Search results for " PAI."
showing 10 items of 3604 documents
C- and Aδ-fiber components of heat-evoked cerebral potentials in healthy human subjects
1999
Feedback-controlled laser heat was used to stimulate the hairy skin of the hand dorsum and forearm, and heat-evoked cerebral potentials were recorded at midline (Fz, Cz, Pz) and temporal (T3, T4) scalp positions. Based on data from primary afferent electrophysiology a stimulus level (40 degrees C) was chosen, which is above C-fiber heat threshold, but clearly below A delta-nociceptor heat threshold in order to excite selectively C-fibers without concomitant excitation of A delta-fibers. Feedback-controlled stepped heat stimuli to 40 degrees C elicited ultralate laser evoked potentials (LEPs) at the vertex in a high proportion of experiments (90%). Estimates of conduction velocity calculated…
Roles of capsaicin-insensitive nociceptors in cutaneous pain and secondary hyperalgesia.
2001
Polymodal nociceptors respond to mechanical, thermal and chemical stimuli. Whereas sensitivities to heat and to the irritant substance capsaicin have recently been linked via the properties of the vanilloid receptor type 1 receptor ion channel, sensitivity to noxious mechanical stimuli such as the pinpricks used in clinical neurology seems to be unrelated. We investigated the peripheral neural basis of pinprick pain using quantitative psychophysical techniques combined with selective conduction block by nerve compression and selective desensitization by topical capsaicin treatment. Complete A-fibre block by compression of the superficial radial nerve (criterion: loss of first pain sensation…
Inward currents in primary nociceptive neurons of the rat and pain sensations in humans elicited by infrared diode laser pulses
2002
Radiant heat is often used to study nociception in vivo. We now used infrared radiation generated by a diode laser stimulator (wavelength 980 nm) to investigate transduction mechanisms for noxious heat stimuli in acutely dissociated dorsal root ganglion (DRG) neurons of rats in vitro. The laser stimulator offered the unique opportunity to test whether the same stimuli also elicit pain sensations in humans. A specific heat-induced current (I(heat)) was elicited in six of 13 small DRG neurons (diameteror =30 microm) tested in the whole-cell configuration of the patch-clamp mode. Current responses in the seven heat-insensitive neurons were within the range explainable by the temperature depend…
Hypnotic hypo- and hyperalgesia: divergent effects on pain ratings and pain-related cerebral potentials.
1993
Pain ratings and pain-related cerebral potentials in response to noxious stimuli were investigated under hypnotic hypo- or hyperalgesia. Out of a sample of 50 subjects the 10 most highly hypnotizable were selected using the Stanford Hypnotic Susceptibility Scale. Phasic pain was induced by brief electrical stimuli intracutaneously applied to the subject's left middle finger. The subjects took part in three experimental sessions. The first session was without hypnosis for familiarization with the experimental surroundings. In the two other sessions, the subjects were hypnotized and given a suggestion of analgesia or hyperalgesia with respect to pain sensation in the left hand. The sequence o…
The efficacy of acupuncture in human pain models: A randomized, controlled, double-blinded study
2012
Acupuncture is frequently used to treat pain, although data supporting the analgesic efficacy from placebo-controlled studies is sparse. In order to get evidence for acupuncture analgesia we performed a study with 2 well-recognized experimental human pain models - the cold-pressor (CP) test and intradermal capsaicin injection. Fifty healthy men were included. Our study compared Traditional Chinese Medicine-based acupuncture to sham acupuncture with Streitberger placebo needles in a randomized, controlled, double-blinded trial. The primary endpoint was the reduction of mean pain intensity during 3minutes of CP test or of mean pain intensity within 10minutes after capsaicin injection. Seconda…
Respiratory Mechanics, Gastric Insufflation Pressure, and Air Leakage of the Laryngeal Mask Airway
1997
A potential risk of the laryngeal mask airway (LMA) is incomplete mask seal, which causes air leakage or insufflation of air into the stomach. The objective of the present study was to assess respiratory mechanics, quantify air leakage, and measure gastric air insufflation in patients ventilated via the LMA. Thirty patients were studied after induction of anesthesia but prior to any surgical manipulations. After the insertion of the LMA, patients were ventilated with increasing tidal volumes until one of the three following end points were reached: 1) gastric air insufflation, 2) airway pressure > 40 cm H2O, or 3) limitation of further increase in tidal volume by air leakage. The following …
Comparison of two different techniques of fibreoptic intubation
2009
BACKGROUND AND OBJECTIVE The application of analgesics and sedatives during fibreoptic intubation (FOI) may result in a transient decrease in arterial oxygen saturation.This study evaluates two different techniques of FOI and respective effects on procedural duration, arterial oxygen saturation, and coughing by the patient. METHODS Thirty-four patients received a standardized conscious sedation with fentanyl (1.5 microg kg(-1)) and midazolam (12.5 microg kg(-1)).All patients were randomly allocated to one of the following techniques: the 'vaporization' (VAP) technique included four applications of 2 ml lidocaine 2% administered through the working channel of the fibrescope supplying an oxyg…
Spinal Endocannabinoids and CB 1 Receptors Mediate C-Fiber–Induced Heterosynaptic Pain Sensitization
2009
Plastic Pain Perception Drugs and endocannabinoids acting on cannabinoid (CB) receptors have potential in the treatment of certain types of pain. In the spinal cord they are believed to suppress nociception, the perception of pain and noxious stimuli. Pernia-Andrade et al. (p. 760 ) now find that endocannabinoids, which are released in spinal cord by noxious stimulation, may promote rather than inhibit nociception by acting on CB1 receptors. Endocannabinoids not only depress transmission at excitatory synapses in the spinal cord, but also block the release of inhibitory neurotransmitters, thereby facilitating nociception.
Ketorolac, diclofenac, and ketoprofen are equally safe for pain relief after major surgery
2002
Background Ketorolac is approved for the relief of postoperative pain but concerns have been raised over a possible risk of serious adverse effects and death. Two regulatory reviews in Europe on the safety of ketorolac found the data were inconclusive and lacked comparison with other non-steroidal anti-inflammatory drugs. The aim of this study was to compare the risk of serious adverse effects with ketorolac vs diclofenac or ketoprofen in adult patients after elective major surgery. Methods This prospective, randomized multicentre trial evaluated the risks of death, increased surgical site bleeding, gastrointestinal bleeding, acute renal failure, and allergic reactions, with ketorolac vs di…
In vivo ultrasound real-time motion of the cervical spine during intubation under manual in-line stabilization: a comparison of intubation methods
2007
Background and objectiveIn emergency trauma situations, manual in-line stabilization of the cervical spine is recommended to reduce cervical spine movement during intubation. The aim of this study was to compare the effect of manual in-line stabilization during different intubation techniques on three-dimensional cervical spine movements and times to intubation.MethodsForty-eight subjects without any history of trauma, inflammatory or degenerative disorder of the cervical spine were randomly grouped, regardless of gender or age. All underwent elective surgery under general anaesthesia. Under manual in-line stabilization, laryngeal intubation with Macintosh laryngoscope, intubating laryngeal…