plevral efüzyon

 

Plevral Efüzyon

Although pleural effusion has a wide array of etiologies, large series have shown that cancer, heart failure, and parapneumonic infections account for most cases

We inquire about any heart, liver, or renal disease that may predispose patients to a pleural effusion due to fluid overload. We also inquire about lung conditions that may predispose a patient to parapneumonic effusion or malignant pleural effusion (eg, chronic bronchitis, bronchiectasis, immune deficiency).

The patient may have a known disorder that may raise the suspicion for other less common causes of a pleural effusion including systemic lupus erythematosus (pleuritic exudate), hypothyroidism (transudative pleural effusion), amyloidosis (exudative pleural effusion), pancreatitis (amylase-rich pleural effusion), lymphangioleiomyomatosis (chylous effusion), rheumatoid arthritis (cholesterol effusion), and immunoglobulin G4 (pleuritic exudate)

Drug and occupational history – A careful drug history may reveal that the patient is taking nitrofurantoin, amiodarone, ovarian stimulation therapy, or a drug that can produce a lupus-like syndrome (eg, hydralazine)

Patients may also be taking immunotherapy and have immunotherapy-related pleural effusion

Potential extra-pleural sources – Pleural fluid may originate from extrapleural sources, most commonly from transdiaphragmatic movement. A detailed history and examination for ascites (hepatic hydrothorax) and urinary tract obstruction (urinothorax) are important. Patients receiving peritoneal dialysis (PD) are at risk of developing a PD-related pleural effusion

While chest computed tomography (CT) is not necessary in every case of pleural effusion, it is useful in the following scenarios :

●When the etiology is not obvious

●When the pleural effusion appears complex and loculated

●When malignancy or other diseases more apparent on CT are suspected (eg, lymphangioleiomyomatosis [LAM])

Irregular or thickened pleura with contrast enhancement suggests pleural inflammation or malignancy and identifies optimal sites for CT-guided needle aspiration or cutting needle biopsy.

Torasentez

Indications — Thoracentesis may be diagnostic and/or therapeutic:

●Diagnostic (new effusion of unclear etiology) – Most patients who have a newly detected pleural effusion of unclear etiology should undergo diagnostic thoracentesis to determine the nature of the pleural effusion (ie, transudate, exudate) and to identify potential causes.

The exceptions are when there is only a small amount of pleural fluid with a secure clinical diagnosis (eg, pneumonia) or when there is clinically obvious congestive heart failure (CHF) with typical features (eg, bilateral pleural effusions and pulmonary edema) .

In a patient with suspected CHF, atypical features that should prompt consideration of diagnostic thoracentesis include the following:

•Features that suggest an alternate etiology for the effusion (eg, unilateral or bilateral effusions of significantly disparate sizes, especially if the effusion on the left is larger than on the right)

•Plörezi ya da ateş semptomları

•Kanser ya da enfeksiyon bulguları

•Kalp yetmezliği ile uyumsuz EKO

•A disproportionately wide alveolar-arterial oxygen gradient

•Efektif tedaviye rağmen çözülmeyen KY bulguları

Kalp yetmezliğinde (diğer efüzyon sebeplerinde göre )semptom ve bulgular daha belirgindir. Plöritik ağrı nadirdir.

Kalp yetmezliği olan hastaların 2/3’ünde efüzyon vardır, %50’sinde bilateraldir ve

genellikle sağ taraflıdır

Transuda-Eksüda 

 

 

in patients with cardiac failure receiving diuretic therapy, the transudative pleural fluid may have an elevated protein level and be mistakenly classified as an exudate. Calculating a serum-to-pleural fluid gradient for albumin or protein may reclassify the effusion as a transudate.

In patients with borderline or discrepant results, we also consider the possibility that the pleural effusion has more than one cause

Add condition-specific biomarkers, when indicated

When heart failure is suspected but the pleural fluid is borderline exudative, some experts measure the total protein or albumin gradient.

Similarly, if a cholesterol or chylous effusion is suspected, we obtain pleural fluid triglycerides and cholesterol levels and consider definitive tests such as chylomicrons (chylous effusion) and microscopic examination for cholesterol crystals (cholesterol effusion).

In patients with a lymphocytic effusion, further investigation should be considered for TB (eg, adenosine deaminase), lymphoma (cytometry, flow cytometry), chylothorax (triglycerides), and pseudochylothorax (cholesterol) 

 

Plevral sıvı analizi

Routine pleural fluid biomarkers — For every patient with a pleural effusion, we routinely perform all of the following tests on initial pleural fluid samples:

●Cell counts and cell differential

●Total protein

●Lactate dehydrogenase (LDH)

●Glucose

●Cholesterol

Some experts also perform pleural fluid culture, Gram stain, and cytology, especially when pleural infection or malignancy appear possible diagnoses.

Suspected heart failure-related pleural effusion 

CHF-related pleural effusions are typically transudative . However, 25 to 30 percent of patients with CHF have their pleural effusion misclassified as exudative by combination test criteria, such as Light's criteria . This misclassification is thought to be due to performance of thoracentesis after initial diuresis, elevated erythrocytes in the pleural space (the latter increases the LDH level), and/or inherent limitations of approaches to classifying pleural effusions . In such cases, we measure the following:

●Albumin or total protein gradient – Calculation of the serum-to-pleural fluid albumin or protein gradient may help distinguish a transudate from an exudate.

Suspected tuberculous pleural effusion — When tuberculous (TB) pleural effusion is suspected (eg, patient with a pleural effusion who lives in an endemic region for TB), we obtain pleural fluid acid fast bacillus (AFB) smear and TB cultures as well as adenosine deaminase (ADA).

AFB smear and TB culture – AFB and TB culture should always be performed since a positive culture is diagnostic. However, AFB and culture results are only positive in less than 50 percent of patients (higher if the fluid is grossly purulent) and may take up to eight weeks.

●ADA – ADA results can be obtained more quickly than culture results and can therefore facilitate a presumptive diagnosis so that therapy can be promptly initiated, when indicated. Measurement of ADA is particularly helpful in regions with a high prevalence of TB and is most useful when the effusion is lymphocyte-predominant and initial AFB smear and culture are negative

Suspected malignancy — For patients with suspected MPE (eg, patient with tobacco exposure who has a large, new-onset pleural effusion), we perform cytology.

In patients with a high suspicion for mesothelioma, we often proceed directly to biopsy since pleural fluid analysis may have a low yield for the diagnosis of mesothelioma

For patients with suspected lymphoma or multiple myeloma, we also obtain flow cytometry and immunohistochemical staining, which, if positive, may help support the diagnosis

Suspected pancreatic- or esophageal rupture-related effusion — When pancreatic-related pleural effusion is suspected, we obtain pleural fluid pancreatic amylase (eg, chronic pancreatitis and a right-sided pleural effusion). When esophageal rupture is suspected, we obtain salivary amylase and pleural fluid pH (eg, patient with recurrent or violent vomiting and a pleural effusion).

Suspected chylous or cholesterol effusion — A cholesterol pleural effusion may be suspected in a patient with risk factors (eg, chronic TB or rheumatoid pleuritis, milky fluid on gross appearance ) while chylothorax may be suspected in patients with a separate group of risk factors (eg, trauma, malignant tumors of the mediastinum, lymphangioleiomyomatosis, milky fluid on gross appearance ). In both scenarios, we typically obtain cholesterol and triglyceride levels.

INTERPRETING PLEURAL FLUID FINDINGS

Gross appearance 

●Turbid (bulanık ) fluid – Draw a pH and perform microbiologic testing

●Milky fluid – Assay for lipids and cholesterol

●Bloody fluid – Obtain a hematocrit ("pleurocrit") and cytology

●Black fluid – Perform fungal and bacterial cultures, amylase, cytology, and hematocrit

●Green fluid – bilirubin, cytology, and rheumatoid factor

Transudates – Transudates result from imbalances in hydrostatic and oncotic pressures in the chest in patients with congestive heart failure (CHF), liver failure, and nephrosis. They can also be due to conditions external to the pleural space (eg, peritoneal, cerebrospinal fluid) or to iatrogenic conditions (eg, crystalloid infusion through a central venous catheter that has migrated into the mediastinum or pleural space).

Exudates – In contrast, exudative effusions present more of a diagnostic challenge. Disease in virtually any organ can cause exudative pleural effusions by a variety of mechanisms, including infection, malignancy, immunologic responses, lymphatic abnormalities, noninfectious inflammation, iatrogenic causes, and movement of fluid from below the diaphragm (eg, acute or chronic pancreatitis, chylous ascites, and peritoneal carcinomatosis) .

Exudates result primarily from pleural and lung inflammation (resulting in increased entry of fluid and protein due to elevated capillary permeability), impaired lymphatic drainage of the pleural space (resulting in a decreased removal of pleural fluid and protein), or movement of fluid from the peritoneal space.

Ayrım için kullanılan kriterler:

Pleural fluid only three-test combination (PFO3) — We use PFO₃, a three-test combination approach , as our preferred calculation . A pleural effusion is considered an exudate if any one or more of the following are present:

●Pleural fluid protein greater than 3.0 g/dL (30 g/L)

●Pleural fluid cholesterol greater than 55 mg/dL (1.424 mmol/L)

●Pleural fluid LDH greater than 0.67 times the upper limit of the laboratory's normal serum LDH

Light's criteria (three-test combination rule) — The Light's Criteria Rule is a commonly used three-test rule that measures serum and pleural fluid protein and LDH .

According to the Light's Criteria Rule, if at least one of the following three criteria (ie, component tests of the rule) is fulfilled, the fluid is defined as an exudate :

●Pleural fluid-to-serum protein ratio greater than 0.5

●Pleural fluid-to-serum LDH ratio greater than 0.6

●Pleural fluid LDH greater than 0.67 (ie, two-thirds) the upper limits of the laboratory's normal serum LDH

For patients with suspected heart failure who have an atypical presentation and whose pleural effusion is suspected to be misclassified as an exudate, we use either one of the following single-test criteria to help recategorize the pleural effusion as a transudate :

•Serum-to-pleural fluid albumin gradient (ie, the difference between the serum and pleural values) greater than 1.2 g/dL (12 g/L)

•Serum-to-pleural fluid protein gradient greater than 2.5 g/dL (25 g/L)