The PIEPEAR Workflow: A Critical Care Ultrasound Based 7-Step Approach as a Standard Procedure to Manage Patients with Acute Cardiorespiratory Compromise, with Two Example Cases Presented

Abstract

Critical care ultrasound (CCUS) has been widely used as a useful tool to assist clinical judgement. The utilization should be integrated into clinical scenario and interact with other tests. No publication has reported this. We present a CCUS based "7-step approach" workflow-the PIEPEAR Workflow-which we had summarized and integrated our experience in CCUS and clinical practice into, and then we present two cases which we have applied the workflow into as examples. Step one is "problems emerged?" classifying the signs of the deterioration into two aspects: acute circulatory compromise and acute respiratory compromise. Step two is "information clear?" quickly summarizing the patient's medical history by three aspects. Step three is "focused exam launched": (1) focused exam of the heart by five views: the assessment includes (1) fast and global assessment of the heart (heart glance) to identify cases that need immediate life-saving intervention and (2) assessing the inferior vena cava, right heart, diastolic and systolic function of left heart, and systematic vascular resistance to clarify the hemodynamics. (2) Lung ultrasound exam is performed to clarify the predominant pattern of the lung. Step four is "pathophysiologic changes reported." The results of the focused ultrasound exam were integrated to conclude the pathophysiologic changes. Step five is "etiology explored" diagnosing the etiology by integrating Step two and Step four and searching for the source of infection, according to the clues extracted from the focused ultrasound exam; additional ultrasound exams or other tests should be applied if needed. Step six is "action" supporting the circulation and respiration sticking to Step four. Treat the etiologies according step five. Step seven is "recheck to adjust." Repeat focused ultrasound and other tests to assess the response to treatment, adjust the treatment if needed, and confirm or correct the final diagnosis. With two cases as examples presented, we insist that applying CCUS with 7-step approach workflow is easy to follow and has theoretical advantages. The coming research on its value is expected.

Figure 1

Regions of lung ultrasound examination. There are six examination regions on each side, delineated by parasternal line (PSL), anterior axillary line (AAL), posterior axillary line (PAL), and paravertebral line (PVL) [34, 35].

Figure 2

Abnormal findings of the Focused Ultrasound Assessment on admission of case 1. (a) IVC exam. Fixed and enlarged IVC and hepatic vein represented no fluid responsiveness and maybe hypervolemia. (b) Assessment of diastole. Restrictive diastolic dysfunction was presented and PAOP estimated by E/e' was increased. (c) Lung ultrasound exam. Bilateral multiple B lines, with posterior atelectasis and plural effusion, indicate diffuse sonographic interstitial syndrome.

Figure 3

Chest X-ray exam on admission and the second day of case 1. (a) On admission, bilateral symmetrical infiltration response for pulmonary edema was revealed. (b) The second day, bilateral pulmonary edema was obviously decreased.

Figure 4

Part of lung ultrasound in the repeated ultrasound exam in the next day. Bilateral A-lines in bilateral 1st regions indicate pulmonary edema was obviously decreased.

Figure 5

Abnormal findings of the Focused Ultrasound Assessment on admission of case 2. (a) Heart browse. No circumstances that need immediate life-saving intervention or cardiologist emergency consultation; left ventricle apex balloon. (b) IVC exam. The diameter <1cm representing hypovolemia. (c) Lung ultrasound exam. Right lung massive consolidation (from the 2nd right region to the 6th right region).

Figure 6

Chest X-ray exam of case 2. Large hyperdensity in right lung showing right lung consolidation, which represented right lung pneumonia in this case.