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.

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.

Pilot Study of Two Nurse-Led Weaning Protocols in Patients with Tracheostomies

This is a pilot study, comparing two commonly-used weaning techniques in patients with a tracheostomy to establish if one technique resulted in shorter time to successful weaning. In a prospective, single-centre randomised, controlled trial, conducted in a 15-bed multidisciplinary intensive care unit, fifty patients mechanically ventilated for at least 48 hours and who had a tracheostomy inserted primarily for weaning purposes, were randomised to one of two weaning techniques: increasing periods of spontaneous ventilation, or reducing pressure support ventilation. Each technique was protocolised for implementation by the nursing staff and consisted of two stages: a weaning and a verification stage. This pilot study did not find a statistically significant difference in the length of time spent weaning when two nurse-led protocolised weaning techniques of increasing periods of spontaneous ventilation or reducing pressure support ventilation were compared in patients with a tracheostomy inserted primarily for weaning purposes. No safety issues were identified in either protocol.

The Nottingham Head Injury Register: A Survey of 1,276 Adult Cases of Moderate and Severe Traumatic Brain Injury in a British Neurosurgery Centre

The Nottingham Head Injury Register was established as an audit and research tool for traumatic brain injury (TBI). Study aims included examination of the epidemiology of UK TBI and identification of factors improving management and outcome. Moderate and severe TBI patients admitted to a UK neurosurgery centre were recruited over a 10-year period from 1993 to 2003. A dataset covering all aspects of TBI, including demography, clinical features, investigations, management, complications and outcome were captured prospectively into a computerised database. The study group comprised 1,276 adult patients aged more than 16 years old. The median age of subjects was 35 years, with 78% of the population consisting of male patients. Road traffic accidents were responsible for 49% of injuries; 37% of the study population had moderate TBI and 63% severe TBI. CT brain scan was performed in 92% of cases showing a mass lesion in 41% and diffuse lesion in 59%. Traumatic subarachnoid haemorrhage was present in 34%. At 12 months 32% of patients had died, 13% were severely disabled, 22% were moderately disabled and 33% had made a good recovery. Findings were comparable with other previous large series of TBI patients from international studies. Registry data is useful to define TBI epidemiology and management, and in validation of prognostic scoring systems.