Tierärztliche Hochschule Hannover Vergleichende Studie zur

Publikation 2
gases, respectively. The samples were placed on ice and analysed within 10 min of
collection. Blood gas analysis included measurement of blood pH, partial pressure of
oxygen (pO 2 ) and carbon dioxide (pCO 2 ), base excess (BE) as well as oxygen
saturation (S a O 2 ) using an automated blood gas analyser (Rapidlab 348, Bayer
Diagnostics) after prior adjustment for blood temperature and haemoglobin
concentration (Celltax MEK-6108G, Nihon-Kohdan, Rosbach, Germany).
Calculations
Cardiopulmonary parameters were calculated using the following standard equations:
• stroke volume (SV) [mL beat -1 ]: SV= (CO/HR) × 1000 (Amory et al. 1992)
• systemic vascular resistance (SVR) [dynes×s×cm -5 ]: SVR= ((MAP –
CVP)/CO) × 79.9
• pulmonary vascular resistance (PVR) [dynes×s×cm -5 ]: PVR = ((MPAP –
PCWP)/CO) × 79.9 (Amory et al. 1992)
• tidal volume (V T ) [L]: V T = Minute Ventilation (V E )/ RR, whereby V E was
determined by the minute volumeter.
• arterial and venous oxygen content were calculated according to (Wilson et al.
1988) and (Sprung et al. 1983):
o arterial oxygen content (C a O 2 ) [mL dL -1 ]: C a O 2 = [Hb] × S a O 2 × 1.36 + (p a O 2
× 0.003),
o mixed venous oxygen content (C v¯ O 2 ) [mL dL -1 ]: (C v¯ O 2 )= [Hb] × S v¯ O 2 ×
1.36 + (p v¯ O 2 × 0.003)
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