The Feasibility of High-Intensity Interval Training in Patients with Intensive Care Unit-Acquired Weakness Syndrome Following Long-Term Invasive Ventilation

BACKGROUND: Intensive care unit-acquired weakness syndrome (ICUAWS) can be a consequence of long-term mechanical ventilation. Despite recommendations of early patient mobilisation, little is known about the feasibility, safety and benefit of interval training in early rehabilitation facilities (ERF) after long-term invasive ventilation. METHODS AND RESULTS: We retrospectively analysed two established training protocols of bicycle ergometry in ERF patients after long-term (> 7 days) invasive ventilation (n = 46). Patients conducted moderate continuous (MCT, n = 24, mean age 70.3 ± 10.1 years) or high-intensity interval training (HIIT, n = 22, mean age 63.6 ± 12.6 years). The intensity of training was monitored with the BORG CR10 scale (intense phases ≥ 7/10 and moderate phases ≤ 4/10 points). The primary outcome was improvement (∆-values) of six-minute-walk-test (6 MWT), while the secondary outcomes were improvement of vital capacity (VC(max)), forced expiratory volume in 1 s (FEV(1)), maximal inspiratory pressure (PI(max)) and functional capabilities (functional independence assessment measure, FIM/FAM and Barthel scores) after 3 weeks of training. No adverse events were observed. There was a trend towards a greater improvement of 6 MWT in HIIT than MCT (159.5 ± 64.9 m vs. 120.4 ± 60.4 m; p = .057), despite more days of invasive ventilation (39.6 ± 16.8 days vs. 26.8 ± 16.2 days; p = .009). VC(max) (∆0.5l ± 0.6 vs. ∆0.5l ± 0.3; p = .462), FEV(1) (∆0.2l ± 0.3 vs. ∆0.3l ± 0.2; p = .218) PI(max) (∆0.8 ± 1.1 kPa vs. ∆0.7 ± 1.3pts; p = .918) and functional status (FIM/FAM: ∆29.0 ± 14.8pts vs. ∆30.9 ± 16.0pts; p = .707; Barthel: ∆28.9 ± 16.0 pts vs. ∆25.0 ± 10.5pts; p = .341) improved in HIIT and MCT. CONCLUSIONS: We demonstrate the feasibility and safety of HIIT in the early rehabilitation of ICUAWS patients. Larger trials are necessary to find adequate dosage of HIIT in ICUAWS patients. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40798-021-00299-6.