Appendix.

Formulas Used to Calculate Variables

Variable	Formula
CI (mL/kg per minute)	$$\frac{\text{CO\hspace{0.17em}}(\text{L}/\text{min})}{\text{BW\hspace{0.17em}}(\text{kg})}\times 1000$$
SV (mL/beat)	$$\frac{\text{CO\hspace{0.17em}}(\text{L}/\text{min})}{\text{HR\hspace{0.17em}}(\text{beats}/\text{min})}\times 1000$$
SVI (mL/beat per kilogram)	$$\frac{\text{SV\hspace{0.17em}}(\text{mL}/\text{beat})}{\text{BW\hspace{0.17em}}(\text{kg})}$$
SVV (%)	$$\frac{{\text{SV}}_{\text{max}}\hspace{0.17em}(\text{mL}/\text{beat})-{\text{SV}}_{\text{min}}\hspace{0.17em}(\text{mL}/\text{beat})}{{\text{SV}}_{\text{mean}}\hspace{0.17em}(\text{mL}/\text{beat})}$$
SVR (dynes · s/cm5)	$$\frac{\text{MAP\hspace{0.17em}}(\text{mm}\hspace{0.17em}\text{Hg})-\text{CVP\hspace{0.17em}}(\text{mm\hspace{0.17em}Hg})}{\text{CO\hspace{0.17em}}(\text{L}/\text{min})}\times 80$$
SVRI (dynes · s/cm5 per kilogram)	$$\frac{\text{MAP\hspace{0.17em}}(\text{mm\hspace{0.17em}Hg})-\text{CVP\hspace{0.17em}}(\text{mm\hspace{0.17em}Hg})}{\text{CO\hspace{0.17em}}(\text{L}/\text{min})}\times 80÷\text{BW\hspace{0.17em}}(\text{kg})$$
CaO2 (mL/dL)	$$[\text{Hb\hspace{0.17em}}(\text{g}/\text{L})\times {\text{SaO}}_2\hspace{0.17em}(\%)\times 1.34]+0.0031\times {\text{PaO}}_2$$
CcvO2 (mL/dL)	$$[\text{Hb\hspace{0.17em}}(\text{g}/\text{L})\times {\text{ScvO}}_2\hspace{0.17em}(\%)\times 1.34]+0.0031\times {\text{PcvO}}_2$$
VO2 (mL O2/kg per minute)	$$\frac{({\text{CaO}}_2\times {\text{CcvO}}_2)\times \text{Cl}}{100}$$
DO2 (mL O2/kg per minute)	$$\frac{{\text{CaO}}_2\times \text{Cl}}{100}$$
ERO2 (%)	$$\frac{({\text{VO}}_2)}{({\text{DO}}_2)}\times 100$$

CI — Cardiac index; CO — Cardiac output; BW — Bodyweight; SV — Stroke volume; HR — Heart rate; SVI — Stroke volume index; SVV — Stroke volume variation; SVR — Systemic vascular resistance; CVP — Central-venous pressure; SVRI — Systemic vascular resistance index; MAP — Mean arterial pressure; CaO₂ — Arterial oxygen content; Hb — Hemoglobin; SaO₂ — Saturation of hemoglobin in arterial blood; PaO₂ — Arterial partial pressure of oxygen; CcvO₂ — Central-venous oxygen content; PcvO₂ — Central-venous partial pressure of oxygen; ScvO₂ — Saturation of hemoglobin in central-venous blood; VO₂ — oxygen consumption; DO₂ — oxygen delivery; ERO₂ — oxygen extraction ratio.