Page 609 - Clinical Hematology_ Theory _ Procedures ( PDFDrive )

CHAPTER 29 ■ Body Fluid Analysis 593

BOX 29.1

Clinical Correlations (Pleural Fluid)

TRANSUDATES

Congestive heart ailure

Cirrhosis with ascites

EXUDATES

In ectious diseases

Empyema

uberculosis

Malignant neoplasms

Lymphoma

Mesothelioma

Pancreatitis

Rheumatoid arthritis

Laboratory Analysis

Physical Characteristics

ransudates are usually clear, are pale yellow, and do not

clot. In comparison, exudates can display a range o colors

depending on the associated disorder ( able 29.6). Only

2 mL o circulating blood in 1 L o pleural f uid will pro-

duce a blood-tinged appearance. Very viscous f uids, clear

or bloody, are characteristic o mesothelioma. In addition,

exudates may be cloudy or purulent and requently clot on

standing because o the presence o brinogen.

Specimen turbidity may be caused by lipids or result rom
FIGURE 29.5 A. A substantial amount o pleural f uid has accu-

mulated in this patient’s right chest cavity (arrow). B. A er draining an increased number o leukocytes. A clear supernatant a er
o more than 100 mL o f uid, the patient’s chest radiograph reveals centri ugation indicates the presence o an abundant number

a decreased amount o f uid in the right chest cavity. o leukocytes, but a white supernatant is caused by chylomi-
crons. In contrast, chyli orm or pseudochylous pleural e usions

resemble a chylous e ect. T ese e usions have a milky or green-
Pleural Effusion
ish appearance and might have a pearly opalescent sheen. T is

T e accumulation o f uid in the pleural space is re erred to appearance results rom cellular debris and cholesterol crystals.

as a pleural effusion. Excess f uid accumulates i the balance

o f uid ormation and absorption is in disequilibrium. T is

may be caused by an increased production or a decreased TABLE 29.6 Representative Exudate

absorption o f uid. Large quantities may need to be drained. Appearance

Aspiration o pleural f uid is re erred to as thoracentesis Typical Associated

(Fig. 29.5). Failure to remove an increased accumulation o Appearance Disorder

leukocytes or blood rom the pleural space may lead to the

ormation o brothorax and a subsequent impairment o Dark red-brown Amebiasis

pulmonary unction. Greenish to greenish Classic rheumatoid effusion

Te location o a pleural e usion may be suggestive yellow and turbid

o the type o disorder involved in causing the e usion

(Box 29.1). ypically, le -sided e usions are associated Yellow and turbid Infectious process

with conditions such as a ruptured esophagus or acute Milky Chylothorax (chylous or

pancreatitis. pseudochylous)

I a f uid has the general characteristics o an exudate, Bloody (hemorrhagic) Traumatic tap, malignancy,

at a minimum, a Gram’s stain and culture and cytological pulmonary infarction, trauma,

studies need to be per ormed. An open lung biopsy o tissue pancreatitis, tuberculosis

or examination with histochemical stains and electron Clearly visible pus (WBCs) Empyema

microscopy may be required or a diagnosis in suspected

malignant conditions. Foul odor Anaerobic bacterial infection