Anxiety sensitivity as a predictor of labor pain.

Psychosocial factors have been implicated in the pain experience during childbirth, which can have both short- and long-term consequences on the mother's health and her relationship with her infant. The present study evaluated important demographic, social, and psychological factors as predictors of multiple dimensions of labor pain among 35 mothers during childbirth. The results indicated that anxiety sensitivity (AS), as measured by the Anxiety Sensitivity Index, shared a significant relation with maximum pain during labor as well as sensory and affective components of pain as measured by the McGill Pain Questionnaire. AS predicted both maximum pain during labor and sensory aspects of pain above and beyond demographic and social factors as well as other theoretically important psychological factors (e.g., depression and state anxiety). These data replicate previous research that has demonstrated the significant impact of AS on pain responding in other areas (e.g., chronic pain) and extend knowledge in this literature to demonstrate the important role that AS serves among women and their experience of labor pain. Clinical implications are highlighted and discussed.     

Infant Behaviors as Indicators of Established Acute Pain

ISSUES AND PURPOSE. Many infant pain assessment tools use infant behaviors indicative of increased arousal. These tools were developed and tested using clinical situations involving acute immediate pain responses. Are these behaviors valid, clinical indicators of acute established pain (non‐procedurally caused) pain? Can these tools be used to assess acute established infant pain? This article explores research findings to answer these questions. CONCLUSIONS. Findings suggest that behaviors indicative of increased arousal (e.g., crying, facial expressions that accompany crying) are nonspecific indicators of distress rather than independent indicators of established acute pain. Thus, the use of behaviors representing acute immediate pain responses to assess acute established pain, or the use of tools that incorporate these behaviors, can be misleading. PRACTICE IMPLICATIONS. Always use acute immediate pain behavioral responses (behaviors indicative of increased arousal) in conjunction with clinical data concerning “likelihood of pain“ and consolability.     

Parental response to children's pain: the moderating impact of children's emotional distress on symptoms and disability

Parental responses play a central role in the development and maintenance of children’s pain behavior. Previous studies examining the impact of parental responses on children’s pain have focused mainly on protective or solicitous responses. This study examined the impact of parental responses, including protectiveness, minimization of pain, and encouraging and monitoring responses, on children’s functional disability and somatic symptoms. Participants included 327 patients with chronic pain, ages 8–17, who completed measures of pain, disability, somatic symptoms, depression, and anxiety. Patients’ parents completed a measure assessing parental responses to their children’s pain. Results show that for children with higher levels of emotional distress, maladaptive parental responses to pain (e.g., criticism, discounting of pain, increased attention to pain, and granting of special privileges) were associated with increased disability and somatic symptoms. Results of this study demonstrate the important ways in which parents can influence how their children cope with and manage chronic pain. Children whose parents are overly protective or critical of their pain may experience more impairment or somatic symptoms, particularly those children who are already at risk for difficulties due to higher levels of emotional distress.     

Depression and changed pain perception: hints for a central disinhibition mechanism

Although patients with a depressive disorder report often of pain, their sensitivity to experimental pain is controversial, probably due to differences in sensory testing methods and to the lack of normal values. Therefore, we used a standardized and validated comprehensive sensory testing paradigm to assess the peripheral and central nervous system performance in depressive patients compared to healthy controls and chronic pain patients with fibromyalgia syndrome (FMS), in which depression is a common comorbidity. Twenty-five depressive psychiatric inpatients (pain-free: n=20), 35 FMS outpatients and 25 healthy controls underwent quantitative sensory testing (QST), including thermal and mechanical detection and pain thresholds, pain sensitivity and responsiveness to repetitive noxious mechanical stimuli (wind-up). In depressive disorder (to a lesser extent also in FMS), significantly decreased cold pain thresholds and an increased wind-up were found, although the mechanical pain thresholds and pain sensitivity were comparable to those of the healthy controls. All the detection thresholds were within the normal range in all the groups. In depressive disorder, there were no significant side differences in the detection and pain thresholds. The results contradict the former assumption of a general insensitivity to experimental pain in depressive disorder. In the mostly pain-free patients signs of an enhanced central hyperexcitability are even more pronounced than usually found in chronic pain patients (e.g. FMS), indicating common mechanisms in depressive disorder and chronic pain in accordance with the assumption of non-pain associated mechanisms in depressive disorder for central hyperexcitability, e.g. by inhibited serotonergic function. Furthermore, this trial demonstrates the feasibility of QST in depressive patients.     

Pain Sensitivity and Thermal Detection Thresholds in Young Adults Born Preterm With Very Low Birth Weight or Small for Gestational Age at Term Compared With Controls

The objective of this prospective long-term follow-up study was to investigate whether somatosensory function is altered among young adults born preterm with very low birth weight (VLBW; ≤1,500 g) or small for gestational age (SGA; <10th percentile) at term. In a blinded quantitative sensory testing protocol, we determined thermal detection, thermal pain, and pressure pain thresholds and the response to prolonged supra-threshold heat among 51 VLBW, 66 term SGA, and 86 term-born controls (birth weight ≥10th percentile) at 28 years. Self-reported chronic pain was also investigated. Except for increased sensitivity to cool in the term SGA group versus controls, we found no significant group differences regarding thermal or pain thresholds. Overall, male participants had higher pain thresholds, and no significant interactions of group and sex were observed (P > .14). Within the VLBW group, neonatal mechanical ventilation was associated with reduced sensitivity to cool, and length of mechanical ventilation correlated with lower pressure pain thresholds. The response to prolonged supra-threshold heat was similar between the groups, and the prevalence of self-reported chronic pain was not reliably different. In conclusion, low birth weight young adults were as sensitive to thermal and pain stimuli as term-born, normal birth weight controls, with the same sex differences.

Sensory dissociation in chronic low back pain: Two case reports

Patients with chronic low back pain often report that they do not perceive their painful back accurately. Previous studies confirmed that sensory dissociation and/or discrepancy between perceived body image and actual size is one of the specific traits of patients with chronic pain. Current approaches for measuring sensory dissociation are limited to two-point-discrimination or rely on pain drawings not allowing for quantitative analysis. This case study reports the sensory dissociation of two cases with chronic low back pain using a recently published test (point-to-point-test (PTP)) and a newly developed test (two-point-estimation (TPE)). Both patients mislocalized tactile stimuli delivered to the painful location compared to non-painful locations (PTP test). In addition, both patients perceived their painful lumbar region differently from non-painful sites above and below and contralateral to the painful site. TPE data showed two distinct clinical patterns of sensory dissociation: one patient perceived the two-point distance in the painful area as expanded, while the other patient perceived it as shrunk. The latter pattern of sensory dissociation (i.e., pattern shrunk) is likely to respond to sensory training. Whether enlarged patterns of sensory dissociation are more resistant to treatment remains unknown but would explain the low effectiveness of previous studies using sensory training in chronic low back pain populations. Subgrouping patients according to their sensory discrimination pattern could contribute to the choice and effectiveness of the treatment approach.     

Avoidance of affective pain stimuli predicts chronicity in patients with acute low back pain

This prospective study of acute and sub-acute low back pain (LBP) patients was conducted to assess whether attentional biases predicted chronic pain status 3 and 6 months later. The attentional biases of 100 LBP patients were assessed within 3 months of developing pain and 6 months later. Participants also completed measures associated with outcome at 3 assessment points: baseline, 3 and 6 months later. Current pain status was assessed at follow-ups. Patients were classified as those that met standard criteria for chronic pain or those who did not (i.e., the comparison group). At baseline, participants demonstrated a bias toward sensory pain words. However, biases toward sensory pain words did not differentiate those who subsequently developed chronic pain and those who did not at either follow-up. The same bias was observed 6 months later, but again it failed to distinguish between the chronic pain and comparison groups. However, subjects who developed chronic pain at both 3 (n = 22) and 6 (n = 21) months demonstrated biases away from affective pain words at baseline but not 6 months later, in comparison to other participants. These results remained significant in multivariate analyses. These findings are consistent with patterns observed in the previous research, and suggest that avoidance of emotionally laden pain-related stimuli (i.e., affective pain words) is associated with negative outcomes for LBP patients in the acute and sub-acute phase. This research suggests that attentional biases in relation to pain-related stimuli are important for the development of chronic pain, but are more complex than initially thought.     

对剖宫产新生儿抚触沐浴效果的研究

目的 研究剖宫产新生儿抚触沐浴的效果.方法 将接受不同沐浴方法的404例新生儿分为常规沐浴组和抚触沐浴组.后者在沐浴前和沐浴中给予新生儿适当的抚触.观察出生后5 d内两组新生儿沐浴前、沐浴中哭闹及拥抱反射出现情况的差异.结果 出生后第3-5天.沐浴前抚触沐浴组哭闹及拥抱反射的出现情况显著低于常规沐浴组(P<0.05);出生后第2-5天,抚触沐浴组哭闹、拥抱反射的出现率显著低于常规沐浴组(P<0.01).结论 与常规沐浴相比,抚触沐浴更容易被新生儿接受.     

Central modulation of pain

It has long been appreciated that the experience of pain is highly variable between individuals. Pain results from activation of sensory receptors specialized to detect actual or impending tissue damage (i.e., nociceptors). However, a direct correlation between activation of nociceptors and the sensory experience of pain is not always apparent. Even in cases in which the severity of injury appears similar, individual pain experiences may vary dramatically. Emotional state, degree of anxiety, attention and distraction, past experiences, memories, and many other factors can either enhance or diminish the pain experience. Here, we review evidence for "top-down" modulatory circuits that profoundly change the sensory experience of pain.     

Chronic Pain and Surgery: A Review of New Insights from Sensory Testing

ABSTRACT

Chronic pain is increasingly recognized as an undesirable outcome after surgery. Predicting risk of postoperative chronic pain, as well as chronic pain prevention or treatment, requires understanding of the processes underlying its development. Quantitative sensory testing research over the last decade has made it possible to start understanding the alterations in central pain processing associated with chronic pain and its development. Chronic pain syndromes are typically characterized by a pronociceptive state of pain processing, e.g., generalized hyperalgesia as a sign of supraspinal central sensitization and poor inhibitory or even facilitatory descending modulation. In the perioperative context, development and progression of chronic pain are accompanied by signs congruent with a shift towards a pronociceptive state. Preoperatively, hyperalgesia and poor descending inhibitory modulation appear to increase the risk of subsequent chronic pain. Postoperatively, abnormal persistence and spread of hyperalgesia, compatible with rostral neuraxial spread of central sensitization, are increasingly linked to the development and progression of chronic pain. These findings, which need further confirmation, suggest that perioperative quantitative sensory testing of pain sensitivity and pain modulation has the potential to become a valuable clinical tool for assessing risk of chronic pain development and for managing its prevention and treatment.     

Chronic pain and surgery: a review of new insights from sensory testing

Chronic pain is increasingly recognized as an undesirable outcome after surgery. Predicting risk of postoperative chronic pain, as well as chronic pain prevention or treatment, requires understanding of the processes underlying its development. Quantitative sensory testing research over the last decade has made it possible to start understanding the alterations in central pain processing associated with chronic pain and its development. Chronic pain syndromes are typically characterized by a pronociceptive state of pain processing, e.g., generalized hyperalgesia as a sign of supraspinal central sensitization and poor inhibitory or even facilitatory descending modulation. In the perioperative context, development and progression of chronic pain are accompanied by signs congruent with a shift towards a pronociceptive state. Preoperatively, hyperalgesia and poor descending inhibitory modulation appear to increase the risk of subsequent chronic pain. Postoperatively, abnormal persistence and spread of hyperalgesia, compatible with rostral neuraxial spread of central sensitization, are increasingly linked to the development and progression of chronic pain. These findings, which need further confirmation, suggest that perioperative quantitative sensory testing of pain sensitivity and pain modulation has the potential to become a valuable clinical tool for assessing risk of chronic pain development and for managing its prevention and treatment.     

Physical modalities in chronic pain management

The following conclusions can be made based on review of the evidence: There is limited but positive evidence that select physical modalities are effective in managing chronic pain associated with specific conditions experienced by adults and older individuals. Overall, studies have provided the most support for the modality of therapeutic exercise. Different physical modalities have similar magnitudes of effects on chronic pain. Therefore, selection of the most appropriate physical modality may depend on the desired functional outcome for the patient, the underlying impairment, and the patient's preference or prior experience with the modality. Certain patient characteristics may decrease the effectiveness of physical modalities, as has been seen with TENS. These characteristics include depression, high trait anxiety, a powerful others locus of control, obesity, narcotic use, and neuroticism. The effect on pain by various modalities is generally strongest in the short-term period immediately after the intervention series, but effects can last as long as 1 year after treatment (e.g., with massage). Most research has tested the effect of physical modalities on chronic low back pain and knee OA. The effectiveness of physical modalities for other chronic pain conditions needs to be evaluated more completely. Older and younger adults often experience similar effects on their perception of pain from treatment with physical modalities. Therefore, use of these modalities for chronic pain in older adults is appropriate, but special precautions need to be taken. Practitioners applying physical modalities need formal training that includes the risks and precautions for these modalities. If practitioners lack formal training in the use of physical modalities, or if modality use is not within their scope of practice, it is important to consult with and refer patients to members of the team who have this specialized training. Use of a multidisciplinary approach to chronic pain management is of value for all adults and older individuals in particular [79-81]. Historically, physical therapists have been trained to evaluate and treat patients with the range of physical modalities discussed in this article. Although members of the nursing staff traditionally have used some of these modalities (e.g. some forms of heat or cold and massage), increasing numbers of nurses now are being trained to apply more specialized procedures (e.g., TENS). Healthcare professionals must be knowledgeable about the strength of evidence underlying the use of physical modalities for the management of chronic pain. Based on the limited research evidence available (especially related to assistive devices, orthotics, and thermal modalities), it often is difficult to accept or exclude select modalities as having a potential role in chronic pain management for adults and older individuals. Improved research methodologies are needed to address physical modality effectiveness better.     

The Gly972Arg polymorphism in insulin receptor substrate-1 is associated with decreased birth weight in a population-based sample of Brazilian newborns

OBJECTIVE: We studied the association between the Gly972Arg polymorphism in insulin receptor substrate-1 (IRS-1) and birth weight in a population-based sample of Brazilian newborns. RESEARCH DESIGN AND METHODS: We studied 194 newborn children with adequate gestational age to identify the association between the Gly972Arg polymorphism and birth weight using PCR-restriction fragment length polymorphism analysis. RESULTS: The data showed that the birth weight was lower in the newborns with the Gly972Arg polymorphism in IRS-1 compared with control subjects (3,141 +/- 31.8 vs. 3,373 +/- 80.3 g, P < 0.008). The results also showed that the frequency of this polymorphism was increased in newborns with a birth weight <3,000 g (P=0.041). CONCLUSIONS: These results suggest that the genotype Gly972Arg may influence birth weight, reinforcing the hypothesis that genetically determined insulin resistance and/or reduced insulin secretion can result in impaired insulin-mediated growth in the fetus.     

Phantom Limb Pain: Elusive,Yet Real

Phantom limb pain is reported by almost all people who have had an amputation and by others who have dysfunction of their afferent nervous system pathways. Those who experience it indicate that the pain is real and that it is the body part that is “phantom.” Although this phenomenon is widely recognized, it is not well understood. The seeming incongruence of pain in a missing body part, combined with the difficulty of successfully treating this pain, result in severe chronic pain in a majority of people who have had an amputation. Treatment with drugs that reduce the number of functional sodium channels has been tried with success, as have various neurophysiological manipulations. This article addresses issues related to sensory experiences associated with phantom body parts and the treatment of pain associated with those experiences.     

The relationship between religion/spirituality and physical health, mental health, and pain in a chronic pain population

This study sought to better understand the relationship between religion/spirituality and physical health and mental health in 122 patients with chronic musculoskeletal pain. The current study conceptualized religion/spirituality as a multidimensional factor, and measured it with a new measure of religion/spirituality for research on health outcomes (Brief Multidimensional Measure of Religion/Spirituality). Pain patients' religious and spiritual beliefs appear different than the general population (e.g. pain patients feel less desire to reduce pain in the world and feel more abandoned by God). Hierarchical multiple regression analyses revealed significant associations between components of religion/spirituality and physical and mental health. Private religious practice (e.g. prayer, meditation, consumption of religious media) was inversely related to physical health outcomes, indicating that those who were experiencing worse physical health were more likely to engage in private religious activities, perhaps as a way to cope with their poor health. Forgiveness, negative religious coping, daily spiritual experiences, religious support, and self-rankings of religious/spiritual intensity significantly predicted mental health status. Religion/spirituality was unrelated to pain intensity and life interference due to pain. This study establishes relationships between religion/spirituality and health in a chronic pain population, and emphasizes that religion/spirituality may have both costs and benefits for the health of those with chronic pain.     

Functional abnormalities of the cervical cord and lower medulla and their effect on pain: observations in chronic pain patients with incidental mild Chiari I malformation and moderate to severe cervical cord compression

OBJECTIVE: Abnormalities of central sensory processing may play a role in the pathogenesis of chronic pain. The Chiari I malformation is a congenital hindbrain anomaly characterized by protrusion of the cerebellar tonsils into the upper cervical canal, with variable effects on the lower brain stem and cervical cord. The purpose of this study was to compare sensory function and pain among patients with chronic pain who had these disorders incidentally diagnosed, to assess the effect on pain in these patients in comparison with those without central nervous system disease. DESIGN: Retrospective study in which pain, mood, and sensory function in 32 patients with chronic pain who had mild Chiari I malformation were compared with that in 53 patients with chronic pain who had moderate to severe compression of the cervical spinal cord and 52 patients with chronic pain who had no apparent central nervous system disorder. Data had been collected previously as part of standard clinical assessments, including clinical neurological examinations, quantitative sensory testing, pain drawings, and psychometric testing with the Symptom Checklist 90. PATIENTS: All subjects were patients of a hospital-based pain management practice who had been accepted for treatment over a 5-year period. RESULTS: Both the Chiari I and cervical compression groups had long tract signs evident on clinical neurological examination. Quantitative sensory testing indicated elevations in the trigeminal territory among patients with Chiari I malformation and on the neck, hands, and feet in both the Chiari I and cervical compression groups. The extent of pain and mood disturbance was greatest in the Chiari I group and least in the group with no central nervous system disorder. Complex regional pain syndrome, fibromyalgia, and temporal mandibular joint disorder were more common among the Chiari I malformation group than among the other groups. CONCLUSIONS: Quantitative sensory analysis indicates sensory dysfunction associated with Chiari I malformation and cervical cord compression. The pattern of sensory abnormality is consistent with medullary dysfunction among the patients with Chiari I malformation and cervical cord dysfunction among cord compression patients. There were differences in the types and extent of pain and the associated disorders of mood observed among the cohorts defined above. These differences may be partly due to the presence and location of central sensory dysfunction.     

Adverse effects of pain on the nervous systems of newborns and young children: a review of the literature.

There are immediate and long-lasting harmful consequences to the nervous system when infants experience severe or repetitive pain. These effects are especially significant in preterm infants, who are vulnerable to neurological damage during this critical time of neurodevelopment. Painful experiences may cause structural and physiological changes within the nervous system. Repeated painful procedures may result in decreased pain thresholds and hypersensitivity to pain. Immediate harmful effects of pain include physiologic instability and increased incidence of serious complications such as intraventricular hemorrhage. Painful stressors may lead to sleep disturbances, feeding problems, and inability to self-regulate. Long-term effects of pain may include altered pain perception, chronic pain syndromes, and somatic complaints. Repetitive pain in the preterm infant may be associated with attention deficit disorders, learning disorders, and behavioral problems in later childhood. Nursing involvement with pain management is crucial to achieve positive health outcomes for high-risk infants and older children and adults who have experienced repetitive or severe pain as infants.     

Wirkung der Akupunktur auf die affektive und sensorische Schmerzbewertung

OBJECTIVES: The aim of the study was to investigate the effects of acupuncture on the affective and sensory experience of pain in chronic pain patients. Furthermore, the study tried to estimate the therapeutical benefit of acupuncture in relation to the stage of chronic pain according to the Mainz pain staging system for chronic pain (MPSS). METHODS: Patients with chronic pain syndromes who received acupuncture treatment answered a standardized pain questionnaire before and after treatment. The questionnaire included the visual-analogue-scale for the intensity of pain, the pain perception scale for the assessment of affective and sensory components of pain perception, and addressed the patients to the three stages of chronic pain (MPSS). RESULTS: From April 1997 to October 1999, patients (n = 165) suffering from chronic headache and facial pain syndromes (23%), spine associated pain syndromes (48%) or other pain conditions (29%) were subsequently included. Treatment with acupuncture showed a more pronounced reduction of the affective assessment than of the sensory assessment of pain. These effects were particularly pronounced in patients assigned to stage 3 of chronic pain (MPSS). CONCLUSIONS: Acupuncture in patients with high-stage chronic pain syndromes preferentially influences the affective dimension of pain perception. For the estimation of the overall clinical outcome of acupuncture treatment, a differentiation between affective and sensory components of pain is recommended.     

Amputation and phantom limb pain: a pain-prevention model.

Within the figure of more than 200,000 surgical amputations performed in the United States each year lies another--70% of patients experience phantom limb pain after the procedure, and 50% still experience phantom pain 5 years after surgery. Patients describe burning, stabbing, twisting, cramping, or throbbing pains in the missing part. Adding to the patient's and the anesthesia professional's conundrum has been the lack of a simple model that tissue injury produces pain. The patient with a surgical amputation who experiences phantom limb pain can have several sources for discomfort including problems from the original tissue injury or from pathology, e.g., scarring or continued cellular dysfunction resulting from diabetes, ischemia, or infection. Suboptimal prosthesis fit and tissues and joints connected to the affected part can continue to generate pain long after surgical wound healing. In addition, nonaffected tissues and joints now made to carry extra loads as a result of altered gait and balance can sustain collateral stress and damage and produce nociception. In addition to this series of problems, amputee patients remain susceptible to the pain problems experienced by the general population. There is a positive correlation between a painful limb before amputation and experiencing chronic phantom limb pain. Authors have described patients with preamputation pain who benefited from effective preemptive analgesia and experienced less phantom limb pain. CRNAs can have a significant role in providing anesthesia and analgesia services to these patients and can begin to think in terms of preventing lifelong pain.