Diseases of the Pleural Space and Chest Wall (Veterinary) PDF

DISEASES OF THE P L E U R A L S PA C E A N D CHEST WALL KIRSTY MCGINLEY FHEA MRCVS S L I D E S C O U R T E S Y O F S H O N A M C I N T Y R E LEARNING OUTCOMES Describe the pathological issues of pleural space and chest wall Describe diagnostic procedures and therap...

DISEASES OF THE P L E U R A L S PA C E A N D CHEST WALL KIRSTY MCGINLEY FHEA MRCVS S L I D E S C O U R T E S Y O F S H O N A M C I N T Y R E LEARNING OUTCOMES Describe the pathological issues of pleural space and chest wall Describe diagnostic procedures and therapeutics of pleural space and chest wall Describe management of pleural space and chest wall disorders W H AT I S T H E P L E U R A L S PA C E The pleural cavity is a potential compartment separating the chest wall, lungs, diaphragm and mediastinum.  A P P R O A C H TO T H E D Y S P N O E I C PAT I E N T History and physical exam Minimise stress. Carry out swiftly. ‘Hands off approach’. May be incomplete until animal more stable. Monitor RR. Can you hear lung sounds? Initial treatment Oxygen therapy. IV access. Pain relief. Butorphanol (if no trauma). Thoracocentesis. Stabilise before embarking on diagnostics THE DYSPNOEIC ANIMAL THE DYSPNOEIC ANIMAL DIAGNOSTICS Diagnostic Imaging DIAGNOSTICS Diagnostic Imaging Courtesy of improve veterinary practice DIAGNOSTICS Diagnostic Imaging – TFAST Ultrasound Sites Chest tube site (CTS) 7th – 9th intercostal space on dorsolateral thoracic wall Pericardial site (PCS) 5th – 6th intercostal space on ventrolateral thoracic wall Diaphragmaticohepatic view (DH) Just behind the xiphoid process with the probe directed cranially To see a video on how to perform TFAST https://www.youtube.com/watch?v=rRJharpGxns&t=354s DIAGNOSTICS Thoracocentesis Indications Used to remove fluid or air from pleural space. Can be diagnostic or therapeutic. Equipment Butterfly needle (16-21G), 3-way tap, syringe. Measuring bowl. Local anaesthetic? Patient Preparation Keep patient comfortable – sternal recumbency. Sterile technique. Shave area with 15cm radius to proposed site. Aseptic preparation. DIAGNOSTICS Thoracocentesis DIAGNOSTICS Thoracocentesis – fluid analysis Remember to look at gross characteristics. Pyothorax or FIP may be diagnosed on fluid characteristics alone. A modified transudate is non-specific so consider in light of other data. D I F F E R E N T I A L S FO R P L E U R A L S PA C E D I S EA S E Pneumothorax Trauma or spontaneous Open, Closed, Tension Haemothorax Trauma, Coagulopathy, Neoplasia Chylothorax Idiopathic, Trauma, Congestive heart failure Pyothorax Foreign body, Penetrating trauma, Secondary to pneumonia Other effusions Congestive heart failure, Feline Infectious Peritonitis, Neoplasia Space occupying lesions Diaphragmatic hernia Neoplasia (most commonly mediastinal lymphoma) PNEUMOTHORAX Air in the pleural space Air originates from respiratory tract or oesophagus, or enters via penetrating wound / trauma PNEUMOTHORAX  PNEUMOTHORAX Treatment Thoracocentesis / Thoracotomy tube. Pain medication / sedation. Oxygen therapy. Antibiotics if penetrating trauma. Radiographs to confirm resolution. Surgery Prognosis for conservative management of closed: guarded. Thoracotomy following CT to confirm location lesions. HAEMOTHORAX Blood in the pleural space Causes Trauma. Coagulopathy – primary or secondary. Neoplasia. Further Diagnostics Need to identify underlying cause as will affect prognosis. Biochemistry / haematology. Coagulation testing. Look for signs bleeding elsewhere like petechiae. Treatment Treat hypothermia / hypovolaemia. Blood transfusion? Pain relief. Treat underlying cause CHYLOTHORAX What is it? Milky effusion. Fat droplets, lymphocytes, neutrophils. Cholesterol similar to serum levels. Triglyceride higher than serum levels. Causes Idiopathic. Damage to thoracic duct – traumatic rupture, obstruction. Lung lobe torsion, mediastinal masses. Heart disease. Diaphragmatic rupture. Siamese, Himalayan cats and Afghan hounds over- represented. CHYLOTHORAX Treatment Thoracocentesis. Often idiopathic but can treat underlying cause. Low fat diet? Surgical duct ligation.  PYOTHORAX Purulent fluid in the pleural space Causes Foreign body (grass seed, penetrating wound). Bite wound (cats). Pneumonia (uncommon). Diagnosis Appearance and smell! Degenerate neutrophils and intracellular bacteria. Treatment Thoracic drainage (thoracostomy tube) and lavage. Surgical FB removal. Antibiotics. Long and expensive. Prognosis Guarded. THORACOSTOMY TUBE Indications Patient Preparation Frequent drainage chest required. Pre-oxygenate patient. Medical management of pyothorax. Local or general anaesthetic. Following thoracic surgery. Equipment Chest tube 3-way tap, clamp, syringe Scalpel Local anaesthetic Suture material Sterile dressing Elizabethan collar THORACOSTOMY TUBE PLACEMENT THORACOSTOMY TUBE MANAGEMENT Constant monitoring. Ensure safety tube and connectors. Avoid patient interference. Check for change in respiratory rate and pattern. Drain every 4 hours for 24-48 hours then 2-3 times daily. Use thoracic lavage with 0.9% sodium chloride or Hartmann’s solution. Change dressing and check connectors daily. If appears non-functional can flush. Remove once fluid production reduced to 2-4ml/kg/day. Cover sterile dressing once removed. D I A P H R A G M AT I C H E R N I A Displacement of organs into the thoracic cavity. Empty appearance of the abdomen. Intestinal content in the thorax. D I A P H R A G M AT I C H E R N I A Clinical signs Dyspnoea Muffled heart and lung sounds Intestinal sounds in chest ‘empty’ abdomen – abnormal on palpation Treatment Stabilise patient Surgery Abdominal approach Will need IPPV Must drain pneumothorax on closure Image courtesy of clinicians brief DIFFERENTIALS FOR CHEST WALL INJURY Trauma (RTA). Flail chest. Open pneumothorax. Penetrating trauma. Bite wounds. FLAIL CHEST Freely moving section of chest wall secondary to consecutive rib fractures Potential complication of trauma Clinical signs Tachypnoea, dyspnoea Thoracic pain Paradoxical movement of flail segment Subcutaneous emphysema Treatment Emergency stabilisation Chest bandage Aggressive pain management Surgical stabilisation FLAIL CHEST DOG BITES Thorax is common location. External wound often ‘tip of the iceberg’. Treatment. Potential complications: Surgical exploration. Crushing of thorax. Flush wound for culture and sensitivity. Rib fractures. Lung laceration. Pain relief. Intercostal muscle avulsion. May require thoracic drainage. Bacterial inoculation into wound. Stabilisation. Overall, thoracic bite wounds have a reported mortality Start antimicrobials early. rate of 12.5 to 27 percent and post-operative complications have been associated with poorer outcome. Protective dressing until definitive treatment. (Scheepens et al., 2006). TFAST to ensure no pleural effusion/pneumothorax. Radiography to assess for fractures. SUMMARY Take a logical approach to animals presenting with respiratory compromise Less is more when handling and on initial stabilisation Thoracocentesis can be a diagnostic and therapeutic tool Remember the role of ultrasound in the diagnosis of pleural fluid or chest wall masses.