Pleural Space Disease - MEF 2025 - PDF

PLEURAL SPACE DISEASE M EG HA N F IC K DV M, M S, DAC V EC C C L I N I C A L A S SI STA N T P RO F E S S O R O F E M E R G E N C Y A N D C R I T I C AL CA R E OFFICE: VMC 2107 E-MAIL: MEF [email protected]...

PLEURAL SPACE DISEASE M EG HA N F IC K DV M, M S, DAC V EC C C L I N I C A L A S SI STA N T P RO F E S S O R O F E M E R G E N C Y A N D C R I T I C AL CA R E OFFICE: VMC 2107 E-MAIL: MEF [email protected] PLEURA Pleura – pair of serous membranes (mesothelial cells) lining the thorax and lungs Parietal – Costal – Mediastinal (incomplete) – Diaphragmatic Visceral = Pulmonary PLEURAL SPACE Potential space – 0.1 ml/kg pleural fluid dogs – 0.3 ml/kg pleural fluid cats Function of fluid is to prevent friction during respiration CLINICAL SIGNS Mild to severe – Orthopnea – Dyspnea – Cyanosis Rapid, shallow breathing – Decreased lung expansion → reduced tidal volume PHYSICAL EXAM Dull or quiet heart and lung sounds – Depends on where the pathology is located in the pleural space Increased respiratory rate/effort PLEURAL SPACE DISEASE Air Fluid Transudate Modified Transudate Exudate Soft Tissue Diaphragmatic Hernia Mass (Neoplasia versus Granuloma versus Abscess) AIR = PNEUMOTHORAX – Traumatic Penetrating Blunt → transient increase in airway pressure and rupture of alveoli – Spontaneous Primary → pulmonary blebs or bullae (dogs) Secondary → neoplasia, abscesses, bacterial, parasitic or fungal pneumonia (dogs), lower airway disease, neoplasia, (cats) – Iatrogenic Needle or scalpel Barotrauma Traumatic intubation Feeding tube misplacement PNEUMOTHORAX GLIDE SIGN Glide sign is a NORMAL finding when the visceral and parietal pleural make contact during each respiration. LACK of a glide sign is suggestive of a pneumothorax TREATMENT Thoracocentesis Thoracostomy Tube Continuous Suction Blood Pleurodesis Lung Lobectomy FLUID = PLEURAL EFFUSION Net Fluid Flux = K[(Pc – Pi) –  (c - i)] K = Filtration coefficient  = Reflection coefficient (effectiveness of capillary wall in preventing passage of proteins) Pc = Capillary hydrostatic pressure Pi = Interstitial Fluid hydrostatic pressure c = Capillary colloid osmotic pressure I = Interstitial fluid colloid osmotic pressure PROMOTION OF PLEURAL EFFUSION Increase in capillary hydrostatic pressure – Transudate or modified transudate Decrease in capillary colloid osmotic pressure – Transudate or modified transudate Increase in permeability of capillary wall – Exudate Obstruction or disruption of lymphatic drainage DIAGNOSTICS Assessment of oxygenation Imaging – Thoracic Radiographs – TFAST – Echocardiogram DIAGNOSTICS Clinical Pathology – TP or TNCC – NT-proBNP – Cytology – Culture Imaging – Radiographs – Ultrasound/POCUS – CT  PURE TRANSUDATE (HYDROTHORAX) Decreased oncotic pressure Increased hydrostatic pressure MODIFIED TRANSUDATE Increased post-hepatic hydrostatic pressure – Heart failure Increased vascular permeability – Vasculitis – Lung lobe torsion – Diaphragmatic hernia Chronic effusions – Pleural irritation can cause increased cell count – Water can be reabsorbed in excess of proteins EXUDATES Feline Infectious Peritonitis Neoplastic Effusions Pyothorax Bilothorax Hemothorax Chylothorax FELINE INFECTIOUS PERITONITIS Coronavirus Aseptic exudative effusion Effusion usually present in more acute disease - but may be present terminally in non-effusive cats PATHOPHYSIOLOGY Infected macrophages deposited adjacent to small venules Forms pyogranulomas in affected tissues Inflammatory response can cause vasculopathy Effusion accumulates in body cavities DIAGNOSIS Pleural or peritoneal effusion – Viscous – Straw-colored – High protein (>3.5 gm/dL) – Low NCC High Serum Antibody Test (>1:1600) RT-PCR on effusion IHC on cells from effusion Rivalta Test Cats < 2 years of age Better when lymphoma or bacterial infections excluded Sensitivity 91.3% Specificity 65.5% PPV 58.4% NPV 93.4% NEOPLASTIC EFFUSIONS Transudates Exudates Hemothorax Pathogenesis … depends! – Increased vascular permeability – Tumor shedding or shedding of necrotic material – Lymphatic obstruction  HEMOTHORAX PCV (> 25%) – No true consensus on definition Etiology (Top 3) – Trauma – Coagulopathy – Neoplastic BILOTHORAX Rare Usually traumatic – Trauma vs. iatrogenic Diagnosis – Ratio of peripheral blood bilirubin to fluid bilirubin – > 1:1 ratio UROTHORAX I’m making this slide up because there wasn’t Same as bilothorax really info on it, but I’ve seen it once Same diagnostics as a Trauma Uroabdomen PYOTHORAX Dogs – migrating inhaled foreign bodies and traumatic thoracic penetration Cats – pulmonary infections, less commonly bite wounds PYOTHORAX Dogs – E. Coli and other members of the family Enterobacteriaceae – Pyogranulomatous infections = Actinomyces spp and Nocardia spp Cats – Pasteurella spp. CLINICAL SIGNS Pleural space disease Sepsis related signs related signs Tachypnea Fever Short, shallow breaths Lethargy Orthopnea Anorexia  Medical – Thoracocentesis – Chest Tube Placement – Antibiotics MANAGEMENT Surgical – Median Sternotomy – Copious Lavage – Antibiotics MEDICAL MANAGEMENT Broad Spectrum Antibiotics = Unasyn + Enrofloxacin – Resistance to enrofloxacin … amikacin and ceftizoxime?? – Clindamycin in cats Bilateral chest tubes – Pleural lavage Intermittent thoracocentesis is not recommended. It’s associated with a higher mortality rate in both dogs and cats.  Sterile Procedure Warm Saline PLEURAL 10-20 mL/kg every 6 hours LAVAGE Ensure close monitoring of ins/outs and fluid balance Can add heparin or tPA (humans) to decrease adhesions in pleural space CHEST TUBE MAINTENANCE MUST BE MAINTAINED STERILEY Should have site inspected and scrubbed daily Drain removal is usually < 2.2 ml/kg/day per tube dependent upon fluid production Can use imaging to assess fluid production  8 lab owned dogs Argyle chest tubes placed Daily CT and aspiration of TT Fluid first developed between days 2-6 3 dogs chewed out their TT… Bacterial culture positive in 6 dogs  36 cadavers Large bore or small bore thoracostomy tubes Air, low viscosity fluid, high viscosity fluid No significant difference in evacuation of any substance between the two groups  Medical management has good rate survival to discharge No clear benefits to surgical debridement and lavage without focal lesion PROGNOSIS Cats – 95% Dogs – 71-77% with medical with surgical management treatment CHYLOTHORAX Accumulation of chyle (lymph and emulsified fat) in the pleural cavity Forms in the small intestines Taken up by lacteals Travels from mesenteric lymphatics to thorax Results from impaired or obstructed lymphatic drainage CHYLOUS EFFUSION Characteristically large volume Milky to opaque appearance – Can be white to light pink Triglycerides are greater in the fluid than the serum Chylomicrons can be visible on wet prep CYTOLOGY Small lymphocytes predominate – May have low numbers of reactive or large lymphocytes May see neutrophils and macrophages with chronicity – May contain margined vacuoles in cytoplasm Sudan stain Abnormalities of lymphatic vessels Increased venous hydrostatic pressure (at the level of the right heart) Lung lobe torsion Abnormal organ positioning PATHOGENESIS PPDH Trauma?? Idiopathic (most common) DIFFERENTIAL DIAGNOSES Idiopathic Right sided heart disease Heartworm disease Neoplasia Lung lobe torsion Thrombosis Trauma Less Commonly … fungal granuloma, PPDH, Iatrogenic…  DIAGNOSTIC T H OR A C O C E N T E SI S INDICATIONS Signs of respiratory distress (increased respiratory effort) + reduced breath sounds Performed before thoracic radiographs Very sensitive test Can proceed to therapeutic if necessary without thoracic radiographs MATERIALS 3 ml syringe 22 gauge 1” needle  POSITIONING Standing Sternal recumbency Lateral recumbency Sitting will make it difficult to isolate landmarks… POSITIONING AND PREP  Pneumothorax → – 7th to 9th intercostal space – Highest part of the chest Pleural Effusion → – 7th to 9th intercostal space – Lowest part of the chest  Advance the needle through the skin Pull back on the plunger to apply vacuum once through the subcutaneous tissue Do not release the vacuum!  ADVANCE THE NEEDLE THROUGH THE CHEST UNTIL YOU LOSE THE VACUUM  T H ER A P E U T I C T H OR A C O C E N T E SI S INDICATIONS Previously identified clinically significant pleural fluid or air Used to remove fluid or air in distressed patients  Butterfly catheter Short intravenous TECHNIQUES catheter Fenestrated plastic intravenous catheter BUTTERFLY TECHNIQUE 35-60 ml syringe 3 way stopcock 19 gauge or 22 gauge winged needle catheter M ATE R I ALS Clippers & skin prep Lidocaine for local anesthesia 20, 35 or 60 ml syringe with stopcock and IV extension #11 scalpel blade 3 ml empty syringe Catheter – – Cats → 16-20 gauge – Dogs → 14-18 gauge CATHETER SET-UP  POSITIONING Sternal recumbency Do not force into lateral! Use more severe hemithorax  Pneumothorax → – 7th – 8th intercostal space – Junction of dorsal and middle thirds of lateral chest wall Pleural Effusion – 7th – 8th intercostal space – Just above costochondral junction LOCAL ANESTHESIA Block desired location with lidocaine to the depth of the pleura Aspirate to withdraw air or fluid into the syringe Inject into pleura as needle is withdrawn Mark with an ‘X’ PREPARATION Aseptically scrub with chlorhexidine for dogs and betadine or povidone iodine for cats Continuous contact for 3 minutes before removing with alcohol Tent the skin away from the body wall vertically Make a stab incision into the site with the lidocaine block Stab completely through the dermis ATTACH A 3 ML SYRINGE TO THE CATHETER ADVANCE INTO SUBCUTANEOUS SPACE APPLY 1-2 ML OF VACUUM TO SYRINGE ONCE IN SUBCUTANEOUS TISSUE ADVANCE ENTIRE CATHETER AND STYLET A FEW MILLIMETERS  ADVANCE CATHETER A FEW MILLIMETERS OFF OF STYLET  ANGLE CRANIALLY ADVANCE CATHETER OFF STYLET  ATTACH COLLECTION SET TO END OF CATHETER PRE AND POST TUBE PLACEMENT DIAPHRAGMATIC HERNIA Usually traumatic (85%) Supportive Oxygen Therapy IVC and Fluid Therapy if in shock Surgical Intervention Textbook of Small Animal Emergency Medicine WHAT IS THE FIRST STEP FOR ALL THESE PATIENTS? Stabilize!! Oxygen therapy Anxiolysis  [email protected] 77