{"id":4696,"date":"2025-08-14T20:42:37","date_gmt":"2025-08-15T00:42:37","guid":{"rendered":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/?post_type=chapter&p=4696"},"modified":"2025-12-07T23:24:07","modified_gmt":"2025-12-08T04:24:07","slug":"asthma-attack-pathophysiology-and-consequences","status":"web-only","type":"chapter","link":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/chapter\/asthma-attack-pathophysiology-and-consequences\/","title":{"raw":"6p14 Asthma Attack: Pathophysiology and Consequences","rendered":"6p14 Asthma Attack: Pathophysiology and Consequences"},"content":{"raw":"

What is the Pathophysiology of an Asthmatic Attack?\u00a0 and what are the Consequences?<\/strong><\/h2>\r\n

Initial Response \u2013 Respiratory Alkalosis:<\/strong><\/h1>\r\n
    \r\n \t
  • Hyperventilation<\/strong>\u00a0occurs during an asthma attack.<\/li>\r\n \t
  • Causes blood to become\u00a0more basic (alkaline)<\/strong>, leading to\u00a0respiratory alkalosis<\/strong>\u00a0(blood pH rises above 7.45).<\/li>\r\n \t
  • Why?<\/strong>\r\n
      \r\n \t
    • During hyperventilation, excessive CO\u2082 is expelled from the lungs.<\/li>\r\n \t
    • CO\u2082 in blood exists in equilibrium with carbonic acid, hydrogen ions, and bicarbonate.<\/li>\r\n \t
    • Rapid breathing shifts this equilibrium, decreasing CO\u2082 and carbonic acid.<\/li>\r\n \t
    • Less carbonic acid means fewer hydrogen ions (H\u207a), raising blood pH.<\/li>\r\n \t
    • This initial phase is typically\u00a0alkalotic<\/strong>\u00a0due to excess breathing out of CO\u2082.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n

      Progression \u2013 Trapped CO\u2082 and Respiratory Acidosis:<\/strong><\/h1>\r\n
        \r\n \t
      • Due to\u00a0air trapping<\/strong>\u00a0from mucus plugs and bronchoconstriction, CO\u2082 cannot be expelled efficiently.<\/li>\r\n \t
      • CO\u2082 accumulates in the alveoli and blood, shifting the equilibrium:\r\n
          \r\n \t
        • Increased CO\u2082 raises carbonic acid levels.<\/li>\r\n \t
        • More carbonic acid dissociates into hydrogen ions and bicarbonate.<\/li>\r\n \t
        • Elevated H\u207a ions lower blood pH, resulting in\u00a0respiratory acidosis<\/strong>.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n

          Impact on Blood Gas Levels:<\/strong><\/h1>\r\n
            \r\n \t
          • Hypoxia:<\/strong>\u00a0Reduced oxygen levels in blood.<\/li>\r\n \t
          • Hypercapnia:<\/strong>\u00a0Increased CO\u2082 (carbonic acid).<\/li>\r\n \t
          • Blood becomes more acidic, impairing cellular function and organ performance.<\/li>\r\n<\/ul>\r\n

            Severe Respiratory Distress:<\/strong><\/h2>\r\n
              \r\n \t
            • Continued hypoventilation leads to:\r\n
                \r\n \t
              • Critical hypoxemia (arterial oxygen partial pressure <50 mm Hg).<\/li>\r\n \t
              • Organ dysfunction due to inadequate oxygen supply and acidosis.<\/li>\r\n \t
              • Cellular and tissue damage, potentially leading to organ failure.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n

                Signs and Symptoms of Low Oxygen:<\/strong><\/h1>\r\n
                  \r\n \t
                • Anxiety, confusion, decreased responsiveness.<\/li>\r\n \t
                • Cyanosis (blue lips, fingertips, toes).<\/li>\r\n \t
                • Altered mental state, possible coma.<\/li>\r\n<\/ul>\r\n

                  Status Asthmaticus:<\/strong><\/h1>\r\n
                    \r\n \t
                  • A\u00a0persistent severe asthma attack<\/strong>\u00a0unresponsive to inhalers.<\/li>\r\n \t
                  • Requires emergency medical intervention (911).<\/li>\r\n \t
                  • Progression includes:\r\n
                      \r\n \t
                    • Severe hypoxia<\/strong>.<\/li>\r\n \t
                    • Acidosis<\/strong>\u00a0from CO\u2082 retention.<\/li>\r\n \t
                    • Enzymatic and cellular dysfunction.<\/li>\r\n \t
                    • Cardiac arrhythmias and neural depression.<\/li>\r\n \t
                    • Loss of responsiveness, potential respiratory and cardiac arrest.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n

                      Summary:<\/strong><\/h1>\r\nDuring an asthma attack, hyperventilation initially causes respiratory alkalosis, but airway obstruction quickly traps CO\u2082, leading to respiratory acidosis. If the attack persists and progresses, severe hypoxia, acidosis, and organ failure may occur. In critical cases like status asthmaticus, immediate emergency treatment is vital to prevent death.","rendered":"

                      What is the Pathophysiology of an Asthmatic Attack?\u00a0 and what are the Consequences?<\/strong><\/h2>\n

                      Initial Response \u2013 Respiratory Alkalosis:<\/strong><\/h1>\n
                        \n
                      • Hyperventilation<\/strong>\u00a0occurs during an asthma attack.<\/li>\n
                      • Causes blood to become\u00a0more basic (alkaline)<\/strong>, leading to\u00a0respiratory alkalosis<\/strong>\u00a0(blood pH rises above 7.45).<\/li>\n
                      • Why?<\/strong>\n
                          \n
                        • During hyperventilation, excessive CO\u2082 is expelled from the lungs.<\/li>\n
                        • CO\u2082 in blood exists in equilibrium with carbonic acid, hydrogen ions, and bicarbonate.<\/li>\n
                        • Rapid breathing shifts this equilibrium, decreasing CO\u2082 and carbonic acid.<\/li>\n
                        • Less carbonic acid means fewer hydrogen ions (H\u207a), raising blood pH.<\/li>\n
                        • This initial phase is typically\u00a0alkalotic<\/strong>\u00a0due to excess breathing out of CO\u2082.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n

                          Progression \u2013 Trapped CO\u2082 and Respiratory Acidosis:<\/strong><\/h1>\n
                            \n
                          • Due to\u00a0air trapping<\/strong>\u00a0from mucus plugs and bronchoconstriction, CO\u2082 cannot be expelled efficiently.<\/li>\n
                          • CO\u2082 accumulates in the alveoli and blood, shifting the equilibrium:\n
                              \n
                            • Increased CO\u2082 raises carbonic acid levels.<\/li>\n
                            • More carbonic acid dissociates into hydrogen ions and bicarbonate.<\/li>\n
                            • Elevated H\u207a ions lower blood pH, resulting in\u00a0respiratory acidosis<\/strong>.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n

                              Impact on Blood Gas Levels:<\/strong><\/h1>\n
                                \n
                              • Hypoxia:<\/strong>\u00a0Reduced oxygen levels in blood.<\/li>\n
                              • Hypercapnia:<\/strong>\u00a0Increased CO\u2082 (carbonic acid).<\/li>\n
                              • Blood becomes more acidic, impairing cellular function and organ performance.<\/li>\n<\/ul>\n

                                Severe Respiratory Distress:<\/strong><\/h2>\n
                                  \n
                                • Continued hypoventilation leads to:\n
                                    \n
                                  • Critical hypoxemia (arterial oxygen partial pressure <50 mm Hg).<\/li>\n
                                  • Organ dysfunction due to inadequate oxygen supply and acidosis.<\/li>\n
                                  • Cellular and tissue damage, potentially leading to organ failure.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n

                                    Signs and Symptoms of Low Oxygen:<\/strong><\/h1>\n
                                      \n
                                    • Anxiety, confusion, decreased responsiveness.<\/li>\n
                                    • Cyanosis (blue lips, fingertips, toes).<\/li>\n
                                    • Altered mental state, possible coma.<\/li>\n<\/ul>\n

                                      Status Asthmaticus:<\/strong><\/h1>\n
                                        \n
                                      • A\u00a0persistent severe asthma attack<\/strong>\u00a0unresponsive to inhalers.<\/li>\n
                                      • Requires emergency medical intervention (911).<\/li>\n
                                      • Progression includes:\n
                                          \n
                                        • Severe hypoxia<\/strong>.<\/li>\n
                                        • Acidosis<\/strong>\u00a0from CO\u2082 retention.<\/li>\n
                                        • Enzymatic and cellular dysfunction.<\/li>\n
                                        • Cardiac arrhythmias and neural depression.<\/li>\n
                                        • Loss of responsiveness, potential respiratory and cardiac arrest.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n

                                          Summary:<\/strong><\/h1>\n

                                          During an asthma attack, hyperventilation initially causes respiratory alkalosis, but airway obstruction quickly traps CO\u2082, leading to respiratory acidosis. If the attack persists and progresses, severe hypoxia, acidosis, and organ failure may occur. In critical cases like status asthmaticus, immediate emergency treatment is vital to prevent death.<\/p>\n","protected":false},"author":1370,"menu_order":15,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":["zoe-soon"],"pb_section_license":"cc-by-nc-sa"},"chapter-type":[],"contributor":[60],"license":[57],"class_list":["post-4696","chapter","type-chapter","status-web-only","hentry","contributor-zoe-soon","license-cc-by-nc-sa"],"part":47,"_links":{"self":[{"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/pressbooks\/v2\/chapters\/4696","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/wp\/v2\/users\/1370"}],"version-history":[{"count":4,"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/pressbooks\/v2\/chapters\/4696\/revisions"}],"predecessor-version":[{"id":5307,"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/pressbooks\/v2\/chapters\/4696\/revisions\/5307"}],"part":[{"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/pressbooks\/v2\/parts\/47"}],"metadata":[{"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/pressbooks\/v2\/chapters\/4696\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/wp\/v2\/media?parent=4696"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/pressbooks\/v2\/chapter-type?post=4696"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/wp\/v2\/contributor?post=4696"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/wp\/v2\/license?post=4696"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}