Respiratory System - Paramedic Science PDF

Paramedic Science Health & Human Development 2 The Respiratory System  Function The function of the respiratory system include the intake of oxygen and the removal of CO2. Cells need oxygen to break down nutrients to release energy and produce adenosine triphosp...

Paramedic Science Health & Human Development 2 The Respiratory System  Function The function of the respiratory system include the intake of oxygen and the removal of CO2. Cells need oxygen to break down nutrients to release energy and produce adenosine triphosphate. CO2 results from this process and must be excreted. The respiratory system includes tubes that filter incoming air while transporting it into and out of the lungs. Gases are exchanged in microscopic air sacs. Respiratory organs entrap incoming air particles, control temperature and water (H20) content in the air, produce vocal sounds, regulate blood pH, and are essential for the sense of smell.  Function Respiration is the process of gas exchange between the atmosphere and cells. There are four Major events that are involved in respiration. The first two are handled by the respiratory system the last two are handled by the circulatory system.  Event 1 Movement of air in and out of the lungs is called pulmonary ventilation or breathing, involving inward movement or inspiration and outward movement or expiration, in which gases are changed and refreshed continuously.  Event 2 Gas exchange between air in the lungs and the blood or external respiration; Oxygen diffuses from the lungs to the blood, whereas CO2 diffuses from the blood to the lungs.  Diffusion of oxygen, CO2, and nitrogen between gas and liquid forms follow the laws of how gases exist. Different partial pressures and solubilities influence the direction and the diffusion rate across the respiratory membrane separating air inside the alveoli from blood inside the alveolar capillaries.  Daltons Law Dalton's law (also called Dalton's law of partial pressures) states that in a mixture of non-reacting gases, the total pressure exerted is equal to the sum of the partial pressures of the individual gases Event 3 Gas transport in blood between the lungs and the body cells, accomplished by cardiovascular system. Using blood as the transporting fluid; oxygen is transported from the lungs to the body’s tissue cells, whereas CO2 is transported from the tissue cells to the lungs.  Event 4 Gas exchange between the blood and the cells or internal respiration. Oxygen diffuses from the blood to the body's tissue cells, whereas CO2 diffuses from the tissue cell’s to the blood.  Partial Pressures Partial pressure (Px) is the pressure of a single type of gas in a mixture of gases. For example, in the atmosphere, oxygen exerts a partial pressure, and nitrogen exerts another partial pressure, independent of the partial pressure of oxygen. Total pressure is the sum of all the partial pressures of a gaseous mixture. Dalton’s law describes the behaviour of nonreactive gases in a gaseous mixture and states that a specific gas type in a mixture exerts its own pressure; thus, the total pressure exerted by a mixture of gases is the sum of the partial pressures of the gases in the mixture.  Partial Pressures of Air COMPONENT PERCENTAGE IN PARTIAL PERCENTAGE IN PARTIAL ALVEOLI PRESSURE IN ATMOSPHERE (AT PRESSURE IN ALVEOLI SEA LEVEL) ATMOSPHERE (AT SEA LEVEL) Carbon Dioxide 5.2 40 mm Hg 0.04 0.3 mm Hg Nitrogen 74.9 569 mm Hg 78.6 597 mm Hg Oxygen 13.7 104 mm Hg 20.9 159 mm Hg Water 6.2 47 mm Hg 0.46 3.7 mm Hg  Mechanics of Respiration When the lungs inhale, the diaphragm contracts and pulls downward. At the same time, the muscles between the ribs contract and pull upward. This increases the size of the thoracic cavity and decreases the pressure inside. As a result, air rushes in and fills the lungs.  Boyles Law The absolute pressure exerted by a given mass of an ideal gas is inversely proportional to the volume it occupies if the temperature and amount of gas remain unchanged within a closed system  Tidal Volume Respiratory capacities as well as respiratory volumes are useful for diagnosing problems with pulmonary ventilation. On average, adult females have smaller bodies and lung volumes than adult males, which is why there are gender-related differences. (Jahangir Moini, 2020)  Average Respiratory Volumes in Adults RESPIRATORY AVERAGE ADULT AVERAGE ADULT COMMENTS VOLUMES MALES FEMALES Under resting Tidal Volume 500 mL 500 mL conditions, the air inhaled or exhaled with each breath Air that can be Inspiratory Reserve 3,100 mL 1,900 mL forcibly inhaled after Volume normal TV inspiration Air that can be Expiratory Reserve 1,200 mL 700 mL forcibly exhaled after Volume normal TV expiration Air remaining in the Residual Volume 1,200 mL 1,100 mL lungs after forced exhalation  Dead Space A certain amount of inspired air does not contribute to alveolar gas exchanged but fills the conducting respiratory passageways. Anatomic dead space is made up of the volume of these conducting conduits. The dead space is approximately 150 mL. for example, only 350 mL of air are used in alveolar ventilation out of a tidal volume of 500 mL.  Control of Breathing The respiratory centre resides in the medulla oblongata and pons. Respiratory control has both involuntary and voluntary control components. The involuntary centres of the brain regulate the respiratory muscles. They control respiratory minute volume by adjusting the depth and the frequency of pulmonary ventilation. This occurs as a result of sensory information the arrives from the lungs and various portions of the respiratory tract and a variety of other sites, via both chemo and baro receptors. The voluntary control of respiration reflects activity in the cerebral cortex and is under conscious control. Control of Breathing By definition central respiratory chemoreceptors (CRCs) are cells that are sensitive to changes in brain PCO2 or pH and contribute to the stimulation of breathing elicited by hypercapnia or metabolic acidosis Hypoxic Drive To give O2 or not to give O2? That is the question! The hypoxic drive is a form of respiratory drive in which the body uses oxygen chemoreceptors instead of carbon dioxide receptors to regulate the respiratory cycle.  Ventilation/Perfusion Mismatch A V/Q mismatch happens when part of your lung receives oxygen without blood flow or blood flow without oxygen. This happens if you have an obstructed airway, such as when you’re choking, or if you have an obstructed blood vessel, such as a blood clot in your lung. It can also happen when a medical condition causes you to bring in air but not extract oxygen or bring in blood but not pick up oxygen. A V/Q mismatch can cause hypoxemia, which is low oxygen levels in your blood. Not having enough blood oxygen can lead to respiratory failure.  Pathophysiology Asthma Is a chronic pulmonary disease that produces intermittent, reversible airway obstruction. It is characterised by acute airway inflammation, bronchoconstriction, bronchospasm, bronchiole oedema and mucus production. Asthma is the most common chronic illness in children.  Pathophysiology Asthma  Pathophysiology Asthma Signs and Symptoms Airway – Should be clear but expect cyanosis, potential for coughing. Breathing – Tachypnoea, Dyspnoea, Reduced SPO2, Accessory muscle use, Shallow resps, Expiratory wheeze, Hyper resonant. Circulation – Delayed cap refill, Bounding pulse, Tachycardia, Hypertension, Sinus Tachycardia on ECG Disability – Reduced GCS, BM potential to be reduced, Temp potential to be high, Pupils dilated.  Pathophysiology Asthma Treatment Follow JRCALC Asthma: Assessment and Management Algorithm.  Pathophysiology Chronic Obstructive Pulmonary Disease Emphysema Chronic Bronchitis Industrial Lung Diseases  Pathophysiology Chronic Bronchitis Is an obstructive respiratory disorder characterised by inflammation of the bronchi, a productive cough, and excessive mucus production. This disorder differs from acute bronchitis in that the chronic type is not necessarily caused by infection and symptoms persist longer.  Pathophysiology Chronic Bronchitis Smoking is the greatest contributing factor for chronic bronchitis. The inflammatory response results in mucous gland hyperplasia, oedema, excessive mucous production, bronchoconstriction and a cough as a defence against inhaled irritants. Airway resistance affects both inspiratory and expiratory air flow.  Pathophysiology Chronic Bronchitis Signs & Symptoms Airway – Cyanosis, Productive cough, perhaps audible rhonchi Breathing – Dyspnoea, Tachypnoea, Inspiratory & Expiratory Wheeze, Reduced SPO2 Circulation – Delayed cap refill, Tachycardia, Hypertension, Sinus Tachycardia on ECG. Disability – Reduced GCS, Pupils dilated, BM Normal, Possible pyrexia  Pathophysiology Chronic Bronchitis Treatment Follow JRCALC Chronic Obstructive Pulmonary Disease: Assessment and management of COPD.  Pathophysiology Emphysema Emphysema is an obstructive respiratory disorder that results in the destruction of the alveolar walls, leading to large, permanently inflated alveoli.  Pathophysiology Emphysema Signs & Symptoms Airway – Cyanosis, Productive cough, perhaps audible rhonchi Breathing – Dyspnoea, Tachypnoea, Inspiratory & Expiratory Wheeze, Reduced SPO2, diminished breath sounds. Barrel chested, hypercapnia Circulation – Delayed cap refill, Tachycardia, Hypertension, Sinus Tachycardia on ECG. Disability – Reduced GCS, Pupils dilated, BM Normal, Possible Pyrexia  Pathophysiology Emphysema Treatment Follow JRCALC Chronic Obstructive Pulmonary Disease: Assessment and management of COPD.  Pathophysiology Industrial/Occupational Lung Diseases Asbestosis Silicosis Pneumoconiosis Infectious Diseases  Pathophysiology Industrial/Occupational Lung Diseases Asbestosis Asbestosis is a serious lung condition caused by long-term exposure to asbestos. Asbestos is a fibre-like material that was once used in buildings for insulation, flooring and roofing. Its use has been fully banned in the UK since 1999. While asbestos can be dangerous, it's not harmful if left alone  Pathophysiology Industrial/Occupational Lung Diseases Silicosis Silicosis is a long-term lung disease caused by inhaling large amounts of crystalline silica dust, usually over many years. Silica is a substance naturally found in certain types of stone, rock, sand and clay. Working with these materials can create a very fine dust that can be easily inhaled  Pathophysiology Industrial/Occupational Lung Diseases Pneumoconiosis Pneumoconiosis is one of a group of interstitial lung disease caused by breathing in certain kinds of dust particles that damage your lungs. Because you are likely to encounter these dusts only in the workplace, pneumoconiosis is called an occupational lung disease. Pneumoconiosis usually take years to develop  Pathophysiology Industrial/Occupational Lung Diseases Infectious Diseases TB is caused by bacteria (Mycobacterium tuberculosis) and it most often affects the lungs. TB is spread through the air when people with lung TB cough, sneeze or spit. A person needs to inhale only a few germs to become infected.  Pathophysiology Industrial / Occupational Lung Disease Treatment Follow JRCALC Chronic Obstructive Pulmonary Disease: Assessment and management of COPD.  Pathophysiology Cystic Fibrosis Cystic fibrosis (CF) is one of the UK's most common life- threatening inherited diseases. Cystic fibrosis is caused by a defective gene. As a result, the internal organs, especially the lungs and digestive system, become clogged with thick sticky mucus resulting in chronic infections and inflammation in the lungs and difficulty digesting food.  Pathophysiology Cystic Fibrosis Treatment Follow JRCALC Chronic Obstructive Pulmonary Disease: Assessment and management of COPD.  Pathophysiology Pulmonary Embolism Pulmonary embolism is a blockage in one of the pulmonary arteries in your lungs. In most cases, pulmonary embolism is caused by blood clots that travel to the lungs from deep veins in the legs or, rarely, from veins in other parts of the body (deep vein thrombosis).  Pathophysiology Pulmonary Embolism Signs & Symptoms Airway – Cough, cyanosis, pink frothy sputum. Breathing – Tachypnoea, Dyspnoea, Reduced SPO2, Crackles or wheeze. Circulation - Tachycardia, Irregular and weak pulse, Hypertension, clammy skin. Disability – GCS Normal, PEARRLA, BM Normal, Temp may be pyrexia. Chest Pain.  Pathophysiology Pulmonary Embolism Treatment Follow JRCALC Pulmonary Embolism: Assessment and Management Algorithm.  Pathophysiology Pneumonia Pneumonia is swelling (inflammation) of the tissue in one or both lungs. It's usually caused by a bacterial infection or a virus.  Pathophysiology Pneumonia Signs & Symptoms Airway – Cough. Breathing – Tachypnoea, Dyspnoea, Reduced SPO2, Crackles or wheeze. Circulation - Tachycardia, Irregular and weak pulse, Hypertension, clammy skin and warm. Disability – GCS may be reduced, PEARRLA, BM Normal, Pyrexia. Chest tightness.  Pathophysiology Pneumonia Treatment Follow JRCALC Guidelines and administer O2 as necessary. Pathophysiology Pleurisy Pleurisy is a condition in which the pleura — two large, thin layers of tissue that separate your lungs from your chest wall — becomes inflamed. Also called pleuritis, pleurisy causes sharp chest pain (pleuritic pain) that worsens during breathing.  Pathophysiology Pleurisy Signs & Symptoms Airway – Clear. Breathing – Shallow, Tachypnoea, Dyspnoea, Reduced SPO2, Pleuritic Rub. Circulation - Tachycardia, Hypertension, Warm, dry skin, Normal Cap refill. Disability – GCS Normal, PEARRLA, BM Normal, Pyrexia. Chest Pain, worse on taking big breaths.  Pathophysiology Pleurisy Treatment Follow JRCALC Guidelines and administer O2 as necessary.  Pathophysiology Plural Effusion Pleural effusion is the build-up of excess fluid between the layers of the pleura outside the lungs.  Pathophysiology Pleural Effusion Signs & Symptoms Airway – Clear. Breathing – Shallow, Tachypnoea, Dyspnoea, Reduced SPO2, diminished breath sounds, hyporesonant. Circulation - Tachycardia, Hypertension, Warm, dry skin, Normal Cap refill. Disability – GCS Normal, PEARRLA, BM Normal, Pyrexia. Chest Pain, worse on taking big breaths.  Pathophysiology Pleural Effusion Treatment Follow JRCALC Guidelines and administer O2 as necessary.  Contact Information Should you have any questions you should contact the module lead in the first instance. Followed my your syndicate lead if appropriate. Module Lead: Will Hendry [email protected] Programme: Paramedic Science [email protected]