Acid Base Balance And Fluids And Electrolytes Essay

918 Words Nov 9th, 2015 4 Pages
Acid-Base Balance and Fluids and Electrolytes Respiratory acidosis is an abnormally high PCO2 in systemic arterial blood—above 45 mmHg. Inadequate exhalation of CO2 causes the blood pH to drop. Any result that reduces the activity of CO2 from the blood to the alveoli of the lungs to the atmosphere causes an escalation of CO2, H2CO3, and H+. Such conditions include emphysema, pulmonary edema, injury to the respiratory center of the medulla oblongata, airway obstruction, or disorders of the muscles involved in breathing. If the respiratory problem is not too serious, the kidneys can help promote the blood pH into the normal range by increasing excretion of H+ and reabsorption of HCO3− (renal compensation). For respiratory alkalosis, systemic arterial blood PCO2 falls below 35 mmHg. The cause of the drop in PCO2 and the resulting increase in pH is hyperventilation, which occurs in conditions that stimulate the dorsal respiratory group in the brain stem. Such conditions include oxygen deficiency due to high altitude or pulmonary disease, cerebrovascular accident (stroke), or severe anxiety. Again, renal compensation may bring blood pH into the normal range if the kidneys are able to decrease excretion of H+ and reabsorption of HCO3−. In metabolic acidosis, the systemic arterial blood HCO3− level drops below 22 mEq/liter. Such a decline in this important buffer causes the blood pH to decrease. "Three situations may lower the blood level of HCO3−: (1) actual loss of HCO3−, such…

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