Cardiac Power Index: Clinical Guide

Overview

Calculates cardiac power indexed to body surface area from mean arterial pressure and cardiac index.

Clinical Significance

Cardiac power index integrates pressure generation and indexed flow. Low values can indicate severe pump failure but are not diagnostic alone.

When to Use

• Use when the stated clinical calculation is relevant to the patient and decision being considered.
• Use contemporaneous measurements obtained with appropriate technique.
• Confirm that the equation and units match local practice before acting on the result.

How It Is Calculated

• Cardiac power index = MAP × cardiac index ÷ 451.

Interpretation

• Cardiac power index integrates pressure generation and indexed flow. Low values can indicate severe pump failure but are not diagnostic alone.
• Interpret trends and the full clinical picture rather than relying on a single calculated value.

Worked Example

Enter a valid set of the required measurements. MedicalC applies: Cardiac power index = MAP × cardiac index ÷ 451. The displayed result should then be checked against the clinical context and local guidance.

Patient Considerations

• Consider whether physiology, treatment or sampling conditions changed between measurements.
• Consider whether the patient differs from the population in which the equation is normally used.

Limitations

• The result is only as reliable as the entered measurements and assumptions behind the equation.
• The calculator does not replace clinical assessment, definitive measurement or specialist advice.
• Thresholds and interpretation may vary between populations, laboratories and clinical pathways.

Clinical Pearls

• Confirm units before calculation.
• Use values obtained at the same clinical time point.
• Document the component measurements with the calculated result.

Common Mistakes

• Mixing SI and conventional units.
• Using estimated or non-contemporaneous measurements without acknowledging uncertainty.
• Treating a calculated value as a diagnosis or treatment instruction.

Evidence Base

The implemented equation follows the established published or guideline-based relationship: Cardiac power index = MAP × cardiac index ÷ 451.

References

1. Fincke R, et al. Cardiac power is the strongest haemodynamic correlate of mortality in cardiogenic shock. JACC. 2004. — Primary publication, guideline or established physiologic source supporting the equation.