A restrictive dose of crystalloids in patients during laparoscopic cholecystectomy is safe and cost-effective: prospective, two-arm parallel, randomized controlled trial

Figures & data

Figure 1 Flow chart of the study.

Table 1 Baseline demographics, anesthesiologic, and surgical data

Variable	Restrictive group (n = 40)	Low liberal group (n = 40)	High liberal group (n = 40)	p-values (p1/p2)
Sex (female/male)	27/13	26/14	28/12	0.78/0.77
Age (years)	50 (40.3–62.5)	58 (44.5–69)	56.5 (42.3–66.5)	0.094/0.387
Preoperative weight (kg)	82 (74–93.5)	79.5 (70–92)	80.5 (75–92)	0.212/0.234
Height (cm)	167 (160–175)	166 (160–170)	165 (161–172)	0.22/0.24
Body mass index (kg/m^2)	29 (27–31.6)	27 (25–32)	28 (26–33)	0.99/0.64
Body surface area (m^2)	1.9 (1.8–2.1)	1.8 (1.7–2)	1.9 (1.7–2)	0.29/0.59
Duration of surgery (minutes)	57 (50–65)	57.5 (48.8–71)	58.5 (50–73.3)	0.75/0.72
Duration of anesthesia (minutes)	70 (60–80)	70 (60–92.5)	70 (63.8–100)	0.49/0.47
Blood loss (mL)	40 (25–50)	40 (20–56)	60 (35–86)	0.94/0.003
Fluids infused intraoperatively (mL)	99 (73–113)	474 (393–602)	1,485 (1,222–1,970)	0.000/0.000
Diuresis intraoperatively (mL)	38 (30–40)	55 (45–66)	90 (74–100)	0.000/0.000
Fluid balance intraoperatively (mL)	−30 (−38 to −70)	296 (247–423)	1,209 (999–1,659)	0.000/0.000
Days of hospitalization	3 (3–4)	3 (3–4)	3 (3–4)	0.054/0.238

Notes: Data are shown as median (25–75 interquartile range). p1 < 0.025 presents statistical differences between the restrictive group and the low liberal group; p2 < 0.025 presents a statistical difference between the restrictive group and the high liberal group.

Figure 2 Box-whisker diagram representing the dynamic changes of SAP (A), DAP (B), MAP (C) and HR (D) before induction of anesthesia (□), immediately after intubation (<img>), when pneumoperitoneum was created (||), and immediately after surgery (═) in the restrictive, low liberal, and high liberal groups.

Notes: The line within the box represents median value, whereas the outer margins of the boxes represent the interquartile range, and the “whiskers”, the range. Levels of statistical significance are marked as follows: *p < 0.017 within the restrictive group, low liberal group, and high liberal group; ^#p < 0.025 between the restrictive group and the low liberal group; and ^$p < 0.025 between the restrictive and high liberal groups.
Abbreviations: SAP, systolic blood pressure; DAP, diastolic blood pressure; MAP, mean arterial pressure; HR, heart rate.

Figure 3 Box-whisker diagram representing the dynamic changes of the cardiac index (CI) (A), SVI (B), and SVRI (C) before induction of anesthesia (□), immediately after intubation (), when the pneumoperitoneum was created (||), and immediately after surgery (═) in the restrictive, low liberal, and high liberal groups.

Notes: The line within the box represents median value, while the outer margins of the boxes represent the interquartile range and the “whiskers”, the range. Levels of statistical significance are marked as follows: *p < 0.017 within the restrictive group, low liberal group, or high liberal group; There was no statistically significant difference between the restrictive group and the low liberal group; and ^$p < 0.025 between the restrictive group and the high liberal group.
Abbreviations: CI, cardiac index; SVI, stroke volume index; SVRI, systemic vascular resistance index.

Table 2 Laboratory data of arterial blood gas values and lactate concentrations at four time points

	Restrictive group				Low liberal group				High liberal group
	T0	T1	T2	T3	T0	T1	T2	T3	T0	T1	T2	T3
pH	7.42 (7.39–7.43)	7.4 (7.37–7.42)*	7.3 (7.29–7.35)*	7.4 (7.38–7.41)*	7.41 (7.39–7.42)	7.4 (7.37–7.43)*	7.33 (7.29–7.35)*	7.38 (7.36–7.4)*	7.41 (7.39–7.43)	7.4 (7.37–7.42)*	7.33 (7.29–7.34)*	7.4 (7.38–7.41)*
pCO2 (kPa)	5.2 (4.9–5.5)	5.4 (5.1–6.15)*	6.4 (5.8–7.2)*	4.9 (4.7–5.2)	5.5 (5.2–5.9)	5.5 (5.1–5.8)	6.35 (5.9–7.6)*	5.1 (4.7–5.3)*	5.4 (5.1–5.7)	5.5 (5.1–5.9)	6.6 (5.9–7.2)*	4.9 (4.6–5.2)*
pO2 (kPa)	11.6 (10.7–13)	18.1 (14–22.5)*	12.15 (10.3–17.5)	12 (10.3–13.8)	11.7 (9.6–13.4)	17.7 (14.3–22.1)*	11.8 (9.8–13.2)	10.9 (9.1–13)	11.4 (9.6–13)	16.9 (13.5–20.9)*	11.7 (8.9–15.7)	10.9 (9.9–12.9)
HCO3 (mmol/L)	25 (23–26)	24.5 (23.3–26)	25 (23–26)	23 (21–24)*	25.5 (24–27)	25 (24–27)	25 (23–26)	22 (20–23)*	25 (23–26)	24.5 (24–26)	25 (23–26)	22 (20–23)*
BE (mmol/L)	0.5 (−1.0 to 2.0)	0 (−1.0 to 1.0)*	−2 (−3.0 to −1.0)*	−2 (−3.0 to −1.0)*	1 (−0.8 to 2.0)	0 (−1.0 to 2.0)*	−2 (−3.0 to −0.3)*	−3 (−4.0 to −1.0)*	0.5 (−1.0 to 2.0)	0 (−2.0 to 0.8)*	−2 (−3.0 to −1.0)*	−2 (−4.0 to −1.0)*
SaO2 (%)	97 (96–98)	99 (98–99)*	96 (94–98)	97 (95–98)	97 (94–98)	99 (98–99)*	96 (94–97)	96 (94–98)	96 (94–98)	99 (97–99)*	96 (92–98)	96 (95–97)
Lactates (mmol/L)	1.29 (1.1–1.75)	1.28 (1.1–1.5)	1.46 (1.25–1.72)	1.06 (0.9–1.32)*	1.2 (1–1.5)	1.1 (0.9–1.4)	1.4 (1.13–1.7)	1.04 (0.9–1.25)*	1.22 (1–1.84)	1.15 (0.95–1.46)	1.44 (1.12–1.67)	1 (0.86–1.26)*

Notes: Data are shown as median (25–75 percentiles range). Levels of statistical significance are marked as follows:

* p < 0.017 compared with preoperative value within all groups; p < 0.025 compared between the restrictive and low liberal groups; and p < 0.025 compared between the restrictive and high liberal groups.

Abbreviations: pH, potential of hydrogen; pCO₂, partial pressure of carbon dioxide; pO₂, partial pressure of oxygen; HCO₃, bicarbonates; BE, base excess; SaO₂, arterial oxygen saturation.

Table 3 Simplified Acute Physiology Score (SAPS) and estimated mortality (%)

	Restrictive group (n = 40)	Low liberal group (n = 40)	High liberal group (n = 40)	p-values (p1/p2)
	Median (IQR 25th–75th) (95% confidence interval)	Median (IQR 25th–75th) (95% confidence interval)	Median (IQR 25th–75th) (95% confidence interval)
SAPS score	23 (19–23)	21 (13.5–26)	23 (20–29)	0.031/0.79
	21–26.5	16–23	21–25.5
Estimated	2.9 (1.4–4.2)	4.2 (1.5–7.2)	5.2 (3.8–9.5)	0.045/,0.001
mortality (%)	1.9–4.2	2.3–5.2	4.2–6.8

Notes: Data are shown as median (25–75 quartiles range) and 95% confidence intervals. Levels of statistical significance are marked as follows: p1 < 0.025 refers to the restrictive group and low liberal group comparisons; p2 < 0.025 refers to the restrictive group and high liberal group comparisons.

Abbreviation: IQR, interquartile range.