Outcomes of weaning from mechanical ventilation after spinal cord injury: a systematic review and meta-analysis

Background: Prolonged need for mechanical ventilation (MV) greatly impacts life expectancy and quality of life of patients after spinal cord injury (SCI). Outcomes related to weaning from MV have not been systematically assessed. We aimed to evaluate the probability of weaning success, duration of MV and mortality after SCI. Methods: We searched five databases from inception until January 2020 for observational studies and randomized-controlled trials (RCTs) enrolling adult patients (>16 years) with SCI from any cause requiring MV. Synthetic results are reported as meta-analytic means and proportions, based on random effects models. The study is registered with PROSPERO (CRD42020156788). Results: 36 studies (8492 patients, mean age 42.5), including 35 retrospective cohort studies and 1 RCT, were selected. Cervical lesions were predominant (6658 patients had cervical lesions only, 1726 in association with other levels’ lesions); 24 studies were conducted in Intensive Care Units (ICUs), 12 in rehabilitative settings. In ICU, mean time from injury to hospitalization was 7.5h [6.6–8.5], mean duration of MV 27.8 days [20.1–35.4], probability of weaning success 64.8% [48.5–78.3] and mortality 7.7% [5.1-11.4]. Patients transferred to rehabilitation centres were at 36.6 days [23.1–50.1] from injury and were ventilated for a mean of 45 days [26.3–63.8]; 71.1% [48.2–86.6] of them were successfully weaned, while mortality was 0.8% [0-18.5]. Conclusions: Around 65% of MV patients can be weaned in ICU after SCI; a further gain in weaning success can be obtained during rehabilitation, with minimal increase in mortality. Predicting these outcomes needs further research.