Following are the Hypoxia signs
- Psychological Hypoxia signs – Higher centers are first impaired in hypoxia due to deficiency of oxygen to the brain tissue.
Psychomotor and emotional judgement is poor in the absence of oxygen.
The mechanisms mediating cerebral vasodilation during hypoxia are not fully understood but may include neurogenic effects initiated by peripheral and neuraxial chemoreceptors, as well as local humoral influences. At least part of the hyperemic response to hypoxia is mediated by NO of neuronal origin .
Hypoxia-induced hyperpolarization of vascular smooth muscle by the opening of ATP-dependent K+ channels also leads to vasodilation. Recent studies have indicated that the rostral ventrolateral medulla (RVM) serves as an oxygen sensor within the brain.
Stimulation of the RVM by hypoxia results in an increase in CBF (but not CMR), and lesions of the RVM suppress the magnitude of the CBF response to hypoxia. The response to hypoxia is synergistic with the hyperemia produced by hypercapnia and acidosis. At high Pao2 values, CBF decreases modestly. At 1 atm of oxygen, CBF is reduced by 12%.
- Hypoxia signs on Sensory system – Headache, Malaise, lassitude, precordial pain
- Gastrointestinal system – Nausea, retching and vomiting
- Muscular Hypoxia signs - In coordination – Flaccidity