Controlled low central venous pressure reduces blood loss and transfusion requirements in hepatectomy

Table 1 Baseline characteristics of the included trials

Ref.	Disease	Sample size(LCVP/control)	LCVP technique	Transfusion trigger	Methodology score	Blinding (patient/surgeon/anesthesiologist)	Lost to follow-up
Liu et al[15] 2008	Hepatocellular carcinoma	23/23	Trendelenburg’s posture, nitroglycerine, furosemide, control of infusion speed	Hb < 80 g/L	3	Yes/no/no	0/46
Wang et al[16] 2006	Hepatocellular carcinoma	25/25	Trendelenburg’s posture, limiting the volume of infusion, nitroglycerine, furosemide	Hb < 80 g/L	4	Yes/no/no	0/52
Kato et al[17] 2008	Primary liver cancer, metastatic liver tumor	43/42	Clamping the infrahepatic inferior vena cava	Not reported	2	No/no/no	0/85
Liu et al[18] 2005	Not reported	30/30	Trendelenburg’s posture, isoflurane, fentanyl, limiting the volume of infusion, nitroglycerine	Blood loss exceeding 25% of the blood volume or Hb < 80 g/L	1	No/no/no	0/50
El-Kharboutly et al[19] 2004	Not reported	20/20	Nitroglycerine	Not reported	3	No/no/no	0/40

LCVP: Low central venous pressure.

Table 2 Sensitivity analysis

	Studies (n)	MD (95%CI)	P value
Studies published in full texts	4
Blood loss (mL)	4	-348.24 (-553.34, -143.14)	0.0009
Blood transfusion (mL)	4	-246.87 (-427.06, -66.69)	0.007
Duration of operation (min)	2	-8.47 (-33.94, 17.01)	0.51
Studies published in English	4
Blood loss (mL)	4	-394.84 (-624.14, -165.53)	0.0007
Blood transfusion (mL)	3	-416.00 (-998.29, 166.30)	0.16
Duration of operation (min)	3	-18.89 (-35.18, -2.59)	0.02
High-quality studies	3
Blood loss (mL)	3	-488.64 (-730.38, -246.89)	< 0.0001
Blood transfusion (mL)	2	-416.00 (998.29, 166.30)	0.16
Duration of operation (min)	3	-18.89 (-35.18, -2.59)	0.02

Table 3 Patient harm

Ref.	Harm measure	Results
Liu et al[15] 2008	Renal function	No significant differences in BUN and Cr on pre- and post-operative d 1, 3 and 7 between LCVP and control group. Values all within the normal range in both groups
Wang et al[16] 2006	Liver and renal function	There were no significant differences in ALT, TBIL, and Cr on post-operative d 1, 3, and 7 between the two groups. BUN was significantly higher in the control group than in the LCVP group, but was within the normal range in both groups
	Post-operative morbidity	Post-operative complications included biliary fistula, gastrointestinal bleeding, pleural effusion and subphrenic fluid collection, with an incidence of 20% (5/25) in the LCVP group and 24% (6/25) in the control group
Kato et al[17] 2008	Renal function	There were no significant intergroup differences in the values of BUN and creatinine on postoperative 1, 3, and 5 d
	Postoperative morbidity and mortality	There was no morbidity related to IVC clamping and no mortality in the two groups
Liu et al[18] 2005	Renal functionHemodynamic stability	No significant differences in BUN and Cr at postoperative 24 h between the two groups. Systolic blood pressures in the LCVP group were lower than those in the control group
El-Kharboutly et al[19] 2004	Not reported	Not reported

LCVP: Low central venous pressure; IVC: Infrahepatic vena cava; BUN: Blood urea nitrogen.