[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-317093-105":59,"doc-detail-317093-en":131},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":124,"head_meta":126,"extra_data":128,"updated_unix":130},105,"en","peak-expiratory-flow-rate","Peak Expiratory Flow Rate","","Peak expiratory flow rate (PEFR) measures the volume of air forcefully expelled during a single quick exhalation and helps assess ventilation adequacy and airflow obstruction. Normal PEFR varies by sex, age, and height, with values typically higher in males and taller patients, and decreasing from around the 30–40 years range onward. PEFR is affected by asthma and can also reflect airway obstruction in conditions such as COPD. The document outlines clinical indications, contraindications, a step-by-step technique, and interpretation of asthma severity, including how to monitor response to treatment.",{"@graph":69,"@context":123},[70,84,106],{"@type":71,"itemListElement":72},"BreadcrumbList",[73,77,79,82],{"item":74,"name":75,"@type":76,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":78,"name":9,"@type":76,"position":14},"https://docshare.wps.com/document/",{"item":80,"name":35,"@type":76,"position":81},"https://docshare.wps.com/document/healthcare/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/peak-expiratory-flow-rate/317093/",{"url":83,"name":65,"@type":85,"image":86,"author":91,"headline":65,"publisher":94,"fileFormat":97,"inLanguage":63,"description":67,"dateModified":98,"datePublished":99,"encodingFormat":97,"isAccessibleForFree":100,"interactionStatistic":101},"DigitalDocument",{"url":87,"@type":88,"width":89,"height":90},"https://docshare.wps.com/thumbnails/peak-expiratory-flow-rate/317093.png","ImageObject",300,407,{"name":92,"@type":93},"Eliana","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-10-26","2026-09-20",true,{"@type":102,"interactionType":103,"userInteractionCount":105},"InteractionCounter",{"@type":104},"ViewAction",13,{"@type":107,"mainEntity":108},"FAQPage",[109,115,119],{"name":110,"@type":111,"acceptedAnswer":112},"What does peak expiratory flow rate (PEFR) indicate clinically?","Question",{"text":113,"@type":114},"PEFR is a reliable indicator of ventilation adequacy and airflow obstruction. It is used to assess asthma severity and monitor the effectiveness of bronchodilator therapy.","Answer",{"name":116,"@type":111,"acceptedAnswer":117},"What factors affect normal PEFR values?",{"text":118,"@type":114},"Normal peak flow varies between individuals and depends on sex, age, and height. PEFR is typically higher in males and taller patients and decreases with age after childhood and adolescence.",{"name":120,"@type":111,"acceptedAnswer":121},"How should peak flow be measured to ensure valid results?",{"text":122,"@type":114},"Introduce the procedure, explain it, and obtain consent. Set the meter to zero, stand up, fully breathe out, take a deep breath in with an open mouth, seal lips tightly around the mouthpiece, and blow out hard and fast once; repeat two more times and record the highest of the three readings.","https://schema.org",{"og:url":83,"og:type":125,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":127,"canonical":83},"index,follow",{"doc_id":129,"site_id":62},317093,1790153790,{"code":4,"msg":5,"data":132},{"doc_id":129,"user_id":133,"nickname":92,"user_avatar":134,"doc_module":4,"category_id":34,"category_name":35,"doc_title":65,"doc_description":67,"doc_content":135,"file_id":136,"file_url":137,"file_type":138,"file_size":139,"view_count":105,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":29,"language":140,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":141,"faqs":142,"seo_title":143,"seo_description":67,"update_tm":144,"read_time":145},4398048949847,"https://ap-avatar.wpscdn.com/avatar/400002536579ef2da7f?_k=1778318612642679267","# Peak Expiratory Flow Rate\n\nDr Jason Long,Director of Clinical Skills  \nBackground  \nPeak expiratory flow rate(PEFR)is the volume of air forcefully expelled from thelungs in one quick exhalation,and is a reliable indicator of ventilation adequacy aswell as airflow obstruction.The normal peak flow value can range from person toperson and is dependent upon factors such as sex,age and height.PEFR is typicallyhigher in males than females and higher in taller patients.After expected increasesthrough childhood and adolescence,PEFR decreases with age from 30-40 yearsonwards(see Figure 1).  \nFigure 1  \nAsthma is the most common condition that affects peak flow.However,otherconditions such as Chronic Obstructive Pulmonary Disease (COPD)that cause airwayobstruction can also affect PEFR.  \nAsthma is a chronic condition characterised by exacerbations of airwayhypersensitivity,bronchoconstriction,mucus secretion and inflammation of the lowerairways.An exacerbation of asthma caused by a trigger (for example cold air)resultsin the narrowing of the lower airways,trapping air and resulting in the individualstruggling to exhale.This can lead to a ventilation/perfusion mismatch,hypoxia,hypercapnia and acid-base imbalances,each of which can lead to further potentiallylife-threatening complications if not treated in a timely manner.Peak expiratory flow isa simple and easy,yet essential diagnostic tool used to assess asthma severity.Peakflow is also an important measure of the effectiveness of treatment with bronchodilatortherapy.Peak flow meters(EU/EN ISO standard)are handheld devices used tomeasure PEFR in the ambulatory setting.The differences between Peak Flow Metersand Spirometry are shown in Figure 2.  \nFigure 2  \n## Clinical Indications\n\nIndications for Peak Flow  \nIn the pre-hospital setting,peak flow can be used to assess the severity of anasthma exacerbation).It is also indicated to assess the effects of therapy postnebulisation  \n## Contra-indications:\n\nPatients who are severely short of breath and unable to achieve full inspiration maynot tolerate a peak flow,and in situations where the patient is in severe respiratorydistress,attempting a peak flow may quicken deterioration of their breathing  \nPatients diagnosed with asthma may already have a peak flow meter and undertakedaily readings,logging these on their own personalised charts.Peak flow readings canchange throughout the day therefore patients are advised to record their readings bothmorning and evening.It is important to ascertain what an individual's normal and bestPEFR values are and compare current readings along with the normal values chart  \nMonitoring Peak Flow provides an indication of how well the disease is being managed  \n>Peak flow chart showing recovery from acute asthma with pronounced morning clips  \n## Performing the Procedure\n\nProcedure  \nIntroduce,EXPLAIN,consent  \nAsk the patient to:  \n√Slide the marker down as far as it will go.This sets the meter atzero  \n√Stand up  \n√Breathe out fully  \n√Take a deep breath in with their mouth open  \n√Place the meter in their mouth with their lips forming a tight sealaround the mouthpiece  \n√Keep their fingers away from the markings  \n√Blow out once as hard and fast as they can  \n√Repeat two more times(resetting the marker to zero each time)  \n√Their peak flow is the HIGHEST of these 3 readings  \n## Clinical implications and patient management\n\nDuring an exacerbation of asthma,air becomes trapped due to bronchoconstrictionand inflammation and therefore limits the volume of air exhaled during each breath.This can present with differing levels of severity which can affect peak flow values(seeTable 1).  \nTable 1,Asthma Severity  \n\n| Mild/moderate   | Acute severe   | Life threatening   |\n| --- | --- | --- |\n| ● PEFR >50-75%best  \u003Cbr>or predicted   | Adults:  \u003Cbr>● PEFR 33-50%best or  \u003Cbr>predicted  \u003Cbr>Paediatrics 1 year and  \u003Cbr>over:  \u003Cbr>● PEFR 33-50%best or  \u003Cbr>predicted   | Adults:  \u003Cbr>·PEFR \u003C33%best orr  \u003Cbr>predicted  \u003C","cbCainRn904dfz4F","https://ap.wps.com/l/cbCainRn904dfz4F","pdf",1453411,"English","# Background\n# Clinical Indications\n## Indications for Peak Flow\n# Contra-indications\n# Performing the Procedure\n# Clinical implications and patient management\n# Key Learning Points","[{\"question\":\"What does peak expiratory flow rate (PEFR) indicate clinically?\",\"answer\":\"PEFR is a reliable indicator of ventilation adequacy and airflow obstruction. It is used to assess asthma severity and monitor the effectiveness of bronchodilator therapy.\"},{\"question\":\"What factors affect normal PEFR values?\",\"answer\":\"Normal peak flow varies between individuals and depends on sex, age, and height. PEFR is typically higher in males and taller patients and decreases with age after childhood and adolescence.\"},{\"question\":\"How should peak flow be measured to ensure valid results?\",\"answer\":\"Introduce the procedure, explain it, and obtain consent. Set the meter to zero, stand up, fully breathe out, take a deep breath in with an open mouth, seal lips tightly around the mouthpiece, and blow out hard and fast once; repeat two more times and record the highest of the three readings.\"}]","Peak Expiratory Flow Rate | PDF",1789928658,15]