This case illustrated a successful pericardiocentesis procedure using subcostal approach, with real-time ultrasound guidance. The contemporary use of ultrasound has allowed pericardiocentesis to be performed at any position surrounding the pericardium [4, 5]. In this case, the subcostal site was chosen, because this was where the image was clearest, and the pericardial collection was largest.

Before the era of ultrasound, subxiphoid or subcostal approach, was the most widely accepted method, due to its high success rate to locate anatomical landmark at Larrey’s triangle [8, 9]. After the introduction of ultrasound, the practice had changed tremendously, and anatomical location for pericardiocentesis varies. Para-apical had been found to be the most common site (63%), followed by subcostal (15%) and parasternal (14%) [6]. The para-apical approach was preferred, because it was usually, where the pericardial space was closest to the probe, and the fluid accumulation was maximal [5, 10].

Osman et al. demonstrated that the left parasternal with medial to lateral approach could provide an excellent visualization of needle trajectory [11]. Under ultrasound guidance, the left parasternal approach avoids injury to the surrounding structures, making the procedure practically free from any complications.

When choosing the site of the emergency pericardiocentesis, the ideal approach for using point-of-care ultrasound guidance should take into consideration the distance of effusion to the probe, image quality, and predicted complications. Stolz et al. predicted that the subcostal approach had the highest complication rate compare to other methods [12]. This was because of its long distance from the skin to the pericardial space, which increased the risk of injury to the liver, blood vessels and bowels. However, subcostal approach might be the preferred option in situations, such as cardiopulmonary resuscitation, or poor view for other approaches due to hyperinflated lungs.

When pericardiocentesis was performed blindly using the subcostal approach, it had a complication rate of 5–20% [6, 8]. In the year 2000, Vayre et al. reported 109 cases of ultrasound-guided subcostal pericardiocentesis with contrast study [13]. However, a 10% rate of right ventricular puncture was still observed. The author concluded that although pericardial contrast injection could help to localize the needle tip, it did not prevent traumatic punctures. This was probably because the procedure was done using a low-frequency phased array transducer, and it was not under true real-time ultrasound guidance [14].

Recently, Law et al. demonstrated that the subcostal approach could still be a safe procedure. He confirmed this using long axis in-plane technique at the subcostal area for pericardiocentesis. The procedure was carried out on 14 post-operative pediatric patients and no complications were observed [15]. In adult patients, the increase of depth of surrounding tissues and structures may affect angulation of the needle and it will be more challenging. In this case, we demonstrated that the in-plane subcostal approach using high-frequency linear probe was feasible in an adult patient.