Abstract ID: A2
Abstract Title: Do the characteristics of ongoing and evoked postamputation pain and the changes in mood, cognition, and physical function differ based on the etiology for amputation?
Poster Type: Poster
ABSTRACT BODY
Background: Post amputation pain has a debilitating impact on rehabilitation and quality of life of amputees. Characterizing the nature of the ongoing and evoked pains after amputation, based on etiology, and the resultant changes in mood and function may help identify patients with higher risk of developing post-amputation pains and develop preventive strategies.
Objective: To characterize the ongoing and stimulus-evoked pain and alterations in mood, cognitive and physical function in patients with amputations resulting from trauma, vascular insufficiency, and other etiologies.
Methods: Demographic data and baseline pain scores were obtained after withdrawal from analgesics from 57 patients who participated in a randomized clinical trial. Quantitative sensory testing was performed in the area of maximum pain or hyperalgesia and the corresponding contralateral side. Sensory testing included mechanical detection and pain thresholds using calibrated vonFrey filaments, and thermal detection thresholds using a Peltier device. Cognitive function was established with symbol substitution task, verbal learning and grooved pegboard. Physical functioning (Multidimensional Pain Inventory) and mood (Beck Depression Inventory) were also studied. Data were analyzed using chi-square test and ANOVA.
Results: Forty four males and 13 females participated in the study (mean age + SEM -54.2 ± 1.9 yr). Age between groups was significantly different (p<0.0001). Of these 23 patients had amputations after trauma (Gp I, 45.9 ± 2.3yr), 23 for vascular insufficiency (Gp II, 63 ± 2.4 yr), and 11 for other reasons such as malignancy and chronic infections (Gp III, 53.2, ± 4.5 yr). The site of amputation was significantly different between groups (p<0.003) with more upper extremity amputations in Gp I (10/23) as compared to Gp II (1/23) and Gp III (1/11) causes. Patients in Gp II were either disabled or retired while 30% of amputees in Gp I and 27% in Gp III were employed at time of enrollment. Most patients in all 3 groups had both stump and phantom pains. The intensity of stump and phantom pains was similar in the 3 groups. The mean stump pain intensity was 6.8 ± 2.5, 6.8 ± 3.1, and 6.3 ± 1.7 in Gps I, II, and III, respectively. Similarly the mean phantom pain intensities were 7.1 ± 2.7, 6.6 ± 2.5, and 7.3 ± 1.3. A difference of >1°C between the thermal thresholds on the affected and unaffected sides was defined as significant. The difference in heat/cold thresholds and heat pain were similar between groups. Gp I had 6/14 patients with hypoalgesia to cold, while only 2/15 in Gp II and 1/10 Gp III had similar changes in cold pain (p<0.04). No differences between the 3 groups were observed in response to mechanical stimuli, mood, cognitive and physical function.
Conclusion: Amputations resulting from vascular insufficiency and other causes were predominantly in the lower extremity while traumatic amputations occurred with equal frequency in the upper and lower limbs. The pain intensity, presence of stump and phantom pain, and the alterations in sensibility at the stump were similar in the 3 different etiological groups. The effects of the amputation on mood and physical functioning are not different in the 3 groups of patients.
ATTACHED FILES
Reg Anesth Pain Med 2004; 29(2):A2