thoracocentesis-141

Medical

1. by Dr. Saitejreddy

2. Thoracentesisis a percutaneousprocedure during which a needle is
inserted into the pleural space and pleural fluid is removed either through
the needle or a small bore catheter.
"Diagnostic thoracentesis" refers to removal of a small volume of pleural
fluid for analysis, while "therapeutic thoracentesis" refers to removal of a
large volume of pleural fluid for relief of symptoms.

3. INDICATIONS
1.Pleural effusion-Most patients who have a pleural effusion should
undergo diagnostic thoracentesisto determine the nature of the effusion
(ie, transudate, exudate) and to identify potential causes (eg, malignancy,
infection).
2. Atypical features that should prompt consideration of diagnostic
thoracentesisin a patient with HFinclude:
•Bilateral effusions that are of markedly disparate sizes
•Pleurisy
•Fever
•Absence of cardiomegalyon chest radiograph
•An echocardiogram that is inconsistent with HF
•B-type brain natriureticpeptide (BNP) levels that are inconsistent with HF
•An alveolar-arterial oxygen gradient that is larger than expected for HF
•The effusion does not resolve with HF therapy

4. CONTRAINDICATIONS—There are no absolute contraindications to
thoracentesis.
1.Anticoagulation or a bleeding diathesis, with a PT or PTT greater than
twice the midpoint of the normal range, a platelet count less than 50,000
platelets/mm
3
, or a serum creatinineconcentration greater than 6
mg/dL.
2.very small free-flowing pleural effusions, with less than 1 cm distance
from the pleural fluid line to the chest wall on a decubituschest
radiograph.
3.Patients receiving mechanical ventilation with or without positive end-
expiratory pressure (PEEP)
4.Active skin infection at the point of needle insertion.

5. •TECHNIQUE
Once the procedure has been explained to the patient and
informed consent obtained, the patient is positioned for the
procedure. Thoracentesisis usually performed with the
patient in a sitting position, sitting upright with his or her
arms resting on a surface, such as a bedside table. The lateral
recumbent position can be used if the patient is unable to sit
upright.

6. Selection of site-
Ultrasound localization is performed with the patient in the same
position that he or she will be in during the thoracentesis, especially
if it is being used for a loculatedeffusion
By the physical examination to select the puncture site, using the
following landmarks-
•One to two interspaces below the level at which breath sounds
decrease or disappear on auscultation, percussion becomes dull,
and fremitusdisappears
•Above the ninth rib, to avoid subdiaphragmaticpuncture
•Midway between the spine and the posterior axillaryline, because
the ribs are easily palpated in this location.

7. •Avoidance of intercostalarteries—when performing a
thoracentesison an elderly patient, it is prudent to choose a
puncture site 9 to 10 cm lateral to the spine, assuming that
the fluid collection will be equally accessible.
•Site preparation and local anesthesia—Thoracentesisis a
sterile procedure. A wide area surrounding the puncture site
should be sterilized with 0.05 percent chlorhexidineor 10
percent povidone-iodine solution, prior to placement of
sterile drapes around the puncture site.
•Once the puncture site and surrounding skin is sterilized, local
anesthetic (eg, 1 or 2 percent lidocaine) should be
administered. The epidermis is initially infiltrated with
anesthetic using a syringe and 25-gauge needle. Next, a
syringe with a 22-gauge needle is inserted, advanced toward
the rib, and then "walked" over the superior edge of the rib.

8. •As the needle is advanced, aspiration should be attempted by
intermittently pulling back on the plunger of the syringe.
Anesthetic is injected if there is no return of blood or pleural
fluid into the syringe.
•Intermittent aspiration serves two purposes. First, blood
return indicates that the needle is intravascular and prevents
the operator from injecting anesthetic intravascularly. Second,
pleural fluid return indicates that the needle has entered the
pleural space.

9. •Additional anesthetic should be injected to anesthetize
pleural nerve endings and then the needle should be
withdrawn. This technique infiltrates the skin, rib periosteum,
and parietal pleura with local anesthetic, thereby minimizing
pain and rendering the discomfort of the procedure similar to
that of venipuncture.
•Fluid removal—A 50 mLsyringe is attached to a 22-gauge
needle that is 1.5 inches in length. A longer needle is selected
for markedly obese patients. Adding 1 mLof 1:1000 heparin
to the 50 mLsyringe prevents clotting of hemorrhagic or
highly proteinaceousfluid and improves the quality of the
cytologicexamination of the pleural fluid. With continuous
negative pressure applied to the syringe by gently pulling back
on the plunger, the needle is advanced through the
anesthetized tract until pleural fluid returns. Approximately 30
to 75 mLof pleural fluid should be withdrawn for analysis, and
then the needle removed.

11. •Aspiration of air implies that the lung has been punctured
because the needle was inserted superior to the effusion or
too deeply. Aspiration of a small amount of blood suggests
that the needle may have been inserted inferior to the
effusion (ie, subdiaphragmatically). Failure to aspirate
anything implies that the needle may have been too short to
penetrate the pleura, especially in an obese patient.
•Common tests performed on pleural fluid include cell count,
pH, protein, lactate dehydrogenase, glucose, amylase, gram
stain, culture, and cytology.
•FOLLOW UP-
A chest radiograph is indicated if air was aspirated during the
procedure, symptoms or signs of pneumothoraxdevelop, or
multiple needle passes were required.

12. •COMPLICATIONS—Potential complications of thoracentesis
include pain at the puncture site, bleeding (eg, hematoma,
hemothorax, or hemoperitoneum), pneumothorax, empyema,
soft tissue infection, spleen or liver puncture, vasovagal
events, seeding the needle tract with tumor, and adverse
reactions to the anesthetic or topical antiseptic solutions.
Pneumothoraxis the most common complication that is
clinically important.
When a pneumothoraxoccurs, it is usually small although up
to one third of patients require tube thoracostomydrainage.
Tube thoracostomyshould be considered if the
pneumothoraxis large, progressive, the patient is
symptomatic, or the patient is mechanically ventilated.

13. Thank You