The physiological effects of high altitude
| Acute effect | Found in indigenous | |
|---|---|---|
| Comparisons are related to sea level values: → no difference; ↑ increased; ↓ reduced. | ||
| Data relates to children where it exists (see text) | ||
| *May be accounted for by factors such as socioeconomic deprivation. | ||
| Respiratory | ||
| Arterial pO2 and oxygen saturation | ↓ | ↓ |
| Minute ventilation | ↑ | ↑ |
| Carbon dioxide | ↓ | ↓ |
| Oxygen consumption/CO2 production | ↓ | → |
| Lung volumes (vital capacity, residual volume) | ↑ | ↑ |
| Lung compliance | ↑ | |
| Peak flow/forced expiratory volume in 1s | ↓ | |
| Lung gas transfer (DLCO) | ↓ | ↑ |
| Nocturnal arousals/less active sleep | ↑ | |
| Periodic breathing | ↑ | |
| Cardiovascular | ||
| Heart rate | ↑ | → |
| Cardiac output | ↑ | → |
| Pulmonary artery pressure | ↑ | ↑ |
| Pulmonary vascular resistance | ↑ | |
| Capillary leak | ↑ | |
| Erythropoietin and red blood cell production | ↑ | ↑ |
| Neurological | ||
| Cerebral blood flow | ↑ | |
| Intracranial pressure | ↑ | |
| Body growth | ||
| Birth weight | ↓ | |
| Postnatal growth | ↓* | |