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

Figure 1 Changes in inintra-abdominal pressure in ventral hernia repair: both methods of measurement are presented. ^aP < 0.05 vs after tracheal intubation (AI) values using Wilcoxon’s signed-rank test with Bonferroni correction. Box plots present median, interquartile interval, and minimum–maximum. VHR: After ventral hernia repair; END: End of surgery; SB: During spontaneous breathing through the endotracheal tube; 1 HR: One hour after extubation; IBP: Intrabladder pressure; IGP: Intragastric pressure.

Figure 2 Changes in arterial to end-tidal CO₂ gradient (A) and oxygenation index (PaO₂/FiO₂) (B) during and after ventral hernia repair. ^aP < 0.05 vs after tracheal intubation (AI), Wilcoxon’s signed-rank test. Box plots present median, interquartile interval, and minimum-maximum. VHR: After ventral hernia repair; END: End of surgery; SB: During spontaneous breathing through the endotracheal tube; 1 HR: One hour after extubation.

Figure 3 Regression analysis of intrabladder and intragastric pressure. Patient averages (n = 30) with mean ± SD deviation of intrabladder pressur (IBP) and intragastric pressure (IGP).

Figure 4 Bland-Altman analysis of all paired measurements (n = 128, A) and of paired measurements of mean intrabladder pressure and mean intragastric pressure (n = 30, B). IBP: Intrabladder pressure; IGP: Intragastric pressure; IBPm: Mean intrabladder pressure; IGPm: Mean Intragastric pressure.

Figure 5 Four quadrants trend plot. Plot for 117 paired measurements of ΔIBP and ΔIGP. From the 117 initial paired measurements, 55 pairs were excluded because either ΔIBP or ΔIGP were ≤± 2.5 mmHg or because ΔIBP or ΔIGP was equal to zero (exclusion zone). The calculated level of concordance was 94.9%. See text for explanation. IBP: Intrabladder pressure; IGP: Intragastric pressure.