What is thoracentesis?
Thoracentesis is a medical practice used for the diagnosis and treatment of pleural diseases. In particular, thoracentesis is reserved for pathologies such as hypertensive pneumothorax and pleural effusion, in which there is, respectively, the accumulation of air and fluid inside the pleural cavity.
Thoracentesis is an invasive procedure, practiced under local anesthesia: the specialist, after introducing a needle or a cannula directly into the patient's chest, sucks in excess fluid or air accumulated there.
Indications and contraindications
PLEURIC SPILLAGE
In the context of a pleural effusion, diagnosed by a chest X-ray, it is possible to proceed with thoracentesis to withdraw the fluid accumulated in the pleural space. The sample thus collected is subsequently sent to the analysis laboratory, where the nature of the etiopathological agent involved in the pleural disease will be identified.
Diagnostic thoracentesis can be performed before a new episode of pleural effusion in the absence of an apparent cause, after having ascertained the abnormal accumulation of pleural fluid by ultrasound of the chest.
The same medical procedure can also be considered for therapeutic purposes: the excess fluid - accumulated between the two serous sheets that make up the pleura - can be completely removed by thoracentesis. In this sense, the evacuation of pleural fluid relieves breathing difficulties and chest pain perceived by the patient suffering from pleural effusion.
PNEUMOTORACE
The same goes for pneumothorax: thoracentesis is particularly suitable for treating the hypertensive (or valve) variant of pneumothorax. Removing the air accumulated in the pleural cavity promotes thoracic expansion, facilitating breathing.
Thoracentesis to treat hypertensive pneumothorax should only be performed by physicians experienced in the field, as the procedure can be dangerous.
Pleural effusion persistent for more than three days
Pleural effusion and severe dyspnea
Large pleural effusion (procedure not always possible)
Pleural effusion with suspected infection
Suspected presence of blood in the pleural cavity
Tension pneumothorax (procedure not always possible)
Coagulation disorders
Pulmonary emphysema (also previous history)
Severe cardiopulmonary impairment
Pleural adherence ascertained
Chest wall infections at the injection site
rupture of the diaphragm
Patient who does not cooperate
In some particularly serious clinical conditions, such as hemothorax, tension pneumothorax and large pleural effusion, the patient runs the risk of suffering severe cardiopulmonary compromise. In such circumstances, where the accumulation of air or fluid severely affects the function of the heart and lungs, it is advisable to have the patient undergo a thoracotomy (open drainage of the pleural cavity).
Execution of the intervention
Before proceeding with the diagnostic / evacuative therapy, the patient must sign a form in which he declares to have been informed about the aims, methods and risks of the intervention, giving his consent to the execution of the thoracentesis. As mentioned, before the procedure it is suggested to perform an X-ray or an "ultrasound of the chest.
It is strongly recommended to inform the doctor in case of allergy to certain medications, such as lidocaine, NSAIDs, acetylsalicylic acid, etc. The possible intake of medicines capable of altering blood clotting, such as coumadin, sintrom and aspirin itself.
After having performed all the necessary tests, you can proceed with the thoracentesis. The patient, after wearing a gown, is invited to sit on a bed or table, leaning forward and resting his elbows on a solid surface. The doctor uses a stethoscope to roughly understand the degree of respiratory compromise.
After this procedure, an antiseptic solution (containing iodine or chlorhexidine) is applied to the patient's chest, directly where the thoracentesis will be performed. At this point an anesthetic liquid will be injected.
Subsequently, he introduces the needle of an empty syringe on the mid-scapular line or on the posterior axillary line, until the pleural cavity is reached. For the removal of air from the tension pneumothorax, the second intercostal space on the mid-clavicular line is considered. As the needle is introduced into the thoracic cavity, another anesthetic is injected. During this phase the patient may feel pressure, exerted precisely by the penetration of the needle through the tissues.
The aspiration of excess pleural fluid must be performed with extreme care, intermittently.
For evacuative (therapeutic) thoracentesis it is necessary to proceed with the insertion of a drainage catheter, which must advance into the pleural cavity under continuous aspiration. In this phase, the doctor can ask the patient to speak or sing: in doing so, it minimizes the risk of lung expansion, which would come into contact with the needle.
The evacuation of pleural fluid usually takes 15 minutes: patients often complain of discomfort during thoracentesis and mild chest pain following the procedure.
Upon completion of the fluid removal, a back bandage is performed.
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Useful tips and advice
Precautions- An uncooperative patient will need to be mildly sedated to avoid complications during the procedure
- The localization of the pleural effusion must be confirmed with techniques of imaging
- CT or ultrasound makes it possible to identify more clearly the angle of introduction of the needle
- To facilitate thoracentesis, the patient should assume a sitting position, with the head raised 30-45 degrees. In this way, a posterolateral approach is favored.
- The entire diagnostic / therapeutic procedure must be performed under antiseptic conditions
- The amount of liquid aspirated should not exceed one liter to escape the risk of developing pulmonary edema.
In mechanically ventilated patients, it is recommended to conclude with an additional chest x-ray after thoracentesis to ensure that fluid has been completely evacuated.
Thoracentesis: Results, Risks, Complications "
