Author(s): Sandeep Hothi and David Sprigings
Indications, contraindications and potential complications are summarized in Table 120.1.
Imaging with echocardiography is recommended to guide pericardiocentesis, and can be used in one of three ways: imaging before advancement of the needle, to establish the anatomy; imaging before and intermittently during advancement of the needle; continuous imaging throughout the procedure. Unless pericardiocentesis is required in the setting of actual or incipient cardiac arrest, the procedure should be done in a cardiac catheterization room with immediate access to X-ray screening (fluoroscopy) if needed.
Equipment needed is given in Table 120.2. You will need at least two assistants, to monitor the patient during the procedure and assist with the equipment.
Technique
Preparation
- Confirm the indication for the procedure. Check for contraindications, though these are relative if there is cardiac tamponade. Obtain the informed consent of the patient. Blood should be sent for group and screen. Ensure that a defibrillator and other resuscitation equipment is to hand.
- The patient should be sitting up at 30–45 degrees, so that the pericardial effusion pools anteriorly and inferiorly. The main approach is subcostal (Figure 120.1). Choose the approach with the largest thickness of effusion (this should be 2cm or greater), and decide on the optimum needle trajectory, avoiding the liver or lung. Measure the depth from the skin surface to the pericardial effusion and mark the planned puncture site with an indelible marker.
- Connect an ECG monitor and put in a peripheral venous cannula. Give supplemental oxygen via nasal cannulae or mask, with continuous monitoring of oxygen saturation by oximetry. If sedation is required, midazolam may be considered, balanced against the risks of respiratory depression. Give 2 mg (1 mg in elderly) IV over 30s, followed after 2 min by 0.5–1 mg increments if sedation is not adequate (usual range 2.5–5 mg).
- Put on hat, mask, sterile gown and gloves. Prepare the skin from mid-chest to mid-abdomen with chlorhexidine or povidone-iodine and apply drapes to a wide area.
Pericardiocentesis
- Anaesthetize the skin at the planned puncture site with a 25 G (orange) needle, and then use a 21 G (green) needle to infiltrate local anaesthetic along the intended needle track towards the effusion. With the left parasternal approach, a green needle is usually long enough to enter the effusion. Allow the local anaesthetic time to work and then make a small skin incision with a scalpel at the puncture site.
Advance the needle into the pericardial space.
Subcostal approach: attach the long needle to a 10 mL syringe containing lidocaine 1% and introduce 1cm below the left xiphocostal angle. Then advance slowly at an angle of 30° to the skin, along the anesthetized track, aiming for the left shoulder, with continuous aspiration and intermittent injection of lidocaine.
Other approaches are possible and are described below, but should only be used by cardiologists / cardiac surgeons with appropriate training.
Left parasternal approach: the needle is attached to a 10 mL syringe containing lidocaine and inserted at 90° to the skin over the superior margins of the fifth or sixth rib adjacent to and within 1cm, or 3–5cm lateral to, the left sternal margin (avoiding the LIMA).
Apical approach: insert the needle over the superior rib margins in the fifth to seventh left interspace over the cardiac apex.
- When you aspirate pericardial fluid, advance the needle a couple of mm further, then remove the syringe and introduce about 20cm of the guidewire (J end leading). See section on Troubleshooting below if you are not sure whether the fluid is haemorrhagic pericardial effusion or blood.
- Pass the dilator over the guidewire to dilate the subcutaneous track and pericardium (taking care not to advance it further into the effusion) and then remove the dilator.
- Put the pigtail catheter on the guidewire and advance it over the guidewire and into the pericardial space, so that around 20cm of the catheter is within the pericardium. It helps to keep the guidewire fairly taut.
- Remove the guidewire and aspirate 50 mL or more via the catheter. Take specimens for microscopy, culture and cytology. Attach the connector and drainage bag to the catheter via a three-way tap. If the indication for pericardiocentesis was cardiac tamponade, aspirate as much fluid as possible.
- Insert a skin suture and loop it over the catheter several times, tying it each time, or use a device to anchor and support the catheter as it exits the skin.
Final points
- Dispose of sharps safely. Arrange a chest X-ray to exclude pneumothorax. Check with echocardiography the size of the residual effusion.
- Document the procedure in the patient's record, including: indications/approach/appearance of pericardial fluid/samples sent/any complications/post-procedure chest X-ray findings/post-procedure echocardiographic findings/management plan.
Aftercare
- Leave the catheter on free drainage. Analgesia may be needed to relieve pericardial pain. Remove the catheter within 72h to prevent infection.
- Further management depends on the aetiology of the effusion.
Troubleshooting
You cannot enter the effusion
- Check that the diagnosis is correct and that the effusion does not look solid or loculated.
- Consider using an alternative approach, provided the effusion is >2cm thickness.
The pigtail catheter will not pass over the guidewire into the pericardial space- Check that the guidewire is correctly positioned within the cardiac shadow (use fluoroscopy to image the guidewire).
- Check that the guidewire is held taut and not looped.
- Repeat the dilatation of the subcutaneous track.
You aspirate heavily bloodstained fluid- The possibilities are: haemorrhagic effusion (common in malignancy or Dressler syndrome); venous puncture; right heart puncture; or laceration of a coronary artery with haemopericardium.
- Keep hold of the needle, but remove the syringe and empty it into a clean pot. Blood will clot, but even heavily bloodstained effusion will not.
- Inject 10 mL of an agitated 9.5 mL 0.9% saline/0.5 mL solution (rapidly mixed using a three-way tap to create microbubbles) through the exploring needle to determine the space within which the needle tip resides under echocardiographic imaging.
- If you are still in doubt, compare the haematocrit of the fluid with that of a venous sample (both sent in ethylene diaminetetra-acetic acid (EDTA) tubes), or connect to a pressure monitor: right ventricular penetration is shown by a characteristic waveform.