Survival Rates for Patients in a Chilean National Home Mechanical Ventilation Program

A study of a national Chilean home ventilation program for adult patients with chronic respiratory failure characterized the prevalence, common diagnoses, and survival rates in patients enrolled between 2008 and 2018. The study findings were reported in BMC Pulmonary Medicine.

In the study, researchers evaluated data from a prospective cohort of patients with chronic respiratory failure who participated in the program. Data that were characterized and assessed included disease characteristics, mode of admission, quality of life, time in the program, and survival.

The study included 1105 patients (median age, 59 years; 58.1% women; mean body mass index, 34.9 kg/m²). Diagnoses causing hypoventilation across the population included chronic obstructive pulmonary disease (COPD; n=388), obesity hypoventilation syndrome (OHS; n=264), neuromuscular disease (NMD; n=180), noncystic fibrosis (non-CF) bronchiectasis or tuberculosis (n=92), scoliosis (n=65), amyotrophic lateral sclerosis (ALS; n=58), and “other” diagnoses (n=58).

A total of 842 patients started home mechanical ventilation in the chronic stable mode, while 263 patients started in the acute mode. Patients were further categorized based on receipt of noninvasive ventilation (n=1047) and invasive ventilation (n=58). At baseline, the overall median partial pressure of carbon dioxide level was 58.2 mmHg.

Patients in the study received ventilation for 7.3 hours per day, and the mean time spent in home mechanical ventilation was 21.6 months. The longest duration of home mechanical ventilation was observed in the scoliosis group (46.1 months), while the shortest duration was observed in the ALS group (14.8 months).

While the score on the Severe Respiratory Insufficiency questionnaire was 47±17.9 points at baseline, scores improved significantly at 6 months (54.4±17.2 points), 12 months (57.3±17.3 points), and 36 months (57.1±18.3 points; P <.001 for all).

By August 2018, a total of 675 patients were still active in the program, but 329 had died and 101 patients had left the study. Patients in the ALS group had the lowest short-term survival at 1 year (67%) and 3 years (26%). Lowest 5-year survival rates were also reported in the COPD group (52%) and non-CF bronchiectasis and tuberculosis group (58%).

The longest 5-year survival rates were observed in the OHS (81.2%), scoliosis (77.4%), and NMD (71.4%) groups. Additionally, the longest 9-year survival rates were also observed in the OHS (57.7%), scoliosis (57.2%), and NMD (50.9%) groups.

In terms of limitations, the researchers noted that not all patients had available baseline functional data, including data on maximum inspiratory pressure, lung volumes and capacities, carbon monoxide diffusing capacity, and polygraphs. Additionally, the cohort included only adults who are beneficiaries of the Chilean public health system, suggesting the findings may not be generalizable across other populations.

Reference

Maquilón C, Antolini M, Valdés N, et al. Results of the home mechanical ventilation national program among adults in Chile between 2008 and 2017. BMC Pulm Med. 2021;21(1):394. doi:10.1186/s12890-021-01764-4