Table 5 Differences of discarding different volumes blood sample in the arterial heparin blood collector subgroup analysis by age

Age<50 (N = 11)

PH

7.4036 ± 0.0516

7.4136 ± 0.0568

7.4173 ± 0.0694

0.219

0.255

0.506

PaO2

(mmHg)

244.8182 ± 123.5539

232.0909 ± 68.4878

229.2727 ± 95.2146

0.142

0.247

0.720

PCO2

(mmHg)

39.0909 ± 5.4855

39.7273 ± 8.0011

39.1818 ± 9.2176

0.490

0.947

0.548

K⁺

(mmol/L)

3.2909 ± 0.1921

3.3455 ± 0.2583

3.3727 ± 0.2533

0.311

0.260

0.695

Na⁺

(mmol/L)

140.2727 ± 4.3149

141.6364 ± 2.1574

141.2727 ± 2.1490

0.211

0.357

0.397

THbc (g/HL)

10.7091 ± 1.4775

11.4000 ± 1.5881

11.3182 ± 1.6351

0.014^*#

0.002^**#

0.683

Age

50–60 (N = 21)

PH

7.3848 ± 0.0685

7.3914 ± 0.0762

7.3910 ± 0.0784

0.079

0.114

0.853

PaO2

(mmHg)

255.1429 ± 90.2958

239.7143 ± 77.3603

238.5714 ± 76.9029

0.084

0.124

0.887

PCO2

(mmHg)

41.6667 ± 8.4459

42.8095 ± 7.8951

43.9524 ± 8.0962

0.079

0.009^**#

0.023^*

K⁺

(mmol/L)

3.2238 ± 0.4335

3.3429 ± 0.3932

3.4286 ± 0.3594

0.007^**#

0.000^**#

0.000^**#

Na⁺

(mmol/L)

141.6667 ± 2.8694

142.2381 ± 2.4881

142.2381 ± 2.4679

0.253

0.208

1.000

THbc (g/HL)

10.2476 ± 1.3052

10.7667 ± 1.2338

11.0857 ± 1.2097

0.002^**#

0.000^**#

0.013^*#

Age>60 (N = 22)

PH

7.3668 ± 0.0470

7.3723 ± 0.0487

7.3664 ± 0.0440

0.076

0.888

0.029^*

PaO2

(mmHg)

229.6364 ± 93.1223

224.7273 ± 96.0487

222.1364 ± 96.2497

0.430

0.271

0.651

PCO2

(mmHg)

43.7727 ± 6.5968

45.6818 ± 6.1905

46.5000 ± 5.5869

0.001^**#

0.000^**#

0.068

K⁺

(mmol/L)

3.1818 ± 0.5058

3.4045 ± 0.4530

3.4818 ± 0.4697

0.001^**#

0.000^**#

0.000^**#

Na⁺

(mmol/L)

141.5445 ± 2.7208

141.5000 ± 2.2414

141.7273 ± 2.2293

0.905

0.598

0.261

THbc (g/HL)

10.1091 ± 1.4342

10.7091 ± 1.3082

11.0864 ± 1.2590

0.000^**#

0.000^**#

0.000^**#