Transcript for:
Understanding Acid-Base Disorders

welcome back to learn with Med nuggets in this video we will be talking about metabolic and respiratory acidosis and alkalosis even a slight variance outside of normal pH can be life-threatening so our kidneys and lungs work together to correct slight pH imbalances that occur in the body the kidneys compensate for shortcomings of the lungs and the lungs compensate for shortcomings of the kidneys pH refers to the concentration of hydrogen ions in the blood the normal pH of blood is between 7.35 and 7.45 a blood pH of less than 7.35 is considered acidic while a blood pH of more than 7.45 is considered alkaline the lungs correct the blood pH by regulating the partial pressure of carbon dioxide level in the blood while the kidneys correct blood pH by regulating the bicarbonate level in the blood usually respiratory compensation happens faster it may start within minutes whereas renal compensation may take days the lungs regulate paco2 by changing the rate or depth of respirations a decrease in the respiratory rate or depth can lead to carbon dioxide retention as you breathe out less carbon dioxide the retention of carbon dioxide is called respiratory acidosis this is because carbon dioxide reacts with water to produce hydrogen ions which reduces the pH similarly an increase in the rate or depth of respirations can remove additional carbon dioxide decreasing the hydrogen ion concentration in the blood this is called respiratory alkalosis now let's look at some conditions that can increase the respiratory rate and decrease the respiratory rate an increase in the respiratory rate can increase the pH causing respiratory alkalosis this can be caused by any condition that increases the firing of the respiratory sentence centers in the brain like panic attacks pulmonary embolism in pulmonary embolism sudden pulmonary vascular obstruction results in a sudden drop in the partial pressure of oxygen which can be compensated by taking deeper or rapid breaths high altitude the low oxygen concentration can stimulate the respiratory Center to breathe in more oxygen drug overdoses like salicylates during the early phase can increase the respiratory rate respiratory alkalosis may be compensated by metabolic acidosis a reduction in respiratory rate can lead to respiratory acidosis this can be caused by Airway obstruction by a foreign object acute and chronic lung diseases drugs that directly inhibit the respiratory center of the brain like sedatives and opioids Strokes and dysfunction of the diaphragm or chest wall muscles which can be caused by trauma and obesity respiratory acidosis may be compensated by metabolic alkalosis our kidneys regulate the blood pH level by altering the concentration of bicarbonate ions in the blood if the pH becomes too acidic the kidneys absorb bicarbonate similarly if the pH becomes too alkaline the kidneys excrete more bicarbonate to bring the PH down to normal this can lead to metabolic acidosis or alkalosis metabolic acidosis can happen due to the buildup of hydrogen ions in the blood or the removal of bicarbonate ions from the blood a buildup of hydrogen ions can happen during ingestion of substances like ethylene glycol also known as antifreeze iron and ice and I said it can also happen during diabetic ketoacidosis and in conditions like CKD where the scarred kidneys are unable to function properly to excrete hydrogen ions removal of bicarbonate from blood can happen during severe diarrhea as intestinal secretions are rich in bicarbonate ions Addison's disease due to insufficient production of aldosterone by the adrenal glands aldosterone is a hormone that increases sodium reabsorption and promotes Hydro Vision iron excretion therefore insufficient production of this hormone can lead to retention of hydrogen ions diuretics such as spironolactone can block aldosterone receptors acetasolamide reduces bicarbonate reabsorption causing bicarbonate removal normal saline has a pH of around 5.5 and therefore can cause an acidosis total parental nutrition can result in the accumulation of hydrogen ions metabolic acidosis may be compensated by respiratory alkalosis metabolic alkalosis can be caused by loss of hydrogen ions or retention of bicarbonate ions you can lose hydrogen ions by prolonged vomiting or nasogastric tube suctioning as gastric secretions have high levels of hydrogen ions excessive urinary loss of hydrogen ions due to diuretics can also lead to metabolic alkalosis hypokalemia can also lead to metabolic alkalosis by causing High Vision ions to shift into cells whenever potassium moves into or out of cells high pressure ions move in the opposite direction to that to maintain electrical neutrality renal tubular disorders can cause metabolic alkalosis metabolic alkalosis may be compensated by respiratory acidosis in our next video we will teach you how to analyze the results of an ABG thank you for listening have a nice day