Tests & Lab Values Flashcards
SpO2/SaO2:
norms = 95-100%
Below 88-90% usually requires supplemental O2
PaO2:
norms = 75-100 mmHg
> 100 mmHg = hyperoxygenation
<80 mmHg = hypoxygenation
PaCO2:
norms = 35-45 mmHg
> 45 mmHg = COPD, hypoventilation
<35 mmHg = hyperventilation, pregnancy, PE & anxiety
Blood pH:
norms = 7.35-7.45
<7.35 = acidic; respiratory acidosis = hypoventilation or metabolic acidosis: CO2 retainer
> 7.45 = basic; respiratory alkalosis= hyperventilation or metabolic alkalosis: vomiting, diuretics; low CO2
Type of coagulation tests =
prothrombin time (PT) = evaluates ability to clot
International Normalized Ratio (INR) = ensures that results from PT tests are the same from one lab to another
Partial thromboplastin time (PTT) = determines if blood-thinning therapy is effective
Prothrombin Time (PT):
norms = 11-15 sec
> 15 sec = clotting deficiency, hemorrhagic ds, cirrhosis, medication (warfarin)
Partial Thromboplastin Time (PTT):
norms = 25-40 sec
> 40 sec = see above
International Normalized Ratio(INR):
norms = 0.9-1.1
Look for signs of bleeding
Use compensatory strategies to reduce risk of falls or injury
Patients with DVT, PE, mechanical valve, AF = on anticoagulation therapy will have target INF 2-3; higher if genetic clotting condition INF 3.5
C-reactive protein (CRP):
norm = <10 mg/L
> 10 mg/L = platelet disorder, increase risk of atherosclerosis
> 100 mg/L = associated with inflammation & infection
White Blood Cells (WBC):
norms = 4,300-10,800 cells/mm3
Indicative of immune system status
> 10,800 = infection, inflammation, cancer, corticosterioids
<4,300 = aplastic anemia, folate deficiency; increased risk of infection
Wear mask when working with immunosuppressed patients
Red Blood Cells (RBC):
Male: 4.6-6.2 106/uL
Female: 4.2-5.9 106/uL
Increased levels = polycythemia; fatigue with activity
Decreased levels = anemia; Fatigue with activity
Hematocrit (Hct):
% by volume of RBC in whole blood
Male: 45-52%
Female: 37-48%
Increased levels = polycythemia, dehydration, shock
Decreased levels = severe anemia, acute hemorrhage
Decreased exercise tolerance, increased fatigue, and tachycardia
Hemoglobin (Hgb):
oxygen carrying protein
Male: 13-18 g/dL
Female: 12-16 g/dL
Increased levels = polycythemia, dehydration, shock
Decreased levels = anemia, hemorrhage, cancer, sickle cell disease
Decreased exercise tolerance, increased fatigue, and tachycardia
Platelet Count:
150,000-450,000 cells/mm3
Increased = chronic leukemia
Decreased = acute leukemia, anemia
Look for active signs of bleeding hematuria, petechiae
Platelet count and exercise guidelines:
<20,000: AROM, ADLs only
20,000-30,000: light exercise only
30,000-50,000: moderate exercise
Heart rate norms:
infants = 120 bpm
adults = 60-100bmp
BP norms:
infants = 75/50 mmHg
adults = <120/80 mmHg
RR norms:
infants = 40 br/min
adults = 12-20 br/min
PaO2 (ABG) norms:
infants = 75-80 mmHg
adults = 75-100 mmHg
PaCO2 (ABG) norms:
infants = 34-54 mmHg
adults = 34-45 mmHg
pH (ABG) norms:
infants = 7.26-7.41
adults = 7.35-7.45
Tidal volume norms =
infants = 20mL
adults = 500mL
Temperature norms =
infants = 97.9F
adults = 98.6 F (37C)
What is respiration?
Respiration: gas exchange across the alveolar-capillary and capillary-tissue interface
What is respiration measured by?
Arterial Blood Gases (ABG)
What is O2 saturation?
SpO2 or SaO2
What is the Ventilation/Perfusion ratio (V/Q match)?
Norm 0.7 - 0.8
< 0.7 = poor ventilation
> 0.8 = poor perfusion
What is diffusion?
movement of solutes from area of higher to area of lower concentration
What is ventilation?
(Ve) the physical act of moving gas, primarily oxygen (O2) and carbon dioxide (CO2), into and out of the lungs
Ve= Tidal Volume (Vt) normal breathing at rest x Respiratory Rate (RR)
Ventilation Normal adult values
(Ve, Vt, RR):
Ve: 6.0 –10.0 L/min at rest
Vt: 400 –850 ml per breath or .40 - .85 L/breath
RR: 12 – 20 breaths per minute (bpm)
What is FiO2?
Fraction of inspired oxygen
The % of oxygen at each inspired breath
What is the FiO2of atmospheric room air?
21%
What is respiratory failure?
Etiology: Inadequate gas exchange by the pulmonary system
initiated by critical drop in blood oxygen level (hypoxemia) and/or a rise in arterial carbon dioxide (hypercapnia)
PaO2<60mmHg or PaCO2 >50mmHg
What is arterial blood gas (ABG)?
Blood sample taken from an artery = Invasive
Analysis assesses a patient’s partial pressure of oxygen (PaO2) and carbon dioxide (PaCO2)
Provides information about the patient’s oxygenation status and ventilation status
Hyperventilation (low CO2) and hypoventilation (high CO2) affect blood gas = resulting in a change in pH status of the blood
Pulmonary Assessment: Arterial Blood Gases
Assessment of the lungs ability to oxygenate the blood and remove carbon dioxide
assessment of problems related to acid-base balance, ventilation and oxygenation
Measures the pH, and the levels of oxygen (O2) and carbon dioxide (CO2) from an artery
The analysis of the partial pressure of gases within the arterial blood indicates the effectiveness of alveolar ventilation
CO2 levels =
High CO2 = acidic
Low CO2 = alkaline
What is ABG: Partial Pressure?
dynamic that explains why oxygen moves from the alveoli (oxygenated blood) into the capillaries (deoxygenated blood) and why carbon dioxide moves from the blood into the alveoli
Normal Dynamics: Partial pressure of oxygen is higher in the alveoli than the adjacent capillaries, it flows into the capillaries
since the partial pressure of carbon dioxide is higher in the capillaries than the alveoli, it moves from the capillaries into the alveoli
Invasive Assessment of ABG =
- The blood pH: norm 7.35-7.45
- Partial Pressure of Carbon dioxide (PaCO2): Norm 35 – 45 mm Hg
- Partial Pressure of Oxygen (PaO2): Norm 75 – 100 mm Hg
- Amount of serum bicarbonate (HCO3): Norm 22 – 26 mmol/L
Non-Invasive Assessment of ABG =
Oxygen Saturation (SpO2): Norm 94 – 100%
Normal ABG values:
pH = 7.35-7.45
PaCO2 = 35-45
HCO3 = 22-26
PaO2 =80-100
SaO2 = 94-100
what does low pH lead to?
acidemia
high PCO2 -= respiratory acidosis
OR
low HCO3 = metabolic acidosis
what does high pH lead to?
alkalemia
low PCO2 -= respiratory alkalosis
OR
high HCO3 = metabolic alkalosis
Pulmonary Assessment: Respiratory Alkalosis vs Acidosis
Order of values to look at:
pH first
PaCO2 is the next value to be determined - Compare the PaCO2 direction of the change with the direction of the change in pH
what is the Inverse relationship between PaCO2 and pH:
PaC02 decreases (less than 35mmHg) & pH increases (>7.45) - Respiratory Alkalosis
PaC02 increases (more than 45mmHg) & pH decreases (<7.35) - Respiratory Acidosis
Direct relationship between bicarbonate and pH: metabolic
increase bicarbonate, increase pH
decrease bicarbonate, decrease pH
Normal range is 22 to 26 millimoles per liter (mmol/L)
When the direct relationship is evident, the primary cause of the altered pH is of a ___ etiology
metabolic
What is Metabolic acidosis?
HCO3 <24 mmol/L
pH = decrease
PaCO2 = WNL
HCO3 = decreae
causes: Diabetic, diarrhea
signs/symptoms: Nausea, lethargy, secondary hyperventilation, coma
What is Metabolic alkalosis?
HCO3 >24 mmol/L
pH = increase
PaCO2 = WNL
HCO3 = increaes
causes: HCO3 ingestion, vomiting, diuretics
signs/symptoms: Weakness, mental dullness
What is respiratory alkalosis?
pH = increase
PaCO2 = decrease
HCO3 = WNL
causes: hyperventilation
signs/symptoms: dizziness, syncope
What is respiratory acidosis?
pH = decrease
PaCO2 = increase
HCO3 = WNL
causes: hypoventilation
signs/symptoms:
Early: anxiety, restlessness, dyspnea, headache
Late: confusion, somnolence, coma
What do you do to detect respiratory conditions:
First: examine pH value; if HIGH (above 7.45), ALKALOSIS is present
THEN: examine CO2 LEVELS, If below 35 mmHg, RESPIRATORY ALKALOSIS present
IF: pH was low (below 7.35) and CO2 levels are High (above 45 mm Hg),
RESPIRATORY ACIDOSIS is present
What do you do to detect metabolic conditions:
FIRST: examine pH values——High pH (above 7.45)
SECOND: examine CO2 levels (assumed to be normal)
THIRD: examine bicarb levels—–high bicarbonate (above 24 mmol/L)
Condition: METABOLIC ALKALOSIS
What is chronic respiratory acidosis?
pH <7.35
CO2 retention
PaCO2 >45 mmHg
HCO3 >28 mmol/L (compensating)
What are the possible causes of chronic respiratory acidosis?
hypoventilation due to pulmonary, cardiac, musculoskeletal, or neuromuscular disease
CNS depression from medication = possibly slows RR and tidal volume
What is chronic respiratory alkalosis?
pH >7.45
Excess CO2 excretion
PaCO2 <35 mmHg
HCO3 <24 mmol/L (compensating)
What are the possible causes of chronic respiratory alkalosis?
hyperventilation due to anxiety, pain, or improper ventilator settings
respiratory stimulation caused by drugs, disease, hypoxia, fever, or high room temperature
Metabolic acidosis findings:
pH <7.35
PaCO2 = 35mmHg
HCO3 <24 mmol/L
Metabolic acidosis possible causes:
HCO3 depletion due to renal disease, diarrhea, or small-bowel fistulas
hepatic disease results in excessive production of organic acids
endocrine disorders = diabetes mellitus
Metabolic alkalosis findings:
pH >7.45
PaCO2 = 45mmHg
HCO3 >28 mmol/L
Metabolic alkalosis possible causes:
Inadequate excretion of acids due to renal disease
Loss of hydrochloric acid from prolonged vomiting or gastric suctioning
Loss of potassium due to increased renal excretion
Steroid overdose
Excessive alkali ingestion
Respiratory Acidosis signs and symptoms =
hypercapnia (increased CO2)
hypoventilation
headache
visual disturb
confusion
coma/drowsiness
hyperalkemia
Metabolic Acidosis signs and symptoms =
bicarbonate deficit
hyperventilation
headache
mental dullness
deep respiration
coma/stupor
cardiac arrhythmias
What is alveolar hyperventilation?
leads to a PaCO2 less than normal
ratio with bicarbonate increases = blood pH increases = respiratory alkalosis
bicarbonate/CO2
What is alveolar hypoventilation?
leads to a PaCO2 greater than normal
ratio with bicarbonate decreases = blood pH decreases = respiratory acidosis
What is it called when a patient’s PaCO2 is > 50mmHg ?
Ventilation Failure = alveoli unable to remove CO2
Pulmonary Assessment: ABG: PaO2
75 and 100 mm Hg at sea level = As altitudes increase, normal values decrease
Air that we breath in is approximately 21% Oxygen
Total pressure of all of the gases you breathe = oxygen, nitrogen, carbon dioxide
Oxygenation status is determined by PaO2 levels:
80 – 100 mmHg - normal
between 60-80mmHg-mildly hypoxemic
between 40-60mmHg- moderate hypoxemic
under 40mmHg- severe hypoxemic
Hypoxemic Respiratory Failure: Type I
PaO2 <60 mmHg (decrease)
Hypoventilation (PaCO2 increases)
V/Q mismatch
Diffusion limitation
Pneumonia, COPD, atelectasis/lobar collapse, ARDS Intrapulmonary shunt = fluid filled alveoli that are perfused but not ventilated
What is the most common form of respiratory failure?
Hypoxemic Respiratory Failure: Type I
Hypercapnic Respiratory Failure: Type II
PaCO2 >50mmHg (increase)
Hyperventilation to compensate for high CO2
Compensation = Renal response, takes days to weeks
What causes Hypercapnic Respiratory Failure: Type II ?
Respiratory Center (medulla) dysfunction = drug overdose, CVA, tumor
Neuromuscular Disorders = SCI, Guillain-Barre, ALS, MD
Chest Wall/Pleural Diseases = Kyphosis, scoliosis, pneumothorax, massive pleural effusion
Upper Airway Obstruction = Tumor, foreign body, laryngeal edema
Respiratory Failure: Clinical Manifestations
Dyspnea –secondary to hypercapnia and hypoxemia
Altered breathing pattern
Cyanosis –poorly oxygenated hemoglobin
Circulatory changes –tachycardia, hypertension, or hypotension
Mental status changes –confusion, somnolence, convulsions, coma
Adventitious or absent lung sounds
Treatment of Respiratory Failure
Hypoxemia can cause death
Treat underlying cause = hypoxemia = hypoxia
Medical Management = Pharmacologic
PT Management = breathing strategies, strengthening, pacing
Supplemental oxygen : amount primarily determined by PaO2 and/or PaCO2
When does tissue hypoxia occur?
Pa02 <38mmHg or Sa02< 70%
Need to Increase to minimum levels of: Pa02>60mmHg and Sa02>87%02
What is SAO2?
measurement of oxygen saturation in arterial blood
measured by blood gas analysis
measured in peripheral blood taken from an artery through puncturing
measures the oxygen saturation of both functional and non-functional hemoglobin
important ot determine anemic conditions
What is SPO2?
oxygen saturation in the arterial blood measured as a pulse oximeter
measured by the pulse oximetry
noninvasive method - uses a transmissive pulse oximeter
measures the oxygen saturation of only functional hemoglobin
important in surgery and post-anesthetic care units, neonatal care and NICU, emergency care, noninvasive transcutaneous pacing
