The pleural puncture (synonym: thoracentesis ) is a special puncture in medicine . Which is usually done by a local anesthetic, a sterile needle into the pleural cavity , the gap space between the pleura and pleura inserted.
The method can only be carried out if there is enough fluid in the pleural space. It is used for diagnostic reasons (obtaining test material, for example in the case of an unclear cause of a pleural effusion and in patients with pneumonia and pleural effusion to exclude pleural empyema ) or for therapeutic reasons (relief of a larger pleural effusion, particularly in the case of respiratory, breathing (acute shortness of breath ), or cardiac, heart- related, decompensation ).
If heart failure is probable with a pleural effusion , the guideline-based treatment is the focus and a pleural puncture is not indicated.
The method should be used under ultrasound guidance in order to mark the exact location of the effusion before the puncture or to position the puncture needle safely under this thoracic sonography, in particular to avoid a (post-puncture) pneumothorax, which occurs in 0.6 to 6% of cases . A current chest X-ray should be available prior to the puncture. The patient sits with his back to the doctor. A local anesthetic should be injected into the skin and pleura prior to the puncture . The aseptic technique is used to puncture just above the upper edge of a rib in order to avoid damaging the nerves and lymph and blood vessels that run along the lower edge.
The sample volume of a diagnostic pleural puncture is approximately 50 ml, the use of a three-way stopcock is recommended. A bilateral puncture is only performed in an emergency. Usually no more than 1000–1200 ml (in adults a maximum of 1500 ml) is taken during a puncture, as otherwise reactive pulmonary edema can arise as a reaction to the changed pressure and volume conditions.
The thoracentesis, which in the Middle Ages to the relief of a hemothorax was known ( Wolfram von Eschenbach describes in Parsifal , is a thoracentesis), in the hands of an experienced physician, a simple and quick method for example with extensive bruising and dyspnea (shortness of breath) the To provide relief for those affected.
After about two hours, an X-ray check can be made to rule out a lung injury , but is not necessary if there are no symptoms. The punctured patient should always be observed for one to four hours, since most pleural injuries after a puncture become noticeable during this period.
Possible complications of the method
- Infection (low risk with sterile needle and good skin disinfection)
- Injury to the lungs with possible pneumothorax
- rarely with a large effusion
- more often with chambered effusion or puncture while lying down (in up to 6% of pleural functions)
- Injury to the liver or spleen
- Post-bleeding (if possible, the blood's ability to clot is checked before the puncture. The INR value should be less than 1.5)
- reactive pulmonary edema
- Adhesions and chambers of an effusion, almost regular with repeated punctures, which make it difficult to empty again.
Investigation of the puncture
The pleural fluid obtained is first examined with the naked eye (macroscopically). If it has a milky appearance, this indicates the presence of lymph in a chylothorax (accumulation of lymph fluid in the chest). If pus can be seen, there is a pleural empyema (centrifuging the fluid enables a more precise differentiation between chylothorax and pleural empyema: the chylous fluid remains milky, while empyema produces a clear supernatant). In the case of a bloody effusion, if there is no bleeding caused by the puncture, the suspicion of a malignant tumor disease. In the case of a diagnostic pleural puncture, the concentrations of lactate dehydrogenase (LDH) and proteins in the liquid obtained are usually determined in order to be able to differentiate between transudate and exudate in comparison with the corresponding measurement results in the blood serum and thus to enable a narrow assignment to various causes (for this serve the light criteria ). In addition, the sample is examined microscopically using Gram staining , a blood culture is created to detect pathogens, if necessary supplemented by a polymerase chain reaction (using the 16S rRNA gene), and a differential blood count is created and a cytological assessment is carried out . If necessary, the pH value (in the case of non-purulent pleural fluid and suspected infection), the concentration of glucose normally corresponding to the blood (decreased for example in rheumatoid arthritis, empyema, tuberculosis or malignant cause), the increased blood lipids triglycerides and in chylothorax (which also increases with exudate) cholesterol and amylase (indicator of acute pancreatitis when the concentration is increased ). If tuberculous pleurisy is suspected, the examination for acid-resistant rods, a special blood culture and a polymerase chain reaction are carried out. The reduced hematocrit value in anemia should be determined if a hemothorax is suspected.
- Martin Leuwer, Oliver Zuzan, Hans-Joachim Trappe, Gernot Marx: Checklist for Interdisciplinary Intensive Care Medicine . Georg Thieme Verlag, August 2009, ISBN 978-3-13-116913-6 , pp. 67-68.
- Berthold Jany, Tobias Welte: Pleural effusion in adults - causes, diagnosis and therapy. In: Deutsches Ärzteblatt. Volume 116, No. 21, (May) 2019, pp. 377-385.
- S. Ewig, G. Höffken, WV Ker u. a .: S3 guideline treatment of adult patients with outpatient pneumonia and prevention - update 2016. In: Pneumologie. Volume 70, 2016, pp. 151-200.
- Berthold Jany, Tobias Welte: Pleural effusion in adults - causes, diagnosis and therapy. In: Deutsches Ärzteblatt. Volume 116, No. 21, (May) 2019.
- Bernhard Dietrich Haage: The Thorakozentese in Wolframs von Eschenbach 'Parzival' (X, 506, 5-19). In: Würzburg medical history reports. Volume 2, 1984, pp. 79-99.
- J. Schnell, M. Beer, S. Eggeling u. a .: S3 guideline: Diagnosis and therapy of spontaneous pneumothorax and post-interventional pneumothorax. In: Zentralblatt für Chirurgie. Volume 143, 2018, pp. 12-43.
- Increase in neutrophil granulocytes often in acute processes such as effusion in pneumonia, in empyema or as a result of a pulmonary embolism. Lymphocytes predominate in tuberculosis, long-standing pleural effusions, heart failure, or a malignant cause.
- A low pH ( acidosis ) of the pleural fluid can indicate a complicated infection of the pleura, tuberculosis, rheumatoid arthritis and malignant effusions. If the pH value is below 7.2, a pleural drainage should be applied as soon as possible . See: Berthold Jany, Tobias Welte: Pleural effusion in adults - causes, diagnosis and therapy. 2019, p. 382 f.