Acid-base balance refers to the mechanisms in the body uses to keep its fluids close to normal pH (that is, neither basic nor acidic) so that the body can function normally. Arterial blood pH is normally : between 7.35 and 7.45 What is acid base balance
Why is acid-base balance important? Because any disturbance in ph range effect on multi system and process in body as : Enzyme systems, oxygenation, muscle, nerve and metabolic functions of the body work best within a specific pH range.
Definition of acid-base disorders a change in the normal value of extracellular pH An acid base disorder is a change in the normal value of extracellular pH that may result when renal or respiratory function is abnormal or when an acid or base load overwhelms excretion capacity.
Some Causes of acid base disturbance (generally) Dm (m a) Shock ( septic,hypovolemic,cardognic) (m a) Renal failure (m a) Vomiting (m al) Diuretics (m al) Asthma (r al) Hyperventilation syndrome (r al) Copd (r a) Myasthenia gravis (r a)
Response to acid – base disturbance: H ＋ load ECFlungICFRenalBone Buffers Mainly Hco 3 co 2 Respiratory control Cellular Hpo 4 (weak) H + excretion bicarbonate reabsorption Release bone salt H ＋ － K ＋ exchange Ca 2 ＋ ＋ H 2 PO 4 In chronic metabolic acidosis H 2 CO 3 CO 2 Acid excretion Hyperventilation hyopventilation Immediately minutes hoursdays Very slow