Pain threshold

TABLE 6.5. Exposure Time to Reach the Pain Threshold (API 521, 1982)... 

Radiation Intensity (Btuihrlffi) (kWIm ) Time to Reach Pain Threshold (s)... 

Thermal effects depend on radiation intensity and duration of radiation exposure. American Petroleum Institute s Recommended Practice 521 (1982) reviews the effects of thermal radiation on people. In Table 6.5, data on time to reach pain threshold are given. As a point of comparison, the solar radiation intensity on a clear, hot summer day is about 1 kW/m (317 Btu/hr/ft ). Criteria for thermal damage are shown in Table 6.6 (CCPS, 1989) and Figure 6.10 (Hymes 1983). 

Pain threshold reached after 8 s second degree burns after 20 s... 

I acknowledge that no guarantee has been given me as to the painlessness of the procedure. Some individuals, because of emotional makeup or low pain threshold, may experience pain. This procedure... 

Aspirin, non-acetylated salicylates, and other NSAIDs have analgesic, antipyretic, and anti-inflammatory actions. These agents inhibit cyclooxygenase (COX-1 and COX-2) enzymes, thereby preventing prostaglandin synthesis, which results in reduced nociceptor sensitization and an increased pain threshold. NSAIDs are the preferred agents for mild to moderate pain in situations that are mediated by prostaglandins (e.g., rheumatoid... 

The involvement in Project Monarch was not simply sexual. According to O Brien, the MPD would trigger a Dissociative Identity Disorder or DID. Mind control experts knew this could lead to an extraordinary high pain threshold, a heightened visual acuity and a compartmentalization of her memory which would allow for retention of detailed messages and data that she would not ordinarily comprehend. These memory compartments are what clinicians would refer to as personalities. This would allow O Brien and others like her to perform a variety of sexual and diplomatic tasks for the puppet masters in the CIA, DIA, NS A, or any of the other security agencies in the alphabet soup of government security acronyms. 

Research into the properties of opiates has provided more insights into the processes that make up psychopharmacological actions than any other class of drug this is because opiates bind to receptor sites that are affected by endorphins - the brain s indigenous opiates. These endorphins are implicated in pain thresholds, natural highs and our capacity for addiction to opiates. 

Analgesic A drug that relieves pain by raising the pain threshold. In the case of the opiates or narcotic analgesics, it also produced a feeling of well-being and tranquillity. 

The molecules that transduce noxious heat or cold are members of the transient receptor potential (TRP) receptor family. TRP proteins (Table 57-2) form tetra-meric nonselective cation channels within the plasma membrane, allowing sodium and calcium ion influx [4]. The TRPV3 channel is activated at temperatures between 31 and39°C, TRPV1 at43°C, and TRPV2 at 52-55°C. The heat pain threshold in humans is 43°C, suggesting that... 

Pain is always subjective thus pain is best diagnosed based on patient description, history, and physical exam. A baseline description of pain can be obtained by assessing PQRST characteristics (palliative and provocative factors, quality, radiation, severity, and temporal factors). Attention should be given to mental factors that may lower the pain threshold (anxiety, depression, fatigue, anger, fear). Behavioral, cognitive, social, and cultural factors may also affect the pain experience. 

When pain thresholds are determined by other methods involving, for example, the application of measurable pressure to the calf of the leg, the range of variability is several-fold.17 No one method can be expected to give a complete picture of the pain thresholds, much less the more subtle matter of pain sensitivities. Presumably tests for the pain-inducing effect of heat applied to intestinal tissue of different individuals would yield uniformly negative results, but this, of course, does not mean that individuals are uniform in their pain sensitivity. 

Signals from pain receptors are transmitted to the brain where they are processed in the thalamus and then passed on to the sensory cortex where the sensation of pain originates. Receptors for endorphins (and for the opiates) are abundant in these regions and it is likely that a natural role of endorphins is to interfere with the transmission of impulses through these regions. The opiates appear to do the same, acting not so much to alter the pain threshold but altering the patient s attitude to pain. 

Neuroanatomically both the locus coeruleus and the raphe nuclei project to the spinal cord where they gate sensory pathways from the skeletomuscular areas. As there is evidence that both noradrenaline and 5-HT are dysfunctional in depression, it is perhaps not surprising to find that the pain threshold is often reduced in patients with depression. Conversely, different types of antidepressants have been shown to have an antinociceptive effect in both rodent models of neuropathic pain, and clinically in fibromyalgia, chronic fatigue syndrome, postherpetic neuralgia and diabetic neuropathy. In general, it would appear that the dual action antidepressants (such as the TCAs and SNRIs) are more effective than the SSRIs. 

R in (LI) Intraperitoneal dose (mg/kg) Per cent increase in pain threshold... 

Thiopental and methohexital belong to the barbiturates which, depending on dose, produce sedation, sleepiness, or anesthesia. Barbiturates lower the pain threshold and thereby facilitate defensive reflex movements they also depress the respiratory center. Barbiturates are frequently used for induction of anesthesia. 

Mechanism of Action An opioid agonist that binds to opioid receptors in the CNS, reducing stimuli from sensory nerve endings and inhibiting ascending pain pathways. Therapeutic Effect Alters pain reception and increases the pain threshold. Pharmacokinetics ... 

Gintzler JH, Bohan M Pain thresholds are elevated during pseudopregnancy. Brain Res 507 312-316, 1990... 

Analgesia Morphine produces analgesia by elevation of pain threshold, thereby reducing the perception of pain. It also altered psychic reaction to pain which maybe associated with feeling of well being e.g. euphoria. It also produces lethargy and sleep, morphine relieves all types of pain, but dull constant pain is relieved more ef-... 

Non-steroidal antiinflammatory drugs (NSAIDs) are also known as nonopioid analgesics. They relieve pain without interacting with opioid receptors and do not depress CNS and have no drug dependence or drug abuse property and possess antipyretic activity also. They act primarily on peripheral pain mechanisms and also in CNS to raise pain threshold. 

It is a para-amino phenol derivative, acts on CNS to produce analgesia and antipyretic effect. It has negligible antiinflammatory action peripherally in therapeutic uses. It is poor inhibitor of PG synthesis in peripheral tissues, but more active on COX in brain. It also raises the pain threshold. 

Some of the unusual features of folic acid noled by investigators include (I) folic acid antagonists used in cancer therapy with temporary remissions (2) lolic acid occurs in chromosomes (3) folic acid is distributed throughout cells (4) needed for mitotic step metaphase to anaphase (5) antibody formation decreased in lolic acid deficiency (6) choline-sparing effects (7) analgesic in humans—pain threshold is increased (8) antisulfonatnide effects (9) enterohepatic circulation of folate (10) synthesized by psittacosis virus (11) concentrated in spinal fluid. 

By modifying the central reception of pain by blocking the facilitating reflexes and thereby raising the pain threshold with analgesic drugs... 

Barbiturates do not raise the pain threshold and have no analgesic property. In anesthetic doses, they depress all areas of the CNS, including the hypothalamic thermoregulatory system, respiratory center, and vasomotor centers, as well as the polysynaptic pathways in the spinal column. In addition, some, such as phenobarbital, but not all, are anticonvulsants. In toxic doses, barbiturates cause oliguria. 

The increased vigilance of legal authorities to crack down on prescription drug abuse has led to situations where patients are afraid to ask for sufficient pain medication for fear of being seen as an addict or someone with a low pain threshold. Many physicians are afraid to prescribe opioids because they are required by law to record and justify all narcotic analgesic prescriptions. 

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