The effect of ambulation on post-myelography headache in patients injected with metrizamide

This study was conducted to determine whether prescribed ambulation in post-myelography patients injected with metrizamide would significantly decrease the incidence of post-myelography headache. Eighty patients undergoing metrizamide lumbar myelography were assigned to two groups of 40 patients each. The control group was restricted to complete bedrest for the immediate 24-hour period following myelography. The experimental group participated in a prescribed regimen of ambulation every four hours following myelography. Data were collected during the immediate 24 hours post-myelography. Subjects were assessed as to the presence or absence of headache at four-hour intervals during data collection. At the end of the 24-hour period post-myelography, the Visual Analogue Pain Intensity Scale was administered to subjects with documented subjective complaints of headache pain. The nonambulatory group had a 62.5% incidence of headache while the ambulatory group revealed only a 42.5% incidence of post-myelography headache. The z test was used to test the first research hypothesis that there would be a higher incidence of post-myelography headache in the nonambulatory group than in the ambulatory group. The calculated z = 1.79, p less than .05; therefore, it was possible to conclude that the number of nonambulatory patients with headache was significantly higher than the number of ambulatory patients with headache. The second research hypothesis, that the severity of post-myelography headache would be greater in the nonambulatory group than in the ambulatory group, was tested using the Student's t test. The calculated t = .6492, p greater than .05. The subjects' self-perception of the severity of headache was not significantly different in the nonambulatory than in the ambulatory subjects.