Enrollment and other trial activities have temporarily paused due to COVID-19 and are expected to resume in the future; This is not a suspension of IRB approval

The overall goal of this multicenter project is to characterize the expected normal range of Peripheral IntraVenous Volume Analysis (PIVA) values during a euvolemic state, and how those ranges may be altered by comorbidities; the relationship between PIVA and intravenous volume administration during resuscitation of infected patients with presumed hypovolemia; and, the relationship between PIVA and volume decreases during diuresis in acute heart failure patients with hypervolemia.

The determination of volume status remains a clinical challenge in medicine. Patients may develop hypovolemia (too little fluids in the vascular space) due to conditions such as hemorrhage, dehydration, or infection with vascular leak. Alternatively, patients may become hypervolemic (too much fluids in the vascular space), due to conditions such as heart failure, renal failure, or iatragenic over-resuscitation all of which overwhelm the kidney's ability to regulate intravascular volume status. In clinical practice, clinicians strive to return patients to euvolemia (the "right" volume status) through the administration of intravenous fluids or diuretics which remove fluids to achieve homeostasis. While there are a number of proposed clinical exam findings (e.g. dry mucous membranes or skin turgor), measurements (e.g. central venous pressure), or laboratory tests (e.g. blood urea nitrogen), none are precise or universally accepted as reliable methodologies to assess volume status.

The goal of this study is to perform a prospective observational study on three distinct cohorts during ED presentation to assess the variability and performance of PIVA in tracking volume status.

Control Cohort (Presumed Euvolemia)

Inclusion Criteria:

• Age > 18 years old
• Assessed as "euvolemic" by treating physician

Exclusion Criteria:

• History of any type of decreased oral intake or volume loss (e.g. diarrhea, vomiting, etc)

• History of a fever

• History of bleeding

• Any acute illness expected to alter volume

• Known or suspected pregnancy

• Active irregular heart rhythm

• In the opinion of the treating physician, no anticipated intravenous fluid administration

• History of chronic or end stage renal disease

• Liver failure

• History of Acute heart failure

• Presence of abnormal vital signs (90 < HR < 60; 180 < SBP < 110, respiratory rate > 20, pulse ox < 92% or need for supplemental oxygen, 99.0 < temperature < 96).

  2 additional group will be included in this euvolemic group

• Non-elderly patients (age < 50 year) without any comorbid illnesses and

• Age >65

• Diabetes on medications

• Hypertension on medications

• Vascular disease defined by history of peripheral vascular disease, stroke, MI

Note: patients that receive >250 cc of IVF will be excluded from analysis.

Infection Cohort (Presumed Hypovolemia)

Inclusion Criteria:

• Age > 18 years old
• An accessible intravenous catheter is in place
• Known or suspected infection as assessed by the clinical team
• Intention to admit to the hospital
• Anticipated administration of intravenous fluids per clinical team

Exclusion Criteria:

• Clinical exam consistent with volume overload
• Known or suspected pregnancy
• Patients with a history of chronic renal insufficiency or end-stage renal disease
• Patients with a history of acute heart failure

Acute Heart Failure (Hypervolemic cohort)

Inclusion Criteria:

• Age > 17 years old
• An accessible intravenous catheter is in place
• Primary clinical diagnosis of CHF
• Meet 2 of the three criterion:
• X-ray diagnosis
• Elevated bnp from known baseline
• Clinical diagnosis
• Received or intent to administer a diuretic agent
• Intent to admit to the hospital for anticipated > 24 hour period

Exclusion Criteria:

• History of any type of decreased oral intake or volume loss (e.g. diarrhea, vomiting, etc)
• History of a fever
• History of bleeding
• Known or suspected pregnancy
• Active irregular heart rhythm
• History of dialysis dependent end stage renal disease

Presumed Euvolemia cohort: This cohort is recruited to help to define what a "normal" PIVA value should be during a state of presumed euvolemia.

Presumed Hypovolemia cohort: This is a cohort of patients with suspected infection and enriched with categories of sepsis patients.

Hypervolemic cohort: This is a cohort of patients with a diagnosis of Congestive Heart Failure (CHF) who are being admitted to the hospital.