1
|
Effects of Etco2 on the Minimum Alveolar Concentration of Sevoflurane that Blunts the Adrenergic Response to Surgical Incision: A Prospective, Randomized, Double-Blinded Trial. Anesth Analg 2021; 135:62-70. [PMID: 34744156 DOI: 10.1213/ane.0000000000005784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND CO2 has anesthetic potency and effectively influences the circulatory system. We investigated the effects of Etco2 on the minimum alveolar concentration of sevoflurane that blunts the adrenergic response to surgical incision (MAC-BAR) in patients undergoing radical surgery for gastric carcinoma. METHODS Ninety patients undergoing radical gastric-carcinoma surgery under general anesthesia were enrolled and randomly assigned into 3 groups. After intubation, the Etco2 in group L (n = 30), group N (n = 30), and group H (n = 30) was adjusted to 25 mm Hg ≤ Etco2 <30 mm Hg, 30 mm Hg ≤ Etco2 < 40 mm Hg, and 40 mm Hg ≤ Etco2 < 45 mm Hg, respectively, by changes in controlled ventilation. Hemodynamics and depth of anesthesia were observed before and after skin incision. The MAC-BAR of sevoflurane for each group was determined using an up-and-down sequential-allocation technique. RESULTS To obtain 7 crossovers, 25, 26, and 26 patients were used in group L, group N, and group H, respectively. The MAC-BAR of sevoflurane using the up-and-down method for group H was significantly lower than that for group L (2.3% [95% confidence interval {CI}, 2.2-2.4] vs 2.9% [95% CI, 2.7-3.0]; difference, -0.6% [95% CI, -0.7 to -0.4], P < .001) and group N (2.3% [95% CI, 2.2-2.4] vs 2.8% [95% CI, 2.8-2.9]; difference, -0.5% [95% CI, -0.7 to -0.4], P < .001), while no significant difference was found between group L and group N (P = 1.000). CONCLUSIONS Higher Etco2 levels (Etco2 values equal to 40 mm Hg or higher) can effectively decrease the MAC-BAR of sevoflurane in patients undergoing radical surgery for gastric carcinoma.
Collapse
|
2
|
Kraft E, Storz C, Ranker A. [Physical therapy in the treatment of complex regional pain syndrome]. Schmerz 2021; 35:363-372. [PMID: 34529155 DOI: 10.1007/s00482-021-00577-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Accepted: 06/09/2021] [Indexed: 11/26/2022]
Abstract
The treatment of patients with complex regional pain syndrome (CRPS) takes place in an interdisciplinary and multimodal setting. Physical therapies represent a major treatment focus along with physiotherapy, occupational therapy, and analgetic treatments. This review explains their importance in current clinical practice and gives an impression of the evidence on different treatments including electrotherapy, neuromodulating procedures, manual lymphatic drainage, CO2 applications and paraffin wax baths. As far as ascertainable from clinical experience and the scientific literature, treatment recommendations are presented in accordance with current guidelines.
Collapse
Affiliation(s)
- Eduard Kraft
- Muskuloskelettales Universitätszentrum München, LMU Klinikum, München, Deutschland.
- Interdisziplinäre Schmerzambulanz, Campus Großhadern, LMU Klinikum, München, Deutschland.
| | - Claudia Storz
- Muskuloskelettales Universitätszentrum München, LMU Klinikum, München, Deutschland
| | - Alexander Ranker
- Muskuloskelettales Universitätszentrum München, LMU Klinikum, München, Deutschland
- Klinik für Rehabilitationsmedizin, MHH Hannover, Hannover, Deutschland
| |
Collapse
|
3
|
Dangers L, Laviolette L, Georges M, Gonzalez-Bermejo J, Rivals I, Similowski T, Morelot-Panzini C. Relieving dyspnoea by non-invasive ventilation decreases pain thresholds in amyotrophic lateral sclerosis. Thorax 2016; 72:230-235. [PMID: 27507899 DOI: 10.1136/thoraxjnl-2016-208544] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 07/11/2016] [Accepted: 07/16/2016] [Indexed: 01/12/2023]
Abstract
BACKGROUND Dyspnoea is a threatening sensation of respiratory discomfort that presents many similarities with pain. Experimental dyspnoea in healthy subjects induces analgesia. This 'dyspnoea-pain counter-irritation' could, in reverse, imply that relieving dyspnoea in patients with chronic respiratory diseases would lower their pain thresholds. METHODS We first determined pressure pain thresholds in 25 healthy volunteers (22-31 years; 13 men; handheld algometer), during unloaded breathing (BASELINE) and during inspiratory threshold loading (ITL). Two levels of loading were used, adjusted to induce dyspnoea self-rated at 60% or 80% of a 10 cm visual analogue scale (ITL6 and ITL8). 18 patients with chronic respiratory failure due to amyotrophic lateral sclerosis (ALS) were then studied during unassisted breathing and after 30 and 60 min of non-invasive ventilation-NIV30 and NIV60-(same dyspnoea evaluation). RESULTS In healthy volunteers, pressure pain thresholds increased significantly in the deltoid during ITL6 (p<0.05) and ITL8 (p<0.05) and in the trapezius during ITL8 (p<0.05), validating the use of pressure pain thresholds to study dyspnoea-pain counter-irritation. In patients with ALS, the pressure pain thresholds measured in the deltoid during unassisted breathing decreased by a median of 24.5%-33.0% of baseline during NIV30 and NIV60 (p<0.05). CONCLUSION Relieving dyspnoea by NIV in patients with ALS having respiratory failure is associated with decreased pressure pain thresholds. Clinical implications have yet to be determined, but this observation suggests that patients with ALS could become more susceptible to pain after the institution of NIV, hence the need for reinforced attention towards potentially painful diagnostic and therapeutic interventions.
Collapse
Affiliation(s)
- Laurence Dangers
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, UMRS1158 Neurophysiologie respiratoire expérimentale et clinique, Paris, France.,Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service de Pneumologie et Réanimation Médicale (Département 'R3S'), AP-HP, Paris, France
| | - Louis Laviolette
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, UMRS1158 Neurophysiologie respiratoire expérimentale et clinique, Paris, France.,Centre de recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec (CRIUCPQ), Québec, Canada
| | - Marjolaine Georges
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, UMRS1158 Neurophysiologie respiratoire expérimentale et clinique, Paris, France.,Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service de Pneumologie et Réanimation Médicale (Département 'R3S'), AP-HP, Paris, France
| | - Jésus Gonzalez-Bermejo
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, UMRS1158 Neurophysiologie respiratoire expérimentale et clinique, Paris, France.,Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service de Pneumologie et Réanimation Médicale (Département 'R3S'), AP-HP, Paris, France
| | - Isabelle Rivals
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, UMRS1158 Neurophysiologie respiratoire expérimentale et clinique, Paris, France.,Ecole Supérieure de Physique et de Chimie de la Ville de Paris, Paris, France
| | - Thomas Similowski
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, UMRS1158 Neurophysiologie respiratoire expérimentale et clinique, Paris, France.,Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service de Pneumologie et Réanimation Médicale (Département 'R3S'), AP-HP, Paris, France
| | - Capucine Morelot-Panzini
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, UMRS1158 Neurophysiologie respiratoire expérimentale et clinique, Paris, France.,Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service de Pneumologie et Réanimation Médicale (Département 'R3S'), AP-HP, Paris, France
| |
Collapse
|
4
|
Dangers L, Laviolette L, Charbit B, Similowski T, Morélot-Panzini C. Nefopam, a non-opioid analgesic, does not alleviate experimental work/effort dyspnoea in healthy humans: A randomised controlled trial. Pulm Pharmacol Ther 2016; 39:74-80. [DOI: 10.1016/j.pupt.2016.06.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 06/19/2016] [Accepted: 06/23/2016] [Indexed: 01/10/2023]
|
5
|
Dangers L, Laviolette L, Similowski T, Morélot-Panzini C. Interactions Between Dyspnea and the Brain Processing of Nociceptive Stimuli: Experimental Air Hunger Attenuates Laser-Evoked Brain Potentials in Humans. Front Physiol 2015; 6:358. [PMID: 26648875 PMCID: PMC4664703 DOI: 10.3389/fphys.2015.00358] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 11/13/2015] [Indexed: 12/31/2022] Open
Abstract
Dyspnea and pain share several characteristics and certain neural networks and interact with each other. Dyspnea-pain counter-irritation consists of attenuation of preexisting pain by intercurrent dyspnea and has been shown to have neurophysiological correlates in the form of inhibition of the nociceptive spinal reflex RIII and laser-evoked potentials (LEPs). Experimentally induced exertional dyspnea inhibits RIII and LEPs, while “air hunger” dyspnea does not inhibit RIII despite its documented analgesic effects. We hypothesized that air hunger may act centrally and inhibit LEPs. LEPs were obtained in 12 healthy volunteers (age: 21–29) during spontaneous breathing (FB), ventilator-controlled breathing (VC) tailored to FB, after inducing air hunger by increasing the inspired fraction of carbon dioxide -FiCO2- (VCCO2), and during ventilator-controlled breathing recovery (VCR). VCCO2 induced intense dyspnea (visual analog scale = 63% ± 6% of full scale, p < 0.001 vs. VC), predominantly of the air hunger type. VC alone reduced the amplitude of the N2-P2 component of LEPs (Δ = 24.0% ± 21.1%, p < 0.05, effect-size = 0.74) predominantly through a reduction in P2, and the amplitude of this inhibition was further reduced by inducting air hunger (Δ = 22.6% ± 17.9%, p < 0.05, effect-size = 0.53), predominantly through a reduction in N2. Somatosensory-evoked potentials (SEPs) were not affected by VC or VCCO2, suggesting that the observed effects are specific to pain transmission. We conclude that air hunger interferes with the cortical mechanisms responsible for the cortical response to painful laser skin stimulation, which provides a neurophysiological substrate to the central nature of its otherwise documented analgesic effects.
Collapse
Affiliation(s)
- Laurence Dangers
- Sorbonne Universités, University Pierre et Marie Curie Univ Paris 06, UMR_S 1158 "Neurophysiologie Respiratoire Expérimentale et Clinique" Paris, France ; Institut National de la Santé et de la Recherche Médicale, UMR_S 1158 "Neurophysiologie Respiratoire Expérimentale et Clinique" Paris, France ; Assistance Publique des Hôpitaux de Paris, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service de Pneumologie et Réanimation Médicale (Département "R3S") Paris, France
| | - Louis Laviolette
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec Québec, QC, Canada
| | - Thomas Similowski
- Sorbonne Universités, University Pierre et Marie Curie Univ Paris 06, UMR_S 1158 "Neurophysiologie Respiratoire Expérimentale et Clinique" Paris, France ; Institut National de la Santé et de la Recherche Médicale, UMR_S 1158 "Neurophysiologie Respiratoire Expérimentale et Clinique" Paris, France ; Assistance Publique des Hôpitaux de Paris, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service de Pneumologie et Réanimation Médicale (Département "R3S") Paris, France
| | - Capucine Morélot-Panzini
- Sorbonne Universités, University Pierre et Marie Curie Univ Paris 06, UMR_S 1158 "Neurophysiologie Respiratoire Expérimentale et Clinique" Paris, France ; Institut National de la Santé et de la Recherche Médicale, UMR_S 1158 "Neurophysiologie Respiratoire Expérimentale et Clinique" Paris, France ; Assistance Publique des Hôpitaux de Paris, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service de Pneumologie et Réanimation Médicale (Département "R3S") Paris, France
| |
Collapse
|
6
|
Wang D, Yee BJ, Wong KK, Kim JW, Dijk DJ, Duffin J, Grunstein RR. Comparing the effect of hypercapnia and hypoxia on the electroencephalogram during wakefulness. Clin Neurophysiol 2015; 126:103-9. [DOI: 10.1016/j.clinph.2014.04.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 04/07/2014] [Accepted: 04/12/2014] [Indexed: 01/01/2023]
|
7
|
Wang D, Piper AJ, Yee BJ, Wong KK, Kim JW, D'Rozario A, Rowsell L, Dijk DJ, Grunstein RR. Hypercapnia is a key correlate of EEG activation and daytime sleepiness in hypercapnic sleep disordered breathing patients. J Clin Sleep Med 2014; 10:517-22. [PMID: 24910553 PMCID: PMC4046358 DOI: 10.5664/jcsm.3700] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND The key determinants of daytime drowsiness in sleep disordered breathing (SDB) are unclear. Hypercapnia has not been examined as a potential contributor due to the lack of reliable measurement during sleep. To overcome this limitation, we studied predominantly hypercapnic SDB patients to investigate the role of hypercapnia on EEG activation and daytime sleepiness. METHODS We measured overnight polysomnography (PSG), arterial blood gases, and Epworth Sleepiness Scale in 55 severe SDB patients with obesity hypoventilation syndrome or overlap syndrome (COPD+ obstructive sleep apnea) before and ∼3 months after positive airway pressure (PAP) treatment. Quantitative EEG analyses were performed, and the Delta/ Alpha ratio was used as an indicator of EEG activation. RESULTS After the PAP treatment, these patients showed a significant decrease in their waking pCO(2), daytime sleepiness, as well as all key breathing/oxygenation parameters during sleep. Overnight Delta/Alpha ratio of EEG was significantly reduced. There is a significant cross-correlation between a reduced wake pCO(2), a faster (more activated) sleep EEG (reduced Delta/Alpha ratio) and reduced daytime sleepiness (all p < 0.05) with PAP treatment. Multiple regression analyses showed the degree of change in hypercapnia to be the only significant predictor for both ESS and Delta/ Alpha ratio. CONCLUSIONS Hypercapnia is a key correlate of EEG activation and daytime sleepiness in hypercapnic SDB patients. The relationship between hypercapnia and sleepiness may be mediated by reduced neuro-electrical brain activity.
Collapse
Affiliation(s)
- David Wang
- Department of Respiratory and Sleep Medicine, Royal Prince Alfred Hospital, Sydney, Australia (work performed)
- Woolcock Institute of Medical Research, University of Sydney, Sydney, Australia
| | - Amanda J. Piper
- Department of Respiratory and Sleep Medicine, Royal Prince Alfred Hospital, Sydney, Australia (work performed)
- Woolcock Institute of Medical Research, University of Sydney, Sydney, Australia
| | - Brendon J. Yee
- Department of Respiratory and Sleep Medicine, Royal Prince Alfred Hospital, Sydney, Australia (work performed)
- Woolcock Institute of Medical Research, University of Sydney, Sydney, Australia
- Centre for Integrated Research and Understanding of Sleep (CIRUS), University of Sydney, Sydney, Australia
| | - Keith K. Wong
- Department of Respiratory and Sleep Medicine, Royal Prince Alfred Hospital, Sydney, Australia (work performed)
- Woolcock Institute of Medical Research, University of Sydney, Sydney, Australia
- Centre for Integrated Research and Understanding of Sleep (CIRUS), University of Sydney, Sydney, Australia
| | - Jong-Won Kim
- Centre for Integrated Research and Understanding of Sleep (CIRUS), University of Sydney, Sydney, Australia
- School of Physics, University of Sydney, Sydney, Australia
| | - Angela D'Rozario
- Woolcock Institute of Medical Research, University of Sydney, Sydney, Australia
- Centre for Integrated Research and Understanding of Sleep (CIRUS), University of Sydney, Sydney, Australia
| | - Luke Rowsell
- Woolcock Institute of Medical Research, University of Sydney, Sydney, Australia
| | - Derk-Jan Dijk
- Surrey Sleep Research Centre, University of Surrey, UK
| | - Ronald R. Grunstein
- Department of Respiratory and Sleep Medicine, Royal Prince Alfred Hospital, Sydney, Australia (work performed)
- Woolcock Institute of Medical Research, University of Sydney, Sydney, Australia
- Centre for Integrated Research and Understanding of Sleep (CIRUS), University of Sydney, Sydney, Australia
| |
Collapse
|
8
|
Analgesic effects of dyspnoea: “Air hunger” does not inhibit the spinal nociception reflex in humans. Respir Physiol Neurobiol 2014; 190:81-5. [DOI: 10.1016/j.resp.2013.09.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 09/21/2013] [Accepted: 09/28/2013] [Indexed: 11/22/2022]
|
9
|
Tenenhaus M, Rennekampff HO. Surgical advances in burn and reconstructive plastic surgery: new and emerging technologies. Clin Plast Surg 2013; 39:435-43. [PMID: 23036294 DOI: 10.1016/j.cps.2012.07.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
This article introduces and discusses several biophysical and cellular modalities that are being tested or used in clinical practice to optimize wound bed preparation, effect soft tissue coverage, and improve the quality of the inevitable and resultant scar. Among these promising technologies is the use of electrical stimulation to mimic a physiologic current of injury in an effort to accelerate re-epithelialization and the wound healing process. Over the past several years an on-site individualized regenerative medicine kit has become commercially available (ReCell, Avita Medical), utilizing well-established laboratory techniques of cell separation without the need for cell cultivation in an effort to expand and promote wound coverage and end result.
Collapse
Affiliation(s)
- Mayer Tenenhaus
- Division of Plastic and Reconstructive Surgery, University of California San Diego Medical Center, 200 West, Arbor Drive, #8890, San Diego, CA 92103, USA.
| | | |
Collapse
|
10
|
Bouvier G, Laviolette L, Kindler F, Naccache L, Mouraux A, Similowski T, Morélot-Panzini C. Dyspnea-pain counterirritation induced by inspiratory threshold loading: a laser-evoked potentials study. J Appl Physiol (1985) 2012; 112:1166-73. [DOI: 10.1152/japplphysiol.01055.2011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Background: experimentally induced dyspnea of the work/effort type inhibits, in a top-down manner, the spinal transmission of nociceptive inputs (dyspnea-pain counterirritation). Previous studies have demonstrated that this inhibition can be assessed by measuring the nociceptive flexion reflex (RIII). However, its clinical application is limited because of the strong discomfort associated with the electrical stimuli required to elicit the RIII reflex. Study objectives: we examined whether the dyspnea-pain counterirritation phenomenon can be evaluated by measuring the effect of work/effort type dyspnea on the magnitude of laser-evoked brain potentials (LEPs). Methods: 10 normal male volunteers were studied (age: 19–30 years). LEPs were elicited using a CO2 laser stimulator delivering 10- to 15-ms stimuli of 6 ± 0.7 W over a 12.5 mm2 area. The EEG was recorded using nine scalp channels. Non-nociceptive somatosensory-evoked potentials (SEPs) served as control. LEPs and SEPs were recorded before, during, and after 10 min of experimentally induced dyspnea [inspiratory threshold loading (ITL)]. Results: pain caused by the nociceptive laser stimulus was mild. ITL consistently induced dyspnea, mostly of the “excessive effort” type. Amplitude of the N2-P2 wave of LEPs decreased by 37.6 ± 13.8% during ITL and was significantly correlated with the intensity of dyspnea [ r = 0.66, CI 95% (0.08–0.92, P = 0.0319)]. In contrast, ITL had no effect on the magnitude of non-nociceptive SEPs. Discussion: experimentally induced dyspnea of the work/effort type reduces the magnitude of LEPs. This reduction correlates with the intensity of dyspnea. The recording of LEPs could constitute a clinically applicable approach to assess the dyspnea-pain counterirritation phenomenon in patients.
Collapse
Affiliation(s)
- Guillaume Bouvier
- Université Paris 6, Laboratoire de Physiopathologie Respiratoire, Paris
| | - Louis Laviolette
- Université Paris 6, Laboratoire de Physiopathologie Respiratoire, Paris
| | - Felix Kindler
- Université Paris 6, Laboratoire de Physiopathologie Respiratoire, Paris
| | - Lionel Naccache
- Assistance Publique-Hôpitaux de Paris, Groupe Hospitalier Pitié-Salpêtrière, Départements de Neurologie et de Neurophysiologie, Paris, France
| | - André Mouraux
- Université Catholique de Louvain, Institut de Neuroscience, Louvain, Belgium; and
| | - Thomas Similowski
- Université Paris 6, Laboratoire de Physiopathologie Respiratoire, Paris
- Assistance Publique-Hôpitaux de Paris, Groupe Hospitalier Pitié-Salpêtrière, Service de Pneumologie et Réanimation Médicale, Paris, France
| | - Capucine Morélot-Panzini
- Université Paris 6, Laboratoire de Physiopathologie Respiratoire, Paris
- Assistance Publique-Hôpitaux de Paris, Groupe Hospitalier Pitié-Salpêtrière, Service de Pneumologie et Réanimation Médicale, Paris, France
| |
Collapse
|
11
|
Yashiro E, Nozaki-Taguchi N, Isono S, Nishino T. Effects of different forms of dyspnoea on pain perception induced by cold-pressor test. Respir Physiol Neurobiol 2011; 177:320-6. [DOI: 10.1016/j.resp.2011.05.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Revised: 05/11/2011] [Accepted: 05/12/2011] [Indexed: 10/18/2022]
|
12
|
Morélot-Panzini C, Demoule A, Straus C, Zelter M, Derenne JP, Willer JC, Similowski T. Dyspnea as a Noxious Sensation: Inspiratory Threshold Loading May Trigger Diffuse Noxious Inhibitory Controls in Humans. J Neurophysiol 2007; 97:1396-404. [PMID: 16870842 DOI: 10.1152/jn.00116.2006] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Dyspnea, a leading respiratory symptom, shares many clinical, physiological, and psychological features with pain. Both activate similar brain areas. The neural mechanisms of dyspnea are less well described than those of pain. The present research tested the hypothesis of common pathways between the two sensations. Six healthy men (age 30–40 yr) were studied. The spinal nociceptive flexion reflex (RIII) was first established in response to electrical sural stimulation. Dyspnea was then induced through inspiratory threshold loading, forcing the subjects to develop 70% of their maximal inspiratory pressure to inhale. This led to progressive inhibition of the RIII reflex that reached 50 ± 12% during the fifth minute of loading ( P < 0.001), was correlated to the intensity of the self-evaluated respiratory discomfort, and had recovered 5 min after removal of the load. The myotatic H-reflex was not inhibited by inspiratory loading, arguing against postsynaptic alpha motoneuron inhibition. Dyspnea, like pain, thus induced counterirritation, possibly indicating a C-fiber stimulation and activation of diffuse noxious inhibitory descending controls known to project onto spinal dorsal horn wide dynamic range neurons. This confirms the noxious nature of certain types of breathlessness, thus opening new physiological and perhaps therapeutic perspectives.
Collapse
Affiliation(s)
- Capucine Morélot-Panzini
- Laboratoire de Physiopathologie Respiratoire, Service de Pneumologie et de Réanimation, Groupe Hospitalier Pitié Salpétrière, 47-83 boulevard de l'Hôpital, 75651 Paris Cedex 13, France
| | | | | | | | | | | | | |
Collapse
|
13
|
Fukuda T, Hisano S, Toyooka H. Moderate hypercapnia-induced anesthetic effects and endogenous opioids. Neurosci Lett 2006; 403:20-3. [PMID: 16701947 DOI: 10.1016/j.neulet.2006.04.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2005] [Revised: 04/07/2006] [Accepted: 04/17/2006] [Indexed: 11/25/2022]
Abstract
The purpose of this report is to explore the mechanisms of hypercapnia-induced antinociception. We carried out three experiments, the first to confirm whether moderate hypercapnia induces anesthetic effects, the second to determine whether naloxone reverses the anesthetic effects, and the third to evaluate whether beta-endorphin is related to the anesthetic effects. In a pre-test, we determined the optimal CO(2) concentration in a chamber which would cause moderate hypercapnia in rats. Eighteen rats were divided into control, hypercapnia, and hypercapnia plus naloxone groups in experiment 1. The naloxone group rats were injected with naloxone (10 mg/kg) intraperitoneally before gas inhalation. After 60 min gas inhalation, 10% formalin was injected into the left rear paw of all rats, and nociceptive behaviors were observed for 1 h. In experiment 2, 11 rats were divided into control and hypercapnia groups. The brain was removed and fixed under pentobarbital anesthesia. Sections were immunostained for c-Fos and beta-endorphin (ACTH) with the ABC method. All neurons double-labeled for c-Fos and beta-endorphin (ACTH) in the arcuate nucleus were counted by blinded investigators. Moderate hypercapnia (PaCO(2) 83+/-7 mmHg) reduced nociceptive behavior in the formalin test and naloxone pre-treatment attenuated this phenomenon. However, beta-endorphin-producing neurons were not activated by CO(2) inhalation. Endogenous opioids are related to moderate, hypercapnia-induced anesthetic effects, but, beta-endorphin-producing neurons in the hypothalamus were not activated by the CO(2) inhalation stress.
Collapse
Affiliation(s)
- Taeko Fukuda
- Department of Anesthesiology, Institute of Clinical Medicine, Graduate School of Comprehensive Human Sciences, Tsukuba University, Tsukuba, Ibaraki 305-8575, Japan.
| | | | | |
Collapse
|
14
|
Brühwiler PA, Stämpfli R, Huber R, Camenzind M. CO2 and O2 concentrations in integral motorcycle helmets. APPLIED ERGONOMICS 2005; 36:625-33. [PMID: 15893291 DOI: 10.1016/j.apergo.2005.01.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2004] [Revised: 10/11/2004] [Accepted: 01/10/2005] [Indexed: 05/02/2023]
Abstract
Inhaling air which contains excess CO2 and/or is oxygen-deficient is known to present health risks and to diminish human cognitive abilities. The average CO2 concentrations relevant to a motorcyclist wearing an integral helmet were measured 20 years ago and found to be alarmingly large. The purpose of the present study was to examine gas concentrations typically inhaled by a motorcyclist. Average concentrations of CO2 near the upper lip for persons (n = 4) wearing integral motorcycle helmets were measured in the laboratory and the field to facilitate comparison to previous work, and similarly high average concentrations were found: above 2% when stationary, well below 1% for speeds of 50 km/h or more. Very good agreement was obtained between laboratory and field measurements. Detailed measurements of the time-dependent CO2 concentrations passing through a mouthpiece for mouth-breathing showed inhaled levels slightly over half of the corresponding average concentrations, including 1.3+/-0.3% at standstill, though higher concentrations (4% or more) were inhaled at the beginning of each breath. Opening the visor at standstill had on average no effect. At a speed of 50 km/h the inhaled CO2 concentration resembles that for a person without a helmet in still air, at about 0.2%. The oxygen deficiency is generally equal to the CO2 concentration, and could also contribute negatively to a motorcyclist's cognitive abilities.
Collapse
Affiliation(s)
- P A Brühwiler
- Empa, Materials Science and Technology, Lerchenfeldstrasse 5, CH-9014 St. Gallen, Switzerland.
| | | | | | | |
Collapse
|
15
|
Putnam RW, Filosa JA, Ritucci NA. Cellular mechanisms involved in CO(2) and acid signaling in chemosensitive neurons. Am J Physiol Cell Physiol 2004; 287:C1493-526. [PMID: 15525685 DOI: 10.1152/ajpcell.00282.2004] [Citation(s) in RCA: 221] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
An increase in CO(2)/H(+) is a major stimulus for increased ventilation and is sensed by specialized brain stem neurons called central chemosensitive neurons. These neurons appear to be spread among numerous brain stem regions, and neurons from different regions have different levels of chemosensitivity. Early studies implicated changes of pH as playing a role in chemosensitive signaling, most likely by inhibiting a K(+) channel, depolarizing chemosensitive neurons, and thereby increasing their firing rate. Considerable progress has been made over the past decade in understanding the cellular mechanisms of chemosensitive signaling using reduced preparations. Recent evidence has pointed to an important role of changes of intracellular pH in the response of central chemosensitive neurons to increased CO(2)/H(+) levels. The signaling mechanisms for chemosensitivity may also involve changes of extracellular pH, intracellular Ca(2+), gap junctions, oxidative stress, glial cells, bicarbonate, CO(2), and neurotransmitters. The normal target for these signals is generally believed to be a K(+) channel, although it is likely that many K(+) channels as well as Ca(2+) channels are involved as targets of chemosensitive signals. The results of studies of cellular signaling in central chemosensitive neurons are compared with results in other CO(2)- and/or H(+)-sensitive cells, including peripheral chemoreceptors (carotid body glomus cells), invertebrate central chemoreceptors, avian intrapulmonary chemoreceptors, acid-sensitive taste receptor cells on the tongue, and pain-sensitive nociceptors. A multiple factors model is proposed for central chemosensitive neurons in which multiple signals that affect multiple ion channel targets result in the final neuronal response to changes in CO(2)/H(+).
Collapse
Affiliation(s)
- Robert W Putnam
- Department of Anatomy and Physiology, Wright State University School of Medicine, 3640 Colonel Glenn Highway, Dayton, OH 45435, USA.
| | | | | |
Collapse
|
16
|
Wellner-Kienitz MC, Shams H, Scheid P. Contribution of Ca2+-activated K+ channels to central chemosensitivity in cultivated neurons of fetal rat medulla. J Neurophysiol 1998; 79:2885-94. [PMID: 9636094 DOI: 10.1152/jn.1998.79.6.2885] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Neurons in fetal rat medullary slices that exhibited spontaneous electrical activity after blockade of synaptic transmission were investigated for their response to decreases in extracellular pH. Increases in [H+] (induced either by fixed acid or increases in PCO2) induced a significant increase in the frequency of action potentials, associated with a membrane depolarization, and/or increases in the slope of the interspike depolarization. In addition, CO2/H+ prolonged the repolarizing phase of action potentials and reduced the afterhyperpolarization, suggesting that K+ channels were the primary site of CO2/H+ action. The type of K+ channel that was modulated by CO2/H+ was identified by application of agents that inhibited Ca2+-activated K+ channels either directly (tetraethylammonium chloride, TEA) or indirectly (Cd2+ ions) by inhibiting Ca2+ influx. CO2/H+ effects on neuronal activity were abolished after application of these blockers. The contribution of Ca2+-activated K+ channels to H+ sensitivity of these neurons was confirmed further in voltage-clamp experiments in which outward rectifying I-V curves were recorded that revealed a zero current potential of -70 mV. CO2/H+ induced a prominent reduction in outward currents and shifted the zero current potential to more positive membrane potentials (mean -63 mV). The CO2/H+-sensitive current reversed at -72 mV and was blocked by external application of TEA. It is concluded that CO2/H+ exerts its stimulatory effects on fetal medullary neurons by inhibition of Ca2+-activated K+ channels, either directly or indirectly, by blocking voltage-dependent Ca2+ channels, which in turn results in a reduction of K+ efflux and in cell depolarization.
Collapse
|