Table 1.

Select characteristics of included studies.

Order	Authors	Year	Setting	Type of study	Sample size	No. of fluid challenge	Method for indices	Infusion volume	Hemodynamic end point	Tidal volume, mL kg−1	Compliance, mL cm H2O−1)
1	De Backer et al.16	2005	Critically ill patients	Prospective cohort	33	33	PAC	1000 mL CR or 500 mL HES 10%	Increase in CI ⩾ 15%	6.3 (6.0-7.1)	26.0 (23.0-33.0)
2	Huang et al.24	2008	Critically ill patients	Prospective cohort	22	22	PAC	500 mL HES	Increase in CI ⩾ 15%	6.4 (5.7-1)7.	26.1 (18.5-33.7)
3	Auler et al.25	2008	Post cardiac surgery	Prospective cohort	59	59	PAC	20 mL kg-1 LR	Increase in CI ⩾ 15%	8.0	NR
4	Vallée et al.26	2009	Critically ill patients	Prospective cohort	42	42	PiCCO	6 mL kg−1 HES	Increase in CI ⩾ 15%	6.0 (6.2-7.3)	27.0 (23.0-35.0)
5	Muller et al.18	2010	Critically ill patients	Prospective cohort	57	57	PAC o PiCCO	250 or 500 mL saline or HES	Increase in SVI ⩾ 15%	6.0 (4.8-7.8) IBW	28.0a
6	Lakhal et al.19	2011	Critically ill patients	Prospective cohort?	65	65	PAC o PiCCO	500 mL of gelatin	Increase in CO ⩾ 10%	6.9 (5.95-7.85) PBW	40.4 (24.6-56.2)
7	Oliveira-Costa et al.27	2012	Critically ill patients	Cross-sectional observational	37	37	PAC	1000 mL saline or LR or 500 mL HES 6%	Increase in CI ⩾ 15%	6.5 (6.0-6.5) IBW	34.0 (19.0-49.0)
8	Monnet et al.17	2012	Critically ill patients	Prospective cohort	28	28	PiCCO2	500 mL saline	Increase in CI ⩾ 15%	7.1 (6.3-7.9) PBW	23.0 (20.0-26.0)
9	Yazigi et al.28	2012	Post cardiac surgery	Prospective cohort	60	60	PAC	7 mL kg−1 HES	Increase in SVI ⩾ 15%	8.0	NR
10	Cecconi et al.29	2012	Post high-risk surgery	Prospective cohort	31	47	LiDCO	250 mL colloid	Increase in SV ⩾ 15%	8.0 IBW	NR
11	Freitas et al.30	2013	Critically ill patients	Prospective cohort	40	40	PAC	7 mL kg−1 HES	Increase in CO ⩾ 15%	6.0 PBW	31.0 (23.6-37.9)
12	Trepte et al.31	2013	Intraoperative high-risk surgery	Prospective cohort	24	72	PiCCO2	300 mL HES	Increase in CI ⩾ 10%	8.0	NR
13	Song et al.32	2014	Intraoperative—cardiac surgery	Prospective cohort	40	40	PAC	6 mL kg−1 HES	Increase in SVI ⩾ 15%	8.0 IBW	NR
14	Ibarra-Estrada et al.33	2015	Critically ill patients	Prospective cohort	19	59	PiCCO	7 mL kg−1 saline	Increase in SVI ⩾ 15%	6.0 (6.0-6.3) PBW	NR
15	Liu et al.34	2016	Critically ill patients	Prospective cohort	96	96	PiCCO	500 mL saline	Increase in CO ⩾ 15%	7.0 (6.2-7.8) mL kg−1	28.0 (15.9-40.1)a
16	Myatra et al.35	2017	Critically ill patients	Prospective cohort	20	30	PiCCO	7 mL kg-1 saline	Increase in CI ⩾ 15%	6.0 (5.8-6.2) PWB	29.0 (21.0-37.0)
17	Biais et al.36	2017	Intraoperative—neurosurgery	Prospective cohort	41	41	ProAQT	250 mL saline	Increase in SVI ⩾ 10%	6.8 (6.3-7.3) ± IBW	38.0 (28.0-48.0)
18	Biais et al.37	2017	Intraoperative—neurosurgery	Prospective cohort	44	88	ProAQT	250 mL saline	Increase in SVI ⩾ 10%	6.9 (6.5-7.2) IBW	42.2a
19	Yonis et al.38	2017	Critically ill patients	Prospective cohort	19	19	PiCCO	500 mL LR	Increase in CI ⩾ 15%	6.0 PBW	30.0 (23.0-39.0)

Abbreviations: CI, cardiac index; CO, cardiac output; CR, crystalloid; HES, hydroxyethyl starch; IBW, ideal body weight; LR, Ringer’s lactate; NA, not available; NR: not reported; PAC, pulmonary artery catheter; PBW, predicted body weight; SV, stroke volume; SVI, stroke volume index; PPV, pulse pressure variation.

Values are expressed as pooled value (95% confidence interval) or median (IQR).

^aCalculated.