Midterm Flashcards
absolute shunt
The sum of anatomic shunt and capillary shunt. It is refractory to oxygen therapy.
accessory muscles
Muscles not normally used during quiet breathing that are available for assisting either inspiration or expiration during times of increased work of breathing.
acids
Substances that dissociate or lose ions.
acute respiratory distress syndrome (ARDS)
A type of respiratory failure caused by diffuse injury to the alveolar-capillary membrane, resulting in noncardiogenic pulmonary edema.
air trapping
The abnormal retention of air in the lungs on exhalation.
anatomic shunt
Movement of blood from the right heart and back into the left heart without coming into contact with alveoli.
base excess
A measure of the amount of buffer required to return the blood to a normal pH state. It is used in reference to metabolic acid-base states. A person can develop a base excess (metabolic alkalosis) or a base deficit (metabolic acidosis).
bases
Substances capable of accepting ions.
buffer
A substance that reacts with acids and bases to maintain a neutral environment of stable pH.
capillary shunt
Normal flow of pulmonary blood past completely unventilated alveoli.
capnogram
Graphic representation of carbon dioxide levels during respiration.
capnometry
Measurement of carbon dioxide in expired gas.
carina
The junction of the Y formed by the right and left mainstem bronchi in the lungs.
compensated
A state in which the pH is within normal limits with the acid-base imbalance being neutralized but not corrected.
compliance (CL)
Measurement of the relative ease with which an organ can expand; reflects relative stiffness of the organ; in the lungs, it is the amount of force required to expand the lungs; measured in mL/cm H2O; normal is 50 to 100 mL/cm H2O.
cor pulmonale
Right ventricular hypertrophy and dilation secondary to pulmonary disease, resulting in pulmonary hypertension.
corrected
A state in which all acid-base parameters have returned to normal ranges after a state of acid-base imbalance.
crackles (rales)
Adventitious breath sounds associated with fluid or secretions or both in small airways or alveoli.
diffusion
Movement of gases across a pressure gradient from an area of high concentration to one of low concentration.
dyspnea
Subjective sensation of difficulty breathing.
end-tidal carbon dioxide (PETCO2 or ETCO2)
Concentration of carbon dioxide at the end of exhalation.
external respiration
Movement of gases across the alveolarcapillary membrane.
forced expiratory volume (FEV)
Measure of how rapidly a person can forcefully exhale air after a maximal inhalation; a measurement of dynamic lung function.
hemoptysis
Expectoration of bloody sputum.
hypercapnia
Abnormally high level of carbon dioxide in the blood.
internal respiration
Movement of gases across the systemic capillary-cell membrane in the tissues.
minute ventilation (VE)
The total volume of expired air in one minute.
nonvolatile acids
Metabolic acids that cannot be converted to a gas, requiring excretion through the kidneys.
orthopnea
Difficulty breathing while laying down, relieved in the upright position.
oxyhemoglobin dissociation curve
A graphic representation of the relationship between oxygen saturation of hemoglobin (SaO2) and the partial pressure of oxygen (PaO2) in the plasma.
PaO2
The partial pressure of oxygen as it exists in the arterial blood; normal range is 75 to 100 mm Hg.
parietal pleura
The moist membrane that adheres to the thoracic walls, diaphragm, and mediastinum.
paroxysmal nocturnal dyspnea (PND)
A symptom usually associated with transient pulmonary edema secondary to heart failure; patient awakens from sleep with severe orthopnea.
partial pressure
Pressure each gas exerts in a total volume of gases.
partially compensated
A state in which the pH is abnormal but the body buffers and regulatory mechanisms have started to respond to the imbalance.
perfusion
The pumping or flow of blood into tissues and organs.
pH
Represents free hydrogen ion concentration.
pleural rub
Adventitious breath sound caused by inflammation of the pleural membrane.
pleurisy (pleuritis)
Pain caused by inflammation of the parietal pleura.
positive end-expiratory pressure (PEEP)
The application of positive pressure to the airway at the end of expiration such that the airway pressure never returns to ambient.
pressure gradient
Difference between the partial pressures of a gas; influences rate of diffusion.
pulmonary shunt
The percentage of cardiac output that flows from the right heart and back into the left heart without undergoing pulmonary gas exchange or not achieving normal levels of PaO2 because of abnormal alveolar functioning.
pulmonary vascular resistance (PVR)
Afterload of the right ventricle; the resistance the right ventricle must overcome to open the pulmonic valve and eject the stroke volume into the pulmonary artery.
pulse oximetry
Noninvasive technique for monitoring arterial capillary hemoglobin saturation.
respiration
The process by which the body’s cells are supplied with oxygen and carbon dioxide is eliminated from the body; also refers to breathing, the movement of air in and out of the lungs.
rhonchi
Adventitious breath sounds associated with an accumulation of fluid or secretions in the larger airways.
shuntlike effect
Effect created by an excess of perfusion in relation to alveolar ventilation.
stridor
A type of wheeze heard loudest over the neck suggesting obstruction of the trachea or larynx.
surfactant
A lipoprotein produced by type II alveolar cells that reduces the surface tension of the alveolar fluid lining.
tidal volume (TV or VT)
The volume of air moved in and out of the lungs during one normal breath. It is also an important setting on a mechanical ventilator - if set too high the patient is hyperventilated and if set too low the patient is hypoventilated.
total lung capacity (TLC)
The amount of gas present in the lungs after maximal inspiration.
true shunt
Flow of blood from the right heart, through the lungs, and on into the left heart without taking part in alveolar-capillary diffusion or oxygen exchange.
uncompensated
An acid-base state in which the pH is abnormal because other buffer and regulatory mechanisms have not begun to correct the imbalance.
V/Q ratio
A ratio expressing the relationship of ventilation to perfusion.
venous admixture
The effect that a physiologic shunt has on the oxygen content of the blood as it drains into the left heart.
ventilation
The gross movement of air in and out of the lungs; airflow between the atmosphere and alveoli.
visceral pleura
The moist membrane that adheres to the lung parenchyma and is adjacent to the parietal pleura.
vital capacity (VC)
The volume of air that can be exhaled after maximum inhalation; an indication of respiratory muscle strength; normal is 65 to 75 mL/kg.
volatile acids
Acids that can convert to a gas form for excretion.
wheeze
Adventitious breath sound caused by air passing through constricted airways.
spiral CT scan
A specialized computerized axial tomography scan (CT scan) that continuously moves the patient through the scan quickly; provides greater visualization of blood vessels.
status asthmaticus
A life-threatening emergency of acute airway obstruction that does not respond to usual therapy.
surfactant
A lipoprotein produced by type II alveolar cells that reduces the surface tension of the alveolar fluid lining.
tidal volume (TV or VT)
The volume of air moved in and out of the lungs during one normal breath. It is also an important setting on a mechanical ventilator - if set too high the patient is hyperventilated and if set too low the patient is hypoventilated.
total lung capacity (TLC)
The amount of gas present in the lungs after maximal inspiration.
V/Q ratio
A ratio expressing the relationship of ventilation to perfusion.
ventilatory failure
A condition caused by alveolar hypoventilation; clinically, it is called acute respiratory acidosis.
wedge resection
Surgical procedure that removes a wedge-shaped section of the peripheral portion of the lung.
afterload
The resistance against which the ventricle pumps blood.
apical-radial pulse deficit
The difference between the apical and radial pulse rates, which reflects the number of heartbeats too weak to be transmitted to the periphery.
atrial gallop
Abnormal S4 heart sound caused by atrial contraction.
B-type natriuretic peptide
(BNP) Hormone released from the ventricles in response to increased preload; causes urinary excretion of sodium and diuresis. Its action results in reduced preload.
body surface area (BSA)
A measure of overall body size using both height and weight in its calculation.
C-reactive protein (CRP)
Peptide released by the liver in response to inflammation, infection, and tissue damage; downstream marker for inflammation now considered a major risk factor for heart disease.
cardiac index (CI)
Cardiac output divided by body surface area.
cardiac output (CO)
The amount of blood pumped by the heart each minute.
contractility
The ability of a muscle to shorten when stimulated; in particular, the force of myocardial contraction.
ejection fraction (EF)
The amount of blood ejected from the left ventricle per each heartbeat; normal is above 50 percent.
hyperlipidemia
A condition manifested by high levels of lipids in the blood.
inotrope
Factor that influences myocardial contractility; a positive inotrope increases myocardial contractility; a negative inotrope decreased myocardial contractility.
palpitations
Subjective feeling of heart rhythm abnormalities; perceived as a “skipping” or “thumping”; related to premature cardiac beats.
preload
The degree of stretch in myocardial fibers at the end of diastole.
pulse pressure
Difference between diastolic and systolic pulse pressure.
pulsus alternans
Alternating weak and strong pulses.
stroke volume (SV)
The volume of blood pumped with each heartbeat.
summation gallop
S3 and S4 heart sounds are present; indicative of severe heart failure.
syncope
A temporary loss of consciousness, followed by a spontaneous and complete recovery.
troponin
A protein found in cardiac muscle; when present in the blood, it is used as a marker of myocardial cell death.
ventricular gallop
S3 heart sound caused by decreased ventricular compliance.
aortic regurgitation (AR)
Aortic valve insufficiency that allows blood to flow back into the left ventricle from the aorta during diastole.
aortic stenosis (AS)
A narrowing of the aortic valve orifice so that blood flow is obstructed from the left ventricle into the aorta during systole.
cardiomyopathy
End-stage heart failure (class IV); the patient has symptoms of HF at rest and cannot perform activities of daily living.
constrictive cardiomyopathy
Condition associated with normal left ventricular size and a slightly depressed ejection fraction with a marked decrease in cardiac muscle compliance.
diastolic dysfunction
Heart failure characterized by impairment of ventricular relaxation.
dilated cardiomyopathy
Condition associated with left ventricular dilation and decreased ejection fraction.
drug allergy
Refers to an immune-based hypersensitivity reaction (for example, rash, or hypotension).
drug side effect
Refers to a predictable or expected undesirable effect of a drug.
echocardiogram
Noninvasive technology that allows visualization of the valves; their movement; as well as the size, thickness, and function of the aorta and ventricles.
heart failure (HF)
Clinical syndrome that can result from structural or functional cardiac disorders that decrease the ability of the ventricle to fill or eject.
hypertrophic cardiomyopathy
Condition associated with left ventricular hypertrophy that decreases the ability of the chamber to relax (diastolic dysfunction).
infective endocarditis (IE)
A disease caused by microbial infection of the endothelial lining of the heart, usually presenting with vegetations on a heart valve.
mitral regurgitation (MR)
Incompetent mitral valve allows blood to flow back into the left atrium during systole because the mitral valve does not fully close.
mitral stenosis (MS)
A narrowing of the mitral valve orifice so that blood flow is obstructed from the left atrium into the left ventricle during diastole.
mitral valve prolapse
A type of mitral valve insufficiency that occurs when one or both of the mitral valve cusps flow into the atria during ventricular systole.
orthopnea
Difficulty breathing while laying down, relieved in the upright position.
prehypertension
Defined as systolic blood pressure of 139 to 150 mm Hg and diastolic blood pressure of 80 to 89 mm Hg.
regurgitation
Backward blood flow through the chambers of the heart.