Accuracy of weight and height estimation in an intensive care unit: Implications for clinical practice and research*

Abstract

Objective: 

Numerous calculations routinely used in the intensive care require the knowledge of patients’ weight and height, although these measurements are not always made. Estimates by doctors or nurses are often substituted. This study sought to ascertain the accuracy of estimates of weight and height of patients made by intensive care unit (ICU) staff.

Design: 

Prospective clinical study.

Setting: 

Sixteen-bed mixed medical and surgical ICU in a university teaching hospital.

Patients: 

Fourteen patients had their height and weight estimated by 20 members of the medical and nursing staff.

Measurements: 

After all estimates had been recorded, measurements of weight and height were obtained. Weight was measured by means of a patient hoist with a calibrated weighing facility and height using a steel tape measure.

Main Results: 

Estimation of weight was poor, with 47% of estimates at least 10% different and 19% of estimates at least 20% different from the measured values. The majority of height estimates were within 10% of the measured values.

Conclusions: 

Individual estimates of weight and height are frequently inaccurate. These errors of estimation could compromise application of effective therapies, as well as contribute to a reduction in design sensitivity of clinical trials.