Association between one-session bilateral whole-lung lavage and periprocedural complications in patients with pulmonary alveolar proteinosis: a retrospective cohort study

Table 1 Comparison of the potential confounders between the two groups (N = 175)

Variable	Two-session group	One-session group	Standardized mean difference	P
Age (year)	47 ± 11	45 ± 11	0.170^a	0.318
Sex	35 (72.9%)	84 (66.1%)	0.148^a	0.499
BMI (kg/m²)	23.2 ± 3.6	23.4 ± 3.4	0.057	0.734
Smoking	26 (54.2%)	68 (53.5%)	0.013	> 0.999
DSS			0.407^a	0.124
2	6 (12.5%)	7 (5.5%)
3	13 (27.1%)	37 (29.1%)
4	11 (22.9%)	48 (37.8%)
5	18 (37.5%)	35 (27.6%)
Diffusion dysfunction			0.493^a	0.026^a
1	14 (29.2%)	14 (11.0%)
2	8 (16.7%)	29 (22.8%)
3	9 (18.8%)	37 (29.1%)
4	17 (35.4%)	47 (37.0%)
Preprocedural infection	1 (2.1%)	31 (24.4%)	0.698^a	< 0.001^a
Course of disease (month)	14 [7, 39]	24 [8, 48]	0.080	0.430
Number of previous WLLs	0 [0, 1]	0 [0, 1]	0.113^a	0.213
Surgery year^b	4 [2, 6]	11 [9, 16]	1.814^a	< 0.001^a
Anesthesia duration (min)	397 ± 97	326 ± 79	0.805^a	< 0.001^a
Saline input (L)^c	20.0 [16.0, 24.5]	20.0 [17.4, 24.0]	0.042	0.996

Abbreviations: BMI, body mass index; DSS, disease severity score; WLL, whole lung lavage. Continuous data were expressed as mean ± standard difference (normally distributed data) or median [interquartile range] (non-normally distributed data), and categorical data were described as number (percentage). Age, BMI, and anesthesia duration were analyzed by Student’s t test. Course of disease, number of previous WLLs, surgery year, and saline input were analyzed by Man-Whitney U test. Sex, smoking, DSS, and diffusion dysfunction were analyzed by Chi-square test. Preprocedural infection was analyzed by Fisher’s exact test. ^aStandardized mean difference ≥ 0.1 or P < 0.05. ^bYears since 2000. ^cTotal volume of saline input of both lungs during a WLL procedure

ISSN: 1750-1172