Utility of point-of-care ultrasound for guidance of ultrafiltration goal in a patient with end stage renal disease and acute hypoxic respiratory failure following 2 weeks on mechanical ventilation

Abstract

Point-of-care ultrasound is a bedside tool that is increasingly being used as part of the physical examination to evaluate fluid status. Cardiac ultrasound for assessment of volume status focuses on evaluating left ventricular ejection fraction, presence of pericardial effusion, right ventricular size, inferior vena cava size and collapsibility, and stroke volume measurement at the left ventricular outflow tract. Another way in which POCUS can be used to assess for fluid overload is the use of mitral inflow doppler to measure early diastolic transmitral flow velocity (E) and tissue doppler to measure early diastolic mitral annular velocity (e’). The ratio of E/e’ is then used as an estimation of left ventricular filling pressure. This is a case where a 54-year-old female with end stage renal disease presents with hypoxic respiratory failure and is found to have diffuse bilateral airspace opacities on chest radiograph. E/e’ was used to determine the etiology of the patient's undifferentiated pulmonary infiltrates and guide fluid removal through ultrafiltration. Ultrafiltration was performed with subsequent improvement in E/e’ and the patient was successfully weaned off mechanical ventilation.

Keywords

• End stage renal disease
• Point-of-care ultrasound
• Respiratory failure
• Ultrafiltration