Background & Aims

Over 40 million Americans experience chronic pain. Pharmacological approaches to chronic pain are accompanied by adverse effects such as dry mouth, weight gain, cognitive and sexual dysfunction, and risk for addiction. Aromatherapy is a novel approach to chronic pain. Essential oils (EOs) are extracted from aromatic plants and support health by eliciting physiological and psychological effects primarily through inhalation and topical application. EOs moderate many aspects of pain signal transmission, including non-competing inhibition of 5-HT, AChE, and Substance P and antagonism of TRPA1 and TRPV1. A novel approach to physiologically demonstrating essential oils’ pain-reducing efficacy is through local thermal hyperemia (LTH). The study’s primary and secondary aims are to ascertain the effect of select EOs on substance P and nitric oxide released by local sensory neurons during LTH in healthy adults and determine if demographic differences impact these effects.

Methods

The study is a quasi-experimental, one-group, pre and post-test design. Healthy adults are being recruited from the SE United States using convenience sampling. Inclusion criteria include 18 years of age or older, English speaking, no neuropathic or cardiovascular diagnoses, and no use of prescription medications or illegal substances. Exclusion criteria include pregnancy or breastfeeding, injury or trauma to the right forearm or non-intact skin, consuming twelve or more alcoholic beverages per week, allergy to select EOs or adhesives, and scoring > 2 on the SF-MPQ-2 and the VAS. An a priori power analysis, ? = 0.05, ? = 0.80, and ? = 0.05, equated to a sample size of 27. A counterbalanced sequence will be used for testing control, placebo, and 16 select EOs as 10% dilutions. LTH utilizes a Class 1 laser to non-invasively measure microvascular blood flow via scattered Doppler flux during the axon reflex, arc through plateau. Study equipment includes the moorVMS-LDF2 and moorVMS-HEAT.

Results

Data will be entered into Microsoft Excel for data management, and SAS statistical software will be used for data analysis. Continuous and categorical variables will be summarized using simple measures of summary statistics, frequencies, and percentages. Tests for normality will be performed using a univariate procedure. The Shapiro-Wilk test will be utilized to assess the normality of data. Parametric or non-parametric statistical methods will be used based on the distribution of data. For the primary aim, a paired t-test or Wilcoxon signed rank test will be used to assess the mean difference for comparing measurements from the same individual. For the secondary aim, we will use simple and multiple regression methods to ascertain the effect of demographic variables on the outcome. Study findings will be reported using the CONSORT Herbal Medicinal Intervention Extension and the ARQAT TREATS checklist.

Conclusions

In our 2017 study (n = 20), in which single EO testing was not feasible, a blend of six EOs demonstrated substance P inhibition (p = .036) compared to placebo in healthy adults. In our 2019 pilot RCT of breast cancer survivors with chemotherapy-induced neuropathic pain (n = 26), the EO blend demonstrated pain reduction (p = .001) in intervention group participants who took pain medications also – suggesting adjuvant effects. Results from this study will be used to enhance the potential pain-reducing effects of our previously tested EO blend for neuropathic and other chronic pain conditions. Further research will include additional EOs, CO2 extracts, hydrosols, and herbal-infused oils to create natural products for pain reduction.

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Presenting Author

Dawn L. Langley-Brady

Poster Authors

Dawn Langley-Brady

PhD, MSN, BFA, ASN, PND

College of Nursing, Augusta University, Augusta, Georgia, U.S.A.

Lead Author

Julie K. Zadinsky

PhD, RN

College of Nursing, Augusta University, Augusta, Georgia, U.S.A.

Lead Author

Thomas Joshua

PhD

School of Public Health, Augusta University, Augusta, Georgia, U.S.A

Lead Author

K. M. Monirul Islam

MD, PhD

School of Public Health, Augusta University, Augusta, Georgia, U.S.A

Lead Author

Topics

  • Assessment and Diagnosis