The relationship to pain level of extent of injury (as measured by number of teeth extracted) and... more The relationship to pain level of extent of injury (as measured by number of teeth extracted) and attention paid to the injury (as measured by frequency of pain ratings) was studied in patients with dental postoperative pain. Patients had either 2 or 4 impacted wisdom teeth removed and rated their pain either 2 or 5 times during the experiment. A positive correlation was found between extent of injury and reported pain level as well as between frequency of pain rating and pain level. The correlation between frequency of pain rating and pain level was found only in patients with 4 teeth extracted. To our knowledge, this is the first study which quantitatively evaluates the relationship between amount of injury and level of pain. This study also suggests that the degree to which manipulations of psychological variables alter an individual's pain perception may depend on the extent of injury.
In the past two decades there has been remarkable progress in understanding the neural mechanisms... more In the past two decades there has been remarkable progress in understanding the neural mechanisms of pain. However, chronic pain is poorly understood and, by definition, poorly managed. In addition to hyperactivity of the sympathetic nervous system and damage to normal inhibitory mechanisms, social and psychological factors play a major role in producing the disability of chronic pain. New approaches to manage chronic pain include nonopiate drugs, transcutaneous electral nerve stimulation and psychological and behavioral methods. A nervous system network has recently been described that suppresses pain. This analgesic action is mediated by endogenous opioid peptides (endorphins) and by biogenic amines. The analgesia network can be activated either by electral stimulation or by opiates such as morphine or methadone.
Table I lists some of the neural mechanisms thought to contribute to neuropathic pain. More than ... more Table I lists some of the neural mechanisms thought to contribute to neuropathic pain. More than one pain generating mechanism is likely to be operative in an individual patient. It is also likely that even in patients with the same diagnosis, different pain generating mechanisms contribute to different degrees. For example, some patients with post herpetic neuralgia (PHN) have lancinating pain, minimal sensory deficit, cutaneous hyperalgesia and allodynia. Other PHN patients have constant pain, virtually complete cutaneous anesthesia and no cutaneous hypersensitivity. While many PHN patients may have a mixture of these two types of sensory abnormalities it seems likely that the pain associated with each type of abnormality has a distinct mechanism. In support of this concept, PHN associated with profound sensory loss appears to be less responsive to currently available treatments66~ If there are multiple mechanisms involved in generating neuropathic pain, it is likely that a variet...
... In the initial stages of RSD/CRPS, pain and swelling from the injury do not subside but actua... more ... In the initial stages of RSD/CRPS, pain and swelling from the injury do not subside but actually intensify (3), typically spreading from the site of the injury to other parts of the limb, to the contralateral limb, or to remote regions of the body. ...
The effects of placebo and varying doses of intravenous morphine were studied in 74 patients. All... more The effects of placebo and varying doses of intravenous morphine were studied in 74 patients. All patients underwent extraction of impacted mandibular third molars. Two hours after onset of anesthesia all patients received a placebo (intravenous saline). One hour after the placebo administration each patient received either a second placebo or, 4, 6, 8 or 12 mg of morphine, double blind, via a hidden intravenous line. Pain level was evaluated 50 min after morphine administration using a visual analog scale. Pooled data from all patients produced a dose-response curve asymptotic by 8 mg. The mean pain relief following the second placebo was found to be between that obtained following hidden administration of 4 and 6 mg of morphine. When pain level reports for individuals were plotted two unexpected features appeared. First, no patient reported complete relief, even at the highest dose of morphine (12 mg). Second, pain level reports 50 min following each dose of morphine tended to be in two clusters. Within each cluster the average pain was independent of the dose of morphine administered. However, in groups receiving progressively higher doses of morphine, the percentage of patients within the low pain level cluster increased. These latter observations are most consistent with the concept that there is a step component for narcotic analgesia.
The relationship to pain level of extent of injury (as measured by number of teeth extracted) and... more The relationship to pain level of extent of injury (as measured by number of teeth extracted) and attention paid to the injury (as measured by frequency of pain ratings) was studied in patients with dental postoperative pain. Patients had either 2 or 4 impacted wisdom teeth removed and rated their pain either 2 or 5 times during the experiment. A positive correlation was found between extent of injury and reported pain level as well as between frequency of pain rating and pain level. The correlation between frequency of pain rating and pain level was found only in patients with 4 teeth extracted. To our knowledge, this is the first study which quantitatively evaluates the relationship between amount of injury and level of pain. This study also suggests that the degree to which manipulations of psychological variables alter an individual's pain perception may depend on the extent of injury.
In the past two decades there has been remarkable progress in understanding the neural mechanisms... more In the past two decades there has been remarkable progress in understanding the neural mechanisms of pain. However, chronic pain is poorly understood and, by definition, poorly managed. In addition to hyperactivity of the sympathetic nervous system and damage to normal inhibitory mechanisms, social and psychological factors play a major role in producing the disability of chronic pain. New approaches to manage chronic pain include nonopiate drugs, transcutaneous electral nerve stimulation and psychological and behavioral methods. A nervous system network has recently been described that suppresses pain. This analgesic action is mediated by endogenous opioid peptides (endorphins) and by biogenic amines. The analgesia network can be activated either by electral stimulation or by opiates such as morphine or methadone.
Table I lists some of the neural mechanisms thought to contribute to neuropathic pain. More than ... more Table I lists some of the neural mechanisms thought to contribute to neuropathic pain. More than one pain generating mechanism is likely to be operative in an individual patient. It is also likely that even in patients with the same diagnosis, different pain generating mechanisms contribute to different degrees. For example, some patients with post herpetic neuralgia (PHN) have lancinating pain, minimal sensory deficit, cutaneous hyperalgesia and allodynia. Other PHN patients have constant pain, virtually complete cutaneous anesthesia and no cutaneous hypersensitivity. While many PHN patients may have a mixture of these two types of sensory abnormalities it seems likely that the pain associated with each type of abnormality has a distinct mechanism. In support of this concept, PHN associated with profound sensory loss appears to be less responsive to currently available treatments66~ If there are multiple mechanisms involved in generating neuropathic pain, it is likely that a variet...
... In the initial stages of RSD/CRPS, pain and swelling from the injury do not subside but actua... more ... In the initial stages of RSD/CRPS, pain and swelling from the injury do not subside but actually intensify (3), typically spreading from the site of the injury to other parts of the limb, to the contralateral limb, or to remote regions of the body. ...
The effects of placebo and varying doses of intravenous morphine were studied in 74 patients. All... more The effects of placebo and varying doses of intravenous morphine were studied in 74 patients. All patients underwent extraction of impacted mandibular third molars. Two hours after onset of anesthesia all patients received a placebo (intravenous saline). One hour after the placebo administration each patient received either a second placebo or, 4, 6, 8 or 12 mg of morphine, double blind, via a hidden intravenous line. Pain level was evaluated 50 min after morphine administration using a visual analog scale. Pooled data from all patients produced a dose-response curve asymptotic by 8 mg. The mean pain relief following the second placebo was found to be between that obtained following hidden administration of 4 and 6 mg of morphine. When pain level reports for individuals were plotted two unexpected features appeared. First, no patient reported complete relief, even at the highest dose of morphine (12 mg). Second, pain level reports 50 min following each dose of morphine tended to be in two clusters. Within each cluster the average pain was independent of the dose of morphine administered. However, in groups receiving progressively higher doses of morphine, the percentage of patients within the low pain level cluster increased. These latter observations are most consistent with the concept that there is a step component for narcotic analgesia.
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