{"id":120864,"date":"2023-10-01T17:56:05","date_gmt":"2023-10-01T17:56:05","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=120864"},"modified":"2023-10-01T17:56:07","modified_gmt":"2023-10-01T17:56:07","slug":"nrnp-6566-week-11-final-exam-study-guide-2023-2024-verified","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2023\/10\/01\/nrnp-6566-week-11-final-exam-study-guide-2023-2024-verified\/","title":{"rendered":"NRNP 6566 WEEK 11 FINAL EXAM STUDY GUIDE 2023 \/ 2024 | Verified"},"content":{"rendered":"\n

NRNP 6566 WEEK 11 FINAL EXAM STUDY GUIDE
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!<\/p>\n\n\n\n

    \n
  1. Interpret arterial blood gases (ABG). Differentiate alkalosis\/ acidosis
    and respiratory \/ metabolic<\/li>\n\n\n\n
  2. Identify a ventilation \u2013 perfusion mismatch and how to treat it
    If there is a mismatch between the alveolar ventilation and the alveolar
    blood flow, this will be seen in the V\/Q ratio. If the V\/Q ratio reduces due
    to inadequate ventilation, gas exchange within the affected alveoli will
    be impaired. As a result, the capillary partial pressure of oxygen (pO2)
    falls and the partial pressure of carbon dioxide (pCO2) rises.
    To manage this, hypoxic vasoconstriction causes blood to be diverted to
    better ventilated parts of the lung. However, in most physiological states
    the hemoglobin in these well-ventilated alveolar capillaries will already
    be saturated. This means that red cells will be unable to bind additional
    oxygen to increase the pO2. As a result, the pO2 level of the blood<\/li>\n<\/ol>\n\n\n\n

    remains low, which acts as a stimulus to cause hyperventilation, resulting
    in either normal or low CO2 levels.
    A mismatch in ventilation and perfusion can arise due to either reduced
    ventilation of part of the lung or reduced perfusion.
    Ventilation\/perfusion mismatch \u2014 Mechanical ventilation can alter two
    opposing forms of ventilation\/perfusion mismatch (V\/Q mismatch), dead
    space (areas that are overventilated relative to perfusion; V>Q) and
    shunt (areas that are underventilated relative to perfusion; V<Q). By
    increasing ventilation (V), the institution of positive pressure ventilation
    will worsen dead space but improve shunt.
    Increased dead space \u2014 Dead space reflects the surface area within the
    lung that is not involved in gas exchange. It is the sum of the anatomic
    plus alveolar dead space. Alveolar dead space (also known as physiologic
    dead space) consists of alveoli that are not involved in gas exchange due
    to insufficient perfusion (ie, overventilated relative to perfusion).
    Positive pressure ventilation tends to increase alveolar dead space by
    increasing ventilation in alveoli that do not have a corresponding
    increase in perfusion, thereby worsening V\/Q mismatch and
    hypercapnia.
    Reduced shunt \u2014 An intraparenchymal shunt exists where there is blood
    flow through pulmonary parenchyma that is not involved in gas
    exchange because of insufficient alveolar ventilation. Patients with
    respiratory failure frequently have increased intraparenchymal shunting
    due to areas of focal atelectasis that continue to be perfused (ie, regions
    that are underventilated relative to perfusion). Treating atelectasis with
    positive pressure ventilation can reduce intraparenchymal shunting by
    improving alveolar ventilation, thereby improving V\/Q matching and
    oxygenation.
    This is particularly true if PEEP is added. (See “Positive end-expiratory
    pressure (PEEP)” and “Measures of oxygenation and mechanisms of
    hypoxemia”, section on ‘V\/Q mismatch’.)<\/p>\n\n\n\n

      \n
    1. Be able to calculate an Aa gradient. Be able to interpret an Aa gradient.
      The alveolar to arterial (A-a) oxygen gradient is a common measure of
      oxygenation (“A” denotes alveolar and “a” denotes arterial
      oxygenation). It is the difference between the amount of the oxygen in
      the alveoli (ie, the alveolar oxygen tension [PAO2]) and the amount of
      oxygen dissolved in the plasma (PaO2):
      A-a oxygen gradient = PAO2 – PaO2
      PaO2 is measured by arterial blood gas, while PAO2 is calculated using the
      alveolar gas equation:
      PAO2 = (FiO2 x [Patm – PH2O]) – (PaCO2 \u00f7 R)<\/li>\n<\/ol>\n\n\n\n

      where FiO2 is the fraction of inspired oxygen (0.21 at room air), Patm is
      the atmospheric pressure (760 mmHg at sea level), PH2O is the partial
      pressure of water (47 mmHg at 37\u00baC), PaCO2 is the arterial carbon
      dioxide tension, and R is the respiratory quotient. The respiratory
      quotient is approximately 0.8 at steady state, but varies according to the
      relative utilization of carbohydrate, protein, and fat.
      The A-a gradient calculated using this alveolar gas equation may deviate
      from the true gradient by up to 10 mmHg. This reflects the equation’s
      simplification from the more rigorous full calculation and the imprecision
      of several independent variables (eg, FiO2 and R).
      The normal A-a gradient varies with age and can be estimated from the
      following equation, assuming the patient is breathing room air:
      A-a gradient = 2.5 + 0.21 x age in years
      The A-a gradient increases with higher FiO2. When a patient receives a
      high FiO2, both PAO2 and PaO2 increase. However, the PAO2 increases
      disproportionately, causing the A-a gradient to increase. In one series,
      the A-a gradient in men breathing air and 100 percent oxygen varied
      from 8 to 82 mmHg in patients younger than 40 years of age and from 3
      to 120 mmHg in patients older than 40 years of age [5].
      Proper determinations of the A-a gradient require exact measurement of
      FiO2 such as when patients are breathing room air or are receiving
      mechanical ventilation. The FiO2 of patients receiving supplemental
      oxygen by nasal cannula or mask can be estimated and the A-a gradient
      approximated but large variations may exist and the A-a gradient may
      substantially vary from the predicted, limiting its usefulness. The use of a
      100 percent non-rebreathing mask reasonably approximates actual
      delivery of 100 percent oxygen and can be used to measure shunt.
      Why use the Aa gradient:
      \u25aa The A-a Gradient can help determine the cause of
      hypoxia; it pinpoints the location of the hypoxia as intraor extra- pulmonary.
      When to use the Aa gradient:
      \u25aa Patients with unexplained hypoxia.
      \u25aa Patients with hypoxia exceeding the degree of their
      clinical illness.<\/p>\n\n\n\n

        \n
      1. Identify clinical symptoms or conditions indicating a need to intubate
        and ventilate a patient
        Neuromuscular depression or failure
        A. Drugs
        Opiods
        Sedatives
        NM Blockers
        B. Trauma
        Spinal Cord injury
        Phrenic nerve injury
        C. Disease
        Guillain Barre syndrome<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"

        NRNP 6566 WEEK 11 FINAL EXAM STUDY GUIDE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! remains low, which acts as a stimulus to cause hyperventilation, resultingin either normal or low CO2 levels.A mismatch in ventilation and perfusion can arise due to either reducedventilation of part of the lung or reduced perfusion.Ventilation\/perfusion mismatch \u2014 Mechanical ventilation can alter twoopposing forms of ventilation\/perfusion mismatch […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[25],"tags":[],"class_list":["post-120864","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/120864","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/comments?post=120864"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/120864\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=120864"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=120864"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=120864"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}