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PRECLINEAZY Case 3 – Respiratory Diya Lakhwani Case 3 Todays Session will cover ABG’ s Respiratory failure Obstructive vs restrictive PharmacologyARTERIAL BLOOD GASES (ABGs) Question 1 A 50-year-old patient with known COPD comes into A&E. He A Metabolic acidosis with respiratory compensation presents with extreme shortness of breath. You are the junior doctor on the wards and are asked to do an ABG. The results Respiratory acidosis with metabolic are as shown below: B compensation pH: 7.25 (7.35 - 7.45) C Normal ABG pCO2: 9.1 kPa (4.5 - 6.0 kPa) pO2: 6.8 kPa (10 - 14 kPa) D Metabolic alkalosis HCO3: 24 mmol/L (22-26 mmol/L) BE: +1 (-2 to +2) E Respiratory acidosis What is the most likely diagnosis? ABG’S HCO - - levels of 3 bicarbonate in the pH - measure of blood blood – it is exhaled acidity/alkalinity as CO 2 NORMAL VALUES pH → 7.35 – 7.45 PaO →211-13 kPa PaCO →24.6 – 6 kPa PaO – Partial HCO 3- → 22-28 mmol/L 2 BE → -2 to +2 pressure of oxygen PaCO –2Partial in arterial blood pressure of carbon dioxide in arterial blood Base excess - Excess or deficit of base in arterial blood ABG INTERPRETATION ASSESS LOOK AT CONFIRM PATIENT OXYGENATION – IS RESPIRATORY DETAILS – NAME & THE PATIENT IN ASSESS ACIDITY – IS COMPONENT - CHECK DOB RESPIRATORY THE pH LOW OR HIGH? CO 2RAISED = FAILURE? (<8 kPa) ACIDOSIS) NOTE: LOOK AT METABOLIC CHECK FOR COMPONENT - CHECK METABOLIC/RESPIRATORY Type 1 Resp Failure = Low PaO2 HCO (RAISED = COMPENSATION & CHECK Type 2 Resp Failure = Low PaO2 + high 3 ALKALOSIS) BASE EXCESS TO CONFIRM PaCO2 CHANGE IN CO2 = RESPIRATORY CHANGE IN HCO3 = METABOLIC ACIDOSIS/ALKALOSIS pH – alkalosis or acidosis? ACIDOSIS/ALKALOSIS A base excess more than +2 indicates A base excess less than -2 indicates a a metabolic alkalosis. pH < 7.35 pH > 7.35 metabolic acidosis. Acidosis Alkalosis Is CO2 low? Is CO2 high? Is HCO3 low? Is HCO3 high? Respiratory acidosis Metabolic acidosis Respiratory alkalosis Metabolic alkalosis COMPENSATION Metabolic alkalosis Respiratory acidosis Metabolic alkalosis Respiratory alkalosis Question 1 A 50-year-old patient with known COPD comes into A&E. He A Metabolic acidosis with respiratory compensation presents with extreme shortness of breath. You are the junior doctor on the wards and are asked to do an ABG. The results Respiratory acidosis with metabolic are as shown below: B compensation pH: 7.25 (7.35 - 7.45) C Normal ABG pCO2: 9.1 kPa (4.5 - 6.0 kPa) pO2: 6.8 kPa (10 - 14 kPa) D Metabolic alkalosis HCO3: 24 mmol/L (22-26 mmol/L) BE: +1 (-2 to +2) E Respiratory acidosis What is the most likely diagnosis? ABG EXAMPLES SCENARIO 1 SCENARIO 2 You are the junior doctor on call and you see a 58-year-old You’re asked to review a 63-year-old male who has recently female patient with a 48 hour history of vomiting, nausea and been admitted to the ward. The nurse tells you that he is short abdominal distention. As part of the patient’s assessment, an of breath despite having 8 liters of oxygen delivered through ABG is done. The results are shown below: an oxygen mask. An ABG is performed, and the results are shown below. pH = 7.49 (7.35-7.45) pH = 7.28 (7.35-7.45) PaO2 = 12.4 kPa (11-13 kPa) PaO2 = 9.6 kPa (11-13 kPa) PaCO2 = 5.3 kPa (4.7-6 kPa) PaCO2 = 8.8 kPa (4.7-6 kPa) HCO3 = 30 (22-28 mmol/L) HCO3 = 31(22-28 mmol/L) BE = +4 (-2 to +2) BE = +3 (-2 to +2) What is the likely diagnosis? What is the likely diagnosis? METABOLIC ALKALOSIS RESPIRATORY ACIDOSIS WITH METABOLIC COMPENSATIONRESPIRATOR Y AILURE – TYPE I & II TYPE 1 RESP F AILURE • Hypoxaemia (low PaO2) • PaO2 < 8kPa • Hypoxaemia • Normal/low PaCO2 • PaO2 < 8kPa • Oxygenation failure VS • Hypercapnia (High PaCO2) • PaCO2 > 6kPa • Ventilation failure TYPE 2 RESP F AILURE TYPE 1 RESP . FAILURE CAUSES TYPE 2 RESP . FAILURE CAUSES 1. V/Q mismatch 1. Depression of respiratory center of brain - Pulmonary embolus (ventilation but poor perfusion) - Stroke, drug overdose (eg. Heroin) → reduced breathing - Pneumonia & asthma (perfusion but poor ventilation) rate → hypoventilation (↑ CO &2↓O ) 2 2. Diffusion deficit - Pulmonary fibrosis → thickened interstitium → inadequate 2. Respiratory muscle weakness gas exhange - Neurological conditions → reduced depth of breathing → hypoventilation - Neurological conditions = MND, Guillain-Barre, Muscular 3. Right-left shunt dystrophy, spinal cord lesions - Mixing of deoxygenated and oxygenated blood - Blood bypasses lungs so can’t get oxygenated - Eg. AVM & patent foramen ovale 3. Chest wall deformities - Caused by obesity, kyphoscoliosis & thoracoplasties 4. Increased oxygen consumption 4. Lung disease - Long operations, extreme exercise, sepsis - Emphysema and asthma 5. Low alveolar oxygen content - High altitudes 6. Hypoventilation - Breathing less/ under-breathing - Causes = drugs (eg. Opiates) and obesity - Hypoventilation ends up causing low 0 2nd high CO = 2 type 2 resp. failure Question 2 A 10-year-old girl and her mother present to the GP . The A Bronchiectasis mother is worried as her daughter seems to have a dry, irritating cough since a few weeks and is also presenting with B COPD shortness of breath. Spirometry reveals an FEV1:FVC ratio of 0.45, which increases after a salbutamol inhaler. C Asthma Given the above information, what is the most likely diagnosis? D Idiopathic pulmonary fibrosis E Cystic fibrosisLUNG DISEASES … OBSTRUCTIVE • Difficulty during expiration / hard to breathe out and get air out of the lungs • Difficulty during inspiration/hard • FEV1:FVC < 0.7 to breathe in and get air into the • FEV1 ↓ VS lungs • FVC normal/↓ • FEV1 ↓ • FVC ↓ • FEV1:FVC >/= 0.7 RESTRICTIVE Question 3 A 53-year-old male presents with a dry cough that is A Bronchiectasis persistent and doesn’t seem to be improving. He hasn’t recently lost any weight and has a 20-pack year history of smoking. A respiratory examination is performed. Findings B COPD include finger clubbing and fine end inspiratory crackles are heard on auscultation. C Asthma Given the above information, what is the most likely D Idiopathic pulmonary fibrosis diagnosis? E Lung cancerRESTRICTIVE LUNG DISEASES RESTRICTIVE LUNG DISEASE PULMONAR Y EXTRA-PULMONAR Y • PULMONARY FIBROSIS • OBESITY • PULMONARY OEDEMA • KYPHOSCOLIOSIS • TUMOUR • PLEURAL EFFUSION • PNEUMONIA • NEUROMUSCULAR DISEASE (eg. Guillain-Barre, Myasthenia Gravis and motor neurone diseasePULMONARY RESTRICTIVE DISEASE IDIOP A THIC PULMONAR Y FIBROSIS SYMPTOMS PATHOPHYSIOLOGY - Dyspnoea - Thickening of the interstitium - Dry cough - Infiltration of plasma cells and lymphocytes - Fatigue - Infiltration of fibroblasts - They lay down collagen - Weight loss - Lungs become less elastic and stiff - Rapid, shallow - Harder to take air in breathing - Fever CLINICAL SIGNS CAUSES - Finger clubbing - Most commonly idiopathic = - Cyanosis no known cause - Fine, end - Asbestos exposure - Silicon exposure inspiratory - Interstitial lung disease (ILD) crackles - Drug induced – amiodarone -IPF IMAGING HONEYCOMBING PNEUMONIA CAUSES PATHOPHYSIOLOGY - Community aquired = Strep. - Inflammation of the alveoli - WBCs and bacteria accumulate in Pneumoniae (severity the air sacs determined by CURB-65 score) - Alveoli gets filled with pus and - Hospital acquired = Gram –ve bacilli e.g.. aeruginosa, E.coli, fluid Klebsiella pneumoniae - Oxygen intake is limited, making inspiration difficult SYMPTOMS & SIGNS - Cold or flu - Chest pain on breathing/coughing - Fatigue - SOB - N/V - DiarrhoeaEXTRA PULMONARY RESTRICTIVE DISEASE OBESITY - There is increased adipose tissue around neck and thoracic cavity - Harder to breathe effectively Can cause: NORMAL SLEEP APNOEA - Obstructive sleep apnoea syndrome (OSAS) - Obesity hypoventilation syndrome (OHS) Question 4 A 60-year-old female presents with a persistent, productive A Bronchiectasis cough. She complains of fatigue and breathlessness. She has a 30-pack year history of smoking. On examination, you notice pursed-lip breathing and the use of accessory muscles B COPD to assist her breathing. C Asthma Given the above information, what is the most likely diagnosis? D Idiopathic pulmonary fibrosis E Lung cancerOBSTRUCTIVE LUNG DISEASES OBSTRUCTIVE LUNG DISEASE Emphysema Chronic Bronchitis A SET OF CONDITIONS IN WHICH AIRWYS ARE OBSTRUCTED, IMPAIRING VENTILATION AND MAKING IT HARD TO BREATHE OUT ASTHMA COPD Cystic Fibrosis Bronchiectasis ASTHMA (reversible) PATHOPHYSIOLOGY - Airway inflammation; bronchi become narrowed SYMPTOMS - Inhaled allergen activates dendritic cells - Dendritic cells activates Th-2 cells - SOB - Th-2 promotes IgE antibody production from B cells - Wheeze - Chest tightness - IgE binds to Mast cells which release histamine - Dry, irritating (bronchoconstriction), prostaglandins, leukotrienes, and inflammatory cytokines (bronchial inflammation) cough Normal Airway Asthma Airway - All together = bronchial SM constriction - Healthy Airway Asthma Airway Asthma Attack HISTOLOGY Increased: - Goblet cells = increased mucus production - Eosinophils in mucus - Mast cells = increased histamine - Neutrophils = highly inflammatory Normal Airway Excess airway Constricted Airway smooth muscle smooth muscle asthma attack Contracted airway smooth muscle COPD (irreversible) EMPHYSEMA CHRONIC BRONCHITIS - Destruction to alveolar wall→ loss of - Trigger such as cigarette smoke causes elasticity - Abnormal & permanent alveolar large and small airways - (bronchi dilation and bronchioles) to get blocked and - Loss of elastic recoil in acinus inflamed and hyper-secrete mucus - Muco-ciliary dysfunction → inability to - Air is trapped → difficult to breathe clear mucous out - Narrowed airways →Ultimately, leads to obstruction to air flow COPD (irreversible) SIGNS & SYMPTOMS CAUSES - Progressive breathlessness - Smoking - Fatigue, weight loss, appetite loss, - Genetic factors →Alpha-1 Antitrypsin oedema - Industrial causes e.g. Cadmium (used in smelting), coal, cotton, cement, - Cachexia = loss of muscle mass grain - Quick breathing, using accessory muscles - Nutritional, maternal smoking - Pursed lip breathing - Biomass fuel emission - Wheezing - Barrel–chest (hyperinflated lungs) due to air trapped in the alveoli BRONCHIECTASIS PLEURAL EFFUSION vs (obstructive) PULMONAR Y OEDEMA (restrictive) - Massive increase in mucus production - ↑↑↑ in goblet cells - Pleural effusion: abnormal fluid around the lung - Cilial function is lost (in the pleural cavity) - Abnormal dilation of the airways - Pulmonary oedema is fluid accumulation in the - Irreversible BRONCHIECTASIS lungs, which collects in air sacs NORMAL PULMONARY OEDEMA Question 5 A Salmeterol – Beta 2 agonist Lea, a 14-year-old female presents to her GP with shortness of breath and a dry cough. After further investigations, she is diagnosed with acute asthma. She is given an inhaler to help B Salbutamol – Beta 2 agonist relieve her symptoms. C Salbutamol – Beta 2 antagonist Given the above information, what is the most likely drug given and what is its mechanism of action? D Salmeterol – Beta 2 antagonist E Tiotropium – Muscarinic antagonistRESPIRTORY PHARMACOLOGY RESPIRA TOR Y DRUGS SHORT ACTING BOTH LONG ACTING • FLUTICASONE • SALMETEROL • SALBUTAMOL • IPRATROPIUM • Anti-inflammatory • TIOTROPIUM • Short acting steroid • Long-acting bronchodilators bronchodilators • Used alongside short • Salmeterol – moderate to • Used for acute acting and long-acting severe asthma resp. drugs • Tiotropium – COPD asthma/COPD management SALBUTAMOL (SABA) IPRATROPIUM (SAMA) FLUTICASONE SALMETEROL (LABA) TIOTROPIUM (LAMA) MOA: Selective B2 adrenergic MOA: Steroid glucocorticoid MOA: Muscarinic ACh receptor receptor agonist receptor complex antagonists - Activates B2 GPCR in bronchial - This complex acts as a tissue transcriptional regulator - Blocks M3 bronchial receptors - Activates adenylate cyclase and - Hence it strongly reduces - ACh can’t bind CAMP inflammation - Reduces CGMP - Causes bronchial SM relaxation - Smooth muscle relaxes - Bronchodilation occurs. - Bronchodilation occurs ADRs: ADRs: ADRs: - Long term immune suppression - Constipation - Angioedema - Cushing’s syndrome - Cardiac arrhythmias - Osteoporosis - Cough - Limb tremor - Diarrhoea - Hypokalaemia - Dry mouth CONTRA: - GI disturbance - Immunocompromised patients CONTRA: - Diabetics CONTRA: - CVD - Arrhythmias, cardiac failure, or MI - Arrhythmias - Low K+/hypokalaemic in last 6 months THANKS FOR WATCHINGPLEASE FILL OUT THE FEEDBACK FORM PLEASE TUNE IN TO OUR REMAINING SESSIONS THIS WEEK