Hypoxia is a decrease in the influx of oxygen to the tissues to below the physiological level even though blood tissue perfusion is adequate.
Hypoxia can occur due to oxygen deficiency at the tissue level consequently the cells do not get enough oxygen so that cell metabolism will be disrupted. Hypoxia can be caused by:
The First Cause
Insufficient lung oxygenation due to extrinsic circumstances, either due to lack of oxygen in the atmosphere or due to hypoventilation (muscle nerve disorders).
Lung disease, hypoventilation due to increased respiratory arrest or pulmonary compliance decreased. The ventilation -perfusion ratio is not the same. Decreased membrane of respiratory diffusion
The Third Cause
Shunt vein to artery (shunt from "right to left 'on network)
Inadequate transport and release of oxygen (inadekuat). This occurs in anemia, decreased general circulation, decreased local circulation (peripheral, cerebral, cardiac vascular), tissue edema
The Fifth Cause
Insufficient oxygen utilization in the tissues, eg in cellular deficiency due to vitamin B deficiency
Hypoxia can be caused by cardiovascular failure such as shock, abnormal hemoglobin, cardiovascular disease, alveolar hypoventilation, shunt lesions, diffusion problems, ventilation-perfusion abnormalities, chemical effects eg carbon monoxide, altitude, local tissue factors eg increased metabolic demand, effects on tissue metabolism which further lead to tissue acidosis and result in effects on vital signs and effects on the level of consciousness.
In anesthesia, respiratory failure may be caused by surgery itself, for example because of a muscle relaxant drug, due to vomiting or mucus, a disease (coma, stroke, brain inflammation), trauma / accident (maxillofacial trauma, head trauma, poisoning) .