J Clin Med Res

Journal of Clinical Medicine Research, ISSN 1918-3003 print, 1918-3011 online, Open Access

Article copyright, the authors; Journal compilation copyright, J Clin Med Res and Elmer Press Inc

Journal website http://www.jocmr.org

Original Article

Volume 7, Number 9, September 2015, pages 700-705

Comparison of Energy Expenditure and Oxygen Consumption of Spontaneous Breathing Trial Conducted With and Without Automatic Tube Compensation

Figure 2. Box plot of VO₂, EE, VCO₂, and RQ at baseline, with and without ATC. The diamonds are atypical values (outliers).

**Table 1.** Study Participants Demographics
Variables	Values
SD: standard deviation; APACHE II: Acute Physiology and Chronic Health Evaluation II; SAPS 3: Simplified Acute Physiology Score 3; ICU: intensive care unit; MV: mechanical ventilation; ETT: endotracheal tube or tracheostomy; ARF: acute respiratory failure; COPD: chronic obstructive pulmonary disease.
Gender
Male, n (%)	18 (51)
Female, n (%)	17 (49)
Age (years) (mean ± SD)	61.4 ± 16.1
APACHE II (mean ± SD)	24.6 ± 8.4
SAPS 3 (mean ± SD)	67.7 ± 22
ICU mortality, n (%)	6 (15)
Hospital mortality, n (%)	17 (42.5)
Length of ICU stay (mean ± SD)	14.1 ± 8.2
Length of hospital stay (mean ± SD)	78 ± 70.71
Airway resistance at baseline (cm H₂O/L/s)	9.02 ± 2.35
ETT size (mm)	7.85 ± 0.49
Reason to initiate MV
ARF, n (%)	24 (68%)
Septic shock, n (%)	7 (20%)
COPD, n (%)	2 (6%)
Hepatic encephalopathy, n (%)	1 (3%)
Cerebrovascular accident, n (%)	1 (3%)
Cause of ARF
Pneumonia, n (%)	11 (46%)
Post-operative, n (%)	7 (29%)
Acute pulmonary edema, n (%)	3 (12.5%)
Sepsis, n (%)	2 (8.4%)
Cardiac arrest, n (%)	1 (4.1%)
Diagnosis upon admission
Septic shock, n (%)	11 (31%)
Respiratory, n (%)	11 (31%)
Post-operative, n (%)	9 (26%)
Cerebrovascular accident, n (%)	1 (3%)
Others, n (%)	3 (9)

Table 1. Study Participants Demographics

Variables

Values

SD: standard deviation; APACHE II: Acute Physiology and Chronic Health Evaluation II; SAPS 3: Simplified Acute Physiology Score 3; ICU: intensive care unit; MV: mechanical ventilation; ETT: endotracheal tube or tracheostomy; ARF: acute respiratory failure; COPD: chronic obstructive pulmonary disease.

Gender

Male, n (%)

18 (51)

Female, n (%)

17 (49)

Age (years) (mean ± SD)

61.4 ± 16.1

APACHE II (mean ± SD)

24.6 ± 8.4

SAPS 3 (mean ± SD)

67.7 ± 22

ICU mortality, n (%)

6 (15)

Hospital mortality, n (%)

17 (42.5)

Length of ICU stay (mean ± SD)

14.1 ± 8.2

Length of hospital stay (mean ± SD)

78 ± 70.71

Airway resistance at baseline (cm H₂O/L/s)

9.02 ± 2.35

ETT size (mm)

7.85 ± 0.49

Reason to initiate MV

ARF, n (%)

24 (68%)

Septic shock, n (%)

7 (20%)

COPD, n (%)

2 (6%)

Hepatic encephalopathy, n (%)

1 (3%)

Cerebrovascular accident, n (%)

1 (3%)

Cause of ARF

Pneumonia, n (%)

11 (46%)

Post-operative, n (%)

7 (29%)

Acute pulmonary edema, n (%)

3 (12.5%)

Sepsis, n (%)

2 (8.4%)

Cardiac arrest, n (%)

1 (4.1%)

Diagnosis upon admission

Septic shock, n (%)

11 (31%)

Respiratory, n (%)

11 (31%)

Post-operative, n (%)

9 (26%)

Cerebrovascular accident, n (%)

1 (3%)

Others, n (%)

3 (9)

**Table 2.** Estimated Values for the Differences of T1 and T2, G1 and G2, and P1 and P2
Variables	Estimated value T1-T2	95% confidence interval	P value	Estimated value G1-G2	95% confidence interval	P value	Estimated value P1-P2	95% confidence interval	P value
T1: treatment 1 with ATC; T2: treatment 2 without ATC; G1: group 1; G2: group 2; P1: period 1; P2: period 2; VO₂: oxygen consumption; EE: energy expenditure; VCO₂: carbon dioxide production; RQ: respiratory quotient; Vt: tidal volume; Rr: respiratory rate; RSBI: rapid shallow breathing index; P0.1: airway occlusion pressure 100 ms after onset of inspiratory flow; HR: heart rate; MAP: mean arterial pressure; SPO₂: peripheral oxygen saturation.
VO₂ (mL/kg/min)	-1.6	-4.36 to 1.07	0.23	5.4	-26.44 to 37.43	0.73	-3.5	-6.25 to -0.82	0.01
EE (kcal/day)	-5.4	-21.67 to 10.79	0.500	34.0	-163.79 to 231.93	0.728	-22.8	-39.04 to -6.58	0.007
VCO₂ (mL/kg/min)	0.3	-2.49 to 3.11	0.82	2.1	-15.30 to 19.64	0.82	1.0	-3.86 to 1.74	0.45
RQ	0.004	-0.01 to 0.02	0.63	-0.007	-0.11 to 0.09	0.88	0.023	0 to 0.04	0.02
Peak pressure (cm H₂O)	2.00	1.39 to 2.62	0.0001	0.55	-0.93 to 2.03	0.4555	0.35	-0.25 to 0.97	0.2446
Vt (mL)	13.32	-30.65 to 57.30	0.5415	24.20	-89.14 to 137.56	0.6668	17.27	-26.70 to 61.24	0.4296
Rr (bpm)	0.34	-0.87 to 1.56	0.5688	1.26	-2.49 to 5.02	0.4993	-0.76	-1.98 to 0.44	0.2080
RSBI (bpm/L)	1.17	-4.11 to 6.46	0.6531	8.99	-28.32 to 46.31	0.6268	-3.77	-9.06 to 1.51	0.1558
P0.1 (cm H₂O)	-0.49	-0.84 to -0.14	0.0073	0.14	-1.21 to 1.50	0.8276	-0.39	-0.75 to -0.04	0.0279
HR (beats per min)	-1.84	-3.65 to -0.048	0.0445	-1.38	-9.25 to 12.02	0.7921	-1.41	-3.22 to 12.02	0.1176
MAP (mm Hg)	-0.57	-3.14 to 2.00	0.6526	-7.74	-16.89 to 1.40	0.0942	0.57	-16.89 to 1.40	0.6510
SpO₂ (%)	-0.11	-0.64 to 0.41	0.6644	-0.63	-1.98 to 0.71	0.3416	0.26	-0.27 to 0.79	0.3235

Table 2. Estimated Values for the Differences of T1 and T2, G1 and G2, and P1 and P2

Variables

Estimated value T1-T2

95% confidence interval

P value

Estimated value G1-G2

95% confidence interval

P value

Estimated value P1-P2

95% confidence interval

P value

T1: treatment 1 with ATC; T2: treatment 2 without ATC; G1: group 1; G2: group 2; P1: period 1; P2: period 2; VO₂: oxygen consumption; EE: energy expenditure; VCO₂: carbon dioxide production; RQ: respiratory quotient; Vt: tidal volume; Rr: respiratory rate; RSBI: rapid shallow breathing index; P0.1: airway occlusion pressure 100 ms after onset of inspiratory flow; HR: heart rate; MAP: mean arterial pressure; SPO₂: peripheral oxygen saturation.

VO₂ (mL/kg/min)

-1.6

-4.36 to 1.07

0.23

5.4

-26.44 to 37.43

0.73

-3.5

-6.25 to -0.82

0.01

EE (kcal/day)

-5.4

-21.67 to 10.79

0.500

34.0

-163.79 to 231.93

0.728

-22.8

-39.04 to -6.58

0.007

VCO₂ (mL/kg/min)

0.3

-2.49 to 3.11

0.82

2.1

-15.30 to 19.64

0.82

1.0

-3.86 to 1.74

0.45

0.004

-0.01 to 0.02

0.63

-0.007

-0.11 to 0.09

0.88

0.023

0 to 0.04

0.02

Peak pressure (cm H₂O)

2.00

1.39 to 2.62

0.0001

0.55

-0.93 to 2.03

0.4555

0.35

-0.25 to 0.97

0.2446

Vt (mL)

13.32

-30.65 to 57.30

0.5415

24.20

-89.14 to 137.56

0.6668

17.27

-26.70 to 61.24

0.4296

Rr (bpm)

0.34

-0.87 to 1.56

0.5688

1.26

-2.49 to 5.02

0.4993

-0.76

-1.98 to 0.44

0.2080

RSBI (bpm/L)

1.17

-4.11 to 6.46

0.6531

8.99

-28.32 to 46.31

0.6268

-3.77

-9.06 to 1.51

0.1558

P0.1 (cm H₂O)

-0.49

-0.84 to -0.14

0.0073

0.14

-1.21 to 1.50

0.8276

-0.39

-0.75 to -0.04

0.0279

HR (beats per min)

-1.84

-3.65 to -0.048

0.0445

-1.38

-9.25 to 12.02

0.7921

-1.41

-3.22 to 12.02

0.1176

MAP (mm Hg)

-0.57

-3.14 to 2.00

0.6526

-7.74

-16.89 to 1.40

0.0942

0.57

-16.89 to 1.40

0.6510

SpO₂ (%)

-0.11

-0.64 to 0.41

0.6644

-0.63

-1.98 to 0.71

0.3416

0.26

-0.27 to 0.79

0.3235