable functional outcome (odds ratio [OR], 1.93; 95% CI 1.15—3.24; P = .01) together with successful recanalization (OR, 6.97; 95% CI 2.38—20.4).

“Whilst it was not surprising that patients with late extubation (>24 h) had worse outcomes, the most interesting and novel finding of our work was the independent prognostic effect of early extubation within the first 24 h,” the study authors concluded.

REFERENCE

Hofler-Fandler S, Heschl S, Kneihsl M, et al. Ventilation time and prognosis after stroke thrombectomy: the shorter, the better! Eur J Neurol. Published online February 17, 2020. doi: 10.1111/ene.14178