What is Apneustic Breathing
Apneustic breathing is an abnormal respiratory pattern characterized by prolonged inspiratory gasps with an inability to fully expire, resulting from damage to the pneumotaxic center in the pons. 1
Pathophysiology and Mechanism
The respiratory abnormality occurs due to disruption of the pontine respiratory control centers, specifically affecting the mechanisms that normally terminate inspiration. 1, 2 The condition results from:
- Depression of glutamatergic synaptic processes that are necessary for activating inhibitory mechanisms to end inspiration 2
- Damage to the pneumotaxic center in the pons, which is the core respiratory control center in the brainstem 1
- Impaired synaptic transmission leading to prolonged inspiratory efforts and apneustic discharges of brainstem respiratory neurons 2
Clinical Presentation
The characteristic features include:
- Severely prolonged inspiratory effort with gasping respirations 1, 2
- Inability to fully expire, creating a distinctive breathing pattern 1
- Loss of gag reflex and other cranial nerve deficits frequently accompany the respiratory changes 1
- Patients may remain alert and conscious despite the abnormal breathing pattern 3
Common Etiologies
Apneustic breathing typically occurs after:
- Pontine infarction or trauma affecting the brainstem respiratory centers 1, 4, 5
- Overdose of central nervous system depressants 2
- Asphyxia, hypoxia, or ischemia affecting the lower brainstem and pons 2
- Neurosurgical procedures involving the pons and medulla oblongata 2
- Blockade of glutamate receptors 2
Critical Pitfalls
Do not confuse apneustic breathing with other abnormal respiratory patterns such as Cheyne-Stokes breathing, which involves a crescendo-decrescendo pattern between central apneas. 6 Apneustic breathing is characterized by prolonged inspiratory holds, not periodic cycling of ventilation.
The condition is commonly encountered in neurological intensive care units following pontine trauma and requires immediate recognition for appropriate airway management. 1
Treatment Considerations
Serotonin 1A receptor agonists (such as buspirone) have shown effectiveness in converting apneustic patterns to normal breathing by facilitating the inhibitory mechanisms that terminate inspiration. 2, 4 Oral buspirone administration has produced prompt and effective remission of apneusis without side effects in documented cases. 2