Table 1 Exclusion criteria

Code status limitations precluding critical care management (for example, directives against use of mechanical ventilation or vasopressor agents)

Refusal of patient or designated surrogate decision-maker to provide written informed consent, or inability to obtain consent within 48 hours of diagnosis

Severe cardiomyopathy with left-ventricular ejection fraction < 30%^a

Chronic dialysis-dependent renal failure^a

History of solid organ or bone marrow/stem cell transplantation^a

Preexisting advanced liver disease (Child-Pugh grade C)^a

Organic nitrate therapy^a

Current active bleeding^a

Hematocrit < 22% or < 25% while taking vasopressors^a

Pregnancy or hormone replacement therapy (HRT)^a

More than 48 hours since severe sepsis/septic shock diagnosis

Vascular-access device present in the target upper extremity^b

Absent Doppler signals in target upper extremity

Skin breakdown or soft tissue inflammation involving target upper extremity^a

History of vascular or lymphatic surgery involving target upper extremity^a