Presentation on theme: "NUR 101 M. Gardner Copyright2/4/2013. In order to meet homeostasis, the body fluids must maintain a stable chemical balance of hydrogen ions in body."— Presentation transcript:
In order to meet homeostasis, the body fluids must maintain a stable chemical balance of hydrogen ions in body fluids. This is done by regulating their acidity /alkalinity. Deviation from a normal value indicates that the client is experiencing an acid/base imbalance
ACID – substance that releases hydrogen ions (H+) BASE – accept hydrogen ions in solution This relationship is measured as pH.
Measurement of ABGs involves analysis of several components: pH PCO2 PO2 HCO3
Arterial blood gas analysis pH – measures the hydrogen ion concentration it is an indication of the blood’s acidity or alkalinity. Normal pH of body fluids is 7.35-7.45 pH 7 is neutral pH 7 is alkaline (base) acidic----neutral----alkaline
PaCO2/PCO2 35-45mmHg Carbon dioxide/CO2 Reflects adequate ventilation by the lungs Hyperventilation occurs PaCO2 <35mmHg. RR/depth increases the more carbon dioxide is exhaled Hypoventilation occurs PaCO2>45mmHg. RR/depth decreases, more carbon dioxide is retained – increasing the concentration of CO2
HCO3 /Bicarbonate normal range 22-26mE/L base regulated by the kidneys the kidneys excrete and retain HCO3 to maintain a normal acid/base balance is a principal buffer of the ECF compartment < 22mEq/L – indicates metabolic acidosis >26meq/L – indicates metabolic alkalosis
PO2 – oxygen in arterial blood Normal range – 90-100mmHg
Several body systems are actively involved in maintaining the narrow pH range necessary for optimal function. This includes buffers, respiratory system, renal system Buffers maintain acid/base balance by neutralizing excess acids/bases The lungs/kidneys help maintain a normal pH by either excreting/retaining acid/bases.
A strong acid added to the ECF causes the bicarbonate to become depleted neutralizing the acid pH drops acidosis A strong base is added to the ECF, depleting carbonic acid the pH rises alkalosis Buffer reaction is immediate
Lungs regulate acid/base balance by eliminating or retaining carbon dioxide (CO2) Carbon dioxide powerful stimulator of the respiratory center CO2 +H2O=H2CO3 this reaction is reversible
Kidneys kick in by excreting or retaining bicarbonate and hydrogen ions. Slower to respond to changes hour/days to correct imbalances
Excessive hydrogen ions are present and the pH falls (acidosis) kidneys reabsorb bicarbonate & excrete hydrogen ions. With alkalosis and high pH excess bicarbonate is excreted and hydrogen ions are retained.
pH 7.35 – 7.45 Pa CO2 35-45 mm Hg PaO2 80 -100 mm Hg HCO3 22-26 mEq/L O2 Saturation 95-100%
Are classified as respiratory or metabolic considering the general/underlying cause of the disorder. Respiratory acidosis/alkalosis retention/excretion of CO2 Bicarbonate /hydrogen levels are regulated by the kidneys, any problems metabolic acidosis/alkalosis
Client hypoventilates CO2 builds up in the bloodstream and the pH drops below normal. Kidneys try to compensate by conserving bicarbonate raises the pH pH <7.35 PaCO2 >45 HCO3 normal or elevated if compensating
The patient comes to the ER with complaint of vomiting for 3 days. Which acid base imbalance is she at risk for? The patient has just returned from surgery. He was medicated twice with narcotic analgesics in the PACU. He is difficult to arouse and has a respiratory rate of 12. what acid/base imbalance is he at risk for?