Respiratory Abbreviations, Acronyms, and Symbols (List) (2024)

What does ABG stand for? How about SIMV? What is an HME?

If you haven’t noticed, hundreds of abbreviations, acronyms, symbols, and medical terms are used in respiratory care. And respiratory therapists (and students) need to know what they all mean.

That is why we put together this comprehensive list of the most important abbreviations and acronyms that you (as a respiratory therapist) must be familiar with.

25+ RRT Cheat Sheets and Quizzes

# | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

#

• Δ – change in
• μ – micro-
• μg – microgram
• μm – micrometer

A

• A – alveolar
• a – arterial
• AARC – American Association for Respiratory Care
• ABC – airway, breathing, circulation
• ABG – arterial blood gas
• A/C – assist/control
• ACBT – active cycle of breathing technique
• ACLS – advanced cardiovascular life support
• ADH – antidiuretic hormone
• AIDS – acquired immunodeficiency syndrome
• AII – airborne infection isolation
• ALI – acute lung injury
• ALV – adaptive lung ventilation
• AOP – apnea of prematurity
• APRV – airway pressure release ventilation
• ARDS – acute respiratory distress syndrome
• ARF – acute respiratory failure
• ASV – adaptive support ventilation
• ATC – automatic tube compensation
• ATM – atmospheric pressure
• ATPD – ambient temperature and pressure, dry
• ATPS – ambient temperature and pressure, saturated with water vapor
• auto-PEEP – unintended positive end-expiratory pressure
• AV – arteriovenous

B

• B – barometric
• BAC – blood alcohol content
• BE – base excess
• BiPAP – bilevel positive airway pressure
• BLS – basic life support
• BP – blood pressure
• BPD – bronchopulmonary dysplasia
• BSA – body surface area
• BTPS – body temperature and pressure, saturated with water vapor
• BUN – blood urea nitrogen

C

• c – capillary
• °C – degrees Celsius
• CaO2 – arterial content of oxygen
• C(a-v)O2 – arterial-to-mixed venous oxygen content difference
• CAD – coronary artery disease
• cc – cubic centimeter
• CcO2 – content of oxygen of the ideal alveolar capillary
• Cd – dynamic compliance
• CDC – Centers for Disease Control and Prevention
• CDH – congenital diaphragmatic hernia
• CEU – continuing education unit
• CF – cystic fibrosis
• CHF – congestive heart failure
• CI – cardiac index
• CL – lung compliance
• cm – centimeters
• cmH2O – centimeters of water pressure
• CMV – continuous mandatory ventilation
• CNS – central nervous system
• CO – carbon monoxide
• CO2 – carbon dioxide
• COHb – carboxyhemoglobin
• COPD – chronic obstructive pulmonary disease
• CPAP – continuous positive airway pressure
• CPP – cerebral perfusion pressure
• CPR – cardiopulmonary resuscitation
• CPT – chest physical therapy
• CRCE – continuing respiratory care education
• Cs static – compliance
• CSF – cerebrospinal fluid
• CT – computed tomography
• CvO2 – venous oxygen content
• CVP – central venous pressure

D

• D – diffusing capacity
• d – diameter
• DC – discontinue
• DKA – diabetic ketoacidosis
• DLCO – Diffusing Capacity of the Lungs for Carbon Monoxide
• DNA – deoxyribonucleic acid
• DNI – do not intubate
• DNR – do not resuscitate
• DOA – dead on arrival
• DOB – date of birth
• DO2 – oxygen delivery
• DPI – dry powder inhaler
• Dr. – doctor
• DVT – deep venous thrombosis
• Dx – diagnosis

E

• E – elastance
• ECG – electrocardiogram
• ECLS – extracorporeal life support
• ECMO – extracorporeal membrane oxygenation
• EHR – electronic health record
• EKG – electrocardiogram
• EMR – electronic medical record
• EPAP – end positive airway pressure
• ERV – expiratory reserve volume
• ET – endotracheal tube
• EtCO2 – end-tidal CO2

F

• °F – degrees Fahrenheit
• f – frequency (respiratory rate)
• FDA – Food and Drug Administration
• FEF – forced expiratory flow
• FEFmax – maximal forced expiratory flow achieved during FVC
• FEV1 – forced expiratory volume at 1 second
• FIF – forced inspiratory flow
• FiO2 – fraction of inspired oxygen
• FIVC – forced inspiratory vital capacity
• FRC – functional residual capacity
• FVC – forced vital capacity
• f/VT – rapid shallow breathing index

G

• Gaw – airway conductance
• GCS – Glasgow coma scale
• g/dl – grams per deciliter
• GERD – gastroesophageal reflux disease
• GI – gastrointestinal
• GSW – gunshot wound

H

• [H+] – hydrogen ion concentration
• HAI – hospital-acquired infection
• HAP – hospital-acquired pneumonia
• Hb – hemoglobin
• HBO – hyperbaric oxygen therapy
• HCO3- – bicarbonate
• H2CO3 – carbonic acid
• He – helium
• He/O2 – heliox
• HFJV – high-frequency jet ventilation
• HFNC – high-flow nasal cannula
• HFOV – high-frequency oscillatory ventilation
• HFPPV – high-frequency positive pressure ventilation
• HFV – high-frequency ventilation
• HMD – hyaline membrane disease
• HME – heat and moisture exchanger
• H2O – water
• HR – heart rate
• ht – height
• Hz – hertz

I

• IBW – ideal body weight
• IC – inspiratory capacity
• ICP – intracranial pressure
• ICU – intensive care unit
• ID – inner diameter
• I:E – inspiratory-to-expiratory ratio
• ILD – interstitial lung disease
• IMV – intermittent mandatory ventilation
• iNO – inhaled nitric oxide
• IPAP – inspiratory positive airway pressure
• IPPB – intermittent positive pressure breathing
• IPPV – intermittent positive pressure ventilation
• IRDS – infant respiratory distress syndrome
• IRV – inverse ratio ventilation
• IRV – inspiratory reserve volume
• IV – intravenous
• IVC – inspiratory vital capacity
• IVH – intraventricular hemorrhage

J

• J – joule
• JVD – jugular venous distention

K

• K – potassium
• KCl – potassium chloride
• kcal – kilocalorie
• kg – kilogram

L

• L – liter
• LAP – left atrial pressure
• lb – pound
• LBW – low birth weight
• LLL – left lower lobe
• LTACH – long-term acute care hospital
• LUL – left upper lobe

M

• MABP – mean arterial blood pressure
• MAP – mean arterial pressure
• MAS – meconium aspiration syndrome
• MDI – metered dose inhaler
• MDR – multidrug resistant
• mEq/L – milliequivalents per liter
• MEP – maximum expiratory pressure
• metHb – methemoglobin
• mg – milligram
• mg/dl – milligrams per deciliter
• MI – myocardial infarction
• MI-E – mechanical insufflation-exsufflation
• MIF – maximum inspiratory force
• MIP – maximum inspiratory pressure
• mL – milliliter
• mm – millimeter
• MMAD – median mass aerodynamic diameter
• mmHg – millimeters of mercury
• mmol – millimole
• MMV – mandatory minute ventilation
• MOV – minimal occluding volume
• MRI – magnetic resonance imaging
• msec – millisecond
• MV – mechanical ventilation
• MVV – maximum voluntary ventilation

N

• NaCl – sodium chloride
• NAVA – neurally adjusted ventilatory assist
• NBRC – National Board of Respiratory Care
• NICU – neonatal intensive care unit
• NIF – negative inspiratory force
• NIH – National Institutes of Health
• NIV – noninvasive ventilation
• NMBA – neuromuscular blocking agent
• NO – nitric oxide
• NO2 – nitrous oxide
• NP – nasopharyngeal
• NPO – nothing by mouth
• NPV – negative pressure ventilation
• NPPV – noninvasive positive pressure ventilation
• NSAIDs – nonsteroidal antiinflammatory drugs
• NRDS – neonatal respiratory distress syndrome

O

• O2 – oxygen
• O2Hb – oxygenated hemoglobin
• OHDC – oxyhemoglobin dissociation curve
• OR – operating room
• OSA – obstructive sleep apnea
• OTC – over the counter

P

• P – pressure
• ΔP – change in pressure
• P50 – PO2 at which hemoglobin is 50% saturated
• PA – pulmonary artery
• P(A-a)O2 – alveolar-to-arterial partial pressure of oxygen
• PaCO2 – partial pressure of carbon dioxide in arterial blood
• Pal – alveolar pressure
• PAO2 – partial pressure of oxygen in the alveoli
• PaO2 – partial pressure of oxygen in the arteries
• PaO2/FiO2 – ratio of arterial PO2 to FiO2
• PaO2/PAO2 – ratio of arterial PO2 to alveolar PO2
• PAOP – pulmonary artery occlusion pressure
• PAP – pulmonary artery pressure
• PAV – proportional assist ventilation
• Paw – mean airway pressure
• PB – barometric pressure
• PC-CMV – pressure-controlled continuous mandatory ventilation
• PCO2 – partial pressure of carbon dioxide
• PC-SIMV – pressure-controlled synchronized intermittent mandatory ventilation
• PCV – pressure-controlled ventilation
• PCWP – pulmonary capillary wedge pressure
• PDA – patent ductus arteriosus
• PE – pulmonary embolism
• PEmax – maximal expiratory pressure
• PEA – pulseless electrical activity
• PEEP – positive end-expiratory pressure
• PEFR – peak expiratory flow rate
• PetCO2 – partial pressure of end-tidal carbon dioxide
• PFT – pulmonary function testing
• pH – potential of hydrogen
• PIP – peak inspiratory pressure
• PISS – pin-indexed safety system
• PL – transpulmonary pressure
• pMDI – pressurized metered dose inhaler
• PO2 – partial pressure of oxygen
• Ppeak – peak inspiratory pressure
• PPHN – primary pulmonary hypertension of the neonate
• Ppl – intrapleural pressure
• Pplat – plateau pressure
• ppm – parts per million
• PPV – positive pressure ventilation
• PRVC – pressure regulated volume control
• PS – pressure support
• psi – pounds per square inch
• psig – pounds per square inch gauge
• PSmax – maximum pressure support
• PSV – pressure support ventilation
• PTA – transairway pressure
• Ptm – transmural pressure
• PTR – transrespiratory pressure
• PTSD – posttraumatic stress disorder
• P-V – pressure-volume
• PVC – premature ventricular contraction
• PvO2 – partial pressure of oxygen in mixed venous blood
• PVR – pulmonary vascular resistance
• Pw – transthoracic pressure

Q

• Q – perfusion
• q – every
• qh – every hour
• q2h – every 2 hours
• q4h – every 4 hours
• q6h – every 6 hours
• q8h – every 8 hours
• qhs – every night at bed time
• qid – four times a day
• qam – every morning
• qod – every other day

R

• RAP – right atrial pressure
• Raw – airway resistance
• RCP – respiratory care practitioner
• RDS – respiratory distress syndrome
• REE – resting energy expenditure
• RLL – right lower lobe
• ROP – retinopathy of prematurity
• RQ – respiratory quotient
• RRT – registered respiratory therapist
• RSV – respiratory syncytial virus
• RT – respiratory therapist
• RTZ – respiratory therapy zone
• RUL – right upper lobe
• RV – residual volume
• RV/TLC% – ratio of residual volume to total lung capacity
• RVP – right ventricular pressure

S

• SA – sinoatrial
• SaO2 – arterial oxygen saturation
• SEERS – severe epidemic enterovirus respiratory syndrome
• SI – stroke index
• SIDS – sudden infant death syndrome
• SIMV – synchronized intermittent mandatory ventilation
• Sine – sinusoidal
• SNF – skilled nursing facility
• SpO2 – oxygen saturation
• STPD – standard temperature, pressure saturated
• SV – stroke volume
• SVC – slow vital capacity
• SvO2 – mixed venous oxygen saturation
• SVN – small volume nebulizer
• SVR – systemic vascular resistance

T

• t – time
• T – temperature
• TB – tuberculosis
• TBI – traumatic brain injury
• Tc – time constant
• tcCO2 – transcutaneous CO2
• TCT – total cycle time
• TE – expiratory time
• TI – inspiratory time
• tid – three times per day
• TJC – The Joint Commission
• TLC – total lung capacity
• TOF – tetralogy of Fallot
• torr – measurement of pressure that is equivalent to mmHg
• TTN – transient tachypnea of the neonate
• TTOT – transtracheal oxygen therapy
• TV – tidal volume

U

• UA – urinalysis
• UOP – urine output
• URI – upper respiratory infection
• USN – ultrasonic nebulizer
• UTI – urinary tract infection
• UV – ultraviolet

V

• VE – expired minute ventilation
• VA – alveolar gas volume
• VALI – ventilator-associated lung injury
• VAP – ventilator-associated pneumonia
• VAPS – volume-assured pressure support
• VC – vital capacity
• VC-CMV – volume-controlled continuous mandatory ventilation
• VC-IMV – volume-controlled intermittent mandatory ventilation
• VD – physiologic dead space
• Vfib – ventricular fibrillation
• VILI – ventilator-induced lung injury
• VLBW – very low birth weight
• VO2 – oxygen consumption per minute
• VS – volume support
• Vtach – ventricular tachycardia
• VT – tidal volume
• VTA – alveolar tidal volume
• vol% – volume per 100 ml of blood
• V/Q – ventilation/perfusion ratio
• VSV – volume support ventilation

W

• W – work
• WBC – white blood cell
• WOB – work of breathing
• wt. – weight
• wye – Y connector

X

• x – any variable
• x – multiplied by
• x-ray – radiograph
• XRT – radiotherapy

Y

• Y – wye connector
• yo – years old
• yrs – years

Z

• Z – atomic number
• Zn – zinc

• Egan’s Fundamentals of Respiratory Care. 12th ed., Mosby, 2020.
• Clinical Application of Mechanical Ventilation. 4th ed., Cengage Learning, 2013.
• Pilbeam’s Mechanical Ventilation: Physiological and Clinical Applications. 6th ed., Mosby, 2015.
• Mosby’s Respiratory Care Equipment. 10th ed., Mosby, 2017.
• Rau’s Respiratory Care Pharmacology. 10th ed., Mosby, 2019.
• Wilkins’ Clinical Assessment in Respiratory Care. 8th ed., Mosby, 2017.
• Cardiopulmonary Anatomy & Physiology: Essentials of Respiratory Care. 7th ed., Cengage Learning, 2019.
• Clinical Manifestations and Assessment of Respiratory Disease. 8th ed., Mosby, 2019.
• Ruppel’s Manual of Pulmonary Function Testing. 11th ed., Mosby, 2017.
• Neonatal and Pediatric Respiratory Care. 5th ed., Saunders, 2018.

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