Mechanisms Of Postoperative Pain Research Articles

A Technical Approach to Anesthesia in the Case of Tonsillectomy

<div class="WordSection1"><p><strong>Background: </strong>Tonsillectomy is the most common surgical procedure performed by an ENT doctor (Throat Nose Ear) in children. This surgery can cause pain, bleeding and swelling in the injured throat. Patient may complain of pain, difficulty swallowing, eating, drinking disorders, nausea and vomiting and fall into a dehydrated state. This can reduce patient satisfaction.</p><p><strong>Discussion:</strong> Postoperative pain management of tonsillectomy is a concern both by the ENT doctor and by the anesthesiologist. The high incidence of post-tonsillectomy pain or anxiety increases the risk of secondary post-tonsillectomy bleeding. It is necessary to know the mechanism of post operative pain and the negative impact of pain.</p><p><strong>Conclusion:</strong> Doctors should give attention to reduce postoperative pain and choose a rational analgesic to overcome post operative tonsillectomy pain.</p></div>

Effect of anxiety disorder and depression in postoperative pain

Introduction: The aim of this study is to briefly present and to evaluate the elements that show whether the psychological background of the patients, particularly anxiety disorder and depression, are involved in the mechanism of postoperative pain, to examine the mechanisms involved in the intensity of pain and to report the methods used to evaluate and treat pain after a surgical procedure in this vulnerable group of patients. Methods: We performed a literature review of relevant articles, mainly published during the last decade, in MEDLINE database and 15 articles were used. Results: Clinical studies lead us to the conclusion that the intensity of postoperative pain is directly related to the levels of anxiety and to the presence of depression. Undertreatment and delay in managing acute postoperative pain can lead to the development of chronic pain syndromes with consequent negative effects in life and in the level of functionality of patients. A number of neurobiological processes could further explain the effect of psychological factors on pain, especially after surgical procedures. Conclusion: The psychological aspect of acute postoperative pain can be evaluated during the preoperative period, in order to relieve the intense negative psychological experience of pain after surgery, by using pharmacological therapy as well as psychotherapy. It is of great importance to perform psychological monitoring of patients after surgery, since it has been observed that the psychological phenotype of patients is altered during the first postoperative days. Catastrophology is involved in elevated intensity of postoperative pain, therefore the appropriate use of relevant clinical interventions would be beneficial. Psychosocial and psychophysiological evaluation is of great importance in order to detect patients at high risk and to offer individualized management and targeted preventive preoperative planning. The heterogeneity of patient population going to surgery increases the need for further studies which would evaluate appropriate therapeutic regimens, individualized for each special group of patients.

Pain management after photorefractive keratectomy.

To review current concepts regarding the mechanisms of postoperative pain after photorefractive keratectomy (PRK) and review available treatment options. Many clinical studies have established the safety and efficacy of different topical and systematic therapeutic agents and techniques for the treatment of postoperative pain after PRK, especially topical nonsteroidal anti inflammatory agents and oral nonsteroidal and narcotic medications. New therapeutic agents and techniques are continuously studied, introducing new agents and comparing teh efficacy of different regimens. Postoperative pain severity varies widely between patients, and no single strategy has been proven best for acute pain management. To date, the literature supports the use of topical agents such as nonsteroidal anti-inflammatory medications (NSAIDs) and diluted topical anesthetics in combination with oral agents such as opiates and NSAIDs for acute pain management. The use of local agents and techniques is preferred due to their less significant side effect profile. The use of systemic opiate agents is reserved for breakthrough pain.

(303) - The mast cell receptor mrgprb2 contributes to inflammatory pain via immune cell modulation

Although the mechanisms of postoperative pain are still incompletely understood, research has shed light on one potentially important immune cell. As one of the key effector cells in the inflammatory process, mast cells are an important contributor to pain pathophysiology. The role of mast cells in mediating postoperative pain is incompletely understood, although studies using mast cell stabilizers demonstrate that this immune cell is involved in contributing to nociception in animal models of postoperative pain. Thus, there is a compelling need for fundamental research aimed at understanding the mechanisms of mast cells in postoperative pain. Towards this objective, our lab has previously published data identifying a novel mast cell specific receptor, Mas-related G-protein-coupled receptor B2 (MRGB2) and its human orthologue, MRGX2, in non-allergenic activation of mast cells. To evaluate the role of MRGB2 in postoperative pain we utilized a hindpaw incision model. After baselines were measured, mice were anesthetized and a 5-mm incision beginning 2 mm from the proximal edge of the right heel was made. Curved forceps elevated the underlying muscle. A mattress suture of 8–0 nylon on a TG175-8 needle were then used to close the incision. Antibiotic ointment (Bacitracin Zinc Ointment) was then applied. Male C57bl/6 wild-type (WT) or MRGB2KO (n = 6/group) were tested 24 h after incision surgery. Behavioral testing was done utilizing the radiant heat test and Von Frey filaments. At 24 hours post-surgery we saw significant reduction in both mechanical and thermal allodynia in MRGB2 KO mice but not WT, indicating that mast cells contribute to postoperative allodynia via MRGB2. Further study of the mechanisms underlying the role of this receptor in mediating incision induced pain may provide potential strategies for the development of novel analgesics to treat debilitating postoperative pain.

Modern Postoperative Pain to the Treatment Approaches in Oncogynecology

Effective postoperative analgesia is one of the successful rehabilitation conditions. Mechanisms of postoperative pain have been being studied by now, and more new analgesics and anesthesia techniques are introduced. The range of surgical interventions in oncogynecology is wide: from minimally invasive laparoscopic operations to radical hysterectomies involving healthy tissues and removal of regional lymph nodes. Postoperative pain following radical hysterectomy with an intensity of more than 6 on visual analogue scale (VAS) requires multimodal pain therapy. Inadequate pain management leads to its transformation to a chronic condition, a neuropathic pain, associated with not fully reversible changes in patient’s brain. This article is based on the results of a systematic literature review developed by PROSPECT (cooperation of surgeons and anaesthesiologists in developing guidelines for specific procedures and manipulations). It deals with optimization of pain management highlighting new post-operative care principles.

Mechanisms of postoperative pain

Mechanisms of postoperative pain

(296) MRGB2 contributes to mechanical and thermal allodynia in an animal model of postoperative pain

Although the mechanisms of postoperative pain are still incompletely understood, research has shed light on one potentially important immune cell. As one of the key effector cells in the inflammatory process, mast cells are an important contributor to pain pathophysiology. The role of mast cells in mediating postoperative pain is incompletely understood, although studies using mast cell stabilizers demonstrate that this immune cell is involved in contributing to nociception in animal models of postoperative pain. Thus, there is a compelling need for fundamental research aimed at understanding the mechanisms of mast cells in postoperative pain. Towards this objective, our lab has previously published data identifying a novel mast cell specific receptor, Mas-related G-protein-coupled receptor B2 (MRGB2) and its human orthologue, MRGX2, in non-allergenic activation of mast cells.1 To evaluate the role of MRGB2 in postoperative pain we utilized a hindpaw incision model. After baselines were measured, mice were anesthetized and a 5-mm incision beginning 2 mm from the proximal edge of the right heel was made. Curved forceps elevated the underlying muscle. A mattress suture of 8–0 nylon on a TG175-8 needle were then used to close the incision. Antibiotic ointment (Bacitracin Zinc Ointment) was then applied. Male C57bl/6 wild-type (WT) or MRGB2KO (n=6/group) were tested 24 h after incision surgery. Behavioral testing was done utilizing the radiant heat test and Von Frey filaments. At 24 hours post-surgery we saw significant reduction in both mechanical and thermal allodynia in MRGB2 KO mice but not WT, indicating that mast cells contribute to postoperative allodynia via MRGB2. Further study of the mechanisms underlying the role of this receptor in mediating incision induced pain may provide potential strategies for the development of novel analgesics to treat debilitating postoperative pain. (1. McNeil B, et al. Nature 2015.)

New progress of orthopaedic postoperative multimodal analgesia

A single drug or a method may not achieve the best result for the management post-operative pain, so multimodal analgesia is proposed as a new analgesic concept in recent years. This article describes the mechanism of postoperative pain, some of the factors affecting postoperative pain and the importance of the treatment of postoperative pain after surgery. It also introduces a variety of analgesic drugs and methods commonly used as multimodal analgesia in postoperative pain treatment in orthopaedic. Foreground of the research is prospected as well. Key words: Postoperative pain; Multimodal analgesia; Methods

Mechanisms of postoperative pain

Mechanisms of postoperative pain

Changes in Response Properties and Receptive Fields of Spinal Dorsal Horn Neurons in Rats after Surgical Incision in Hairy Skin

Mechanical hyperalgesia and allodynia associated with chemical irritant application are mediated by spinal high-threshold (HT) as well as wide-dynamic-range neurons as a result of "central sensitization." Because the pathophysiology of pain is thought to differ depending on the type of injury and may vary between hairy and glabrous skin, the authors examined changes in properties of spinal dorsal horn neurons after surgical incisions in hairy skin of rats to obtain insights into the mechanisms of postoperative pain. Withdrawal responses to punctate mechanical stimulation and gentle brushing were measured in awake rats in an area adjacent to the injured site (primary area) and in an area 2 cm from the injured site (secondary area) after 1-cm longitudinal incisions through the hairy skin, fascia, and muscle had been made in the hindquarters. In a separate study, responses of spinal wide-dynamic-range, HT, and low-threshold neurons to nonnoxious and noxious stimuli were recorded before and after similar incisions had been made in the centers of their receptive fields. Effects of spinal application of the gamma-aminobutyric acid A receptor antagonist bicuculline (15 microg) on responses of HT neurons were then studied. Awake rats showed primary and secondary hyperalgesia to punctate mechanical stimulation 30 min after the incision and thereafter for 4 days and 1 day, respectively. Mechanical allodynia associated with brush stimulation was only seen in the primary area 30 min after the incision and thereafter for 1 day. The incision resulted in increases in activity of wide-dynamic-range neurons (receptive field sizes and responses to both innocuous and noxious stimuli). HT neurons did not respond to innocuous stimulation and showed very small increases or no changes in receptive field size and responses to noxious stimuli after the incision. However, the majority of HT neurons began to respond to innocuous stimuli after application of bicuculline (15 microg/50 microl) to the spinal cord. The results suggest that wide-dynamic-range neurons are responsible for behavioral hyperexcitability after surgical incision but that HT neurons are not involved in the hyperexcitability, despite the fact that HT neurons are capable of responding to innocuous stimuli by reversal of gamma-aminobutyric acid-mediated inhibition.

Effects of Capsaicin Application to Peripheral Nerves in a Rat Model for Human Postoperative Pain

Background: The interest in management of postoperative pain has increased with the development of medicine. The mechanism of postoperative pain should be understood first. Capsaicin has been proven to be a powerful agent acting selectively on nociceptive afferent fibers. This study was focused on how the perineural treatment of capsaicin affects pain after an incision in the rat model. Methods: Capsaicin was applied directly to sciatic nerve branches, on the are tibial, sural, and saphenous nerves. Pain behaviors to von Frey filaments, blunt probe stimulation, resting pain, and heat were evaluated on the incised feet. The grade of wound healing was assessed according to clinical findings of the wound 3 days postoperatively. Results: Capsaicin applied directly onto nerves elevated withdrawal latency to heat during the study. There were statistically significant increases of withdrawal latencies in the capsaicin group compared with the vehicle group. Capsaicin produced agreater increase of the withdrawal threshold to von Frey than the vehicle 2 days after the incision. Resting pain scores were lower in capsaicin - treated rats than in the vehicle group for 2 days. The grade of wound healing was poor in capsaicin - treated rats. Conclusions: The perineural application of capsaicin appears to affect the pathway of transmission of postoperative pain. Current results suggest that capsaicin has a strong analgesic effect on thermal hyperalgesia and attenuates mechanical hyperalgesia by an incision. Capsaicin sensitive nerves could be involved in wound healing.