To the Editor:
We are frequently asked which arm should be used to measure blood pressure in patients with hemiplegia. We have observed that blood pressure measurements from the hemiplegic arms of post-stroke patients do not correlate well with measurements from the nonhemiplegic arm. The following two cases illustrate that finding. Patient 1 is a 69-yr-old male who suffered a stroke 2 yr prior to sustaining a femoral neck fracture. Residuals from the stroke included mild dementia and right hemiparesis with spasticity. The blood pressure in the hemiparetic arm was 114/68 mm Hg, whereas the blood pressure in the nonparetic arm was 157/73 mm Hg. The radial pulse was also weaker in the paretic arm than the nonparetic arm. Patient 2 is a 75-yr-old male who presented for colon resection. He had suffered a stroke with residual right hemiparesis 2 yr prior to the current surgery. Blood pressure was 100/60 mm Hg in the paretic arm and 150/74 mm Hg in the nonparetic arm. Yagi et al.  measured blood pressure, both noninvasively and invasively, in 47 patients after stroke. They found that blood pressure was significantly higher in the paretic arm than in the nonparetic arm. Panayiotou et al.  measured blood pressure in 15 patients with acute hemiparesis and flaccidity and found the systolic and diastolic blood pressures to be higher in the paretic arm in 8 of 15 patients and lower in 7 of the 15 patients. Dewar et al.  measured blood pressure in 103 hemiplegic patients and found blood pressure in the paretic arm to be higher if it was spastic and lower if it was flaccid. They concluded that muscle tone influences extremity blood pressure. A number of investigators, including Broe and Ofner , have described vasomotor changes affecting the upper extremities in patients after a stroke. These changes may affect the paretic arm, the nonparetic arm, or both.
We measured blood pressure in 14 patients with hemiplegia. Nine patients had spasticity on the affected side and five had flaccidity. All five of the patients with flaccid arms had lower blood pressure in the flaccid arm compared with the normal arm. Five of the nine patients with spasticity had higher blood pressure in the paretic arm, four had lower blood pressure in the paretic arm, and one patient had equal blood pressures. Two patients in whom we invasively measured blood pressure in the paretic arm demonstrated blood pressure that was not different from the blood pressure measured noninvasively in the unaffected arm.
A large number of chronic changes such as clubbing, retardation of nail growth, edema, osteoporosis, fractures, arthritis, shoulder dislocation, frozen shoulder, periarticular calcification, muscle wasting, temperature differences, and deep vein thrombosis can occur in paretic extremities after a stroke. Interestingly, some pathologic changes such as rheumatoid arthritis and gouty tophi do not affect paretic limbs after a stroke .
Because of the large and inconsistent differences in blood pressure in the arms of patients with hemiparesis, we suggest that measuring blood pressure in the nonparetic arm of poststroke patients will provide a more reliable monitor of blood pressure during anesthesia.
S. S. Moorthy, MD
Larry Davis, MS
R. V. Reddy, MD
Stephen F. Dierdorf, MD
Departments of Anesthesia and Neurology
Indiana University School of Medicine
Indianapolis, IN 46202
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2. Panayioutou BN, Harper GD, Fotherby MD, et al. Interarm blood pressure difference in acute hemiplegia. J Am Geriatr Soc 1993;41:422-3.
3. Dewar R, Sykes D, Mulkerrin E, et al. The effect of hemiplegia on blood pressure measurement in the elderly. Postgrad Med J 1992;68:88-91.
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