Effect of age on acute pain perception of a standardized stimulus in the emergency department

The study was undertaken to determine whether pain perception is different in elderly patients than in younger patients.

A cross-sectional, observational study was conducted at 2 urban academic emergency departments. Adult patients (> or =18 years of age) who required an 18-gauge intravenous catheter as part of their ED care were eligible. Patients were excluded for the following conditions: more than one attempt at intravenous catheter placement, altered mental status, visual impairment, intoxication, distracting pain, or abnormal upper extremities. Patients were asked to indicate on a 10-cm visual analog scale (VAS) the amount of pain they had at baseline immediately before intravenous catheter placement. They were then asked to indicate on a separate VAS the amount of pain caused by intravenous catheter placement. Patients aged 65 years and older were defined a priori as elderly.

Of 100 patients enrolled in the study, 32 (32%) were elderly. Elderly patients reported significantly less pain than nonelderly patients (Delta = -15 mm, 95% confidence interval -26 to -4 mm). Pain of intravenous catheter placement was not associated with sex, baseline pain, site of intravenous catheter insertion, or level of training of the individual placing the intravenous catheter.

Elderly patients experienced less acute pain than their younger counterparts in response to a standardized stimulus in a clinical setting. This difference is both statistically and clinically significant. This may have clinical implications for the assessment and treatment of acute pain in the elderly.