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Mild respiratory insufficiency tends to present with various symptoms of sleep disruption whereas later patients develop breathlessness on exertion, on lying flat and at rest. Poor cough and pneumonia should also raise suspicions.

Read more about the signs and symptoms of respiratory insufficiency and those that might warrant immediately NIV.

Regular monitor means signs and symptoms are picked up early and this can help prepare the patient and reduce delays starting NIV. Every staff member should be alert for these signs at every meeting and we’ve discussed examples of checklists that can be made.

Formal assessments using respiratory function tests and blood gases should occur a minimum of three monthly but might be more frequent if the patient is deteriorating quickly or displaying concerning signs or symptoms.

We recommend an assessment combines informational about the the signs and symptoms along with bedside tests of respiratory muscle strength and blood gas sampling. Trends over time are helpful in identifying people who are deteriorating.

The evidence suggests that testing sniff nasal inspiratory pressures is more sensitive than forced vital capacity. Peak cough flow can help assess a patient’s cough capacity. Arterial or capillary blood gases can assess bicarbonate levels which can be a sensitive indicator to nocturnal problems.

What tests are used in a service might depend on practicalities such as available equipment, infection control requirements or whether a patient can attend hospital. We discuss where testing is limited and staff should be aware of situations where tests can be inaccurate or falsely reassuring.

The key to respiratory assessment is to identify the need for NIV early enough to allow patients to be prepared to start NIV. We identified delays in this pathway which include delays in referring patients to respiratory service or not commencing respiratory testing early enough.

Good communication between staff, patients and their carers about respiratory function helped monitor signs and symptoms and prepare patients. In most cases the need to start NIV urgently can be avoided by regular monitoring but when this occurs the service should be able to initiate NIV immediately.

We describe situations where patients may not recognise symptoms of respiratory insufficiency or where testing may be inaccurate. This includes patients with bulbar dysfunction and those with cognitive impairment. This section discusses some strategies to help with these challenges.