1

Question 1

What is the primary aim of the World Journal of Clinical Cases (WJCC)?

Answer 1

To provide a platform for scholars and readers in clinical medicine to publish high-quality clinical research articles and communicate their research findings online.

Question 2

What types of articles does WJCC mainly publish?

Answer 2

WJCC publishes articles reporting research results and findings in clinical medicine, including case control studies, retrospective cohort studies, clinical trials, observational studies, systematic reviews, meta-analyses, and case reports.

Question 3

In what databases is the WJCC abstracted and indexed?

Answer 3

The WJCC is abstracted and indexed in Science Citation Index Expanded (SCIE), Journal Citation Reports/Science Edition, Current Contents/Clinical Medicine, PubMed, PubMed Central, Scopus, and other databases.

Question 4

What was the 2021 impact factor (IF) for WJCC according to the 2022 Edition of Journal Citation Reports?

Answer 4

The 2021 impact factor for WJCC was 1.534. The IF without journal self cites was 1.491, and the 5-year IF was 1.599.

Question 5

When was the World Journal of Clinical Cases launched?

Answer 5

April 16, 2013

Question 6

How often is the World Journal of Clinical Cases published?

Answer 6

Thrice Monthly

Question 7

What is the online ISSN of the World Journal of Clinical Cases?

Answer 7

ISSN 2307-8960 (online)

Question 8

What is the definition of pleural effusion?

Answer 8

Pleural effusion is the accumulation of fluid in the pleural space, which is the area between the parietal pleura (lining the chest wall) and the visceral pleura (covering the lung surface).

Question 9

What is the normal amount of pleural fluid in the pleural space?

Answer 9

Normally, the pleural space contains about 0.1-0.2 mL/kg of pleural fluid.

Question 10

What is the function of the pleura and pleural cavity?

Answer 10

The pleura and pleural cavity facilitate lung inflation and deflation by reducing friction against the chest wall and transmitting the force produced by respiratory muscles to the lungs.

Question 11

What is the normal pH and protein content of pleural fluid?

Answer 11

The pleural fluid pH is usually alkaline (pH 7.6) with low protein content (less than 1.5 g/dL).

Question 12

How does Starling’s equation describe pleural fluid turnover?

Answer 12

Starling’s equation describes pleural fluid turnover as: Jv = Kf[(HP1 - HP2) - σ(π1 - π2)], where Jv is the water flux, Kf is the filtration coefficient, HP and π are the hydrostatic and colloid osmotic pressures, and σ is the solute reflection coefficient.

Question 13

What are the two main processes involved in pleural fluid cycling?

Answer 13

The two main processes are parietal pleural fluid filtration and parietal lymphatic drainage.

Question 14

How does inflammation or neoplasm affect protein reabsorption in the pleural space?

Answer 14

Inflammation or neoplasm affecting the parietal pleura decreases protein reabsorption, leading to altered fluid hydrodynamics and increased effusion size.

Question 15

How does pleural effusion affect lung function?

Answer 15

Pleural effusion induces a restrictive lung function pattern with reduced vital capacity, total lung capacity, and functional residual capacity, potentially leading to hypoxemia.

Question 16

How does pleural effusion affect hemodynamics?

Answer 16

Pleural effusion increases intrapleural pressure, leading to lung collapse and increased pulmonary vascular resistance, which can result in right ventricular failure.

Question 17

What are the main types of pleural effusions based on fluid type?

Answer 17

The main types are transudate, exudate, hemothorax, chylothorax, and pseudo-chylous effusion.

Question 18

What are the characteristics of transudative pleural effusion?

Answer 18

Transudative fluid has low protein content due to an imbalance between hydrostatic and oncotic pressure, leading to increased fluid entrance into the pleural cavity.

Question 19

What are the characteristics of exudative pleural effusion?

Answer 19

Exudative fluid has high protein content due to pleural injury, increased pleural membrane permeability, and/or fluid extravasation from blood vessels.

Question 20

What is hemothorax and its common causes?

Answer 20

Hemothorax is the accumulation of blood in the pleural space, often resulting from chest trauma or surgery.

Question 21

What is chylothorax and its common causes?

Answer 21

Chylothorax is the accumulation of lymph in the pleural cavity, often resulting from malignancy or trauma involving the lymphatic channels, especially the thoracic duct.

Question 22

What is pseudo-chylous effusion and its common causes?

Answer 22

Pseudo-chylous effusion occurs due to long-standing pleural effusion, mostly secondary to rheumatoid diseases, and contains a large quantity of lipids without chylomicrons.

Question 23

What are the initial steps in diagnosing pleural effusion?

Answer 23

Diagnosis starts with a detailed history and physical examination, including assessment of exposures, past infections, underlying diseases, and related symptoms.

Question 24

What are the typical symptoms of pleural effusion?

Answer 24

Symptoms include cough, pleuritic chest pain, and dyspnea, though patients may be asymptomatic.

Question 25

What are the physical examination findings associated with pleural effusion?

Answer 25

Physical examination reveals reduced tactile vocal fremitus, stony dullness on percussion, and diminished or absent breath sounds.

Question 26

What are the classic radiological findings of pleural effusion on a chest X-ray?

Answer 26

Obliteration of the costo-phrenic angle and homogeneous opacity rising toward the axilla with no air bronchogram.

Question 27

How does pleural effusion appear on ultrasonography?

Answer 27

Pleural effusions appear as an echo-free space between the visceral and parietal pleura.

Question 28

What information can be obtained from ultrasonography of pleural effusion?

Answer 28

Ultrasonography can assess fluid nature, confirm loculations, estimate fluid volume, measure pleural thickness, diagnose pleural masses, identify fluid viscosity, and guide thoracentesis and pleural biopsy.

Question 29

How does CT scanning aid in the diagnosis of pleural effusion?

Answer 29

CT scans can visualize interlobar and para-mediastinal pleura, guide pleural biopsy and drain placement, differentiate benign from malignant pleural thickening, and diagnose pulmonary embolism.

Question 30

When is diagnostic pleural fluid aspiration indicated?

Answer 30

It is indicated in the presence of an undiagnosed etiology of significant pleural effusion (thickness >1 to 2 cm) unless congestive heart failure is the most probable cause.

Question 31

What is the utility of Light's criteria in assessing pleural fluid?

Answer 31

Light’s criteria, based on serum and pleural fluid protein and lactate dehydrogenase (LDH), help assess the fluid as transudate or exudate to simplify differential diagnosis.

Question 32

What pleural fluid values can guide the diagnosis of its cause?

Answer 32

Pleural fluid cellular pattern, presence of malignant cells, glucose, amylase, cholesterol, pH, chylomicrons, and adenosine deaminase (ADA) levels can guide diagnosis.

Question 33

When is pleural biopsy indicated?

Answer 33

Pleural biopsy is indicated for exudative pleural effusion cases that remain undiagnosed after thoracentesis.

Question 34

What are the different types of pleural biopsy?

Answer 34

The biopsy can be either closed needle biopsy, image-guided (percutaneous pleural biopsy), or thoracoscopic biopsy.

Question 35

What other investigations can help diagnose pleural effusion?

Answer 35

Other investigations include electrocardiography, echocardiography, N-terminal-B-type natriuretic peptide, abdominal imaging, urine analysis, gastrointestinal endoscopies, liver and kidney function tests, and tumor markers.

Question 36

What are Light's criteria for differentiating between exudative and transudative pleural effusion?

Answer 36

Pleural fluid is considered exudate if pleural fluid/serum protein > 0.5, pleural fluid/serum LDH > 0.6, or pleural fluid LDH > two-thirds of upper limits of the laboratory’s normal serum LDH.

Question 37

What are some pleural fluid only dependent criteria for differentiating between exudative and transudative pleural effusion?

Answer 37

Pleural fluid is considered exudate if Pleural fluid protein ≥ 3 gm/dL, or pleural fluid cholesterol > 45 mg/dL, or pleural fluid LDH > 0.45 times the upper limit of the laboratory’s normal serum LDH.

Question 38

What does a lymphocyte count > 85% in pleural fluid suggest?

Answer 38

It suggests tuberculous pleural effusion, sarcoidosis, chronic rheumatoid pleurisy, yellow nail syndrome, or chylothorax.

Question 39

What does a neutrophil count > 10000 / μL in pleural fluid suggest?

Answer 39

It suggests para-pneumonic effusion, lupus pleuritis, or acute pancreatitis.

Question 40

What does a pleural fluid pH < 7.3 suggest?

Answer 40

It suggests esophageal rupture, chronic rheumatoid pleurisy, complicated para-pneumonic effusion, paragonimiasis, amoebic empyema, tuberculous pleural effusion, lupus pleuritis, urinothorax, or pancreatic-pleural fistula.

Question 41

What does elevated pleural fluid amylase suggest?

Answer 41

It suggests esophageal rupture, acute pancreatitis, or pancreatic-pleural fistula.

Question 42

What does the presence of chylomicrons in pleural fluid indicate?

Answer 42

It indicates chylothorax.

Question 43

What is the significance of pleural effusion in the ICU setting?

Answer 43

The cause of ICU admission is often the underlying cause of the pleural effusion, and the size of pleural effusion is usually larger in ICU patients.

Question 44

Why is there impaired turnover of pleural fluid in critically ill and mechanically ventilated patients?

Answer 44

Impaired turnover is due to factors like prolonged recumbent position, ventilator-produced positive pressure, and elevated intra-abdominal pressures, which disturb the balance between parietal pleural fluid filtration and lymphatic drainage.

Question 45

How does positive pressure ventilation affect pleural fluid cycling?

Answer 45

Positive pressure impairs the balance between hydrostatic and oncotic pressure gradients and disturbs the normal rhythmogenecity of lymphatics responsible for pleural fluid removal.

Question 46

How does systemic inflammation affect pleural fluid filtration?

Answer 46

Systemic inflammation leads to capillary leak, reducing the reflection coefficient and increasing both fluid and solute filtration.

Question 47

What factors hinder the diagnosis of pleural effusion in the ICU?

Answer 47

Factors include masking of symptoms by other severe conditions, difficulty in obtaining an erect chest radiogram, and chest wall edema.

Question 48

What is the most reliable method to diagnose and monitor pleural effusion in the ICU setting?

Answer 48

Chest ultrasonography is the most reliable method due to its high sensitivity, ease of use, and lack of radiation exposure.

Question 49

How does the presence of pleural effusion affect the prognosis and outcome in critically ill patients?

Answer 49

Pleural effusion can lead to worse outcomes due to its impact on hemodynamic and lung mechanics in patients with comorbidities and under mechanical ventilation.

Question 50

How can analysis of aspirated pleural fluid during thoracentesis help in the ICU?

Answer 50

It helps diagnose the effusion type and the initial condition causing ICU admission, potentially changing the diagnosis and modifying the treatment strategy.

Question 51

What are the benefits of pleural fluid drainage in critically ill and mechanically ventilated patients?

Answer 51

Drainage can improve oxygenation status, reduce work of breathing, and reduce respiratory rate, improving the patient’s prognosis.

Question 52

What are the common methods used to drain pleural fluid in the ICU setting?

Answer 52

Thoracentesis and chest drain placement (either a standard intercostal tube or a small-bore drain like a pigtail catheter) are commonly used.

Question 53

What are the most severe complications of thoracentesis?

Answer 53

Tension pneumothorax and hemothorax are the most severe complications, but the complication rate is kept low with proper procedure and ultrasound guidance.

Question 54

When is the use of small-bore pleural drains (pigtail catheters) appropriate?

Answer 54

Pigtail catheters are effective and safe for most pleural effusions except for hemothorax and thick empyema.

Question 55

What factors affect the success rate of pleural effusion drainage?