Inspiratory effort impacts the accuracy of pulse pressure variations for fluid responsiveness prediction in mechanically ventilated patients with spontaneous breathing activity: a prospective cohort study

Chen, Hui; Liang, Meihao; He, Yuanchao; Teboul, Jean-Louis; Sun, Qin; Xie, Jianfen; Yang, Yi; Qiu, Haibo; Liu, Ling

doi:10.1186/s13613-023-01167-0

Annals of Intensive Care

Table 1 Baseline characteristics of included patients at enrollment stratified by the median value of P_0.1 and ΔP_occ

From: Inspiratory effort impacts the accuracy of pulse pressure variations for fluid responsiveness prediction in mechanically ventilated patients with spontaneous breathing activity: a prospective cohort study

	Stratified by P_0.1			Stratified by ΔP_occ
	P_0.1 < 1.5 cmH₂O	P_0.1 ≥ 1.5 cmH₂O	P value	ΔP_occ < − 9.8 cmH₂O	ΔP_occ ≥ − 9.8 cmH₂O	P value
Number	90	99	–	93	96	–
Age, year	66.8 (12.8)	66.0 (13.9)	0.69	67.5 (13.9)	65.2 (12.7)	0.23
Gender, male (%)	51 (56.7)	70 (70.7)	0.063	66 (71.0)	55 (57.3)	0.071
BMI, kg/m²	23.8 (3.6)	23.7 (4.1)	0.79	24.1 (4.3)	23.5 (3.3)	0.31
APACHE II	25.0 (6.3)	24.0 (6.3)	0.26	23.4 (6.0)	25.5 (6.4)	0.020
SOFA score	9.7 (3.3)	10.0 (3.7)	0.58	9.8 (3.4)	9.9 (3.6)	0.75
Acute circulatory failure origin, n (%)
Septic shock	78 (86.7)	89 (89.9)	0.64	83 (89.2)	84 (87.5)	0.88
Cardiogenic shock	1 (1.1)	3 (3.0)	0.68	4 (4.3)	0 (0.0)	0.12
Neurogenic shock	6 (6.7)	6 (6.1)	1.0	2 (2.2)	10 (10.4)	0.042
Hypovolemic shock	5 (5.6)	5 (5.1)	1.0	5 (5.4)	5 (5.2)	1.0
Respiratory parameters at enrollment
FiO₂	0.50 (0.18)	0.48 (0.17)	0.31	0.47 (0.16)	0.50 (0.19)	0.27
Tidal volume, ml	429.8 (96.4)	420.7 (87.5)	0.50	423.52 (80.68)	426.50 (101.70)	0.82
Tidal volume/PBW, ml/kg	7.2 (1.0)	6.8 (1.0)	0.002	6.9 (1.0)	7.1 (1.00)	0.041
Respiratory rate (Set), bpm	15.0 (2.3)	15.4 (2.6)	0.25	15.3 (2.4)	15.1 (2.5)	0.54
Respiratory rate (Observed), bpm	17.7 (3.3)	20.9 (6.2)	< 0.001	20.9 (6.1)	17.9 (3.8)	< 0.001
Peak pressure, cmH₂O	23.8 (5.4)	25.2 (7.1)	0.21	24.8 (5.7)	24.1 (6.6)	0.53
Plateau pressure, cmH₂O	17.5 (4.0)	18.0 (5.3)	0.054	18.2 (5.2)	17.3 (4.2)	0.20
Driving pressure, cmH₂O	11.6 (4.1)	11.9 (5.0)	0.72	12.1 (4.9)	11.5 (4.2)	0.38
Compliance, ml/cmH₂O	38.7 [30.0, 50.7]	35.3 [27.9, 47.1]	0.46	33.6 [27.9, 46.3]	39.0 [31.3, 51.8]	0.13
PEEP, cmH₂O	5.0 (0.0)	5.1 (0.7)	0.24	5.1 (0.7)	5.0 (0.0)	0.21
P_0.1, cmH₂O	0.7 [0.2, 1.0]	2.8 [1.9, 5.0]	< 0.001	2.3 [1.5, 5.0]	0.8 [0.3, 1.6]	< 0.001
ΔP_occ, cmH₂O	− 3.6 [− 7.4, − 2.0]	− 13.4 [− 22.1, − 8.9]	< 0.001	− 14.6 [− 23.1, − 10.7]	-3.7 [-5.9, -2.0]	< 0.001
PaO₂/FiO₂, mmHg	223 [164, 287]	223 [177, 287]	0.88	225 [201, 290]	220 [159, 268]	0.19
Hemodynamic parameters at enrollment
Heart rate, beats/min	98.2 (21.7)	98.5 (19.4)	0.91	96.1 (18.2)	90.0 (15.2)	0.013
HR/RR	5.15 (1.06)	4.90 (1.37)	0.16	4.85 (1.27)	5.18 (1.17)	0.065
Vasopressor dose, μg/kg/min NEE	0.32 [0.15, 0.50]	0.37 [0.16, 0.57]	0.20	0.37 [0.15, 0.57]	0.31 [0.16, 0.58]	0.43
Lactate, mmol/L	3.4 (2.7)	3.5 (2.6)	0.83	3.2 (2.6)	3.6 (2.7)	0.28
Fluid responders	22 (24.4)	31 (31.3)	0.37	32 (34.4)	21 (21.9)	0.079

BMI Body mass index, APACHE II Acute physiology and chronic health score II, SOFA Sequential organ failure assessment, PBW Predicted body weight, PEEP Positive end-expiratory pressure, P_0.1 Airway occlusion pressure, ΔP_occ Airway pressure swing during a whole breath occlusion, PaO₂/FiO₂ Arterial partial pressure of oxygen/fraction of inspired oxygen, HR/RR Heart Rate/Respiratory Rate (Observed), NEE Norepinephrine equivalent

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