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Reg Anesth Pain Med. Author manuscript; available in PMC 2016 November 01. Published in final edited form as: Reg Anesth Pain Med. 2015 ; 40(6): 687–693. doi:10.1097/AAP.0000000000000315.
Pressure Pain Sensitivity in Patients With Suspected OpioidInduced Hyperalgesia
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Ronald A. Wasserman, MD, Afton L. Hassett, PsyD, Steven E. Harte, PhD, Jenna Goesling, PhD, Herbert L. Malinoff, MD, Daniel W. Berland, MD, Jennifer Zollars, BA, Stephanie E. Moser, PhD, and Chad M. Brummett, MD Division of Pain Research and the Back and Pain Center, Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan
Abstract Background and Objectives—This study was designed to test whether a brief quantitative sensory testing (QST) assessment could be used to detect hyperalgesia in patients with suspected opioid-induced hyperalgesia. Methods—Twenty patients on long-term opioid therapy with suspected opioid-induced hyperalgesia were recruited along with and 20 healthy controls. Pressure pain threshold, Pain50, a measure of intermediate suprathreshold pressure pain sensitivity, and tolerance levels, were evaluated. As a secondary outcome, changes in pressure pain sensitivity following intravenous administration of placebo (saline) and fentanyl (1.5 μg/kg) were assessed.
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Results—There were no significant differences in pain measures between healthy controls and patients. However, there was an association between higher doses of opioids and having a lower pain tolerance (r= -0.46, P=0.041) and lower Pain50 (r=-0.46, P = 0.044), which was consistent with the hypothesis. Patients on >100 mg oral morphine equivalents (OME) displayed decreased pressure pain tolerance compared to patients taking 100 mg OME were significantly more sensitive for tolerance and showed similar trends for threshold and Pain50. When observing all 3 groups, a pattern was observed to show patients 100 mg OME being more pain sensitive when compared to the healthy controls.
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Wasserman et al.
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Figure 3. Change in quantitative sensory testing (QST) after the fentanyl challenge
The figure shows the changes in the 3 QST outcomes when subtracting the post-fentanyl challenge results from the post-placebo challenge. Male patients demonstrated a hyperalgesic response to the fentanyl challenge (change score < 0) when compared with healthy males and female patients.
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Table 1
Baseline descriptive data
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Healthy Controls
Patients
N = 20
N = 20
P-value
Demographics Age
29.2 (13.2)
44.5 (9.2)
< 0.001
Sex (% Male)
50%
35%
0.337
Race (% Caucasian)
61%
95%
0.022
Pain Severity (BPI)
0.1 (0.2)
6.2 (1.3)
< 0.001
Neuropathic pain (PainDETECT)
0.3 (1.0)
19.7 (7.4)
< 0.001
Fibromyalgia Survey Score
1.1 (1.2)
14.2 (7.6)
< 0.001
Catastrophizing
1.5 (2.7)
17.8 (8.4)
< 0.001
Depressive symptoms (HADS)
0.9 (1.1)
9.2 (3.8)
< 0.001
Pain Phenotype
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Anxiety symptoms (HADS)
1.5 (1.7)
9.4 (3.7)
< 0.001
Fatigue (PROMIS)
10.1 (1.0)
24.3 (5.2)
< 0.001
Sleep (PROMIS)
12.3 (3.0)
33.3 (5.7)
< 0.001
The patient group was significantly older and had a higher percentage of Caucasians. As expected, the patient group also reported a significantly worse pain phenotype. Note: Means and standard deviations are presented for continuous variables, and percentages are presented for dichotomous variables. Mean differences assessed using t-test, and percent differences were assessed using the chi-square test. BPI = Brief Pain Inventory; HADS = Hospital Anxiety and Depression Scale; PROMIS = Patient Reported Outcomes Measurement Information System.
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Table 2
Quantitative Sensory Testing Results
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There were no differences detected in the mean (standard deviation) quantitative sensory testing (QST) results between suspected opioid-induced hyperalgesia (OIH) patients and healthy controls. Healthy
Patients
N = 20*
N = 20
P-value
Threshold
3.0 (1.2)
2.7 (1.4)
0.432
Pain50
5.3 (1.4)
5.7 (1.5)
0.489
Tolerance
6.1 (1.2)
6.5 (1.6)
0.353
Threshold
2.6 (1.1)
2.9 (1.5)
0.499
Pain50
4.9 (1.7)
5.7 (1.7)
0.130
Tolerance
5.8 (1.7)
6.6 (1.8)
0.173
Threshold
3.0 (1.3)
3.6 (1.9)
0.328
Pain50
5.6 (2.0)
6.0 (2.0)
0.589
Tolerance
6.4 (1.9)
6.9 (2.0)
0.422
Baseline QST
Post-placebo QST
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Post-fentanyl QST
All quantitative sensory testing (QST) values listed are kg/cm2. *
Note that 2 healthy participants do not have data included for placebo & fentanyl QST.
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Table 3
Baseline Tolerance, Threshold, and Pain50 controlling for age and gender
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In this multivariate linear regression model controlling for age and sex, there were no differences between healthy controls and patients for measures of evoked pain. Threshold Coefficient
SE
P-value
Participant type
0.37
0.47
0.439
Age
-0.05
0.02
0.012
Sex
-0.11
0.39
0.786
Intercept
4.41
0.61