Research
Low systemic vascular resistance: differential diagnosis and outcome
1 Department of Medicine, Division of Pulmonary Diseases/Critical Care Medicine, The University of Texas Health Science Center at San Antonio, Texas, USA
2 The South Texas Veterans Health Care System, Audie L. Murphy Memorial Veterans Hospital Division, San Antonio, Texas, USA
Critical Care 1999, 3:71-77 doi:10.1186/cc343
Published: 9 June 1999Abstract
Objective
To determine the frequency and prognosis of the various causes of low systemic vascular resistance (SVR).
Design
Analysis of consecutive patients over a 5-year period; retrospective review.
Setting
Medical intensive care unit of a large university hospital.
Patients
Fifty-five patients with unexplained hypotension and a SVR less than 800 dynes × s/cm5.
Background
There are minimal data in the medical literature determining the frequency or outcome of patients with a low SVR that is unrelated to sepsis or the sepsis syndrome. We retrospectively reviewed and analyzed all hemodynamic data in a large university hospital over a 5-year period to determine the frequency and prognosis of the various causes of low SVR. Fifty-five patients with unexplained hypotension and a SVR less than 800dynes×s/cm5were identified.
Main results
Twenty-two patients (Groups 1 and 2) met the criteria for sepsis syndrome. The mean SVR for this group was 445 ± 168 dynes×s/cm5 with an associated mortality of 50%. Group 3 contained 20 patients with possible sepsis. Thirteen patients (Group 4) were nonseptic. The mean SVR of this group was 435 ± 180 dynes × s/cm5 with an associated mortality of 46%. Extremely low SVR (below 450 dynes × s/cm5) was associated with a significantly higher mortality regardless of the etiology.
Conclusions
At least a quarter of patients with hypotension and a low SVR have nonseptic etiologies. The patients with nonseptic etiologies have a similar mortality to septic patients. Clinicians should be aware of the wide spectrum of conditions that induce a low SVR.