Acid Base Balancing
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- Normal Acid-base balance is
- 1:20
- Imbalances are classified as being ____________ or ____________.
- respiratory or metabolic
- Respiratory imbalances affect _________ _________ concentrations.
- carbonic acid
- Metabolic imbalances affet the base ____________.
- bicarbonate
- Normal valuses for pH
- 7.35-7.45
- Normal valuses for pCO2
- 35-45 mmHg
- Normal valuses for HCO3
- 20-30mmHg
- Normal valuses for pO2
- 80-100 mmHg
- Normal valuses for O2 saturation is
- 96-100%
- common cause of Respiratory acidosis
-
*abnormalities in pulmonary ventilation leading to CO2 retention.
*Halted or hindered gas exchange
*Obsructions preventing exhalation of CO2
*Impaired neuromuscular function or integerity of chest wall
*Depressed Respiratory center in medullat - Etiology of Respiratory acidosis
- ARDS, Pneumonia, Atelectasis, COPD, emphysema, asthma, bronchial burns, chest trauma, Guillain-Barre, MS, Mysathenia gravi, Drug overdoses, anesthesia, acute alcoholism.
- Compensatory mechanisms that take place within 24 hours of Respiratory Acidosis
-
Kidneys conserve HCO3 and excrete more hydrogen ions into urine
Urine becomes more acidotic - Clinical manisfestations or signs of respiratory acidosis
- Drowsiness, unconsciousness, disorientation, rapid, shallow respirations, tachycardia, dizziness, decreased BP, headache, Tachycardia, seizures
- Interventions for Respiratory acidosis
- Improve respiratory function, correct acidosis, assess for iatrogenic complications of interventions
- How can we improve respiratory function?
- antibiotics for infection, postural drainage, bronchodilators, inhalation therapy, breathing exercises, mechanical ventilation, oxygen therapy.
- What is the 2nd intervention in correcting respiratory acidosis? and how do we correct that?
-
Correct Acidosis
through treating hyperkalemia if present and IV sodium bicarbonate - What is the 3rd intervention in correcting respiratory acidosis? and what are some of them?
- assess for iatrogenic complications of interventions---tetany, CO2 narcosis, rebound respiratory alkalosis, metabolic acidosis.
- What results from excreting too much CO2?
- respiratory alkalosis
- Respiratory alkalosis is almost always a result of _________?
- hyperventilation
- Hyperventilation can be caused by 1._____________ 2.____________ 3.____________
- anxiety, aftermath of severe exercise and hypoxia at high altitudes
- Compensatory Mechanisms of Respiratory alkalosis
-
*Respirations decrease or even cease until CO2 levels rise enough to stimulate increase in respirations.
*Kidneys slow absorption of HCO3 and increase release of hydrogen ions causing alkaline urine - clinical manisfestations or signs of respiratory alkalosis are
- increased neuromuscular irritability, hyperreflexia, muscular twitching, seizures, lightheadedness,numbness and tingling in toes and fingers, tachycardia, dysrhythmias.
- What should the nurse do for a respiratory alkalosis pt.?
- Eliminate cause of hyperventilation, help person breathe more slowly and deeply (paper bag), if neurological problems is the cause, treat the primary problem.
- Most common cause of metabolic acidosis?
-
overproduction of metabolically produced acids found in diabetes mellitus,
Infections with high fever,
trauma, and major surgery. - other causes of Metabolic acidosis
- excessive ingestion of acid (aspirin, ferrous sulfate), Renal diseases( kidneys lose ability to secrete acids), abnormal loses of alkali (acute vomiting, loss of pancreatic, biliary and lower intestinal fluids
- clinical manisfestations of Metabolic acidosis
- drowsiness, coma, dehydration, n/v, diarrhea, headache,MOST COMMON is muscular twitching and deep rapid respirations (Kussmaul's breathing)
- Nursing interventions for metabolic acidosis
-
restore blood volume and osmolarity
Correct HCO3 deficit
assess for and prevent electrolyte imbalances (Hyperkalemia) and protect from injury. - Common causes of metabolic alkalosis
- excessive loss of hydrogen ions from body through vomiting and gastric suction w/o replacement of alkali
- Compensatory mechanisms of metabolic alkalosis
- hypoventilation (to keep some of the CO2), hydrogen ions are conserved and large amounts of sodium and potassium are excreted by the kidneys
- clinical manisfestations of metabolic alkalosis
- belligerence, irritable, disorientated, lethargy, shallow slow respirations, periods of apnea, tachycardia, dysrhythmias, n/v, hypertonic muscles, tingling of fingers and toes, seizures
- Nursing intervention for metabolic alkalosis
- treat primary condition, correct alkalosis, correct water sodium, chloride and potassium deficits.
- Metabolic Acidosis
- pH < 7.35
- pH indicates the number of
- Hydrogen Ions H+
- Metabolic acidosis cause
- excess acids
- Normal range for pH
- 7.35 - 7.45
- The acid base imbalance of a client with diabetic ketoacidosis is called?
- Metabolic acidosis
- condition in which acid accumulates in the body
- Acidosis
- Common Causes
- Acute respiratory conditions (pulmonary edema, pneumonia, acute asthma), opiate OD, foreign body aspiratio0n, chest trauma
- Your COPD patient has an acute exacerbation of the disease-- the acid base imbalance is?
- Respiratory acidosis
- A pt. is in pain and is anxious from an accident. The acid base imbalance is?
- Respiratory alkalosis
- condition in which base substances accumulate in the body
- Alkalosis
- A client has been taking extra lasix for “bloating”. The acid base imbalance is?
- Metabolic alkalosis
- Metabolic acidosis compensation
- rate and depth of respirations increase, eliminating additional CO2
- pH Up
- Alkalosis
- Interpret the ABG: ph 7.25, pCo2 54, HCO3 24, pO2 84
- Respiratory acidosis
- pH down
- acidosis
- Respiratory Acidosis
- pH < 7.35
- 1st step to blood gas interpretation
- look at pH and determin a/b status
- Interpret the ABG: ph 7.50, pCo2 28, HCO3 24, pO2 70
- Respiratory Alkalosis
- Metabolic Alkalosis
- pH > 7.45
- 2nd step to blood gas interpretation
- look at respiratory component to see if the imbalance is due to a respiratory reason
- Interpret the ABG: ph 7.19, pCo2 35, HCO3 26, pO2 85
- Impossible
- Metabolic alkalosis cause
- bicarb excess
- 3rd step to blood gas interpretation
- look at metabolic component to determine if imbalance is due to a metabolic reason
- Interpret the ABG: ph 7.50, pCo2 40, HCO3 30, pO2 90
- Metabolic Alkalosis
- Metabolic acidosis effect on ABGs
- decrease pH
- Interpret the ABG: ph 7.35, pCo2 50, HCO3 30, pO2 60
- Compensation
- Respiratory Alkalosis
- pH 7.45
- What is the normal ratio of base to acid?
- 20:1
- Interpret the ABG: ph 7.38, pCo2 30, HCO3 18, pO2 75
- Compensation
- Measures the pressure exerted by CO2 dissolved in the blood
- PCO2
- Metabolic alkalosis compensation
- rate and depth of respirations decrease, retaining CO2
- Respiratory component of blood gases
- PCO2
- Metabolic alkalosis effect on ABGs
- increase pH
- PCO2 normal values
- 35 - 45 mmHg
- Measures the amount of bicarbonate (base) in blood
- HCO3
- Respiratory acidosis cause
- retained CO2
- The system most critically affected ( can cause death) by severe abnormalities in potassium balance is?
- The cardiovascular system
- Acidosis that results from respiratory dysfunction is called?
- Respiratory acidosis
- Metabolic component of blood gases
- HCO3
- Respiratory acidosis compensation
- Kidneys conserve bicarb to resore carbonic acid:bicarb ration of 1:20
- Chronic obstructive lung disease is a primary cause of?
- Respiratory acidosis
- HCO3 normal values
- 22 - 26 mEq/L
- measures the patial pressure of O2 dissolved in blood
- PO2
- Respiratory acidosis effect on ABGs
- decrease pH
- Diabetes mellitus is a primary cause of?
- Metabolic acidosis
- indicates the ability of the lungs to allow Oxygen to diffuse into bloodstream
- PO2
- Respiratory alkalosis cause
- loss of CO2
- Normal range of PO2
- 80 - 100 mm Hg
- Respiratory alkalosis compensation
- Kidneys excrete bicarb and conserve H+ to restore carbonic acid: bicarb ratio
- Percentage of hemoglobin that is saturated w/ oxygen
- O2 saturation
- Respiratory alkalosis effect on ABGs
- increase pH
- each molecule of hemoglobin can carry how many molecules of oxygen?
- 4
- Normal value for O2 saturation
- 95 - 100%
- measures all the bases inteh blood that are available to help buffer
- Base Excess (BE)
- Normal value for base excess
- -2 to +2
- provides a more complete picture of body's ability to buffer
- Base Excess (BE)
- 3 causes of respiratory acidosis
- 1. primary lung function problem
- what condition is caused by increases in CO2 in blood causing an increase in H+
- respiratory acidosis
- in what condition does K+ move out of cells so H+ move into cells creating high serum potassium levels
- Acidosis
- in what condition do cells release H+ into the blood and K+ move into cells from blood serum causing low K+ levels
- Alkalosis
- in what condition does CO2 increase and HCO3 decrease?
- Acidosis
- in what condition does CO2 decrease and HCO3 increase?
- Alkalosis
- if pH is abnormal and both CO2 and HCO3 are abnormal, what is the compensation level?
- partially compensated
- if pH is abnormal and either, but not both, CO2 or HCO3 is abnormal, what is the compensation level?
- Uncompensated
- if pH is normal and both CO2 and HCO3 is abnormal, what is compensation level?
- Compensated
- what are some possible reasons for metabolic acidosis? (handout from class)
- Diabetic ketoacidosis, shock, kidney failure
- what are some reasons for respiratory acidosis (handout from class)
- sedation, shock, severe pneumonia
- what are some reasons for metabolic alkalosis
- vomiting, fever, tachypnea
- what are some reasons for respiratory alkalosis?
- hyper ventilation, pain, anxiety
- what acid/base condition is it and what may have caused it?
- part. compensated metabolic acidosis; Diabetic ketoacidosis
- HCO3: 28
- partially compensated resp. acidosis; asthma
- PCO3: 20
- partially compensated respiratory alkalosis; hyperventilation or pain
- PCO3: 32
- partially compensated metabolic alkalosis; vomiting
- HCO3: 34
- metabolic alkalosis, compensated; sedation