title: Reverse Trendelenburg position is a safer technique for lowering central venous pressure without decreasing blood pressure than clamping of the inferior vena cava below the liver.
abstract: BACKGROUND
  Bleeding remains an important intraoperative complication in patients who undergo hepatectomy. It is generally believed that a reduction in central venous pressure will decrease bleeding from the hepatic venous system. To our knowledge, however, no study has compared the effectiveness of these techniques for controlling bleeding. So we compared the effectiveness of central venous pressure control techniques, such as infrahepatic inferior vena cava clamping, changes in surgical position of the patient, and hypoventilation anesthesia, for lowering central venous pressure.
  
  
  METHODS
  The study group comprised 50 patients who underwent hepatectomy in our department from 2012 through 2013. A central venous catheter was inserted into the right internal jugular vein, and the tip was placed in the superior vena cava. A transducer was placed along the mid-axillary line of the left side of the chest. After opening the abdomen, changes in central venous pressure were measured during inferior vena cava clamping, the reverse Trendelenburg position, the Trendelenburg position, and hypoventilation anesthesia. The inclination relative to the transducer, as measured with an inclinometer, was -10 degrees for the Trendelenburg position and +10 degrees for the reverse Trendelenburg position. The tidal volume was set at 10 mL/kg during conventional anesthesia and 5 mL/kg during hypoventilation anesthesia.
  
  
  RESULTS
  The mean central venous pressure was 8.0 cm H(2)O in the supine position during conventional anesthesia, 5.0 cm H(2)O during inferior vena cava clamping, 5.6 cm H(2)O during reverse Trendelenburg position, 10.6 cm H(2)O during Trendelenburg position, and 7.6 cm H(2)O during hypoventilation anesthesia. The mean central venous pressure during inferior vena cava clamping and reverse Trendelenburg position was significantly lower than that during supine position (P = 0.0017 and P = 0.0231, respectively). The mean central venous pressure during hypoventilation anesthesia was not significantly lower than that during supine position (P = 0.9934). Mean systolic blood pressure was significantly decreased during inferior vena cava clamping (P = 0.0024), but not during reverse Trendelenburg position (P = 0.6344).
  
  
  CONCLUSIONS
  Reverse Trendelenburg position decreased central venous pressure without significantly decreasing the systolic blood pressure, suggesting that it is possible to perform hepatectomy with reverse Trendelenburg position more safely than with inferior vena cava clamping.
authors.affiliation: Department of Surgery, Institute of Gastroenterology, Tokyo Women's Medical University, 8-1 Kawadacho, Shinjuku-ku, Tokyo, 162-0054, Japan.
authors.forename: Godai
authors.initials: G
authors.lastname: Yoneda
authors.affiliation: Department of Surgery, Institute of Gastroenterology, Tokyo Women's Medical University, 8-1 Kawadacho, Shinjuku-ku, Tokyo, 162-0054, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Katagiri
authors.affiliation: Department of Surgery, Institute of Gastroenterology, Tokyo Women's Medical University, 8-1 Kawadacho, Shinjuku-ku, Tokyo, 162-0054, Japan.
authors.forename: Masakazu
authors.initials: M
authors.lastname: Yamamoto
mesh_terms: D000368:Aged; D016063:Blood Loss, Surgical / Q000503:physiopathology / Q000517:prevention & control*; D001794:Blood Pressure / Q000502:physiology*; D002496:Central Venous Pressure / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D018475:Head-Down Tilt / Q000502:physiology*; D006498:Hepatectomy / Q000379:methods*; D006801:Humans; D008297:Male; D056888:Patient Positioning / Q000379:methods*; D012189:Retrospective Studies; D014682:Vena Cava, Inferior / Q000503:physiopathology / Q000601:surgery*
keywords: Bleeding during hepatectomy; Central venous pressure control technique; Infrahepatic inferior vena cava clamping