The pressure-assisted mode with spontaneous diaphragm contraction should therefore be used as soon as possible.
Multinomial logistic regression, using a stepwise approach, was then performed with the entire cohort for mode of delivery, with spontaneous vaginal delivery (SVD) acting as the reference category.
The mean age of the study group was 73 ± 10 years; 11 of them were female and mean APACHE II score was 19 ± 6. RSBI did not differ significantly between spontaneous mode and other combinations, but the best correlation with spontaneous mode was found with PS 5 PEEP:0 (P = 0.0001, r = 0.719), and the worst with PS 0 PEEP:5 combination.
One must choose between spontaneous breathing modes with partial ventilatory support, or controlled modes; either a pressure-controlled mode in which tidal volume is the dependent variable, or a volume-controlled mode in which peak pressure may vary.
The risk for TV to be greater than 6 ml/kg IBW was significantly increased with spontaneous breaths assisted by PSV modes (for PSV OR 19.36; [12.37–30.65]) and significantly reduced in APRV (OR 0.44; [0.26–0.72]) and PSV with guaranteed volume mode.
Women who planned a vaginal birth included all other women with spontaneous, augmented or induced labour, regardless of eventual mode of delivery.
However, we did not use other ventilation modes with decelerating flows nor simulate irregular respiratory cycles as can be seen with spontaneous breathing in some patients.
However, Heenen and coworkers [ 23] demonstrated the limitations of pulse pressure variability when they studied 21 patients with spontaneous breathing through a mask or on pressure support mode.
The subjects were 21 critically ill patients with spontaneous breathing movements receiving mechanical ventilation with pressure support mode (n = 9) or breathing through a face mask (n = 12), and who required a fluid challenge.
For women with spontaneous labour, pre-pregnancy BMI was not a significant risk factor for mode of delivery, controlling for covariates.
