Pericardiocentesis

Anatomy and Physiology

Anatomy

The pericardium is a double-layered sac surrounding the heart, consisting of the fibrous outer and serous inner pericardium, further divided into the visceral and parietal layers. The visceral pericardium, composed of mesothelial cells, adheres to the cardiac epicardium, while the parietal pericardium is a fibrous structure, primarily collagenous, with a thickness of less than 2 mm. Between these layers lies the pericardial cavity, a potential space containing 15 to 50 mL of serous fluid, which reduces friction during cardiac movements. This fluid, essentially filtered plasma, is primarily distributed over the interventricular and atrioventricular grooves and drains into nearby lymph nodes.[4] Key anatomical landmarks for pericardiocentesis include the left costoxiphoid angle, the subxiphoid area, and the parasternal regions. The proximity of vital structures such as the lungs, coronary arteries, and phrenic nerve—which innervates the pericardium—underscores the importance of precise anatomical knowledge to minimize complications. A pericardial effusion represents an abnormal increase in pericardial fluid volume, which may necessitate therapeutic intervention. 

Physiology

The pericardium provides mechanical protection for the heart, prevents excessive dilation during volume overload, ensures optimal cardiac positioning within the thorax, and facilitates smooth cardiac motion through lubrication. Under normal conditions, the pericardial sac contains up to 50 mL of fluid, enabling unhindered cardiac cycles. However, when fluid accumulates excessively, the pericardium’s nonelastic nature limits its ability to stretch, increasing intrapericardial pressure. The rate of fluid accumulation determines the pericardium's capacity to adapt. Slow accumulation, as seen in chronic conditions like malignancy, allows the pericardium to stretch and accommodate volumes of up to 2 liters without immediate decompensation. In such cases, the pressure-volume curve of the pericardium shifts to the right, reflecting gradual dilation.

Conversely, during rapid fluid accumulation, as seen with trauma or ventricular wall rupture, the pericardium can hold 80 to 200 mL of fluid acutely before its adaptive capacity is overwhelmed. This sudden increase in intrapericardial pressure quickly leads to physiologic decompensation. When the pericardial volume expands beyond the compliant range, regardless of the accumulation rate, intrapericardial pressure rises sharply, leading to tamponade and hemodynamic compromise.[4]

Pathophysiology

Pericardial effusion results from an imbalance between fluid production and drainage, leading to excessive accumulation within the pericardial cavity. Causes include infections, malignancies, autoimmune diseases, trauma, metabolic disorders such as uremia, and iatrogenic factors like radiation or chemotherapy. The clinical impact of an effusion depends on its volume, accumulation rate, and pericardium compliance. Even in small volumes, rapid fluid accumulation can result in cardiac tamponade. In this life-threatening condition, increased pericardial pressure impairs diastolic ventricular filling, leading to reduced stroke volume and cardiac output. In contrast, slow accumulation allows for pericardial stretching, often resulting in chronic effusion with less immediate hemodynamic compromise.

In tamponade, increased pericardial fluid compresses the low-pressure right-sided chambers first, limiting their filling. This increases ventricular interdependence, where the volume in 1 chamber rises at the expense of the other. During inspiration, decreased intrathoracic pressure enhances venous return to the right heart, shifting the interventricular septum leftward and impairing left ventricular filling. This exaggerated normal physiology manifests as pulsus paradoxus, characterized by a significant drop in systolic blood pressure (>10 mm Hg) during inspiration due to impaired left ventricular filling. Pericardiocentesis restores normal physiology by relieving intrapericardial pressure, enabling full cardiac expansion and effective hemodynamics. Understanding the anatomical, physiological, and pathophysiological mechanisms of effusion and tamponade is crucial for safely and effectively performing this procedure.

Indications

The common indications for pericardiocentesis include:

• Cardiac tamponade
• Large symptomatic pericardial effusion
• Purulent pericarditis
• Postpericardiotomy syndrome (after cardiac surgery)
• Recurrent effusion
• Traumatic hemopericardium
  • Blunt and penetrating traumatic injuries may cause an accumulation of blood in the pericardial space, termed hemopericardium, leading to cardiac tamponade. Penetrating trauma to the region of the anterior chest delineated superiorly by the clavicles, inferiorly by the costal margin, and laterally by the nipple line, an area known as "the box," from projectiles or sharp-tipped objects has the potential to injure any of the structures in the area and cause cardiac tamponade.[5] 
  • Pericardiocentesis is indicated in patients with blunt or penetrating trauma who are hemodynamically unstable, are in cardiac arrest, or have evidence of pericardial effusion on the focused assessment with sonography for trauma exam and hypotension without another clear etiology.[6] 
  • Posttraumatic pericardiocentesis is usually performed emergently at the bedside as a temporizing measure to stabilize the patient and facilitate transfer to the operating room where definitive treatment, such as the creation of a pericardial window or thoracotomy and surgical pericardiotomy, can be performed.
  • If the pericardiocentesis is unsuccessful, a bedside thoracotomy can be performed to allow for pericardiotomy and drainage of pericardial tamponade.[7]

Contraindications

There are no absolute contraindications to pericardiocentesis in an unstable individual. Removing even a small amount of pericardial fluid in a patient who is unstable with true tamponade can rapidly improve hemodynamics.[8] 

Relative contraindications to pericardiocentesis include:

• Uncorrected coagulopathy
• Low platelet count
• Lack of knowledge about the anatomy of the chest or unclear diagnosis
  • For example, if the pericardial effusion is suspected to be secondary to aortic dissection, accidental puncture of the aorta can lead to catastrophic outcomes.
• Compromised patient cooperation
• Active infection over the access site

Equipment

The following equipment is recommended to perform a pericardiocentesis: 

• Ultrasound machine or fluoroscopy suite
• Continuous hemodynamic and electrocardiographic monitoring [9] 
• Sterile drapes and gloves
• Local anesthetic
• Needles: Long, thin-walled needles (typically 16- to 18-gauge) for accessing the pericardial space
• Catheter: A pigtail catheter, usually sized 6 to 8 Fr
• Guidewire
• Dilators: Plastic dilators of varying sizes to gradually enlarge the tract for catheter insertion
• Syringes: 10 mL or 20 mL syringes for fluid aspiration during the initial needle insertion
• Three-way stopcock
• Extension tubing
• Accessories: Scalpel, collection bag, sutures, and adhesive dressing 

Personnel

A multidisciplinary team is involved in successfully executing a pericardiocentesis procedure to ensure patient safety and optimal outcomes. The performing clinician is typically a qualified cardiologist with expertise in the procedure and thorough knowledge of cardiac anatomy. Imaging guidance, often critical to minimizing complications, may be provided by the performing clinician or a dedicated imaging specialist, such as a radiologist or qualified sonographer.

Nursing staff are vital in patient preparation, intraprocedural monitoring, and post-procedural care. An anesthesiologist or sedation specialist may manage patient comfort and provide sedation or analgesia as needed. Additionally, an emergency surgical backup team must be available to perform a pericardiotomy or pericardial window in case of complications or if the fluid cannot be adequately drained through pericardiocentesis. This coordinated approach ensures procedural safety and effective management of pericardial effusions.[10]

Preparation

Preparation for a pericardiotomy is a structured, multidisciplinary process aimed at ensuring patient safety and procedural efficacy. Key steps include:

• Patient evaluation and clinical assessment
  • Conduct a thorough assessment for clinical signs of cardiac tamponade, visible chest wall deformities, and hemodynamic stability.
  • Arrange respiratory support or oxygen therapy if needed.
• Diagnostic imaging
  • Echocardiography can confirm the pericardial effusion's presence, extent, and location and evaluate its hemodynamic impact.
• Laboratory testing
  • Obtain baseline blood tests, including a complete blood count, coagulation profile, and renal function tests, particularly if sedation or anesthesia is planned.
• Equipment preparation
  • Assemble all necessary equipment, including an ultrasound machine for imaging guidance and monitors for electrocardiogram and hemodynamic monitoring.
• Patient preparation
  • Position the patient in a semirecumbent or supine posture, with the head of the bed elevated 30 to 45 degrees.
  • Administer appropriate analgesia and/or sedation.
  • Prep the insertion site—usually subxiphoid, parasternal, or apical—using sterile techniques and confirm intravenous access.
• Team readiness
  • Ensure a coordinated team is present, including a cardiologist to perform the procedure, an anesthesiologist for sedation, and a cardiac surgeon on standby if surgical intervention is required.
• Postprocedure plan
  • Arrange for fluid analysis if the procedure is diagnostic.
  • Monitor the patient in a high-acuity setting to promptly identify and manage potential complications.

Technique or Treatment

Pericardiocentesis is a procedure used to remove pericardial fluid from the pericardial sac, typically indicated in cases of pericardial effusion with hemodynamic compromise, such as cardiac tamponade. The procedure can be performed using various techniques, typically guided by imaging methods such as echocardiography or fluoroscopy to reduce the risk of complications.  

Echocardiography-Guided Pericardiocentesis  

Echocardiography-guided pericardiocentesis is now the standard of care, offering advantages such as low cost, no radiation exposure, and the ability to perform bedside procedures (see Video. Echocardiography-Guided Pericardiocentesis).[11] The procedure involves identifying the optimal point of entry that avoids vital structures such as the coronary arteries, lungs, and diaphragm.[12] The main approaches include:

• Subxiphoid (subcostal) 
  • This is the most common technique, where the needle is inserted below the xiphoid process, directed toward the left shoulder. This approach provides access to the anterior part of the pericardium and is favored for its safety profile.
• Apical
  • The needle is inserted through the fifth or sixth intercostal space at the left midclavicular line, offering access to fluid near the apex of the heart; this procedure is particularly useful when fluid is localized in that area.
• Parasternal
  • This approach is typically used when the fluid collection is more anterior or lateral. The needle is inserted around the fourth or fifth intercostal space.
• Suprasternal
  • This approach is less commonly used but can be beneficial in certain situations, especially when other approaches are not viable.

Once the needle reaches the pericardial space, a catheter drains the fluid. Agitated saline or contrast may sometimes be used to confirm correct catheter placement.

Fluoroscopy-Guided Pericardiocentesis

This method is used when echocardiography is unavailable or if a case requiring more invasive hemodynamic monitoring. The patient is positioned supine, and fluoroscopy is used to visualize the needle placement. Local anesthesia is administered at the planned insertion site, typically the subxiphoid area. Once the needle is advanced towards the pericardium, a contrast dye may be injected to confirm the correct placement within the pericardial sac. A guidewire is inserted, followed by the advancement of a pigtail catheter for fluid drainage. Fluoroscopy provides real-time guidance and can be particularly useful in complex cases requiring precise needle placement.

Needle Insertion and Catheter Placement

A sheathed needle is used to access the pericardial sac for both echocardiography and fluoroscopy-guided techniques. Once the needle reaches the pericardial space and fluid is aspirated, the needle is removed, leaving the catheter in place for drainage. In some cases, the catheter’s position may be confirmed by injecting agitated saline, producing bubbles in the pericardial space visible on echocardiography.

Technical Considerations in Pericardiocentesis

• Differentiating pericardial fluid from cardiac blood
  • Clinical judgment is crucial, as no single method is entirely definitive.
  • Clotting behavior
    • Blood from a cardiac chamber typically forms a clot, whereas pericardial fluid does not.
  • Hematocrit levels
    • Pericardial fluid generally has a lower hematocrit or hemoglobin level than intracardiac blood.
  • Fluorescein test
    • Injection of fluorescein into the heart may result in visible fluorescence in the conjunctivae.
  • Agitated saline test
    • Injecting agitated saline through the catheter and observing for bubbles via echocardiography confirms catheter placement within the pericardial space.
• Intracardiac needle entry
  • If the needle inadvertently enters a heart chamber, it should be promptly removed, and the patient should be closely monitored.
  • In most instances, no significant blood leakage into the pericardial space will occur. However, if blood accumulates, a cardiac surgeon's emergency notification is imperative.[13]
• Drain placement
  • A drain is often necessary for ongoing fluid accumulation, particularly in chronic or recurrent effusions.
  • If a pericardial drain is placed, the clinical staff should record the drainage every shift.[2]

Postprocedure Management

After fluid removal, careful monitoring is required to assess for complications such as arrhythmias, bleeding, or recurrent effusion. Fluid analysis may be performed to help determine the underlying etiology of the effusion. Further intervention, including pericardial window or surgical drainage, may be necessary in cases of complications or persistent effusion. Effective management involves addressing the underlying etiology of the effusion, such as infection, malignancy, or systemic diseases, and treating comorbid conditions that may exacerbate pericardial pathology.

Complications

When performed by experienced clinicians, pericardiocentesis generally leads to favorable outcomes, but complications occur in 5% or more cases.[14] Most complications present early and require immediate attention. Using ultrasound or other imaging modalities is highly recommended to lower the risk of complications.[15][16] Clinicians performing pericardiocentesis should be in or have access to direct contact with cardiothoracic surgical specialists who are ideally in the same facility.

Complications of pericardiocentesis include injury to the myocardium with the potential for hemorrhage into the pericardium, leading to iatrogenic cardiac tamponade. Aberrant needle placement may also injure the great vessels, coronary arteries, liver or abdominal viscera, or pneumothorax.[14] The phrenic nerve runs through the pericardium and can be damaged during the procedure. Other complications include arrhythmia and infection.[2] 

The acute decompression of the pericardial sac via pericardiocentesis can result in vasovagal bradycardia in up to 25% of patients; clinicians must be aware of and prepared for this potential complication.[17] Additionally, acute cardiac decompression syndrome, characterized by hemodynamic decompensation and pulmonary edema, can occur; the syndrome is most likely to appear when large volumes of pericardial fluid are rapidly drained.[18]

Pericardiocentesis can result in iatrogenic injury to nearby critical structures such as the right main and left anterior descending coronary arteries, lungs, and diaphragm. These risks are reduced but not eliminated by performing the procedure with guided imaging. The following list summarizes the complications:  

• Chamber laceration
• Internal mammary artery injury
• Intercostal vessel injury
• Coronary injury
• Pneumothorax
• Arrhythmias
• Hypotension and vasovagal response
• Liver or peritoneal puncture
• Infection
• Death

Clinical Significance

Pericardiocentesis is a potentially life-saving intervention, particularly in the context of acute cardiac tamponade, where failure to recognize and treat hemodynamic decompensation promptly can lead to death.[19] Beyond emergency scenarios, the procedure is employed for diagnostic evaluation and managing symptomatic pericardial effusions, including those caused by iatrogenic injuries such as hemopericardium following catheterization or pacemaker lead perforation. Given the frequency with which cardiologists encounter pericardial diseases—including pericarditis, malignancy-associated effusions, and autoimmune conditions—proficiency in pericardiocentesis is essential for both therapeutic and diagnostic purposes. Furthermore, as complex electrophysiology and structural heart interventions grow in prevalence, mastery of image-guided pericardiocentesis using echocardiography or fluoroscopy has become increasingly important for modern cardiologists.

Enhancing Healthcare Team Outcomes

Effective execution of pericardiocentesis requires a multidisciplinary approach involving clinicians, nurses, pharmacists, and other healthcare professionals. Clinicians such as cardiologists are responsible for procedural planning, technical execution, and management of complications—ensuring alignment with the patient’s clinical status. Nurses are crucial in patient preparation, monitoring vital signs, and maintaining sterile fields to reduce infection risk. Pharmacists support hemodynamic stability by ensuring the availability and proper dosing of analgesics, sedatives, or emergency medications, such as vasopressors. Effective team performance hinges on clear interprofessional communication, such as using standardized protocols and handoff tools to ensure all team members understand the procedural plan and anticipate potential complications.

Strategic care coordination enhances patient-centered outcomes and safety. For example, integrating diagnostic imaging specialists ensures precise needle guidance, while anesthesiologists manage sedation and pain control. Following the procedure, coordinated efforts between all team members support vigilant postprocedure monitoring to detect early signs of complications like tamponade recurrence or infection. Regular interdisciplinary discussions during rounds foster a shared understanding of the patient’s condition, allowing timely adjustments to care plans. This collaborative approach optimizes procedural success and strengthens patient trust, safety, and satisfaction through seamless, team-based care delivery.