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Results for “Pain Perception”

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PubMed1990

Effect of early exposure to delta-9-tetrahydrocannabinol on the levels of opioid peptides, gonadotropin-releasing hormone and substance P in the adult male rat brain.

The effects of neonatal exposure to delta-9-tetrahydrocannabinol (THC) on the adult animal brain neurochemistry and pain perception were evaluated. Newborn rat pups were culled to a litter size of 8 (males and females) and treated either with THC (2 mg/kg) or oil (control) daily, during days 1-4 after birth. After weaning, the THC-treated males were housed 4 per cage. During the juvenile period (day 50), the THC-treated animals exhibited significantly lower baseline tail-flick values (a measure of pain perception) than the control. However, as adults, the THC-treated animals exhibited significantly higher sensitivity to pain following 5 mg/kg morphine challenge. Furthermore, the THC-treated animals had significantly elevated beta-endorphin and methionine-enkephalin levels in almost all the brain areas sampled for the study. In addition, the neonatally THC-treated rats exhibited significantly higher levels of substance P (SP) and significantly lower levels of gonadotropin releasing hormone (GnRH) in the anterior hypothalamus-preoptic area. The SP and GnRH levels did not differ among the THC-treated and control animals in the medial basal hypothalamus. The results of this study indicate that even a very low dose of THC administered during the neonatal period has a long-lasting effect on the brain neurochemistry. In particular, neonatal administration of THC appears to alter functioning of the endogenous opioid system.

Animals↗

PubMed1999

Peripheral coding of tonic mechanical cutaneous pain: comparison of nociceptor activity in rat and human psychophysics.

These experiments investigated temporal summation mechanisms of tonic cutaneous mechanical pain. Human volunteers provided psychophysical estimates of pain intensity, which were compared with discharge patterns of rat cutaneous nociceptors tested with identical stimulus protocols. Human subjects made either intermittent or continuous ratings of pain intensity during stimulation of the skin between the thumb and first finger. Stimulus intensities of 25, 50, and 100 g were applied with a probe of contact area of 0.1 mm(2) for 2 min. Pain perception significantly increased during stimulation (temporal summation) for the 50- and 100-g stimulus intensities. Sequential conduction block of the myelinated fibers supplying the stimulated skin was used to investigate the role of A-fiber mechanoreceptors and nociceptors in this temporal summation. Conduction block of the Abeta fibers resulted in an increase in mechanically evoked pain estimates and an increase in temporal summation, consistent with loss of Abeta-mediated inhibition. When only conduction in the unmyelinated fibers remained, pain estimates were reduced to the preblock levels, but temporal summation was still present. Electrophysiological recordings were made from filaments of the sciatic nerve supplying receptors in the plantar skin of barbiturate-anesthetized rats. Forty units fulfilled the identification criteria for nociceptors: 20 A-fiber and 20 C-fiber nociceptors. Each unit was characterized by recording its responses to graded mechanical and heat stimuli. Nociceptors were also tested with stimuli identical to those applied to the human subjects. The responses of all units to sustained mechanical stimuli were adaptive-that is, they exhibited a gradual decline in response with time. However, the time course of adaptation varied among units. All the C-fiber nociceptors and one-half of the A-fiber nociceptors had rapidly adapting responses. The remainder of the A-fibers displayed slowly adapting responses. One-third of all units also showed short-duration increases in firing rate during stimulation. The latency after stimulus onset of this rate acceleration was inversely related to stimulus intensity. Despite the apparent disparity between perceptual temporal summation and nociceptor adaptation, central and peripheral mechanisms are proposed that can reconcile the relationship between nociceptor activity and pain perception.

Adult↗

PubMedDate not supplied

Psychophysiologic and affective parameters associated with pain intensity of cardiac cardioverter defibrillator shock discharges.

OBJECTIVE: Pain caused by intracardiac shock discharge of an implanted cardioverter defibrillator (ICD) is an important clinical issue in the treatment of ICD patients. The present study aimed to examine whether the strength of perceived shock pain is influenced by affective and psychophysiologic parameters. METHODS: Among 204 ICD patients drawn from the German Heart Center Munich, 95 patients (46.6%) experienced > or =1 shock discharge. Pain perception (PPC) was measured by a visual analog scale ranged from 0 to 100 points. Standard instruments were administered to measure psychological distress. A startle paradigm was assessed to measure psychophysiologic arousal with skin conductance responses (SCR) and electromyogram responses (EMG) as dependant variables. Classification and regression tree (CART) analysis was applied to assess the effects of psychodiagnostic and psychophysiologic parameters on pain perception. RESULTS: Mean ICD shock PPC was 53.7 points (SD 31.6), with a median of 59.0 points (interquartile range 30-80). Pain intensity was highly associated with shock discomfort (p < .001) but was largely uninfluenced by clinical and sociodemographic factors. CART analysis revealed patients with one shock and low EMG magnitude (< or =4.15 muV) as subclass with the lowest mean PPC (21.9 points; 95% confidence interval [CI], 4.6-39.1), whereas patients with >one shock experience and an anxiety score >7 (Symptom Checklist-90) expressed the highest mean PPC (74.8 points; 95% CI, 60.5-89.2). Without heightened anxiety, an increased EMG amplitude and impaired EMG habituation yielded a mean PPC of 71.2 (95% CI, 61.6-80.9). CONCLUSIONS: Augmented PPC of ICD shocks is predominantly associated with the number of perceived shocks, postshock anxiety, and accompanied by heightened levels of EMG magnitude and impaired EMG habituation, which points to sensitization of central neural structures.

Acoustic Stimulation↗

PubMed1996

Good patients cope with their pain: postoperative analgesia and nurses' perceptions of their patients' pain.

Patients routinely receive less analgesia postoperatively than they need. Previous attempts to understand this have examined the nurses' attitudes to analgesia and their ability to assess accurately the intensity of their patients' pain. The present study examined three hypotheses derived from an alternative view that undermedication results from patients failing to disclose their difficulty in coping with pain because this would lead to disapproval by nurses: (i) that analgesic intake is related, not to pain intensity but to patients' feelings of being unable to cope with pain and to nurses' assessment of their inability to cope; (ii) that nurses specifically underestimate patients' ability to cope with their pain; and (iii) that poor coping with pain is seen by nurses as indicative of a 'bad' patient. Pain ratings were completed by 56 patients undergoing minor abdominal surgery; nurses completed similar scales to show their perception of patients' pain, as well as a specially devised scale which measured how negatively or positively they felt about their patients. Nurses were sensitive to the intensity of their patients' pain, but underestimated how well patients felt they coped with pain and how much they wanted analgesia. Patients who experienced the worst pain, or whom the nurses perceived as coping least well with their pain, were evaluated by the nurses as unpopular and demanding.

Adaptation, Psychological↗

PubMed2004

Effect of volume used in sub-Tenon's anaesthesia on efficacy and intraocular pressure: a randomized clinical trial of 3 mL versus 5 mL.

PURPOSE: To compare the effect of volume used in sub-Tenon's anaesthesia on efficacy and intraocular pressure (IOP). METHODS: A prospective, randomised clinical trial was conducted on 52 eyes of 52 consecutive patients undergoing sub-Tenon's anaesthetic for cataract surgery. Eyes were randomly assigned to either 3 mL or 5 mL volume of anaesthetic solution (0.5% bupivacaine/2% lidocaine in a 50:50 mixture). The main outcome measures were akinesia 5 min post-administration of anaesthetic, changes in IOP immediately after and 5 min after anaesthetic administration, and patient pain perception during procedure. RESULTS: The level of kinesia was greater in the 3 mL group (n = 25) compared to the 5 mL group (n = 27) (P = 0.001, Mann-;Whitney U-test). There was no significant difference in pain perception between the two groups (P = 0.464, student t-test). Although there was great variation in IOP changes following sub-Tenon's anaesthetic, there was a trend for a larger rise in mean IOP immediately after anaesthetic administration in the 5 mL group (mean +/- SD +5.6 +/- 4.2 mmHg) compared to the 3 mL group (+4.3 +/- 3.8 mmHg), but this did not reach statistical significance (P = 0.25, student t-test). CONCLUSIONS: A 5 mL volume of anaesthetic provides akinesia superior to a 3 mL volume in sub-Tenon's anaesthesia for cataract surgery.

Aged↗

PubMed1994

Neurophysiological studies in chronic paroxysmal hemicrania and hemicrania continua.

To explore the possible involvement of the pain control system, pain pressure threshold (PPT), nociceptive flexion reflex (RIII), blink and corneal reflexes have been studied for pain perception assessment in 12 patients with chronic paroxysmal hemicrania (CPH) and 12 patients with hemicrania continua (HC). PPT was found to be reduced in HC and CPH when separately compared to controls. In addition, a significant reduction of subjective pain perception (Tp) which was most marked on the symptomatic side, has been demonstrated after sural nerve stimulation in CPH. The RIII reflex threshold on the symptomatic side was significantly reduced when patients were compared to controls. No major differences between CPH and HC as regards blink reflex latencies were found; nor was any such difference observed when comparing the two headache groups to controls. The corneal reflex thresholds were found significantly reduced bilaterally in CPH, irrespective of whether the treatment was given or not.

Adult↗

PubMed1996

Analgesic efficacy of low-dose ketamine. Somatosensory-evoked responses in relation to subjective pain ratings.

BACKGROUND: Low-dose ketamine has been shown to exert analgesic effects. Whether ketamine-induced pain relief may be quantitated by somatosensory evoked cerebral potentials has not been established. METHODS: Thirty healthy volunteers were assigned randomly to one of three groups. Subjects of group 1 (n = 10, control) were given saline as placebo. In groups 2 (n = 10) and 3 (n = 10), intravenous ketamine (0.25 mg. kg-1 and 0.50 mg. kg-1, respectively) was administered. The following variables were recorded at baseline and for 50 min after drug administration: electroencephalographic (EEG) data, somatosensory-evoked late cortical responses (SEP) elicited by intracutaneous stimulation of the fingertip (2-3 fold pain threshold), heart rate, mean arterial blood pressure, and end-tidal PETCO2 via a tight-fitting mask. Electroencephalographic spectral power in selected frequency bands and frequency percentiles were calculated from the spontaneous EEG segment preceding each somatosensory stimulus. Somatosensory-evoked late cortical response parameters were calculated from the respective poststimulus EEG segments. After recording of each EEG response, subjects were asked to rate the individual pain sensation. RESULTS: In group 1, all variables did not change over time. Ketamine administration resulted in dose-dependent decreases in alpha-activity and increases in theta power (group 2: 190%, group 3: 440%). Electroencephalographic changes were not related to changes in pain perception. For the first 30 min after ketamine injection, a dose-dependent decrease of the long-latency N150-P250 somatosensory-evoked late cortical response component was observed (group 2: 15-20%; group 3: 25-30%). Subjective pain ratings were also different between groups, with a higher degree of pain relief in group 3 for the first 30 min. At the end of the observation period, pain relief and the N150-P250 amplitude were comparable in both ketamine groups. CONCLUSIONS: These data indicate that pain relief induced by low-dose ketamine is dose-dependent for the first 30 min after bolus injection. Changes in pain perception may be quantitated by somatosensory-evoked cortical responses. Also, EEG changes are not specific for changes in nociception, but the increase in theta power may reflect the hypnotic effect of low-dose ketamine.

Adult↗

PubMed2005

Selective ablation of nociceptive neurons for elimination of hyperalgesia and neurogenic inflammation.

OBJECT: Neuropathic pain is mediated by nociceptive neurons that selectively express the vanilloid receptor 1 (VR1). Resiniferatoxin (RTX) is an excitotoxic VR1 agonist that causes destruction of VR1-positive neurons. To determine whether RTX can be used to ablate VR1-positive neurons selectively and to eliminate hyperalgesia and neurogenic inflammation without affecting tactile sensation and motor function, the authors infused it unilaterally into the trigeminal ganglia in Rhesus monkeys. METHODS: Either RTX (three animals) or vehicle (one animal) was directly infused (20 microl) into the right trigeminal ganglion in Rhesus monkeys. Animals were tested postoperatively at 1, 4, and 7 weeks thereafter for touch and pain perception in the trigeminal distribution (application of saline and capsaicin to the cornea). The number of eye blinks, eye wipes, and duration of squinting were recorded. Neurogenic inflammation was tested using capsaicin cream. Animals were killed 4 (one monkey) and 12 (three monkeys) weeks postinfusion. Histological and immunohistochemical analyses were performed. Throughout the duration of the study, response to high-intensity pain stimulation (capsaicin) was selectively and significantly reduced (p < 0.001, RTX-treated compared with vehicle-treated eye [mean +/- standard deviation]): blinks, 25.7 +/- 4.4 compared with 106.6 +/- 20.8; eye wipes, 1.4 +/- 0.8 compared with 19.3 +/- 2.5; and squinting, 1.4 +/- 0.6 seconds compared with 11.4 +/- 1.6 seconds. Normal response to sensation was maintained. Animals showed no neurological deficit or sign of toxicity. Neurogenic inflammation was blocked on the RTX-treated side. Immunohistochemical analysis of the RTX-treated ganglia showed selective elimination of VR1-positive neurons. CONCLUSIONS: Nociceptive neurons can be selectively ablated by intraganglionic RTX infusion, resulting in the elimination of high-intensity pain perception and neurogenic inflammation while maintaining normal sensation and motor function. Analysis of these findings indicated that intraganglionic RTX infusion may provide a new treatment for pain syndromes such as trigeminal neuralgia as well as others.

Animals↗

PubMed1985

Adult perceptions of pain and hunger cries: a synchrony of arousal.

180 male and female nonparent adults rated tape-recordings of the initial, middle, and final 10-sec segments of pain and hunger cries on 4 7-point Likert-type scale items describing how urgent, arousing, aversive, and sick the cry segments sounded. Multivariate analyses of variance showed that the final segment of the pain cry was perceived as less urgent, arousing, and aversive than the initial and middle segments. The hunger cry was perceived as increasingly more urgent, arousing, and aversive from the initial to the middle to the final cry segments, with the final segment receiving higher ratings than the final segment of the pain cry. The middle segment of both cries was the most sick sounding. While females were more aroused than males as the hunger cry intensified, and females were less aroused than males as the pain cry subsided, the initial segments of the pain cry were particularly potent stimuli to both males and females. These results suggest that different segments of cries resulting from the same stimulus provide different messages that communicate the presumed level of infant arousal.

Adult↗

PubMed1998

Sexual and physical abuse in women with fibromyalgia: association with outpatient health care utilization and pain medication usage.

OBJECTIVE: To evaluate the relationship between sexual and/or physical abuse and health care usage in patients with fibromyalgia (FM) and identify variables that may influence this relationship. METHODS: We assessed history of sexual/physical abuse, health care utilization, and medication usage, as well as related variables in 75 women with FM using standardized questionnaires, structured interviews, and laboratory pain perception tasks. RESULTS: Fifty-seven percent of FM patients reported a history of sexual/physical abuse. Compared to non-abused patients, abused patients reported significantly greater utilization of outpatient health care services for problems other than FM and greater use of medications for pain (P < or = 0.025). Consistent with our expectations, abused patients also were characterized by significantly greater pain, fatigue, functional disability, and stress, as well as by a tendency to label dolorimeter stimuli as painful regardless of their intensities (P < or = 0.05). Additional analyses suggested that the high frequency of sexual/physical abuse in our patients was associated primarily with seeking health care for chronic pain rather than the FM syndrome itself or genetic factors. CONCLUSION: There is an association in FM patients between sexual/physical abuse and increased use of outpatient health care services and medications for pain. This association may be influenced by clinical symptoms, functional disability, psychiatric disorders, stress, and abnormal pain perception. The relationships among these variables should be further tested in prospective, population-based studies.

Adolescent↗

PubMed2003

Correlation between facial pain or headache and computed tomography in rhinosinusitis in Canadian and U.S. subjects.

OBJECTIVES: Objectives were 1) to determine whether a correlation exists between facial pain or headache and sinus disease severity by computed tomography (CT) scan in patients with rhinosinusitis and 2) to compare disease severity and pain perception in two geographically diverse North American patient populations. STUDY DESIGN: Prospective patient questionnaire before CT scan of the paranasal sinuses. METHODS: Patients with refractory rhinosinusitis were recruited at the University of Texas Medical Branch (Galveston, TX) and the University of Alberta (Edmonton, Alberta, Canada). Before CT scanning, patients completed a pain questionnaire. All scans were interpreted by one neuroradiologist and were scored using the Lund-McKay, Harvard, and Kennedy staging systems for rhinosinusitis. RESULTS: Fifty-one patients completed questionnaires (27 were Canadian). There was no correlation between pain severity and disease severity reflected by any of the three staging systems used (P >.05). The mean pain score for the U.S. patients was 7.3, and for Canadian patients, 5.2. The mean CT scores for U.S. versus Canadian patients were as follows: Lund-McKay, 2.6 versus 6.6; Harvard, 0.7 versus 1.0; and Kennedy, 1.4 versus 2.2. The Canadian patients had more severe disease on CT scan (Lund-McKay, P <or=.001; Harvard, P <or=.005; and Kennedy, P <or=.007) while reporting less severe pain (P <or=.004). CONCLUSIONS: There was no correlation between pain severity and disease severity by sinus CT scan as graded by the Lund-McKay, Harvard, or Kennedy staging system. Facial pain and headache, although frequent complaints of patients with rhinosinusitis, are not useful predictors of sinus disease severity. There appears to be a difference in pain perception between the two North American populations.

Adult↗

PubMed2005

Delta (delta) opioid receptors in small and medium-sized trigeminal neurons supporting the dental pulp of rats.

The control of pain perception is a challenge in clinical dentistry, most prominent during tooth pulp inflammation. The tooth pulp is a well-defined target, and is densely supplied by a sensory trigeminal innervation. Opioids are signaling molecules that are suggested to participate in pain perception. Here we analysed the presence of delta opioid receptor (DOR) in trigeminal neurons innervating the tooth pulp of rat molars. Immunohistochemical and ultrastructural analysis revealed that DOR was identified in peripheral nerves in the molar dental pulp, both in the root and the coronal pulpal parts, with branching in the highly innervated subodontoblast layer. DOR was localised in about one third of all the trigeminal dental neurons, identified by means of retrograde neuronal transport of fluorogold (FG) from the dental pulp. Of the DOR-labeled neurons, nearly all were small and medium-sized (147.5-1,810.2 microm(2), mean 749.1 +/- 327.3 microm(2)). Confocal microscopy confirmed that DOR-immunoreactivity was distributed as granules in the neuronal cytoplasm. Approximately 70% of the DOR-immunoreactive neurons were also immunopositive for vanilloid receptor 1 (TRPV1). Ultrastructural analysis demonstrated DOR-immunoreactivity in the unmyelinated and in some of the myelinated nerve fibers in the dental pulp. These results indicate that DOR may influence the function in a subset of small and medium-sized trigeminal sensory neurons supporting the tooth, which are mainly known for their ability to mediate nociceptive stimuli. Agonists, acting on DOR, may thus have an influence on a subpopulation of nociceptive neurons supporting the rat tooth.

Animals↗

PubMed2004

Differential nociceptive deficits in patients with borderline personality disorder and self-injurious behavior: laser-evoked potentials, spatial discrimination of noxious stimuli, and pain ratings.

Approximately 70-80% of women meeting criteria for borderline personality disorder (BPD) report attenuated pain perception or analgesia during non-suicidal, intentional self-mutilation. The aim of this study was to use laser-evoked potentials (LEPs) and psychophysical methods to differentiate the factors that may underlie this analgesic state. Ten unmedicated female patients with BPD (according to DSM-IV) and 14 healthy female control subjects were investigated using brief radiant heat pulses generated by a thulium laser and five-channel LEP recording. Heat pulses were applied as part of a spatial discrimination task (two levels of difficulty) and during a mental arithmetic task. BPD patients had significantly higher heat pain thresholds (23%) and lower pain ratings (67%) than control subjects. Nevertheless, LEP amplitudes were either normal (N1, P2, P3) or moderately enhanced in BPD patients (N2). LEP latencies and task performance did not differ between patients and control subjects. The P3 amplitudes, the vertex potential (N2-P2), and the N1, which is generated near the secondary somatosensory cortex, were significantly reduced during distraction by mental arithmetic in both groups. In addition, P3 amplitudes reflected task difficulty. This study confirms previous findings of attenuated pain perception in BPD. Normal nociceptive discrimination task performance, normal LEPs, and normal P3 potentials indicate that this attenuation is neither related to a general impairment of the sensory-discriminative component of pain, nor to hyperactive descending inhibition, nor to attention deficits. These findings suggest that hypoalgesia in BPD may primarily be due to altered intracortical processing similar to certain meditative states.

Adult↗

PubMed2004

[Cerebral mechanisms of hypnosis].

The neural mechanisms underlying hypnosis and especially the modulation of pain perception by hypnosis remain obscure. Using PET we first described the distribution of regional cerebral blood flow during the hypnotic state. Hypnosis relied on revivification of pleasant autobiographical memories and was compared to imaging autobiographical material in < >. The hypnotic state was related to the activation of a widespread set of cortical areas involving occipital, parietal, precentral, premotor, and ventrolateral prefrontal and anterior cingulate cortices. This pattern of activation shares some similarities with mental imagery, from which it mainly differs by the relative deactivation of precuneus. Second, we looked at the anti-nociceptive effects of hypnosis. Compared to the resting state, hypnosis reduced pain perception by approximately 50 %. The hypnosis-induced reduction of affective and sensory responses to noxious thermal stimulation were modulated by the activity in the midcingulate cortex (area 24a'). Finally, we assessed changes in cerebral functional connectivity related to hypnosis. Compared normal alertness (i.e., rest and mental imagery), the hypnotic state, significantly enhanced the functional to modulation between midcingulate cortex and a large neural network involved in sensory, affective, cognitive and behavioral aspects of nociception. These findings show that not only pharmacological but also psychological strategies for pain control can modulate the cerebral network involved in noxious perception.

Brain↗

PubMed1995

Cocaine, lidocaine, tetracaine: which is best for topical nasal anesthesia?

The quality of nasal anesthesia obtained with three local anesthetic solutions (4% cocaine, 2% lidocaine in oxymetazoline, and 1% tetracaine in oxymetazoline) was evaluated in a randomized study. Each local anesthetic mixture was applied to the nasal septum of healthy volunteers using medication-soaked pledgets. Measurements of anesthetic effect (sensation threshold and pain perception) were made with Semmes-Weinstein monofilaments. Measurements were performed prior to local anesthetic application and 10 and 70 min after local anesthetic application. Subjects had greater increases in sensation threshold with tetracaine than with lidocaine or cocaine at both 10 and 70 min (P < 0.05). Subjects had greater decreases in pain perception with tetracaine than with lidocaine or cocaine at both time intervals (P < 0.05). Tetracaine mixed with oxymetazoline appears to be a superior topical anesthetic for nasal procedures.

Adult↗

PubMed1986

Hypoalgesia induced by antidepressants in mice: a case for opioids and serotonin.

The tail flick assay was used to evaluate pain perception in mice treated acutely with either of the two classical antidepressant drugs (AD) imipramine or amitriptyline, or the atypical antidepressant iprindole. A sustained hypoalgesic effect, sensitive to the opiate antagonist naloxone, was detected for the AD used in this study. Administration of the aminopeptidase inhibitor bestatin or the enkephalinase blocker thiorphan made subeffective doses of AD hypoalgesic. This synergistic effect was reversed by naloxone. The antinociceptive action of the AD wore off in mice rendered tolerant to morphine by subcutaneous implantation of a pellet of the opiate. Subchronic treatment with p-chlorophenylalanine did not alter the effect of AD on pain perception, but in animals whose serotonin (5-HT) receptors were blocked by methysergide AD did not produce any change in pain threshold. It was concluded on the basis of these findings that short-chain opioids and 5-HT appear to have a role in the hypoalgesic effect of either classical or atypical AD.

Amitriptyline↗

PubMedDate not supplied

Use of piritramide for analgesia and sedation during peribulbar nerve block for cataract surgery.

PURPOSE: To investigate the effects of pre-block analgesia and sedation using piritramide on haemodynamic stability, endocrine stress response and patients' pain perception. METHODS: In a randomized, single-blinded, placebo-controlled study, 60 patients having cataract surgery with peribulbar block were randomly assigned into two groups: group A (n = 30) received 0.05 mg/kg piritramide (Dipidolor) intravenously; group B received normal saline intravenously prior to peribulbar block. Mean arterial pressure, heart rate, respiratory rate and pulse oximetry were recorded perioperatively. Pain from peribulbar block was assessed using a verbal analogue scale. Urinary excretion of vanillylmandelic acid was measured to assess the endocrine stress response. Using a questionnaire, patients assessed their anxiety and back pain before and during surgery. RESULTS: Mean arterial pressure remained near baseline in group A. In group B, a significant increase in mean arterial pressure after peribulbar block was found (p < 0.001). In addition, a significant increase in urinary excretion of vanillylmandelic acid was found in group B (p = 0.013). Pain scores (p < 0.001), anxiety before nerve block (p = 0.02) and during surgery (p < 0.001) and back pain (p = 0.003) were significantly lower in group A. CONCLUSION: The presented study suggests that using piritramide for analgesia and sedation prior to peribulbar block produces haemodynamic stability and reduces pain perception and endocrine stress response.

Aged↗

PubMed1998

Pressure algometry in healthy subjects: inter-examiner variability.

The purpose of this study was to estimate inter-examiner reliability of head and neck algometry. Pain perception thresholds were assessed with a mechanical pressure algometer in 21 healthy individuals. Thresholds were assessed at 13 symmetrical points on each side of the head and neck, at the deltoid muscle and at the median finger. The pressure range of the instrument proved insufficient to study the pain perception threshold on the finger, however. Two different examiners carried out one or two examinations in each subject during one day. The sequence of investigations was varied randomly. The inter-examiner reliability was found to be good, with a mean intra-class correlation coefficient (ICC) of 0.75. Intra-examiner reproducibility was excellent (mean ICC = 0.84). The mean inter-examiner coefficient of variation was 18.7%, while the mean coefficient of repeatability (CR) was 1.60 kg/cm2. In comparison, the mean intra-examiner coefficient of variation was 15% while the mean CR was 1.29 kg/cm2. Statistically significant differences between examiners were found for the frontal point (p < 0.01), while a trend towards lower thresholds in one of the two observers was seen in 10 of the 13 non-significant points. Inter-examiner reliability of side differences was excellent, with CR = 1.23 kg/cm2. In conclusion, manual algometry with a rather inexpensive mechanical device has a good to excellent inter-rater reliability. When studying patients, however, the possible bias introduced by different examiners should be taken into account, both regarding study design and data analysis.

Adult↗