Pleural effusion and empyema - Sibu Binqela.pdf

APPROACH TO PLEURAL EFFUSIONS AND EMPYEMA Sibulele Binqela 14/06/2024  PLURAL EFFUSION De nition: excessive accumulation of uid in the pleural space Pleura origin → embryonic mesoderm Differentiate into parietal and visceral pleura by week 3 of gestation Two layers me...

APPROACH TO PLEURAL EFFUSIONS AND EMPYEMA Sibulele Binqela 14/06/2024  PLURAL EFFUSION De nition: excessive accumulation of uid in the pleural space Pleura origin → embryonic mesoderm Differentiate into parietal and visceral pleura by week 3 of gestation Two layers merge at pulmonary ligament = non-contiguous hemi-thoraces Parietal – supplied by branches of intercostal arteries Visceral – supplies by branches from bronchial arteries In adult Surface area 2000cm2 Pleural space 10-20µm wide Contains 8-10ml uid Negative pressure within pleural cavity: -3 to -5 cmH20 fi fl fl NORMAL PHYSIOLOGY Ultra- ltrate of parietal pleural capillaries Increased interstitial pressure → movement of uid into pleural space through mesothelial cell junction → through stomata in parietal pleura → through lymphatic channels into LNs Rate of production 0.01ml/kg/h Rate of absorption 0.28ml/kg/h Function of parietal pleura PF formation must increase >30-fold for a clinically signi cant effusion to develop fi fl fi  Evaluation of the patient with pleural effusion is challenging, because the differential diagnosis is broad and includes both benign and life-threatening conditions. History taking: suggestive of respiratory infection, malignant disease and autoimmune diseases, heart, liver and renal diseases. risk factors for tuberculosis Signs and symptoms of an effusion vary depending on the underlying disease, but dyspnea, cough, and pleuritic chest pain are common. CLINICAL FINDINGS Chest examination of a patient with pleural effusion is notable for: dullness to percussion decreased or absent tactile fremitus decreased breath sounds no voice transmission. CXR Posteroanterior and lateral chest radiographs usually con rm the presence of a pleural effusion, On PA blunt the costophrenic angle form a meniscus laterally hide in a subpulmonic location, simulating an elevated hemidiaphragm: pleural effusions that can be seen only on an erect projection and pleural uid lies almost exclusively between the lung base and the diaphragm Small amounts of pleural uid not readily seen on the standard frontal view may be recognized in a lateral decubitus view can visualize small amounts of uid layering against the dependent parietal pleura. If doubt exists, ultrasound or computed tomography (CT) scans are de nitive for detecting small effusions and for differentiating pleural uid from pleural thickening. fl fl fi fi fl fl CXR CXR PA of Subpulmonic effusion Lateral decubitus CXR ULTRASOUND L pleural effusion R Pleural effusion CT CHEST MEASURING EFFUSIONS USING A) LATERAL DECUBITUS CXR, B) LATERAL ERECT CXR AND C) CHEST CT B.K. Moffett et al. Eur Respir J 2011;38:1406-1411 THOROCENTESIS ?WHO GETS TAPPED Except for patients with obvious heart failure, thoracentesis should be performed in all patients with more than a minimal pleural effusion (i.e., larger than 1 cm height on lateral decubitus radiograph, ultrasound, or CT) of unknown origin In the context of heart failure, diagnostic thoracentesis is only indicated if any of the following atypical circumstances is present: the patient is febrile or has pleuritic chest pain; the patient has a unilateral effusion or effusions of markedly disparate size; the effusion is not associated with cardiomegaly, or the effusion fails to respond to management of the heart failure THORACENTESIS Observation Small effusions (0.75) Histology - granulomatous in ammation ± caseation in ~80% of patients ADA >40 GXP and culture con rms TB diagnosis >95% of cases Smear microscopy – poor yield (50%; higher in HIV, loculated/ neutrophilic effusions Con rm TB elsewhere: sputum, ULAM etc Xpert/M.TB Rif – 50% sensitivity, high speci city Sputum plus pleural uid cultures has a combined diagnostic yield of about 80% Xpert Ultra – 75% sensitivity, high speci city fi fl fl fi fl fi fi EMPYEMA When microorganisms infect the pleural space, a complicated parapneumonic effusion or empyema may result Parapneumonic effusion is a pleural effusion that forms in the pleural space adjacent to a pneumonia. uncomplicated or simple parapneumonic effusion refers to a free- owing effusion that is sterile complicated parapneumonic effusion refers to an effusion that has been infected with bacteria or other microorganisms Empyema: collection of pus within the pleural space, which can develop when pyogenic bacteria, fungi, parasites, or mycobacteria invade the pleural space, either from an adjacent pneumonia or from direct inoculation (eg, from penetrating trauma Complex – internal loculations (septae) Uniloculated – without internal septae (free- owing or xed) An empyema can also develop in the absence of an adjacent pneumonia. fl fi fl  CAUSES IN THE ABSENCE OF PNEUMONIA 1.Oesophageal rupture, 6.infected congenital cysts of the airway or esophagus, 2.blunt or penetrating chest trauma, 7.extension from sources outside the thorax 3.hematogenous spread, (eg, liver abscess or cervical or thoracic spine infections). 4.mediastinitis with pleural extension 8.Postsurgical etiologies (eg, bronchopleural 5.bronchogenic carcinoma that has breached stula from lobectomy) can also be the pleura allowing bacterial translocation, independent of pneumonia. fi RISK FACTORS FOR EMPYEMA Age under 60 years old Poor oral hygiene Disorders with a predisposition to aspiration (seizure, alcohol use disorder, central nervous system disease) IV drug misuse Diabetes Cardiovascular disease Liver cirrhosis Other immunocompromised states (HIV infection, malignancy)  PATHOGENESIS Exudative stage - Initial bacterial infection causes an acute in ammatory response between the pulmonary parenchyma and visceral pleural Proin ammatory cytokines cause increased capillary permeability, leading to an in ux of neutrophil-rich uid into the pleural space. resolves with appropriate antibiotic treatment, and does not warrant invasive drainage. Fibrinopurulent and Loculated stage—In the absence of appropriate treatment, the effusion can become complicated by the deposition of brin clots and membranes, resulting in isolated collections of uid in the pleural space. effusion warrants antimicrobials and drainage. Chronic Organizational stage - if not drained, broblasts coalesce to form a thick pleural peel between the visceral and parietal pleura. inhibiting adequate gas exchange, trapped lung, or chronic forms of empyema. fl fi fi fl fl fl fl MICROBIOLOGY Spectrum of potential pathogens is wide and varies based on the route of acquisition (eg, parapneumonic versus nonparapneumonic), site of acquisition (eg, community or hospital-acquired) and geography Pyogenic bacteria Streptococcus pneumoniae, oral streptococci and anaerobes, and Staphylococcus aureus are the most common causes Methicillin-resistant Staphylococcus aureus (MRSA) and gram negatives, including Pseudomonas and Enterobacteriaceae, are pathogens commonly seen in hospital-acquired empyema Mycobacteria: reactivation of latent tuberculosis (TB) in the subjacent lung or pleural space. Other pathogens: Fungal: Candida disseminated infections in highly immunocompromised patient or a complication of thoracic surgery Parasites: Entamoeba histolytica, Echinococcus granulosus and Paragonimus westermani c MICRO THORACENTESIS Frank pus Uncertainty: biochemical analysis of pleural uid support the diagnosis of empyema pH less than 7.2 measured via a blood gas analyze Polymorphonucleocyte predominance, Low glucose LDH over 1000 Pleural uid should be inoculated directly into blood culture bottles (aerobic and anaerobic) in addition to the usual sterile containers used for standard Gram stain and culture, in order to maximize diagnostic yield fl fl MANAGEMENT Thoracostomy (ICD): complicated pleural effusions and empyema Empyema (ie, overtly purulent pleural uid) Positive pleural uid Gram stain or culture Loculated pleural effusion Large free- owing effusions (ie, ≥0.5 hemithorax) Effusions associated with thickened parietal pleura Sepsis from a pleural source Not inserting ICD: Poor outcomes, , longer hospitilization, requirement for more than one procedure and eventual need for surgery fl fl fl MANAGEMENT Adequate antibiotic coverage Led by culture results Empiric treatment for community acquired: Amoxicillin/clavunate 1.2g ( IVI 8 hrly Cefttriaxone 1g IVI daily + Metronidazole 500mg IVI 8 hrly Pen allergy: moxi oxacin 400mg IVI/PO + metronidazole Hospital-acquired Led by hospital MSSA/MRSA rates Should cover Staph Aureus and Gram Neg bacteria Call ID fl MANAGEMENT: Intrapleural brinolytic: Indications: omplicated parapneumonic effusion or empyema who fail antibiotic therapy and initial drainage. It is also a suitable option in patients who are not candidates for or do not want surgery The data has been underwhelming and has shown no profound bene t in patient outcomes or need for surgical intervention Combination therapy of brinolytic agents and mucolytics, particularly TPA–DNase therapy, improved uid drainage for patients with pleural infection and reduced the frequency of surgical referral Intrapleural irrigation approach using saline lavage The Pleural Irrigation Trial (PIT) found radiographic improvement after three days vs. standard of care fi fi fi fl Drainage via tube thoracostomy fails or multi-loculated empyema: surgical consult for Video-assisted thoracoscopic surgery (VATS) is a minimally invasive surgical technique that allows for direct visualization and evacuation of the infected pleural space. Similar morbidity and shorter hospital say compare to thorocotomy Open Thoracostomy and Decortication: Persistent empyema refractory to standard therapies, including VATS, COMPLICATIONS secondary to the underlying disease process, and patients may succumb to worsening sepsis, septic shock, or death. Secondary to incomplete drainage due to tube malposition or malfunction pneumothorax, bronchopleural stulas pleural brosis with subsequent trapped lung fi fi THANK YOU REFERENCES https://sso.uptodate.com/contents/management-and-prognosis-of-parapneumonic-pleural-effusion-and- empyema-in-adults? search=empyema&source=search_result&selectedTitle=2%7E150&usage_type=default&display_rank=2# H1750918943 https://www.ncbi.nlm.nih.gov/books/NBK544279/ #:~:text=%5B16%5D%20The%20goals%20of%20therapy,by%20open%20thoracostomy%20and%20decorti cation. https://www.uptodate.com/contents/pleural- uid-analysis-in-adults-with-a-pleural-effusion#H3613609040 https://www.aafp.org/pubs/afp/issues/2006/0401/p1211.html#afp20060401p1211-b10 fl