Although taking a radial pulse is considered to be an essential clinical skill, there have been few reports on how well it is measured in clinical practice, and how its accuracy and precision are influenced by rate, rhythm, and blood pressure.

This study is a retrospective quality audit carried out as part of a larger ongoing prospective observational trial. The radial pulse rates recorded by 2 research nurses were compared with the electrocardiogram (ECG) heart rates measured on acutely ill medical patients during their admission to a resource-poor hospital in sub-Saharan Africa.

There were 619 ECGs performed on 231 patients while they were in the hospital. The median interval between measuring the vital signs and obtaining an ECG was 12.6 minutes (mean 62.3, SD 104.3 minutes). The correlation coefficient between the pulse rate recorded and ECG heart rate was 0.54. The bias between the pulse rate and the ECG heart rate was 1.34, SD 13.51 beats per minute (ie, limits of agreement 26.5 beats per minute). Bias and variance were not influenced by blood and pulse pressure. However, tachycardia increased the variance and was the only independent predictor of a pulse deficit (odds ratio 2.32; 95% confidence interval, 1.53-3.51; chi-squared 17.21; P < .0001).

Practice-based evidence shows that in acutely ill patients, there is a poor correlation between the radial pulse and the ECG heart rate, and that tachycardia increases the variance and is the only independent predictor of a pulse deficit.