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Table 1 Baseline characteristics

From: Breath-holding as a novel approach to risk stratification in COVID-19

Characteristic

COVID-19 patients

Controls

(N = 23)

All

(N = 50)

VS + 

(N = 11)

VS − 

(N = 39)

Population factors

    

 Age, years

59.6 ± 13.6

62.7 ± 7.5

58.8 ± 15.0

45.4 ± 10.6

 Female sex, n (%)

8 (16)

0 (0.0)

8 (20.5)

14 (60.9)

 Body mass index, kg/m2

26.4 ± 4.0

28.1 ± 4.2

25.9 ± 3.4

25.2 ± 4.7

 Caucasian or white race/ethnicity, n (%)

44 (88)

10 (90.9)

34 (87.2)

19 (82.6)

History

    

 History of hypertension, n (%)

26 (52)

9 (81.8)

17 (43.6)

1 (4.3)

 History of cardiovascular disease, n (%)

4 (8)

1 (9.1)

3 (7.7)

0 (0.0)

 History of diabetes, n (%)

8 (16)

2 (18.2)

6 (15.4)

0 (0.0)

 Current smoking, n (%)

6 (12)

3 (27.3)

3 (7.7)

0 (0.0)

Current medications

    

β-blockers, n (%)

4 (8)

1 (9.1)

3 (7.7)

0 (0.0)

ACE-inhibitors, n (%)

9 (18)

4 (36.4)

5 (12.2)

0 (0.0)

ARB, n (%)

4 (8)

2 (18.2)

2 (5.1)

0 (0.0)

Clinical presentation at admission

    

Baseline SpO2, %

94.5 ± 4.6

89.9 ± 6.6

95.8 ± 2.3

97.6 ± 1.0

PaO2 at admission, mmHg*

76.2 ± 15.3

71.0 ± 16.4

77.7 ± 14.9

–

PaCO2 at admission, mmHg*

36.4 ± 5.4

37.0 ± 4.6

36.2 ± 6.0

–

Baseline Heart rate, beats/min

86.8 ± 16.8

86.2 ± 21.0

86.9 ± 13.6

–

Baseline systolic blood pressure, mmHg

127.3 ± 19.1

126.5 ± 18.8

127.5 ± 19.8

–

Baseline diastolic blood pressure, mmHg

78.5 ± 10.8

74.4 ± 12.5

79.7 ± 10.2

–

Anosmia, n (%)

11 (22.0)

1 (9.1)

10 (25.6)

–

Ageusia, n (%)

12 (24.0)

2 (18.2)

10 (25.6)

–

Gastrointestinal symptoms, n (%)

13 (26.0)

2 (18.2)

11 (28.2)

–

Dyspnea presence, n (%)

13 (26.0)

3 (27.3)

10 (25.6)

–

Laboratory tests

 C-reactive protein, mg/L

20.2 ± 41.9

14.6 ± 23.7

21.8 ± 15.0

–

 D-dimer, μg/L

0.8 ± 0.8

1.1 ± 0.8

0.7 ± 0.9

–

Breath-holding measurements

 Mean desaturation, %

2.34 ± 1.78

4.42 ± 2.37

2.21 ± 1.43

1.57 ± 1.24

 Maximal breath-hold duration**, s

46.8 ± 16.9

51.8 ± 12.7

41.8 ± 14.2

53.0 ± 20.3

 Recovery breath, %baseline

188.9 ± 61.3

184.6 ± 81.8

195.0 ± 62.1

180.5 ± 49.4

Outcomes

 Discharge:oxygen:ventilatory support, n

14:36:11

0:11:11

14:25:0

–

 Duration of hospitalization, days

29.8 ± 17.2

47.4 ± 12.5

24.8 ± 15.3

–

  1. Data are expressed as mean ± SD or as N (%). Patients who met the criteria for the adverse primary composite outcome are denoted “VS + ” (N = 4 non-invasive bi-level pressure support, N = 7 intensive care, N = 1 death). In all patients, diagnosis was confirmed with a positive nasal or pharyngeal swab. All patients admitted to ICU were administered mechanical ventilatory support; the patient who died was also in intensive care on mechanical ventilatory support. “VS − “ indicates patients discharged without meeting adverse primary outcome criteria. Average time to the primary outcome in VS + patients was 6  [2] days (median [IQR]). Non-Caucasian/Non-White race/ethnicities were black (1 VS + and 1 VS − COVID-19 patients), Hispanic (3 VS + COVID-19 patients) and Asian (1 VS − COVID-19 patient and 4 controls). Note that participants included in the table are those who provided data for all breath-holding measures. “Discharge” indicates discharge without oxygen or interventions that met criteria for the primary outcome during the hospital stay. On average, 3.8 ± 1.0 20-s breath-holds per individual were analyzed to calculate the ventilatory response variable (3.6 ± 0.9 in controls); 1.6 ± 0.6 maximal breath-holds were used to determine maximal breath-hold duration (2.1 ± 0.5 in controls); 5.2 ± 1.1 breath-holds (20-s or maximal) were used to calculate mean desaturation (6.3 ± 1.1 in controls). *Data available for 42 patients (9 VS + and 33 VS −). Abbreviations: SpO2, peripheral oxyhemoglobin saturation; PaO2, partial pressure of oxygen; PaCO2, partial pressure of carbon dioxide; ACE, angiotensin converting enzyme; ARB, angiotensin II receptor blockers. **Data shown are adjusted for baseline SpO2 and mean desaturation (regression)
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Critical Care

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