SpO2 – Pulse Ox
Advantage: readings
Disadvantage: Inaccurate with poor perfusion or artifact
Terminate test if SpO2 is <%

Tidal Volume Vt
= VE / RR
Normal: ml per kg of body weight
At low/moderate workloads total ventilation will increase by increasing
At high workloads total ventilation increases by increasing

Frequency of Breathing
(# of accumulated breathes) / testing time in minutes = RR
Normal at rest: –

Minute Ventilation
Vt x RR = Ve

Normal Resting: – L/min
Normal Exercising: – L/min
Maximum minute ventilation = FEV1 x
Should be able to reach % of max
If max minute ventilation is this indicates a primary ventilator limitation to exercise.

Alveolar Minute Ventilation
= (Vt-) x or = VE – (VD x RR)
Estimated anatomical deadspace is ml per lb of body weight

O2 Consumption – (VO2) Amount of O2 in L/min
Normal at Rest: L/min
Normal Exercising: Up to L/min
Requires inline gas analyzers to measure O2%, an FeCO2 and a spirometer

O2 Pulse
Volume of O2 consumer per
(VO2/HR) x = mL O2/beat
Normal Resting: – mL O2/beat
Normal Exercising: – mL O2/beat
Significance: O2 pulse that doesn’t increase with high HR indicates disease
Tachycardia at rest will O2 pulse
Arrhythmia will O2 pulse
Beta Blockers will O2 pulse
Plateau in O2 consumption will O2 pulse

CO2 Production (VCO2) – Amount of CO2 in L/min
Normal resting: L/min
Normal exercising: Up to l/min
Gives indication of status
FeCO2 x = VCO2

PH
pH will decrease due to increased and acid
In normal patients, pH will not decrease until is reached.

Alveolar-Arterial O2 Tension, A-a Gradient, PAO2-PaO2 or P(A-a)O2
PaO2 < means you should terminate the tes
Normal P(A-a)O2
On RA: -
On 100% O2: Less than
Increase in P(A-a)O2 with in PaO2: Increased right to left , mismatch, defects
Use Supplemental O2 if at rest.

Ventilatory Equivalent for O2 (Ve/VO2)
Relationship of Ve to performed (VO2)
Gives indication of of gas exchange at different workloads
(BTPS)/(STPD)
Normal at rest and low/moderate workloads: – L/LVO2
Increase in Ve out of proportion to in VO2 means disease
Increase in Ve/VO2 at rest means

Ventilatory Equivalent for CO2 (Ve/VCO2)
Relationship of Ve to
(BTPS)/(STPD)
Normal: - L/LCO2
Can be used to determine maximum tolerable workloads for patients with disease
Anaerobic threshold reached when Ve/VCO2 is constant but Ve/VO2

PaCO2/ETCO2
Used to calculate
Normal VD/Vt = - at rest
with exercise
Moderate Workloads: PaCO2 is constant, increases
High Workloads: Metabolic due to lactic acid production

Respiratory Exchange Ratio (RER)
Relationship of O2 consumption and CO2 production at the mouth which represents gas exchange in the lungs
RER = / or (FeCO2xVe)/VO2
Normal at rest:
Normal with Exercise: or greater
RER should at anaerobic threshold

Hemodynamics
Cardiac Monitor – Simplest way to monitor heart rate and rhythm.
Normal HR: –

Blood Pressure:
Equipment: Indwelling catheter and pressure transducer
You can also take BP
Normal Values:
Systolic:
Diastolic:
Mean:
MAP = (2x + )/3
Heart spends twice as much time in .

Central Venous Pressure (CVP)
Used to Monitor systemic drainage and function of the heart.
Catheter is located in .
Normal: - mmHG or - cmH2O
CVP – AKA:
Right Pressure
R Atriral filling pressue
side preload
Right ventricular pressure
ventricular end pressure

Pulmonary Artery pressure (PAP)
PAP and PCWP are measure with tipped directed pulmonary artery catheter (Swan Ganz)
Catheter is directed through the side of the heart and positioned in
Normal PAP:
Systolic: mmHg
Diastolic: mmHg
Mean: mmHg
Mixed samples should be drawn from pulmonary artery.
If blood is bright red the balloon was or wedged if PaCO2 = PaO2

Pulmonary Capillary Wedge Pressure (PCWP)
When balloon is it will measure PCWP
Normal = mmHg (4-12)
Estimates pulmonary drainage back to heart
PCWP aka:
atrial pressure
Left atrial pressure
Left side preload
ventricular filling pressure
Left end diastolic pressure

Cardiac Output (Qt)
Output of left to systemic circulation
Normal Qt is L/min (4-8) depending on body size
Fick equation: Qt = /(C(a-v)O2x )
If stroke volume is known: Qt= x
Thermal Dilution: Cold saline injection
Cardiac Index = /() Normal: – lpm/m2

CVP: ↑ ↑ PAP: N ↓ PCWP: N ↓ QT: N = Heart Failure, Pulmonale, Valve Stenosis

CVP: ↑ PAP: ↑↑ PCWP: N ↓ QT: N = Disorders, Pulm , HTN, Air

CVP: N PAP: ↑ PCWP: ↑↑ QT:↓ = heart Failure, valve stenosis, , High effects

CVP: ↑↑ PAP: ↑ PCWP: ↑ QT: ↑ =
CVP: ↓↓ PAP: ↓ PCWP: ↓ QT: ↓ =

Systemic Vascular resistance (SVR) : Pressure gradient across circulation divided by
SVR = ( – ) / Qt
Normal: < mmHg/l/min or 1600 Dynes/sec
SVR is with systemic hypertension or vasoconstriction

Pulmonary Vascular Resistance (PVR): Pressure gradient across circulation divided by Qt
PVR = ( – ) / Qt
Normal: < mmHg/L/mi or 200 Dynes/sec
PVR is increased with , HTN, disease

Metabolic Measurements
-by-breath measurement
Determines measurements of VO2, VCO2, RR, Vt
Requires use of one way valve, and continuous sampling of gases.

Mixing Chamber
Pt inspires room air via 1 way valve then exhales into gas mixing chamber with to completely mix the gases
and concentration are measured.