Early Repolarization-Endotracheal Tube

early repolarization a normal variant of myocardial repolarization in which the ST segment is elevated or depressed 1 to 3 mm above or below the baseline, respectively. Most commonly elevated in leads I, II, and aVF and the precordial leads V2-V6

Eaton-Lambert disorder rare myasthenic-like disorder resulting from a reduction of transmitter release from presynaptic terminals; commonly associated with small cell carcinoma of the lung; limb and girdle muscles predominantly are involved.

ECC02R abbreviation for extracorporeal carbon dioxide removal

ECG abbreviation for electrocardiogram.

ECG artifacts See Artifacts.

ECG calipers a device used in determining the heart rate and rhythm and measuring the various intervals and segments in an ECG tracing.

ECG grid the grid on the ECG paper is formed by dark and light horizontal and vertical lines. It is used to measure the time in seconds (sec) and distance in millimeters (mm) along the horizontal lines and voltage (amplitude) in millimeters (mm) along the vertical lines. The dark vertical lines are 0.20 second (5 mm) apart; the light vertical lines, 0.04 second (1 mm) apart. The dark horizontal lines are 5 mm apart; the light horizontal lines, 1 mm apart. A large square is 5 X 5 mm; a small square, 1 X 1 mm.

ECG lead one of twelve ECG leads that measure the differ­ence in electrical potential generated by the heart, obtained by using a positive and a negative electrode-the positive electrode attached to an extremity or the anterior chest wall and the negative electrode to an extremity or a central terminal. Includes leads I, II, III, aVR, aVL, aVF, and V1 through V6

ECG lead V'R a precordial lead obtained by placing the positive electrode in the right midclavicular line in the right fifth intercostal space. Used primarily to rule out a right ventricular myocardial infarction after the initial finding of an inferior myocardial infarction.

echocardiogram, echocardiography, echocardiographic an ultrasonographic study of the motion of the walls or structures of the heart  

eclampsia the gravest form of toxemia of pregnancy, characterized by grand mal convulsion, coma, hypertension, proteinuria, and edema

ECMO abbreviation for extracorporeal membrane oxygenation; the procedure whereby venous blood is pumped outside the body to a heart-lung machine for oxygenation and returned to the body through an artery

ectopic out of normal position  

ectopic atrial tachycardia an atrial tachycardia that originates in a single atrial ectopic pacemaker site, characterized by P' waves that are usually identical.

ectopic beats premature beats originating in ectopic pacemakers in the atria, AV junction, and ventricles (e.g., premature atrial contractions (PAC's), premature junctional contractions (PJC's), and premature ventricular contractions (PVC's).

ectopic foci an area of the heart that produces abnormal beats. Ectopic foci may occur in both healthy and diseased hearts and are usually associated with irritation of a small area of myocardial tissue. They are produced in association with myocardial ischemia, drug (catecholamine) effects, emotional stress, and stimulation by foreign objects, including pacemaker catheters.

ectopic focus a pacemaker other than the SA node.

ectopic pacemakers abnormal pacemakers in the atria, AV junction, bundle branches, Purkinje network, and ventricular myocardium.

ectopic P wave (P' wave) a P wave produced by the depolarization of the atria in an abnormal direction, initiated by an electrical impulse arising in an ectopic pacemaker in the atria, AV junction, or ventricles. The ectopic P wave may be either positive (upright) or negative (inverted) in lead II and may precede or follow the QRS complex.

ectopic rhythms arrhythmias originating in ectopic pacemakers in the atria, AV junction, and ventricles.

• Atrial. Wandering atrial pacemaker (WAP), premature atrial contractions (PAC's), atrial tachycardia (ectopic atrial tachycardia, multifocal atrial tachycardia), atrial flutter, atrial fibrillation

• Junctional. Premature junctional contractions (PJC's), non paroxysmal junctional tachycardia (accelerated junctional rhythm, junctional tachycardia), paroxysmal supraventricular tachycardia (PSVT)

• Ventricular. Accelerated idioventricular rhythm (AIVR) , premature ventricular contractions (PVC's), ventricular tachycardia (VT), ventricular fibrillation (VF)

ectopic tachycardias abnormal rhythms originating in ectopic pacemakers having a rate of over 100 beats per minute, such as atrial tachycardia (ectopic atrial tachycardia, multi focal atrial tachycardia), atrial flutter, atrial fibrillation, junctional tachycardia, paroxysmal supraventricular tachycardia (PSVT), and ventricular tachycardia (VT).

ectopic ventricular arrhythmias abnormal rhythms originating in ectopic pacemakers in the ventricles, such as accelerated idioventricular rhythm (AIVR), premature ventricular contractions (PVC's), ventricular tachycardia, and ventricular fibrillation.

ectopy a condition signifying the presence of ectopic beats and rhythms (e.g., ventricular ectopy).

echocardiography diagnostic/assessment tool using ultrasound to examine the heart structures and function by transmission of high-frequency ultrasound waves through the chest and calibrating the velocity of sound waves in the medium under examination.

edema a local or generalized condition in which the body tissues contain an excessive amount of extracellular fluid.

effacement the thinning or obliteration of the cervix during labor

efferent carrying away from a central organ or section.

efferent nerves nerves that carry impulses from the brain or spinal cord to the periphery.

efficacy maximum achievable effect a drug is able to produce, regardless of concentration.

effusion the escape of fluid from blood vessels because of rupture or seepage, usually into a body cavity

egophony auscultation sound typical in consolidation of lung tissue, meaning that the normally aerated tissue has been filled with fluid, mucus, pus, or cellular debris; in egophony, e sounds like a.

EGTA abbreviation for the esophageal gastric tube airway; a modification of the esophageal obturator airway (EOA), which includes a gastric tube that can be extended beyond the distal tip into the stomach in order to remove air or gastric contents

Einthoven's equilateral triangle an equilateral triangle depicted in the frontal plane using the lead axes of the three limb leads as the sides with the heart and its zero reference point in the center.

Einthoven's law the sum of the electrical currents recorded in leads I and III equals the sum of the electrical currents recorded in lead II.

EIP abbreviation for end-inspiratory pause; a technique whereby a specific inflation volume is momentarily held at the end of inspiration during mechanical ventilation, for either therapeutic or diagnostic purposes

ejection fraction percentage of blood pumped from the ventricle during a single cardiac contraction; normal left ventricular ejection fraction is greater than 50%.

ejection volume the ratio of cardiac stroke volume to end­diastolic volume

elastance ratio of pressure change to volume change (that is, the reciprocal of compliance).

elastic load pressure necessary to overcome the elastance (or compliance) of the respiratory system.

elastin a protein that forms the principal substance of yellow elastic tissue fibers

electric potentiometer a device that allows the operator to vary the electrical current in a circuit.

electric current the flow of electricity along a conductor in a closed circuit.

electrical activity of the heart the electric current generated by the depolarization and repolarization of the atria and ventricles, which can be graphically displayed on the ECG.

electrical alternans periodic alternation in the size of the QRS complexes between normal and small, coincident with respiration; typically present in cardiac tamponade.

electrical analyzer a type of gas analyzer that detects changes in electrical current in response to varying gas concentrations.

electrical axis and vector a graphic presentation, using an arrow, of the electric current generated by the depolarization and repolarization of the atria and ventricles.

electrical conduction system of the heart includes the sinoatrial (SA) node, internodal atrial conduction tracts, interatrial conduction tract (Bachmann's bundle), atrioventricular (AV) node, bundle of His, right and left bundle branches, and Purkinje network.

electrical conduction system of the ventricles the His-Purkinje system, which includes the bundle of His, the right and left bundle branches, and the Purkinje network.

electrical impulse the tiny electric-current that normally originates in the SA node automatically and is conducted through the electrical conduction system to the atria and ventricles, causing them to depolarize and contract.

electrical nonuniformity a condition of the ventricles during the vulnerable period of ventricular repolarization (i.e., the relative refractory period of the ventricles coincident with the peak of the T wave) when the ventricular muscle fibers may be completely repolarized, partially repolarized, or completely refractory. Stimulation of the ventricles at this point by an intrinsic electrical impulse, such as that generated by a PVC or by an extrinsic impulse from a cardiac pacemaker or an electrical countershock, may result in nonuniform conduction of the electrical impulse through the muscle fibers, setting up a reentry mechanism that may precipitate repetitive ventricular contractions and result in ventricular tachycardia or fibrillation. Responsible for the "R-on-T phenomenon."

electrical potential refers to the amount of electric current generated by the depolarization and repolarization of the heart and expressed as millivolts (mV). It ranges between 0 to ±20 mV or more.

electrocardiography (ECG) insensitive and nonspecific test for the evaluation of ventricular function.

12-lead electrocardiogram (ECG) the routine (or conventional) ECG consisting of three standard (bipolar) limb leads (leads I, II, and III), three augmented (unipolar) leads (leads aVR, aVL, and aVF), and six precordial (unipolar) leads (leads V1 V2, V3, V4, V5, and V6)

electrocardiogram, electrocardiography, electrocardiographic a record of the electrical activity of the heart

electrode a sensing device that detects electrical activity, such as that of the heart. May be positive or negative.

electrolysis the process of applying an electrical current across an anode and cathode in a solution, usually to create or enhance a chemical reaction

electrolyte a substance that when in solution dissociates into cations and anions, thus becoming capable of conducting electricity.

electrolyte imbalance abnormal concentrations of serum electrolytes within the body caused by excessive intake or loss of such electrolytes as calcium, carbonate, chloride, potassium, and sodium.

electromechanical dissociation (EMD) a condition of the heart in which the electrical activity of the heart is present and can be recorded on the ECG, but effective ventricular contractions, blood pressure, and pulse are absent.

electromechanical valve a mechanical valve system that responds to an electrical signal; also called an electrically powered mechanical valve.

electromyogram, electromyography, electromyographic an electrodiagnostic assessment of the activity of skeletal muscles

electron particle with a negative charge (-1) located outside the nucleus of an atom.

electron transport system movement of high-energy electrons (removed during glycolysis) down a chain of carrier molecules imbedded in the inner membrane of the mitochondria, resulting in the production of some 90% of the ATP formed during carbohydrate catabolism.

electronic capacitance transducer an electronic component that changes one form of energy to another based on the strength of the electrical charge stored in the unit.

electronically controlled PEEP valve a PEEP valve whose pressure limits are maintained by electrically operated valves.

electronic signature unique code or password that verifies the individual creating the entry and creates an individual "signature" on the record, then stores it on magnetic, optical, or some other computer storage media.

electrophysiology the recording and study of the electrical properties of living tissue

ELISA abbreviation for enzyme-linked immunosorbent assay, a test commonly used to detect the presence of antibodies to specific infectious agents, such as the HIV Virus

elongation the condition or process of being extended.

embolectomy a surgical incision into an artery for the removal of an embolus or clot, performed as emergency treatment for arterial embolization

embolism obstruction of a blood vessel by an embolus that reduces or stops blood flow, resulting in ischemia or necrosis of the tissue supplied by the blood vessel.

embolization the process by which an embolus forms and lodges in a branch of the vasculature

embolus a mass of solid, liquid, or gaseous material carried from one part of the circulatory system to another.

embryonic pertaining to the early stages (i.e., first three months) of fetal development.

emotional filter nonverbal, internal interpretation of another's actions or communication as seen in light of a judgment, emotional reaction or opinion of the listener.

empathy characteristic essential to nurturing a relationship: envisioning oneself in the place of another and then verbally conveying that you understand what it must feel like to be in that person's situation.

emphysema type of COPD occurring in patients who experience damage to the lung parenchyma; results in histopathologic evidence of alveolar wall destruction without fibrosis and physiologic evidence of decreased lung elastic recoil, resulting in bullae that eventually enlarge and compress adjacent lung tissue, impairing respiratory function.

empirical ascertained or discovered by observation emulsification the process of mixing two or more substances that are not mutually soluble into a uniform dispersion; specifically applies to the breakdown of fat globules in the intestines via the action of bile acids

empyema pus within the pleural space. A pleural fluid Gram stain that shows bacteria also qualifies

encephalitis inflammation of the brain

endarterectomy the surgical excision of the innermost lining of an artery to remove blockage

end-diastolic PVC a PVC occurring at about the same time that a QRS complex of the underlying rhythm is expected to occur.

end diastolic volume the volume of blood remaining in the left ventricle after the ventricle has contracted

endemic refers to a disease that is prevalent in a particular geographic area or in a population  

endobronchial within a bronchus

endobronchial biopsy method for sampling endoscopically visible exophytic central tumors or mucosal ulceration, irregularity, or infiltration.

endocarditis inflammation of endocardium and the heart valves, as caused by a variety of diseases

endocardium the lining of the heart chambers, containing small blood vessels and a few bundles of smooth muscle. It is continuous with the endothelium of the great blood vessels.

endocrine system the network of ductless glands and other structure that elaborate and secrete hormones directly into the bloodstream, affecting the function of specific target organs

endogenous growing within or arising from the body endorphin anyone of the neuropeptides composed of many amino acids, elaborated by the pituitary gland and acting on the central and peripheral nervous systems to reduce pain

endometriosis a growth of endometrial tissue at various sites outside the uterus

endometrium the lining of the uterus that changes with the menstrual cycle; if the ovum is fertilized, the endometrium serves as the place where implantation occurs

endoscopy examination of any cavity of the body with an endoscope

endothelium the layer of epithelial cells, originating from the mesoderm, that lines the cavities of the heart, the blood and lymph vessels, and the serous cavities of the body.

endotracheal referring to the lumen of the trachea; as in a tube that is inserted into the trachea

endotracheal intubation establishment of an artificial airway by placing a tube through the mouth or nose, through the glottis, and into the trachea.

endotracheal tube large-bore cathether inserted through the mouth or nose and into the trachea.

End Expiration-Evidence based Medicine

end-expiration the portion of a ventilatory cycle at which expiration stops (pre-inspiration).

end-inspiration the portion of a ventilatory cycle at which inspiration stops (pre-expiration).

end-tidal Pco2 Pco2 at end-exhalation (PETCO2).

end-tidal sampling the sampling of exhaled air late in a subject's expiration. This represents an attempt to perform analysis on gas assumed to be directly from the alveoli as opposed to deadspace gas.

enhanced automaticity an abnormal condition of latent pacemaker cells in which their firing rate is increased beyond their inherent rate because of a spontaneous increase in the slope of phase-4 depolarization. See Slope of phase-4 depolarization.

enoxaparin a low-molecular-weight (LMW) heparin used as an anticoagulant. See Anticoagulant.

enteral oral route (PO) of drug administration, passing into the gastrointestinal system.

enteral nutrition provision of nutrients through the GI tract when the patient is unable to chew or swallow.

enteral tube feeding (ETF) nutrition administration via direct access to the gastrointestinal tract, bypassing the mouth and throat in a patient who cannot eat but who has adequate gastric motility and emptying.

enteric of or pertaining to the intestinal tract  

enteric bacteria intestinal bacteria. 

Enterobacteriaceae a family of aerobic and anaerobic bacteria that includes both normal and pathogenic enteric microorganisms

entitlement a right or claim; alternatively the process of granting or providing a right, such as the right to adequate healthcare

entrainment device a device designed to add ambient gas into a primary gas stream. These are usually jet/Venturi devices.

entrainment nebulizer a nebulizer designed to entrain gas or liquids into the primary gas stream (see above).

entrainment reservoir the part of an entrainment nebulizer that contains the substance to be entrained and nebulized.

entry and exclusion criteria stipulations made before a study begins to determine how a subject or patient is to be entered into, excluded from, and withdrawn from a study.

enzyme an organic catalyst produced by living cells

enzyme-linked immunosorbent assay (ELISA) a test used to detect antibodies to the acquired immunodeficiency syndrome (AIDS) virus in blood serum

EOA abbreviation for esophageal obturator airway; the EOA consists of a cuffed hollow tube tipped with a soft plastic obturator at its tip; the tube passes through a mask and has several holes in its upper portion; once passed into the esophagus, the cuff is inflated, thereby preventing aspiration and allowing ventilation with positive pressure

eosinophil a cell or cellular structure that stains readily with the acid stain eosin; specifically, a granular leukocyte.

eosinophilia an increase in the number of eosinophils in the blood, accompanying many inflammatory conditions

eosinophilic granuloma rare, predominantly pulmonary disorder that occurs almost exclusively in smokers or ex­smokers between 10 and 40 years old; likely an inflammatory response by Langerhans cells to a component of tobacco smoke.

EPAP abbreviation for expiratory positive airway pressure, or the application of positive pressure to the airway during expiration only (as opposed to continuous positive airway pressure)

epicardial surface the outside surface of the heart.

epicardium one of the three layers of tissue that form the heart wall. It is composed of a single sheet of squamous epithelial cells overlying delicate connective tissue. Epicardium is the visceral portion (visceral layer) of the serous pericardium and folds back on itself to form the parietal portion of the serous pericardium.

epidemiologic studies studies for evaluating the relationships of various factors that determine the frequency and distribution of diseases within a human community.

epigastric refers to the upper middle region of the abdomen

epigastrium the part of the abdomen in the upper zone between the right and left hypochondriac regions epiglottis a flat cartilage that extends from the base of the tongue backward and upward

epiglottis cartilaginous structure overhanging the entrance to the larynx to prevent food from entering the larynx and trachea while swallowing.

epiglottitis an acute and often life-threatening infection of the upper airway, which causes severe obstruction secondary to supraglottic swelling; caused primarily by Haemophilus influenzae, type B, and affecting mainly children under the age of 5

epinephrine (Adrenalin) a hormone and drug produced by the adrenal gland and other tissues of the body. It is an alpha and beta stimulator causing an increase in blood pressure by means of peripheral artery vasoconstriction and an increase in cardiac output by increasing heart rate and force of ventricular contraction. Used in the treatment of bronchial asthma, acute allergic disorders, bradycardia from whatever cause, ventricular fibrillation/pulseless ventricular tachycardia, ventricular asystole, and pulseless electrical activity.

epiphysis (epiphyses), epiphyseal the long end of a bone where bone growth occurs

epistaxis bleeding from the nose, also called nosebleed.

epithelium the covering of the internal and external organs of the body, including the lining of vessels

Epstein-Barr virus the herpesvirus associated with infectious mononucleosis

eptifibatide a platelet GP IIb/IIIa receptor inhibitor that blocks the GP IIb/IIIa receptors on activated platelets from binding to vWF and fibrinogen, thus inhibiting platelet adhesion and aggregation and further thrombus formation.

equal pressure point (EPP) during forced exhalation, the point along an airway where the pressure inside its wall equals the intrapleural pressure; upstream beyond this point, the pleural pressure exceeds the pressure inside the airway, tending to promote bronchiolar collapse

equilibrium condition in which one or more forces are evenly balanced by opposite forces.

equiphasic deflection a biphasic deflection in which the sum of the positive (upright) deflection or deflections in an ECG are equal to that of the negative (inverted) deflection or deflections.

ergometer bicycle-like apparatus used for measuring the respiratory, muscular, and metabolic effects of exercise.

erythema a redness of the skin due to capillary congestion; caused by injury, inflammation, or infection

erythema nodosum a hypersensitivity vasculitis characterized by tender red subcutaneous nodules on the shins and associated with strep infections, TB, and sarcoidosis

erythrocyte red blood cell (RBC).

erythrocyte sedimentation rate (ESR) a measurable reflection of the acute-phase reaction in inflammation and infection

erythrocythemia an increase in the number of erythrocytes circulating in the blood

erythrocytosis the process resulting in an abnormal increase in the number of circulating red cells

erythropoiesis the process of erythrocyte production involving the maturation of a nucleated precursor into a hemoglobin-filled nucleus-free erythrocyte that is regulated by erythropoietin, a hormone produced by the kidney.

escape beat or complex a QRS complex arising in an escape (or secondary pacemaker) in the AV junction or ventricles when the underlying rhythm slows to less than the escape or secondary pacemaker's inherent firing rate. Such rhythms are called junctional or ventricular escape beats or complexes.

escape (or secondary) pacemaker a latent pacemaker in the AV junction or ventricles that takes over pacing the heart when the pacemaker of the underlying rhythm slows to less than the latent pacemaker's inherent firing rate or stops functioning altogether.

escape rhythm three or more consecutive QRS complexes that result when the underlying rhythm slows to less than the escape or secondary pacemaker's inherent firing rate, or stops altogether and the escape pacemaker takes over. Examples of escape rhythms are junctional escape rhythm and ventricular escape rhythm.

eschar scab or dry crust that develops after trauma, such as a thermal or chemical burn, infection, or excoriating skin disease.

escharotomy surgical incision into necrotic tissue resulting from a severe burn to prevent edema from generating sufficient interstitial pressure to impair capillary filling, causing ischemia.

esmolol a beta-adrenergic blocking agent used primarily in the treatment of tachyarrhythmias, hypertension, angina pectoris, and acute MI.

esophageal gastric tube airway (EGTA) a type of artificial airway that consists of a double lumen tube that passes through a tight-fitting face mask and extends through the mouth into the esophagus, this portion has an inflatable cuff above the distal opening. The oral portion of the airway has a ventilation tube with holes through which gas from a resuscitation device ventilates the lungs.

esophageal obturator airway (EOA) a type of artificial airway used in emergency situations; it consists of a blind tube that passes through a tight-fitting face mask and extends through the mouth into the esophagus, this portion has an inflatable cuff. The oral portion of the airway has holes through which gas from a resuscitation device is forced into the lungs.

esophageal opening pressure the oral pressure at which the esophagus distends and opens, allowing gas to insufflate the stomach; estimated to range from 20 to 25 cm H20 ethylene oxide a gas used to sterilize surgical instruments and other supplies

esophagoscopy examination of the esophagus with an esophagoscope

etiology study of the cause of disease.

EtO common abbreviation for ethylene oxide

eupnea normal, spontaneous breathing.

Eustachian tubes bilateral tubes that connect the nasopharynx to the middle ear and mastoid sinus evacuate to remove or withdraw from, especially to empty of air and create a vacuum

evaporation the process by which liquids change into the vapor state. This occurs because of changes in temperature, pressure, and vapor pressure gradients.

evidence-based medicine (EBM) comprehensive approach to systematically document achievable health care outcomes across the disciplines; also called evidence-based health care (EBH).

Ex Vivo-Exudative Pleural Effusion

ex vivo outside the body exacerbate to worsen

exacerbation an increase in the severity of a disease or aggravation of its symptoms

excitability the ability of a cell to reach its threshold potential and respond to a stimulus or irritation. The lower the stimulus needed to activate a cell, the more excitable the cell; conversely, the greater the stimulus needed, the less excitable the cell.

exclusive provider organization managed care model in which choice is completely eliminated and enrollees must employ the physician and hospital stipulated in the plan; the most affordable but most restrictive of the managed care models.

excretion elimination of waste products.

excursion the extent of movement from a central position or axis.

exercise assessment this assessment performs two functions: (1) It quantitates the level of disability and provides information for setting initial exercise loads and program expectations. (2) It provides insight into the various cardiorespiratory factors that are involved in the functional disabilities.

exercise testing testing method that measures physiologic reserve and functional capacity that cannot be determined from resting measurements; exercise testing delineates the reserve of each of the contributing subcomponents of respiration, and allows assessment of functional status through determination of maximal power output and oxygen consumption.

exercise-induced asthma form of asthma characterized by transient airway obstruction, typically occurring 5 to 15 minutes after strenuous exertion; prevalent in 90% of individuals with asthma.

exhalation timer a control that determines the length of the expiratory portion of the respiratory cycle.  

exhalation valve a one-way valve system through which exhaled gases exit the ventilator and its circuit.

exhalation valve leak alarm a device that warns that the integrity of the exhalation valve has failed.

exhaled nitric oxide marker of airway inflammation, particularly useful in both acute and chronic asthma in both children and adults.

exhausted fuel cell alarm a warning that the sensing mechanism in a fuel cell gas analyzer is not functional.

exotoxin bacterial toxins excreted outside of the bacterial cell

expectorant a chemical agent that promotes the expectoration of respiratory tract secretions, usually by increasing their production or by lowering their viscosity

expectoration clearing the lungs by coughing up and spitting out matter.

expiratory flow gradient control a device that allows for adjustment of expiration by manipulation of back pressure and expiratory pressure gradients.

expiratory flow time interval from the start of expiratory flow to the end of expiratory flow.

expiratory pause time interval from the end of expiratory flow to the start of inspiratory flow; often initiated to measure auto-PEEP.

expiratory phase respiration period during which all mechanics from the start of expiratory flow to the end of expiratory flow occur, including those associated with expiratory hold or pause, until the start of inspiratory flow.

expiratory positive airway pressure (EPAP) pressure applied to the airway during the expiratory phase with ventilators designed for noninvasive ventilation; synonymous with CPAP or PEEP.

expiratory reserve volume (ERV) the total amount of gas that can be exhaled from the lung following a quiet exhalation

expiratory resistance control an adjustable spring that allows back pressure to increase forces opposing expiratory flow.

expiratory retard a device designed to increase expiratory time by increasing the resistance to expiratory flow.

expiratory servo valve the device that controls the expiratory scissors valve in the Siemens 900 series mechanical ventilator.

expiratory time time interval from the start of expiratory flow to the start of inspiratory flow; components include expiratory flow time and expiratory pause time.

exponent useful means of abbreviating large or small (negative) numbers for convenience and ease of comparison, using superscripted numerals to indicate, for example, powers of 10, as seen in scientific notation; these superscripts, or exponents of 10, indicate where to move the decimal point to obtain the complete number.

exsanguination excessive loss of blood from a part

extensive anterior MI a myocardial infarction commonly caused by occlusion of the left anterior descending (LAD) coronary artery alone or in conjunction with the anterolateral marginal artery of the left circumflex coronary artery.

external cardiac pacing Transcutaneous pacing (TCP, TC pacing) a technique to treat bradycardias from whatever cause, ventricular asystole, and pulseless electrical activity using an external artificial pacemaker.

external compressor large, water-cooled, piston-type compressor that provides compressed gas from wall outlets.

external IMV reservoir a reservoir bag or tubing that provides a volume of gas at a predetermined concentration in a volume large enough to accommodate the patient's IMV volume.

external IMV system a reservoir, tubing, gas source, and valve system attached to the outside of a ventilator.

external oblique abdominal muscle group that functions as an accessory muscle of ventilation

external respiration gas exchange between the pulmonary capillaries and the alveoli.

extra-alveolar air distinctive radiographic indicator, in thoracic imaging, of pneumothorax, pneumomediastinum, or interstitial emphysema.

extracellular occurring outside a cell or cell tissue or in cavities or spaces between cell layers or groups of cells

extracellular fluid (ECF) body fluid comprising interstitial fluid and blood plasma. 

extracorporeal something that is outside the body, as extracorporeal circulation, in which venous blood is diverted outside the body to a heart-lung machine and returned to the body through a femoral or other artery

extracorporeal carbon dioxide removal (ECC02R) the procedure whereby blood is passed from the patient through an external membrane, which filters carbon dioxide in order to support ventilation

extracorporeal membrane oxygenation (ECMO) the procedure whereby venous blood is pumped outside the body to a heart-lung machine for oxygenation and returned to the body

extra corporeal life support (ECLS) management technique for improving oxygenation and reducing ventilating pressures in selected full-term neonates through cannulation of the right heart; blood is drained from this cannula into a circuit containing a membrane oxygenator and a pump so that oxygen circulates through one side of the membrane and blood is pumped through the other side of the membrane, leading to oxygen diffusion into the blood and carbon dioxide elimination from the blood for its reinfusion into the infant.

extrasystole a premature beat or contraction independent of the underlying rhythm caused by an electrical impulse originating in an ectopic focus in the atria, AV junction, or ventricles. Examples of extrasystoles are premature atrial contractions (PAC's), premature junctional contractions (PJC's), and premature ventricular contractions (PVC's).

extrathoracic outside the thorax

extravascular outside a vessel.

extrinsic allergic alveolitis an inflammatory form of interstitial pneumonia that results from a Type III or immune complex antigen-antibody reactions to certain organic dusts

extrinsic asthma asthma associated with external allergens.

extubation process of removal of an endotracheal tube.

exudate fluid, cells, or cellular debris that has oozed into tissue because of injury or swelling

exudative relating to the oozing of fluid and other materials from cells and tissues, usually as a result of inflammation or injury

exudative pleural effusion any pleural effusion high in protein or LDH that implies inflammation or vascular injury on the pleural surface