Long-term adherence to home mechanical ventilation: a 10-year retrospective, single-centre cohort study.

BACKGROUND: Sleep-disordered breathing (SBD) can be associated with hypercapnic respiratory failure (HRF). Home Mechanical Ventilation (HMV) is the preferred long-term treatment for patients with chronic HRF. We reviewed the database of a large tertiary referral centre for HMV to study the long-term adherence to HMV in chronic hypercapnic patients. METHODS: Data on adherence and characteristics of patients who received HMV for the treatment of SDB were collected over a decade using electronic patient records. The primary outcome parameter in this study was annual non-adherence rate (patients with HMV usage of <4 hours/night in the service divided by the number of all new patients of the same year), secondary outcomes were patients' characteristics and reasons for low adherence. HMV adherence clinics were established to improve uptake. RESULTS: Two thousand and two hundred twenty-eight patients with HRF were under active follow-up on HMV at the end of the recording period. In contrast, a total of 1,900 patients had their HMV contracts terminated over the course of a decade (due to non-adherence, transfer to other services or death). Out of those, 222 patients {62 [52-72] years, body-mass index, BMI 40 [35-43] kg/m2, 58.1% male, Epworth Sleepiness Scale, ESS 9 [4-15] points, 4% oxygen desaturation index, 4%ODI 32 [20-71] × hour-1, TcCO2 6.6 [6.0-7.2] kPa} met the non-adherence criteria (nocturnal usage 0-4 hours). The annual non-adherence rate was 25.5% of all new setups in 2010, and declined to 3.4% in 2019 (relative reduction of 86%, P<0.001). Patients with Obstructive Sleep Apnoea/Obesity Hypoventilation Syndrome (58.2%), Neuromuscular Diseases (NMD) (26.8%) and COPD (13.6%) accounted for most cases of this non-adherent cohort. The vast majority of the patients (96.1%) were established on full-face masks. In 23.4% of patients, substantial weight loss (>10%) was the most common reason for low adherence; general displeasure (21.3%), uncontrolled symptoms (12.8%), claustrophobia (6.7%), mood (4.8%) and mask intolerance (4.3%) caused problems as well. CONCLUSIONS: Non-adherence to HMV in patients with chronic HRF can affect significant proportions of patients. However, the non-adherent rate substantially decreases when individual treatment solutions are offered in multi-disciplinary clinics.

Time-to-death in chronic respiratory failure on home mechanical ventilation: A cohort study.

BACKGROUND AND OBJECTIVE: Home mechanical ventilation (HMV) is used in heterogeneous conditions underlying chronic hypercapnic respiratory failure, but there are sparse data on long-term clinical outcomes. The aim was to systematically analyse the time and the circumstances of death on HMV. METHODS: All-cause mortality data of HMV patients were prospectively collected between 2008 and 2018 in a large tertiary centre. Data were categorised into diagnostic groups including neuromuscular disease (NMD), chest wall disease (CWD), chronic obstructive pulmonary disease (COPD), obesity hypoventilation syndrome (OHS), overlap syndrome of COPD and OSA (overlap) and other group. The primary outcome was time-to-death from initiation of HMV. RESULTS: 1210 deaths were recorded over a 10-year period. Median time-to-death was 19.5 [6-55] months and differed between groups (Kruskal Wallis p < 0.001). CWD (98.5 [23.5-120] months) and slowly progressive NMD (64.5 [28-120] months) had the longest time-to-death on HMV, while OHS (33 [13-75] months) and overlap syndrome (30.5 [14.5-68.5] months) had a longer median time-to-death than COPD (19.5 [7-42.5] months) and motor neurone disease (7 [3-14] months). Daily adherence to HMV of greater than 4 h/night was associated with better outcomes (10 [3-24] vs. 30 [10-76] months; p < 0.001). 43% with confirmed location of death died outside the hospital. CONCLUSIONS: The time-to-death on home mechanical ventilation varies widely across disease groups with chronic respiratory failure and seems to be associated with daily usage time. TRIAL REGISTRATION: researchregistry.com UIN: researchregistry4122.

Prospective observational cohort study of patients with weaning failure admitted to a specialist weaning, rehabilitation and home mechanical ventilation centre.

OBJECTIVES: According to National Health Service England (NHSE) specialist respiratory commissioning specification for complex home ventilation, patients with weaning failure should be referred to a specialist centre. However, there are limited data reporting the clinical outcomes from such centres. SETTING: Prospective observational cohort study of patients admitted to a UK specialist weaning, rehabilitation and home mechanical ventilation centre between February 2005 and July 2013. PARTICIPANTS: 262 patients admitted with a median age of 64.2 years (IQR 52.6-73.2 years). 59.9% were male. RESULTS: 39.7% of patients had neuromuscular and/or chest wall disease, 21% were postsurgical, 19.5% had chronic obstructive pulmonary disease (COPD), 5.3% had obesity-related respiratory failure and 14.5% had other diagnoses. 64.1% of patients were successfully weaned, with 38.2% weaned fully from ventilation, 24% weaned to nocturnal non-invasive ventilation (NIV), 1.9% weaned to nocturnal NIV with intermittent NIV during the daytime. 21.4% of patients were discharged on long-term tracheostomy ventilation. The obesity-related respiratory failure group were most likely to wean (relative risk (RR) for weaning success=1.48, 95% CI 1.35 to 1.77; p<0.001), but otherwise weaning success rates did not significantly vary by diagnostic group. The median time-to-wean was 19 days (IQR 9-33) and the median duration of stay was 31 days (IQR 16-50), with no difference observed between the groups. Weaning centre mortality was 14.5%, highest in the COPD group (RR=2.15, 95% CI 1.19 to 3.91, p=0.012) and lowest in the neuromuscular and/or chest wall disease group (RR=0.34, 95% CI 0.16 to 0.75, p=0.007). Of all patients discharged alive, survival was 71.7% at 6 months and 61.8% at 12 months postdischarge. CONCLUSIONS: Following NHSE guidance, patients with weaning delay and failure should be considered for transfer to a specialist centre where available, which can demonstrate favourable short-term and long-term clinical outcomes.

Validation of the IMPACT outcome prediction score using the Nottingham Head Injury Register dataset.

BACKGROUND: Comparison of traumatic brain injury (TBI) outcomes is severely limited by the absence of a universally accepted and validated outcome prediction score. The IMPACT group recently reported models predicting mortality and unfavorable outcome after TBI, based on the outcomes of patients with moderate and severe head injury reported in two large clinical trials. METHODS: We have used prospectively collected data from 1,276 adult patients from the Nottingham Head Injury Register admitted to a single UK neurosurgical unit during a 10-year period to validate the IMPACT score models. The two models were validated for discrimination, calibration, and accuracy, using multiple imputation to adjust for missing data. RESULTS: One thousand sixty-one patients (83%) had a complete set of data. For the multiply imputed analysis, the IMPACT prognostic models showed satisfactory discrimination (area under the receiver operator curve for mortality, 0.835; 95% confidence interval, 0.811-0.858; unfavorable outcome, 0.828; 95% confidence interval, 0.805-0.851) and accuracy (Brier Accuracy Score for mortality, 0.403, p < 0.01; unfavorable outcome, 0.371, p < 0.01). Good calibration was evident for unfavorable outcome, but mortality risk was underestimated by the scoring system in our sample (Hosmer-Lemeshow test: mortality: p < 0.01; unfavorable outcome: p = 0.6). These results were not significantly changed when repeated using patients with complete data only. CONCLUSION: The 2005 IMPACT model for unfavorable outcome performs well when used to predict outcome in adults with moderate and severe TBI presenting to a British neurosurgical center. However, the model for mortality fitted less well, slightly overestimating mortality in the higher-risk groups.