Long-term outcomes from home invasive mechanical ventilation (HIMV) in Queensland

Home invasive mechanical ventilation (HIMV) is a life-sustaining therapy for patients with chronic respiratory insufficiency. The published literature is inconsistent, reflecting varied practices. A retrospective review of patients treated with HIMV at a single tertiary centre between 01/01/2005 and 18/05/2024 was conducted. Primary outcome was the time from HIMV initiation to cessation or death. Secondary outcomes included cause of death, number of hospitalisations, and length of stay. Patient demographics and baseline characteristics were recorded. Cox proportionate hazard regression models were used to assess the associations between survival and baseline characteristics. Thirty-one patients were identified, 26 meeting inclusion criteria. Median age at injury was 35 years (IQR = 20.75-56), with 15 (57 %) males. Thirteen (50 %) patients had spinal cord injuries, four (15 %) had brain injuries, two (8 %) had restrictive thoracic injuries, five (19 %) had neuromuscular conditions, and two (8 %) had other conditions. The mean survival on HIMV therapy was 19.6 years (95 % CI: 13.8-25.4). Cause of death was predominantly respiratory failure (4, 36 %), followed by cardiovascular disease (3, 27 %). Body mass index (BMI) > 25kg/m2 (hazard ratio, HR 11.87 (95 % CI: 2.2-57.5, p = 0.01) and expiratory positive airway pressure (EPAP). >6cmH2O (HR 15.5, 95 % CI: 1.7-146.2, p = 0.02) were associated with worse survival, however only BMI remained significant in multivariate analysis. This study details the unique characteristics of HIMV in Queensland, further demonstrating the heterogeneity in international practice. Additionally, BMI > 25 kg/m2 was identified as a potentially modifiable risk factors which was associated with poorer survival outcomes.