title: The carina is approximately 1-2 cm above the pericardial reflection among Chinese patients.
abstract: BACKGROUND
  Central venous catheters (CVCs) and central venous pressure (CVP) monitor is essential in fluid resuscitation and management for critically ill patients. Accuracy of the CVP is mainly dependent on the proper position of the catheter tip. Although the X-ray visible carina was generally recommended as the alternative of pericardial reflection (PR) to guide the placement of CVCs, few data was available with respect to the distance between the carina and PR among Chinese patients. The purpose of this study was to explore the topographic relationship between the trachea carina and PR among Chinese patients by using computed tomography (CT) images.
  
  
  METHODS
  CT images of 172 patients who underwent CT pulmonary angiogram or CT angiogram for aorta from January 1, 2013 to November 30, 2013 were retrospectively reviewed. Distances between upper margin of the right clavicular notch, trachea carina, PR and atriocaval junction (ACJ) were calculated using the table positions on axial images.
  
  
  RESULTS
  The mean length of extrapericardial superior vena cava (SVC) was 2.5 cm. For all patients, the PR was lower than the carina by average 1.6 cm.
  
  
  CONCLUSIONS
  Given the PR was average 1.6 cm lower than the carina among Chinese patients, placing the CVCs tip approximate 1.6 cm lower the carina among Chinese patients would be more likely to result in a satisfactory placement.
authors: Department of Critical Care Medicine, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310016, China.
authors: Kong-Han
authors: KH
authors: Pan
authors: Department of Critical Care Medicine, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310016, China.
authors: Dan-Yan
authors: DY
authors: Gu
authors: Department of Critical Care Medicine, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310016, China.
authors: Jian-Cang
authors: JC
authors: Zhou
authors: Department of Critical Care Medicine, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310016, China.
authors: Hong-Chen
authors: HC
authors: Zhao
keywords: Central venous catheter (CVC); carina; pericardial reflection (PR)