Respiratory assessment
Disrupted breathing patterns can occur with a variety of conditions
independent of altered neurological function (eg Kussmaul respirations
in metabolic acidosis) but changing patterns of respiration (rate, rhythm
and depth) in a neurologically vulnerable patient are important. Yawning,
hiccoughs and vomiting may be early signs indicating compression
on brainstem structures.9
Cheynes-Stokes respirations (cyclic, waxing-waning breathing pattern
with apnoea episodes) can indicate global cerebral damage or bilateral
thalamic damage.9
Neurogenic hyperventilation (deep respirations at greater than 25
breaths per minute) may be due to loss of inhibitory refl exes within
the brainstem, especially due to damage in the midbrain and pons. This
pattern of breathing should be distinguished from Kussmaul respirations
and may cause respiratory alkalosis.9,19
Apneustic breathing involves a prolonged inspiratory gasp followed by
a pause at full inhalation than release. The respiratory rate is very low
– often only two to three breaths per minute and arises as a result of
damage to the lower pons.19
Cluster breathing occurs with midbrain and pontine damage – respirations
are irregular and rapid, grouped between periods of apnoea. Ataxic
breathing (due to medullary dysfunction)involves less predictable variations
in depth and rate of breathing, combined with periods of apnoea