The normal physiological pH of blood is 7.35 to 7.45. An increase above this range is known to be Alkalosis. Metabolic Alkalosis is defined as a disease state where blood pH is more than 7.45 due to secondary metabolic processes. The primary pH buffers in maintaining chemical equilibrium of physiological Blood pH are alkaline Bicarbonate ions(HCO3) and acidic carbon dioxide(CO2). When there is increase amount of Bicarbonate(HCO3) in body or decrease amount of carbon dioxide or loss of hydrogen ions it causes alkalosis.  Metabolic alkalosis occurs due to trapping of Bicarbonate ions (HCO3) or loss of hydrogen ions in body due to some metabolic causes for example- gastrointestinal loss of hydrogen ions, intracellular shifting of hydrogen ions, renal hydrogen loss, increased bicarbonate ions in extracellular compartment, diuretic induced alkalosis or contraction alkalosis. Patient with normal renal physiology will compensate this increase amount of bicarbonate through excretion. But impaired renal function secondary to chloride depletion, hypokalemia, hyperaldosteronism, reduced glomerular function rate, reduced effective arterial blood volume (EABV)) in heart failure or cirrhosis will lead to metabolic alkalosis. When the physiologic blood pH is above 7.45, it triggers respiratory center to cause hypoventilation, thus decreased PCO2 leading to compensatory respiratory acidosis. The PCO2 elavates from 0.5 to 0.7 mmHg per 1.0 millimole elevation in plasma bicarbonate concentration. In severe Metabolic alkalosis PCO2 can reach 60 mmHg. The mortality rate with metabolic alkalosis is 45% with arterial blood pH 7.55 to 80% with arterial blood pH of 7.65. Supportive Treatment is usually given according to cause of the disease.
Metabolic alkalosis pathophysiology
Respiratory acidosis pathophysiology
Metabolic alkalosis risk factors
Metabolic alkalosis causes
Lactic acidosis pathophysiology
Metabolic acidosis causes
Hyperchloremia causes
Hyperkalemia pathophysiology