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Table 1 Subgroup analysis for study groups

From: Apnoeic oxygenation for emergency anaesthesia of pre-hospital trauma patients

Peri intubation phase 2 min pre to 2 min post intubation

 

Standard

Intervention

P value

Median SaO2 (IQR)

All patients

100 (96,100)

99 (96,100)

p = 0.0001

No hypoxia

100 (98,100)

100 (98,100)

p = 1.00

Mild Moderate hypoxia

94 (83,97.75)

94 (88,99)

p = 1.00

Severe hypoxia

79 (66.5,86)

83 (77,95)

p = 0.28

Total post intubation values / total 90 or less (% difference)

All patients

106/653 (16.2)

560/3659 (15.3)

0.546

No hypoxia

24/380 (6.3)

54/1492 (3.6)

0.02

Mild Moderate hypoxia

28/72 (38.9)

131/386 (33.9)

0.947

Severe hypoxia

41/51 (80.4)

118/177 (66.7)

0.195

Total post intubation values / total 85 or less (% difference)

All patients

65/653 (10.0)

340/3659 (9.3)

0.864

No hypoxia

7/380 (1.8)

20/1492 (1.3)

0.466

Mild Moderate hypoxia

11/71 (15.3)

61/386 (15.8)

0.947

Severe hypoxia

34/51 (66.7)

100/177 (56.5)

0.195

Post intubation phase (intubation - 10 min)

All patients

177/1464 (12.1)

959/8037 (11.9)

0.864

Total post intubation values / total 90 or less (% difference)

No hypoxia

43/1126 (3.8)

254/5928 (4.3)

0.476

Mild Moderate hypoxia

39/164 (23.8)

377/1424 (26.5)

0.458

Severe hypoxia

93/160 (58.1)

384/759 (50.6)

0.084

Recovery phase (2 min post intubation to 10 min post intubstion

All patients

139/1221 (11.4)

728/6396 (11.4)

0.998

Total post intubation values / total 90 or less (% difference)

No hypoxia

33/941 (3.5)

204/5121 (4.0)

0.488

Mild Moderate hypoxia

31/138 (22.5)

280/1128 (24.2)

0.544

Severe hypoxia

73/133 (54.9)

234/746 (31.4)

3.06E-07

Median SpO2 (IQR)

All patients

100 (96,100)

99 (96,100)

p = 0.0001

No hypoxia

100 (98,100)

100 (98,100)

p = 1.00

Mild Moderate hypoxia

94 (83,97.75)

94 (88,99)

p = 1.00

Severe hypoxia

79 (66.5,86)

83 (77,95)

p = 0.28

Total 90 or less / total peri intubation values (% difference)

All patients

106/653 (16.2)

560/3659 (15.3)

0.546

No hypoxia

24/380 (6.3)

54/1492 (3.6)

0.02

Mild Moderate hypoxia

28/72 (38.9)

131/386 (33.9)

0.947

Severe hypoxia

41/51 (80.4)

118/177 (66.7)

0.195

Total 85 or less / total peri intubation values (% difference)

All patients

65/653 (10.0)

340/3659 (9.3)

0.864

No hypoxia

7/380 (1.8)

20/1492 (1.3)

0.466

Mild Moderate hypoxia

11/71 (15.3)

61/386 (15.8)

0.947

Severe hypoxia

34/51 (66.7)

100/177 (56.5)

0.195

Post intubation phase (intubation - 10 min)

All patients

177/1464 (12.1)

959/8037 (11.9)

0.864

Total 90 or less / total post intubation values (% difference)

No hypoxia

43/1126 (3.8)

254/5928 (4.3)

0.476

Mild Moderate hypoxia

39/164 (23.8)

377/1424 (26.5)

0.458

Severe hypoxia

93/160 (58.1)

384/759 (50.6)

0.084

Recovery phase (2 min post intubation to 10 min post intubation)

All patients

139/1221 (11.4)

728/6396 (11.4)

0.998

Total 90 or less / total post intubation values (% difference)

No hypoxia

33/941 (3.5)

204/5121 (4.0)

0.488

Mild Moderate hypoxia

31/138 (22.5)

280/1128 (24.2)

0.544

Severe hypoxia

73/133 (54.9)

234/746 (31.4)

p < 0.0001

  1. Table 1 shows the 2 study groups (standard and intervention) subclassified by the degree of hypoxia was subclassified according to the pre-induction SpO2 value (taken at 0 min) as:
  2. • No hypoxia: SpO2 > 95%
  3. • Mild / moderate hypoxia: SpO2 85–95%
  4. • Severe hypoxia: SpO2 < 85%
  5. The median SpO2 is the median value of all values recorded for the all patients during the peri-intubation phase
  6. The categories reporting ‘total 90 or less’ and ‘total 85 or less’ refer to the number of patients who desaturated in the peri-intubation, post intubation, or recovery phase to an SpO2 or 90% or less, or 85% or less. This figure is reported as a proportion of the number of SpO2 values recorded for all patients in this group and subclassification