Acid-base Imbalance

An acid-base imbalance occurs when the body fails to maintain the narrow balance between acids and bases. This imbalance can impair essential metabolic processes like functioning of enzymes, oxygen transport, and removal of waste products.

Okay, so, the measurement of acids and bases is called the pH. On the pH scale, 7.0 is considered neutral; levels above 7.0 are alkalotic, or basic; and levels below 7.0 are acidotic. The normal range for pH in the blood for adults is 7.35 to 7.45.

The main molecules involved in acid-base balance are hydrogen bicarbonate, Partial pressure of carbon dioxide, and partial pressure of oxygen. hydrogen has an inverse relationship with the pH of body fluids. So, when there’s more hydrogen, the pH decreases and becomes more acidic; whereas when there’s less hydrogen, the pH increases.

Next, bicarbonate is a basic substance; so, when there’s more bicarbonate the pH increases, and body fluids become more alkalotic. Likewise, when there’s less bicarbonate the pH decreases, and body fluids become more acidotic.

Then there’s partial pressure of carbon dioxide which reflects the amount of acidic carbon dioxide dissolved in the arterial blood; and partial pressure of oxygen which reflects the amount of oxygen dissolved in the arterial blood.

Now, acid-base balance is regulated by various mechanisms in the body.

The cellular buffering system, located in the extra- and intracellular fluid compartments, is able to rapidly absorb excessive acidic and basic ions to minimize pH fluctuations.

Also, the respiratory system controls pH through adjusting carbon dioxide amounts by changing the rate and depth of breathing; and the renal system manages the amount of excreted and reabsorbed bicarbonate by the kidneys.

Alright, now, acid-base imbalances occur when the pH is outside the normal range.

These imbalances are categorized as either acidotic or alkalotic, depending on the pH level, and metabolic or respiratory, depending on the cause of the imbalance. The four primary types of acid-base imbalance are metabolic acidosis, respiratory acidosis, metabolic alkalosis, and respiratory alkalosis.

Starting with metabolic acidosis, this generally refers to a build-up of acid, which can happen due to conditions like diabetic ketoacidosis, or DKA, where the breakdown of fatty acids from hyperglycemia leads to increased acid production.

It can also happen when too much acid is ingested through substances like salicylates, such as aspirin, or ethylene glycol which is used in automotive antifreeze solutions.

It can also occur when the body is unable to excrete acids, as seen in kidney disease; or from bicarbonate loss from the GI tract, like with excessive diarrhea. Now, to compensate, the respiratory system will increase respirations to blow off extra carbon dioxide and begin to eliminate the extra acid.

Next is respiratory acidosis, which occurs when the lungs can’t eliminate excess carbon dioxide.