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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},"Using the nitrogen washout test","Master the use of the nitrogen washout test when assessing small airway function in your patients.",{"id":215,"name":216},1,"Course previews",[218,228,233,238,245],{"type":219,"data":220},"video",{"readDurationInSeconds":221,"video":222},269,{"platform":223,"name":212,"url":224,"size":225},"YouTube","https:\u002F\u002Fwww.youtube.com\u002Fwatch?v=X927Ie3QUBs",{"width":226,"height":227},200,113,{"type":229,"data":230},"free_text",{"readDurationInSeconds":231,"text":232},7.733333333333333,"\u003Cp>In this video, from our Pulmonary Function Testing Essentials course, you'll learn all about the nitrogen washout test and the concept of closing volume when assessing small airway function in your patients.\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},103.46666666666667,"Video Transcript","\u003Cp dir=\"ltr\">\u003Cstrong>[00:00:00] \u003C\u002Fstrong>Exhaled gas concentrations can also provide information on the uniformity of inspired gas distribution throughout the lungs. When we exhale, the concentration of gases in the expirate changes from beginning to end of expiration. If a gas is distributed non-uniformly throughout the lungs, the changes and concentration of the gas, throughout expiration, will be greater than normal. \u003C\u002Fp>\u003Cp dir=\"ltr\">\u003Cstrong>[00:00:30]\u003C\u002Fstrong> The single-breath nitrogen washout test is based on this hypothesis. The seated patient takes two breaths of air and exhales to residual volume. Then, the valve on the mouthpiece, is turned to administer 100% oxygen. The patient takes a deep breath of the oxygen to total lung capacity and then exhales slowly to residual volume. The concentration of nitrogen in the expired \u003C\u002Fp>\u003Cp dir=\"ltr\">\u003Cstrong>[00:01:00]\u003C\u002Fstrong> gas is measured continuously using a nitrogen meter. Additionally, exhaled volume is measured using a pneumotachograph. A plot of exhaled nitrogen concentration versus exhaled volume is generated. A typical plot appears as follows: four relatively discrete phases of the curve, I, II, III, and IV are depicted. Phase \u003C\u002Fp>\u003Cp dir=\"ltr\">\u003Cstrong>[00:01:30]\u003C\u002Fstrong> one represents the initial portion of the expirate, which is devoid of nitrogen, since pure oxygen was inhaled during the previous breath. This portion represents gas, residing in the proximal airways, from the end of the prior inspiration. Phase two constitutes a mixture of gas, from the central airways and the alveoli. Phase three is defined by a mixture of gases from the lung apices, mid lung zones, \u003C\u002Fp>\u003Cp dir=\"ltr\">\u003Cstrong>[00:02:00] \u003C\u002Fstrong>and lung bases. And phase four constitutes gas arising predominantly from the apices, as the airways at the bases close, as lower lung volumes are approached. With inspiration, most inspired gas goes to the bases where there are more alveoli and where the alveoli are less distended than those in the apices, and hence, can expand more. As a result, \u003C\u002Fp>\u003Cp dir=\"ltr\">\u003Cstrong>[00:02:30] \u003C\u002Fstrong>the inhaled pure oxygen is primarily distributed to the bases, diluting the nitrogen in that region and accounting for a concentration difference in nitrogen between the apices and the bases. During exhalation, the decreased elastic recoil of the lung and narrowing of small airways cause closure of small airways at the bases of the lungs. As this happens, the contribution of gas from \u003C\u002Fp>\u003Cp dir=\"ltr\">\u003Cstrong>[00:03:00]\u003C\u002Fstrong> basilar alveoli to the expired gas concentration decreases. And as exhalation progresses, more exhaled gas comes from the apices, which represent the less diluted alveolar air, which is higher in nitrogen concentration. The exhaled volume from the onset of phase four, to the end of the expiratory maneuver, is known as closing volume. Remember, this is the \u003C\u002Fp>\u003Cp dir=\"ltr\">\u003Cstrong>[00:03:30] \u003C\u002Fstrong>portion of the exhaled air after the closure of the small airways so a change in this value reflects changes in the small airways. Normal closing volume is about 10% of vital capacity. With small airways disease, aging, premature closure of airways, or cigarette smoking, closing volume is increased. In patients greater than 50 years of age, closing volume may be \u003C\u002Fp>\u003Cp dir=\"ltr\">\u003Cstrong>[00:04:00]\u003C\u002Fstrong> 25% of vital capacity.\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],138,"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},"Using the nitrogen washout test | Medmastery",{"title":355,"description":213,"image":357},{"alt":289,"title":289,"size":358,"location":361},{"width":359,"height":360},1540,842,{"bucket":293,"key":362},"\u002Fmigrated-images\u002FScreen Shot 2018-12-15 at 1.09.28 pm.png",{"id":364,"created":365,"updated":366,"published":365},280,1543151757,1655189586]