This shows you the differences between two versions of the page.
Both sides previous revisionPrevious revisionNext revision | Previous revision | ||
resources:formulae [2024/01/02 13:44] – [Table] admin | resources:formulae [2024/06/05 17:46] (current) – [Equation of Motion] admin | ||
---|---|---|---|
Line 10: | Line 10: | ||
^ Alveolar Gas Equation | ^ Alveolar Gas Equation | ||
^ Mech Power, VC | ${MP}_{VC} = 0.098 \cdot RR \cdot V_t[PIP-\frac{1}{2}(P_{plat}-PEEP)]$ | ^ Mech Power, VC | ${MP}_{VC} = 0.098 \cdot RR \cdot V_t[PIP-\frac{1}{2}(P_{plat}-PEEP)]$ | ||
- | ^ Mech Power, PC | ${MP}_{VC} = 0.098 \cdot RR \cdot V_t[PEEP + \Delta P_{insp}(1-\exp{\frac{-T_{insp}}{RC}})]$ | + | ^ Mech Power, PC | ${MP}_{VC} = 0.098 \cdot RR \cdot V_t[PEEP + \Delta P_{insp}(1-e^{\frac{-T_{insp}}{RC}})]$ |
===== Respiratory Equations ===== | ===== Respiratory Equations ===== | ||
==== Mechanical Power ==== | ==== Mechanical Power ==== | ||
- | ${MP}_{VC} = 0.098 \cdot RR \cdot V_t[PIP-\frac{1}{2}(P_{plat}-PEEP)] \approx \frac{VE(P_{peak}+PEEP+\frac{Q_{insp}}{6})}{20}$ | + | === Volume Control === |
+ | ${MP}_{VC} = 0.098 \cdot RR \cdot V_t[PIP-\frac{1}{2}(P_{plat}-PEEP)] \approx \frac{MV(P_{peak}+PEEP+\frac{Q_{insp}}{6})}{20}$ | ||
+ | ===Pressure Control === | ||
+ | ${MP}_{VC} = 0.098 \cdot RR \cdot V_t[PEEP + \Delta P_{insp}(1-\exp(\frac{-T_{insp}}{RC}))]$ | ||
+ | |||
+ | ${MP}_{VC} = 0.098 \cdot RR \cdot V_t[PEEP + \Delta P_{insp}(1-e^{\frac{-T_{insp}}{RC}})] \approx 0.098 \cdot RR \cdot V_t(PEEP + \Delta P_{insp})$ | ||
* [[https:// | * [[https:// | ||
Line 27: | Line 32: | ||
+ | ==== Shunt Equation (Berggren Equation)==== | ||
+ | $$\frac{Q_s}{Q_t} = \frac{C_{C_{O_2}} - C_{a_{O_2}}}{C_{C_{O_2}} - C_{v_{O_2}}}$$ | ||
+ | |||
+ | where: | ||
+ | * $Q_s=$ pulmonary physiology shunt $(\frac{mL}{min})$ | ||
+ | * $Q_t=$ cardiac output $(\frac{mL}{min})$ | ||
+ | * $C_{C_{O_2}} = $ end-pulmonary-capillary oxygen content | ||
+ | * $C_{a_{O_2}} = $ arterial oxygen content | ||
+ | * $C_{v_{O_2}} =$ mixed venous oxygen content | ||
+ | |||
+ | So, you will need an ABG and a true mixed VBG (art line + SGC). | ||
+ | |||
+ | === Derivation === | ||
==== Dead Space Fraction ==== | ==== Dead Space Fraction ==== | ||
$\frac{V_D}{V_T} = \frac{P_ACO_2 - P_ECO_2}{P_ACO_2}$ | $\frac{V_D}{V_T} = \frac{P_ACO_2 - P_ECO_2}{P_ACO_2}$ | ||
Line 72: | Line 90: | ||
$P_{aw} = \dot VR + \frac{V_t}{C} + PEEP_{total} + P_{musc}$ | $P_{aw} = \dot VR + \frac{V_t}{C} + PEEP_{total} + P_{musc}$ | ||
+ | ==== CPET Testing==== | ||
+ | ===Heart rate reserve | ||
+ | $HRR = HR_{achieved}^{max} - HR_{predicted}^{peak}$, | ||
+ | |||
+ | where $HR_{predicted}^{peak} = 220 - age$ | ||
+ | |||
+ | ===Slope of work efficiency=== | ||
+ | $m(work_e) = \frac{\Delta VO_2}{\Delta WR}$ | ||
+ | |||
+ | ===Slope of heart rate rise=== | ||
+ | $\frac{\Delta HR}{\Delta VO_2}$ | ||
===== CARDS ===== | ===== CARDS ===== | ||
$TPG = mPAP - PCWP$ | $TPG = mPAP - PCWP$ |