Correlation Between Gut Microbiome Composition and Acute Pain Perception in Young Healthy Male Subjects.

OBJECTIVE: Recently, there has been growing interest in the gut-brain axis because it is emerging as a player influencing the health status of the host human. It is a known fact that the gut microbiome (GM) through the gut-brain axis has been implicated in numerous diseases. We previously reported that stool condition was associated with pain perception. Stool consistency and constipation are known to be associated with GM composition. Thus, we imagine that GM composition could influence pain perception. The aim of this study was to investigate the correlations between GM composition and pain perception and psychological states in young healthy male subjects. SUBJECTS: A total of 42 healthy young male volunteers completed the present study. METHODS: The volunteers' pain perceptions were assessed by pressure pain threshold, current perception threshold, temporal summation of pain, and conditioned pain modulation, and a questionnaire on psychological state was obtained. During the current perception threshold examination, we used 5, 250, and 2,000 Hz to stimulate C, Aδ, and Aß fibers. In addition, GM composition was evaluated by using 16S rRNA analysis. RESULTS: Pressure pain threshold showed a significant and negative correlation with Bacteroidetes phylum, in contrast to a significant and positive correlation with Firmicutes phylum. Current perception threshold of Aδ and Firmicutes phylum showed a significant correlation. There was a negative correlation between anxiety state and Bifidobacterium genus. In contrast, there was no significant correlation between psychological states and pain perceptions. CONCLUSION: The present study showed that acute pain perception was associated with GM composition in young healthy males.

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.

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.

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.

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 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.

Virtual pain stimulation of allodynia patients activates cortical representation of pain and emotions: a functional MRI study.

The present study investigated neural correlates of affect processing in allodynia patients (n=8) and healthy controls (n=12) with the aid of virtual tactile stimulation. Whole brain functional magnetic resonance imaging was performed for allodynia patients and healthy volunteers while they were shown a video demonstrating light stimulation of the palm and another stimulation aimed at producing anticipation of palm stimulation. Contrasting with controls, patients displayed activation of the cortical areas related to pain and emotions: prefrontal cortex (Brodmann's area BA 10) and anterior cingulate cortex (BA 24). These findings may indicate involvement of an emotional component of pain perception in all odynia patients.

A comparative study of sequential epidural bolus technique and continuous epidural infusion.

BACKGROUND: In this randomized, double-blind study, the authors compared the effectiveness of a sequential epidural bolus (SEB) technique versus a standard continuous epidural infusion (CEI) technique of local anesthetic delivery. Both techniques used the same hourly dose of local anesthetic. METHODS: Sixteen gynecologic patients undergoing abdominal surgery received postoperative epidural analgesia using 0.75% ropivacaine at a dose of 22.5 mg (3 ml) per hour. Patients were randomly assigned to one of two groups. In the SEB group (n = 8), patients received one third of the hourly dose every 20 min as a bolus. In the CEI group (n = 8), the hourly dose was administered as a continuous infusion. Analgesia was assessed by rest pain scored by a visual analog scale and pinprick to determine the number of separately blocked spinal segments on each side of the body. Doses of rescue medication for pain were also recorded. RESULTS: The median number of blocked spinal segments was 19.5 (range, 18-24) in the SEB group and 11.5 (range, 10-18) in the CEI group (P < 0.001). The median difference in the number of blocked segments between the right and left sides was 0 (range, 0-1) in the SEB group and 2 (range, 0-6) in the CEI group (P < 0.04). No patients in the SEB group but one patient in the CEI group required rescue medication for pain. The visual analog scale pain score was 0 in both groups except for one patient in the CEI group during the study period. CONCLUSION: The SEB technique with ropivacaine provides superior epidural block compared with an identical hourly dose administered as a continuous infusion.

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.

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.

UNLABELLED: 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.