Intro to Respiratory Care Exam 2

ATPS to STPD

-Example: convert 2L at 770 torr (ATPS)

•Factor = 0.9770

• STPD = 2 x .977 = 1.953 L

Gram molecular weight (gmw)

the mass of a substance equal to its molecular weight in grams

ex. Gmw of CO2 -> C + O + O ->

-12 + 16 + 16 = 44 gm = 1 mole

Solids

have a high degree of internal order; their atoms have a strong mutual attractive force (definite shape and volume)

Liquids

atoms exhibit less degree of mutual attraction compared with solids ( no shape)

Kinetic Energy

•Energy of motion

•The molecules of a gas are in constant, random motion

-very high velocity

-individual molecules collide with

•other molecules

•the walls of any container

Kelvin scales

-273 degrees C or -460 degrees F

K = - 273 degrees C

C = + 273 degrees K

Condensation

gas becomes a liquid and heat is given back to the surroundings

Melting

change from the solid to liquid state

Laplace's law

aw- pressure varies directly with the surface tension of the liquid and inversely with its radius

P = 2T/r

As a gas is compressed

increase collisions - increase temp

gas heated

Avogadro's Law

equal volumes of gases at the same temperature and pressure contain equal numbers of molecules

V1/n1=V2/n2 (direct)

Avogadro's Number

The ideal molar volume of any gas is 22.4 L

•6.023 x 10^23

-atoms, molecules or ions = 1 mole

-1 gmw of a substance = 1 mole

-32 gm O2 = 1 mole = 6.023 x 1023 mole.

•Ideal gas at STPD (0 oC; PB = 760 mmHg)

molar volume

Density of Gases

•D = mass/volume

-reported at STPD (0 oC; PB = 760 mmHg)

-grams/liter

-1 mole at STPD = 22.4 L

-1 mole = 1 gmw

Dalton's Law of Partial Pressure

The total pressure exerted by a gas mixture is the sum of the separate partial pressure of each gas in the mixture or

-PT = P1 + P2 + P3 + P4 + ......... + PN

Normal Barometric Pressure

•1 atmosphere

•760 mm Hg

•760 torr

•76 cm Hg

•29.9 in Hg

•33.9 ft H2O

•1034 gm/cm2

14.7 lb/in2 or psi

•1.014 x 106 dynes/cm2

•1014 milibars

Hypobarism

Atmospheric pressure below 1 atm (negative)

Space

-PB = 760 mm Hg

•PO2 = 760 x .2095 = 159 mm Hg

Hyperbarism

Atmospheric pressure above 1 atm (positive)

Undersea

-At 25,000 feet PB = 282 mm Hg

•PO2 = 282 x .2095 = 59 mm Hg

Hypobarism & Hyperbarism

•66 ft = 3 atmospheres

-2 due to water

-1 due to air above the water

-3 total

-PO2 = .2095 x 2280 = 477.7 mm Hg

Gay-Lussac's Law

if vol. and mass remain unchanged, the pressure exerted by a gas will vary directly with the absolute temperature of the gas.

P1 = P2 OR P/T = k

T1 T2

Charles' Law example

•Given V1 = 100ml, T1 = 25C and T2 = 37C, find V2.

–100/(25+273) = V2/(37+273)

–V2 = 104 ml

Graham's Law

law of diffusion states that the rate of gas diffusion is inversely proportional to the square root of its gram molecular weight.

Laminar flow

a smooth pattern of flow

Poiseuille's law

-predicts pressure required to produce a given flow

-Change in P = 8nlV̇ /πr4

Factors affecting communication between the RT and the patient include the following

Sensory and emotional factors

Environmental factors

Verbal and nonverbal components of the communication process

Cultural and other internal values, beliefs, feelings, habits, and preoccupations of both the RT and the patient

Interview in personal space

2-4 feet

Orthopnea

difficulty breathing when lying down

(ability to breathe only in an upright position)

Common in patients with CHF, mitral valve disease, and superior vena cava syndrome

Orthodeoxia

oxygen desaturation on assuming an upright position, (accompanies platypnea)

RT should try to categorize each sensation according to a particular aspect of breathing

inspiration, expiration, respiratory drive, or lung volume

Cough characteristics include:

Dry or loose, productive or nonproductive, acute or chronic, and whether it occurs more frequently at particular times (e.g., day or night)

A chronic cough is one lasting 8 weeks or longer

Sputum

Mucus from lower airways but is expectorated through mouth

(material expelled from the lungs by coughing, spitting)

Massive hemoptysis

More than 300 ml of blood expectorated over 24 hours

Common causes: bronchiectasis, lung abscess, and acute or chronic tuberculosis

Hematemesis

vomiting blood from the gastrointestinal tract

Pleuritic chest pain

located laterally or posteriorly

Sharp, and increases with deep breathing

(pneumonia and pulmonary embolism)

Non-pleuritic chest pain

located in center of chest and may radiate to shoulder or arm; it is not affected by breathing

-Often caused by angina, gastroesophageal reflux, esophageal spasm, chest wall pain, and gall bladder disease

The first priority of the RT reviewing the medical record is

is to ensure that all respiratory care procedures are supported by a physician order that is current, clearly written, and complete

Then review the patient's medical record by reading about current medical problems.

Physical Examination

Essential for evaluating patient's problem and determining ongoing effects of therapy

Normal Body Temperature

98.6 F (37 C)

Hypothermia

low body temperature

Most common cause is prolonged exposure to cold

Less common causes include head injury or stroke, decreased thyroid activity, and overwhelming infection

How to measure body temperature

mouth, axilla, ear, or rectum

Rectal temp: closest to core body temperature

Normal adult pulse rate

60-100 beats per minute

Tachycardia

Fast Heat Rate

more than 100 beats/min

Treat causes first

Common causes are exercise, fear, anxiety, low blood pressure, anemia, fever, hypoxemia, hypercapnia, and certain medications

Pulsus paradoxus

a significant decrease in pulse strength (>10 mm Hg) during spontaneous inspiration

Common in patients with acute obstructive pulmonary disease, especially patients experiencing an asthma attack

Systolic pressure

the peak force exerted in the major arteries during contraction of the left ventricle

Systolic: 90 to 140 mm Hg

Nasal flaring indicates

respiratory distress—increased WOB

often seen in infants

Pursed-lip breathing

seen in patients with COPD to prevent collapse of small airways

Deep inspiration followed by prolonged expiration through pursed lips.

Thoracic configuration

-The anteroposterior (AP) diameter of the average adult thorax is less than the transverse diameter

-The abnormal increase in AP diameter is called barrel chest

Associated with emphysema

Kyphosis (hunchback)

Spinal deformity in which the spine has an abnormal AP curvature

Thoracic expansion

The expansion of the chest wall palpated when the person takes a deep breath; should be bilateral and symmetric

•Reduced expansion commonly is seen in neuromuscular disorders and COPD

•Unilateral reduction in chest expansion occurs with respiratory diseases that reduce the expansion of one lung or a major part of one lung

Common causes of an increase in WOB include

-Narrowed airways (e.g., COPD, asthma)

-"Stiff lungs" (e.g., acute respiratory distress syndrome, cardiogenic pulmonary edema)

-A stiff chest wall (e.g., ascites, anasarca, pleural effusions)

Retraction

inward sinking of the chest wall during inspiration

Intercostal, supraclavicular, or subcostal retractions

Occurs when inspiratory muscle contractions generate very large negative intrathoracic pressures

Biot respiration

Clustering of rapid, shallow breaths coupled with regular or irregular periods of apnea

Causes: Damage to medulla or pons caused by stroke or trauma; severe intracranial hypertension

Cheyne-Stokes respiration

Irregular type of breathing; breaths increase and decrease in depth and rate with periods of apnea; variant of "periodic breathing

Causes: Most often caused by severe damage to bilateral cerebral hemispheres and basal ganglia (usually infarction); also seen in patients with CHF owing to increased circulation time and in various forms of encephalopathy

Paradoxical breathing

A form of abnormal breathing that is common in tetraplegia where the abdomen rises and the chest is pulled inward during inspiration. On expiration the abdomen falls and the chest expands (abdominal or chest paradox)

Chest paradox

Part or all of the chest wall moves in with inhalation and out with exhalation

•Causes:—Typically observed in chest trauma with multiple rib or sternal fractures; also found in patients with high spinal cord injury with paralysis of intercostal muscles

Palpation

art of touching the chest wall to evaluate underlying structure and function

Bronchial breath sounds

Abnormal if heard over peripheral lung regions

Replacing normal vesicular sounds when lung tissue density increases

Wheezes

Consistent with airway obstruction

Monophonic wheezing indicates one airway is affected

Polyphonic wheezing indicates many airways are involved

(continuous high-pitched whistling sounds produced during breathing)

Stridor

Upper airway compromised

Chronic stridor—laryngomalacia

Acute stridor—croup

Inspiratory stridor—narrowing above glottis

Expiratory stridor—narrowing of lower trachea

Coarse crackles

excessive secretions

Airflow moves secretions or fluid in airways

Usually clears when patient coughs or upper airway is suctioned

Asthma

heterogeneous disease, usually characterized by chronic airway inflammation.

defined by the history of respiratory symptoms such as wheeze, shortness of breath, chest tightness and cough that vary over time and in intensity, together with variable expiratory airflow limitation.

Chronic airway obstruction caused by

viscous secretions is soon followed by colonization with pathogenic bacteria

•Chronic inflammation causes lung damage that ultimately advances to the stage of irreversible bronchiectasis and progressive respiratory failure

Maximal impulse

Left ventricular contraction is the most forceful and generates a palpable pulsation

PMI)- felt at 5th intercostal space, left midclavicular line

Cardiac Examination: S3

abnormal in adults and caused by rapid filling of stiff left ventricle

Cardiac murmurs are created by:

Backflow of blood through an incompetent valve

Forward flow of blood through a stenotic ("narrowed") valve

Rapid blood flow through a normal valve (as occurs with heavy exertion).

Murmurs in babies may suggest

cardiovascular abnormalities related to inadequate adjustment to extrauterine life

Digital cyanosis (acrocyanosis)

often sign of poor perfusion; hands and feet typically cool to touch in such cases

Acrocyanosis occurs frequently in newborns; usually disappears within 24 to 72 hrs after birth

Critical Test Value

A result significantly outside the reference range and represents a pathophysiologic condition

Leukocytosis (white blood cells)

WBC count above normal

common with infection, stress, & trauma

most often due to elevation of only 1 of 5 types of white blood cells

Degree of leukocytosis depends on severity of infection

Neutrophilia

Elevation of absolute value of neutrophils

Bands: Immature neutrophils

Segmented neutrophils (segs): mature neutrophils

When bands & segs are elevated in CBC, patient is likely experiencing more severe bacterial infection

Red blood cells (erythrocytes)

supply oxygen to the tissues

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Reduced RBC count is called anemia

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Anemia is due to either blood loss or reduced RBC production by bone marrow

˜

Anemia reduces oxygen-carrying capacity of blood

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Several types of anemia exist with different causes (dietary deficiencies, chronic inflammatory disease, hereditary)

Normal hemoglobin concentration

12-16 g/dL

Plays role of bonding with oxygen

RBCs with reduced hemoglobin are smaller than normal (microcytic anemia) & lack normal color (hypochromic anemia).

Potassium (K+) normal range

3.5-5.0 mEq/L

Chloride (Cl-) normal range

98-106 mEq/L

Hyperglycemia

high blood sugar

Often result of diabetes

Anion Gap

= Na - (Cl + HCO3)

or total CO2

Metabolic acidosis is caused by addition of non-volatile acids or loss of HCO3-

Determines if decrease in HCO3- is caused by disruption of normal anion balance or presence of abnormal acid anion

Anion gap normal range

between 8-16 mmol/L

Acid-Fast Testing

Identifies acid-fast bacterium

Mycobacterium tuberculosis

Steps:

Gram stain sputum sample

Acid wash sputum sample

If organism is resistant to decolorization, then it is classified as an acid-fast bacterium

Gases

weak molecular attractive forces; gas molecules exhibit rapid, random motion with frequent collisions (no definite shape or volume)

potential energy

•Energy of position

•Result of strong attractive forces between molecules

•Solids and liquids internal energy is mostly potential

(stored energy that results from the position or shape of an object)

Theoretical temperature

at which all molecular activity ceases.

-absolute zero- no kinetic activity

-basis for the Kelvin scales

Convert C to Kelvin

add 273

C+273=K

Convert K to C

subtract 273

K-273= C

Convert Fahrenheit to Celsius

(F - 32) / 1.8 = C

Convert Celsius to Fahrenheit

1.8 X C + 32 = F

The First law of thermodynamics

Energy cannot be created or destroyed

Conduction

transfers heat in solids by direct contact

Convection

-transfers heat in liquids and gases

(e.g., forced air heating in homes, heating in infant incubators

Radiation

occurs without direct contact between two substances

Evaporation

Heat is taken from the air to change liquid to gas

Melting point

the temperature at which melting occurs

solid to liquid

Freezing

change from the liquid to solid state

freeezing point

the temperature at which the substance freezes; same as its melting point

Boiling

heating a liquid to a temperature at which its vapor pressure equals atmospheric pressure

water vapor pressure

partial pressure due to water vapor

Absolute humidity

actual amount or weight of water vapor in a gas

Relative humidity

the ratio of its actual water vapor content to its saturated capacity at a given temperature

•%RH= content (absolute humidity) / saturated capacity x 100

Pressure of a liquid

-depends on the height times weight density (mmHg, cm H2O)

Buoyancy

-occurs because the pressure below a submerged object always exceeds the pressure above it.

Used to measure specific gravity of certain liquids

ability to float

Viscosity

a liquid's resistance to flow

-the force opposing a fluid's flow

•Blood has a viscosity five times greater than that of water

Cohesion

The attractive force between LIKE molecules

EX. Convex with mercury