Ireton Jones Equation Calculator

Ireton-Jones Equations

The Ireton Jones equations adjust for changes in metabolic demand due to mechanical ventilation in burns patients, with special provision for the hypercatabolic state of trauma and burns.

Spontaneously Breathing

• IJEE = 629 - 11 x A + 25 x W - 609 x O

Ventilator-dependent

• 1992 version IJEE = 1925 - 10(A) + 5(W) +281 (G) +292 (T) +851 (B)
• 2002 version (revised 1997 equation) IJEE = 1784 - 11(A)+ 5(W)+244 (G) + 239(T) + 804(B)

Where: A = age in years, W = weight in kg, G = gender (1 for male, 0 for female), O = obesity, T = trauma, B = burns (1 for present, 0 for absent)

In the original study of 1992, the correlation between height, age, gender, weight, ventilatory status and diagnosis and measured energy expenditures of hospitalized patients was tested.

Multivariate regression analysis was applied on a sample of 200 patients and the above equations were derived. The equations were subsequently tested on 100 patients. Measured energy expenditures were not significantly different from those calculated via the equations (paired t test, p greater than 0.25).

In 1997, a new analysis was performed on the data from the 1992 study to evaluate whether the discrepancy between the measured energy expenditure and the 1992 Ireton-Jones equation could be minimized. Following statistical analysis of 99 ventilator-dependent patients, the 1992 equation was improved, with the new equation found to provide more accurate estimates in 59% of the studied population. The rate of EE overestimation decreased from 65% to 52% in the new equation.

References

Original reference

Ireton-Jones CA, Turner WW, Liepa GU, Baxter CR. Equations for the estimation of energy expenditures in patients with burns with special reference to ventilatory status. J Burn Care Rehabil 1992; 13(3):330-333.

Ireton-Jones C, Jones JD. Improved equations for predicting energy expenditure in patients: The Ireton-Jones equations. Nutr Clin Pract. 2002; 17:29-31.

Other references

Kross EK et al. A Comparison of Predictive Equations of Energy Expenditure and Measured Energy Expenditure in Critically Ill Patients. J Crit Care. 2012; 27(3): 321.e5–321.e12.

Walker RN, Heuberger RA. Predictive Equations for Energy Needs for the Critically Ill. Respir Care 2009; 54(4):509:521.

Fraipont V, Preiser JC. Energy Estimation and Measurement in Critically Ill Patients. Journal of Parenteral and Enteral Nutrition 37.6 (2013): 705-713.