Acid Base Balance

Front 1

Acid Base Balance #1

Back 1

•essential for proper cell function
•depends on regulation of free hydrogen ions
•pH = “power of Hydrogen”
•Hydrogen comes from food/fluid we ingest

Front 2

Acid Base Balance #2

Back 2

•inverse proportion
__^_ # H = ___ pH (acid)
___ # H = __^_ pH (alkaline/base)
*When one goes up another goes down.

Front 3

Acid Base Balance #3

Back 3

•pH reflects balance b/w carbon dioxide (CO2) regulated by lungs (Respiratory)and bicarbonate(HCO3) regulated by kidneys (metabolic)
20:1 bicard to carbonic acid ratio

Front 4

Acid Base Balance Goal

Back 4

•GOAL: maintain homeostasis of H in body fluids

Front 5

Acid Base Balance #4

Back 5

•body fluids classified as acids or bases
acid – plenty of H = H donor
base – very little H = H acceptor

Front 6

Acid Base Balance #5

Back 6

•normal blood pH 7.35 – 7.45
< 6.8 or > 7.8 = death

Front 7

ACIDOSIS

Back 7

(pH < 7.35) excess H from acid excess or base deficit

Front 8

ALKALOSIS

Back 8

(pH > 7.45) deficit of H from base excess or acid deficit

Front 9

acid base balance evaluated

Back 9

ABG (arterial blood gas) obtained from radial, brachial, femoral artery, an arterial line, pulmonary artery

Front 10

other methods to evaluate acid base balance

Back 10

pulse oximetry
serum anion gap measurement
serum potassium (K+) level
carbon dioxide (CO2) level
chloride level

Front 11

normal blood pH

Back 11

7.35 – 7.45
< 6.8 or > 7.8 = death

Front 12

What does ABG's do?

Back 12

1.determine acid base status
2.eval. pulm gas exchange 3.assess resp.system 4.eval blood oxygenation
5.monitor resp. therapy

Front 13

•CO2 is a potential ________***

Back 13

Acid

Front 14

PaCO2 =

Back 14

RESPIRATORY COMPONENT (think CO2 in lungs)

Front 15

HCO3 =

Back 15

METABOLIC COMPONENT

Front 16

Acid Base Norms.

Back 16

pH 7.35 - 7.45
pa CO2 35 - 45
HCO3 22 - 26
Base excess -2 - +2
pa O2 80 - 100 mm Hg
sa O2 95 - 100 %

Front 17

6 Parameters of ABGs

Back 17

1.pH
2.partial pressure of CO2 in art. blood (PaCO2)
3.bicarbonate (HCO3) concentration
4.base excess
5.bartial pressure of O2 in art. blood (PaO2)
6.oxygen saturation (O2 sat.)

Front 18

Bicarb =

Back 18

Base

Front 19

normal or borderline pH (7.35 – 7.45) may indicate

Back 19

normal acid base balance OR the body’s attempts to compensate for a slightly abnormal or chronic acid base imbalance – you must analyze PaCO2 and HCO3 levels to determine this

Front 20

PaCO2 = respiratory acid base component

Back 20

↑ 45 = Hypoventilation= (CO2 retention-hypercapnia) = ACIDOSIS slow breathing
↓ 35 = Hyperventilation=(excessive CO2 loss-hypocapnia) = ALKALOSIS fast breathing

Front 21

HCO3 (Bicarb is Base) Metabolic acid base component

Back 21

↑ 26 = ___Alkalosis_
↓ 22 = ___Acidosis

Front 22

Base excess

Back 22

+ 2 = base excess (met. alkalosis)
- 2 = base deficit (met. acidosis)

Front 23

PaO2/SaO2

Back 23

oxygenation

Front 24

PaO2 < 80 =

Back 24

hypoxemia or older pt (subtract 1 mm Hg / year of age p 60) look at baseline on older / COPD client

Front 25

Electrolyte shifts

chloride – bicarbonate
(Cl- = HCO3-)

Back 25

If bicarbonate enters the red blood cell, chloride moves out into the extracellular fluid and the reverse is true. Note that the ionic charge is the same (negative) in order to maintain electronic balance.

Front 26

Electrolyte shifts

potassium – hydrogen
(K+ = H+)

Back 26

When extracellular hydrogen ion concentration increases (acidosis), potassium ions will move out of the cell into the extracellular fluid and hydrogen moves into the cell and hydrogen ions move out. Again note that the ionic charge for both is positive.

Front 27

What compensates for METABOLIC acid-base imbalances).Second line of defense against acid-base imbalances regulate blood levels of carbon dioxide. CO2 combines with water to form carbonic acid. Increased levels of carbon acid lead to a decrease in pH (acidosis).
_____ fixes Kidneys.

Back 27

Lungs

Front 28

What compensates for RESPIRATORY acid-base imbalances The kidneys can reabsorb or excrete acids and bases into the urine. They can also produce bicarbonate to replenish lost supplies. Adjustments to pH made by the kidneys can take hours to days.If the blood contains too much acid or not enough base, the pH drops and the kidneys reabsorb bicarbonate and excrete hydrogen. This also causes the kidney to form bicarbonate in the tubules.
______ fixes Lungs

Back 28

Kidneys

Front 29

CO2 =

Back 29

Respiratory component

Front 30

HCO3 =

Back 30

Metabolic component

Front 31

pH 7.1
CO2 63
HCO3 28

Back 31

Uncompensated Res. Acidosis

Front 32

pH 7.51
CO2 28
HCO3 25

Back 32

Uncompensated Res. Alkalosis

Front 33

pH 7.54
CO2 44
HCO3 35

Back 33

Uncompensated Metabolic Alkalosis

Front 34

pH 7.41
CO2 39
HCO3 25

Back 34

Normal

Front 35

pH 7.12
CO2 58
HCO3

Back 35

Uncompensated Res/Met Acidosis

Front 36

pH 7.36
CO2 55
HCO3 34

Back 36

Compensated Resp. Acidosis

Front 37

pH 7.43
CO2 30
HCO3 20

Back 37

Compensated Resp. Alkalosis

Front 38

Respiratory Acidosis

Back 38

Keeping in too much C02
Kidneys hold HCO3 & release H+

Front 39

Respiratory Acidosis General Info.

Back 39

1.Respiratory acidosis occurs when alveolar hypoventilation results in increased serum carbon dioxide levels.
2.Alveolar hypoventilation is the most common cause of respiratory acidosis.
3.The kidneys attempt to compensate by increasing the renal reabsorption of _HC03 and by excreting Hydrogen. This can take 24 to 48 hours.

Front 40

Causes of Respiratory Acidosis

Back 40

1.Pneumonia
2.COPD
3.Oversedation
4.Respiratory arrest
5.Airway obstruction
6.Cystic fibrosis
7.Brain trauma or tumor causing excessive pressure on the respiratory center
8.Obesity

Front 41

Clinical Manifestations of Respiratory Acidosis

Back 41

1.Hypoventilation respirations (slow)
2.Dyspnea
3.Dizziness
4.Tremors
5.Warm flushed skin
6.Asterixis
7.Tachycardia
8.Confusion
9.Coma

Front 42

Treatment of Respiratory Acidosis

Back 42

1. Treat Cause
2. Apply 02
3. Approve ventilation (sit them up, lift HOB
4. Avoid sedatives and narcotics
5. Give HC03-increase bicarb faster the kidney
6. Suction

Front 43

Nursing Diagnosis Respiratory Acidosis

Back 43

1. Impaired gas exchange
2. Altered mental status
3. altered tissue perfusion
4. Alteration in health main. secondary to COPD

Front 44

Nursing Implications of Respiratory Acidosis #1

Back 44

1.Encourage the patient to turn, cough, and breathe deeply every 2 hours to improve ventilation
2.Maintain a patient airway through suctioning to prevent CO2 retention
3.Monitor ABG levels
4.Monitor vital signs particularly respiratory rate and depth
5.Position the patient in the semi-Fowler’s or orthopneic position to ease breathing
6.Encourage the patient to drink 2 to 3 liters of fluids per day unless contraindicated to help thin secretions and aid in expulsion

Front 45

Nursing Implications of Respiratory Acidosis #2

Back 45

7.Administer supplemental O2 but be cautious with the patient with COPD because O2 will depress ventilatory drive (in these patients hypoxia is the stimulus to breathe)
8.Monitor serum potassium (K) levels for hyperkalemia because K moves out of the cell during respiratory acidosis
9.Administer meds such as bronchodilators for bronchospasms and antibiotics for respiratory infection
10.Administer sedatives cautiously because these could depress respirations
11.Assist with intubation
Check Baseline before calling Doc.

Front 46

Respiratory Alkalosis

Back 46

Release HCO3, Hold H+-
Greater than 7.41 and Less than 35

Front 47

Respiratory Alkalosis General Info

Back 47

1.Respiratory Alkalosis occurs when alveolar Hyperventilation results in decreased serum CO2 levels
2.Decreased CO2 levels lead to decreased H2CO3 (Carbonic Acid) production
3.The kidneys attempt to compensate by increasing renal excretion of_HCO3_, but this can take 24 to 48 hours

Front 48

Causes of Respiratory Alkalosis
Hyperventilation secondary to:

Back 48

Anxiety or hysteria Overventilation with mechanical ventilator Fever Pain Sepsis Brain trauma

Front 49

Clinical Manifestations of Respiratory Alkalosis

Back 49

1.Hyperventilation respirations
2.Light headedness
3.Vertigo
4.Headache
5.Paresthesia
6.Tinnitus
7.Palpitations
8.Syncope (loss of consciousness/fainting)
9.Convulsions
10.Coma

Front 50

Treatment of Respiratory Alkalosis

Back 50

1. Treat Cause
2. Increase CO2-rebreather mask, or rebreathe into paper bag
3. Sedation if possible

Front 51

Nursing Diagnosis for Respiratory Alkalosis

Back 51

1. Anxiety
2. Impaired gas exchange
3. Decreased cardiac output
4. altered home maintenance
5. activity intolerance

Front 52

Nursing Implications for Respiratory Alkalosis #1

Back 52

1.Monitor vital signs specifically respiratory rate and depth
2.Instruct the patient to breathe slowly and less deeply to decrease CO2 loss
3.If necessary have the patient breathe into a paper bag or use a rebreather mask to rebreathe CO2
4.Administer sedatives as ordered to slow the respiratory rate but monitor closely for respiratory depression and CO2 retention
5.Intervene prn to relieve pain or anxiety as this could cause or worsen hyperventilation

Front 53

Nursing Implications for Respiratory Alkalosis #2

Back 53

6.Monitor ABG values particularly PaCO2 levels
7.Monitor serum potassium levels because K is exchanged for H ions and moves from the extracellular to the intracellular space resulting in low serum K levels
8.Monitor laboratory results for values indicating compensation such as decreased HCO3 levels and normalization of pH
9.Provide emotional support

Front 54

K+ and H+ can't...

Back 54

Be in the same place

Front 55

Metabolic Acidosis

Back 55

Holds H+, releases HCO3

Front 56

Metabolic Acidosis General Information

Back 56

1.Metabolic Acidosis results from excessive accumulation of fixed acids or loss of fixed bases in body fluids
2.Fixed acids, such as hydrochloric acid, are produced by metabolism of ingested food
3.The respiratory system attempts to compensate through Hyperventilation (gets rid of CO2); respiratory compensation begins within minutes but takes several hours to take full effect

Front 57

Causes of Metabolic Acidosis

Back 57

1.Diabetic Ketoacidosis-very high sugar
2.Salicylate toxicity-aspirin overdose
3.Acute or chronic renal failure
4.TPN
5.Severe diarrhea (excessive loss of alkaline secretions from intestines and pancreas) *Got rid of base then left acid (so acidosis)
6.Diuretic therapy (excessive loss of HCO3 through kidneys)

Front 58

Clinical Manifestations of Metabolic Acidosis

Back 58

1.Hperventilations Respirations (_Kussmauls)
2.Lethargy
3.Drowsiness
4.Headache
5.Confusion
6.Fruity breath
7.Flushed warm skin
8.Nausea and vomiting
9.Convulsions, coma

Front 59

Treatment of Mebabolic Acidosis

Back 59

1. Correct cause
2. Bicard IV
3. Fluid and Electrolyte
4. Insulin (for diabetic)
5. dialysis-filer it out from your blood.

Front 60

Nursing Diagnosis for Metabolic Acidosis

Back 60

1. Fatigue
2. Dist. thought process
3. In Br pattern

Front 61

Nursing Implications for Metabolic Acidosis #1

Back 61

1.Monitor patients at risk for metabolic acidosis (diabetes mellitus, sepsis, shock)
2.Monitor VS
3.Monitor ABG values
4.Monitor HCO3 and K levels; low HCO3 and high K levels may be an early sign of acidosis

Front 62

Nursing Implications for Metabolic Acidosis #2

Back 62

5.Administer sodium bicarbonate cautiously through existing IV line in a large vein
6.Provide cardiac monitoring
7.Administer IV fluids containing lactate, lactate is converted to HCO3 in the liver
8.If the patient is acidotic due to hyperglycemia administer insulin
9.In renal failure, drug overdose, poisoning, assist with peritoneal dialysis or hemodialysis to correct pH

Front 63

Random Metabolic Acidosis info

Back 63

Kidneys are getting rid of too much base HCO3
Lungs blow off CO2

Front 64

Metabolic Alkalosis

Back 64

Caused by:
Holding HCO3 or losing acids so lung holds C)2

Front 65

Metabolic Alkalosis General Info

Back 65

1.Metabolic Alkalosis results from excessive accumulation of fixed bases or excessive loss of fixed acids in body fluids
2.A major cause is loss of a fixed acid such as HCL from the stomach via NG suctioning or excessive vomiting
3.The lungs attempt to compensate through hypoventilation

Front 66

Metabolic Alkalosis Causes

Back 66

1.Excessive NG suctioning
2.Excessive vomiting
3.Ingestion of large amounts of sodium bicarbonate
4.Prolonged diuretic therapy, esp. potassium wasting
5.Cushing’s Syndrome

Front 67

Metabolic Alkalosis Clinical Manifestations

Back 67

1.Hypoventilation
2.Dizziness
3.Paresthesia in fingers and toes
4.Circumoral paresthesia
5.Confusion
6.Irritability
7.Convulsions and coma

Front 68

Metabolic Alkalosis Treatment

Back 68

1. Treat cause
2. IV fluids and elec. replacements (esp K+)
3. Stop diuretics
4. stop suctionsing
5. antiemetics

Front 69

Metabolic Alkalosis Nursing Diag.

Back 69

1. Altered mental status
2. decrease cardiac output
3. high risk for injury
4. fluid volume deficit

Front 70

Metabolic Alkalosis Nursing Implications #1

Back 70

Monitor patients at risk for metabolic alkalosis (excessive vomiting or prolonged NG suctioning)
2.Assess fluid intake and output to determine the amount of gastric fluid loss
3. Monitor vital signs, especially respirations, which usually decrease as the body attempts to conserve CO2
4.Control vomiting, administer antiemetics
5.Administer IV fluid and electrolyte supplements to replace fluid volume, K and chloride losses

Front 71

Metabolic Alkalosis Nursing Implications #2

Back 71

Monitor electrolytes
Monitor heart rate and rhythm to detect hypokalemia
Warn the patient and family about the danger of excessive HCO3 ingestion
Teach the patient about K wasting diuretics to watch symptoms of hypokalemia such as weakness and excessive urine output; teach to replace K either by increased dietary intake of K rich foods or oral supplements (bananas, dried fruit and potatoes)