Effect of high-frequency oscillation on reduction of atelectasis in perioperative patients: a prospective randomized controlled study

Figures & data

Figure 1. CONSORT flow diagram.

Table 1. Baseline characteristics.

Variables	Control (n = 31)	HFO (n = 33)	P
Gender(n)	15(F)/16(M)	16(F)/17(M)
Age(year)	58.4839	55.8064	P = 0.7814
Height(cm)	166.6129	167.0313	P = 0.3607
Weight(kg)	64.3548	65.9313	P = 0.5395
BMI	23.04 ± 0.5988	23.56 ± 0.6535	P = 0.5603
Surgery time(min)	63.58 ± 1.963	62.70 ± 1.790	P = 0.7401
Pneumoperitoneum time(min)	53.35 ± 1.799	56.03 ± 1.622	P = 0.2725
Anesthesia time(min)	84.77 ± 2.542	84.21 ± 1.488	P = 0.8471

Values are shown in number or mean ± SD.

Figure 2. Comparison of lung ultrasound clips.

Figure 3. B-line scores (a) and Consolidation scores (b) from T1 to T3 for patients who received no intervention (control group, black box) or continuous high-frequency oscillation therapy (HFO group, grey box).

Figure 4. Blood gas analysis.

Table 2. Comparison of perioperative variables between groups.

Variables	Control Group (n = 31)	HFO Group (n = 33)	95% CIs for OR or mean difference	P
Atelectasis incidence(T1)	22(71.0%)	23(69.7%)	1.06(0.36 to 3.11)	0.911
Atelectasis incidence(T2)	28(90.3%)	17(51.5%)	8.78(2.23 to 34.66)	0.002
Atelectasis incidence(T3)	28(90.3%)	19(57.5%)	6.88(1.74 to 27.24)	0.006
Desaturation in PACU	12(38.71%)	3(9.09&)	6.32(1.57 ∼ 25.35)	0.009
Minimum SpO2 in PACU	93 [91 to 96]	97 [94 to 98]		0.004
postoperative respiratory events(n)	3(9.6%)	2(6.1%)	1.66(0.26 to 10.68)	0.593
Length of Hospitalization(days)	3.2 ± 2.0	3.0 ± 1.5	0.2(-4.97 ∼ 5.37)	0.837

Data are presented in number, median [IQR] or mean ± SD. T1: Time after tracheal intubation, T2: Time at the end of surgery. T3: Discharge from the PACU (postanaesthesia care unit). OR: odds ratio, CI: confidence interval. Desaturation is defined as a pulse oximeter value of ≤95%.

Data availability

The data that support the findings of this study are available on request from the corresponding author, S.Y. Li. The data are not publicly available due to their containing information that could compromise the privacy of research participants.