By Rwo-Wen Huang, MD and Laleh Gharahbaghian, MD, FACEP
A 51-year-old male with metastatic non-small cell lung cancer presented with shortness of breath and bloating. He was normotensive (blood pressure 123/93), tachycardic (heart rate 110), tachypneic (respiratory rate 32), and hypoxic (oxygen saturation 97% on two liters of nasal cannula). Bedside ultrasound revealed a large pericardial effusion (PCE) with tamponade (Figure 1, Video 1, Video 2, Video 3, Video 4) and plethoric inferior vena cava (IVC, Figure 2, Video 5).
Figure 1 and 2: Tamponade showing Right Ventricular Collapse during Diastole and Plethoric IVC
Tamponade has been traditionally taught as a clinical diagnosis with the classic Beck’s triad of hypotension, distended neck veins, and distant heart sounds.1 However, these findings are not widely applicable to tamponade secondary to chronic PCE. Reviews show that hypotension is only present in 14-36% of patients with proven tamponade.2 When the effusion accumulates slowly, the body can maintain a stable blood pressure during the early stages. It compensates for increased intrapericardial pressure with pericardial stretching, elevated heart rate, enhanced systolic emptying, and augmented peripheral vascular resistance.3 This delicate balance can preserve the patient’s blood pressure until the tamponade reaches a critical point when the patient can acutely decompensate into hemodynamic instability.1 This scenario is especially common in malignancy, since cancer is one of the leading causes of chronic PCE with high mortality.1, 2, 4-6 The effusion can result from direct extension of the tumor, metastatic spread, or treatment complication.4 Therefore, it is crucial to realize that normotension does not exclude tamponade. Providers should rely on the more sensitive ultrasound findings, including right sided chambers collapse, full IVC, and respiratory variation of cardiac output (sonographic “pulsus paradoxus”).5
In addition to diagnosis, POCUS has the advantage of procedure planning and guidance. Rather than proceeding blindly, the provider can visualize where the PCE has the greatest pocket with the easiest access. Multiple studies have demonstrated that ultrasound guided pericardiocentesis has a higher success rate with fewer complications compared to traditional landmark technique.6-9 The subxiphoid view is generally considered the best window to evaluate for PCE. Besides the commonly used subxiphoid, transhepatic, parasternal, and apical approaches, recent literature explores novel methods to further improve efficacy and safety, such as in-plane, endobronchial, and endoscopic transesophageal ultrasound.8-11
Tips for US-Guided Pericardiocentesis
In this patient, we identified the best approach in the apical view. Here are a few tips for ultrasound guided pericardiocentesis:
Figure 3. Guidewire seen within pericardial sac
We removed more than 1,200 mL of hemorrhagic PCE from this patient via the apical approach. His vital signs and symptoms improved after the procedure (Video 7), and his level of care progressed from the intensive care unit to the oncology telemetry floor for further management. His CT later revealed metastatic pericardial nodules, which were likely the source of his effusion.