Association of Total Fluid Intake and Output with Duration of Hospital Stay in Patients with Acute Pancreatitis
Table 4
Associations of total fluid intake and urine output at 24 and 48 hours after hospital admission with length of hospital stay.
Variable
Single-variable analysis
Multivariable analysis
Multiplicative effect on mean LOS (95% CI)
value
Multiplicative effect on mean LOS (95% CI)
value
At 24 hours following hospital admission
Normal saline (>2000 mL)
71
1.14 (0.70, 1.85)
0.60
0.85 (0.57, 1.25)
0.41
Lactate ringer (>250 mL)
71
0.71 (0.44, 1.15)
0.16
1.22 (0.83, 1.79)
0.31
Oral intake (>0 mL)
71
0.60 (0.37, 0.96)
0.035
0.83 (0.56, 1.21)
0.33
Other intake (>2 mL)
71
2.38 (1.51, 3.75)
0.0002
1.72 (1.16, 2.54)
0.007
Total fluid intake (per 1000 mL increase)
71
1.04 (0.95, 1.14)
0.38
1.06 (0.99, 1.13)
0.12
Urine output (per 500 mL increase)
71
0.89 (0.80, 0.99)
0.030
0.98 (0.89, 1.07)
0.64
Total fluid output (per 500 mL increase)
71
1.06 (0.98, 1.15)
0.17
1.03 (0.96, 1.10)
0.47
Total intake minus total output (per 2500 mL increase)
71
1.01 (0.84, 1.21)
0.93
1.11 (0.94, 1.32)
0.22
Total intake minus urine output (per 2500 mL increase)
71
1.27 (0.99, 1.63)
0.064
1.21 (1.00, 1.47)
0.048
Ratio of total intake/total output (doubling)
71
0.98 (0.89, 1.07)
0.65
1.00 (0.93, 1.08)
0.91
Ratio of total intake/urine output (doubling)
71
1.13 (1.01, 1.27)
0.030
1.02 (0.95, 1.10)
0.59
At 48 hours following hospital admission
Normal saline (>2700 mL)
65
0.99 (0.54, 1.80)
0.96
0.81 (0.50, 1.32)
0.40
Lactate ringer (>1000 mL)
65
0.67 (0.37, 1.22)
0.19
1.40 (0.85, 2.33)
0.19
Albumin (>0 mL)
65
4.75 (2.01, 11.22)
0.0004
2.57 (1.25, 5.31)
0.011
Blood products (>0 mL)
65
4.21 (1.73, 10.24)
0.002
1.98 (0.89, 4.44)
0.096
Oral intake (>480 mL)
65
0.56 (0.31, 1.02)
0.057
0.82 (0.50, 1.36)
0.45
D5W or D10W (>0 mL)
65
3.90 (1.58, 9.63)
0.003
2.06 (0.99, 4.28)
0.054
Other intake (>50 mL)
65
4.52 (2.66, 7.69)
<0.0001
2.95 (1.95, 4.47)
<0.0001
Total fluid intake (per 1000 mL increase)
65
0.99 (0.91, 1.07)
0.76
1.02 (0.95, 1.10)
0.54
Urine output (per 500 mL increase)
65
0.88 (0.83, 0.95)
0.004
0.96 (0.90, 1.02)
0.18
Total fluid output (per 500 mL increase)
65
1.02 (0.93, 1.11)
0.67
1.00 (0.94, 1.06)
0.88
Total intake minus total output (per 2500 mL increase)
65
0.95 (0.78, 1.16)
0.63
1.06 (0.89, 1.26)
0.51
Total intake minus urine output (per 2500 mL increase)
65
1.25 (0.98, 1.58)
0.071
1.14 (0.95, 1.38)
0.16
Ratio of total intake/total output (doubling)
65
0.91 (0.75, 1.09)
0.30
0.98 (0.83, 1.14)
0.75
Ratio of total intake/urine output (doubling)
65
1.24 (1.07, 1.44)
0.005
1.04 (0.94, 1.16)
0.45
LOS = length of stay; CI = confidence interval. Multiplicative effects, 95% CIs, and values result from negative binomial regression models. For analysis involving total fluid intake and urine output at 24 hours following hospital admission, multivariable models were adjusted for respiratory rate, systolic blood pressure, BISAP score, hematocrit, bicarbonate, and BUN. For analysis involving total fluid intake and urine output at 48 hours following hospital admission, multivariable models were adjusted for respiratory rate, systolic blood pressure, BISAP score, bicarbonate, and BUN. One fewer variable was adjusted for in the multivariable models involving total fluid intake and urine output at 48 hours following hospital admission due to the smaller sample size utilized in that analysis. For measures involving total fluid intake, urine output, and total fluid output at 24 and 48 hours after hospital admission, these were assessed as continuous variables in negative binomial regression analysis. Specific types of fluid intake were all assessed as binary categorical variables based on the sample median (≤median versus >median) in negative binomial regression analysis due to the high concentration of zero values for most of the specific types of fluid intake. Only specific types of fluid intake for which there were more than five patients with a value greater than zero were assessed for the association with LOS.
