The Influence of Acupressure on the Monitoring of Acoustic Evoked Potentials in Unsedated Adult Volunteers

Transcutaneous electrical acupoint stimulation induced sedative effects in healthy volunteers: A resting-state fMRI study

Background

Previous studies indicated the sedative effect of acupoint stimulation. However, its mechanism remains unclear. This study aimed to investigate the sedative effect of transcutaneous electrical acupoint stimulation (TEAS) and to explore the brain regions involved in this effect in healthy volunteers using functional magnetic resonance imaging (fMRI) techniques.

Methods

In this randomized trial, 26 healthy volunteers were randomly assigned to the TEAS group (receiving 30 min of acupoint stimulation at HT7/PC4) and the control group. fMRI was conducted before and after the intervention. The primary outcome was the BIS value during the intervention. Secondary outcomes included the amplitude of low-frequency fluctuation (ALFF) and region of interest (ROI)-based functional connectivity (FC) showed by fMRI.

Results

In healthy volunteers, compared with the control group, ALFF values in the TEAS-treated volunteers decreased in the left thalamus, right putamen, and midbrain, while they increased in the left orbitofrontal cortex. More FC existed between the thalamus and the insula, middle cingulate cortex, somatosensory cortex, amygdala, and putamen in subjects after TEAS treatment compared with subjects that received non-stimulation. In addition, ALFF values of the thalamus positively correlated with BIS in both groups.

Conclusion

Transcutaneous electrical acupoint stimulation could induce a sedative effect in healthy volunteers, and inhibition of the thalamus was among its possible mechanisms.

Clinical trial registration

www.ClinicalTrials.gov; identifier: NCT01896063.

AKUPRESSUR, NEUROPHARMAKOLOGIE UND PSYCHISCHE GESUNDHEIT

Akupressur ist eine nicht pharmakologische Technik, die das Potenzial hat, verschiedene Krankheiten zu lindern. Diese Kurzübersicht beschäftigt sich mit Fakten wissenschaftlicher Akupressurstudien und fasst einige wichtige Aspekte zusammen. Wissenschaftliche Artikel aus den Datenbanken PubMed, Google Scholar und CNKI dienten als Forschungsdokumente. Darüber hinaus umfasste die Forschung zur Akupressur im Vergleich zu pharmakologischen Interventionen bei mentalen Erkrankungen eigenes Material, das bereits in wissenschaftlichen Artikeln veröffentlicht wurde. Insgesamt wurden 9 gelistete Publikationen identifiziert, von denen 8 als relevant angesehen wurden. Der Autor überprüfte den Inhalt auf Wertigkeit und diskutiert in diesem Artikel die Einschränkungen der nicht pharmakologischen Behandlungsmethode kritisch. Die verfügbaren Beweise, dass Akupressur als zusätzliche nicht pharmakologische Methode zur Intervention bei mentalen Erkrankungen eingesetzt werden kann, sind spärlich. Es konnte keine evidenzbasierte Qualitätsstudie identifiziert werden, in der Akupressur mit pharmakologischen Behandlungen bei mentalen Erkrankungen direkt verglichen wird. Obwohl bei der Bewertung der alten traditionellen Akupressurmethode erhebliche Fortschritte erzielt wurden, werden in den kommenden Jahren weitere Forschungsarbeiten wie beispielsweise gut konzipierte randomisierte kontrollierte Studien erforderlich sein.

Shiatsu and Acupressure: Two Different and Distinct Techniques

BACKGROUND

Although shiatsu has been taught in specialized schools in Japan since 1940, there is a limited amount of research for its practice. As a result, authors substitute shiatsu with acupressure to use available research on acupressure. It is the position of the authors that, while the two share common aspects, they are substantively different. This project was undertaken to describe technical differences and advocate for a clear distinction, especially in research studies and academic discussions.

METHODS

To understand whether it is appropriate to include acupressure studies in the evidence for shiatsu an analysis of the references included in a frequently cited systematic review was conducted to collect information about the protocols. In addition, a preliminary exploration of shiatsu practitioners' perceptions about the differences between shiatsu and acupressure is described. This exploration used videos of shiatsu and acupressure techniques and asked practitioners to comment on their perception of similarity.

DISCUSSION

The results identified several key technical differences between the two, including type of pressure applied, the positioning of the thumb, and the way in which body weight is used. Researchers should separate shiatsu and acupressure in their designs and purposively choose one or the other. To facilitate such clarification, we have proposed a definition for shiatsu that may facilitate the differentiation between these two techniques.

CONCLUSION

The authors hope to stimulate discussion about the differences between shiatsu and acupressure, and to question the appropriateness of using acupressure studies as evidence of the efficacy of shiatsu. A true understanding of the efficacy of shiatsu cannot be determined until studies use a common definition of shiatsu and discontinue substituting acupressure research for evidence of shiatsu efficacy. When this happens, it is proposed that a clearer picture of the safety, efficacy, and mechanism of action of both shiatsu and acupressure will emerge.

Evaluation of peripheral perfusion in term newborns before and after Yintang (EX-HN 3) massage

OBJECTIVE

To identify how acupressure on the acupoint Yintang (EX-HN 3) impacts oxygen saturation, pulse rate, and peripheral perfusion in term-born infants without underlying disease.

METHODS

Infants born between weeks 37 and 42 of gestation were included in this study. The polyclinic's neonatology room was noise-controlled and made half-dark to prevent the perfusion index from being confounded. A pulse oximeter was linked to the baby's left lower extremity. Acupressure was applied on Yintang (EX-HN 3) for 30 s clockwise, held for 30 s, and then acupressure was applied for another 30 s counterclockwise. The baby's SaO2, pulse rate, and perfusion index were recorded for each minute before and after acupressure.

RESULTS

When pre- and post-acupressure pulse rate values were compared, a significant decrease in pulse rate values after acupressure application was observed. When pre- and post-acupressure oxygen saturation values were compared, a significant increase in post-acupressure oxygen saturation was observed. In addition, peripheral perfusion increased significantly after acupressure.

CONCLUSION

Acupressure application has been used in traditional medicine for many years. However, it is not yet widely used in modern medicine. This study shows the impact of acupressure on neonatal skin perfusion, oxygen saturation, and pulse rate.

Acupuncture on Yintang point decreases preoperative anxiety

OBJECTIVES

The aim of this study was to investigate the effect of ear-press needle acupuncture on Yintang point for preoperative anxiety.

DESIGN

This was a prospective, randomized, single-blind, controlled study.

SETTINGS/LOCATION

The study setting was the Department of Anesthesiology in Ankara Training and Research Hospital of Ministry of Health, Ankara, Turkey.

SUBJECTS

The study comprised 52 adult surgical patients.

INTERVENTIONS

A single, 20-minute session of single-point acupuncture was applied on Yintang (acupuncture group) or sham point (sham acupuncture group).

OUTCOME MEASURES

The efficacy of acupuncture was evaluated by means of the changes in bispectral index (BIS) and STAI (State-Trait Anxiety Index).

RESULTS

BIS values in the acupuncture group were significantly lower than in the sham group in all time intervals (p<0.0042). BIS values were lower than baseline in the study group during the entire study period (p<0.0004) while no such effect has been observed in the sham group (p>0.0004). Mean values of state anxiety (STAI-S) decreased after acupuncture in the study group (p=0,018), while no change was observed in trait anxiety (STAI-T) (p=0.156). Patients of the sham group showed no change in both parameters (p=0.387 and p=0,116).

CONCLUSIONS

Ear-press needle acupuncture on Yintang point reduces preoperative anxiety in adult surgical patients.

Limitations of anaesthesia depth monitoring

PURPOSE OF REVIEW

We critically review brain function monitors based on the processed electroencephalogram with regards to signal quality, artefacts and other limitations in clinical performance.

RECENT FINDINGS

Several studies have been showing that depth of anaesthesia monitors based on processed electroencephalogram has limitations that can lead to a wrong interpretation of the level of anaesthesia. Processed electroencephalogram indices can be altered by nonanaesthetic influences ranging from artefacts that affect signal quality and signal processing, adverse effects of some anaesthetic and nonanaesthetic drugs, neuromuscular blocking agents to conditions inherent to the patient such as cerebral tumours, brain ischemia and temperature.

SUMMARY

Clinicians should be aware of the several limitations of the commercial devices intending to monitor the depth of anaesthesia, which may not reflect the real underlying level of unconsciousness.

The evidence for Shiatsu: a systematic review of Shiatsu and acupressure

Background

Shiatsu, similar to acupressure, uses finger pressure, manipulations and stretches, along Traditional Chinese Medicine meridians. Shiatsu is popular in Europe, but lacks reviews on its evidence-base.

Methods

Acupressure and Shiatsu clinical trials were identified using the MeSH term 'acupressure' in: EBM reviews; AMED; BNI; CINAHL; EMBASE; MEDLINE; PsycARTICLES; Science Direct; Blackwell Synergy; Ingenta Select; Wiley Interscience; Index to Theses and ZETOC. References of articles were checked. Inclusion criteria were Shiatsu or acupressure administered manually/bodily, published after January 1990. Two reviewers performed independent study selection and evaluation of study design and reporting, using standardised checklists (CONSORT, TREND, CASP and STRICTA).

Results

Searches identified 1714 publications. Final inclusions were 9 Shiatsu and 71 acupressure studies. A quarter were graded A (highest quality). Shiatsu studies comprised 1 RCT, three controlled non-randomised, one within-subjects, one observational and 3 uncontrolled studies investigating mental and physical health issues. Evidence was of insufficient quantity and quality. Acupressure studies included 2 meta-analyses, 6 systematic reviews and 39 RCTs. Strongest evidence was for pain (particularly dysmenorrhoea, lower back and labour), post-operative nausea and vomiting. Additionally quality evidence found improvements in sleep in institutionalised elderly. Variable/poor quality evidence existed for renal disease symptoms, dementia, stress, anxiety and respiratory conditions. Appraisal tools may be inappropriate for some study designs. Potential biases included focus on UK/USA databases, limited grey literature, and exclusion of qualitative and pre-1989 studies.

Conclusions

Evidence is improving in quantity, quality and reporting, but more research is needed, particularly for Shiatsu, where evidence is poor. Acupressure may be beneficial for pain, nausea and vomiting and sleep.

[Measurement of the depth of anaesthesia]

One of the most important mandates of the anaesthesiologist is to control the depth of anaesthesia. An unsolved problem is that a straight definition of the depth of anaesthesia does not exist. Concerning this it is rational to separate hypnosis from analgesia, from muscle relaxation and from block of cardiovascular reactions. Clinical surrogate parameters such as blood pressure and heart rate are not well-suited for a valid statement about the depth of hypnosis. To answer this question the brain has become the focus of interest as the target of anaesthesia. It is possible to visualize the brain's electrical activity from anelectroencephalogram (EEG). The validity of the spontaneous EEG as an anesthetic depth monitor is limited by the multiphasic activity, especially when anaesthesia is induced (excitation) and in deep anaesthesia (burst suppression). Recently, various commercial monitoring systems have been introduced to solve this problem. These monitoring systems use different interpretations of the EEG or auditory-evoked potentials (AEP). These derived and calculated variables have no pure physiological basis. For that reason a profound knowledge of the algorithms and a validation of the monitoring systems is an indispensable prerequisite prior to their routine clinical use. For the currently available monitoring systems various studies have been reported. At this time it is important to know that the actual available monitors can only value the sedation and not the other components of anaesthesia. For example, they cannot predict if a patient will react to a painful stimulus or not. In the future it would be desirable to develop parameters which allow an estimate of the other components of anaesthesia in addition to the presently available monitoring systems to estimate sedation and muscle relaxation. These could be sensoric-evoked potentials to estimate analgesia and AEPs for the detection of awareness.

Heart Rate and Electroencephalogram Changes Caused by Finger Acupressure on Planta Pedis

Preliminary experiments were carried out to investigate the feasibility of using an electroencephalogram and heart rates to evaluate the efficacy of finger acupressure on the key points of planta pedis (both soles). Continuous electroencephalograms were recorded from 19 electrodes based on the International 10-20 electrode placement system on 22 university students (21+/-2.3 years). Spectral power changes were obtained at each electrode site. The power of the alpha1 frequency range (8-10 Hz) increased slightly during acupressure although no statistical significance was observed, while heart rates decreased in all subjects (p<0.05). Cerebral cortex asymmetry in the spectral power changes was not clearly observed during the right and left sole acupressure. This preliminary study suggests that a classification of subjects is necessary in understanding brain wave data during acupressure on soles.

Correlation of the A-Line™ ARX index with acoustically evoked potential amplitude †

BACKGROUND

Automated indices derived from mid-latency auditory evoked potentials (MLAEP) have been proposed for monitoring the state of anaesthesia. The A-Line ARX index (AAI) has been implemented in the A-Line monitor (Danmeter, V1.4). Several studies have reported variable and, in awake patients, sometimes surprisingly low AAI values. The purpose of this study was to reproduce these findings under steady-state conditions and to investigate their causes.

METHODS

Ten awake unmedicated volunteers were studied under steady-state conditions. For each subject, the raw EEG and the AAI were recorded with an A-Line monitor (V1.4) during three separate sessions of 45.0 (1.6) min duration each. MATLAB (Mathworks) routines were used to derive MLAEP responses from EEG data and to calculate maximal MLAEP amplitudes.

RESULTS

The AAI values ranged from 15 to 99, while 11.4% fell below levels which, according to the manufacturer, indicate an anaesthetic depth suitable for surgery. Inter-individual and intra-individual variation was observed despite stable recording conditions. The amplitudes of the MLAEP varied from 0.8 to 42.0 microV. The MLAEP amplitude exceeded 2 microV in 75.3% of readings. The Spearman's rank correlation coefficient between the MLAEP amplitude and the AAI value was r=0.89 (P<0.0001).

CONCLUSIONS

The version of the A-Line monitor used in this study does not exclude contaminated MLAEP signals. Previous publications involving this version of the A-Line monitor (as opposed to the newer A-Line/2 monitor series) should be reassessed in the light of these findings. Before exclusively MLAEP-based monitors can be evaluated as suitable monitors of depth of anaesthesia, it is essential to ensure that inbuilt validity tests eliminate contaminated MLAEP signals.

Bispectral index evaluation of the sedative effect of acupuncture in healthy volunteers

OBJECTIVE

To evaluate the sedative effect of acupuncture in healthy volunteers by means of the BIS monitor. Secondary end-points were the evaluation of subjective sedative sensation induced by acupuncture and possible lasting of the sedative effect post needles removal.

METHODS

We performed a cross-over, single-blinded study on 10 healthy volunteers to evaluate objective and subjective sedative effect of acupuncture compared to sham acupuncture. We recorded heart rate, pulse-oxymetry, BIS at baseline, during a 20-min. stimulation period, and for the following 20 minutes after needles removal. Besides, we asked volunteers to score their subjective state by VAS at baseline, after the stimulation period (20th minute) and 20 minutes after needles removal.

RESULTS

BIS values were not significantly different between true and sham acupuncture. A suggestive but not statistically significant difference was evident in VAS score, with true- better than sham acupuncture. There was no difference in the incidence of sleep during the experimental phases, nor in the incidence of insomnia or somnolence in the following 24 hours. HR and SpO2 remained always in a normal range.

CONCLUSIONS

The sedative effect of true acupuncture was not different from that of sham acupuncture in healthy volunteers. We suggest that acupuncture could have a mild sedative action that can be demonstrated only treating anxious patients and not calm volunteers. In our opinion, the low potency of this technique can be an advantage allowing acupuncture safe application in a wide range of settings.