Influence of perioperative oxygen fraction on pulmonary function after abdominal surgery: a randomized controlled trial

Table 2 Pulmonary function in 35 patients undergoing surgery for ovarian cancer

	FiO₂ = 0.30	FiO₂ = 0.80	P value
	(n = 15)	(n = 20)
PaO₂/FiO₂ (kPa)
5 min after intubation *	69 [53–71]	60 [47–69]	0.25
30 min after intubation	58 [37–72]	58 [44–67]	0.39
End of anesthesia	58 [40–70]	57 [46–67]	0.10
90 min after extubation	56 [37–60]	50 [42–57]	0.66
FRC (mL) #
Preoperative	1993 [1610–2240]	1875 [1545–2048]
2 h after extubation	1615 [1375–2318]	1633 [1343–1948]	0.70
Arterial oxygen saturation
Preoperative (%) §	97 ± 2	96 ± 2
≤ 95% 2 h after extubation §	3 (20%)	6 (33%)	0.50
≤ 95% 3 days after surgery §	2 (13%)	7 (35%)	0.15
Atelectasis ‡
No atelectasis	13 (87%)	15 (75%)	0.51
Plate atelectasis	0	0
Segmental atelectasis	1 (7%)	0
Partial lobar atelectasis	0	0
Complete atelectasis of one
lung lobe	0	2 (10%)
Complete atelectasis of one
lung lobe in addition to any of
the above	1 (7%)	3 (15%)

The data are presented as mean ± SD, number of patients (percentage) or median [interquartile range].
P values are calculated by Mann–Whitney test to compare the changes from baseline values between the two groups.
P_aO₂ = arterial oxygen tension; FiO₂ = inspired oxygen fraction; PaO₂/FiO₂ = oxygenation index;
FRC = functional residual capacity.
* Measured at FiO₂ =1.0.
# Preoperative data were missing in 9 patients. Postoperative data were missing in 15 patients (Figure 1).
§ Measured with the patient breathing room air.
‡ Severity of atelectasis assessed according to Joyce et al. modification [20] of Wilcox severity scoring [21].

ISSN: 1756-0500