Effects of different positive end-expiratory pressure titration strategies during prone positioning in patients with acute respiratory distress syndrome: a prospective interventional study

Table 2 Gas exchange and hemodynamics using three different PEEP titration strategies during supine and prone positioning

	PEEP_ARDSNetwork		PEEP_Estat,RS		PEEP_Ptpexp		p values
	Supine	Prone	Supine	Prone	Supine	Prone	Positioning effect	PEEP strategy effect	Positioning and PEEP strategy interaction
PaO₂/FiO₂ (mm Hg)	136 ± 36	228 ± 86*	170 ± 72	237 ± 91*	192 ± 76	240 ± 100*	< 0.001	< 0.001	< 0.001
PaCO₂ (mm Hg)	57.0 ± 10.5	57.9 ± 10.5	57.6 ± 10.3	57.7 ± 10.7	57.6 ± 10.4	58.0 ± 10.4	0.346	0.308	0.297
pHa	7.3 ± 0.1	7.3 ± 0.1	7.3 ± 0.1	7.3 ± 0.1	7.3 ± 0.1	7.3 ± 0.1	0.812	0.070	0.101
HR (beats/min)	92.6 ± 19.1	93.1 ± 21.2	92.8 ± 20.5	93.2 ± 21.4	92.6 ± 19.2	92.4 ± 20.6	0.903	0.603	0.711
MAP (mm Hg)	83.0 ± 10.8	87.1 ± 11.2*	82.6 ± 9.8	89.5 ± 11.9*	79.2 ± 11.3	87.6 ± 11.4*	< 0.001	0.009	0.011
Norepinephrine (µg/kg/min)	0.2 ± 0.3	0.2 ± 0.3	0.2 ± 0.3	0.2 ± 0.3	0.2 ± 0.2	0.2 ± 0.2	0.182	0.458	0.756
CVP (mm Hg)	14.1 ± 6.4	16.8 ± 5.6*	15.1 ± 6.9	16.8 ± 6.2	16.4 ± 7.4	17.5 ± 6.8	0.068	< 0.001	< 0.001
S_cvO₂ (%)	75.3 ± 7.4	81.2 ± 6.8	77.6 ± 5.2	82.8 ± 6.2	77.6 ± 6.1	81.4 ± 6.3	< 0.001	0.002	0.046
CI (L/min/m²)	3.7 ± 1.0	3.7 ± 0.9	3.5 ± 0.9	3.7 ± 1.0*	3.2 ± 0.7	3.6 ± 0.8*	0.004	< 0.001	< 0.001

Values are means ± standard deviation of 40 patients with moderate to severe ARDS. Two-way repeated measures ANOVA was used to compare the effects of different PEEP titration strategies on gas exchange and hemodynamic parameters during supine and prone positioning (p < 0.05)
Bold numbers represent statistically significant differences between groups
CI cardiac index, CVP central venous pressure, HR heart rate, MAP mean arterial pressure, PaCO₂ arterial partial pressure of carbon dioxide, PEEP positive end-expiratory pressure, PEEP_ARDSNetwork PEEP titrated according to the ARDS Network lower PEEP table, PEEP_Estat,RS PEEP titrated according to the lowest elastance of the respiratory system, PEEP_Ptpexp PEEP titrated according to end-expiratory transpulmonary pressure, PaO₂/FiO₂ arterial oxygen partial pressure divided by the fraction of inspired oxygen, pHa negative logarithm of the molar concentration of dissolved hydronium ions in arterial blood, S_cvO₂ central venous oxygen saturation
*Significant differences at each PEEP titration strategy between supine and prone positioning

ISSN: 1364-8535