Dynamic ultrasound monitoring of intraperitoneal effusion for predicting complications after laparoscopic gastrectomy

Table 3 Assessment of effusion volume, n (%)/mean ± SD

Time point	Effusion volume (mL)	Mild effusion	Moderate effusion	Massive effusion	F/χ2	P value
POD1	38.25 ± 15.62	25 (31.25)	3 (3.75)	0 (0.00)	35.462	< 0.001
POD3	89.74 ± 42.11	22 (27.50)	31 (38.75)	5 (6.25)
POD7	63.38 ± 28.94	33 (41.25)	10 (12.50)	4 (5.00)
Level distribution	-				29.751	< 0.001

P < 0.05 indicated significant difference. Severity was classified as mild (< 50 mL), moderate (50-200 mL), or massive (> 200 mL). P value for volume trend from linear mixed model; distribution comparison from χ² test. POD: Postoperative day.