Table 1.
Characteristics of Patients and Main Results
| SUPINE RESPONDERS | SUPINE NON-RESPONDERS | |||||
|---|---|---|---|---|---|---|
| Baseline characteristics | ||||||
| No (%) | 14 (50) | 14 (50) | ||||
| Age, median (IQR) | 66 (56–72) | 66 (57–69) | ||||
| Sex, No (%) | ||||||
| Women | 1 (7.1) | 5 (35.7) | ||||
| Men | 13 (92.9) | 9 (64.3) | ||||
| BMI, median (IQR) | 27.5 (24.2–30.0) | 28.3 (27.5–31.1) | ||||
| Current smokers, No (%) | 1 (7) | 0 (0) | ||||
| Arterial hypertension, No (%) | 7 (50) | 9 (64) | ||||
| Type 2 Diabetes Mellitus, No (%) | 1 (7) | 4 (29) | ||||
| SOFA score, median (IQR) | 3 (3–3) | 3 (2–3) | ||||
| Disease course, median (IQR) | ||||||
| Days from diagnosis of infection | 11.5(8–14) | 9.5 (8–12) | ||||
| Days from hospital admission | 3.5 (2–7) | 3.5 (2–6) | ||||
| Days from respiratory support | 2.5 (1–5) | 2 (1–4) | ||||
| Ventilatory settings | ||||||
| HCPAP, No (%) | 11 (79) | 11 (79) | ||||
| HFNC, No (%) | 3 (21) | 3 (21) | ||||
| FiO2, median (IQR) | 0.5 (0.5–0.6) | 0.5 (0.5–0.5) | ||||
| PEEP (if HCPAP), median (IQR) | 10 (10–12) | 10 (10–12) | ||||
| Flow (if HFNC), median (IQR) | 40 (35–40) | 35 (35–40) | ||||
| Protocol | Seated | Supine | Prone | Seated | Supine | Prone |
|---|---|---|---|---|---|---|
| Starting decubitus, no (%) | 2 (14) | 6 (43) | 6 (43) | 4 (29) | 5 (36) | 5 (36) |
| Respiratory variables, median (IQR) | ||||||
| PaO2, mmHg | 82.2 (73.2–101) | 120 (108–149)* | 139 (108–184)* | 96 (67–117) | 92 (74–120) | 102 (68.5–125)* |
| PaO2/FiO2 ratio | 152 (133–177) | 224 (186–248)* | 278 (198–336)* | 192 (160–224) | 186 (165–230) | 204 (150–246) |
| PaCO2, mmHg | 38 (35.9–39) | 39.1 (38–43)* | 37.8 (37–41)* | 38.3 (34.1–40) | 40.5 (35.8–42)* | 39.8 (36–41) |
| Arterial pH | 7.45 (7.44 -7.46) | 7.43 (7.43 -7.45)* | 7.44 (7.44 -7.46) | 7.46 (7.44 -7.47) | 7.45 (7.42 -7.47)* | 7.44 (7.43 -7.46) |
| Respiratory rate, bpm | 19 (17–22) | 17 (15–18)* | 19 (16–23)* | 21.5 (18–24) | 19 (16–22)* | 18.5 (16–21) |
| Subjective variables | ||||||
| Borg dyspnea scale, median (IQR) | 0 (0–0) | 0 (0–0) | 0 (0–0) | 0 (0–0) | 0 (0–0) | 0 (0–1) |
| Discomfort, no (%) | 2 (14.3) | 1 (7.1) | 8 (57.1)* | 0 (0) | 0 (0) | 5 (35.7)* |
| Hemodynamics, median (IQR) | ||||||
| Cardiac index, L/min/m2 a | 3 (3–3.2) | 3.1 (3–3.3) | 3.3 (3.3–3.5)* | 2.8 (2.5–3.5) | 2.9 (2.4–3.1) | 3.1 (3–3.4)* |
| Stroke volume index, mL/m2 a | 41 (39–42) | 47 (38–48)* | 46 (40–52) | 39 (33–45) | 50 (37–55)* | 40 (37–51) |
| Pulse pressure, mmHg | 51 (42–58) | 55 (47–60)* | 54 (48–70) | 55 (46–78) | 69 (53–90)* | 71 (56- 81) |
| Heart rate, bpm | 70 (69–77) | 64 (60–71)* | 68 (60–77)* | 75 (67–86) | 70 (60–76)* | 76 (69–82)* |
IQR, interquartile range; BMI, body mass index (weight in kilograms divided by the square of the height in meters); SOFA, sequential organ failure assessment; HCPAP, helmet continuous positive airway pressure; HFNC, high flow nasal cannula; FiO2, fraction of inspired oxygen; PEEP, positive end expiratory pressure; PaO2, partial pressure of oxygen; mmHg, millimeters of mercury; PaCO2, partial pressure of carbon dioxide; bpm, breaths (or beats) per minute
aData available from 12 patients (5 supine responders and 7 supine non-responders) equipped with non-invasive advanced hemodynamic monitoring (CNAP®). Note that changes in stroke volume are paralleled by changes in pulse pressure (its surrogate) confirming the trend of cardiac output even in patients without advanced hemodynamic monitoring
*Significantly different (p < 0.05) with respect to the preceding decubitus in the table