Respiratory Disease 1: History and Clinical Examination PDF

APPROACH TO R E S P I R ATO RY D I S E A S E 1 HISTORY AND CLINICAL E X A M I N AT I O N KIRSTY MCGINLEY FHEA MRCVS LECTURER IN VETERINARY CLINICAL SCIENCES LEARNING OBJECTIVES 1. Apply foundation anatomical and physiological knowledge as it relates to the cli...

APPROACH TO R E S P I R ATO RY D I S E A S E 1 HISTORY AND CLINICAL E X A M I N AT I O N KIRSTY MCGINLEY FHEA MRCVS LECTURER IN VETERINARY CLINICAL SCIENCES LEARNING OBJECTIVES 1. Apply foundation anatomical and physiological knowledge as it relates to the clinical evaluation of the respiratory system. 2. Detail a complete clinical assessment of the respiratory system. 3. Differentiate between disorders of the upper and lower respiratory tract based on clinical presentation. 4. Understand the range of diagnostic modalities available, and the rationale for their selection in the investigation of disorders of the respiratory system. A N AT O M Y O F T H E U P P E R R E S P I R AT O R Y T R A C T. Nares/Nasal Cavities. Paranasal sinuses. Nasopharynx. Larynx. Conduction zone. A N ATO M Y O F T H E L O W ER R ESPIR ATO RY TRACT. Trachea. Bronchi. Bronchioles. Lungs. Alveoli. Respiratory Zone. Where gas exchange occurs. P H Y S I O L O G Y O F R E S P I R AT I O N. TERMINOLOGY Eupnoea = Normal respiration. Tachypnoea = Increased respiratory rate (not necessarily depth), NOT panting. Dyspnoea = Difficulty breathing so technically incorrect. Orthopneoa = Inability to breath unless in an upright position. Apnoea = Absence of respiration. Hypoventilation/Hyperventilation = Alterations in ventilation at the alveolar level.  HISTORY Signalment – age, breed predispositions. When did it start? How did it start? Has it changed? This Photo by Has it happened before? Unknown Author is licensed under CC BY Vaccinated? Recent travel, change in management, others affected? Any other signs e.g., vomiting or diarrhoea? Any pre-existing conditions? Receiving medication? Trauma, toxin ingestion? O B S E R VAT I O N Initial observation from a distance whilst obtaining history. Will help when trying to determine location, URT vs LRT. Will alter respiration as soon as start clinical exam. Posture. Respiratory Rate. Respiratory effort and pattern. Normal inspiration – contraction of intercostal muscles and diaphragm, hardly visible. Normal expiration – completely passive, elastic recoil of compliant lung tissue. Secondary muscles of respiration become involved as respiratory drive increases. A U S C U LTAT I O N : R E S P I R ATO RY S O U N D S Always do a full nose to tail exam. craniodorsal caudodorsal Systematic evaluation of the airways Start at Hilus – over larger airways Don’t forget to listen over URT as well Hilus cranioventral Normal Bronchial - loud, high pitched, near hilus/over large airways. Vesicular - heard all over, especially on inspiration, more subtle “breeze through the trees”. Bronchovesicular – a mixture of the 2, similar duration during inspiration and expiration. Often very difficult to hear especially in large animals A U S C U LTAT I O N : R E S P I R ATO RY S O U N D S Abnormal/Adventitious. Enhanced by exercise, inducing cough, rebreathing. Wheezes – musical, expiratory, air passing through narrowed airways, e.g., Bronchial disease. Crackles - non-musical, intermittent, air passing through fluid e.g., pulmonary oedema. No sounds – no air movement e.g., pleural space disease/consolidated lung. PERCUSSION An adjunct to auscultation. Easier in larger animals. Assessing the resonance of air-filled structures. One hand flat on chest wall, other hand strikes the chest. Causes vibration of intrathoracic structures. Less resonant if fluid e.g., pleural effusion, more if air e.g., pneumothorax. Sinus percussion useful in horses to detect presence of fluid/masses. URT VS LRT Signs commonly associated URT disease. Occurring as a result of obstruction or inflammation of the upper airways. Sneezing. Nasal discharge. Noisy breathing (stridor and stertor). Altered respiratory patterns usually on inspiration. NASAL DISCHARGE Common clinical feature of respiratory disease. NASAL DISCHARGE Can be intermittent. Can be mixed. Unilateral vs Bilateral. N O I S Y B R E AT H I N G / A LT E R E D R E S P I R ATO RY PAT T E R N. URT VS LRT Signs commonly associated with LRT disease. Involving areas where gas exchange occurs. Coughing. Wheezing. Altered respiratory patterns (obstructive/increase expiratory effort; restrictive; paradoxical). Respiratory distress. COUGHING Activation of cough receptors by one or more of the following. Airway Inflammation. Airway secretions. Airway compression. Distinguish from gagging, choking, retching (Tracheal pinch). More cough receptors in larger airways. Tracheal involvement tends to results in harsher, drier, hacking cough (e.g., Kennel cough, tracheal collapse) Smaller airways/bronchioles softer, less efficient cough (e.g., bronchopneumonia, oedema). Breed and age really useful. e.g., Tracheal collapse – small breeds; Chronic bronchitis – adults. COUGHING A LT E R E D R E S P I R AT O RY PAT T E R N A LT E R E D R E S P I R ATO RY PAT T E R N A LT E R E D R E S P I R ATO RY PAT T E R N R E S P I R AT O RY D I S T R E S S If patients presents in respiratory distress will need to stabilise prior to full history and clinical examination. Priorities in acute respiratory distress. Establish an airway. Provide oxygen. Gain IV access.