{"id":495,"date":"2013-03-27T22:46:40","date_gmt":"2013-03-27T22:46:40","guid":{"rendered":"http:\/\/drcrunch.wordpress.com\/?p=495"},"modified":"2013-03-27T22:46:40","modified_gmt":"2013-03-27T22:46:40","slug":"sorry-doctor-the-abg-machine-doesnt-believe-you","status":"publish","type":"post","link":"http:\/\/drcrunch.co.uk\/blog\/2013\/03\/27\/sorry-doctor-the-abg-machine-doesnt-believe-you\/","title":{"rendered":"Sorry doctor, the ABG machine doesn&#8217;t believe you&#8230;"},"content":{"rendered":"<figure id=\"attachment_497\" aria-describedby=\"caption-attachment-497\" style=\"width: 225px\" class=\"wp-caption alignnone\"><a href=\"https:\/\/i0.wp.com\/drcrunch.co.uk\/blog\/wp-content\/uploads\/2013\/03\/2013-03-27-16-31-191.jpg\"><img loading=\"lazy\" decoding=\"async\" data-attachment-id=\"497\" data-permalink=\"http:\/\/drcrunch.co.uk\/blog\/2013\/03\/27\/sorry-doctor-the-abg-machine-doesnt-believe-you\/samsung-16\/\" data-orig-file=\"https:\/\/i0.wp.com\/drcrunch.co.uk\/blog\/wp-content\/uploads\/2013\/03\/2013-03-27-16-31-191.jpg?fit=1920%2C2560\" data-orig-size=\"1920,2560\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;2.64&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;GT-I9000&quot;,&quot;caption&quot;:&quot;SAMSUNG&quot;,&quot;created_timestamp&quot;:&quot;1364401877&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;3.79&quot;,&quot;iso&quot;:&quot;80&quot;,&quot;shutter_speed&quot;:&quot;0.03613777526821&quot;,&quot;title&quot;:&quot;SAMSUNG&quot;,&quot;orientation&quot;:&quot;1&quot;}\" data-image-title=\"Amazing ABG\" data-image-description=\"\" data-medium-file=\"https:\/\/i0.wp.com\/drcrunch.co.uk\/blog\/wp-content\/uploads\/2013\/03\/2013-03-27-16-31-191.jpg?fit=225%2C300\" data-large-file=\"https:\/\/i0.wp.com\/drcrunch.co.uk\/blog\/wp-content\/uploads\/2013\/03\/2013-03-27-16-31-191.jpg?fit=700%2C933\" class=\"size-medium wp-image-497\" alt=\"The most extreme respiratory acidosis ever\" src=\"https:\/\/i0.wp.com\/drcrunch.co.uk\/blog\/wp-content\/uploads\/2013\/03\/2013-03-27-16-31-191.jpg?resize=225%2C300\" width=\"225\" height=\"300\" srcset=\"https:\/\/i0.wp.com\/drcrunch.co.uk\/blog\/wp-content\/uploads\/2013\/03\/2013-03-27-16-31-191.jpg?w=1920 1920w, https:\/\/i0.wp.com\/drcrunch.co.uk\/blog\/wp-content\/uploads\/2013\/03\/2013-03-27-16-31-191.jpg?resize=225%2C300 225w, https:\/\/i0.wp.com\/drcrunch.co.uk\/blog\/wp-content\/uploads\/2013\/03\/2013-03-27-16-31-191.jpg?resize=768%2C1024 768w, https:\/\/i0.wp.com\/drcrunch.co.uk\/blog\/wp-content\/uploads\/2013\/03\/2013-03-27-16-31-191.jpg?resize=700%2C933 700w, https:\/\/i0.wp.com\/drcrunch.co.uk\/blog\/wp-content\/uploads\/2013\/03\/2013-03-27-16-31-191.jpg?w=1400 1400w\" sizes=\"auto, (max-width: 225px) 100vw, 225px\" data-recalc-dims=\"1\" \/><\/a><figcaption id=\"caption-attachment-497\" class=\"wp-caption-text\">Extreme respiratory acidosis<\/figcaption><\/figure>\n<p>This ABG was taken on 15L\/O2 min.<\/p>\n<p>A loose translation:<\/p>\n<p># = uh oh<br \/>\n! = the patient has probably\u00a0arrested in the time it took you to analyse this ABG<br \/>\n? = lol, that&#8217;s not possible.<\/p>\n<p>It came from the left radial artery of a man in his early 70s who was referred by his GP for seeming drowsy and cold with a saturation of 71%.<\/p>\n<p>He had a PMH of COPD (home oxygen) and CCF.<\/p>\n<p>On arrival, he was too drowsy for a history.<\/p>\n<p>On examination, there was use of accessory muscles although he seemed fatigued. There was diffuse wheeze and bilaterally reduced air entry.<\/p>\n<p>The SpR treated it as a severe exacerbation of COPD.<\/p>\n<p><strong>What are the common causes of an <a href=\"http:\/\/www.patient.co.uk\/doctor\/Acute-Exacerbations-of-COPD.htm\" target=\"_blank\">exacerbation of COPD<\/a>?<\/strong><\/p>\n<p>Most community-acquired infections are caused by\u00a0<i>Streptococcus pneumoniae,<\/i>\u00a0<i>Haemophilus influenzae<\/i> and\u00a0<i>Moraxella catarrhalis<\/i>. Staph aureus classically causes pneumonia following influenza infection. There are also viral triggers and pollutants.<\/p>\n<p><strong>\u00a0What is best medical management?<\/strong><\/p>\n<ul>\n<li>initially controlled oxygen to maintain SaO2 88\u201392%<br \/>\n&#8211; <a href=\"http:\/\/www.brit-thoracic.org.uk\/portals\/0\/guidelines\/emergency%20oxygen%20guideline\/appendix%201%20summary%20of%20recommendations.pdf\" target=\"_blank\">adjust target range to 94\u201398%<\/a> if the PaCO2 is normal (unless there is a history of previous NIV or IPPV) and recheck blood gases after 30\u201360 min<\/li>\n<li>nebulised salbutamol 2.5\u20135 mg<\/li>\n<li>nebulised ipratroprium 500 micrograms<\/li>\n<li>prednisolone 30 mg<\/li>\n<li>antibiotic agent (when indicated).<\/li>\n<\/ul>\n<p><strong>What are the management options in COPD with hypercapnic failure?<\/strong><\/p>\n<table width=\"459\" border=\"1\" cellspacing=\"0\" cellpadding=\"0\">\n<tbody>\n<tr>\n<td valign=\"top\" width=\"106\">Hypoxic (pO2 &lt;8kPa)<\/td>\n<td valign=\"top\" width=\"106\">Hypercapnic (pCO2 &gt; 6kPa)<\/td>\n<td valign=\"top\" width=\"106\">Acidotic (pH &lt; 7.35)<\/td>\n<td valign=\"top\" width=\"140\">Treatment<\/td>\n<\/tr>\n<tr>\n<td valign=\"top\" width=\"106\">No<\/td>\n<td valign=\"top\" width=\"106\">No<\/td>\n<td valign=\"top\" width=\"106\">No<\/td>\n<td valign=\"top\" width=\"140\">Medical management<\/td>\n<\/tr>\n<tr>\n<td valign=\"top\" width=\"106\">Yes<\/td>\n<td valign=\"top\" width=\"106\">No<\/td>\n<td valign=\"top\" width=\"106\">No<\/td>\n<td valign=\"top\" width=\"140\">Increase inspired O2<br \/>\nTarget sats: 94-98%<\/td>\n<\/tr>\n<tr>\n<td valign=\"top\" width=\"106\">Yes<\/td>\n<td valign=\"top\" width=\"106\">Yes<\/td>\n<td valign=\"top\" width=\"106\">No<\/td>\n<td valign=\"top\" width=\"140\">Titrate O2 down if pO2 &gt; 8kPa.<br \/>\nTarget sats: 88-92%<\/td>\n<\/tr>\n<tr>\n<td valign=\"top\" width=\"106\">Yes<\/td>\n<td valign=\"top\" width=\"106\">Yes<\/td>\n<td valign=\"top\" width=\"106\">Yes<\/td>\n<td valign=\"top\" width=\"140\">NIV or intubation. May need discussion with ITU.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><strong>What are the <a href=\"http:\/\/www.rcplondon.ac.uk\/sites\/default\/files\/concise-niv-in-copd-2008.pdf\">five factors<\/a> that need to assessed before starting NIV?<\/strong><\/p>\n<ul>\n<li>their pre-morbid state<\/li>\n<li>the severity of the physiological disturbance<\/li>\n<li>the reversibility of the acute illness<\/li>\n<li>the presence of relative contraindications (see Table 1), <i>and <\/i><\/li>\n<li>where possible, the patient&#8217;s wishes.<\/li>\n<\/ul>\n<p>The ideal COPD\/NIV candidate is a well-informed, compliant patient who is able to protect his own airway. He has a reversible COPD exacerbation, and enjoyed good pre-morbid health. His pH is between 7.25 and 7.35 (if pH &lt;7.25 invasive ventilation may be more appropriate), his pCO2 &gt; 6kPa and he is moderately hypoxic (severe hypoxia is an indication for invasive ventilation).<\/p>\n<p>The contraindications are listed below:<\/p>\n<ul>\n<li>Life-threatening hypoxaemia<\/li>\n<li>Severe co-morbidity<\/li>\n<li>Confusion\/agitation\/severe cognitive impairment<\/li>\n<li>Facial burns\/trauma\/recent facial or upper airway surgery<\/li>\n<li>Vomiting<\/li>\n<li>Fixed upper airway obstruction<\/li>\n<li>Undrained pneumothorax<\/li>\n<li>Upper gastrointestinal surgery<\/li>\n<li>Inability to protect the airway<\/li>\n<li>Copious respiratory secretions<\/li>\n<li>Haemodynamically unstable requiring inotropes\/pressors (unless in a critical care unit)<\/li>\n<li>Patient moribund<\/li>\n<li>Bowel obstruction<\/li>\n<\/ul>\n<p>Having assessed the five criteria above, you should be able to reach a decision about what treatment options are suitable for this patient:<\/p>\n<ul>\n<li>requiring immediate intubation and ventilation<\/li>\n<li>suitable for NIV and suitable for escalation to intensive care treatment\/ intubation and ventilation \u2028if required<\/li>\n<li>suitable for NIV but not suitable for escalation to intensive care treatment\/ intubation and ventilation<\/li>\n<li>not suitable for NIV but for full active medical management<\/li>\n<li>palliative care agreed as most appropriate management<\/li>\n<\/ul>\n<p>I will find out more about NIV from the respiratory team and write up any clinical pearls they have in the next post.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>This ABG was taken on 15L\/O2 min. A loose translation: # = uh oh ! = the patient has probably\u00a0arrested in the time it took you to analyse this ABG&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"spay_email":"","footnotes":"","jetpack_publicize_message":""},"categories":[1],"tags":[],"class_list":["post-495","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"jetpack_featured_media_url":"","jetpack_publicize_connections":[],"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p9zRNY-7Z","jetpack_likes_enabled":true,"jetpack-related-posts":[],"_links":{"self":[{"href":"http:\/\/drcrunch.co.uk\/blog\/wp-json\/wp\/v2\/posts\/495","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/drcrunch.co.uk\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/drcrunch.co.uk\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/drcrunch.co.uk\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/drcrunch.co.uk\/blog\/wp-json\/wp\/v2\/comments?post=495"}],"version-history":[{"count":0,"href":"http:\/\/drcrunch.co.uk\/blog\/wp-json\/wp\/v2\/posts\/495\/revisions"}],"wp:attachment":[{"href":"http:\/\/drcrunch.co.uk\/blog\/wp-json\/wp\/v2\/media?parent=495"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/drcrunch.co.uk\/blog\/wp-json\/wp\/v2\/categories?post=495"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/drcrunch.co.uk\/blog\/wp-json\/wp\/v2\/tags?post=495"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}