Table 2: Outcomes: The table shows both groups are similar in terms of procedural outcomes apart from oxygen flow (intervention) and lowest oxygen saturations measured during bronchoscopic procedures. This is not surprising as we expected that patients on lower flow of oxygen will have lower saturations during procedure. However, this didnít result in any more complications compared with the other group.

Characteristic

high flow,

N = 421

low flow,

N = 421

p-value2

Fentanyl dose (mg)

100 (75, 125)

100 (75, 125)

0.6

Midazolam dose (mg)

5.00 (4.00, 6.00)

5.00 (4.00, 6.00)

0.2

Need to reverse sedation

2 (4.8%)

1 (2.4%)

> 0.9

Flow rate at the start of the case (L/min)

 

 

< 0.001

2

0 (0%)

42 (100%)

 

25

42 (100%)

0 (0%)

 

Max flow rate (L/min)

25 (25, 25)

4 (2, 8)

< 0.001

Starting peripheral saturation (%)

 

 

0.6

95-100%

41 (98%)

39 (93%)

 

90-94%

1 (2.4%)

3 (7.1%)

 

Lowest peripheral saturation (%) (intraprocedure)

97.0 (96.0, 97.0)

92.0 (88.0, 95.0)

< 0.001

Duration of desaturations (min)

 

 

0.007

0

38 (90%)

25 (60%)

 

3

0 (0%)

1 (2.4%)

 

5

0 (0%)

5 (12%)

 

10

2 (4.8%)

3 (7.1%)

 

15

2 (4.8%)

3 (7.1%)

 

30

0 (0%)

4 (9.5%)

 

120

0 (0%)

1 (2.4%)

 

Post procedure hypoxia (SpO2

< 90%)

0 (0%)

1 (2.4%)

> 0.9

Bronchospasms

0 (0%)

1 (2.4%)

> 0.9

Hypotension

2 (4.8%)

0 (0%)

0.5

MERT calls

0 (0%)

0 (0%)

 

Pneumothorax

0 (0%)

0 (0%)

 

Respiratory failure

0 (0%)

0 (0%)

 

Patient comfort

 

 

0.3

Very comfortable

12 (29%)

8 (19%)

 

Comfortable

13 (31%)

20 (48%)

 

Slightly uncomfortable

11 (26%)

6 (14%)

 

Very uncomfortable

6 (14%)

8 (19%)

 

Sedation converted into general anaesthesia

0 (0%)

2 (4.8%)

0.5

Type 2 respiratory failure (Hypercapnic)

1 (2.4%)

0 (0%)

> 0.9

Unexpected admission to ward

1 (2.4%)

0 (0%)

> 0.9

1Median (IQR); n (%)

2Wilcoxon rank sum test; Fisher’s exact test; Pearson’s Chi-squared test