The Relationship between Numbness and Quality of Life

BACKGROUND

Numbness is a term commonly used in clinical practice to describe an abnormal sensory experience that is produced by a stimulus or is present even without a stimulus. However, there is still much that remains obscure in this field, and also, few reports have focused on its symptoms. In addition, while pain itself is known to have a significant impact on quality of life (QOL), the relationship between numbness and QOL is often unclear. Therefore, we conducted an epidemiological survey and analyzed the relationship between painless numbness and QOL, using type, location, and age as influencing factors, respectively.

METHODS

A nationwide epidemiological survey was conducted by mail using a survey panel designed by the Nippon Research Center. Questionnaires were sent to 10,000 randomly selected people aged 18 and over from all over Japan. Out of the 5682 people who responded, the relationship between numbness and QOL was analyzed using the EuroQol 5 Dimension-3L (EQ5D-3L) for patients who are currently experiencing painless numbness.

FINDINGS

The results suggest that painless numbness affects QOL and that QOL decreases as its intensity increases. Furthermore, the two factors of numbness of feet and numbness among the young may be less likely to affect QOL. This study may be of great significance in the field of numbness research.

The Addition of a Head Rotation When the Ramped Position Fails to Provide Good Laryngeal Visualization: A Preliminary Study

Although several studies have reported that the ramped position (torso and head elevated) significantly improves laryngoscopic view, in our experience, the ramped position fails to provide good laryngeal visualization in some cases. When the ramped position failed to provide good laryngeal visualization, we added a head rotation in order to improve laryngeal visualization in 62 patients. The method significantly improved laryngeal visualization and did not cause laryngeal disturbances postoperatively.

Analysis of follow-up data from an outpatient pain management program for refractory chronic pain

BACKGROUND

Numerous reports indicate that multifaceted pain management programs based on cognitive-behavioral principles are associated with clinically meaningful long-term improvements in chronic pain. However, this has not yet been investigated in Japan. This study investigated the effects of a multifaceted pain management program in Japanese patients with chronic pain, both immediately after the program and 6 months thereafter.

METHODS

A total of 96 patients, 37 male and 59 female (mean age 63.8 years) experiencing treatment difficulties and suffering from intractable pain for more than 6 months were enrolled in the study. The programs were conducted with groups of 5-7 patients who met weekly for 9 weeks. Weekly sessions of approximately 2 h in duration incorporating a combination of lectures and exercise were conducted. Several measures related to pain and physical function were assessed at the start of the program, the end of the program, and 6 months after completion of the program. The resulting data were analyzed via Wilcoxon signed-rank test, and 'r' estimated by effect size was also assessed.

RESULTS

Of the 96 initial participants, 11 dropped out during the program and 85 completed it. Thereafter, we evaluated 62 subjects at 6 months after the program, while 23 could not be evaluated at that time-point. Pain intensity upon moving, catastrophizing scores, and pain disability scores showed good improvements at the 6-month follow-up, with large efficacy (r > 0.5). Moving capacity and 6-min walking distance also showed good improvements with large efficacy, both at the end of the program and at the 6-month follow-up (r > 0.5).

CONCLUSIONS

A multifaceted pain-management program based on cognitive-behavioral principles was effective in Japanese patients with chronic pain, resulting in improved long-term clinical outcomes.

Prevalence, characteristics, and burden of failed back surgery syndrome: the influence of various residual symptoms on patient satisfaction and quality of life as assessed by a nationwide Internet survey in Japan

We conducted a cross-sectional, Internet-based survey with a nationally representative sample of Japanese adults to assess the prevalence and characteristics of failed back surgery syndrome (FBSS). Data regarding the residual symptoms and patient satisfaction from an online survey of 1842 lumbar surgery patients revealed the prevalence of FBSS to be 20.6% (95% confidence interval [CI], 18.8–22.6). The prevalence of low back pain, dull ache, numbness, cold sensations, and paresthesia after surgery was 94.0%, 71.1%, 69.8%, 43.3%, and 35.3%, respectively. With a logistic regression model, severe residual low back pain (numerical rating scale 8–10), higher pain intensity, and multiple low back surgeries were strongly associated with FBSS, with odds ratios of 15.21 (95% CI, 7.79–29.7), 1.40 (95% CI, 1.32–1.49), and 1.87 (95% CI, 1.25–2.81), respectively. Respondents with FBSS had significantly lower EuroQol-5D (P<0.001) values and significantly higher scores on the Kessler six-item psychological distress scale (P<0.001), compared with the non-FBSS group. Our findings indicate that residual sensations have a significant effect on patient quality of life, similar to that of chronic low back pain. Precise presurgical provision of prognoses based on comprehensive epidemiologic data, as well as scrupulous attention to patient satisfaction and clinical progress may help reduce the incidence of FBSS.

The Use of a Stylet to Aid the Lifting of the Epiglottis With a Video Laryngoscope

This study involved 154 anesthetized patients requiring endotracheal intubation, in whom the epiglottis was visible but not lifted, which restricted the view of the glottis. A simple stylet was used to lift the epiglottis, thus improving the view of the glottis with the Glide Scope®, allowing tracheal tubes to be inserted into the patients. The stylet easily resolved the difficulty of lifting the epiglottis when using a video laryngoscope, thus facilitating endotracheal intubation in patients undergoing general anesthesia.

Severe Respiratory Event Initially Thought to be Inadvertent Endobronchial Intubation: Possible Complications From Using of a Topical Metered-Dose of 8% Lidocaine Pump Spray

INTRODUCTION

Pulmonary collapse after intubation is common, and it is caused by a variety of factors.

CASE PRESENTATION

A 21-year-old man presented at our operation room to undergo an appendectomy. Except for a history of cigarette smoking, his history was negative. Anesthesia was induced with 100% oxygen and sevoflurane, remifentanil infusion, and propofol. Neuromuscular block was obtained with rocuronium. The tip and cuff of a tracheal tube were lubricated with a topical metered-dose of 8% Lidocaine pump spray. After intubation, SPO2 suddenly decreased. The chest x-ray revealed right upper lobe atelectasis. Fiber optic bronchoscopy showed that a large amount of yellow sticky mucus had been secreted into the right main bronchus.

CONCLUSIONS

In Japan, 8% Lidocaine pump spray contains menthol and ethanol as additives. These additives, particularly menthol, might have led to excessive mucus production, although we did not analyze the mucus secretion.

The Lateral Position Improved Airway Patency in Anesthetized Patient With Burn-Induced Cervico-Mento-Sternal Scar Contracture

A 78-year-old woman with burn-induced cervico-mento-sternal scar contracture was scheduled for laparoscopic cholecystectomy. During inhalational induction of sevoflurane, her airway patency deteriorated. The right lateral position and assist ventilation using a breathing bag dramatically improved her airway patency.

Locomotive syndrome is associated not only with physical capacity but also degree of depression

BACKGROUND

Reports of locomotive syndrome (LS) have recently been increasing. Although physical performance measures for LS have been well investigated to date, studies including psychiatric assessment are still scarce. Hence, the aim of this study was to investigate both physical and mental parameters in relation to presence and severity of LS using a 25-question geriatric locomotive function scale (GLFS-25) questionnaire.

METHODS

150 elderly people aged over 60 years who were members of our physical-fitness center and displayed well-being were enrolled in this study. Firstly, using the previously determined GLFS-25 cutoff value (=16 points), subjects were divided into two groups accordingly: an LS and non-LS group in order to compare each parameter (age, grip strength, timed-up-and-go test (TUG), one-leg standing with eye open, back muscle and leg muscle strength, degree of depression and cognitive impairment) between the groups using the Mann-Whitney U-test followed by multiple logistic regression analysis. Secondly, a multiple linear regression was conducted to determine which variables showed the strongest correlation with severity of LS.

RESULTS

We confirmed 110 people for non-LS (73%) and 40 people for LS using the GLFS-25 cutoff value. Comparative analysis between LS and non-LS revealed significant differences in parameters in age, grip strength, TUG, one-leg standing, back muscle strength and degree of depression (p < 0.006, after Bonferroni correction). Multiple logistic regression revealed that functional decline in grip strength, TUG and one-leg standing and degree of depression were significantly associated with LS. On the other hand, we observed that the significant contributors towards the GLFS-25 score were TUG and degree of depression in multiple linear regression analysis.

CONCLUSIONS

The results indicate that LS is associated with not only the capacity of physical performance but also the degree of depression although most participants fell under the criteria of LS.

Higher pain rating results in lower variability of somatosensory cortex activation by painful mechanical stimuli: An fMRI study

OBJECTIVE

The aim of this study was to find pain-related brain activity which corresponds to self-report pain ratings based on degree of response and repeatability.

METHODS

Three painful mechanical stimuli were applied to the right hands of 25 healthy volunteers using monofilaments (forces of 0.98N, 2.94N, and 5.88N). Simultaneously, brain activities were evaluated using functional MRI for a constant stimulus conducted three times in a session. In first assessment, the average percent signal change (PSC) of neuronal response was measured for each region of interest (ROI), secondary repeatability of PSC conducted three times over the session was evaluated for each ROI.

RESULTS

Although the average PSCs for trice stimuli conducted in one session increased in accordance with pain ratings in the somatosensory cortex (S1) and anterior cingulate cortex (ACC), there was a different response between S1 and ACC when subjects rated intense pain; a stable response in S1 against a variable response in ACC.

CONCLUSIONS

These results imply that there are different cognitive responses between sensory discrimination and affective component to constant painful stimulus each time.

SIGNIFICANCE

Consistency of brain activity based on PSC may be an important biomarker which, along with its neuronal activity, gauges self-report pain ratings.

Predictive factors for the outcome of multidisciplinary treatments in chronic low back pain at the first multidisciplinary pain center of Japan

[Purpose] Multidisciplinary treatments are recommended for treatment of chronic low back pain. The aim of this study was to show the associations among multidisciplinary treatment outcomes, pretreatment psychological factors, self-reported pain levels, and history of pain in chronic low back pain patients. [Subjects and Methods] A total of 221 chronic low back pain patients were chosen for the study. The pretreatment scores for the 10-cm Visual Analogue Scale, Hospital Anxiety and Depression Scale, Pain Catastrophizing Scale, Short-Form McGill Pain Questionnaire, Pain Disability Assessment Scale, pain drawings, and history of pain were collected. The patients were divided into two treatment outcome groups a year later: a good outcome group and a poor outcome group. [Results] One-hundred eighteen patients were allocated to the good outcome group. The scores for the Visual Analogue Scale, Pain Disability Assessment Scale, and affective subscale of the Short-Form McGill Pain Questionnaire and number of nonorganic pain drawings in the good outcome group were significantly lower than those in the poor outcome group. Duration of pain in the good outcome group was significantly shorter than in the poor outcome group. [Conclusion] These findings help better predict the efficacy of multidisciplinary treatments in chronic low back pain patients.

Dorsal root ganglion pulsed radiofrequency for the management of intractable vertebral metastatic pain: a case series

OBJECTIVE

Metastatic bone pain is characteristic of cancer pain and is a form of refractory cancer pain, as the pain includes not only nociceptive but also neuropathic pain. Although some drugs are effective in the management of painful bone metastases, pain while moving is one of the most refractory forms of pain. Although pulsed radiofrequency (RF) dramatically reduces neuropathic pain, chronic pain, and vertebral metastatic pain, the number of cases reported in these studies was very small (five or less).

DESIGN

Case report.

SETTING

Single pain center.

PATIENTS

Fifteen patients suffering from intractable vertebral metastatic pain.

INTERVENTIONS

Dorsal root ganglion (DRG) pulsed RF.

OUTCOME MEASURES

A numerical rating scale (NRS) of pain at rest and while moving.

RESULTS

Almost all patients experienced sound pain relief after the pulsed RF treatment. There were no severe side effects reported.

CONCLUSION

DRG pulsed RF procedure provided sound pain relief for patients with intractable vertebral metastatic pain. Metastatic bone pain is characteristic of cancer pain and is a form of refractory cancer pain, as the pain includes not only nociceptive but also neuropathic pain. Although some drugs are effective in the management of painful bone metastases, pain while moving is one of the most refractory forms of pain. DRG pulsed RF procedure provided sound pain relief for patients with intractable vertebral metastatic pain.

Regional differences of repeatability on visual analogue scale with experimental mechanical pain stimuli

Pain-VAS is quite subjective as a scale, but has a tendency to assume differences in repeatability in accordance with perceived pain intensity. The aim of the present study was to investigate the repeatability of regional differences with ratings of pain-VAS. Three experimental mechanical stimuli were applied to twenty seven healthy volunteers across four sessions over four weeks within individuals. The same stimuli were also simultaneously measured in the same manner with an electric balance. The magnitude of mechanical stimuli was determined by 100 g, 300 g, and 600 g monofilaments. Standard deviations (SDs) across measurements with an electric balance showed a regular increase with stimulus magnitude, while coefficient variations (CVs) were constant in each stimulus. On the other hand, although SDs across pain-VAS measurements were significantly greater with the 300 g filament than with the 100 g and 600 g filaments, CVs showed a regular decrease in magnitude of stimulus. These results showed that the CVs of repeated measurement with electric balance were consistent regardless of stimulus intensity, in contrast, CVs of pain-VAS decreased with greater pain rating averaged by repeated measurement. These results suggest that a low rating in pain-VAS is inherently less objective, indicating poor repeatability. In contrast, a high rating in pain-VAS is more objective with better repeatability for experimental pain perception.

The review of innovative integration of Kampo medicine and Western medicine as personalized medicine at the first multidisciplinary pain center in Japan

Background

The Japanese medical system is unique because it is the only country in the world where Western medicine and traditional Japanese medicine including Kampo medicine, traditional Japanese herbal medicine, are used in our daily clinical practice. Pain is essentially an interactive psychophysiological behavior pattern. Thus, an interdisciplinary approach is often recommended in providing appropriate therapeutic care for the patients suffering from chronic and intractable pain. In addition, we have been prescribing Kampo medicines in combination with Western medicines as personalized medicine in order to treat patients with chronic pain at our pain center. The aim of our study was to conduct a survey on the current use and the effect of Kampo medicines in our multidisciplinary pain center.

Methods

Retrospective analysis was performed on 221 out of 487 patients suffering from chronic pain.

Results

The most frequent medical complaints for which Kampo medicines were prescribed were lower back/lower limb pain, neck/upper limb pain, various facial pains, headache/migraine, whiplash-associated disorder, and frozen shoulder. Kampo medicines were prescribed based on patient-centered Kampo diagnosis. Moreover, several Kampo medicines generally for the management of psychological symptoms were prescribed for about 70% of the patients. Pain improvement in the patients was categorized as follows: 26.3% with marked improvement, 12.7% with moderate improvement, 38.9% with some improvement, and 19.9% with no improvement.

Conclusions

Two thirds of the chronic pain patients with the use of Kampo medicines combined with Western medicine experienced further pain improvements.

Combinations of low-dose antidepressants and low-dose pregabalin as useful adjuvants to opioids for intractable, painful bone metastases

BACKGROUND

Systemic analgesics would not provide good enough pain relief for some kinds of cancer pain. Metastatic bone pain is characteristic of one of the refractory cancer pains, since the pain is not only nociceptive but also neuropathic. A low-dose antiepileptic-antidepressant combination with opioids is effective in the management of neuropathic cancer pain.

OBJECTIVE

The aim was to see whether a low-dose antiepileptic-antidepressant combination is effective in the treatment of bone metastases.

STUDY DESIGN

Randomized, controlled trial.

SETTING

Pain Clinic in Japan.

METHODS

Thirty-seven cancer patients, confirmed to have bone metastases, were allocated into 3 groups: P group took pregabalin 50 mg every 8 hours orally; P-I group took pregabalin 25 mg every 8 hours orally and imipramine 5 mg every 12 hours orally; P-M group took pregabalin 25 mg every 8 hours orally and mirtazapine 7.5 mg every 12 hours orally. Pain assessments were performed for 2 weeks.

RESULTS

The total pain score significantly decreased in all 3 groups even one day after the start of the medication. The decreases in the P-I and P-M groups were significantly greater than those in the P group from Day 2. Also, the daily paroxysmal pain episodes significantly decreased in all 3 groups at Day one. The decreases in the P-M groups were significantly greater than those in the P group from Day one. The decreases in the P-I group were significantly greater than those in the P group from Day 3.

CONCLUSION

Low-dose pregabalin-antidepressant combinations with opioids were effective in the management of painful bone metastases.

Intravenous lidocaine and magnesium for management of intractable trigeminal neuralgia: a case series of nine patients

Most patients suffering from trigeminal neuralgia (TN) benefit from medical therapy, for example carbamazepin, gabapentin, and pregabalin, individually or in combination. Nonetheless, some patients experience severe and intractable pain despite such medication, or the medication eliminates their pain but they experience intolerable side effects sufficient to warrant discontinuation. Intravenous magnesium and lidocaine have been used for management of intractable neuropathic pain. We treated nine patients with TN by using an intravenous infusion of a combination of 1.2 g magnesium and 100 mg lidocaine for 1 hour, once a week for 3 weeks. All patients experienced sound pain relief after the combined intravenous infusion therapy. Two patients experienced short and mild dizziness after the therapy, but no severe side effects were reported.

The effects of exercise therapy for the improvement of jaw movement and psychological intervention to reduce parafunctional activities on chronic pain in the craniocervical region

PURPOSE

Apparent organic abnormalities are sometimes not identified among patients suffering from chronic pain in the craniocervical region. In some cases, parafunctional activities (PAs) are recognized. PAs are nonfunctional oromandibular activities that include jaw clenching and bruxism, but are considered as factors that contribute to craniomandibular disorders (CMDs). It is now recognized that PAs and CMDs influence musculoskeletal conditions of the upper quarter. Exercise therapy (ET) to improve jaw movement and psychological intervention (PI) to reduce PAs are useful for PAs and CMDs. We hypothesized that ET and PI would be effective for craniocervical pain without organic abnormalities.

METHODS

Thirty-nine subjects suffering from craniocervical chronic pain were allocated into 3 groups: The control group received only pharmacological treatment; the ET group received jaw movement exercise (JME); and the ET-PI group received JME and PI. Pain and jaw movement were evaluated using a numerical rating scale (NRS).

RESULTS

After interventions, the NRS scores were significantly lower in the ET-PI group, compared with those in the other groups. Jaw movement improved 100% in the ET group, 92% in the ET-PI group, and 0% in the control group.

CONCLUSION

A combination of jaw exercise and psychological intervention to reduce parafunctional activities is more effective than jaw exercise alone for the improvement of craniocervical pain without apparent organic abnormalities.

Behavioral and neuropathological changes in animal models of chronic painful scar

BACKGROUND

Long-lasting limb pain or back pain after surgery occasionally develops into chronic pain that leads to lower activity and a poorer quality of life for many patients. To determine the histopathological and neuropathological mechanisms that cause persistent post-operative pain, we developed an original animal model with sustained painful scars and then examined pain-related behavior and the pathological alteration of peripheral tissues and spinal nerves associated with the model.

METHODS

The animal model (Scar group) was prepared in rats by extensively stripping subcutaneous tissue from the plantar in the hind paw followed by subsequent examination of pain-related behavior over the next 12 weeks. Thereafter, we conducted histological staining of the scar tissues, immunohistochemical staining of c-Fos (L5 dorsal horn), and electron microscopic analysis of the L5 spinal nerve fibers/dorsal roots.

RESULTS

The mechanical pain threshold decreased specifically in the ipsilateral plantar in animals with scar. This state was maintained for 12 weeks. A collagen layer developed from fibers derma to the muscular layer in the scar tissue in which many fibroblasts were observed. No statistical differences were found for the areas of the c-Fos-immunoreactive (c-Fos-IR) neurons in the ipsilateral and contralateral sides of the L5 level of the dorsal horn in both the Scar group and Pinhole (sham operation) group. However, myelin sheath fragmentation of the nerve fibers was observed in the ipsilateral dorsal root at the L5 position.

CONCLUSIONS

We created a persistent painful scar model through extensive injury of the peripheral tissues. Fibrotic thickening of the cutaneous tissues, possible sensitization, and partial degradation of the spinal nerve related to the painful scar were observed. This model should enable us to better understand the mechanism of sensitization caused by painful scar and investigate new methods for treating painful scars in humans.

Effect of muscle load tasks with maximal isometric contractions on oxygenation of the trapezius muscle and sympathetic nervous activity in females with chronic neck and shoulder pain

Background

Sympathetic nervous activity contributes to the maintenance of muscle oxygenation. However, patients with chronic pain may suffer from autonomic dysfunction. Furthermore, insufficient muscle oxygenation is observed among workers with chronic neck and shoulder pain. The aim of our study was to investigate how muscle load tasks affect sympathetic nervous activity and changes in oxygenation of the trapezius muscles in subjects with chronic neck and shoulder pain.

Methods

Thirty females were assigned to two groups: a pain group consisting of subjects with chronic neck and shoulder pain and a control group consisting of asymptomatic subjects. The participants performed three sets of isometric exercise in an upright position; they contracted their trapezius muscles with maximum effort and let the muscles relax (Relax). Autonomic nervous activity and oxygenation of the trapezius muscles were measured by heart rate variability (HRV) and Near-Infrared Spectroscopy.

Results

Oxyhemoglobin and total hemoglobin of the trapezius muscles in the pain group were lower during the Relax period compared with the control group. In addition, the low frequency / high frequency (LF/HF) ratio of HRV significantly increased during isometric exercise in the control group, whereas there were no significant changes in the pain group.

Conclusions

Subjects with neck and shoulder pain showed lower oxygenation and blood flow of the trapezius muscles responding to isometric exercise, compared with asymptomatic subjects. Subjects with neck and shoulder pain also showed no significant changes in the LF/HF ratio of HRV responding to isometric exercise, which would imply a reduction in sympathetic nervous activity.

The Influence of Acupressure at Extra 1 Acupuncture Point on the Spectral Entropy of the EEG and the LF/HF Ratio of Heart Rate Variability

Acupressure applied on the Extra 1 acupuncture point results in sedation, thereby reducing bispectral index (BIS) values. Mental status and hypnotic agents influence the autonomic nervous system. We hypothesized that acupressure at the Extra 1 point would induce sedation and change sympatho-parasympathetic nerve balance. We investigated the effect of acupressure at the Extra 1 point on the EEG spectral entropy values and heart rate variability (HRV). Forty-eight volunteers (24 males and 24 females) were randomly assigned to the control or Extra 1 group. The control group received acupressure at a sham point and the Extra 1 group received acupressure at the Extra 1 point. Acupressure was applied for 5 min. The record of the EEG spectral entropy values and HRV started 5 min before acupressure and stopped 5 min after acupressure. Acupressure significantly reduced the EEG spectral entropy values in both groups, but the values of the Extra 1 group were significantly smaller than those of the control group (P < .01). Acupressure significantly decreased the LF/HF ratio of HRV in both groups (P < .05). When divided upon gender, although acupressure tended to decrease the LF/HF ratio, the ratio significantly decreased during and after acupressure only in females of the Extra 1 group (P < .05). We concluded that acupressure on the Extra 1 point significantly reduced the EEG spectral entropy in both the genders, but affected the LF/HF ratio of HRV only in females.

Auricular Acupunctures are Effective for the Prevention of Postoperative Agitation in Old Patients

Postoperative cognitive problems and delirium are not uncommon in the elderly. We reported four cases in which auricular acupunctures on the ‘Shenmen’ and ‘Point Zero’ points successfully managed postoperative problematic behaviors of the three patients with dementia and the one patient postoperatively demonstrating an agitated behavior.

Intradermal administration of magnesium sulphate and magnesium chloride produces hypesthesia to mechanical but hyperalgesia to heat stimuli in humans

Background

Although magnesium ions (Mg²⁺) are known to display many similar features to other 2+ charged cations, they seem to have quite an important and unique role in biological settings, such as NMDA blocking effect. However, the role of Mg²⁺ in the neural transmission system has not been studied as sufficiently as calcium ions (Ca²⁺). To clarify the sensory effects of Mg²⁺ in peripheral nervous systems, sensory changes after intradermal injection of Mg²⁺ were studied in humans.

Methods

Magnesium sulphate, magnesium chloride and saline were injected into the skin of the anterior region of forearms in healthy volunteers and injection-induced irritating pain ("irritating pain", for short), tactile sensation, tactile pressure thresholds, pinch-pain changes and intolerable heat pain thresholds of the lesion were monitored.

Results

Flare formation was observed immediately after magnesium sulphate or magnesium chloride injection. We found that intradermal injections of magnesium sulphate and magnesium chloride transiently caused irritating pain, hypesthesia to noxious and innocuous mechanical stimulations, whereas secondary hyperalgesia due to mechanical stimuli was not observed. In contrast to mechanical stimuli, intolerable heat pain-evoking temperature was significantly decreased at the injection site. In addition to these results, spontaneous pain was immediately attenuated by local cooling.

Conclusion

Membrane-stabilizing effect and peripheral NMDA-blocking effect possibly produced magnesium-induced mechanical hypesthesia, and extracellular cation-induced sensitization of TRPV1 channels was thought to be the primary mechanism of magnesium-induced heat hyperalgesia.

Complex of branched cyclodextrin and lidocaine prolonged the duration of peripheral nerve block

Although laboratories have tried to synthesize new local anesthetics, currently available local anesthetics rarely provide prolonged regional blockade. New models of sustained-release preparations of local anesthetics with liposomes and microspheres have been studied to prolong the duration of the effects of the local anesthetics. In the present study, we examined whether a complex of a branched cyclodextrin (CD), 6-O-alpha-D-maltosyl-beta-cyclodextrin (G2-beta-CD) and lidocaine could prolong local nerve block when compared with plain lidocaine. The sciatic nerve in male Sprague-Dawley rats was blocked with plain lidocaine (n = 10), the complex of G2-beta-CD + lidocaine (n = 10), or plain G2-beta-CD (n = 4). Sensory block was assessed with a hotplate set at 56 degrees C. The median duration of the block was longer in the complex group than in the plain lidocaine group (110 min; range, 70-150 min vs 55 min; range, 40-80 min; P < 0.05), thus demonstrating that the complex with CyD significantly prolonged the nerve block effect of lidocaine. In conclusion, the present study showed that this encapsulating technique with CyD is useful to expand local anesthetic effect in peripheral nerve blockade.

The effect of acupressure at the extra 1 point on subjective and autonomic responses to needle insertion

BACKGROUND

Premedication with sedatives can decrease the discomfort associated with invasive anesthetic procedures. Some researchers have shown that acupressure on the acupuncture extra 1 point is effective for sedation. We investigated whether acupressure on the extra 1 point could alleviate the pain of needle insertion.

METHODS

We investigated the effect of acupressure at the extra 1 point or a sham point on needle insertion using verbal rating scale (VRS) pain scores and heart rate variability (HRV). Twenty-two healthy female volunteers were randomly allocated to two groups: the extra 1 group received acupressure at the extra 1 point, and the sham group received acupressure at a sham point. After starting the electrocardiogram record, a 27-gauge needle was inserted into the skin of a forearm. Thereafter, another needle was inserted into the skin of the other forearm during acupressure.

RESULTS

Acupressure at the extra 1 point significantly reduced the VRS, but acupressure at the sham increased the VRS. Acupressure at the extra 1 significantly reduced the low frequency/high frequency ratio of HRV responding to needle insertion.

CONCLUSIONS

Acupressure at the extra 1 point significantly reduced needle insertion pain compared with acupressure at the sham point. Also, acupressure at the extra 1 point significantly reduced the low frequency/high frequency ratio of HRV responding to needle insertion, which implies a reduction in sympathetic nervous system activity.

Maternal heart rate variability just before surgery significantly correlated with emergence behavior of children undergoing general anesthesia

BACKGROUND

Emergence agitation in pediatric anesthesia is associated with preanesthesia child anxiety, which is strongly influenced by maternal mental conditions. Mental stress affects the autonomic nervous system, thereby influencing heart rate variability (HRV). The present study tested the correlations between preanesthesia maternal HRV and perioperative child behavior.

METHODS

A total of 27 pairs of mothers and children were analyzed in the present study. Maternal HRV was recorded from the night before the child's surgery to arrival to the operation room and thereafter recorded data were analyzed. The children underwent minor plastic surgery under general anesthesia, and induction and emergence behavior were assessed.

RESULTS

Quality of mask induction did not correlate with the ratio of low-frequency (LF) components to high-frequency (HF) components (LF/HF ratio) of preanesthesia maternal HRV either obtained during 21:00-06:00 (stage I) or 06:00-08:00 (stage II). Scores of the child's emergence behavior did not correlate with the LF/HF ratio of maternal HRV of stage I; however, the LF/HF ratio of maternal HRV of stage II significantly correlated with emergence behavior.

CONCLUSIONS

Two-hour maternal HRV just before surgery significantly correlated with emergence behavior of children undergoing general anesthesia.

The effects of jaw thrust and the lateral position on heart rate variability in anesthetized children with obstructive sleep apnea syndrome

BACKGROUND

Airway obstruction occurs in anesthetized children with obstructive sleep apnea syndrome (OSAS). The inspiratory attempts against the occluded airway lead to an increased sympathetic activity. Heart rate variability (HRV) analysis provides information about the autonomic nervous system. The low-frequency component/high-frequency component ratio of HRV is considered to be an index of sympatho-parasympathetic balance.

METHODS

We investigated the effects of general anesthesia, the neutral neck position, and jaw thrust in the supine and lateral positions on HRV in 20 children (aged 3-9 yr), with OSAS. HRV was recorded before and after anesthesia induction, at the neutral neck position and with jaw thrust maneuver in the supine and lateral positions with the patients breathing 5% sevoflurane.

RESULTS

General anesthesia with the patient in the neutral neck position increased airway obstruction. The patients' stridor scores improved with the airway maneuver of jaw thrust and lateral position. The low-frequency component/high-frequency component ratio and heart rate increased at the postinduction measurement and reached the highest value with the patient in the neutral neck position. The values significantly decreased with the jaw thrust maneuver and with the patient in the supine and lateral positions. Ultra-short-term entropy of HRV decreased after anesthetic induction and reached the lowest value with the patient in the neutral neck position. The values increased during jaw thrust and with patients in the supine and lateral positions.

CONCLUSIONS

Changes of HRV induced by inhaled anesthesia, jaw thrust, and lateral positioning procedures corresponded to changes in the stridor score of children with OSAS.

The Influence of Hyperbaric Bupivacaine Temperature on the Spread of Spinal Anesthesia

The distribution of spinal anesthesia is affected by the density and viscosity of the local anesthetic solution that, in turn, may be influenced by the temperature of the injectate. Our hypothesis in the present study was that the temperature of the injectate influences its distribution into the subarachnoid space. We measured the density and viscosity of hyperbaric 0.5% bupivacaine at 25 degrees C and 37 degrees C and tested the onset and extent of spinal anesthesia achieved by these solutions in 36 patients. The densities of the two solutions were similar (mean [sd]): 25 degrees C, 1.028 [0.000], versus 37 degrees C, 1.028 [0.000] (g/mL), but the viscosity was more at 25 degrees C than at 37 degrees C (0.01116 [0.00003] versus 0.00843 [0.00002] g x cm(-1) x s(-1); P < 0.001). The maximum cephalad extent of loss of pinprick sensation was significantly higher with 37 degrees C (T2 with 37 degrees C versus T5 with 25 degrees C; P < 0.001), but the time to achieve peak block height was similar. In conclusion, we showed a consistent, but modest, increase in the cephalad level of spinal anesthesia by warming hyperbaric bupivacaine 0.5% from 25 degrees C to 37 degrees C. Viscosity was reduced in the warmed solution, but it is unclear if this or other factors led to the difference in spinal anesthetic level.

The Endoscopically Measured Effects of Airway Maneuvers and the Lateral Position on Airway Patency in Anesthetized Children with Adenotonsillar Hypertrophy

Obstruction of the upper airway is a major challenge for anesthesiologists administering general anesthesia in spontaneously breathing children with adenotonsillar hypertrophy. Lateral positioning is a simple treatment for obstructive sleep apnea. In this study, we examined the effects of body position shifting and common airway maneuvers such as chin lift and jaw thrust on airway patency (stridor score and upper airway dimensions by endoscopy) in anesthetized children scheduled for adenotonsillectomy. Eighteen children aged 1-11 yr were anesthetized with sevoflurane. During spontaneous breathing with 5% sevoflurane and 100% oxygen, upper airway dimensions and stridor score were recorded. After baseline recording, chin lift and jaw thrust were performed in both the supine and the lateral decubitus position. Chin lift, jaw thrust, and lateral position increased the airway dimensions and improved the stridor score. Moreover, lateral positioning enhanced the effects of these airway maneuvers on airway patency. We concluded that lateral positioning combined with airway maneuvers provided better airway patency for anesthetized children with adenotonsillar hypertrophy.

The Effects of Chin Lift and Jaw Thrust While in the Lateral Position on Stridor Score in Anesthetized Children with Adenotonsillar Hypertrophy

Obstruction of the upper airway is a major challenge for anesthesiologists administering general anesthesia in spontaneously breathing patients, especially in pediatric anesthesia with adenotonsillar hypertrophy. Lateral positioning is a simple treatment for obstructive sleep apnea and also decreases collapsibility of the pharynx in anesthetized adults with obstructive sleep apnea. In this study, we examined the effects of body position shifting and common airway maneuvers, such as chin lift and jaw thrust, on airway patency (stridor score) in anesthetized children scheduled for adenotonsillectomy. Thirty children aged 1-10 yr were anesthetized with sevoflurane. During spontaneous breathing of 5% sevoflurane, stridor score was recorded. After baseline recording, chin lift and jaw thrust were performed on patients in both the supine and the lateral decubitus positions. Chin lift and jaw thrust improved the stridor score. Furthermore, lateral positioning dramatically enhanced the effects of these airway maneuvers on airway patency. Jaw thrust combined with lateral positioning provided easy airway management for the anesthesiologists. We conclude that lateral positioning combined with airway maneuvers significantly improved airway patency compared with the airway maneuvers alone for patients in the supine position.

Isoflurane increases, but sevoflurane decreases blood concentrations of melatonin in women

The blood concentrations of melatonin are elevated by stress-induced sympathetic nerve excitation and are affected by some anesthetics. Isoflurane has an effect to increase sympathetic nerve activity when compared with sevoflurane. This study was performed to investigate the effects of these two anesthetics on the blood concentrations of melatonin. Female patients were anesthetized with either isoflurane or sevoflurane. We obtained blood samples before and 5 min after 5% isoflurane (ISO group) or 7% sevoflurane (SEV group) anesthesia. The blood melatonin concentrations during anesthesia in the ISO group increased significantly, from 65 +/- 60 to 170 +/- 90 pg x ml(-l); mean +/- SD ( P < 0.05), whereas those in the SEV group decreased, from 60 +/- 50 to 30 +/- 30 pg x ml(-l) ( P < 0.05). In conclusion, isoflurane increases, but sevoflurane decreases blood melatonin concentrations.

Warm Steaming Enhances the Topical Anesthetic Effect of Lidocaine

Warm steaming has been used for hydrating the skin, thereby increasing its permeability. We studied whether skin pretreatment with a steamed towel (at 45 degrees C) for 5 min could enhance the anesthetic effect of a topical lidocaine tape in 14 female volunteers. After each volunteer received the skin pretreatment on one of the forearms, lidocaine tape was applied for 30 min on both the treated and the untreated forearms. Superficial anesthesia was scored by recording the number of painful experience during 5 pinpricks delivered with a 27-gauge needle. To assess anesthesia of the deeper layer, single insertion of a 27-gauge needle to a depth of 3 mm was made and pain was scored by a visual analog scale (VAS). There were significant reductions in the scores of superficial anesthesia (median [range]: treated arm, 2 [0-5], versus untreated arm, 4 [1-5]; P < 0.01) and the VAS scores of deeper insertion (median [range]: treated arm, 4.5 [0-8], versus untreated arm, 8 [2-10]; P < 0.01). In conclusion, the application of a warm steamed towel enhanced the anesthetic effect of a topical lidocaine tape.

IMPLICATIONS

We showed that the skin pretreatment with a steamed towel (at 45 degrees C) enhanced the anesthetic effect of a topical lidocaine tape in female volunteers.