Gas Exchange PDF

TOBI AJAYI GAS EXCHANGE  LEARNING OBJECTIVES Review of Pathophysiology & Pathophysiology & respiratory system Pharmacology of Pharmacology of physiology Asthma...

TOBI AJAYI GAS EXCHANGE  LEARNING OBJECTIVES Review of Pathophysiology & Pathophysiology & respiratory system Pharmacology of Pharmacology of physiology Asthma COPD  if there is too much Co2 in the blood it makes the blood acidic THE ROLE OF THE RESPIRATORY SYSTEM The role of the respiratory system, is to move air into the body and remove waste products. Body cells require oxygen for respiration. The network of respiratory organs and eventual gas exchange into the blood, enables the oxygen we breathe to reach our body cells. In turn, carbon dioxide is exhaled.  PARTS OF THE RESPIRATORY SYSTEM Functionally, the air passages of the respiratory system can be divided into 2 parts: The conducting airways: through which air moves between the lungs and atmosphere. (Nasal passages, mouth and nasopharynx, larynx, and the tracheobronchial tree). gets filtered, warmed, and moisturized The respiratory airway: The lungs are the functional structures of the respiratory system. Lobules are the smallest functional unit of the lungs, consisting of the respiratory bronchioles, alveoli, and pulmonary capillaries, responsible for gas exchange.  NASAL CAVITY & THE MOUTH Text Air is inhaled and enters the body through the mouth and nasal cavity. It is warmed up through this process.  TRACHEA The air passes down the trachea. The trachea is a long tube connecting the mouth and nasal cavity to the rest of the respiratory system.  BRONCHUS The trachea branches off into two bronchi. One bronchus enters each lung.  BRONCHIOLES Each bronchus divides into smaller tubes called bronchioles, which the air passes through.  ALVEOLI Alveoli are located at the end of each bronchiole. Alveoli are air sacs which facilitate gas exchange. There are millions of them in the lungs. Alveolar macrophages are responsible for removal of offending particles from the alveoli. aveoli are very vascular… when oxygen comes into aveoli it diffuses ALVEOLI FEATURES GAS EXCHANGE IN They have thin walls to reduce the distance for diffusion. The walls are only one cell thick. They have THE ALVEOLI a large surface area which is moist so gases can dissolve and diffuse across. They are surrounded by capillaries, so alveoli have a rich blood supply. GAS EXCHANGE CO2 out oxygen Inhaled oxygen diffuses from the alveoli into the diffuses into blood. Carbon dioxide diffuses from the blood into blood stream the alveoli to be exhaled. aveoli has lots of surface area =lots of area to do gas exchange  PLEURA The pleura is a double-layered membrane that surrounds each lung, consisting of: Visceral pleura: which adheres to the lung surface both of these rub against each other but it is protective so it doesnt rub against ribs Parietal pleura: which lines the chest wall. The pleural cavity is the thin space between the both pleura. It contains a thin film of serous fluid that reduces friction during respiration, but is also a potential space for excess fluid or inflammatory exudates to accumulate (Pleural effusion). not able to expand lungs = SOB VENTILATION Ventilation: movement of gasses in and out of the lungs. Inspiration: air moves into the lungs as respiratory muscles expand the chest cavity. Expiration: air moves out of the lungs as the chest muscles recoil and chest cavity becomes smaller. The lung tissue is made of elastin and collagen fibers. When elastin fibers are replaced by scar tissue (e.g. pulmonary fibrosis), the lungs become stiff and non-compliant. Pulmonary congestion and edema also result in a reversible decrease in pulmonary compliance ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) PULMONARY FUNCTION TESTS It is about 80 percent of total capacity, or 4.8 liters, because some air remains in your lungs after you exhale Spirometry is a physiological test that measures the ability Forced Vital Capacity (FVC) to inhale and exhale air relative Maximum amount of air that to time. Spirometry is a can be rapidly and forcefully diagnostic test of several exhaled from the lungs after common respiratory diseases full inspiration Forced Expiratory Volume in Percentage of FVC 1 second (FEV-1.0) Volume of air expired in the first second, expressed as a percentage of FVC Volume of air expired in the first second of FVC just know that ratio of FEV a little but of air always remains in ur -1.0 : FVC is used for lungs when u inhale and diganostic purposes  PERFUSION Lung perfusion refers to the flow of blood through the blood vessels in the lungs. It is essential for the exchange of oxygen and carbon dioxide: As blood flows through the lungs, it picks up oxygen from the air we breathe and releases carbon dioxide to be exhaled. The ventilation-perfusion (V/Q) ratio is a simple way to understand how well the lungs are getting oxygen into the blood and removing carbon dioxide. It compares two things: Ventilation (V): The amount of air reaching the alveoli (tiny air sacs in the lungs where gas exchange happens). Ventilation-Perfusion Ration (V/Q): Perfusion (Q): The amount of blood flowing to the alveoli. For efficient gas exchange, the air reaching the alveoli should match the blood flowing around compares the amount of air that gets into the lungs (ventilation) to the amount of blood them. Ideally, the V/Q ratio is close to 1, meaning air flow and blood flow are balanced. flowing through the lungs (perfusion), to assess how well the lungs are bringing in oxygen and getting rid of carbon dioxide. In healthy lungs, the V/Q ratio is typically around 0.8, meaning there is slightly more blood flow than air reaching the alveoli. Conditions like pneumonia can make it hard for air to get in, while a blood clot in the lung can block blood flow, both affecting the V/Q ratio and overall lung function. A V/Q ratio of 0.8 means that there is slightly less ventilation compared to perfusion. In other words, the amount of air reaching the alveoli is a bit less than the amount of blood flowing through the pulmonary capillaries around the alveoli.  DIFFUSION Diffusion: movement of gasses between the lungs and the blood (alveolar-capillary membrane). When you breathe in, oxygen from the air enters the alveoli. Due to a difference in concentration (more oxygen in the alveoli than in the blood), oxygen diffuses into the blood. At the same time, carbon dioxide, which is in higher concentration in the blood, diffuses from the blood into the alveoli to be exhaled. Diffusion is affected by: Characteristics of gas (e.g. co2 is diffuses 20x faster than O2). Concentration of gas ( differences in partial pressure on either side of the membrane). thickness of alveolar-capillary membrane. Surface area of lung tissue (diseases that destroy lung reduce surface area and diffusion).  Checking Oxygen Levels (PaO₂): Nurses look at the ) ) ) ) ) ) ) ) ) oxygen level in the blood. If it’s low, the patient might need ARTERIAL BLOOD GASES ) ) ) ) ) ) ) ) ) more oxygen to help them breathe better. Seeing How Well the Patient is Breathing Out CO₂ (PaCO₂): This shows how well a patient is getting rid of carbon dioxide. If CO₂ is too high, the patient may not be Blood gas measurements are used to breathing deeply or often enough. If it’s too low, they might be breathing too fast. determine the partial pressure of = oxygen (PO2) and carbon dioxide (PCO2) in the blood. know acidicosis vs alkalosis Arterial blood is preferred for measuring blood gasses because venous levels of oxygen and carbon dioxide reflect the Monitoring Blood pH (Acidity): The pH tells us if the blood is too acidic or too basic. A normal pH is important for the body to work properly. If it’s out of metabolic demands of the tissues rather balance, there could be a problem with breathing or metabolism. than the gas exchange function of the Checking if the Body is Trying to Fix the Issue (Compensation): Sometimes, the body tries to adjust to fix pH problems. For example, if the blood is too acidic, the lungs. usually doctor does it… but if nurse does it body might change other levels to balance it out. in small town its VBG Using the Information to Help the Patient: Based on ABG results, nurses decide if the patient needs more oxygen, different medications, or other treatments to help them breathe better and keep their blood balanced.  INNERVATION The lungs ae innervate by the sympathetic & parasympathetic divisions of the autonomic NS fight or flight Stimulation of the parasympathetic NS (cholinergic receptors) leads to bronchial constriction and increased glandular secretions. rest and digestr Stimulations of the sympathetic NS (particularly B2 adrenergic receptors) cause airway relaxation, blood vessel constriction, and inhibition of glandular secretion. b2 are the lungs cuz u have 2 lungs This bronchial constriction reduces airflow a bit, which is fine when the body is at rest and doesn’t need as much oxygen. In contrast, when you’re active, the sympathetic nervous system (the "fight or flight" system) kicks in, relaxing the bronchial muscles and allowing the airways to dilate (open up) to take in more oxygen.  LUNG DISEASES Restrictive lung disease: the lung tissue or chest muscles can’t expand enough. This creates problems with air flow, mostly because you have less lung volume. E.g. Pulmonary Fibrosis. Obstructive lung disease: air has trouble flowing out of the lungs because of airway resistance. This causes slower flow of air. E.g. Asthma, chronic bronchitis, emphysema.  ASTHMA (obstructive lung disease) Asthma is a chronic inflammatory disorder of the airways that causes episodes of airway obstruction, bronchial hyperresponsiveness, airway inflammation, and sometimes airway remodeling. Linked to an exaggerated hyperresponsiveness where the airways become inflamed after someone with asthma breathes in irritants (like dust or smoke), causing their immune system to react strongly leading to swelling and excess mucus production in the airways. When mast cells are activated, cytokines (TNF-α, interleukins), histamine, prostaglandin D2, and leukotrienes cause massive bronchoconstriction and inflammation of pulmonary vasculature endothelium. Over time, this inflammation can damage the epithelial cells (protective layer lining the airways). The damage makes it harder for the airways to function properly, causing symptoms like wheezing, coughing, and difficulty breathing. With proper management and treatment, like avoiding triggers and using medications, the inflammation can be controlled, allowing the epithelial cells to heal and function better. However, if asthma is poorly managed over time, it can lead to more lasting changes in the you are trying to get the air airways, sometimes referred to as airway remodeling. This can make the airways more sensitive out but it is too small of a and increase the risk of future asthma symptoms. bhroncile hole the main thing is to avoid the triggers asthma at a certian time it is reversable and healable… that is a major difference between Ashtma and COPD ASTHMA ) ) ) ) ) ) ) ) ) ASTHMA ) ) ) ) ) ) ) ) ) Chronic inflammatory airway disorder (not autoimmune). Affects up to 10% Canadians Risk factor: family history. Triggers: noxious stimuli (allergens, environmental particles, infection, stress, etc.) Inflammation + pro-inflammatory mediators activating further inflammation! mast cell degranulation WBC signaling: especially T- lymphocytes & interleukins; Eosinophils, Basophils, Neutrophils, Macrophages TH2-helper cells => signal B-cells to synthesize IgE => crosslinks receptors – mast cell degranulation chronic inflammatory mucosal changes => hypersensitivity + high goblet cell activity (mucous) Outcome: bronchial inflammation, bronchoconstriction, mucous production ASTHMA ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ASTHMA CLINICAL PRESENTATION ) ) ) ) ) ) ) ) ) Epithelial injury in the bronchi => chronic hypersensitivity ‘reactivity’ of the bronchial airways. risk of attacks: exposure triggers acute ‘attacks’ Asthma Attack S&S: Wheezing, shortness of breath, reduced air entry into lung lobes, chest tightness, tachycardia, anxiety, panic, fatigue. Limited inspiration + longer expiration phase => air trapping in alveoli heart and lungs are connected remeber hyper-inflated lungs with limited gas exchange ventilation-perfusion’ mismatch ventilaton Low O2 & high CO2 Hypoxemia, hypercarbia & high pulmonary pressures the more injury to the epithelial layer of the bronchi ——>more inflammation ——>more swelling ) ) ) ) ) ) ) ) ) ASTHMA CLINICAL PRESENTATION ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ASTHMA TREATMENTS ) ) ) ) ) ) ) ) ) Drugs used to stabilize asthma are called ‘maintenance’ drugs, while those used during acute asthma attack are called ‘rescue’ drugs. Management of asthma focuses on: stabilizing the bronchial inflammation & minimizing the number of attacks. avoidance of triggers (if possible). acquire control of the inflammation with a daily treatment protocol & compliance. proper use of inhaler; proper dose; avoidance of respiratory infections. ) ) ) ) ) ) ) ) ) MAINTENANCE TX OF ASTHMA ) ) ) ) ) ) ) ) ) Inhaled anti-inflammatory drugs exert local effect in bronchioles, causing low systemic=> Low side effects. when u inhale; it doesnt go systemic so u dont get like immunosuppression etc GLUCOCORTICOIDS MAST CELL STABILIZERS 1st line for maintenance/prophylaxis Inhibit histamine release from mast treatment against asthma attacks cells. Drugs: Budesonide (Pulmicort), Fluticasone (Flovent), Beclomethasone (Qvar) Drug: Cromolyn Inhaler Slow onset of therapeutic level. Frequent dosing: 3-4 times/day Administration: Not common as 1st choice inhalers (metered dose inhalers, dry Synergy with glucocorticoids powder inhalers) nebulizers use nebulizer in emergency for sure and children ) ) ) ) ) ) ) ) ) MAINTENANCE TX OF ASTHMA ) ) ) ) ) ) ) ) ) wors sorta Maintenance drugs are administered daily, even if not attacks, to control triggers. like histamine… so it slows LEUKOTRIENE BIOLOGICS: MONOCLONAL inflammation MODIFERS ANTIBODIES Block leukotriene receptors Drug: Omalizumab (Xolair) Modify inflammatory response pre- e Binds free IgE => decreases antigen exposure (prophylaxis) binding => no degranulation Drug: Montelukast (Singulair) Decreases expression of mast cell- Administered PO bound IgE => no degranulation. Systemic effects Slow onset of action Long-term treatment plan Synergy treatment mab ending = biologics ) ) ) ) ) ) ) ) ) MAINTENANCE TX OF ASTHMA ) ) ) ) ) ) ) ) ) e ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) 03 YOU UP? What does SNS stimulation cause in asthma treatment? How will you know the patient is improving?  ACUTE TREATMENT OF ASTHMA (RESCUE) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) -Treat bronchoconstriction via inhaler or Nebulizer BETA-2 ADRENERGIC ANTICHOLINERGICS AGONIST Antagonize Parasympathetic NS, Stimulates sympathetic NS’ B2 causing bronchodilation. receptors directly. Less potent & has slower onset of Potent & Fast-acting action. Synergic with Beta-2-Agonists Drugs: Drugs: Atrovent (Ipratopium) Salbutamol/Albuterol (Ventolin) Formoterol inhibit parasympthatic can also come in liquid form that we can put in nebulizer ) ) ) ) ) ) ) ) ) STATUS ASTHMATICUS ) ) ) ) ) ) ) ) ) Sever asthma attack (ER admission). Signs and Symptoms: severe SOB,- accessory muscle use, bluish tint to lips, chest tightness, anxiety/panic AHS protocol - https://www.albertahealthservices.ca/frm-21051.pdf acute asthma admission Treatment: Oxygen therapy Beta- Adrenergic Agonist (Ventolin) via NEBULIZER Magnesium Sulfate helps with bronchodialation Glucocorticoids IV (Dexamethasone) Anticholinergics via NEBULIZER Sympathomimetics: Epinephrine IV Potent with short half-life. stimulating the entire sympathetic nervous system The goal is bronchodilation Side effect: SNS stimulation ) ) ) ) ) ) ) ) ) STATUS ASTHMATICUS ) ) ) ) ) ) ) ) ) Magnesium Sulfate Electrolyte, Calcium Channel Blocker. Can be titrated to effect to alleviate severe bronchoconstriction. Mechanism: inhibition of Ca channels in smooth muscle => reduced cellular excitability => bronchodilation stabilization of mast cells & T-cells => decreased pro-inflammatory mediators. enhanced release of NO => vasodilation, pulmonary vasodilation = improved gas exchange NO is potent vasodilator Side effect: hypotension, skin flushing, confusion ) ) ) ) ) ) ) ) ) ASTHMA VS ANAPHYLAXIS ) ) ) ) ) ) ) ) ) Definition: Asthma: A chronic condition characterized by inflammation and narrowing of the airways Anaphylaxis: A severe, life-threatening allergic reaction that can occur suddenly. ashma also has mucus production whereas anaphylaxis does not; ashma is Triggers:eposidic…whereas anaphylaxis is more sudden. anaphylaxis usually due to food Asthma: Allergens (like pollen, dust mites), irritants (smoke, pollution), exercise, and respiratory infections. Anaphylaxis: Commonly caused by foods (like peanuts or shellfish), insect stings, medications, or latex. Symptoms: Asthma: Wheezing, coughing, shortness of breath, chest tightness. Symptoms can be episodic and vary in severity. Anaphylaxis: Rapid onset of symptoms such as difficulty breathing, swelling of the throat, hives, low blood pressure, and gastrointestinal symptoms. similar: both use epinephrine; steroids; goal is bhroncodilation Difference in treatment? administration route; anaphalyxis treat right away ) ) ) ) ) ) ) ) ) ASTHMA VS ANAPHYLAXIS ) ) ) ) ) ) ) ) ) epininephrine then alberutrol first then think about asthma vs anaphylaxis ) ) ) ) ) ) ) ) ) CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) ) ) ) ) ) ) ) ) ) COPD = Chronic Bronchitis + Emphysema. Risk factors Smoking Long-term exposure environmental pollutants and chemicals. >40 years old Chronic Bronchitis: irreversible damage to bronchial tubes leading to persistent inflammation and irritation of the airway tubes that causes narrowing/obstruction. kinda like asthma but Causes SOB, Cough and excess mucus production. its not like the immune system is Symptoms: Long-term cough with sputum. actually responding Chronic inflammation can lead to structural changes over time (progressive disease). Emphysema: permanent damage and loss of elasticity in alveoli, leading to poor recoil and air trapping (poor exhalation = increased CO2). Symptoms: pursed-lip breathing, tripoding, barrel chest. ) ) ) ) ) ) ) ) ) MANAGEMENT OF COPD ) ) ) ) ) ) ) ) ) Smoking cessation is the single most effective step in managing COPD. Oxygen therapy for acutely low oxygen level (CAUTION CO2 retention!!!). Vaccinations: Influenza and Pneumonia vaccinations to prevent infections that might exacerbate COPD. Medications Bronchodilators Beta-Agonists: Albuterol (short-acting), Formoterol (Long-acting) Anticholinergics: Ipratropium/Atrovent (Short-acting), Tiotropium/Spiriva (Long-acting) Inhaled Corticosteroids: Budesonide, Fluticasone Combination Inhalers: Advair = Salmeterol (LABA) + Fluticasone (Advair) Symbicort = Formoterol (LABA) + Budesonide (Symbicort) Mucolytics: Acetylcysteine (Mucomyst) in nebulizer to loosen sputum ) ) ) ) ) ) ) ) ) NURSING CONSIDERATIONS R/T COPD ) ) ) ) ) ) ) ) ) Assessment Respiratory Status: Monitor respiratory rate, effort, and lung sounds. Assess for signs of hypoxia (e.g., cyanosis, confusion) and hypercapnia (e.g., drowsiness). Oxygen Saturation: Regularly check oxygen levels using pulse oximetry, ensuring they are within the target range set by the healthcare provider (typically 88-92%). Medication Management Administer meds and education patient on on the proper use of inhalers, nebulizers, and any combination medications to ensure effective delivery of medications. Oxygen administration as needed. Also educate patient about fire hazards if discharged with O2. Patient Education Educate patients about COPD, its progression, and self-management strategies, including recognizing early signs of exacerbations such as increased breathlessness, changes in sputum color or volume. Provide information on the risks of smoking and support for cessation, including referral to smoking cessation programs. ) ) ) ) ) ) ) ) ) NURSING CONSIDERATIONS R/T COPD ) ) ) ) ) ) ) ) ) Breathing Techniques Pursed-Lip Breathing: Teach this technique to help reduce dyspnea and improve ventilation. Energy Conservation: Educate patients on techniques to conserve energy during daily activities. Nutrition Monitor nutritional status and provide education on a balanced diet. Consider small, frequent meals that are high in protein and calories to maintain strength. Hydration: Encourage adequate fluid intake to help thin mucus secretions. Psychosocial Support Assess for signs of anxiety or depression, which are common in COPD patients. Provide support or referrals to mental health services and support groups as needed. ) ) ) ) ) ) ) ) ) COPD RESOURCES ) ) ) ) ) ) ) ) ) https://www.lungsask.ca/document/copd-inhaled-medications.pdf https://myhealth.alberta.ca/health/pages/conditions.aspx?Hwid=zx3179