Diaphragm dysfunction: a comprehensive review from diagnosis to management

Although the diaphragm represents a critical component of the respiratory pump, the clinical presentations of diaphragm dysfunction are often non-specific and can be mistaken for other more common causes of dyspnoea. While acute bilateral diaphragm dysfunction typically presents dramatically, progressive diaphragm dysfunction associated with neuromuscular disorders and unilateral hemidiaphragm dysfunction may be identified incidentally or by recognising subtle associated symptoms. Diaphragm dysfunction should be considered in individuals with unexplained dyspnoea, restrictive respiratory function tests or abnormal diaphragm position on plain chest imaging. A higher index of suspicion should occur for individuals with profound orthopnoea, those who have undergone procedures in proximity to the phrenic nerve(s) or those with co-morbid conditions that are associated with diaphragm dysfunction, particularly neuromuscular disorders. A systematic approach to the evaluation of diaphragm function using non-invasive diagnostic techniques such as respiratory function testing and diaphragm imaging can often confirm a diagnosis. Neurophysiological assessment may confirm diaphragm dysfunction and assist in identifying an underlying cause. Identifying those with or at risk of respiratory failure can allow institution of respiratory support, while specific cases may also benefit from surgical plication or phrenic nerve pacing techniques.