Acids and Bases Flashcards
When does respiratory acidosis occur and what does it lead to?
This occurs with decreased lung ventilation,
- leading to retained CO2,
- CO2 combines with water making H2CO3 (carbolic acid, weak)
- H2CO3 breaks up into H and HCO3 (bicarb)
- the acidic hydrogen goes into the blood
- which leads to decreased blood pH (acidotic)
What are 4 causes of respiratory acidosis?
- bradypnea
- damage to gas exchange structures
- damage to muscles used for breathing
What is CO2?
the acidic waste product of cell metabolism
CO2 level norm
35-45mmHg
What are some conditions that lead us to be bradypneic?
“DEPRESS”
Drugs
Edema
Pneumonia
Respiratory center of brain, damaged (stroke)
Emphysema
Spasms of bronchial tubes
Sac elasticity of alveolar sac damaged (COPD)
ABG in Respiratory Acidosis looks like
blood pH < 7.35
PaCO2 > 45mmHg
HCO3 < 22mEq/L
What is PaCO2 and the normal level?
the CO2 concentration in arterial blood,
norm is 35-45mmHg
What is a normal bicarb (HCO3) level?
22-26mEq/L
What does bicarb tell us in respiratory acidosis?
If the patient is compensating or not. If the level is normal, it is uncompensated.
If the level is higher, there is partial compensation.
S/S of respiratory acidosis
neuro - confused, drowsy, headache
- hypoxic
- bradypnea
- tachycardia
- hypotension
- CO2 increased
ABG in Respiratory Alkalosis looks like
blood pH > 7.45
PaCO2 < 35mmHg
HCO3 > 26mEq/L
Explain the thirst mechanism
- low fluid (high plasma osmolality, so low fluid and high solutes)
- hypothalamus response (osmoreceptors in hypothalamus releases ADH, makes you feel thirsty)
- Kidneys respond (ADH causes distal convoluted tube and collecting duct to reabsorb water)
- Water retained (water is reabsorbed and not excreted in urine, will normalize osmolality)
When does respiratory alkalosis occur and what does it lead to?
- occurs with increased lung ventilation (tachypnea)
- CO2 levels decrease and pH levels increase
What are some conditions that cause a patient to be tachypenic?
“TACHYPNEA”
Temp increased
Aspirin toxicity
Controlled vent too fast
Hyperventilation
Yelp (pain, anxiety, fear)
Pneumothorax
Neuro damage (inflammation or injury in brain)
Embolism in lungs
Ascending altitude (low oxygen level, causes hyperventilation)
What does bicarb tell us in respiratory alkalosis?
If bicarb is normal, it is uncompensated.
If bicarb is less than 22mEq/L, then it is partially compensated.
What can the kidneys do to help in respiratory alkalosis?
can tweak bicarb and hydrogen ions by excreting extra bicarb and retaining hydrogen.
S/S of respiratory alkalosis
- tachypnea
- neuro changes (anxiety, fear, dizziness, seizures)
- tachycardia
- tetany, muscle cramps, dysrhythmias (d/t hypocalcemia and hypokalemia)
Nursing interventions with respiratory alkalosis
“REST”
Rebreather mask
Electrolytes monitored
Sedatives or anti-anxiety meds
Teach relaxation and stress de-escalation techniques
When to use the Allen test and describe the steps.
Use to see if you can get an ABG.
- place pressure on radial and ulnar arteries
- patient squeeze and release fist multiple times
- release ulnar only (on pinky side)
- normal response will bring color back within 5 seconds, means you can use it to get ABG.
Describes RAAS (Renin-Angiotensin-Aldosterone- System)
- BP decreased indicating too much fluid loss
- Kidneys respond - juxtaglomerular cells release renin
- Liver responds - detects the renin in blood so it activates angiotensinogen, which turns into angiotensin I
- ACE - Angiotensin-Converting-Enzyme turns angiotensin I into angiotensin II
- Angiotensin II
- - -vasoconstriction (constricts blood flow to kidneys limiting ability to excrete water, keeps more water in blood to increase fluid volume and BP)
—-causes adrenal cortex to release aldosterone (leads kidneys to retain sodium and water, decreasing urination)
—-posterior pituitary gland to release ADH (kidneys keep water and increase blood volume, stimulates thirst mechanism)
When does metabolic alkalosis occur and what does it lead to?
- body loses excessive hydrogen ions which means the bicarb is high
- body compensates by hypoventilation
ABG in Metabolic Alkalosis looks like
blood pH > 7.45
PaCO2 > 45 mmHg
HCO3 > 26mEq/L
What are some conditions that cause a patient to be in metabolic alkalosis?
ALKALI
Aldosterone production increased
Loop diuretics
K eating food much foods that are alkalotic
Anticoag - citrate (storage in blood) (metabolized as bicarb)
Loss of fluid (NG suction, vomiting)
Increased bicarb administration
s/s of metabolic alkalosis
- bradypnea
- hypokalemia
- tetany
- tremors
- ECG changes
When does metabolic acidosis occur and what does it lead to?
The patient has too much acid buildup in body fluids causing HCO3 (bicarb) to decrease.
ABG in Metabolic Acidosis looks like
blood pH: < 7.35
HCO3: < 22
PaCO2: < 35
What are some conditions that cause a patient to be in metabolic acidosis?
ACIDOTIC
- Aspirin toxicity (high anion)
- Carbs not metabolized (high anion)
- Insufficiency of kidney function (high anion)
- Diarrhea (loss of HCO3) and DKA
- Ostomy drainage
- T, fisTula
- Intake of high fat diet (high anion)
- Carbonic anhydrate inhibitors
s/s of metabolic acidosis
hyperventilation, weak, confused, low BP, cardiac changes, nausea and vomiting
What is a normal anion gap?
10-14
What is the anion gap?
It is the difference between anions and cations in a patient’s lab values.
When would you see a high anion gap in acidosis?
Any condition where too much acid is produced and not enough bicarb
When would you see a normal anion gap in acidosis?
Any condition where the body loses bicarb.
