Some science behind the scenes

Brain and organ damage from hypoxia

When the brain is starved of oxygen it becomes low in energy and initially resorts to using anaerobic respiration within the region of brain tissue affected. Unfortunately, this kind of respiration releases lactic acid. Lactic acid is an irritant which destroys cells since it disrupts the normal acid-base balance in the brain.

As the oxygen or glucose becomes further or totally depleted the production of adenosine triphosphate (ATP) fails, leading to failure of energy-dependent processes (such as ion pumping) necessary for tissue cell survival. This sets off a series of interrelated events that result in further cellular injury and death.

A major cause of neuronal injury is release of the excitatory neurotransmitter glutamate. The concentration of glutamate outside the cells of the nervous system is normally kept low by so-called uptake carriers. However, if the supply of oxygen and glucose which powers the ion pumps maintaining these gradients is cut off, glutamate transporters reverse their direction, releasing glutamate into the extracellular space. Glutamate acts on receptors in nerve cells (especially NMDA receptors), producing an influx of calcium which activates enzymes that digest the cells' proteins, lipids and nuclear material.

You may also suffer organ damage.  Depriving any organ of oxygen can damage it, for example, it can cause blindness………….

Cortical blindness following hypoxia during cardiac arrest - Kam CA, Yoong FF, Ganendran A.
Two patients with cortical blindness following hypoxic episodes are reported. The characteristics of the syndrome are described. Attention is drawn to the lack of awareness of this complication of hypoxia.

PMID: 665992

It can damage the heart…………………

Pathophysiology and clinical effects of chronic hypoxia - Pierson DJ.; Department of Medicine, University of Washington, Seattle, USA.
Hypoxia exists when there is a reduced amount of oxygen in the tissues of the body. Hypoxemia refers to a reduction in PO2 below the normal range, regardless of whether gas exchange is impaired in the lung, CaO2 is adequate, or tissue hypoxia exists. ………….. Chronic alveolar hypoxia is the main factor leading to development of cor pulmonale--right ventricular hypertrophy with or without overt right ventricular failure—

 PMID: 10771781

Cor pulmonale or pulmonary heart disease is enlargement of the right ventricle of the heart as a response to increased resistance or high blood pressure in the lungs.

It can damage your liver………………

Hypoxia and hypoxia inducible factors: diverse roles in liver diseases - Nath B, Szabo G.; Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA.
Hypoxia has been shown to have a role in the pathogenesis of several forms of liver disease. The hypoxia inducible factors (HIFs) are a family of evolutionarily conserved transcriptional regulators that affect a homeostatic response to low oxygen tension and have been identified as key mediators of angiogenesis, inflammation, and metabolism. In this review we summarize the evidence for a role of HIFs across a range of hepatic pathophysiology. We describe regulation of the HIFs and review investigations that demonstrate a role for HIFs in the development of liver fibrosis, activation of innate immune pathways, hepatocellular carcinoma, as well as other liver diseases in both human disease as well as murine models.

PMID:  22120903

It can damage your kidneys………………..

Hypoxia and the HIF system in kidney disease - Nangaku M, Eckardt KU. ;  Division of Nephrology and Endocrinology, University of Tokyo School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
The kidney is sensitive to changes in oxygen delivery. This sensitivity has the merit of facilitating the kidneys in their adjustment of erythropoietin (EPO) production to changes in oxygen supply. ……….. However, the high sensitivity to changes in oxygen tension also makes the kidney prone to hypoxic injury. Severe energy depletion and subsequent activation of a number of critical alterations in metabolism occurs under hypoxic conditions. Hypoxia is also a profibrogenic stimulus. In addition to ischemic acute renal failure, hypoxia can also play a crucial role in the development of nephrotoxic acute kidney injury, radiocontrast nephropathy, and acute glomerulonephritis. Furthermore, accumulating evidence suggests that chronic hypoxia is a final common pathway to end-stage kidney failure in chronic kidney disease. ….