Skin Conductance Fluctuations Research Articles

Decreases in Sympathetic Activity Due to Low-Intensity Extremely Low-Frequency Electric Field Treatment Revealed by Measurement of Spontaneous Fluctuations in Skin Conductance in Healthy Subjects

Decreases in Sympathetic Activity Due to Low-Intensity Extremely Low-Frequency Electric Field Treatment Revealed by Measurement of Spontaneous Fluctuations in Skin Conductance in Healthy Subjects

Electrodermal lability and sensorimotor preparation: effects on reaction time, contingent negative variation, and heart rate

Electrodermal lability is a trait-like measure of spontaneous sympathetic resting activity. In the present study, we addressed whether interindividual differences in this lability have an impact on the reaction time (RT) and on two physiological indicators of a goal-oriented sensorimotor preparation in a long-running, forewarned RT task (S1-S2 paradigm). The two indicators were the brain’s contingent negative variation (CNV) and a heart rate deceleration (HRD). The interindividual differences were determined by counting spontaneous skin conductance fluctuations during a 5-min resting phase and dividing the subjects into two groups: individuals below (stable) and above (labile) the median of these fluctuations. In the task, labile individuals had a shorter RT compared with stable individuals and showed in the final phase of preparation in both physiological indicators the stronger response. Thus, lability-dependent effects in forewarned RT tasks cannot be explained by differences in stimulus-driven or passively controlled processes alone. Rather, goal-oriented, deliberately controlled processes that serve to adequately prepare for an imperative stimulus—the S2 in our paradigm—also must be considered to explain them. Labile individuals not only react faster than stable ones but also intentionally prepare themselves more appropriately for the imperative stimulus. A norepinephrine hypothesis focusing on the tonic activity of the locus coeruleus (LC) is proposed as an explanation for these and other lability-dependent effects. The frequency of spontaneous electrodermal fluctuations at rest may represent a peripheral, noninvasive, and easily measurable indicator of the baseline LC activity during wakefulness.

Acute dissociation as part of the defense cascade: Associations with behavioral, autonomic, and experiential threat responses in posttraumatic stress disorder.

Dissociative symptoms, such as depersonalization and derealization, are experienced by about half of individuals with posttraumatic stress disorder (PTSD). Theoretical models propose that acute dissociation is accompanied by specific behavioral, physiological, and experiential alterations and contributes to unfavorable PTSD symptom course. Yet, empirical evidence is scarce. Here, we explored associations between dissociative and behavioral, physiological, and experiential threat responses as well as effects of dissociative responding on PTSD symptom course. Individuals with PTSD (N = 71) participated in a preregistered script-driven imagery study including exposure to standardized, detail-enriched trauma, and neutral scripts. Stabilometry, eye-tracking, facial electromyography, autonomic psychophysiology, and self-report data were collected. Moreover, PTSD symptoms were assessed before and 3 months after testing. Analyses did not link acute dissociation to bodily and facial immobility or staring in response to trauma scripts. However, dissociation displayed an inverted U-shaped relationship with heart rate and was linked to higher nonspecific skin conductance fluctuation and higher high-frequency heart rate variability in response to trauma scripts. Moreover, acute dissociation was linked to higher self-reported negative affect responses to trauma scripts and displayed a U-shaped relationship with unfavorable PTSD symptom course. While results did not confirm hypothesized behavioral markers of dissociation, they do support defense-cascade model assumptions of an inverted U-shaped relationship between dissociation and psychophysiological arousal resulting from a progression of parasympathetic versus sympathetic dominance with increasing dissociation. On an experiential level, results did not confirm posttraumatic dissociation-induced emotional numbing, questioning theoretical notions. The observed nonlinear associations may help explain the heterogeneity of prior findings and might inform an updated conceptualization of posttraumatic dissociation. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Evaluation of nociception in unconscious critically ill patients using a multimodal approach

This prospective observational study included 80 adults (>18 years) patients admitted to the intensive care unit who were unconscious (Glasgow Coma Scale [GCS] score <9 with a motor response <5) and receiving mechanical ventilation. A tetanic stimulation was used to assess nociception; automated pupillometry (Algiscan, ID-MED, France) was used to compute the pupillary pain index score (PPI), with a PPI > 4 considered as nociception. Concomitantly, the number of skin conductance fluctuations (NSCF) per second, measured using a Skin Conductance Algesimeter (SCA, MEDSTORM Innovation AS, Norway; > 0.27 fluctuations/sec indicating nociception), and the instantaneous Analgesia Nociception Index (iANI, MDoloris Medical Systems, France; <50 indicating nociception) were collected.Tetanic stimulation resulted in a median pupillary dilation of 16 [6–25]% and a PPI of 5 [2–7]. According to the PPI assessment, 44 patients (55%) had nociception, whereas 23 (29%) and 18 (23%) showed nociception according to the algesimeter and iANI assessment, respectively. No significant changes in measured physiologic variables were observed after the tetanic stimulation. There were no correlations between PPI, post-stimulation iANI, and SCA-derived variables. There were no differences in PPI, iANI, and SCA variables in patients with low and normal baseline EEG power at baseline. PerspectivesDetection of nociception varies across different devices in unconscious critically ill patients. Further studies are required to understand which method to implement for analgesic administration in this patient population.

Research on Ecological Landscape Design and Healing Effect Based on 3D Roaming Technology.

Impacted by the COVID-19 epidemic, the human sub-health in national high-tech zones (hereinafter referred to as high-tech zones) has become more prominent. It is critical for the mental sub-health group in the high-tech zone to relieve the anxiety and tension caused by the pressure of life and work. This paper uses SketchUp virtual engine (Unity 2019) software, and 3D roaming technology to carry out the ecological landscape transformation design of the Baotzixi ecological corridor in the East Lake High-tech Zone, to construct a 3D roaming landscape scene and measure its therapeutic effect by inviting subjects to participate in an interactive experience experiment on the ErgoLAB platform. The results illustrate that: (1) the thermogram trend shows that the more attractive the 3D roaming landscape scene is, the stronger the subjects’ interest is; (2) the participants have a positive emotional arousal state in the immersive experience of the 3D roaming landscape scene after the modification design; and (3) the mean skin conductance (SC) fluctuation variance of the subjects is 5.819%, indicating that the healing effect is significant in the state of positive emotional arousal. The research results show that there is a connection between the subjects and the 3D roaming landscape scene after the transformation design of “high interest, emotional arousal and significant healing”.

Colour Preference and Healing in Digital Roaming Landscape: A Case Study of Mental Subhealth Populations.

From the perspective of emotional preference, studies have been conducted about landscape healing for subhealth people in the National High-Tech Zone (the study area). Combined with a preliminary practice investigation, Unity 2019 was used to make a digital roaming landscape, and 91 subjects with a history of mental subhealth diseases were randomly invited to participate in the immersive experimentation of the Human–Machine Environment Synchronisation (ErgoLAB) platform. After the experiment, the subjects were invited to fill in a Likert scale as the control group. The interest preference, emotion fluctuation, and healing effect of landscape colour were verified. The results show that: (1) The variation trend of interest reflected the concentration of interest in landscape, and the order of degree of interest, ranging from high to low, went Green > Yellow > Blue > Red > Orange > Purple > Cyan. (2) The subjects’ interest in landscape colour was correlated with the arousal of positive emotions. The correlation between interest in landscape colour and positive emotions, from high to low, went Blue > Green > Yellow, while the correlation between red, cyan, orange, and purple was not significant. (3) The mean skin conductance (SC) fluctuation variance of subjects was 5.594%, which confirmed that the healing effect of digital roaming landscape scenes was significant under the state of low arousal. According to the Likert scale data, subjects’ scores of the healing effect of landscapes, from high to low, went as follows: Green > Yellow > Red > Blue > Cyan > Orange > Purple. The results provide a new method for demonstrating the logical relationship between the digital landscape interest experience–emotional awakening–healing effect and providing a theoretical method and construction scheme for landscape colour configuration in the implementation of landscape healing projects.

Correlation between skin conductance measurements and subjective pain scales in children after otolaryngological procedures

Abstract Introduction Pain assessment in children is crucial in managing postoperative analgesia; it is therefore necessary to determine the most accurate tool for assessing pain in children. The aim of this study was to evaluate the correlation between skin conductance measurements and self-reporting pain scales in children after otolaryngology procedures. Materials and methods Thirty-three children (N=33) were assessed for eligibility for the research. Postoperative pain was assessed using the Visual Analogue Scale; the Wong-Baker Faces Pain Rating Scale; the Face, Legs, Activity, Cry, and Consolability scale; and a skin conductance algesimeter. The postoperative pain was measured 1 and 2 hours after the surgery. Results There was no statistically significant correlation between self-reported pain scores and the skin conductance fluctuations in the children studied, regardless of gender or age. A statistically significant correlation was found between the existing subjective pain scales in children. Conclusions The skin conductance measurements do not provide an additional reliable tool for assessing pain in patients after otolaryngological procedures. The existing self-reported pain scales are sufficient to assess postoperative pain in children.

Increased body sway in phobic patients exposed to images of spiders.

Objective:The aim of the present study was to analyze the body sway response in specific phobia (SP) patients and healthy controls while viewing neutral, phobic, and disgusting images.Methods:The participants’ heart rate (HR) and skin conductance were also recorded during the procedure. Nineteen patients with arachnophobia and 19 healthy volunteers matched by age, gender, and years of education underwent a postural control test on a stabilometric platform.Results:The platform recorded increased body sway in the SP group when exposed to spider images (SPI). The SP group presented increases in most parameters (SD, velocity, frequency, area, p ≤ 0.05) when viewing pictures of the SPI category. Psychometric measures of subjective anxiety (State-Trait Anxiety Inventory, STAI) and physiological states (HR; skin conductance responses; spontaneous fluctuations in skin conductance) showed increased anxiety (p ≤ 0.05) in the SP group compared to healthy volunteers. High anxiety levels were observed throughout the assessment, including the task of exposure to SPI (p ≤ 0.05). No significant effect or correlation was found between skin conductance and body sway measures (p > 0.05).Conclusions:The results of the postural control test suggest the occurrence of a defensive escape response in SP, in agreement with previous evidence.

Normalized skin conductance level could differentiate physical pain stimuli from other sympathetic stimuli

Skin conductance monitoring is one of the promising methods for objectively evaluating pain. However, skin conductance might possibly increase in response to sympathetic stimulation other than pain. In this study, we aimed to test whether skin conductance monitoring can distinguish physical pain stimulation (heat, mechanical and cold stimulation) from other sympathetic stimuli (stimulation by noise and painful images). Twenty-three healthy volunteers participated in this prospective observational study. The number of fluctuations in skin conductance (NFSC) and normalized skin conductance level (nSCL) were measured and compared with pain scores on a self-reported pain scale (numerical pain scale [NPS]). Both NFSC and nSCL increased during mechanical stimulation. Further, nSCL, but not NFSC, well reflected heat stimulus intensity, suggesting its ability to quantitatively evaluate pain. nSCLs during physical pain stimulation were greater than those during other sympathetic stimulations. However, NFSC was not able to completely distinguish between the stimuli. These results suggest that nSCL could better differentiate physical pain stimuli from other sympathetic stimuli than NFSC. In comparisons between subjective and objective pain assessment in the same individual, nSCL correlated better with NPS score, indicating the possibility of being able to monitor the transition of pain. Monitoring changes in skin conductance using nSCL might be useful for objectively detecting physical pain.

Sympathetic and Parasympathetic Modulation of Pupillary Unrest.

Pupillary unrest is an established indicator of drowsiness or sleepiness. How sympathetic and parasympathetic activity contribute to pupillary unrest is not entirely unclear. In this study, we investigated 83 young healthy volunteers to assess the relationship of pupillary unrest to other markers of the autonomic nervous system. Sample entropy (SE) and the established pupillary unrest index (PUI) were calculated to characterize pupil size variability. Autonomic indices were derived from heart rate, blood pressure, respiration, and skin conductance. Additionally, we assessed individual levels of calmness, vigilance, and mood. In an independent sample of 26 healthy participants, we stimulated the cardiovagal system by a deep breathing test. PUI was related to parasympathetic cardiac indices and sleepiness. A linear combination of vagal heart rate variability [root mean square of heart beat interval differences (RMSSD)] and skin conductance fluctuations (SCFs) was suited best to explain interindividual variance of PUI. Complexity of pupil diameter (PD) variations correlated to indices of sympathetic skin conductance. Furthermore, we found that spontaneous fluctuations of skin conductance are accompanied by increases of pupil size. In an independent sample, we were able to corroborate the relation of PUI with RMSSD and skin conductance. A slow breathing test enhanced RMSSD and PUI proportionally to each other, while complexity of PD dynamics decreased. Our data suggest that the slow PD oscillations (f < 0.15 Hz) quantified by PUI are related to the parasympathetic modulation. Sympathetic arousal as detected by SCFs is associated to transient pupil size increases that increase non-linear pupillary dynamics.

Pain assessment during eye examination for retinopathy of prematurity screening: Skin conductance versus PIPP-R.

To assess changes in skin conductance during retinopathy of prematurity screening and to study the correlation between the skin conductance and a validated pain scale. Prospective observational study. Fifty-three eye examinations were performed in 32 preterm infant candidates for retinopathy of prematurity screening. Outcome measures were changes in Premature Infant Pain Profile-Revised (PIPP-R) scale and number of skin conductance fluctuations. There was a significant increase from baseline in the number of skin conductance fluctuations and PIPP-R during the procedure. The maximum value of number of skin conductance fluctuations was 0.64±0.44 peaks/sec, and the maximum value of PIPP-R was 10.8±3.3. A correlation between the skin conductance and PIPP-R was not found at any time during the eye examination. Repeated measures correlation analyses showed only a moderate positive correlation between PIPP-R and number of skin conductance fluctuation values. There were significant changes in both PIPP-R and number of skin conductance fluctuations during retinopathy of prematurity screening, reaffirming that this procedure is painful and stressful. The number of skin conductance fluctuations and PIPP-R are not significantly correlated, which likely reflects that these parameters evaluate different but complementary aspects of neonatal pain responses.

The relation of skin conductance and pupillary fluctuations assessed by phase-rectified signal averaging.

The reaction of pupil diameter and skin conductance are widely studied marker of the autonomic response to arousing stimuli. However, little is known about their relation at rest. In this study, we used bivariate phase-rectified signal averaging to investigate the relationship of skin conductance fluctuations (SCF) and pupillary fluctuations in 83 healthy volunteers. The onset of each SCF was detected by a pattern matching algorithm. Those time points were corrected for a different neurotransmission delay. Cross-correlation of temporal derivatives of pupil diameter and skin conductance revealed an average time lag of 2.5s. Thus, anchor points 2.5s before an SCF were defined. The pupillary signal following these anchors (7s) were extracted and normalized to baseline 1s prior to the anchor point. Aligned segments were averaged to determine the amplitude and area under the curve (AUC) of characteristic pupil diameter fluctuations (PDF) concurrent to SCF. The same procedure was applied to random time points (non-SCF) with at least 1s distance to actually detected SCF which served as control condition. SCF were accompanied by increases of pupil diameter with a maximum dilation of 9% on average. The one sample t-test indicated an AUC of PDF (70 ± 110 n.u., p<; 0.001). The maximum change and AUC of pupillary reactions were significantly higher when PDF extraction was triggered by actual SCF (both p<; 0.001). Both measures of pupillary dilations contributed significantly to pupillary unrest. Our results suggest that sympathetic arousal as detected by skin conductance fluctuations is accompanied by pupil dilation.

Differences of sympathetic and parasympathetic modulation in major depression

Inconsistent results have been reported with respect to cardiac autonomic function in major depression. The aim of our study was to investigate autonomic function in various branches of the autonomic nervous system in order to better understand parasympathetic and sympathetic modulation in the disease.We investigated 29 unmedicated patients suffering from major depression (MD) in comparison to matched control subjects (gender, age, BMI). The autonomic assessment at rest included values of heart rate variability (HRV), blood pressure variability (BPV), baroreflex sensitivity (BRS), respiration, skin conductance (SC) as well as the calculation of pupillary diameter and the unrest index (PUI). Results were compared by means of a multivariate analysis of variance. In a classification analysis, we identified suitable parameters for patient - control separation. Finally, to analyze interrelations of pupillometric parameters and autonomic indices, we estimated Pearson correlation coefficients and fitted a linear regression model.Apart from a significantly increased heart rate (75±12 vs. 65±6min−1, p<0.001) and decreased BRS (14±13 vs. 20±15ms/mmHg, p<0.05), we observed a lack of significant differences in HRV and BPV analysis between patients and controls. However, pupillary diameter (left: 4.3±0.9 vs. 3.8±0.6, p<0.01; right: 4.3±0.9 vs. 3.7±0.6mm, p<0.01) and PUI (left: 14.8±6.0 vs. 10.7±4.5mm/min, p<0.01; right: 14.1±5.5 vs. 10.7±4.8mm/min, p<0.01), as well as the level (left: 7.3±6.2 vs. 4.3±4.4 μS, p<0.05) and fluctuations of skin conductance (left: 4.2±4.1 vs. 2.5±3.6, p<0.05; right: 4.2±4.4 vs. 2.6±3.2, p<0.05) were significantly different. The classification accuracy was 88.5% with high specificity (e=92.9%) and sensitivity (s=83.3%) including heart rate, PUI and skin conductance. HRV indices correlated to PUI in controls but not in patients.Our data add evidence to the current debate on autonomic function in major depression. We suggest that diverse results are mainly caused by methodological shortcomings, in particular by the application of HRV assessment only, which misses changes of sympathetic modulation. The application of broader analyzing tools will clarify the pattern of autonomic function in depression and ultimately its role in cardiac morbidity and mortality.

The relation between skin conductance responses and recovery from symptoms of PTSD.

The purpose was to investigate if potentially stressful reminders of the intensive care unit (ICU) stay influenced variability in transient skin conductance responses, and whether such changes were associated with post-traumatic stress symptoms (PTSS), and development of symptoms over time. Thirty patients with an ICU length of stay > 48 h were included in the study. Within the week after ICU discharge (T1), patients were exposed to authentic ICU sound and questions regarding traumatic ICU memories while skin conductance reactivity was monitored. PTSS was assessed using PTSS-10 at T1 and again 3 months later (T2). Changes in number of skin conductance fluctuations per second (NSCF) between baseline and during the cueing conditions and in relation to PTSS scores (T1) were investigated. PTSS scores at T2 and changes between T1 and T2 (PTSS-CS) were used to investigate if reactivity in NSCF could predict symptoms of PTSD. The results showed increases in NSCF during both situational and verbal cueing, compared to baseline. However, no relation to PTSS scores was indicated. Negative correlations between NSCF during situational cueing and both PTSS-T2 and PTSS-CS were found among women, but not among men. A low variability, or reactivity in skin conductance responses to situational cues could imply a risk of developing, or not being able to recover from, symptoms of PTSD in women. As such, the measurement could be used to predict this risk in women. However, further studies are necessary to evaluate this area of application.

Interoception in pathological health anxiety.

According to cognitive-behavioral models, pathological health anxiety is triggered and maintained by the perception of mostly mild and benign bodily sensations that are misinterpreted as signs of illness. Arguably, abnormalities in interoception may account for this misguided preoccupation with somatic sensations. Using a multimethod approach, the current study investigated possible abnormalities in interoception in patients with pathological health anxiety (PHA; n = 51) and healthy participants (n = 56). Different types of interoception were assessed with a heartbeat-tracking task and a signal-detection task for nonspecific skin conductance fluctuations (NSCFs task). Patients compared with healthy participants showed a more liberal interoceptive response bias for NSCFs, t(79) = 2.32, p = .02, d = 0.53, 95% confidence interval (CI) (0.30, 0.68). Specifically, patients with a comorbid anxiety disorder compared with healthy participants exhibited a significantly higher interoceptive sensitivity for NSCFs, t(57) = 3.12, p < .01, d = 0.89, 95% CI (0.54, 1.12). No evidence for higher interoceptive sensitivity in PHA (neither in the heartbeat mental tracking task nor in the NSCF task) was observed after accounting for comorbid anxiety disorders. The findings suggest that higher interoceptive sensitivity might not be specific to health anxiety, but rather associated with factors shared with the anxiety disorders. Biased (i.e., more liberal) interoceptive processing appears more specific to health anxiety, but further studies using larger sample sizes and a multimethod approach for the assessment of interoception are needed to more completely unravel the role of interoception in health anxiety. (PsycINFO Database Record

Pain rather than induced emotions and ICU sound increases skin conductance variability in healthy volunteers.

Assessing pain in critically ill patients is difficult. Skin conductance variability (SCV), induced by the sympathetic response to pain, has been suggested as a method to identify pain in poorly communicating patients. However, SCV, a derivate of conventional skin conductance, could potentially also be sensitive to emotional stress. The purpose of the study was to investigate if pain and emotional stress can be distinguished with SCV. In a series of twelve 1-min sessions with SCV recording, 18 healthy volunteers were exposed to standardized electric pain stimulation during blocks of positive, negative, or neutral emotion, induced with pictures from the International Affective PictureSystem (IAPS). Additionally, authentic intensive care unit (ICU) sound was included in half of the sessions. All possible combinations of pain and sound occurred in each block of emotion, and blocks were presented in randomized order. Pain stimulation resulted in increases in the number of skin conductance fluctuations (NSCF) in all but one participant. During pain-free baseline sessions, the median NSCF was 0.068 (interquartile range 0.013-0.089) and during pain stimulation median NSCF increased to 0.225 (interquartile range 0.146-0.3175). Only small increases in NSCF were found during negative emotions. Pain, assessed with the numeric rating scale, during the sessions with pain stimulation was not altered significantly by other ongoing sensory input. In healthy volunteers, NSCF appears to reflect ongoing autonomous reactions mainly to pain and to a lesser extent, reactions to emotion induced with IAPS pictures or ICU sound.

Preliminary Intraoperative Validation of the Nociception Level Index: A Noninvasive Nociception Monitor.

The nociception level (NoL) index is an index of nociception based on nonlinear combination of heart rate, heart rate variability, photoplethysmograph wave amplitude, skin conductance, skin conductance fluctuations, and their time derivatives. The authors evaluated the abilities of the NoL index and other measures of nociception to discriminate between noxious and nonnoxious stimuli, to progressively respond to graded stimuli, and to respond to opioid administration. Intraoperative NoL was compared to heart rate, pulse plethysmograph amplitude, noninvasive blood pressure, and the surgical pleth index around five specific stimuli: tetanic stimulation with and without fentanyl analgesia, intubation, first incision/trocar insertion, and a nonnoxious period. The response around first incision was analyzed at two target plasma concentrations of remifentanil. In 58 patients, the NoL index responded progressively to increased stimulus intensity and remained unchanged in response to nonnoxious stimuli. Compared to other accepted measures of nociception, the NoL index better discriminated noxious from nonnoxious stimuli with an area under the curve of 0.93 (95% CI, 0.89 to 0.97) and a sensitivity of 87% at a specificity of 84%. The NoL index was the only measure that reliably reflected two different analgesic concentrations of remifentanil during initial skin incision or trocar insertion. The NoL index changes proportionately with patients' response to various clinical and experimental noxious stimuli and discriminates noxious from nonnoxious stimuli with high sensitivity and specificity. The NoL index also responds progressively to increasing stimuli intensity and is appropriately blunted by analgesic administration. The NoL index was superior to other compared measures and appears to accurately characterize nociception during general anesthesia.

Skin conductance in neonates suffering from abstinence syndrome and unexposed newborns.

The aims of this study were to compare the skin conductance (SC) of newborns with opiate-induced neonatal abstinence syndrome (NAS) to that of unexposed newborns and to evaluate the potential of SC readings to detect distress in the context of NAS objectively. The SC of 12 newborns with NAS and 12 unexposed newborns was measured at nine specific times during their first 6weeks of life. The number of SC fluctuations per second (NSCF/s), the amplitude of SC fluctuation, and the mean level of SC were recorded and analyzed. The SC of newborns treated for symptoms of NAS differed significantly from the SC of unexposed newborns with regard to the NSCF/s (p = 0.04). With the mean level of SC, we observed an interaction between groups over time (p value for interaction = 0.02). With increasing postnatal age, we observed higher values in all three SC parameters. The NSCF/s and the mean level of SC appear to be suitable to reflect the distress of newborns suffering from NAS. As it is known that the sensitivity of SC increases with the level of stress experienced, its potential to indicate elevated stress levels in infants with NAS should be investigated in future studies evaluating different therapy regimens. • Skin conductance is a result of the filling of palmar and plantar sweat glands innervated by the sympathetic nervous system • Skin conductance can be used as a measure of stress and pain in newborns What is New: • Skin conductance of newborns with neonatal abstinence syndrome (NAS) differs significantly from the SC of non-substance-exposed newborns during the first 6weeks of life • Skin conductance appears to reflect the increased distress of infants with NAS.

The Skin Conductance Algesimeter validated with the Numerical Rating Scale postoperatively in patients treated with classical music

Background: An inadequate estimation and management of perioperative pain may delay patient recovery and discharge from hospital. The aim of this study was to evaluate the efficacy of the skin conductance algesimeter index - number of skin conductance fluctuations (NSCF) per second , as compared to the Numerical Rating Scale (NRS), in perioperative pain monitoring of thyroidectomy patients for patients listening to classical music.Methods: Forty patients scheduled for surgical thyroidectomy were randomized into two groups with partially different postoperative managements: Group C (Control) received the traditional treatment, while Group S (Study) had classical music in addition to the traditional treatment. In both groups, the postoperative pain levels were assessed using NSCF per second, NRS and self-administrated analgesic drug consumption.Results: The C and S groups were characterized by similar levels of pain as measured by NRS and NSCF per second. The S group used less morphine than the C group (0.3 mg vs. 1.1 mg; P < 0.01). We also observed a significant correlation between NRS and NSCF per second when 30 minute time intervals between measurements were used (R = 0.69, P < 0.01). On the other hand no correlation was observed when moment-by-moment measurements were used. Both the NRS and NSCF per second decreased significantly during the postoperative period.Conclusion: The NRS and NSCF per second performed similarly for pain assessment in the postoperative period. Classical music listening in addition to traditional treatment reduced the morphine consumption without clearly influencing the pain level as measured by NRS and NSCF per second.

Ability of the nociception level, a multiparameter composite of autonomic signals, to detect noxious stimuli during propofol-remifentanil anesthesia.

A novel multidimensional index of nociception, the nociception level (NoL) index, derived from the nonlinear composite of heart rate (HR), HR variability, amplitude of the photoplethysmogram, skin conductance, fluctuations in skin conductance, and their time derivatives, was used to assess nociception during anesthesia. Seventy-two American Society of Anesthesiologists I to III patients received propofol (target bispectral index, 45) and one of six remifentanil target concentrations in the range of 0 to 5 ng/ml. The NoL, mean arterial pressure (MAP; derived from a beat-to-beat finger cuff measurement), and HR were measured during nonnoxious, moderate noxious (skin incision), and intense noxious (intubation) stimulation. Values are represented as average (95% CI). NoL, HR, and MAP did not change during nonnoxious events. Incision increased HR by 1.3/min (-0.46 to 3.1/min; not significant), MAP by 7.9 mmHg (-1.9 to 13.0 mmHg; not significant), and NoL by 8.0 (0.4 to 16.0; P < 0.001). Intubation increased HR by 7.0/min (1.4 to 12.0/min; P < 0.001), MAP by 13.0 mmHg (3.1 to 20 mmHg; P < 0.001), and NoL by 18.0 (7.8 to 29.0; P < 0.001). The ΔNoL area under the curve (0.95) of the receiver operating characteristic curve was greater compared with ΔHR (0.84, P < 0.001) and ΔMAP (0.78, P < 0.001). Under nonnociceptive conditions, remifentanil had no effect on NoL, in contrast to HR and MAP that showed a dose-dependent decrease. The NoL is a reliable measure of moderate and intense noxious stimulation and outperforms HR and MAP in differentiating noxious from nonnoxious stimuli. In contrast to HR and MAP, the NoL was not affected by hemodynamic effects of remifentanil.