[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"menu":3,"$fqUAXloG_lJovAceTKakTpsl2QCsmQyrxEEtY8r1Cg7U":210},{"main":4,"mainTranslated":17,"footer":45,"footerTranslated":109},[5,8,11,14],{"title":6,"url":7},"Course library","https:\u002F\u002Fwww.medmastery.com\u002Fcourse-library",{"title":9,"url":10},"Pricing","https:\u002F\u002Fwww.medmastery.com\u002Fpricing",{"title":12,"url":13},"Earn credits","https:\u002F\u002Fwww.medmastery.com\u002Fcme-credits",{"title":15,"url":16},"Institutions","https:\u002F\u002Fwww.medmastery.com\u002Finstitutions",{"de":18,"es":27,"fr":36},[19,21,23,25],{"title":20,"url":7},"Kurse",{"title":22,"url":10},"Preise",{"title":24,"url":13},"CME-Punkte",{"title":26,"url":16},"Organisationen",[28,30,32,34],{"title":29,"url":7},"Biblioteca de cursos",{"title":31,"url":10},"Precios",{"title":33,"url":13},"Gana créditos",{"title":35,"url":16},"Instituciones",[37,39,41,43],{"title":38,"url":7},"Cours",{"title":40,"url":10},"Tarifs",{"title":42,"url":13},"Obtenir des crédits",{"title":44,"url":16},"Établissements",[46,59,79,97],{"title":47,"group":48,"menu":49},"Company",true,[50,53,56],{"title":51,"url":52},"Our teachers","https:\u002F\u002Fwww.medmastery.com\u002Fteachers",{"title":54,"url":55},"About us","https:\u002F\u002Fwww.medmastery.com\u002Fabout-us",{"title":57,"url":58},"Work with us","https:\u002F\u002Fwww.medmastery.com\u002Fwork-with-us",{"title":60,"group":48,"menu":61},"Product",[62,64,67,70,73,76,78],{"title":63,"url":7},"Courses",{"title":65,"url":66},"Magazine","https:\u002F\u002Fwww.medmastery.com\u002Fmagazine",{"title":68,"url":69},"Podcast","https:\u002F\u002Fwww.medmastery.com\u002Fpodcasts",{"title":71,"url":72},"Webinars","https:\u002F\u002Fwww.medmastery.com\u002Fwebinars",{"title":74,"url":75},"Guides","https:\u002F\u002Fwww.medmastery.com\u002Fguides",{"title":15,"url":77},"https:\u002F\u002Fwww.medmastery.com\u002Finstitutions\u002F",{"title":9,"url":10},{"title":80,"group":48,"menu":81},"Legal",[82,85,88,91,94],{"title":83,"url":84},"Imprint","https:\u002F\u002Fwww.medmastery.com\u002Fimprint",{"title":86,"url":87},"Newsletter policy","https:\u002F\u002Fwww.medmastery.com\u002Fnewsletter-privacy-policy",{"title":89,"url":90},"Privacy policy","https:\u002F\u002Fwww.medmastery.com\u002Fprivacy-policy",{"title":92,"url":93},"Cookie Policy","https:\u002F\u002Fwww.medmastery.com\u002Fcookie-policy",{"title":95,"url":96},"Terms","https:\u002F\u002Fwww.medmastery.com\u002Fterms",{"title":98,"group":48,"menu":99},"Customer support",[100,103,106],{"title":101,"url":102},"FAQs","https:\u002F\u002Fwww.medmastery.com\u002Ffaqs",{"title":104,"url":105},"Contact","https:\u002F\u002Fwww.medmastery.com\u002Fcontact",{"title":107,"url":108},"support@medmastery.com","mailto:support@medmastery.com",{"de":110,"es":143,"fr":177},[111,118,128,137],{"title":112,"group":48,"menu":113},"Unternehmen",[114,116,117],{"title":115,"url":52},"Unsere Dozentinnen und Dozenten",{"title":54,"url":55},{"title":57,"url":58},{"title":119,"group":48,"menu":120},"Produkt",[121,122,123,124,125,126,127],{"title":20,"url":7},{"title":65,"url":66},{"title":68,"url":69},{"title":71,"url":72},{"title":74,"url":75},{"title":26,"url":77},{"title":22,"url":10},{"title":129,"group":48,"menu":130},"Rechtliches",[131,133,134,135,136],{"title":132,"url":84},"Impressum",{"title":86,"url":87},{"title":89,"url":90},{"title":92,"url":93},{"title":95,"url":96},{"title":138,"group":48,"menu":139},"Kundenservice",[140,141,142],{"title":101,"url":102},{"title":104,"url":105},{"title":107,"url":108},[144,151,162,171],{"title":145,"group":48,"menu":146},"Empresa",[147,149,150],{"title":148,"url":52},"Nuestros profesores",{"title":54,"url":55},{"title":57,"url":58},{"title":152,"group":48,"menu":153},"Producto",[154,156,157,158,159,160,161],{"title":155,"url":7},"Cursos",{"title":65,"url":66},{"title":68,"url":69},{"title":71,"url":72},{"title":74,"url":75},{"title":35,"url":77},{"title":31,"url":10},{"title":163,"group":48,"menu":164},"Información legal",[165,167,168,169,170],{"title":166,"url":84},"Aviso legal",{"title":86,"url":87},{"title":89,"url":90},{"title":92,"url":93},{"title":95,"url":96},{"title":172,"group":48,"menu":173},"Atención al cliente",[174,175,176],{"title":101,"url":102},{"title":104,"url":105},{"title":107,"url":108},[178,185,196,204],{"title":179,"group":48,"menu":180},"Entreprise",[181,183,184],{"title":182,"url":52},"Nos enseignants",{"title":54,"url":55},{"title":57,"url":58},{"title":186,"group":48,"menu":187},"Produit",[188,189,190,191,192,193,194],{"title":38,"url":7},{"title":65,"url":66},{"title":68,"url":69},{"title":71,"url":72},{"title":74,"url":75},{"title":15,"url":77},{"title":195,"url":10},"Tarification",{"title":197,"group":48,"menu":198},"Mentions légales",[199,200,201,202,203],{"title":197,"url":84},{"title":86,"url":87},{"title":89,"url":90},{"title":92,"url":93},{"title":95,"url":96},{"title":205,"group":48,"menu":206},"Service client",[207,208,209],{"title":101,"url":102},{"title":104,"url":105},{"title":107,"url":108},{"content":211,"related":282,"meta":353,"internal":363},{"title":212,"leadIn":213,"category":214,"elements":217,"becomeAnExpert":250,"author":272,"readDuration":280,"readDurationFormatted":281},"Measuring diffusing capacity","Understand diffusing capacity and how to measure it when assessing lung disease.",{"id":215,"name":216},1,"Course previews",[218,228,233,238,245],{"type":219,"data":220},"video",{"readDurationInSeconds":221,"video":222},355,{"platform":223,"name":212,"url":224,"size":225},"YouTube","https:\u002F\u002Fwww.youtube.com\u002Fwatch?v=MubR2lBiOis",{"width":226,"height":227},200,113,{"type":229,"data":230},"free_text",{"readDurationInSeconds":231,"text":232},10.666666666666666,"\u003Cp>Measuring diffusing capacity is a great way to determine whether the lungs are effectively transporting gas in and out of the blood. By the end of this video, from our Pulmonary Function Testing Essentials course, you'll understand how diffusing capacity is measured and used for assessing lung disease.\u003C\u002Fp>",{"type":229,"data":234},{"readDurationInSeconds":235,"title":236,"text":237},18.133333333333333,"Join our Pulmonary Function Testing Essentials course today!","\u003Cp>Take a deep dive into our \u003Cstrong>\u003Ca href=\"https:\u002F\u002Fwww.medmastery.com\u002Fcourse\u002Fpulmonary-function-testing-essentials\">Pulmonary Function Testing Essentials\u003C\u002Fa> \u003C\u002Fstrong>course and learn how to apply PFT interpretation guidelines to clinical cases. You'll learn when to use spirometry in your daily clinical practice, what tests to order, and how to interpret results. Complex concepts, like lung volumes, spirometry, diffusing capacity, bronchodilator responsiveness, and obstructive and restrictive patterns, will become second nature to you once you’ve completed this course.\u003C\u002Fp>",{"type":239,"data":240},"cta",{"readDurationInSeconds":241,"text":242,"buttonText":243,"buttonUrl":244},3.466666666666667,"Become a great clinician with our video courses and workshops","Start learning for free","https:\u002F\u002Fwww.medmastery.com\u002Fuser\u002Fregister",{"type":229,"data":246},{"readDurationInSeconds":247,"title":248,"text":249},136,"Video Transcript","\u003Cp dir=\"ltr\">\u003Cstrong>[00:00:00]\u003C\u002Fstrong> Diffusing capacity is a very useful test to assess for the presence of lung disease and its effect on gas exchange. The test measures the efficiency with which the test gas moves across the alveolar capillary membrane, reflecting changes and diffusion of intrinsic alveolar gases, most notably oxygen. Interestingly, carbon monoxide has emerged as the most \u003C\u002Fp>\u003Cp dir=\"ltr\">\u003Cstrong>[00:00:30] \u003C\u002Fstrong>practical test gas. This is because of its great affinity for hemoglobin, which means changes in the measured value reflect the status of the alveolar capillary membrane, rather than the reaction rate of carbon monoxide with hemoglobin, in red blood cells. Diffusing capacity of carbon monoxide or DLCO, although nonspecific, is highly sensitive in assessing lung function in a wide variety of pulmonary \u003C\u002Fp>\u003Cp dir=\"ltr\">\u003Cstrong>[00:01:00]\u003C\u002Fstrong> and non-pulmonary disease states affecting gas exchange. Let's examine the underlying physiology of diffusion across the lung. As demonstrated by Fick's law, a number of factors influence the movement or flux of gas molecules across the alveolar capillary membrane. These include the surface area of the membrane, the thickness of the membrane, the solubility of the gas, \u003C\u002Fp>\u003Cp dir=\"ltr\">\u003Cstrong>[00:01:30]\u003C\u002Fstrong> the molecular weight of the gas, and the driving pressure or pressure gradient across the alveolar capillary membrane. Even though not included in Fick's law, these factors also influence flux—the resistance to diffusion across the red blood cell membranes, the reaction rate of the gas with hemoglobin, and the capillary blood volume.\u003C\u002Fp>\u003Cp dir=\"ltr\">\u003Cstrong>[00:02:00]\u003C\u002Fstrong> Conceptually, diffusing capacity (DL) represents the amount of test gas transferred per unit of time (V) relative to the driving pressure for the gas across the alveolar capillary membrane (PA – PC). How does this relate to diffusion of carbon monoxide? The diffusing capacity of carbon monoxide (DLCO) is the amount of carbon monoxide transferred across the \u003C\u002Fp>\u003Cp dir=\"ltr\">\u003Cstrong>[00:02:30]\u003C\u002Fstrong> lung per minute, represented by VCO, divided by the driving pressure (PACO – PCCO). PACO is the partial pressure of carbon monoxide in the alveolus, and PCCO is the partial pressure of carbon monoxide in the pulmonary capillaries. Let's examine the individual terms. VCO is calculated as the difference in carbon monoxide content between [00:03:00] inspired and expired gas samples. That leaves determination of alveolar, pulmonary, and capillary carbon monoxide concentrations to enable the calculation. In non-smokers, PCCO is zero. If VCO is calculated as the difference between inspiratory and expiratory values, DLCO can be calculated once the alveolar concentration of carbon monoxide \u003C\u002Fp>\u003Cp dir=\"ltr\">\u003Cstrong>[00:03:30]\u003C\u002Fstrong> (PACO) is determined.There are two general methods of measuring diffusing capacity: the single-breath method and the steady-state method. We'll focus on the single-breath method. In the single-breath method, the patient takes a few tidal volume breaths followed by expiration to residual volume. The patient is then asked to take a full inspiration to TLC of a gas \u003C\u002Fp>\u003Cp dir=\"ltr\">\u003Cstrong>[00:04:00]\u003C\u002Fstrong> mixture, which contains 0.3% carbon monoxide. The patient holds his or her breath for ten seconds and then rapidly exhales. The concentration of carbon monoxide is measured using a carbon monoxide meter, then a rather complicated equation is used to calculate the diffusing capacity. It includes measurement of lung or alveolar volume based on plethysmography or helium delusion techniques \u003C\u002Fp>\u003Cp dir=\"ltr\">\u003Cstrong>[00:04:30] \u003C\u002Fstrong>and measurements of alveolar carbon monoxide concentration at the beginning of the breath hold and the final concentration of carbon monoxide at the end of the breath hold. A variety of conditions may affect diffusing capacity and these can be understood by considering Fick's law discussed earlier. For example, interstitial lung disease characterized by a thickened alveolar capillary membrane \u003C\u002Fp>\u003Cp dir=\"ltr\">\u003Cstrong>[00:05:00]\u003C\u002Fstrong> increases the diffusion pathway for oxygen and reduces the DLCL. Emphysema, characterized by loss of alveolar walls and loss of surface area for diffusion, also produces a reduction in DLCL. On the other hand, polycythemia and alveolar hemorrhage increase diffusing capacity, as the increase in hemoglobin within the lungs provides a sink for carbon monoxide. \u003C\u002Fp>",{"courses":251,"showAwardsBelow":48},[252],{"id":253,"isFreeCmeCourse":254,"title":255,"type":256,"specialization":257,"teachers":259,"cmeCredits":261,"teacherIllustration":262,"backgroundImage":263,"relativeUrl":264,"lastChanged":265,"created":266,"description":267,"relativeURL":264,"meta":268},5730,false,"Pulmonary Function Testing Essentials","course",[258],"Pulmonary",[260],"Michael A. Grippi, MD",4,"https:\u002F\u002Fmedmastery-backend-prod-kjbeds.s3.eu-west-1.amazonaws.com\u002Fmedia\u002Fimages\u002F99f55eef-50ef-4b84-a483-3d79e6f6691b","https:\u002F\u002Fmedmastery-backend-prod-kjbeds.s3.eu-west-1.amazonaws.com\u002Fmedia\u002Fimages\u002F99f55eef-f487-4620-bf7c-bb25d7b2b074","\u002Fcourses\u002Fpulmonary-function-testing-essentials","1768253388","1553014043","Pulmonary function testing is a pretty niche topic—and it’s about much more than simply looking at computer-generated test results. In this course, you’ll uncover the physiologic basis of pulmonary function testing and its clinical applications. Know when to use spirometry, what additional (and relatively uncommon) tests to consider, and how to use diagnostic algorithms to interpret test results.",{"duration":269,"quizzes":270,"lessons":271},7134,10,42,{"id":273,"name":260,"image":274,"profession":275,"relativeUrl":278,"specializations":279},5729,"https:\u002F\u002Fmedmastery-backend-prod-kjbeds.s3.eu-west-1.amazonaws.com\u002Fmedia\u002Fimages\u002F9c43ceff-d627-4aad-9d2d-ebd3289385bf",{"name":276,"description":277},"Pulmonologist","Michael is Vice Chairman in the Department of Medicine and Associate Professor of Medicine in the Pulmonary, Allergy, and Critical Care Division at the Perelman School of Medicine, University of Pennsylvania, USA.","\u002Fteachers\u002Fmichael-a-grippi-md",[258],172,"3m",[283,309,328],{"id":284,"title":285,"text":286,"image":287,"author":295,"path":303,"readDuration":304,"readDurationFormatted":281,"internal":305},1350,"How to Recognize INOCA (ANOCA) on an Exercise Stress Test ","Angina, abnormal stress test, clean coronaries—that's INOCA (or ANOCA), and it carries real risk. Learn to recognize and report it with exercise stress ECG.",{"alt":288,"title":289,"size":290,"location":292},"Illustration of the heart's coronary vasculature showing large coronary arteries and the extensive network of smaller vessels affected in INOCA (ischemia with nonobstructive coronary arteries).","",{"width":291,"height":291},1200,{"bucket":293,"key":294},"public-drupal-medmastery-assets-production","\u002F2026-05\u002FC17(1)_magazine image_0.png",{"id":296,"title":297,"relativeURL":298,"image":299,"professionLong":300,"profession":301,"weight":261},1563,"Franz Wiesbauer, MD MPH","\u002Fteachers\u002Ffranz-wiesbauer-md-mph","https:\u002F\u002Fmedmastery-backend-prod-kjbeds.s3.eu-west-1.amazonaws.com\u002Fmedia\u002Fimages\u002F9c43cef0-41ee-4005-9e4a-d8711c816401","Franz is the founder and CEO of Medmastery. He is an internist with a specialization in cardiology and a master’s in public health from Johns Hopkins University.",{"name":302},"Internist","\u002Fmagazine\u002Fexercise-stress-ecg-inoca",141,{"created":306,"updated":307,"published":308},1778115738,1778118425,1778118255,{"id":310,"title":311,"text":312,"image":313,"author":319,"path":321,"readDuration":322,"readDurationFormatted":323,"internal":324},1348,"Hyperlipidemia screening: who, when, & what to measure","Testing for hyperlipidemia can help you mitigate your patients' cardiovascular risk. Learn who to screen and when, which measures to request, and how to stratify risk.",{"alt":314,"title":289,"size":315,"location":317},"Lipid panel blood sample tubes used to test for hyperlipidemia in a laboratory setting",{"width":316,"height":316},600,{"bucket":293,"key":318},"\u002F2026-04\u002FC121_magazine image.png",{"id":296,"title":297,"relativeURL":298,"image":299,"professionLong":300,"profession":320,"weight":261},{"name":302},"\u002Fmagazine\u002Ftest-for-hyperlipidemia",246,"5m",{"created":325,"updated":326,"published":327},1777403036,1777572381,1777412421,{"id":329,"title":330,"text":331,"image":332,"author":337,"path":346,"readDuration":347,"readDurationFormatted":348,"internal":349},1347,"Outpatient care for COPD exacerbations","Most acute COPD exacerbations can be managed with outpatient treatment. Learn how to treat mild and moderate COPD exacerbations—and when to escalate care.",{"alt":333,"title":289,"size":334,"location":335},"Older patient using a handheld nebulizer to inhale bronchodilator medication during an acute COPD exacerbation",{"width":316,"height":316},{"bucket":293,"key":336},"\u002F2026-04\u002FC133(4)_ exacerbations_magazine image.png",{"id":338,"title":339,"relativeURL":340,"image":341,"professionLong":342,"profession":343,"weight":345},5365,"Siamak Moayedi, MD","\u002Fteachers\u002Fsiamak-moayedi-md","https:\u002F\u002Fmedmastery-backend-prod-kjbeds.s3.eu-west-1.amazonaws.com\u002Fmedia\u002Fimages\u002F9c43cf02-1064-4074-817b-0eb5de6ded74","Professor and Director of Medical Student Education, University of Maryland and Course Director, Essential and Critical Procedures, Emergency Medicine.",{"name":344},"Emergency medicine physician",1533,"\u002Fmagazine\u002Facute-copd-exacerbation-treatment",191,"4m",{"created":350,"updated":351,"published":352},1776705362,1776710540,1776710541,{"seo":354,"og":356},{"title":355,"description":213},"Measuring diffusing capacity | Medmastery",{"title":355,"description":213,"image":357},{"alt":289,"title":289,"size":358,"location":361},{"width":359,"height":360},1568,836,{"bucket":293,"key":362},"\u002Fmigrated-images\u002FScreen Shot 2018-12-15 at 1.12.16 pm.png",{"id":364,"created":365,"updated":366,"published":365},281,1543411193,1655189586]