# Equations for CRT

 Static Compliance Alveolar minute ventilation Estimated 1ml per lb of ideal body weight for VD Cardiac Output Heart rate X stroke volume Mean arteriol pressure Mean: 90Monitors perfusionNormal:120/80 Cerebral Perfusion Pressure CPP=MAP-ICP Normal: 70-90 Smoking History Pack years= # of packs/day x # of years smoked 4 packs a day x 10 years equals 40 pack years ETT size Size= weight in kg divided by 10 Oral: 21-25 cm mark at lip Nasal: 26-29 cm mark Catheter size 8.0/2 =4x3 =12 french Alveolar air equation (FiO2 x 7) - (PaCO2 + 10) 50%= 300 torr100% O2= 600 torr The A-a Gradient (A-aDO2) A-aDO2 = PAO2 - PaO2 Arterial oxygen content (CaO2) CaO2 = (Hb x 1.34 x SaO2) + (PaO2 x .003) Normal: 17-20% Good PaO2, good Hb, Good SaO2 then answer is gonna be in high teens Bad PaO2, Bad Hb, Bad SaO2 then answer is gonna be in low teens Mixed venous oxygen content (CVO2) Bad arteriol CVO2 = (Hb x 1.34 x SVO2) + (PVO2 x .003) Normal: 14% Arteriol- Venous oxygen content difference C(a-V)O2 C(a-v)O2 = CaO2-CvO2 Normal:4-5% Shunt equation (Qs/Qt) Calculate the percent shunt when the A-aDO2 is 300 torr and the C(a-v)O2 is 3.6 vol %! For every 100 on the A-a gradient, add another 5% shunt to normal Answer is 20% Deadspace to tidal volume ratio (VD/VT) Duration of Flow Air to oxygen Ratio Total flow Total flow=(flow meter setting x factor) What is the total flow when a venti mask is set at 5 L/min and the dilution control is set at 28%? Air/O2 entrainment ratio is 10:1 for 28%Total flow factor is 11 5 x 11 = 55 L/min Raw (Peak pressure- Plateau pressure)/ flow L/sec Authordarrell2662 ID186403 Card SetEquations for CRT DescriptionEquations Updated2012-12-01T20:10:36Z Show Answers