Table 3.
Clinical and respiratory characteristics of patients with acute respiratory distress syndrome according to transpulmonary bubble transit (subgroup analysis)
| Transpulmonary bubble transit | ||||
|---|---|---|---|---|
| Absent to minor | Moderate | Large | ||
| ( n = 159) | ( n = 42) | ( n = 15) | p value | |
| Age, years | 63 (53 to 76) | 64 (48 to 74) | 72 (53 to 78) | 0.64 |
| Male gender, n (%) | 110 (69.2%) | 30 (71.4%) | 10 (66.7%) | 0.93 |
| McCabe and Jackson class* | 0.12 | |||
| 0 | 99 (62.3%) | 29 (69%) | 5 (33.3%) | |
| 1 | 39 (24.5%) | 8 (19%) | 5 (33.3%) | |
| 2 | 21 (13.2%) | 5 (11.9%) | 5 (33.3%) | |
| SAPS II at ICU admission | 55 (38 to 69) | 45 (32 to 66) | 69 (47 to 81) | 0.15 |
| Cause of lung injury, n (%) | 0.67 | |||
| Pneumonia | 84 (52.8%) | 23 (54.8%) | 11 (73.3%) | |
| Aspiration | 40 (25.2%) | 10 (23.8%) | 1 (6.7%) | |
| Non-pulmonary sepsis | 14 (8.8%) | 3 (7.1%) | 2 (13.3%) | |
| Other causes | 21 (13.2%) | 6 (14.3%) | 1 (6.7%) | 0.59 |
| Berlin category | ||||
| Moderate ARDS | 91 (58.0%) | 26 (61.9%) | 10 (71.4%) | |
| Severe ARDS | 66 (42.0%) | 16 (38.1%) | 4 (28.6%) | |
| Cirrhosis | 4 (2.5%) | 1 (2.4%) | 3 (20.0%)a,b | 0.003 |
| Respiratory settings# | ||||
| Tidal volume, mL/kg | 6.3 (6.0 to 7.0) | 6.1 (5.7 to 6.6) | 6.1 (5.9 to 6.6) | 0.06 |
| Minute ventilation | 10.6 (9.0 to 12.0) | 10.5 (8.7 to 12.2) | 10.0 (9.1 to 12.8) | 0.95 |
| Respiratory rate, bpm | 25 (23 to 30) | 28 (24 to 30) | 25 (22 to 30) | 0.46 |
| PEEP, cmH2O | 10 (5 to 12) | 10 (7 to 10) | 9 (5 to 12) | 0.86 |
| Plateau pressure, cmH2O | 25 (21 to 28) | 24 (20 to 27) | 28 (24 to 28) | 0.26 |
| Compliance, mL/cmH2O | 30 (22 to 38) | 28 (21 to 39) | 25 (20 to 30) | 0.27 |
| Driving pressure, cmH2O | 15 (11 to 18) | 14 (11 to 19) | 17 (15 to 20) | 0.14 |
| Arterial blood gases$ | ||||
| PaO2/FiO2 ratio, mmHg | 112 (81 to 150) | 115 (77 to 161) | 132 (100 to 162) | 0.46 |
| FiO2 (%) | 100 (70 to 100) | 80 (60 to 100) | 80 (60 to 100) | 0.33 |
| PaO2, mmHg | 89 (70 to 116) | 87 (69 to 103) | 92 (75 to 158) | 0.44 |
| PaCO2, mmHg | 41 (36 to 48) | 44 (39 to 51)a | 36 (33 to 46)b | 0.02 |
| pH | 7.33 (7.24 to 7.40) | 7.34 (7.29 to 7.41) | 7.35 (7.28 to 7.40) | 0.79 |
| Lactate, mmol/L | 1.3 (0.9 to 2.7) | 1.4 (0.8 to 2.3) | 1.8 (0.8 to 3.1) | 0.87 |
ARDS, acute respiratory distress syndrome; *44; #respiratory settings were recorded at the time of transesophageal echocardiography; PEEP, positive end-expiratory pressure; $blood gases were recorded on the day of transesophageal echocardiography (latest available before echocardiography) and the proportion of patients receiving nitric oxide and prone position on the TEE day was similar in the groups with large, moderate, or absent to minor TPBT (2 [13.3%] vs. 9 [21.4%] vs. 22 [13.9%], p = 0.48; and 1 [6.7%] vs. 7 [16.7%] vs. 22 [13.8%], p = 0.63, respectively); a p value <0.05 (corrected Mann-Whitney test after Kruskal-Wallis test) as compared to absent to minor transpulmonary bubble transit; b P value <0.05 (corrected Mann-Whitney test after Kruskal-Wallis test) as compared to moderate transpulmonary bubble transit.