All about pleural effusion :
- Definition
- Pathophysiology
- Causes/Etiology(Exudative and Transudative)
- Investigation methods
- Diagnostic approach
- Treatment
I. Definition of Pleural effusion :
This is the area between the lung and the chest wall that usually contains a thin layer of fluid that acts as a coupling mechanism. When there is an excess of fluid in the pleural space, it is called a pleural effusion.
II. What are the Pathophysiology of Pleural effusion :
There are two basic reasons for this: excessive pleural fluid production and reduced pleural fluid drainage.
- Excess formation of pleural fluid.
- Decreased drainage of pleural fluid.
III. What is the Causes of Pleural effusion :
There are mainly two types of Pleural effusion and they are – Transudative pleural effusion and Exudative pleural effusion.
Diseases/Syndromes which can cause transudative pleural effusion :
Extravascular fluid with low protein content and a low specific gravity (1.012) is known as transudate.
There are various causes for the formation of transudative pleural effusions, and they are :
- Nephrotic syndrome – Nephrotic syndrome is a kidney illness in which your body excretes an excessive amount of protein in your urine.
- Congestive heart failure/CHF – Congestive heart failure (CHF) is a chronic, progressive illness that decreases your heart muscle’s ability to pump blood.
- Superior vena cava/SVC obstruction – A constriction or blockage of the superior vena cava (SVC), the second biggest vein in the human body, is known as SVC obstruction.
- Cirrhosis of liver – Cirrhosis is a late-stage liver condition in which good liver tissue is replaced by scar tissue, causing permanent damage to the liver.
- Myxedema – Myxedema is another word for hypothyroidism that has progressed to an advanced stage. This is a condition that happens when your thyroid hormone production is insufficient.
- Urinothrix – Urinothorax (UT) is an uncommon and sometimes misdiagnosed illness characterised by the presence of urine in the pleural cavity as a result of the retroperitoneal leakage of urine accumulation (urinoma) into the pleural space.
- Peritoneal dialysis – When your kidneys can no longer efficiently eliminate waste items from your blood, peritoneal dialysis is used.
Diseases which can cause exudative pleural effusion :
1. Diseases related with gastrointestinal system :
- Diaphragmatic hernia
- Post abdominal surgery
- Intraabdominal disease
- Perforation of esophagus
- Endoscopic variceal sclerotherapy
- Post liver transplant
- Diseases of pancreas
2. Diseases related with collagen vascular abnormality :
- Drug-induced lupus
- Sjogren syndrome
- Churg-Strauss syndrome
- Rheumatoid pleuritis
- Systemic lupus erythematosus
- Granulomatosis with polyangiitis
3. Diseases related with Drugs :
- Dasatinib – This is a targeted therapy chemotherapeutic treatment used to treat chronic myelogenous leukaemia and acute lymphoblastic leukaemia in select circumstances.
- Nitrofurantoin – Nitrofurantoin is an antibiotic medicine that can be used to treat bladder infections, although it is less successful in treating kidney infections.
- Procarbazine – Procarbazine is a chemotherapeutic drug used to treat Hodgkin’s lymphoma and certain types of brain malignancies.
- Amiodarone – Amiodarone is an antiarrhythmic medicine that is used to treat and prevent a variety of cardiac rhythm disorders.
- Dantrolene – Dantrolene is a muscle relaxant used to treat muscle spasticity (stiffness and spasms) caused by spinal cord injuries, strokes, cerebral palsy, and multiple sclerosis.
- Methysergide – This is a monoaminergic drug that belongs to the ergoline and lysergamide families and is used to prevent and treat migraine and cluster headaches.
- Bromocripitine – This is a dopamine agonist and ergoline derivative that is used to treat pituitary tumours.
4. Diseases related with Infection :
- Bacterial diseases
- Fungal infections
- Viral infections
- Tuberculosis
- Parasitic infectons
5. Diseases related with Neoplasia :
- Metastatic disease
- Mesothelioma
6. Other important diseases :
- Asbestoses exposure
- Sarcoidosis
- Radiation therapy
- Post-cardiac injury syndrome
- Hemothorax
- Uremia
- Meigs’ syndrome
- Yellow nail syndrome
- Pulmonary embolisation
- Ovarian hyperstimulation syndrome
- Pericardial disease
- Chylothorax
- Post-coronary artery bypass surgery
- Trapped lung
- Iatrogenic injury
V. What are the Investigation methods of Pleural effusion :
Mainly are two types of Investigation procedures – Radiography and Laboratory procedure.
A. Radiography of pleural effusion :
- X-Ray – Localized effusions can be caused by scarring or adhesions in the pleural space. An raised hemidiaphragm is simulated by pleural fluid located below the lower lobe. Pleural fluid in an oblique fissure can appear as a rounded opacity, which can be mistaken for a tumour.
- CT Scan – Pleural biopsy with USG or CT guidance gives tissue for pathological and microbiological examination.
- USG – The presence of moving, floating densities suggests an exudate, while a clear hypoechoic gap indicates a transudate. Septation most likely implies an empyema that is progressing or a resolving haemothorax.
B. Laboratory tests of pleural effusion :
I. For exudative pleural effusion :
- Pleural fluid/ Serum protein > 0.5
- Pleural fluid LDH/Serum LDH >0.6
II. For transudative pleural effusion :
- Differential cell count
- Glucose level
- Fluid appearance
V. What is the diagnostic approach of Pleural effusion :
- At first we perform diagnostic thoracentesis, in which we measure level of the pleural fluid and LDH.
- Then we check three criteria – Serum protein > 0.5, Serum LDH >0.6, and LDH >2/3 of upper normal serum limit.
Based upon this data, we further proceed :
- If any of the above data is matched – Then the diagnosis is Exudative pleural effusion.
- If none of the above data is matched – The diagnosis is Transudative pleural effusion.
In exudative pleural effusion, we progress in further diagnosis, and these are :
- Measurement of pleural fluid glucose
- Culture and stain of pleural fluid
- Pleural fluid cytology
- Marker of pleural fluid for Tuberculosis
From the above criteria if Glucose level shows <60mg/dL, then we consider bacterial infections, malignancy, Rheumatoid pleuritis.
If from the above data, we diagnose nothing, then this should be considered as Pulmonary embolus.
If no Pulmonary embolus is detected, then the pleural fluid level for Tuberculosis is checked.
If still nothing is obtained and determined, then thoracoscopy or image-guided pleural biopsy is considered.
VI. What are the Treatment option of Pleural effusion :
- The underlying illness and whether the effusion is producing significant respiratory symptoms, such as shortness of breath or trouble breathing, determine the treatment for pleural effusion.
- Pleural effusion caused by congestive heart failure or other medical causes is treated with diuretics and other heart failure drugs.
- Chemotherapy, radiation therapy, or a drug infusion into the chest may be used to treat a malignant effusion.
- Using therapeutic thoracentesis or a chest tube, a pleural effusion that is causing respiratory difficulties can be drained (called tube thoracostomy).
- A sclerosing agent (a type of medicine that intentionally produces scarring) may be infused into the pleural cavity through a tube thoracostomy for individuals with uncontrollable pleural effusions that recur owing to a malignancy despite drainage (pleural sclerosis).
- Pleural sclerosis with sclerosing drugs (such as talc, doxycycline, and tetracycline) is 50% effective in preventing pleural effusions from recurring.
What is the surgical management of Pleural effusion :
Pleural effusions does not respond to drain, and sometimes pleural sclerosis may necessitate surgery.
There are mainly two types of surgery are available and they are – VATS and Thoracotomy.
A. VATS – Video assisted thoracoscopic surgery :
- A minimally invasive procedure that is carried out through one to three small (12-inch) incisions in the chest.
- This method, also known as thoracoscopic surgery, is beneficial in treating pleural effusions that are difficult to drain or that reoccur owing to cancer.
- To avoid the recurrence of fluid build-up, sterile talc or an antibiotic may be introduced at the time of surgery.
B. Importance of thoracotomy surgery :
- Traditional, “open” thoracic surgery is also known as thoracotomy.
- When pleural effusions are present and infection is prevalent, a thoracotomy is performed by a 6- to 8-inch incision in the chest.
- A thoracotomy is used to remove all fibrous tissue and help in the pleural area infection evacuation. To keep the fluid draining, patients will need chest tubes for 2 to 2 weeks after surgery.
- The surgeon will conduct a thorough examination of you in order to determine the safest treatment option for the patient, as well as outline the risks and benefits of each treatment option.