pulmonary function tests, arterial blood gases and lab values

what are pulmonary function tests?

• used to diagnose lung disease

• non-invasive test that evaluates how well air moves in/out of lungs

• measures lung volumes, capacities, flow rates, and gas diffusion capacities

• results are compared to predictive norms based on gender, rage, age and height

what are PFTs classified as?

• normal

• obstructive

• restrictive

• combined

what is spirometry?

It measures how much air your lungs can hold and how fast you can blow that air out., nose clipped, breathe thru mouth

what is tidal volume?

the volume of gas inspired or expired in an unforced respiratory cycle.

what is tidal volume for females?

400 mL

what is tidal volume for males?

500mL

what is inspiratory reserve volume?

the maximum volume of gas that can be inspired during forced breathing in addition to tidal volume

what is expiratory reserve volume?

the maximum volume of gas that can be expired during forced breathing in addition to tidal volume

what is residual volume?

the volume of gas remaining in the lungs after a maximal expiration

if you have hyperinflated lungs (obstructed lung disease), is your RV increased or decreased?

RV is increased

if you have restricted lung disease, is your RV increased or decreased?

decreased RV

what is total lung capacity?

the total amount of gas in the lungs after a maximum inspiration

does your TLC increase or decrease with obstructed lung disease?

TLC increases

does your TLC increase or decrease with restricted lung disease?

decreased TLC

what is vital capacity?

the maximum amount of gas that can be expired after a maximum inspirationw

what is inspiratory capacity?

the maximum amount of gas that can be inspired after a normal tidal expiration

what is functional residual capacity?

the amount of gas remaining in the lungs after normal tidal volume

does functional residual capacity increase or decrease with obstructed lung disease?

FRC increases with obstructed lung disease

what is forced vital capacity?

maximal amount of air that can be forcefully blown out after a maximal inspiration

what is forced expiratory volume in 1 second?

maximal amount of air that can be exhaled in one second

what is FEV1/FVC?

the % of FVC that can be exhaled in 1 second

it indicated pulmonary airflow capacity

what is normal FEV1/FVC?

normal is 70-85%

what is obstructive lung disease?

FEV1/FVC is less than 70%

what is restrictive lung disease?

FEV1/FVC is normal or high

what are the pulmonary function test results for obstructive?

• increase RV and FRC

• decrease IRV

• Normal or Increased TLC

what are the pulmonary function test results for restrictive?

• decreased lung volumes

• decreased TLC

what are FVC, FEV1,FEV1/FVC and TLC for obstructive?

• decreased or normal FVC

• decreased FEV1

• decreased VEF1/FVC ration

• Normal or increased TLC

what are FVC, FEV1,FEV1/FVC and TLC for restrictive?

• decreased FVC

• decreased or normal FEV1

• normal VEF1/FVC ratio

• decreased TLC

what is maximal inspiratory pressure (MIP)?

• measures the peak pressure generated during inspiration

what happens with weak muscles of inspiration?

hard to take a breath

what is maximal expiratory pressure (MEP)?

measures the peak pressure generated during expiration

what happens if you have weak expiratory muscles?

• hard to cough

• hard to clear secretions

• hard to yell, shout, sing

what is maximum voluntary ventilation?

• tests ventilatory capacity by having the person breath rapidly and deeply for 15 seconds

• low values can indicate respiratory muscle weakness, airway obstruction or poor effort

what is DLCO?

• diffusing capacity of the lungs for carbon monoxide

• it measures the lung’s ability to transfer gas from inhaled air to the blood (lung diffusion)

what are low values of DLCO?

low values are (less than 75% of predicted), and it indicates that the oxygen is not diffusions into the blood efficiently

what are possible diseases that can cause a low DLCO?

• COPD

• ILD

• anemia

what are arterial blood gases?

• measures a patient’s acid-base balance, alveolar ventilation and oxygenation status

• normally the body maintains its acid-base balance via excretion of acids

  • CO2 via lungs: quicker

  • other acids via kidney: slower

• provides info about effectiveness of the respiratory system oxygenating the blood and removing CO2

• arterial samples are obtained from a needle puncture or an indwelling catheter (a-line)

what is the normal pH ABG for lungs?

7.35-7.45

what is the normal ABG value for PaCO2?

35-45 mmHg

what os the normal ABG value for HCO3?

22-26 or 28 mEq/L

what are the normal ABG values for PaO2?

80-100 mmHg

what are the normal ABG values for SaO2?

95-100%

what is acidosis?

when the pH is less than 7.35

what is alkalosis?

when the pH is more than 7.45

what is hypocapnia?

when the PaCO2 is under 35 mmHG

what is hypercapnia?

when the PaCO2 is above 45 mmHg

what is hypoxemia?

when the PaO2 is less than 80 mmHgw

what is hyperoxemia?

when the PaO2 is over 100 mmHg

what is respiratory acidosis?

increase of PaCo2, decrease in pH

what is respiratory alkalosis?

decrease in PaCO2 and increase in pH

what is metabolic acidosis?

increase in HCO3 and decrease in pH

what is metabolic alkalosis?

increase in HCO3 and increase in pH

what is opposite direction?

respiratory

what is same direction?

metabolic

what are causes of respiratory acidosis?

• failure of ventilation (alveolar hypoventilation)

• COPD exacerbation: cannot get air out=CO2 retention

• CNS depression - overdose on sedative, opioids or alcohol

• increase secretions = CO2 retention

• hypoventilation due to pain or muscle weakness

• cardiopulmonary arrest

what are signs and symptoms of respiratory acidosis?

• anxiety, confusion, headache

• fatigue/lethargy

• tachypnea

• coma, seizure

what are causes of respiratory alkalosis?

• hyperventilation

• anxiety/panic, fever, pain or mechanical ventilator

• hypoxia

• pulmonary fibrosis (restrictive lung disease)

• high altitude

• pulmonary embolism

• brain injury or tumor

whata re signs and symptoms of respiratory alkalosis?

• lightheadedness/dizziness

• confusion

• numbness in hands/feet

• muscle spasm/ache

• seizures and cardiac dysrhythmias

whata re causes of metabolic acidosis?

• diabetic ketoacidosis

• lactic acidosis from tissue hypoxia

• intoxication of organic acids

• renal failure

what are signs and symptoms of metabolic acidosis?

• deep/rapid breathing/kussmaul respirations (hyperventilation - lungs trying to compensate by getting rid of CO2 to raise pH

• confusion/dizziness

• fatigue

• n/v

• tachycardiac

what are the causes of metabolic alkalosis?

• profuse vomiting

• diuretics or corticosteroid medications

• drugs, ng tube, significant fluid loss

what are signs and symptoms of metabolic alkalosis?

• hypoventilation - shallow breathing causes CO2 retention which can help lower the pH

• confusion, lethargy, dizziness

• numbness/tingling in feet/hands

• muscle spasms/aches

• convulsions, seizures and cardiac dysrhythmias

what are normal levels of hemoglobin in males?

14-18

what are normal levels of hemoglobin in females?

12-16

what are the normal levels of hematocrit in men?

42-52% (3x whatever the hemoglobin is)

what are the normal levels of hematocrit in females?

37-47%, 3x whatever the hemoglobin is

whjat is the cut off for hemoglobin?

8! need medical clearance

what is normal WBC count?

5000-10000

when are WBC high?

bodies response to infection

when are WBC low?

low w cancer

what are normal platelets?

150,000-400,000

what are low platelits at risk for

bleedingw

what are high platelets at risk for?

blood clots