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ABSTRACT: Voltage-gated sodium channels (Nav) are essential for the generation and conduction of action potentials. Peripheral inflammation increases the expression of Nav1.7 and Nav1.8 in dorsal root ganglion (DRG) neurons, suggesting that they participate in the induction and maintenance of chronic inflammatory pain. However, how Nav1.7 and Nav1.8 are regulated in the DRG under inflammatory pain conditions remains unclear. Using a complete Freund's adjuvant (CFA)-induced chronic inflammatory pain model and Western blot analysis, we found that phosphorylated Akt (p-Akt) was significantly increased in the ipsilateral L4/5 DRGs of rats on days 3 and 7 after intraplantar CFA injection. Immunohistochemistry showed that the percentage of p-Akt-positive neurons in the DRG was also significantly increased in the ipsilateral L4/5 DRGs at these time points. Moreover, CFA injection increased the colocalization of p-Akt with Nav1.7 and Nav1.8 in L4/5 DRG neurons. Pretreatment of rats with an intrathecal injection of Akt inhibitor IV blocked CFA-induced thermal hyperalgesia and CFA-induced increases in Nav1.7 and Nav1.8 in the L4/5 DRGs on day 7 after CFA injection. Our findings suggest that the Akt pathway participates in inflammation-induced upregulation of Nav1.7 and Nav1.8 expression in DRG neurons. This participation might contribute to the maintenance of chronic inflammatory pain. PERSPECTIVE: This article presents that inhibition of Akt blocks CFA-induced thermal hyperalgesia and CFA-induced increases in dorsal root ganglion Nav1.7 and Nav1.8. These findings have potential implications for use of Akt inhibitors to prevent and/or treat persistent inflammatory pain.
The journal of pain: official journal of the American Pain Society 04/2013; · 3.78 Impact Factor
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ABSTRACT: Protein translation controlled through activation of mammalian target of rapamycin (mTOR) participates in many physiological and pathological processes. However, whether such activation is required for chronic pain is still unknown. Here, we examined activation of the mTOR signaling pathway during complete Freund's adjuvant (CFA)-induced chronic inflammatory pain and L5 spinal nerve ligation (SNL)-induced neuropathic pain in rats. Western blot analysis showed significantly increased levels of phosphorylated mTOR (p-mTOR) and phosphorylated p70S6 kinase 1 (p-S6K1, a downstream effector of mTOR) in the ipsilateral L4/5 spinal cord 2h, 1 day, 3 days, and 7 days after intraplantar CFA injection and in the ipsilateral L4/5 dorsal root ganglions (DRGs) 1 and 3 days after CFA injection. Immunohistochemistry also demonstrated increases in number of p-mTOR-labeled neurons in the ipsilateral L4/5 DRGs and in density of p-mTOR-labeled immunoreactivity in the ipsilateral L4/5 superficial dorsal horn 1 day after CFA injection. Moreover, intrathecal administration of rapamycin, a selective inhibitor of mTOR, significantly blocked CFA-induced mechanical allodynia and thermal hyperalgesia 1 day post-CFA injection. Interestingly, expression of neither p-mTOR nor p-S6K1 was markedly altered on days 3, 7, or 14 after L5 SNL in L5 spinal cord or DRG. These findings indicate that in DRG and spinal cord, mTOR and S6K1 are activated during chronic inflammatory pain, but not during neuropathic pain. Our results strongly suggest that mTOR and its downstream pathway contribute to the development of chronic inflammatory pain.
Brain research 04/2013; · 2.46 Impact Factor
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ABSTRACT: Many drugs used for anesthesia and analgesia in children are administered "off-label." We undertook an audit of drugs commonly used for pediatric anesthesia to determine which drugs have United States Food and Drug Administration (FDA) labeling for pediatric use, which drugs are age-restricted, and which have no labeling for pediatric use.
We identified drugs administered during anesthesia to pediatric patients from the operating room pharmacy. FDA approval and indications were determined by using the Thomson Micromedex® online database. Drugs without FDA approval for pediatric use were further examined for strength of evidence and strength of recommendation for their listed indications in the database. We then examined the rate of off-label drug administration to patients younger than the age of 18 years between July 1, 2010, and August 31, 2011.
One hundred six drugs were identified. Thirty-six (34%) were not FDA-labeled for use in any pediatric age group, 40 (38%) were FDA-labeled for use in all pediatric age groups, and 30 (28%) were FDA-labeled for use in only specific age groups. Drugs were administered off-label in 73.4% of cases. Of those not labeled for any pediatric age group, some were among the most commonly used drugs in pediatric anesthesia, including neostigmine, hydromorphone, and dopamine.
Many drugs used for children during anesthesia continue to lack FDA labeling for pediatric use. Off-label use of these drugs is an accepted practice that is considered superior to the alternative of withholding needed medications. Studies are still needed to determine the safety and efficacy of drugs that lack FDA labeling for this vulnerable patient population.
Anesthesia and analgesia 03/2012; 115(5):1148-54. · 3.08 Impact Factor
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ABSTRACT: Cumulating evidence has demonstrated that μ opioid receptor (MOR) agonists promote spinal glial activation, lead to synthesis and release of proinflammatory cytokines and chemokines, and contribute to opioid-induced hyperalgesia and development of opioid tolerance and dependence. However, whether these MOR agonists directly or indirectly act on spinal cord astrocytes and microglial cells in vivo is unclear. In the present study, by combining the techniques of in-situ hybridization of MOR mRNA with immunohistochemistry of glial fibrillary acidic protein (GFAP; an astrocyte marker) and Iba1 (a microglial marker), we examined expression and distribution of GFAP, Iba1, and MOR mRNA in the spinal cord of rats under chronic morphine tolerance conditions. Intrathecal injections of morphine twice daily for 7 days reduced morphine analgesic effect and increased both GFAP and Iba1 immunostaining densities in the spinal cord. Surprisingly, neither GFAP nor Iba1 colocalized with MOR mRNA in spinal cord cells. Our findings indicate that MOR expression is absent from spinal cord astrocytes and microglia, suggesting that these cell types are indirectly activated by MOR agonists under chronic opioid tolerance conditions.
Neuroreport 02/2012; 23(6):378-84. · 1.66 Impact Factor
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ABSTRACT: Mammalian target of rapamycin (mTOR) controls mRNA translation and is critical for neuronal plasticity. However, how it participates in central sensitization underlying chronic pain is unclear. Here, we show that NMDA receptors are required for the functional role of spinal cord mTOR in bone cancer pain induced by injecting prostate cancer cells (PCCs) into the tibia. Intrathecal rapamycin, a specific mTOR inhibitor, dose dependently attenuated the development and maintenance of PCC-induced mechanical allodynia and thermal hyperalgesia. Rapamycin alone did not affect locomotor activity and acute responses to thermal or mechanical stimuli. Phosphorylation of mTOR and p70S6K (a downstream effector) was increased time dependently in L(4-5) dorsal horn and transiently in L(4-5) dorsal root ganglions on the ipsilateral side after PCC injection, although total expression of mTOR or p70S6K was not changed in these regions. The increases in dorsal horn were abolished by intrathecal infusion of DL-AP5, an NMDA receptor antagonist. Moreover, NMDA receptor subunit NR1 colocalized with mTOR and p70S6K in dorsal horn neurons. These findings suggest that PCC-induced dorsal horn activation of the mTOR pathway participates in NMDA receptor-triggered dorsal central sensitization under cancer pain conditions. PERSPECTIVE: The present study shows that inhibition of spinal mTOR blocks cancer-related pain without affecting acute pain and locomotor function. Given that mTOR inhibitors are FDA-approved drugs, mTOR in spinal cord may represent a potential new target for preventing and/or treating cancer-related pain.
The journal of pain: official journal of the American Pain Society 02/2012; 13(4):338-49. · 3.78 Impact Factor
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ABSTRACT: Surgery of the posterior fossa often produces intense postoperative pain. However, this pain is infrequently treated because of concern that opioid administration may mask the postoperative neurologic examination and/or produce hypercarbia. In this prospective, randomized controlled trial, we sought to determine whether IV patient-controlled analgesia (PCA) would lead to reductions in postoperative pain after neurosurgical procedures of the posterior fossa compared with conventional IV nurse-administered as-needed (PRN) therapy.
Eighty patients (age range, 18-82 years) undergoing elective posterior fossa surgery were randomized to receive postoperative IV fentanyl PRN 25 to 50 μg every 30 minutes or via PCA 0.5 μg/kg/dose, with a maximal dose limit of 50 μg, and 15-minute lockout (4 doses/hour). We measured pain (Numerical Rating Scale, 0-10), analgesic use, sedation (Ramsay Sedation Scale and Glasgow Coma Scale), respiration, hemodynamics, and adverse events hourly.
Sixty-five patients completed the study. Thirty-one patients received IV PCA and 34 received PRN analgesia. Patient demographics did not differ between groups. Patients in the PCA group reported less pain at rest (mean [95% confidence interval]: 3.7 [3.0, 4.4] vs 5.2 [4.5, 5.8], P = 0.003) and received more fentanyl (mean [95% confidence interval]: 54.8 [42.1, 67.6] vs 29.9 [24.2, 35.7] μg/h, P = 0.002) than those in the PRN group. There were no differences in side effects and no adverse events related to analgesic therapy.
IV PCA use resulted in reduction in postoperative pain compared with PRN analgesic therapy after surgery of the posterior fossa. Larger studies will be required to determine the safety of IV PCA in this patient population.
Anesthesia and analgesia 12/2011; 114(2):416-23. · 3.08 Impact Factor
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ABSTRACT: Opioid-induced side effects, such as pruritus, nausea, and vomiting are common and may be more debilitating than pain itself. A continuous low-dose naloxone infusion (0.25 μg/kg/h) ameliorates some of these side effects in many but not all patients without adversely affecting analgesia. We sought to determine the optimal dose of naloxone required to minimize opioid-induced side effects and to measure plasma morphine and naloxone levels in a dose escalation study.
Fifty-nine pediatric patients (24 male/35 female; average age 14.2 ± 2.2 years) experiencing moderate to severe postoperative pain were started on IV patient-controlled analgesia morphine (basal infusion 20 μg/kg/h, demand dose 20 μg/kg, 5 doses/h) and a low-dose naloxone infusion (initial cohort: 0.05 μg/kg/h; subsequent cohorts: 0.10, 0.15, 0.25, 0.40, 0.65, 1, and 1.65 μg/kg/h). If 2 patients developed intolerable nausea, vomiting, or pruritus, the naloxone infusion was increased for subsequent patients. Dose/treatment success occurred when 10 patients had minimal side effects at a naloxone dose. Blood samples were obtained for measurement of plasma morphine and naloxone levels after initiation of the naloxone infusion, processed, stored, and measured by tandem mass spectrometry with electrospray positive ionization.
The minimum naloxone dose at which patients were successfully treated with a <10% side effect/failure rate was 1 μg/kg/h; cohort size varied between 4 and 11 patients. Naloxone was more effective in preventing pruritus than nausea and vomiting. Concomitant use of supplemental medicines to treat opioid-induced side effects was required at all naloxone infusion rates. Plasma naloxone levels were below the level of assay quantification (0.1 ng/mL) for infusion rates ≤0.15 μg/kg/h. At rates >0.25 μg/kg/h, plasma levels increased linearly with increasing infusion rate. In each dose cohort, patients who failed therapy had comparable or higher plasma naloxone levels than those levels measured in patients who did not fail treatment. Plasma morphine levels ranged between 3.52 and 172 ng/mL, and >90% of levels ranged between 10.2 and 61.6 ng/mL. Plasma morphine levels were comparable between patients who failed therapy and those patients who achieved symptom control.
Naloxone infusion rates ≥1 μg/kg/h significantly reduced, but did not eliminate, the incidence of opioid-induced side effects in postoperative pediatric patients receiving IV patient-controlled analgesia morphine. Patients who failed therapy generally had plasma naloxone and morphine levels that were comparable to those who had good symptom relief suggesting that success or failure to ameliorate opioid-induced side effects was unrelated to plasma levels.
Anesthesia and analgesia 09/2011; 113(4):834-42. · 3.08 Impact Factor
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ABSTRACT: The mechanisms underlying neuropathic pain induction are very complex but might involve abnormal spontaneous activity in the sensory dorsal root ganglion (DRG). Voltage-gated sodium channels in the DRG are essential for the genesis of abnormal spontaneous neuronal activity. In this study, we examined the changes in expression of the voltage-gated sodium channel Nav1.1 in the DRG after peripheral nerve injury. Western blot analysis showed that the level of Nav1.1 protein in the ipsilateral L5 DRG was significantly increased on Days 3 and 7 after fifth lumbar spinal nerve ligation. Immunohistochemical study further confirmed a marked increase in the percentage of Nav1.1-positive cells in the ipsilateral DRG on Day 3 after fifth lumbar spinal nerve ligation. Similarly, on Day 7 after sciatic nerve axotomy, the amount of Nav1.1 protein and the percentage of Nav1.1-positive cells in the ipsilateral L5 DRG were also significantly increased. Our results suggest that an early increase in DRG Nav1.1 expression after peripheral nerve injury might be involved in the induction of neuropathic pain.
The Anatomical Record Advances in Integrative Anatomy and Evolutionary Biology 06/2011; 294(8):1406-11. · 1.47 Impact Factor
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ABSTRACT: As the cystic fibrosis (CF) population has aged, many chronic health problems have emerged, including diabetes mellitus and osteoporosis. Previous studies have suggested that pain is common in patients with CF; however, little is known about the factors associated with it or its impact on clinical outcomes. We hypothesized that pain is common, is associated with psychologic distress, and adversely affects clinical outcomes.
From February 1, 2008, to April 3, 2008, adults with CF from Johns Hopkins Hospital were surveyed about their pain. Outcomes were assessed for 12 months following survey completion. Bivariate analyses were performed using Wilcoxon log rank, Kruskal-Wallis tests, and Spearman correlations. Logistic regression models and Cox proportional hazard models were used to analyze clinical outcomes.
Eighty-three patients (61%) completed the survey. Eighty-two percent of patients reported pain within the past month, the most common sites being the head, sinuses, back, and chest. Pain frequently interfered with general activities (41.9%), mood (56.8%), and work (47.3%). Symptoms of depression and anxiety, as well as lower quality-of-life (QOL) scores, were associated with the presence of pain (P < .05 for each). The risk of pulmonary exacerbations was increased in patients with higher levels of pain, even after adjusting for FEV(1) and age (OR = 1.65; P = .038; 95% CI, 1.03-2.64). Additionally, the risk of death was higher in patients with higher average pain scores (HR = 2.28; P = .008; 95% CI = 1.2-4.2).
Pain is common in adults with CF, interferes with activities, and is associated with lower QOL and an increased risk of both exacerbations and death.
Chest 06/2011; 140(6):1598-603. · 5.25 Impact Factor
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ABSTRACT: Spinal cord glutamate transporters clear synaptically released glutamate and maintain normal sensory transmission. However, their ultrastructural localization is unknown. Moreover, whether and how they participate in inflammatory pain has not been carefully studied.
Immunogold labeling with electron microscopy was carried out to characterize synaptic and nonsynaptic localization of glutamate transporters in the superficial dorsal horn. Their expression and uptake activity after formalin- and complete Freund's adjuvant (CFA)-induced inflammation were evaluated by Western blot analysis and glutamate uptake assay. Effects of intrathecal glutamate transporter activator (R)-(-)-5-methyl-1-nicotinoyl-2-pyrazoline and inhibitors (DL-threo-β-benzyloxyaspartate [TBOA], dihydrokainate, and DL-threo-β-hydroxyaspartate), or TBOA plus group III metabotropic glutamate receptor antagonist (RS)-α-methylserine-O-phosphate, on formalin- and CFA-induced inflammatory pain were examined.
In the superficial dorsal horn, excitatory amino acid carrier 1 is localized in presynaptic membrane, postsynaptic membrane, and axonal and dendritic membranes at nonsynaptic sites, whereas glutamate transporter-1 and glutamate/aspartate transporter are prominent in glial membranes. Although expression of these three spinal glutamate transporters was not altered 1 h after formalin injection or 6 h after CFA injection, glutamate uptake activity was decreased at these time points. Intrathecal (R)-(-)-5-methyl-1-nicotinoyl-2-pyrazoline had no effect on formalin-induced pain behaviors. In contrast, intrathecal TBOA, dihydrokainate, and DL-threo-β-hydroxyaspartate reduced formalin-evoked pain behaviors in the second phase. Intrathecal TBOA also attenuated CFA-induced thermal hyperalgesia at 6 h after CFA injection. The antinociceptive effects of TBOA were blocked by coadministration of (RS)-α-methylserine-O-phosphate.
Our findings suggest that spinal glutamate transporter inhibition relieves inflammatory pain through activation of inhibitory presynaptic group III metabotropic glutamate receptors.
Anesthesiology 02/2011; 114(2):412-23. · 5.36 Impact Factor
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ABSTRACT: Protein interacting with C Kinase 1 (PICK1), a PDZ domain-containing scaffolding protein, interacts with multiple different proteins in the mammalian nervous system and is believed to play important roles in diverse physiological and pathological conditions. In this study, we report that PICK1 is expressed in neurons of the dorsal root ganglion (DRG) and spinal cord dorsal horn, two major pain-related regions. PICK1 was present in approximately 29.7% of DRG neurons, most of which were small-less than 750 μm(2) in cross-sectional area. Some of these PICK1-positive cells co-labeled with isolectin B4 or calcitonin-gene-related peptide. In the dorsal horn, PICK1 immunoreactivity was concentrated in the superficial dorsal horn, where it was prominent in the postsynaptic density, axons, and dendrites. Targeted disruption of PICK1 gene did not affect basal paw withdrawal responses to acute noxious thermal and mechanical stimuli or locomotor reflex activity, but it completely blocked the induction of peripheral nerve injury-induced mechanical and thermal pain hypersensitivities. PICK1 appears to be required for peripheral nerve injury-induced neuropathic pain development and to be a potential biochemical target for treating this disorder.
Molecular Pain 01/2011; 7:11. · 3.53 Impact Factor
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ABSTRACT: Many drugs used in the pediatric intensive care unit are administered "off label," i.e., they have been neither thoroughly tested for efficacy and safety nor approved for use in children. The U.S. Congress has enacted legislation to promote standards and requirements for Food and Drug Administration labeling for drugs used in pediatrics. Nevertheless, we hypothesized that most medications used in our pediatric intensive care unit were not Food and Drug Administration approved for use in pediatric patients.
A list of medications dispensed in the pediatric intensive care unit from January through February 2008 was obtained from our pharmacy database. We then determined whether each medication had been granted Food and Drug Administration approval for use in children. Medications were divided into the following categories: not approved for use in any pediatric age group, approved for use in limited age groups only, and approved for use in all pediatric age groups.
A pediatric intensive care unit at a tertiary care hospital with 26 beds and 1,500 admissions per year.
In the 2-month period, 248 different medications were dispensed with a total of 49,707 medication orders. Sixty (24.2%) of the medications dispensed were not Food and Drug Administration approved for use in any pediatric age group, 106 (42.7%) were approved for use in limited age groups, and 82 (33%) were approved for use in all pediatric age groups. Eleven of the 25 most frequently dispensed medications were approved for use in limited age groups, but none of them was used for the indication or age group for which they were approved.
Despite the efforts of Congress, 67% of medications prescribed and administered in the pediatric intensive care unit did not have Food and Drug Administration approval or had only limited approval, underscoring the need for the medical community to demand oversight and research to improve drug labeling for our patient population.
Pediatric Critical Care Medicine 11/2010; 12(5):e195-9. · 3.13 Impact Factor
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ABSTRACT: Protein interacting with C kinase 1 (PICK1) is a PDZ-containing protein that binds to AMPA receptor (AMPAR) GluR2 subunit and protein kinase Cα (PKCα) in the central neurons. It functions as a targeting and transport protein, presents the activated form of PKCα to synaptic GluR2, and participates in synaptic AMPAR trafficking in the nervous system. Thus, PICK1 might be involved in many physiological and pathological processes triggered via the activation of AMPARs. We report herein that PICK1 knockout mice display impaired mechanical and thermal pain hypersensitivities during complete Freund's adjuvant (CFA)-induced inflammatory pain maintenance. Acute transient knockdown of spinal cord PICK1 through intrathecal injection of PICK1 antisense oligodeoxynucleotide had a similar effect. In contrast, knockout and knockdown of spinal cord PICK1 did not affect incision-induced guarding pain behaviors or mechanical or thermal pain hypersensitivities. We also found that PICK1 is highly expressed in dorsal horn, where it interacts with GluR2 and PKCα. Injection of CFA into a hind paw, but not a hind paw incision, increased PKCα-mediated GluR2 phosphorylation at Ser880 and GluR2 internalization in dorsal horn. These increases were absent when spinal cord PICK1 was deficient. Given that dorsal horn PKCα-mediated GluR2 phosphorylation at Ser880 and GluR2 internalization contribute to the maintenance of CFA-induced inflammatory pain, our findings suggest that spinal PICK1 may participate in the maintenance of persistent inflammatory pain, but not in incision-induced post-operative pain, through promoting PKCα-mediated GluR2 phosphorylation and internalization in dorsal horn neurons.
Pain 10/2010; 151(1):226-34. · 5.78 Impact Factor
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ABSTRACT: Mammalian target of rapamycin (mTOR) controls protein translation and has an important role in the mechanism of pain hypersensitivity under persistent pain conditions. However, its expression and localization in pain-related regions of the nervous system is not completely understood. Here, we examined the expression and distribution of mTOR, eukaryotic initiation factor 4E-binding protein1/2 (4E-BP1/2), p70 ribosomal S6 protein kinase (p70S6K), and their phosphorylated (active) counterparts in two major pain-related regions, the dorsal root ganglion (DRG) and spinal cord dorsal horn. Reverse transcriptase-polymerase chain reaction showed that mTOR, 4E-BP1, and p70S6K mRNA are expressed in the DRG and dorsal horn. Western blot analysis further confirmed the existence of their protein products in these two regions, but expression of their phosphorylated counterparts was very low in dorsal horn and was not detected in the DRG. Immunohistochemistry revealed mTOR and p70S6K in the DRG neurons. Quantitative analysis showed that approximately 26.1% (+/- 3.2%) of DRG neurons were positive for mTOR and 19.1% (+/- 1.9%) were positive for p70S6K. Most of these neurons were small-less than 600 microm(2) in cross-sectional area-and some co-labeled with substance P or isolectin B4. Surprisingly, 4E-BP1 was observed only in the DRG satellite glial cells. In the dorsal horn, mTOR, p70S6K, and 4E-BP1 were detected in neurons, but not in astrocytes or microglia. They were distributed in the whole dorsal horn, especially in the superficial dorsal horn. Immunostaining for their phosphorylated counterparts was very low or undetectable in DRG and dorsal horn. Behavioral study showed that intrathecal mTOR inhibitor, rapamycin, did not affect acute nocicepetive transmission. The results indicate that although mTOR, p70S6K, and 4E-BP1 are highly expressed in the DRG and dorsal horn, their activate forms are very low in both regions under normal conditions. Our findings support the view that mTOR and its downstream effectors do not play a key role in acute pain.
Brain research 06/2010; 1336:46-57. · 2.46 Impact Factor
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Myron Yaster
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ABSTRACT: Acute and chronic pain management in children is increasingly characterized by either a multimodal or a preventive analgesia approach, in which smaller doses of opioid and nonopioid analgesics, such as nonsteroidal anti-inflammatory drugs, local anaesthetics, N-methyl-D-aspartate antagonists, alpha(2)-adrenergic agonists, and voltage-gated calcium channel alpha-2 delta-proteins, are combined alone and in combination with opioids to maximize pain control and minimize drug-induced adverse side effects. A multimodal approach uses nonpharmacological complementary and alternative medicine therapies too. These include distraction, guided imagery, hypnosis, relaxation techniques, biofeedback, transcutaneous electrical nerve stimulation, and acupuncture. Using the neurophysiology of pain as a blueprint, the molecular targets and strategies used in multimodal pain management are described. Finally, weight-based dosage guidelines for commonly used opioid and nonopioid analgesics are provided to facilitate therapy.
European Journal of Anaesthesiology 04/2010; 27(10):851-7. · 2.23 Impact Factor
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ABSTRACT: The influence of patient characteristics, institutional demographics, and published practice guidelines on the provision of IV opioid analgesia, particularly as delivered through a patient-controlled analgesia (PCA) delivery device, to pediatric patients is unknown.
We sent a national, web-based, descriptive survey of pediatric pain management practice to select members of the Society for Pediatric Anesthesia to assess institutional demographics, availability and implementation of IVPCA and PCA by proxy, and recalled occurrence of serious and life-threatening opioid-related side effects.
Data from respondents at 252 institutions throughout the United States were collected and analyzed. Sixty-nine percent of respondents practiced in a children's hospital or children's center within a general hospital, and 51% of institutions had a pediatric pain service. Virtually all pediatric pain services (91%) were administered by departments of anesthesiology. Pediatric pain service availability correlated with the number of pediatric beds. IVPCA was available to pediatric patients at 96% of institutions surveyed, whereas IVPCA by proxy was available at only 38%. Eleven percent of respondents reported that their hospital no longer provided IVPCA by proxy as a result of the 2004 Joint Commission on Accreditation of Hospitals Sentinel Event Warning. Instructional material concerning IVPCA was provided to patients or their families by 40% of institutions. IVPCA orders were handwritten by 55% of respondents, despite 39% having computerized provider order entry systems. Ninety percent of respondents reported using pulse oximetry monitoring when patients were administered IVPCA. Forty-two respondents recalled patients having received naloxone to counteract the cardiopulmonary side effects of opioids during the year before receipt of the survey. Eight respondents recalled patient deaths having occurred over the past 5 years in patients receiving IVPCA, IVPCA by proxy, and continuous non-IVPCA opioid infusions.
Although IVPCA was available to pediatric patients at most institutions surveyed, prescribing practices and supervision of pediatric pain management were influenced by patient characteristics, institutional demographics, and published national guidelines. Recalled life-threatening events were reported in conjunction with all modes of opioid infusion therapy. Interventions that might diminish the incidence of adverse events but are not used to their fullest extent include improved education and implementation of systems designed to minimize human error involved in the prescribing of opioids. Providing a more accurate accounting of complications would require institutions to participate in a prospective data-collecting consortium designed to track both the incidence of therapy and associated complications.
Anesthesia and analgesia 03/2010; 110(3):754-60. · 3.08 Impact Factor
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ABSTRACT: To determine if oral clonidine would reduce the duration of opioid detoxification for neonatal abstinence syndrome.
Infants with intrauterine exposure to methadone or heroin and neonatal abstinence syndrome (2 consecutive modified Finnegan scores of > or =9) were enrolled at 2 hospitals during 2002-2005 and followed until final hospital discharge. All enrolled infants (80) received oral diluted tincture of opium according to a standardized algorithm and were randomly assigned to receive oral clonidine (1 microg/kg every 4 hours) (40 infants) or placebo (40 infants). Primary outcome was duration of opioid therapy. Secondary outcomes included the amount of opium required to control symptoms, number of treatment failures, and differences in blood pressure, heart rate, and oxygen saturation.
The median length of therapy was 27% shorter in the clonidine group (11 [95% confidence interval: 8-15 days]) than in the placebo group (15 days [95% confidence interval: 12-17 days]). In the clonidine group, 7 infants required restarting opium after initial discontinuation versus none in the placebo group, with the total length of treatment/observation remaining significantly less in the clonidine group. Higher dosages of opium were required by 40% of the infants in the placebo group versus 20% in the clonidine group. Treatment failures occurred in 12.5% of the infants in the placebo group versus none in the clonidine group. Hypertension, hypotension, bradycardia, or desaturations did not occur in either group. Three infants in the clonidine group died as a result of myocarditis, sudden infant death syndrome, and homicide, all after hospital discharge and before 6 months of age.
In this randomized, double-blind trial, adding clonidine to standard opioid therapy for detoxification from in utero exposure to methadone or heroin reduced the duration of pharmacotherapy for neonatal abstinence without causing short-term adverse cardiovascular outcomes. A larger trial is indicated to determine long-term safety.
PEDIATRICS 05/2009; 123(5):e849-56. · 4.47 Impact Factor
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ABSTRACT: Peripheral nerve injury may lead to neuroadaptive changes of cellular signals in spinal cord that are thought to contribute to central mechanisms underlying neuropathic pain. Here we used a 2-DE-based proteomic technique to determine the global expression changes of synaptosome-associated proteins in spinal cord dorsal horn after unilateral fifth spinal nerve injury (SNI). The fifth lumbar dorsal horns ipsilateral to SNI or sham surgery were harvested on day 14 post-surgery, and the total soluble and synaptosomal fractions were isolated. The proteins derived from the synaptosomal fraction were resolved by 2-DE. We identified 27 proteins that displayed different expression levels after SNI, including proteins involved in transmission and modulation of noxious information, cellular metabolism, membrane receptor trafficking, oxidative stress, apoptosis, and degeneration. Six of the 27 proteins were chosen randomly and further validated in the synaptosomal fraction by Western blot analysis. Unexpectedly, Western blot analysis showed that only one protein in the total soluble fraction exhibited a significant expression change after SNI. The data indicate that peripheral nerve injury changes not only protein expression but also protein subcellular distribution in dorsal horn cells. These changes might participate in the central mechanism that underlies the maintenance of neuropathic pain.
Proteomics 03/2009; 9(5):1241-53. · 4.43 Impact Factor
