How do you calculate pulmonary vascular resistance in wood?

Pulmonary vascular resistance (PVR = [TPG]/ CO, in Wood units = mm Hg/L/min, customary unit. Multiply by 80 to convert to dynes⋅sec⋅cm-5): Gold standard for estimation of the severity of pre-capillary pulmonary HTN. Cardiac output, Fick equation (COf, in L/min): VO2/ [(SaO2 – SvO2) x Hb x 13.4)].

How do you calculate pulmonary vascular resistance?

PVR can be calculated by subtracting the left atrial pressure from the mean pulmonary artery pressure (PAP), divided by the cardiac output (CO) and multiplied by 80.

How are woods units calculated?

Pulmonary calculations As an example: If Systolic pressure: 120 mmHg, Diastolic pressure: 80 mmHg, Right atrial mean pressure: 3 mmHg, Cardiac output: 5 L/min, Then Mean Arterial Pressure would be: (2 Diastolic pressure + Systolic pressure)/3 = 93.3 mmHg, and Systemic vascular resistance: (93 – 3) / 5 = 18 Wood Units.

How is TPG calculated?


  1. TPG = mPAP − PAWP. (1a)
  2. DPG = dPAP − PAWP = 0.62mPAP − PAWP. (1b) The TPG and DPG dependence on CO:
  3. TPG = PVR ∗ CO. (2a)
  4. DPG = 0.62PVR ∗ CO − 0.38PAWP. (2b)

What are woods units?

Wood units. A simplified measurement of pulmonary vascular resistance that uses pressures instead of more complicated units measured by subtracting pulmonary capillary wedge pressure from the mean pulmonary arterial pressure and dividing by cardiac output in liters per minute.

How does echo calculate pulmonary vascular resistance?

ECHO: PVR were calculated by 2 methods: 1) by using the tricuspid regurgitation velocity (TRV) and the time velocity integral (TVI) of the right ventricular outflow tract and calculating PVR as follows: PVR=TRV/TVI x 10+0.16 (Abbas A.

What is normal TPG?

Yet the initial TPG was, on average, >12 mmHg, with a range of values from 6–20 mmHg.

What does wood units measure?

The cord is a unit of measure of dry volume used to measure firewood and pulpwood in the United States and Canada. A cord is the amount of wood that, when “racked and well stowed” (arranged so pieces are aligned, parallel, touching and compact), occupies a volume of 128 cubic feet (3.62 m3).

What is normal PVR in woods units?


Haemodynamic variable Method of measurement
PVR Wood units and PVRI Wood units·m−2 Calculated using: PVR=(mPAP–mean PAWP)/cardiac output PVRI=PVR/BSA
RAP mmHg Tracings to measure pressure waveforms
RVP mmHg Tracings to measure pressure waveforms
SVR Wood units Calculated using: SVR=(mSAP–RAP)/cardiac output

What are wood units?

What is the normal systemic vascular resistance?

Systemic vascular resistance (SVR) This is a calculated value that reflects the resistance the blood meets across the entire systemic circulation from the starting point in the aorta to the end point in the right atrium (related to left ventricle afterload). Normal range for SVR is between 700 and 1600 dynes-sec/cm5.

What is normal pressure for pulmonary artery?

Normal mean pulmonary-artery pressure (PAP) is approximately 14 mmHg at rest. In the patient with Pulmonary Hypertension, the mean blood pressure, measured by special tests at the main pulmonary artery within the heart, is greater than 25 mmHg at rest or 30 mmHg during exercise.

The pulmonary vascular resistance can be calculated in units of dyn·s·cm−5 as. where the pressures are measured in units of millimetres of mercury (mmHg) and the cardiac output is measured in units of litres per minute (L/min).

What is the normal range for pulmonary artery systolic pressure?

Normal pulmonary artery pressure is 8-20 mm Hg at rest. If the pressure in the pulmonary artery is greater than 25 mm Hg at rest or 30 mmHg during physical activity, it is abnormally high and is called pulmonary hypertension.