Effect of intra-abdominal pressure on respiratory function in patients undergoing ventral hernia repair

Table 1 Changes in abdominal perfusion pressure, blood gases, arterial lactate and dynamic compliance during different study stages

Study stage	AI	VHR	END	SB	1 HR
APP = MAP - IBP	75 (63-82)	74 (66-85)	82 (68-96)	92 (77-98)a	85 (77-96)a
APP = MAP - IGP	74 (65-82)	78 (67-85)	74 (65-82)	90 (78-97)a	85 (77-96)a
PaCO2 (mmHg)	36 (34-39)	36 (33-42)	37 (34-42)	40 (38-49)a	37 (35-40)
EtCO2 (mmHg)	32 (29-35)	30 (27-35)	33 (28-36)	36 (31-39)a	33 (30-35)
Arterial lactate (mmol/L)	0.9 (0.7-1.0)	0.7 (0.6-0.8)	0.8 (0.7-1.0)	1.0 (0.7-1.4)	0.9 (0.8-1.4)
Dynamic compliance (mL/cm H2O)	32 (26-38)	27 (22-32)a	26 (22-30)a

Data are presented as median and interquartile interval.

^aP < 0.05 vs AI values using Wilcoxon’s signed-rank test with Bonferroni correction. AI: After intubation; VHR: After ventral hernia repair; END: End of surgery; SB: During spontaneous breathing through the endotracheal tube; 1 HR: One hour after extubation; APP: Abdominal perfusion pressure; MAP: Mean arterial pressure; IBP: Intrabladder pressure, IGP: Intragastric pressure; PaCO₂: Partial pressure of carbon dioxide in arterial blood; EtCO₂: End-tidal partial pressure of carbon dioxide.

Table 2 Agreement between the two techniques of intra-abdominal pressurе measurement

	Number of patients	Mean intra-abdominal pressure	Correlation analysis		Bland–Altman analysis
			r	P	bias	Precision
After tracheal intubation	29	7.83	0.65	0.002	-1.06	4
After ventral hernia repair	28	9.22	0.73	0.001	-0.57	2.8
At the end of surgery	26	8.91	0.75	0.001	-0.46	4.1
During spontaneous breathing through the end of tracheal tube (spontaneous breathing trial)	23	11.48	0.75	0.002	-0.19	3.6
At 1 h after tracheal extubation	27	9.7	0.81	0.001	-1.00	3.3

Table 3 Concordance between the two intra-abdominal pressure measurements during different study stages

	All measurements	AI	VHR	END	SB	1 HR
Number of measurements	133	29	28	26	23	27
Concordance correlation coefficient	0.74	0.61	0.84	0.62	0.81	0.69
95%CI	0.65-0.80	0.33-0.79	0.69-0.92	0.34-0.80	0.63-0.90	0.45-0.84
Precision	0.75	0.63	0.85	0.65	0.84	0.73
Accuracy	0.98	0.96	0.98	0.95	0.96	0.95

Precision: Pearson’s correlation coefficient; Accuracy: bias correction factor; AI: After intubation; VHR: After ventral hernia repair; END: End of surgery; SB: During spontaneous breathing through the endotracheal tube; 1 HR: One hour after extubation.