Integrative Volume Status Assessment

Abstract

Volume status assessment is a critical but challenging clinical skill and is especially important for the management of patients in the emergency department, intensive care unit, and dialysis unit where accurate intravascular assessment is necessary to guide appropriate fluid management. Assessment of volume status is subjective and can vary from provider to provider, posing clinical dilemmas. Traditional non-invasive methods of volume assessment include assessment of skin turgor, axillary sweat, peripheral edema, pulmonary crackles, orthostatic vital signs, and jugular venous distension. Invasive assessments of volume status include direct measurement of central venous pressure and pulmonary artery pressures. Each of these has their own limitations, challenges, and pitfalls and were often validated based on small cohorts with questionable comparators. In the past 30 years, the increased availability, progressive miniaturization, and falling price of ultrasound devices has made point of care ultrasound (POCUS) widely available. Emerging evidence base and increased uptake across multiple subspecialities has facilitated the adoption of this technology. POCUS is now widely available, relatively inexpensive, free of ionizing radiation, and can help providers make medical decisions with more precision. POCUS is not intended to replace the physical exam, but rather to complement clinical assessment, guiding providers to give thorough and accurate clinical care to their patients. We should be mindful of the nascent literature supporting the use of POCUS and other limitations as uptake increases among providers and be wary not to use POCUS to substitute clinical judgement, but integrate ultrasonographic findings carefully with history and clinical examination.

Lung Ultrasound and Caval Indices to Assess Volume Status in Maintenance Hemodialysis Patients

“…Hemodialysis adequacy and volume control are the main pillars of dialysis prescriptions that would translate into severe clinical consequences. Unfortunately, volume management and dry weight measurement decisions are not always straightforward without objective tools that assess VE 23 .…”

“…The lung is the organ system more sensitive to the adverse effects of VE 23 . The most widely validated protocol is 28-zone lung scanning, but it is a cumbersome procedure.…”

Fluid dynamics of life: exploring the physiology and importance of water in the critical illness

“…Water and its distribution through different compartments determine the volume status ( 36 ). The causes of changes in body fluid volumes can be determined by different methods in critical care patients, including anamnesis, physical examination, electrolytes, arterial blood gases and ultrasound ( 37 ).…”

Monitoring the venous circulation: novel techniques and applications

“…An area of increasing interest and innovation in recent years has been the use of two-dimensional point-of-care ultrasound (POCUS) to assess venous pressure [33,34]. Conventionally, POCUS has been used to assess for the presence of pulmonary edema, IVC size and collapsibility, and measurement of elevated JPV.…”