The Effects of Lavender and Citrus aurantium on Anxiety and Agitation of the Conscious Patients in Intensive Care Units: A Parallel Randomized Placebo-Controlled Trial

Enhancing placebo analgesia: Unravelling the powerful interplay of ownership and verbal suggestion

BACKGROUND

Placebo analgesic research demonstrates pain reduction after using a placebo analgesic. Recent studies have documented that sometimes possessing a placebo analgesic induces placebo analgesia. These prior studies used a 'cream' as the stimulus and proposed that the effect is driven by an expectancy of obtaining benefits from the owned analgesic. This paper examines three pivotal components of placebo analgesia: placebo form, ownership and expectancy induced by verbal suggestion. We investigate analgesic expectancy between cream versus oil form of placebo stimulus and systematically isolate the effects of ownership, verbal suggestion and their interaction, comparing with the effect of use, to decipher the dynamics of placebo analgesia.

METHODS

Study 1 (N = 46) evaluated analgesic expectancy between cream and oil. Study 2 (N = 119) exposed participants to a placebo analgesic oil and randomized them into PU (possess and use), PA (possess and anticipate), P (possess-only) or A (anticipate-only) conditions. Pain outcomes were assessed using a cold pressor test. Comparing PA and P conditions assessed the verbal suggestion effect, comparing PA and A conditions evaluated the possession effect, while comparing PU and PA conditions shed light on the use effect.

RESULTS

In Study 1, participants showed comparable analgesic expectancy for cream and oil. In Study 2, both PA and PU groups performed equally well, reporting higher pain threshold, F(3, 115) = 5.14, p = 0.002,η p 2 $$ {\eta}_p^2 $$  = 0.12; and a greater probability of persistent hand submersion than P and A groups, X2(3) = 8.06, p = 0.045.

CONCLUSION

The findings highlight the significance of integrating possession with expectancy to induce placebo analgesia, which has clinical implications.

SIGNIFICANCE

This study delves into the intricate dynamics of placebo analgesia, shedding light on the significant influence of ownership and verbal suggestion. Through a meticulous exploration of the relationship between ownership and expectancy induced by verbal suggestion, we propose novel avenues for enhancing placebo responses. This research has implications for clinical practice and pain management strategies, potentially revolutionizing approaches to pain relief and therapeutic outcomes. Our findings contribute to a paradigm shift in understanding placebo analgesia, emphasizing the pivotal interaction between ownership and verbal suggestion.

Anxiety-Reducing Effects of Lavender Essential Oil Inhalation: A Systematic Review

Anxiety disorders are the most prevalent and disabling mental disorders, causing health-related burdens. With the increasing demand for and interest in safe and acceptable anxiolytics, several studies report the anxiolytic effects of lavender aromatherapy, providing evidence of its physiological and psychological effects. However, existing reviews comprehensively cover the effects of different modes of delivering aromatherapy. Therefore, this review assesses the efficacy of lavender essential oil inhalation in reducing anxiety. The titles and abstracts of relevant articles published over the last five years were searched in PubMed, Web of Science, and Scopus databases. This review only included clinical trials that utilized lavender inhalation for anxiety treatment. Eleven studies comprising 972 participants were included. Of these, 10 reported significantly decreased anxiety levels after lavender oil inhalation. The physiological measures of vital signs, including blood pressure, heart rate, respiratory rate, pulse, and saturation, were conducted in three trials, showing that lavender oil inhalation could physiologically affect anxiety levels. Lavender oil inhalation is a safe and feasible anxiolytic intervention for treating people with diverse types of anxiety. Data from further studies with a high-quality design and accurate information are necessary to confirm the validity of these findings and elucidate the anxiety-reducing mechanisms of lavender inhalation.

Aromatherapy for the brain: Lavender's healing effect on epilepsy, depression, anxiety, migraine, and Alzheimer's disease: A review article

Neurological diseases affect the nervous system, including the brain, spinal cord, cranial nerves, nerve roots, autonomic nervous system, neuromuscular junctions, and muscles. Herbal medicine has long been used to cure these diseases. One of these plants is lavender, which is composed of various compounds, including terpenes, such as linalool, limonene, triterpenes, linalyl acetate, alcohols, ketones, polyphenols, coumarins, cineole, and flavonoids. In this review, the literature was searched using scientific search engines and databases (Google Scholar, Science Direct, Scopus, and PubMed) for papers published between 1982 and 2020 via keywords, including review, lavender, and neurological disorders. This plant exerts its healing effect on many diseases, such as anxiety and depression through an inhibitory effect on GABA. The anti-inflammatory effects of this plant have also been documented. It improves depression by regulating glutamate receptors and inhibiting calcium channels and serotonergic factors, such as SERT. Its antiepileptic mechanism is due to an increase in the inhibitory effect of GABA and potassium current and a decrease in sodium current. Therefore, many vegetable oils are also used in herbal medicine. In this review, the healing effect of lavender on several neurological disorders, including epilepsy, depression, anxiety, migraine, and Alzheimer's disease was investigated. All findings strongly support the traditional uses of lavender. More clinical studies are needed to investigate the effect of the plants' pharmacological active constituents on the treatment of life-threatening diseases in humans. The limitations of this study are the low quality and the limited number of clinical studies. Different administration methods of lavender are one of the limitations of this review.

Benefit of inhalation aromatherapy as a complementary treatment for stress and anxiety in a clinical setting – A systematic review

OBJECTIVE

The purpose of this systematic review is to ascertain the impact of inhalation aromatherapy on stress and anxiety in clinical settings.

METHODS

A search strategy was developed using various databases. Randomised Controlled Trials (RCTs) as well as single and double-blind pilot clinical studies (non-RCT) using inhalation aromatherapy with an essential oil blend or a single essential oil were examined. All studies included a control intervention and use of a validated measurement tool. The time period under review was years 2000-2021. Due to the high level of heterogeneity and element of bias, a narrative synthesis was conducted.

RESULTS

The search strategy initially retrieved 628 studies and through application of the selection criteria and the removal of duplicates, 76 studies were selected for review with a total of 6539 patients. In 42% of the RCTs, physiological measures including vital signs and/or salivary cortisol were used in addition to questionnaires. Over 70% of the studies reported a positive effect on anxiety levels in the aromatherapy intervention groups compared with the control. However, in many cases this is limited by the absence of safety data, imprecise reporting of plant species and dosage of essential oil.

CONCLUSION

Inhalation aromatherapy has the potential to reduce stress and anxiety with data emerging to further support this result across a wide modality of clinical treatments. However, there is a clear need for the development of standard protocols for research in this area, generating measurable results which will create the opportunity for more rigorous evidence-based outcomes.

The Effects of Essential Oils on the Nervous System: A Scoping Review

Essential oils are a mixture of natural aromatic volatile oils extracted from plants. The use of essential oils is ancient, and has prevailed in different cultures around the world, such as those of the Egyptians, Greeks, Persians, and Chinese. Today, essential oils are used in traditional and complimentary medicines, aromatherapy, massage therapies, cosmetics, perfumes and food industries. The screening effect of essential oils has been studied worldwide. They demonstrate a range of biological activities, such as antiparasitic, antifungal, antibacterial, antiviral, antioxidant, anti-inflammatory, anticancer, antiaging, and neuroprotective properties. In this scoping review, we provide a 10-year updated comprehensive assessment of volatile oils and their effects on the nervous system. MEDLINE, Scopus, and Google Scholar were systematically and strategically searched for original studies investigating these effects from 2012 to 2022. Approximately seventy studies were selected as included studies. Among these studies, several outcomes were reported, including antistress, antianxiety, analgesic, cognitive, and autonomic effects. Some essential oils showed developmental benefits, with the potential to induce neurite outgrowth. The neurotransmitter receptor level can also be modified by essential oil application. Physiological and pathophysiological outcome measures were reported. For physiological outcomes, arousal, cognitive performance, circadian eating behavior, emotional modulation, consumer acceptance, preferences, and willingness to buy were investigated. For pathophysiological conditions, pain, depression, anxiety, stress, sleep disorder, mental fatigue, agitated behavior, and quality of life were measured. In conclusion, essential oils showed promising effects on the nervous system, which can be further applied to their use in functional foods, drinks, and alternative therapy.

Effectiveness of aromatherapy on anxiety and sleep quality among adult patients admitted into intensive care units: A systematic review

PURPOSE

This review aims to evaluate the effectiveness of aromatherapy on anxiety and sleep quality among adult patients admitted to an intensive care unit.

MATERIALS AND METHODS

A systematic search for published and unpublished studies across nine databases and sources were conducted. Randomised Controlled Trials and Controlled Clinical Trials, which assessed the effectiveness of aromatherapy on anxiety and sleep quality among intensive care unit patients, were included in this review. Only studies that used aromatherapy as a single intervention were included. Narrative synthesis was conducted across all outcomes due to high heterogeneity across studies.

RESULTS

A total of 26 studies involving 2176 participants across six countries were included in this review. Most studies had an overall high risk of bias. Publication bias was detected in the studies. Findings have shown that aromatherapy may be effective in reducing anxiety based on the low GRADE certainty of evidence, and improving sleep quality based on the very low GRADE certainty of evidence. Inconsistencies in findings were also observed.

CONCLUSION

Aromatherapy might be beneficial on anxiety and sleep quality among intensive care unit patients, however, the level of evidence is very low, based on the low quality of studies. Considerations can be made to incorporate aromatherapy into existing interventions that improve anxiety and sleep quality in the intensive care unit. Due to inconsistencies in findings, further research can be done to investigate and strengthen these evidence.

IMPLICATION FOR CLINICAL PRACTICE

This review has demonstrated that aromatherapy may have benefits on anxiety and sleep quality. Despite uncertain evidence, aromatherapy may still be considered as a complementary or alternative option to improve anxiety and sleep quality among intensive care patients as it is relatively safe, cost-effective and easy to implement (Buckle, 2014). However, proper training by a professional clinical aromatherapist is needed to ensure there is screening of patients for suitability, proper technique for administering aromatherapy, safe handling of essential oils and monitoring for adverse events (Farrar & Farrar, 2020).

A Narrative Review of the Effects of Citrus Peels and Extracts on Human Brain Health and Metabolism

As life expectancy increases, age-associated diseases such as Alzheimer's disease (AD) become a major health problem. The onset of AD involves neurological dysfunction due to amyloid-β accumulation, tau hyperphosphorylation, oxidative stress, and neuroinflammation in the brain. In addition, lifestyle-related diseases-such as dyslipidemia, diabetes, obesity, and vascular dysfunction-increase the risk of developing dementia. The world population ages, prompting the development of new strategies to maintain brain health and prevent the onset of dementia in older and preclinical patients. Citrus fruits are abundant polymethoxylated flavone and flavanone sources. Preclinical studies reported that these compounds have neuroprotective effects in models of dementia such as AD. Interestingly, clinical and epidemiological studies appear to support preclinical evidence and show improved cognitive function and reduced associated disease risk in healthy individuals and/or patients. This review summarizes the recent evidence of the beneficial effects of citrus peels and extracts on human cognition and related functions.