Arterial Blood Gases & Chest tubes Flashcards
What is the normal range for pH?
7.35-7.45
What is the normal range for PaCo2?
35-45
What is the normal range for PaHCO3?
22-28
What is the normal range for PaO2?
80-100
What is the normal range for base excess?
-2 to +2
What is the normal range for SaO2?
> 95%
What is the normal acid-to-base ratio?
1:20
What is the normal a/A gradient?
5-10 mmHg
What is the normal PF ratio?
normal >300
What is the normal arterial/total O2 content?
20
Describe how to perform the Allen test and why it is used.
Have the patient clench their fist tightly. Locate and occlude the radial and ulnar arteries. While occluding, have the patient release their fist and observe for blanching. Release the ulnar artery. The test is positive if redness returns in 5-15 seconds. This means the radial artery can be used for arterial blood gas sampling. The Allen test is performed first to make sure that the artery can be used for blood sampling, and that there is another artery to perfuse the hand if something goes wrong.
Describe why we would use pulse oximetry or capnography.
Pulse oximetry measures the O2 saturation of Hgb in the blood. Capnography measures the end tidal CO2. Pulse oximetry correlates with PaCO2 and helps measure hypoxia. Capnography is more accurate and is often used to measure respiratory depression (ie: opioid use) and the metabolism/efficiency of breathing.
What are the pH’s that result in death?
6.8 and 8.0
What are common causes of respiratory depression? BBOAAA
Brain injury
Blood transfusion reaction
Obstructive respiratory disease
post-op Anesthesia
neurologic Analgesics (opioids, sedatives)
respiratory acidosis, metabolic alkalosis
What are the risk factors of respiratory depression?
Opioid and PCA use
morbid obesity
age
What are the signs and symptoms of respiratory depression?
RR<12
shallow respirations
low O2 saturation/hypoxia
low CO2 on capnography
cyanosis
elevated HR
hard to arouse, drowsiness
What are the nursing interventions for respiratory depression?
administer Narcan if necessary. Several doses may be needed as Narcan has a short half-life.
administer oxygen
What are common signs and symptoms of acidosis?
hyperkalemia: confusion, muscle spasms, coma, respiratory distress, ECG changes (tall T-waves, wide QRS, long PR interval)
vasodilation: low BP, high HR, headache
What are some common causes of respiratory acidosis?
D drugs (opioids, sedatives, antianxiety, etc)
E edema (pul edema, pul effusion, pul HTN)
P pneumonia
R CNS damage
E emboli (or other lung obstruction)
S spasms (neuromuscular impairment)
S sac damage (lung dz: atelectasis, COPD, asthma)
What are common signs and symptoms of respiratory acidosis?
N: CNS depression, confusion, HA
C: low BP, high HR, dysrhythmia
R: hypoventilation
S: diaphoresis, flushing
Explain the physiology of respiratory acidosis.
Something causes the patient to hypoventilation. During hypoventilation, CO2 is not being excreted and builds up in the body, increasing the acid content of the blood. Excess acid causes vasodilation, which causes many of the symptoms seen in respiratory acidosis. The body compensates by stimulating the kidneys to secrete acid through the urine and to produce more HCO3 in order to increase the pH of the blood.
A patient is post-opt from knee surgery. The patient has been receiving Morphine 4 mg IV every 2 hours. You notice the patient is exhibiting a respiratory rate of 8 and is extremely drowsy. Which of the following conditions is the patient at risk for?
A. Respiratory acidosis
B. Respiratory alkalosis
C. Hypokalemia
D. Metabolic acidosis
What are the interventions you will take in this situation?
A. Respiratory acidosis.
The patient is experiencing respiratory depression and hypoventilation, which will increase the PaCO2 and decrease the pH.
Interventions:
- stop IV infusion
- administer oxygen
- provide respiratory assistance (deep breathing, ventilator)
A patient attempted to commit suicide by ingesting a bottle of Aspirin. Which of the following conditions is this patient at risk for?
A. Hyperkalemia
B. Hypercalcemia
C. Respiratory alkalosis
D. Respiratory acidosis
What are the interventions you will take in this situation?
C. Respiratory alkalosis
Aspirin toxicity can cause hyperventilation, fever, hypokalemia.
Interventions:
- administer IV NaHCO3
- slow down breathing (deep breathing, paper bag, ventilator)
- administer K+ if needed
Respiratory alkalosis can affect other electrolyte levels in the body. Which of the following electrolyte levels can also be affected in this condition?
A. Calcium and sodium levels
B. Potassium and sodium levels
C. Calcium and potassium levels
D. Potassium and phosphate levels
C. Calcium and Potassium levels
Respiratory alkalosis causes low CO2 levels in the blood. As a result, H+ will move out of the cells, and K+ and Ca++ will move into the cells to maintain ion balance. This causes hypokalemia and hypocalcemia.
A patient is experiencing respiratory alkalosis. What is the most classic sign and symptom of this condition?
A. Bradypnea
B. Tachypnea
C. Bradycardia
D. None of the options are correct
B. Tachypnea
A patient has the following blood gases: PaCO2 25, pH 7.50, HCO3 19. Which of the following could NOT be the cause of this condition?
A. Anxiety attack
B. Chronic obstructive pulmonary disease (COPD)
C. Fever
D. Aspirin toxicity
Is the condition chronic? Compensated?
B. COPD
PaCO2 25, pH 7.50, HCO3 19
PaCO2 = alkalosis
pH = alkalosis
HCO3 = acidic
The patient is experiencing chronic partially compensated respiratory alkalosis. COPD causes respiratory acidosis.
A patient on mechanical ventilation has the following blood gases: PaCO2 29, pH 7.56, HCO3 23. Which of the following conditions is the patient experiencing?
A. Respiratory alkalosis not compensated
B. Respiratory alkalosis partially compensated
C. Respiratory alkalosis fully compensated
D. Respiratory acidosis partially compensated
Is the condition chronic?
A. Respiratory Alkalosis not compensated
PaCO2 29, pH 7.56, HCO3 23
PaCO2 = alkalosis
pH = alkalosis
HCO3 = normal
The patient is experiencing acute respiratory alkalosis. It is not compensated b/c the pH is still high and HCO3 is wnl.
A patient is experiencing respiratory acidosis due to brain trauma. Which of the following lab values correlates with this acid imbalance?
A. Potassium level of 6.0
B. Potassium level of 2.5
C. Potassium level of 5.0
D. Potassium level of 3.5
A. Potassium level of 6.0
Respiratory acidosis can cause hyperkalemia. The normal range of K is 3.5-5.0.
Which patient is experiencing partially compensated respiratory acidosis?
A. PaCO2 30, pH 7.35, HCO3 26
B. PaCO2 53, pH 7.23, HCO3 28
C. PaCO2 45, pH 7.49, HCO3 21
D. PaCO2 50, pH 7.30, HCO3 23
Is the condition chronic?
B. PaCO2 53, pH 7.23, HCO3 28
PaCO2 = acidic
pH = acidic
HCO3 = normal to high
The patient is experiencing respiratory acidosis. It is partially compensated because the HCO3 is slightly high.
It is mildly acute or just starting to become chronic because the HCO3 is starting to rise.
Which of the following is not a cause of respiratory acidosis?
A. Pulmonary emboli
B. Asthma
C. Chronic obstructive pulmonary disease (COPD)
D. Hyperventilation
D. Hyperventilation
Hyperventilation causes respiratory alkalosis. Hypoventilation causes respiratory acidosis.
A patient with COPD has the following blood gases: PCO2 59, pH 7.26, HCO3 42. Which of the following conditions is presenting?
A. Respiratory alkalosis
B. Respiratory acidosis
C. Metabolic alkalosis
D. Metabolic acidosis
Is the condition chronic? Compensated?
B. Respiratory acidosis
PCO2 59, pH 7.26, HCO3 42
PaCO2 = acidic
pH = acidic
HCO3 = high
The patient is experiencing chronic respiratory acidosis with partial compensation.
What are the indications for tracheal intubation?
Respiratory acidosis with PaCO2 >50 and worsening respiratory distress.
What are the interventions for respiratory acidosis caused by pneumonia (6)?
- administer antibiotics
- high fowler’s position
- administer O2
- breathing assistance if necessary & incentive spirometer
- encourage coughing
- administer IV fluids
What the common signs and symptoms of alkalosis?
Neuromuscular irritability: CNS irritation, numbness, tingling, weakness, muscle twitch, seizure, arrhythmia, carpopedal spasms
What are some common causes of respiratory alkalosis?
T temperature (fever) -> hyperventilation
A aspirin toxicity
C controlled ventilation error
H hyperventilation
Y hysteria (anxiety, fear, psych disorder)
P pain
N neurologic (CNS stimulation - cocaine)
E embolism/edema -> hyperventilation
A asthma
Explain the pathophysiology of respiratory alkalosis.
Hyperventilation causes excess excretion of CO2, which decreases the acid in the system. The body detects the decreased pH and stimulates the kidneys to decrease acid excretion and bicarbonate production. Hyperventilation can cause some of the symptoms of alkalosis, such as weakness, lightheadedness, vertigo, tinnitus, and tachycardia. Alkalosis can cause hypokalemia and hypocalcemia as H+ ion moves out of the cell to correct the drop in pH. K+ and Ca++ ions then move into the cell to preserve ion balance, taking the ions out of the blood. Hypokalemia and hypocalcemia cause the other symptoms of neuromuscular irritability, such as muscle spasms, carpopedal spasms, numbness, tingling, seizure, and arrhythmias.
What are some common signs and symptoms of respiratory alkalosis?
N: CNS irritability, seizure, fatigue, tinnitus, vertigo
C: low BP, high HR, ECG changes (U-wave, ST depression), arrhythmia
R: hyperventilation
S: muscle spasms, muscle twitch, paresthesia, Chvostek sign +
low K+/Ca++
What are some common signs and symptoms of respiratory alkalosis?
N: CNS irritability, fatigue, tinnitus, vertigo
C: low BP, high HR, ECG changes (U-wave, ST depression), arrhythmia
R: hyperventilation
S: muscle spasms, muscle twitch, paresthesia, Chvostek sign +
low K+/Ca++