ABGs Flashcards
(51 cards)
1
Q
Purpose of ABG Interpretation
A
- Assessment of oxygenation status of blood
- Assessment of ventilation/gas exchange
- Assessment of acid/base balance
- Evaluation of treatments used to correct acid/base imbalances
2
Q
Measurement of Oxygenation
A
- PaO2
- A measure of the partial pressure (P) of oxygen dissolved in arterial blood plasma
- Normal Range: 80-100mmHg
3
Q
Measurement of Ventilation
A
- pH
- PaCO2
- HCO3
4
Q
pH
A
- The pH is the hydrogen ion. (H+) concentration of plasma
- Normal Range: 7.35-7.45
5
Q
PaCO2
A
- A measure of the partial pressure of carbon dioxide dissovled in arterial blood plasma
- LUNGS
- Normal Range: 35-45mmHg
6
Q
HCO3
A
- Bicarbonate (HCO3) is the acid-base component tht reflects kidney function
- HCO3 lvl is reduced or incrd in the plasma by renal mechanisms
- KIDNEYS
- Normal Range: 22-26mEq/L
7
Q
Acidosis
A
pH < 7.35
8
Q
Alkalosis
A
pH > 7.45
9
Q
Respiratory Acidosis
A
- pH < 7.35
- PaCO2 incrd, > 45mmHg
10
Q
Metabolic Acidosis
A
- pH < 7.35
- HCO3 dcrd, < 22mEq/L
11
Q
Respiratory Alkalosis
A
- pH > 7.45
- PaCO2 dcrd, < 35mmHg
12
Q
Metabolic Alkalosis
A
- pH > 7.45
- HCO3 incrd, > 26mEq/L
13
Q
PaO2 - Mild Hypoxemia
A
60-79%
14
Q
PaO2 - Moderate Hypoxemia
A
40-59%
15
Q
PaO2 - Severe Hypoxemia
A
<40%
16
Q
Base Range
A
- Base excess & base deficit reflect the nonrespiratory contribution to acid-base balance
- Normal Range: -2mEq/L to +2mEq/L
17
Q
High Base
A
- Base excess (> +2mEq/L)
- Indicates tht there is a higher than normal amnt of HCO3 in the blood, may be due to a primary metabolic alkalosis or a compensated respiratory acidosis
- The base excess is another surrogate marker of metabolic acidosis or alkalosis
18
Q
Low Base
A
- Base deficit (< -2mEq/L)
- Indicates tht there is a lower than normal amnt of HCO3 in the blood, suggesting either a primary metabolic acidosis or a compensated respiratory alkalosis
19
Q
Compensatory Responses
A
-
Responses by the lungs (Co2) and kidney (HCO3) to metabolic and respiratory disturbances
> respiratory compensation is rapid
> metabolic compensation is slow
20
Q
Uncompensated
A
-
pH = abnormal
> less than 7.35 or greater than 7.45 - PaCO2 &/or HCO3 = abnormal
- Body does not have enough time to return pH back to normal
21
Q
Compensated
A
-
pH = “normal”
> determine which side of 7.40 is closer to - PaCO2 & HCO3 = abnormal
- Body had enough time to restore pH back to normal
22
Q
Partial Compensation
A
- pH = abnormal
- PaCO2 = abnormal
- HCO3 = abnormal
- Body is attempting to return pH to normal
23
Q
Respiratory Acidosis - Uncompensated
A
- pH low (acidic)
- PaCO2 high (acidic)
- HCO3 normal
24
Q
Respiratory Acidosis - Partially Compensated
A
- pH low (acidic)
- PaCO2 incrd (acidic)
- HCO3 incrd (basic)
25
Respiratory Acidosis - Compensated
- **pH normal**
- **PaCO2 incrd (acidic)**
- **HCO3 incrd (basic)**
26
Respiratory Acidosis - Causes
- **Airway obstruction**
- **CNS depression**
> hypoventilation, opioids
- **Brain stem injury**
- **Sleep apnea**
- **Neuromuscular impairment**
- **Ventilatory restriction**
> asthma, COPD
- **Incrd CO2 production**
> shivering, rigors, seizures, malignant hyperthermia, hypermetabolism, incrd intake of carbs
- **Incorrect ventilator settings**
27
Respiratory Acidosis - Treatment
- **Treat underlying cause**
- **Oxygen**
- **Mechanical ventilation**
- **Suction**
- **Bronchodilators**
28
Respiratory Acidosis - Signs & Symptoms
- **R/T cause**
- **Confusion, lethargy, dyspnea, pale or cyanotic skin, mental cloudiness, restlessness, HTN, weakness, headache, incrd resp effort w/ nasal flaring/yawning, use of neck & upper body muscles**
- **Dcrd resp rate/hypoventilation**
> associated w/ dcrd function of resp center as in head trauma, oversedation, general anesthesia, metabolic alkalosis
- **Adventitious breath sounds (crackles, wheezes); stridor, crowing**
29
Respiratory Alkalosis - Uncompensated
- **pH high (basic)**
- **PaCO2 dcrd (basic)**
- **HCO3 normal**
30
Respiratory Alkalosis - Partially Compensated
- **pH low (basic)**
- **PaCO2 incrd (basic)**
- **HCO3 incrd (acidic)**
31
Respiratory Alkalosis - Compensated
- **pH normal**
- **PaCO2 dcrd (basic)**
- **HCO3 dcrd (acidic)**
32
Respiratory Alkalosis - Causes
- **Hypoxemia or hypoxia**
> lung disease, profound anemia, low FiO2
- **Incorrect ventilator settings**
- **CNS stimulation**
> fever, pain, fear, anxiety, CVA, cerebral edema, brain trauma/tumor, CNS infection
- **Pulmonary embolism**
33
Respiratory Alkalosis - Treatment
- **Treat the underlying cause**
- **Mechanical ventilation**
- **Buffers**
- **Have the pt rebreathe air tht has been exhaled**
> put on a non-rebreather on w/o oxygen
34
Respiratory Alkalosis - Signs & Symptoms
- **Deep rapid breathing (40+ bpm)**
- **CNS & neuromuscular disturbances**: lightheadedness, agitation, circumoral & peripheral paresthesias, carpopedal spasms, twitching & muscle weakness, N/V, muscle twitching
35
Metabolic Acidosis - Uncompensated
- **pH low (acidic)**
- **PaCO2 normal**
- **HCO3 dcrd (acidic)**
36
Metabolic Acidosis - Partially Compensated
- **pH low (acidic)**
- **PaCO2 dcrd (basic)**
- **HCO3 dcrd (acidic)**
37
Metabolic Acidosis - Compensated
- **pH normal**
- **PaCO2 dcrd (basic)**
- **HCO3 dcrd (basic)**
38
Metabolic Acidosis - Causes
- **Hypoxia**
- **Lactic acidosis**
- **Ketoacidosis**
- **Renal failure**
> uremic acidosis
- **GI loss of HCO3**
> diarrhea
- **Renal loss of HCO3**
> renal tubular acidosis, diamox
- **Poison**
> salucylate intoxication, methanol, ethylene glycol
- **Overconsumption of alcohol**
- **Rhabdomyolysis**
39
Metabolic Acidosis - Treatment
- **Treat the underlying cause**
- **Buffers**
40
Metabolic Acidosis - Signs & Symptoms
- **Headache**
- **Drowsiness & confusion**
- **Weakness**
- **Incrd resp rate & depth**
- **N/V**
- **Diminished cardiac output w/ pH < 7**
> results in hypotension, cold clammy skin, & cardiac arrhythmias
41
Metabolic Alkalosis - Uncompensated
- **pH high (basic)**
- **PaCO2 normal**
- **HCO3 incrd (basic)**
42
Metabolic Alkalosis - Partially Compensated
- **pH high (basic)**
- **PaCO2 high (acidic)**
- **HCO3 high (basic)**
43
Metabolic Alkalosis - Compensated
- **pH normal**
- **PaCO2 high (acidic)**
- **HCO3 high (basic)**
44
Metabolic Alkalosis - Causes: GI Loss of H+
- **Nasogastric suctioning**
- **Gastric lavage**
- **Prolonged vomiting**
45
Metabolic Alkalosis - Causes: Renal Loss of H+
- **Loop & thiazide diuretics**
- **Edematous states**
> heart failure, cirrhosis, nephrotic syndrome
- **Hyperaldosteronism**
- **Hypercortisolism**
- **Excess ACTH**
- **Exogenous steroids**
- **Hyperreninemia**
- **Severe hypokalemia**
- **Renal artery stenosis**
- **Bicarbonate administration**
- **Hypokalemia**
46
Metabolic Alkalosis - Causes: Retention/Addition of Bicarbonate
**Excessive quantities of antacids**
47
Metabolic Alkalosis - Treatment
- **Treat underlying cause**
- **KCL**
- **Volume**
- **Arginine monohydrochloride**
- **HCL**
48
Metabolic Acidosis Examples
- **DKA**
- **Renal failure**
49
Metabolic Alkalosis Examples
- **Chronic indigestion & use antacids daily**
> antacids are alkalotic
- **Long term nasogastric suctioning**
50
Narcotic Overdose
**Respiratory acidosis**
narcotics depress resp system
51
Anxiety Attack
**Respiratory alkalosis**
hyperventilation = breathing off too much CO2
