The RSSC provides specialist treatments to people with respiratory failure due to a wide range of conditions. Patients are assessed for their suitability for treatment and long-term follow-up is arranged for those started on ventilatory support. The RSSC currently cares for over 1,300 patients on ventilatory support in their own homes. When indicated, assisted ventilation is generally only required overnight, although some patients may also require ventilation in the day as well.
Conditions in which benefit from home ventilation may be achieved include:
- Chest wall disorders (such as scoliosis, thoracoplasty and obesity-hypoventilation syndrome)
- Neuromuscular disorders (such as muscular dystrophies, myotonic dystrophy, motor neurone disease and diaphragmatic dysfunction)
- Neurological disorders (such as spinal cord injuries and central alveolar hypoventilation)
- Pulmonary diseases (such as COPD, bronchiectasis and cystic fibrosis)
Chest wall disorders and obesity-hypoventilation
If lung function is sufficiently impaired, patients with stable chest wall disease, such as scoliosis or thoracoplasty, may develop respiratory failure. The use of nocturnal home ventilation in these circumstances is well-established and provides considerable improvements in morbidity and mortality. More recently, evidence of benefit has also been demonstrated for patients with obesity-hypoventilation syndrome.
Who to refer?
- Symptomatic patients (dyspnoea, orthopnoea, early morning headaches, daytime fatigue or sleepiness)
- PaCO2 > 6 kPa.
Neuromuscular disorders
In progressive neuromuscular diseases, assisted ventilation aims to reduce respiratory symptoms and improve quality of life. In so doing, a significant prolongation of life has been demonstrated, for example in patients with Duchenne Muscular Dystrophy and Motor Neurone Disease.
Duchenne Muscular Dystrophy
Duchenne Muscular Dystrophy (DMD) patients generally lose the ability to walk by the age of 12 years and weakness progresses to involve respiratory muscles over the next few years towards adulthood. Without assisted ventilation, the average survival is to 19 years and the predominant cause of death is respiratory failure. The use of home ventilation increases survival substantially and, importantly, quality of life has been shown to be well-preserved, even in ventilator-dependent patients.
Who to refer?
It is preferable for referral to take place for ventilatory assessment prior to the onset of significant respiratory symptoms. This enables the accurate monitoring in any decline in ventilatory status and ensures optimal timing for the institution of assisted ventilation.
Motor Neurone Disease
At first presentation, most patients with MND have no respiratory symptoms, but the large majority have abnormal respiratory function. The development of symptoms of respiratory muscle weakness, or an increase in daytime PaCO2 > 6 kPa, often heralds a rapid decompensation in ventilatory function and is associated with an extremely poor prognosis without assisted ventilation. Non-invasive ventilation, for appropriate patients, prolongs life and improves quality of life without adversely affecting carers.
Key components of the MND Service include:
- A multi-disciplinary approach, in conjunction with the regional MND coordinators
- The provision of domiciliary non-invasive ventilation
- Airway clearance techniques and interventions
- Enteral feeding
Who to refer?
We are happy to assess any patient with MND. Patients with orthopnoea, morning headaches, progressive dyspnoea, or a PaCO2 > 6 kPa should be referred urgently for respiratory review.
Neurological Disorders
To function effectively, the respiratory system requires adequate central control. A wide range of neurological conditions can result in ventilatory impairment, for example spinal cord injuries and Central Alveolar Hypoventilation.
Who to refer?
Symptomatic patients (dyspnoea, orthopnoea, early morning headaches, daytime fatigue or sleepiness)
- PaCO2 > 6 kPa.
Pulmonary Disorders
Although patients with pulmonary disease represent a common cause of chronic ventilatory failure, the role of home ventilation has yet to be fully established. It has been introduced successfully in patients with Chronic Obstructive Pulmonary Disease (COPD), bronchiectasis and cystic fibrosis.
Who to refer?
Home ventilation should be considered in stable COPD patients with:
- Symptomatic hypercapnia
- Hypercapnia and intolerance of long-term oxygen therapy
- Recurrent exacerbations complicated by hypercapnia
Case study
Mrs SL (aged 78) was diagnosed with COPD 8 years previously. She had stopped smoking 12 years ago but had a 40-year smoking history. She had approximately two exacerbations per year but had not required hospital admission until the preceding 9 months. When admitted, she was hypercapnic (PaCO2 7.2 kPa), but improved with controlled oxygen therapy, steroids, nebulisers and antibiotics. Although she made an uncomplicated recovery, she never quite returned to her previous level and her lung function confirmed severe COPD. She needed a number of courses of steroids and antibiotics in the community.
When readmitted as an emergency 6 months later, she briefly received treatment with non-invasive ventilation acutely as she had developed acute-on-chronic respiratory failure. Although successfully discharged from hospital with long-term oxygen therapy and closely supported by her community respiratory specialist nurse, she was rarely well enough to leave her house. When readmitted to hospital with a further exacerbation, she required further acute treatment with non-invasive ventilation.
She was referred to the RSSC for ventilatory assessment and was transferred as an inpatient. Arterial blood gases confirmed persistent respiratory failure (PaO2 6.7, PaCO2 7.9, self-ventilating on air) and her sleep study demonstrated nocturnal hypoventilation. She was commenced on non-invasive ventilation and took to this well. Over the course of the next 3 nights, her ventilator settings were optimised. Arterial blood gases on discharge home improved to PaO2 7.6, PaCO2 6.5 self-ventilating on air. At review 6 weeks later, she had been using her non-invasive ventilation every night and reported significant overall improvement. Her exercise tolerance had improved such that she was able to get back to gardening. Her arterial blood gases now demonstrated PaO2 8.6, PaCO2 6.3 on air and her overnight sleep study on non-invasive ventilation showed no evidence of hypoventilation.
Specialist oxygen provision
The RSSC provides a comprehensive assessment for all types of oxygen treatment, including long-term oxygen therapy, ambulatory oxygen assessments (particularly portable systems for use outside the home), and when oxygen is required in conjunction with home ventilatory support. In addition, the RSSC has developed expertise in new methods of oxygen delivery, such as transtracheal catheters.
The Progressive Care Programme (invasive weaning mechanical ventilation programme)
The RSSC provides a specialist weaning service for patients who have remained ventilator-dependent at other hospitals. This Progressive Care Programme aims to wean patients as far as possible from invasive mechanical ventilation.
Since its introduction in 1992, more than 600 patients have been referred from other centres throughout the United Kingdom. A recent audit has confirmed that more than 80% have survived to leave hospital and more than 70% have returned to an independent life in the community. The outcome of patients referred to the Progressive Care Programme compares favourably to published data from other centres, in which the in-hospital mortality of patients requiring prolonged mechanical ventilation ranges from 43-61%.
These improvements in outcome are achieved through a multi-disciplinary team approach. Following optimisation of their medical condition, non-invasive ventilation is often used to allow a graded withdrawal of invasive support. The RSSC has a unique combination of expertise in this area, including tracheostomy management, non-invasive ventilation, optimisation of airway clearance, rehabilitation and discharge planning.
The service has been cited as a model for the future provision of Critical Care step down programmes and has been demonstrated to be cost-effective compared to the cost of ongoing ventilation within a Critical Care environment.
Who to refer?
We are happy to receive referrals on any patient who is failing to wean from mechanical ventilation. Transfer to the RSSC may take place once the patient is felt to be medically stable and is free from other organ support. We would recommend early liaison with the RSSC, particularly if longer-term non-invasive ventilation might be anticipated, for example in those with neuromuscular disorders.
Case study
55-year old Mr RF was admitted as an emergency to his local hospital with rapidly worsening breathlessness. Prior to admission, he had developed a cough productive of purulent sputum. In addition, he had been aware of mild exercise limitation for the preceding three months associated with some weakness of his left hand. Clinical examination and investigations were consistent with a severe community-acquired pneumonia. He required intubation and ventilation within 24 hours of hospital admission. Over the following week, he needed inotropic support for a few days but gradually improved. However, he was generally weak and did not improve sufficiently to be extubated. A tracheostomy was undertaken to facilitate ventilatory weaning. Neurological assessment was consistent with Motor Neurone Disease and he failed to make further progress despite clearance of his pneumonia.
He was referred to the RSSC Progressive Care Programme (invasive weaning mechanical ventilation programme) service to assist further weaning. On transfer, he was continuously ventilated via tracheostomy. Ventilation was continued overnight and attempts at spontaneous breathing were attempted during the day once arterial blood gases had been normalized. His tracheostomy was downsized and he tolerated non-invasive ventilation for progressively longer periods. Sputum clearance was initially a significant problem but improved with intensive physiotherapy and he was eventually decannulated. After two weeks, he continued to require non-invasive ventilation at night but became independent of ventilatory support during the day. He was discharged home after three and a half weeks.