Bland-Altman analysis (Radial artery SV-Dorsalis pedis artery SV) Bias: −12.0, Precision: ± 13.28

Bland-Altman analysis (Radial artery SVV-Dorsalis pedis artery SVV) Bias: 0.94, Precision: ± 3.84

Correlation of Radial artery SV with Dorsalis pedis artery SV Y = 1.35X-10.4, r = 0.76, n = 14,893, **** : p<0.0001

Correlation of Radial artery SVV with Dorsalis pedis artery SVV Y = 0.52X + 3.73, r = 0.51, n = 14,248, ****: p<0.0001

The connected components of the RED system frame include a halo device anchored to the cranium, a vertical midline facial bar, and a horizontal bar pulled to the maxilla with transcutaneous extranasal wires or intraoral wires.

The patients with the RED system were ventilated using a facemask for children. The facemask for children was rotated through 90° and was positioned over the mouth; the nostrils were occluded by an assistant.

The patients with the RED system were ventilated using a facemask for infants. The facemask for infants was positioned over the nose; the mouth was occluded by an assistant.