Validation of simple and inexpensive algometry using sphygmomanometer cuff and neuromuscular junction monitor with standardized laboratory algometer

Comparison of efficacy of gabapentin and memantine premedication in laparoscopic cholecystectomies for postoperative pain relief - A randomised placebo controlled trial

Background and Aims:

The multiplicity of the mechanisms of the pain in laparoscopic cholecystectomy inclines us to the usage of multimodal analgesia. Gabapentin is known for its analgesic efficacy when given as premedication in many surgeries. N-methyl-D-aspartate (NMDA) antagonists are used for both acute and chronic pain, but the use of memantine in the perioperative period is less studied. The aim of this randomised controlled study was to subjectively and objectively compare postoperative pain relief using gabapentin, memantine and placebo as premedication.

Methods:

Sixty-six patients posted for laparoscopic cholecystectomy were randomised into three groups. During the preoperative assessment, the baseline threshold and tolerance values of pain were measured using an algesiometer. Patients were pre-medicated with oral gabapentin 600 mg or memantine 20 mg or placebo an hour before surgery. Following extubation, pain scores were reassessed (both subjectively and objectively) along with Ramsay sedation scores at different time intervals for 4 h postoperatively.

Results:

Gabapentin group had lower Numerical Rating Scale scores at 15 min and 1 h postoperatively when compared to the other two groups. Memantine group had a longer time for the first request for rescue analgesia (50.53 min) compared to gabapentin and placebo. The objective assessment of pain with analgesiometer showed no statistical significance between the three groups for both threshold and tolerance values. Ramsay sedation scores were higher in the gabapentin group compared to the other two.

Conclusion:

Gabapentin provides better postoperative pain relief compared to memantine when given as single dose premedication for laparoscopic cholecystectomy.

Hand-held dynamometer to measure pressure pain thresholds: A double-blinded reliability and validity study

BACKGROUND

Pain is the most common complaint reported in the musculoskeletal setting. Quantitative sensory testing (QST) assists with pain mechanism identification, although QST is typically performed in research settings. It is possible that clinical utilization of QST may improve if clinically accessible tools can be reliably and validly used.

OBJECTIVE

To determine if a hand-held dynamometer (HHD) can be a valid and reliable assessment of pressure pain threshold (PPT).

DESIGN

Double-blinded validation study.

METHODS

Eighteen healthy subjects (25.6 ± 3.4 years old) participated in this study. Two testers independently assessed PPT using a HHD and a digital algometer. Assessments followed previously described pressure algometry protocols. Testers and subjects were each blinded to data during assessments.

RESULTS

Intra- and inter-rater reliability were excellent for the foot and face for both devices (ICC's > 0.9). Bland-Altman plots and intraclass correlation coefficients revealed good-excellent agreement with minimal proportional bias when normalizing device force at pain threshold to the circumference of the device applicator (ICC 95%CI: 0.56-0.95). Only poor-good agreement (ICC 95% CI: 0.30-0.76) and significant proportional bias was observed when normalizing to area (pressure).

CONCLUSIONS

Based on the results of this study, when force is normalized by circumference of the applicator, a HHD was found to be a valid and reliable tool for measuring PPT. Clinicians may use HHD to detect relevant pain mechanisms at fault in their evaluation and treatment of pain. Additional research in various pathologic populations is warranted.

Somatosensory Testing in Pediatric Patients with Chronic Pain: An Exploration of Clinical Utility

We aimed to evaluate the utility of clinical somatosensory testing (SST), an office adaptation of laboratory quantitative sensory testing, in a biopsychosocial assessment of a pediatric chronic somatic pain sample (N = 98, 65 females, 7–18 years). Stimulus–response tests were applied at pain regions and intra-subject control sites to cutaneous stimuli (simple and dynamic touch, punctate pressure and cool) and deep pressure stimuli (using a handheld pressure algometer, and, in a subset, manually inflated cuff). Validated psychological, pain-related and functional measures were administered. Cutaneous allodynia, usually regional, was elicited by at least one stimulus in 81% of cases, most frequently by punctate pressure. Central sensitization, using a composite measure of deep pressure pain threshold and temporal summation of pain, was implied in the majority (59.2%) and associated with worse sleep impairment and psychological functioning. In regression analyses, depressive symptoms were the only significant predictor of pain intensity. Functional interference was statistically predicted by deep pressure pain threshold and depressive symptoms. Manually inflated cuff algometry had comparable sensitivity to handheld pressure algometry for deep pressure pain threshold but not temporal summation of pain. SST complemented standard biopsychosocial assessment of pediatric chronic pain; use of SST may facilitate the understanding of disordered neurobiology.

Evaluation of Using the Sphygmomanometer Test to Assess Pain Sensitivity in Chronic Pain Patients vs Normal Controls

OBJECTIVES

Objectively measuring pain sensitivity has not been easy in primary care clinics. A sphygmomanometer test (a sensory test that measures an individual's nociceptive response to pressure using a standard blood pressure cuff) has recently been established to test pain sensitivity. Here, we examined the feasibility of using the sphygmomanometer test with chronic pain patients.

DESIGN

Population, observational study.

SETTINGS

A community hospital multidisciplinary Pain Center and a private nonprofit university.

SUBJECTS

Healthy controls and chronic pain patients were recruited.

METHODS

All subjects underwent four pain sensitivity tests: a pressure algometer test, a cold pressure test, a heat sensitivity test, and a sphygmomanometer test. Participants then completed four established surveys for evaluating depression (Patient Health Questionnaire-9), anxiety (General Anxiety Disorder-7), fatigue (Fatigue Severity Scale), and pain catastrophizing (Pain Catastrophizing Scale).

RESULTS

Although pain patients had significantly higher levels of depression, anxiety, fatigue, and pain catastrophizing, as well as reported pain scores, no significant differences in pain sensitivity were detected via any of the pain sensitivity tests. In the control but not the patient group, results from all pain sensitivity tests including the sphygmomanometer test were significantly correlated with each other. Unlike other pain sensitivity tests, the sphygmomanometer test did not correlate with measures of depression, anxiety, fatigue, or pain catastrophizing characteristics.

CONCLUSIONS

Our results indicate the unique characteristics of the sphygmomanometer test as a pain sensitivity test, particularly when utilized for individuals with chronic pain. Multiple pain sensitivity tests that assess various sensory modalities are needed to evaluate pain sensitivities in chronic pain patients.

Instrumental validity and intra/inter-rater reliability of a novel low-cost digital pressure algometer

Background

Pain assessment is a key measure that accompanies treatments in a wide range of clinical settings. A low-cost valid and reliable pressure algometer would allow objective assessment of pressure pain to assist a variety of health professionals. However, the pressure algometer is often expensive, which limits its daily use in both clinical and research settings.

Objectives

This study aimed to assess the instrumental validity, and the intra- and inter-rater reliability of an inexpensive digital adapted pressure algometer.

Methods

A single rater applied 60 random compressions on a force platform. The pressure pain thresholds of 20 volunteers were collected twice (3 days apart) by two raters. The main outcome measurements were as follows: the maximal peak force (in kPa) and the pressure pain threshold (adapted pressure algometer vs. force platform). Cronbach’s α test was used to assess internal consistency. The standard error of measurement provided estimates of measurement error, and the measurement bias was estimated with the Bland–Altman method, with lower and upper limits of agreement.

Results

No differences were observed when comparing the compression results (P = 0.51). The validity and internal intra-rater consistencies ranged from 0.84 to 0.99, and the standard error of measurement from 0.005 to 0.04 kPa. Very strong (r = 0.73–0.74) to near-perfect (r = 0.99) correlations were found, with a low risk of bias for all measurements. The results demonstrated the validity and intra-rater reliability of the digitally adapted pressure algometer. Inter-rater reliability results were moderate (r = 0.55–0.60; Cronbach’s α = 0.71–0.75).

Conclusion

The adapted pressure algometer provide valid and reliable measurements of pressure pain threshold. The results support more widespread use of the pressure pain threshold method among clinicians.