Pleural Effusion (Etiology and Different Varieties)
Mar 01, 2023
Pleural effusion is a common clinical finding with many potential underlying causes. It refers to fluid accumulation in the pleural space between the lung and the chest wall. This condition can result from various underlying conditions, such as heart failure, pneumonia, cancer, tuberculosis, and kidney disease.
Knowledge of pleural effusion is essential for medical professionals as it can be a significant diagnostic and therapeutic challenge.
In this blog we’ll discuss the etiology and different varieties of pleural effusion is important medicine topic for NEET PG exam preparation.
Introduction
Normal amount of fluid in Pleural space: 5-15 ml
Pleural fluid secretedby: Parietal Pleura
Rate of synthesis of pleural fluid : 0.01 ml/kg/hr (Some of this secreted fluid is reabsorbed by lymphatics)
Minimal Amount of fluid present in pleural cavity for Clinical Detection → 300ml.
Minimal Amount of fluid that should be present to confirm pleural effusion on CXRin Upright position
CXR Upright : Lateral view > 100ml
CXR Upright : Frontal view > 200ml
CXR Upright : Frontal view (Amount of fluid needed for obliteration of Hemi-diaphragm: > 500 ml
Characteristic of Pleural effusion on CXR
Obliteration /Blunting of CP angle (CP Angle → Costophrenic Angle)
Meniscus sign
Etiology
2 types of PE
Transudative
Exudative
TRANSUDATIVE VARIETY
Hydrostatic Pressure will drive the fluid out of vascular space/capillaries while Oncotic pressure will drive the fluid back into Intravascular compartment
Any condition causing
Conditions causing ↑ in Hydrostatic Pressure
CHF (MC)
Constrictive Pericarditis
Valvular lesions
Conditions causing ↓ in Oncotic pressure
Oncotic Pressure α Blood Albumin
↓ Blood Albumin (HypoAlbuminemia) → ↓ Oncotic Pressure
Important information
Hypoalbuminemiais seen in conditions like
Cirrhosis
Nephrotic Syndrome
Protein Losing enteropathy
Transudative Pleural Effusion is always B/Las pressure is distributed equally to left & Right Side.
Leading cause of B/L Pleural effusion →Heart Failure
Fluid is transparent like water and Never Clots in Case of Transudate variety
Thoracocentesis
Thoracocentesis is always done USG guided
>1 cm distance b/w Pleural surface & lung border (i.e. 1 cm of Fluid separating Lung border from Pleural Surface) on CXR is an Indication of Doing Thoracocentesis
Preferred site of Thoracocentesis → 7th ICS (Inter Costal Space) in Scapular line
Different Varieties Of Pleural Effusion
Pleural Effusion related to Malignancy
Usually there is occurs Massive Pleural Effusion in Malignancy (peripherally located cancer)
Important information
Leading cause of Malignant Pleural Effusion → Ca Lung (Adenocarcinoma)
Leading cause of Malignant Ascites → Ca Ovary
Symptoms → Pt. C/O TREPEPNEA→ Dyspnea of Patient is Increasing on lateral Decubitus position.
Management
Diagnostic Thoracocentesis
Send the fluid to laboratory to confirm the Exudative variety based on LIGHT’s Criteria
Check for
Pleural Fluid Protein
Pleural Fluid LDH
Ideally any 1 of 3 present is sufficient for Diagnosis of Exudative Pleural Effusion.
However, in about 25% of cases light’s criteria may misdiagnose Transudate as Exudate.
Therefore we also check
Pleural fluid Sugar < 60 mg%
Cytology: Microscopic examination : Cancer Cells + nt
Pleural effusion in these cases of Malignancies recurs a lot after Thoracocentesis. To prevent this, we inject a sclerosing agent in pleural space which causes obliteration of pleural cavity and the fluid doesn’t reaccumulate. This procedure is k/as Pleurodesis
Rx: After Removing the fluid from pleural space, give the following drugs:
Injection Doxycycline Into pleural space via chest tube: Leads to formation of Adhesions in various layers of pleura ultimately causing Pleurodesis
Procedure of choice for Mx of patients with Malignant pleural effusion → Pleurodesis
Important information
Orthopnea: Breathlessness ↑ing in supine position
Seen in Acute CHF
Platypnea
↑ in Breathlessness in sittingposition
Seen in
Atrial Myxoma
Hepato pulmonary syndrome
Parapneumonic Effusion
If Diagnosed later or failed to Diagnose: Can lead to Empyemawhich then is managed by Chest tube insertion in 5th ICS in Mid Axillary line.
protein > 4.0 g/dL (may exceed 5 g/dL); eosinophils cells (> 10%) or mesothelial cells (>5%) make diagnosis unlikely: see text for additionaldiagnostic tests
Rheumatoid
Turbid; greenish yellow
1000-20,000 M or P
< 1000
< 40 mg/dl
Secondary empyema common; high LD, low complement, high rheumatoid factor, cholesterolcrystal areCharacteristic
Pulmonary infarction
serous to grossly bloody
1000-50,000 M or P
100 to100,000
equal to serum levels
variable findings: no pathognomonicfeatures
Esophageal rupture
turbid to purulent red- brown
< 5000 to50,000 P
1000-10,000
usually, low
high amylase level (salivary origin); pneumothorax in 25% cases; effusion usually on left side: pH< 6.0 strongly suggestsDiagnosis
Pancreatitis
Turbid to serosanguineous
1000-50,000 P
1000-10,000
equal to serum levels
Usually left- sided; highamylase level
GROSS APPEARANCE OF PLEURAL FLUID
A. Haemorrhagic pleural effusion
B. Chylous pleural effusion
c. Transudative Pleural effusion
Chylous Thoracic duct obstruction leads to Chylothorax: This Pleural Fluid isMilky White Colored and has ↑ Triglycerides
Cause of Chylothorax → Damage to lymphatics by Conditions such as Filariasis
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