Applicability of a modified EFAST protocol (r-EFAST) to evaluate hemodynamically unstable patients after percutaneous cardiac intervention

Ultrasound is widely regarded as being an accurate and reliable procedure to evaluate patients who have suffered an acute thoraco-abdominal trauma. Developed in late 1990s [1], the Focused Assessment with Sonography for Trauma (FAST) is one of the first ultrasound protocols for the rapid detection of free peritoneal and/or pericardial fluid. The term “Extended FAST” (EFAST) was adapted during the following decade [2] to include the addition of thoracic ultrasound views, encompassing a broader scope for diagnosis of other possible associated injuries, such as hemothorax or pneumothorax. Since its clinical implementation, EFAST has proven to be more reliable than the physical examination [3].

With the continued advancement of imaging equipment and surgical instruments, the application of interventional radiology techniques is becoming more widespread in the diagnostic and therapeutic management of vascular and cardiac diseases. As a result, however, complications related to this procedure have proportionally increased [4, 5]. Percutaneous cardiac interventions have been associated with the following complications; retroperitoneal hematoma, renal injury, aortic wall hematoma, inferior epigastric injury or local vascular complications (acute thrombosis, distal embolization, dissection, poorly controlled bleeding, pseudoaneurysm or arteriovenous fistula). Retroperitoneal bleeding is one of the more serious complications that can occur as the retroperitoneal space has the capacity to harbour large volumes of blood with no clinical signs and symptoms until hypovolemia occurs late in the clinical course [6]. Complications tend to occur in up to 8% of cardiac catheterization, being more frequently associated with therapeutic rather than diagnostic procedures (15.1% vs. 4.6%). The incidence of non-puncture related bleeding ranges from 0.9 to 1.2%, with the retroperitoneal hematoma being the most common finding (0.12–0.5%). Despite its unfamiliar etiology, the hematomas origin might be spontaneous or iatrogenic, which could be secondary to endovascular trauma or the use of anticoagulation drugs during the procedure. Risk factors predisposing to retroperitoneal haemorrhage after percutaneous transfemoral cardiac intervention are the following: the female sex, low platelet count, sheath removal protocol, the use of hydrophilic guide wire [7] and post-procedure anticoagulation, presenting the greatest risk [8].

The purpose of this paper is to explore the usefulness of a modified EFAST protocol (r-EFAST), including the bedside retroperitoneal clinician-performed assessment, to detect retroperitoneal hematoma or renal parenchymal injury in hemodynamically unstable patients after a percutaneous cardiac intervention without any suspected complications during the procedure in the catheterization laboratory.

We will present the cases of three patients with congenital heart disease without a previous medical history of hemorrhagic diathesis, family history of bleeding or lumbar trauma, who have been diagnosed with a retroperitoneal hematoma after percutaneous cardiac intervention using the r-EFAST protocol. r-EFAST is a bedside, rapid ultrasound protocol used to detect retroperitoneal hematoma or parenchymal renal injury. Once the standard EFAST has been performed in the supine position (scanning the upper right and left abdominal quadrants, pericardial, pelvis and anterior thoracic views), patients are adjusted, to a moderate degree, in a lateral decubitus position. This provides a clearer scan of the retroperitoneal space (Fig. 1), by sliding the probe for the upper right and left postero-lateral thoraco-abdominal junction zone, although the pararenal spaces are best shown transverse epigastric view (Fig. 2).

The examinations were carried out using a TOSHIBA with convex array transducer 3.5–5 MHz and a linear array transducer 6–8 MHz. The accesses were obtained on the common femoral artery (two patients left and one patient right), and long 5-French sheaths were advanced. Patients have given their consent for participation in this report.

Standard EFAST can be performed by physicians as a non-invasive bedside tool. It was strictly designed for the rapid detection of free peritoneal/pericardial/pleural fluid and free pleural air benefitting from diagnostic accuracy without a significant inter-operator variability, having a medium sensitivity but high specificity. Point-of-care ultrasound is a significantly more powerful tool when performed in a high prevalence population. The design of new protocols is important in different pathologies and situations such as the case of EFAST in blunt trauma. EFAST has been implemented in other clinical scenarios and ultrasound protocols, such as shocked adult patients (RUSH exam) [9]. In a similar approach, Heller et al. [10] focused the assessment with sonography on human immunodeficiency virus co-infected tuberculosis patients (FASH protocol) to diagnose extra-pulmonary tuberculosis.

The modification in the EFAST technique, r-EFAST, permits the detection of organ injury and/or free fluids in the retroperitoneal space when complications are suspected, such as, hematoma perirenal or kidney injuries in hemodynamically unstable patients after percutaneous cardiac intervention with abdominal pain and/or decreased haemoglobin level. This event is previously suspected by clinical examination and eventually confirmed by bedside ultrasound.

The r-EFAST extends beyond the EFAST for detecting source of bleeding in the retroperitoneum, not contemplated in the original EFAST. Although r-EFAST may likely require additional procedural time in comparison with EFAST, it is highly dependent upon the experience of the physician (“a good FAST exam takes only 30 s”) [11]. We would therefore recommend including r-EFAST as part of training programmes for physicians who assist patients with congenital heart diseases.