1.7 When and why is an ABG required? 1 To establish a diagnosis The ABG is integral to the diagnosis of respiratory failure and primary hyperventilation. It also identifies the presence of metabolic acidosis and alkalosis. 2 To assess illness severity The four ABG values shown in the table below, in addition to overall clinical assessment, may help identify critically unwell patients requiring urgent intervention. PaO2< 8 kPa Below 8 kPa, falls in PaO2 produce a marked reduction in SaO2 (the ‘steep’ part of the O2 dissociation curve) and hence O2 content of blood Rising PaCO2 Since renal compensation occurs over days to weeks, acute rises in PaCO2 produce a corresponding drop in pH. In respiratory distress, rising PaCO2 often signifies exhaustion and is an ominous sign. Patients require urgent reversal of the process, leading to ventilatory failure or assisted ventilation BE < –10/HCO3< 15 This value is included in several severity scoring systems and, when due to lactic acidosis, indicates severe hypoxia at cellular level H+ > 55/pH < 7.25 A significant decrease in pH outside the normal range indicates that compensatory mechanisms have been overwhelmed and is a medical emergency Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: Common ABG values ABG sampling technique Making ABG interpretation easy Acid–base balance: the basics Stay updated, free articles. Join our Telegram channel Join Tags: Arterial Blood Gases Made Easy Dec 18, 2016 | Posted by admin in CARDIOLOGY | Comments Off on When and why is an ABG required? Full access? Get Clinical Tree
1.7 When and why is an ABG required? 1 To establish a diagnosis The ABG is integral to the diagnosis of respiratory failure and primary hyperventilation. It also identifies the presence of metabolic acidosis and alkalosis. 2 To assess illness severity The four ABG values shown in the table below, in addition to overall clinical assessment, may help identify critically unwell patients requiring urgent intervention. PaO2< 8 kPa Below 8 kPa, falls in PaO2 produce a marked reduction in SaO2 (the ‘steep’ part of the O2 dissociation curve) and hence O2 content of blood Rising PaCO2 Since renal compensation occurs over days to weeks, acute rises in PaCO2 produce a corresponding drop in pH. In respiratory distress, rising PaCO2 often signifies exhaustion and is an ominous sign. Patients require urgent reversal of the process, leading to ventilatory failure or assisted ventilation BE < –10/HCO3< 15 This value is included in several severity scoring systems and, when due to lactic acidosis, indicates severe hypoxia at cellular level H+ > 55/pH < 7.25 A significant decrease in pH outside the normal range indicates that compensatory mechanisms have been overwhelmed and is a medical emergency Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: Common ABG values ABG sampling technique Making ABG interpretation easy Acid–base balance: the basics Stay updated, free articles. Join our Telegram channel Join Tags: Arterial Blood Gases Made Easy Dec 18, 2016 | Posted by admin in CARDIOLOGY | Comments Off on When and why is an ABG required? Full access? Get Clinical Tree
