iGuyton

Venous return

Pmsa, Pvr and Eh, at the bedside.

CVP · MAP · Cardiac output · No inspiratory holds

Six values you already have give the mean systemic filling pressure analogue, the gradient for venous return and heart efficiency, with the Guyton diagram. Follow each patient over time and share a PDF report. Your cases stay on your device.

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CVP · CO Pmsa 0 4 8 12 −4 0 4 8 12 16 Right atrial pressure (mmHg) Flow (l/min)
Pmsa 14.5 mmHg Pvr 6.5 · Eh 0.45

Example: CVP 8, MAP 80 mmHg, CO 5 l/min, 60 years, 175 cm, 80 kg. The cardiac curve is schematic.

6bedside values you already have
3results: Pmsa, Pvr and Eh
10recent cases, each followed over time

Features

From the bedside to the report.

Built for intensive care, anaesthesia and cardiology, where venous return guides fluids, vasopressors and inotropes.

Bedside formula

Parkin and Leaning's method: results update while you type, with checks on impossible values.

Guyton diagram

Venous return line, Pmsa and the operating point drawn from your values. Tap to read each point.

Cases over time

Baseline, after fluids, after a vasopressor: every measurement of a case, with trends.

PDF report

Results, diagram, table of measurements, trends, method and reference, ready to print or share.

Method

A published, transparent formula.

Parkin WG, Leaning MS. Therapeutic control of the circulation. J Clin Monit Comput 2008;22:391–400 (PubMed).

BSA = 0.007184 · H0.725 · W0.425 (Du Bois)
c = 0.038 · (94.17 + 0.193·age) / (4.5 · 0.99age−15 · BSA)
Pmsa = 0.96·CVP + 0.04·MAP + c·CO
Pvr = Pmsa − CVP
Eh = Pvr / Pmsa    RVR = Pvr / CO

What you need

Central venous pressure at end-expiration; mean arterial pressure from the arterial line; cardiac output from your monitor or echocardiography; age, height and weight. The app's guide shows where each value comes from.

The demo

Try it now, free.

The web version is a demo: try the calculator and an example PDF report. Nothing is stored.

  1. Create an account

    Free, for healthcare professionals. Confirm your email with a link.

  2. Try the calculator

    Enter six values, read the Guyton diagram and create an example PDF.

  3. Get the app

    To keep your cases and follow them over time on iPhone, iPad or Android.

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