Effects of inverse ratio ventilation combined with lung protective ventilation on pulmonary function in patients with severe burns for surgery

Figures & data

Table 1. General conditions between the two groups.

Groups	n	ASA grade	Age (y)	Sex (M/F)	Operation duration (min)	Amount of bleeding (ml)
Control	40	28/12	49.73 ± 6.15	32/8	176.32 ± 47.58	1018.34 ± 76.33
Experiment	40	30/10	46.87 ± 7.24	31/9	184.07 ± 39.61	987.25 ± 81.54

ASA, American Society of Anesthesiologists; M, male; F, female; y, year; min, minutes; ml, milliliter. No significant (p > 0.05) difference existed between the two groups.

Table 2. Blood gas indexes in two groups (mean ± standard deviation).

Variables	Group	T0	T1	T2
OI (mmHg)	Control	304.17 ± 43.51	254.53 ± 61.42	228.17 ± 58.21
	Experiment	308.60 ± 48.29	306.18 ± 59.07*	294.10 ± 54.18*
PaCO2 (mmHg)	Control	39.04 ± 10.03	40.26 ± 9.23	42.17 ± 9.61
	Experiment	37.15 ± 9.42	39.80 ± 9.74	41.53 ± 10.16
D(A-a)O2 (mmHg)	Control	151.34 ± 15.21	164.39 ± 54.41	182.37 ± 36.48
	Experiment	149.27 ± 13.54	132.71 ± 37.69*	124.90 ± 41.73*
Lac (mmol/L)	Control	1.34 ± 0.21	1.38 ± 0.25	1.40 ± 0.23
	Experiment	1.32 ± 0.26	1.31 ± 0.32	1.28 ± 0.19*

OI, oxygen index; PaCO₂, partial pressure of carbon dioxide; PaO₂, partial pressure of oxygen; D(A-a)O₂, alveolar–arterial difference of oxygen partial pressure; Lac, lactic acid; T0, before operation; T1, 1 h after start of the operation; T2, at the end of the operation. *p < 0.05 compared with the control group.

Table 3. Respiratory parameters in two groups (mean ± standard deviation).

Variables	Group	T0	T1	T2
TV (ml)	Control	534.28 ± 26.70	532.47 ± 25.98	533.34 ± 26.47
	Experiment	530.51 ± 28.07	434.14 ± 27.15*	435.37 ± 26.38*
Ppeak (cmH2O)	Control	20.35 ± 1.32	21.58 ± 1.74	21.61 ± 1.57
	Experiment	20.05 ± 1.27	18.16 ± 1.39*	18.24 ± 1.48*
Pmean (cmH2O)	Control	11.47 ± 1.20	8.27 ± 1.45	8.43 ± 1.40
	Experiment	11.14 ± 1.03	11.85 ± 1.31*	11.76 ± 1.18*
PEEP (cmH2O)	Control	2.03 ± 0.14	2.05 ± 0.11	2.06 ± 0.13
	Experiment	2.10 ± 0.12	6.35 ± 0.18*	6.28 ± 0.21*
Cdyn(ml/cmH2O)	Control	31.36 ± 2.54	28.23 ± 2.61	29.31 ± 3.07
	Experiment	30.27 ± 3.18	35.17 ± 2.94*	36.25 ± 2.14*

TV, tidal volume; Ppeak, peak airway pressure; Pmean, mean airway pressure; PEEP, positive end-expiratory pressure; Cdyn, pulmonary dynamic compliance; T0, before operation; T1, 1 h after start of the operation; T2, at the end of the operation. *p < 0.05 compared with the control group. Here, the PEEP in the control group was produced by the mechanical ventilator itself.

Table 4. Inflammatory factors in two groups (mean ± standard deviation).

Variables	Group	T0	T1	T2
IL-6 (pg/ml)	Control	43.24 ± 21.32	61.13 ± 18.41	73.40 ± 20.25
	Experiment	49.75 ± 26.43	36.54 ± 17.53*	34.26 ± 16.47*
IL-10 (pg/ml)	Control	28.13 ± 11.25	34.62 ± 9.56	39.24 ± 8.47
	Experiment	29.46 ± 10.37	26.47 ± 10.24*	25.64 ± 9.36*

IL, interleukin; T0, before operation; T1, 1 h after start of the operation; and T2, at the end of the operation. *p < 0.05 compared with the control group.

Table 5. Complications in the lungs after surgery (case no., %).

Group	Ventilator-assisted breathing	Hypoxemia	Increased expectoration	Increased lung texture or exudation
Control	5 (12.50)	11 (27.50)	18 (45.00)	15 (37.50)
Experiment	3 (7.50)*	4 (10.00)*	9 (22.50)*	7 (17.50)*

*p < 0.05 compared with the control group.