title: Ultrasound measurement of inferior vena cava collapse predicts propofol-induced hypotension.
abstract: OBJECTIVE
  Hypotension is a common side effect of propofol, but there are no reliable methods to determine which patients are at risk for significant propofol-induced hypotension (PIH). Ultrasound has been used to estimate volume status by visualization of inferior vena cava (IVC) collapse. This study explores whether IVC assessment by ultrasound can assist in predicting which patients may experience significant hypotension.
  
  
  METHODS
  This was a prospective observational study conducted in the operating suite of an urban community hospital. A convenience sample of consenting adults planned to receive propofol for induction of anesthesia during scheduled surgical procedures were enrolled. Bedside ultrasound was used to measure maximum (IVCmax) and minimum (IVCmin) IVC diameters. IVC-CI was calculated as [(IVCmax-IVCmin)/IVCmax × 100%]. The primary outcome was significant hypotension defined as systolic blood pressure (BP) below 90mmHg and/or administration of a vasopressor to increase BP during surgery.
  
  
  RESULTS
  The study sample comprised 40 patients who met inclusion criteria. Mean age was 55years, (95%CI, 49-60) with 53% female. 55% of patients had significant hypotension after propofol administration. 76% of patients with IVC-CI≥50% had significant hypotension compared to 39% with IVC-CI<50%, P=.02. IVC-CI≥50% had a specificity of 77.27% (95%CI, 64.29%-90.26%) and sensitivity of 66.67% (95%CI, 52.06%-81.28%) in predicting PIH. The odds ratio for PIH in patients with IVC-CI≥50% was 6.9 (95%CI, 1.7-27.5).
  
  
  CONCLUSIONS
  Patients with IVC-CI≥50% were more likely to develop significant hypotension from propofol. IVC ultrasound may be a useful tool to predict which patients are at increased risk for PIH.
authors.affiliation: Department of Emergency Medicine, Thomas Jefferson University, Philadelphia, PA, USA. Electronic address: arthur.au@jefferson.edu.
authors.forename: Arthur K
authors.initials: AK
authors.lastname: Au
authors.affiliation: Department of Anesthesiology, Thomas Jefferson University, Philadelphia, PA, USA.
authors.forename: Dean
authors.initials: D
authors.lastname: Steinberg
authors.affiliation: Department of Emergency Medicine, Thomas Jefferson University, Philadelphia, PA, USA.
authors.forename: Christopher
authors.initials: C
authors.lastname: Thom
authors.affiliation: Department of Family and Community Medicine, Thomas Jefferson University, Philadelphia, PA, USA.
authors.forename: Maziar
authors.initials: M
authors.lastname: Shirazi
authors.affiliation: Department of Emergency Medicine, Thomas Jefferson University, Philadelphia, PA, USA.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Papanagnou
authors.affiliation: Department of Emergency Medicine, Thomas Jefferson University, Philadelphia, PA, USA.
authors.forename: Bon S
authors.initials: BS
authors.lastname: Ku
authors.affiliation: Department of Emergency Medicine, Thomas Jefferson University, Philadelphia, PA, USA.
authors.forename: J Matthew
authors.initials: JM
authors.lastname: Fields
mesh_terms: D000368:Aged; D018686:Anesthetics, Intravenous / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007022:Hypotension / Q000139:chemically induced* / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015742:Propofol / Q000009:adverse effects*; D011446:Prospective Studies; D014463:Ultrasonography; D014682:Vena Cava, Inferior / Q000000981:diagnostic imaging*
chemical_list: D018686:Anesthetics, Intravenous; D015742:Propofol