title: Impact of individual characteristics on sonographic IVC diameter and the IVC diameter/aorta diameter index.
abstract: BACKGROUND
  The inferior vena cava (IVC) parameters, including its diameter and collapsibility index have been evaluated for fluid status for over 30 years, but little is known about the impacts of patient characteristics on IVC parameters. The purpose of this study was to explore the relationships between individual patient characteristics and IVC parameters in healthy Chinese adult volunteers.
  
  
  METHODS
  From February 2012 to May 2012, 216 healthy volunteers older than the age of 18 years were consecutively enrolled in our study. The individual characteristics and presence or absence of hypertension of each participant were recorded. Sonographic measurements of IVC and abdominal aorta diameter (Ao) were performed (DP-6900; Mindray, Shenzhen, China).
  
  
  RESULTS
  Volunteers ranged in age from 18 to 84 years (43.7 ± 7.8 years), and 50.5% were males. In univariate analyses, maximum IVC diameter (IVCmax) was negatively correlated with age (years) (r = -0.171, P = .012) and positively correlated with sex (men) (r = 0.174, P = .01), height (centimeters) (r = 0.281, P < .001), and body surface area (square meters) (r = 0.173, P = .011). The IVC/Ao index was negatively correlated with age (years) (r = -0.326, P < .001), waist circumference (centimeters) (r = -0.176, P = .01), body mass index (r = -0.173, P = .011), and hypertension (r = -0.186, P = .006). None of the patient characteristics were significantly correlated with percentage collapse of the IVC. Height (centimeters) was the sole significant predictor of IVCmax (R(2) = 0.079, P < .001). Age (years) and body mass index (kilogram/square meter) were independent predictors of the IVC/Ao index (R(2) = 0.123; P < .001 and P = .046, respectively).
  
  
  CONCLUSIONS
  The percentage collapse of IVC and the IVCmax are not substantially influenced by patient characteristics. In contrast, the IVC/Ao index is more susceptible to patient characteristics than IVC.
authors: Department of the Neurology Intensive Care Unit, the First Hospital Affiliated to Jinan University, Guangzhou 510630, Guangdong, China; Department of the General Intensive Care Unit, Dongguan Hospital Affiliated to Medical College of Jinan University, Dongguan 523905, Guangdong, China.
authors: Jianjun
authors: J
authors: Gui
authors: Department of the Pediatric Intensive Care Unit, Dongguan Hospital Affiliated to Medical College of Jinan University, Dongguan 523905, Guangdong, China.
authors: Jiongguang
authors: J
authors: Guo
authors: Department of the Pediatric Intensive Care Unit, Dongguan Hospital Affiliated to Medical College of Jinan University, Dongguan 523905, Guangdong, China.
authors: Fengqiu
authors: F
authors: Nong
authors: Department of the General Intensive Care Unit, Dongguan Hospital Affiliated to Medical College of Jinan University, Dongguan 523905, Guangdong, China. Electronic address: doctorjdx@163.com.
authors: Dongxin
authors: D
authors: Jiang
authors: Department of the Neurology Intensive Care Unit, the First Hospital Affiliated to Jinan University, Guangzhou 510630, Guangdong, China.
authors: Anding
authors: A
authors: Xu
authors: Department of Ultrasound, Dongguan Hospital Affiliated to Medical College of Jinan University, Dongguan 523905, Guangdong, China.
authors: Fan
authors: F
authors: Yang
authors: Department of Ultrasound, Dongguan Hospital Affiliated to Medical College of Jinan University, Dongguan 523905, Guangdong, China.
authors: Qiaozhu
authors: Q
authors: Chen
authors: Department of the General Intensive Care Unit, Dongguan Hospital Affiliated to Medical College of Jinan University, Dongguan 523905, Guangdong, China.
authors: Youping
authors: Y
authors: Lin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001011:Aorta / Q000000981:diagnostic imaging* / Q000502:physiology; D044466:Asian People; D002681:China; D003430:Cross-Sectional Studies; D005260:Female; D006305:Health Status Indicators; D064368:Healthy Volunteers; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D014463:Ultrasonography; D014682:Vena Cava, Inferior / Q000000981:diagnostic imaging* / Q000502:physiology; D055815:Young Adult