Echocardiographic detection of transpulmonary bubble transit during acute respiratory distress syndrome

Annals of Intensive Care

Table 1 Clinical and respiratory characteristics of patients with acute respiratory distress syndrome according to transpulmonary bubble transit

	Transpulmonary bubble transit
	Absent-or-minor ( n = 159)	Moderate-to-large ( n = 57)	p value
Age, years	62 ± 17	61 ± 18	0.81
Male gender, n (%)	110 (69%)	40 (70%)	0.89
McCabe and Jackson class^a			0.72
0	99 (62%)	34 (60%)
1	39 (25%)	13 (23%)
2	21 (13%)	10 (18%)
SAPS II at ICU admission	55 ± 23	54 ± 25	0.66
Cause of lung injury, n (%)			0.80
Pneumonia	84 (53%)	34 (60%)
Aspiration	40 (25%)	11 (19%)
Non-pulmonary sepsis	14 (9%)	5 (9%)
Other causes	21 (13%)	7 (12%)
Berlin category^b			0.34
Moderate ARDS	91 (58%)	36 (64%)
Severe ARDS	66 (42%)	20 (36%)
Cirrhosis	4 (3%)	4 (7%)	0.12
Respiratory settings^b
Tidal volume, mL/kg	6.5 ± 1.0	6.1 ± 0.8	0.03
Minute ventilation	10.7 ± 2.2	10.6 ± 2.7	0.80
Respiratory rate, bpm	26 ± 4	27 ± 6	0.41
PEEP, cm H₂O	9 ± 4	9 ± 3	0.68
Plateau pressure, cmH₂O	24 ± 5	25 ± 5	0.70
Compliance, mL/cmH₂O	32 ± 13	29 ± 11	0.20
Driving pressure, cmH₂O	15 ± 5	15 ± 5	0.35
Arterial blood gases^c
PaO₂/FiO₂ ratio, mmHg	120 ± 56	125 ± 56	0.53
FiO2 (%)	85 ± 19	80 ± 21	0.14
PaO_2, mmHg	99 ± 42	96 ± 40	0.66
Oxygenation Index	19 ± 10	19 ± 13	0.59
PaCO₂, mmHg	43 ± 12	46 ± 14	0.21
pH	7.32 ± 0.12	7.33 ± 0.12	0.50
Lactate, mmol/L	2.3 ± 2.8	2.2 ± 2.1	0.87
Septic shock	105 (66%)	46 (81%)	0.04

ARDS, acute respiratory distress syndrome; ^a[44]; ^brespiratory settings and criteria for Berlin definition were recorded at the time of transesophageal echocardiography; PEEP, positive end-expiratory pressure; ^cblood gases were recorded on the day of transesophageal echocardiography (latest available before echocardiography) and the proportion of patients receiving nitric oxide on that day was similar in the group with moderate-to-large TPBT compared to absent-or-minor group (11 [19%] vs. 22 [14%], p = 0.34).