Induction of suppressor of cytokine signaling 3 via HSF-1-HSP70-TLR4 axis attenuates neuroinflammation and ameliorates postoperative pain

Postoperative pain is a common form of acute pain that, if not managed effectively, can become chronic pain. Evidence has shown that glia, especially microglia, mediate neuroinflammation, which plays a vital role in pain sensitization. Moreover, toll-like receptor 4 (TLR4), the tumor necrosis factor receptor (TNF-R), the interleukin-1 receptor (IL-1R), and the interleukin-6 receptor (IL-6R) have been considered key components in central pain sensitization and neuroinflammation. Therefore, we hypothesized that activation of the body's endogenous "immune brakes" will inhibit these receptors and achieve inflammation tolerance as well as relieve postoperative pain. After searching for potential candidates to serve as this immune brake, we identified and focused on the suppressor of cytokine signaling 3 (SOCS3) gene. To regulate SOCS3 expression, we used paeoniflorin to induce heat shock protein 70 (HSP70)/TLR4 signaling. We found that paeoniflorin significantly induced SOCS3 expression both in vitro and in vivo and promoted the efflux of HSP70 from the cytoplasm to the extracellular environment. Furthermore, paeoniflorin markedly attenuated incision-induced mechanical allodynia, and this effect was abolished by small interfering RNAs targeting SOCS3. These findings demonstrated an effective and safe strategy to alleviate postoperative pain.

[Effect of Subcutaneous Injection of Lidocaine in Zusanli (ST 36) and Jiaji (EX-B 2) Regions on Immune Function in Patients Undergoing Laparoscopic Cholecystectomy]

OBJECTIVE

To observe the effect of acupoint injection of Lidocaine on serum IL-1β, TNF-α and T-lymphocyte subset activities in patients undergoing laparoscopic cholecystectomy (LC), so as to reveal its mechanisms underlying relieving postoperative pain and potentiating rehabilitation.

METHODS

Eighty patients scheduled for elective LC surgery (grade I or II, according to American Standards of Association, ASA) were randomly divided into four groups, namely intravenous analgesia (IVA) , right forearm-injection (forearm-), Jiaji (EX-B 2, Thorax 8)-injection (EX-B 2-1), and Zusanli-injection (ST 36-1), with 20 patients in each group. The conventional anesthetic induction and maintenance with Penehyclidine Hydrochloride, Midazolam, Sulfentanil, Propofol, Atracurium Besilate, and Remifentanil were same in all the 4 groups. For patients of the forearm-I, EX-B 2-I and ST 36-1 groups, 5% Lidocaine was injected into the subcutaneous layer of the anterior side of right forearm near the elbow, EX-B 2 and ST 36 regions, respectively. Analgesia pump (filled with Sulfentanil, Ramosetron + normal saline) was connected af- ter the tracheal extubation. The visual analog scale (VAS) was used to assess the patient's pain reaction after tracheal extubation (T 1), and 6 h (T 2), 24 h (T 3) and 48.h (T 4) after surgery. The times of RCA pressing and the total dose of Sufentanil in the process of postoperative analgesia were recorded as well. The contents of serum IL-1β and TNF-α were analyzed by ELISA, and the counts of CD4+ and CD+ T cells were detected by flow cytometry.

RESULTS

Compared with T 1 in the same one group, the VAS scores at time-points of T 2, T 3 and T 4 after surgery of all the IVA, forearm-1, ST 36- and EX-B 2- groups were reduced significaantly (P < 0.05). The times of PCA-pump pressing and the doses of the administrated Sufentanil were considerably lower in the ST 36-1 and EX-B 2-I groups than in the IVA and forearm-I groups (P < 0.05). In comparison with pre-anesthesia in the same one group, serum TNF-α and IL-1β contents at T 1 were remarkably increased, while the ratios of CD⁴⁺/CD⁸⁺ at T 4 in the 4 groups were evidently down-regulated (P < 0.05). The contents of serum TNF-α and IL-1β at T 3 and T 4 were obviously lower in both ST 36-1 and EX-B 2-1 groups than in the IVA and forearm-I groups (P < 0.05). No significant differences were found among the 4 groups in the VAS scores at the 4 time-points, in the serum TNF-α and IL-1β contents at T 0 and T 1, in the counts of CD⁴⁺ and CD⁸⁺ T cells and ratios of CD⁴⁺/CD⁸⁺ at T 0, T 3 and T 4, and between the ST 36-1 and EX-B 2-groups in all the 8 indexes (P > 0.05).

CONCLUSION

Acupoint injection of Lidocaine is effective in relieving pain in LC patients, which is demonstrated by reducing VAS score, PCA pump pressing times, and administrated Sufentanil dose, and may be associated with its effects in down-regulating serum TNF-α and IL-1β contents.

[Effects of epidural anesthesia on stress-induced immune supression during major corrective spine surgery]

STUDY DESIGN

A prospective, randomized study wias performed to compare two anesthetic methods.

OBJECTIVE

To evaluate the effect of epidural analgesia on postoperative pain, endocrine- metabolic and inflammatory stress response and cellular inmmune responses during major corrective spine surgetry.

METHODS

The study included 350 patients aged 15 to 65 who were randomly allocated to two equal groups. Group I (n=205) had continuous epidural analgesia (E4) and sevoflurane anesthesia during surgety and continuous epidural analgesia with ropivacaine and fentanil after surgery; Group 2 (n= 145) had general anesthesia with sevoflurane and fentanil and systemic administration of opioids after surgery. Patient pain, PONV syndrome, mobility, and satisfaction were measured after surgery along with plasma levels ofcortisol, ghmcose, interleukins IL-1β, IL-6, and IL-10 during and after surgemy C-reactive protein (CRP), and cell-surface receptor expression of immune cells (cluster of differentiation) HLA-DR+/CD3-, HLA-DR+/CD3+, HILA-DR, CD3, CD4, CD8, CD16, CD19 CD16/56+, and CD16/56+/CD3+) were measured perioperatively.

RESULTS

In group 1, there were significantly less pain, less nausea, earlier mobility, and higher satisfaction than those in group 2. Group I has also demonstrated significantly less plasma levels of glucose, cortisol, CRP, IL-lβ, IL-6, IL-10 at various stages. The ratio of CD4/CD8 (p=0.001) and B cells (p=0.01) have increased by postoperative day 3 in group 1. NK-cells (CD16/56+) have decreased significantly by day 3 after surgery (p=0.001) compared to the group 2. T-lymphocytes, (CD3) have decreased in all patients, but they were significantly lower in patients receiving opioids, compared wiith EA.

CONCLUSIONS

Polerfulr afferent stimulation in major corrective spine surgery accompanied by immunosuppression for at least a wieek after surgery. EA reduces the surgical stress response, prevents postoperative lymphocyte apoptosis and thus, increases stress and infectious resistance.

[ASSESSMENT OF POSTOPERATIVE PAIN SYNDROME AT SINGLE-PORT TRANSUMBILICAL LAPAROSCOPIC CHOLECYSTECTOMY COMPARED TO TRADITIONAL LAPAROSCOPIC CHOLECYSTECTOMY]

The article analyzes the dynamics of postoperative pain at single-port transumbilical laparoscopic cholecystectomy compared to traditional laparoscopic cholecystectomy. It is shown that the intensity of pain in patients who have undergone laparoscopic procedures through a single transumbilical access was significantly less than in patients with traditional laparoscopic intervention. Furthermore, the use of a single-port transumbilical laparoscopic cholecystectomy accompanied by a smaller increase in the concentration of proinflammatory cytokines compared with patients who had laparoscopic procedures through four trocar accesses.

Effect of thoracic epidural analgesia on pro-inflammatory cytokines in patients subjected to protective lung ventilation during Ivor Lewis esophagectomy

BACKGROUND

Thoracic epidural analgesia (TEA) has a well-known effect on neurohormonal response. Attenuation of stress response by post-operative epidural analgesia has shown beneficial effects such as lower pain scores and less immunological alterations.

OBJECTIVES

Investigation of the combined effects of TEA and protective lung ventilation on pro-inflammatory cytokines and patients' outcome after Ivor Lewis esophagectomy.

STUDY DESIGN

A randomized controlled study.

SETTING

Academic medical center.

METHODS

Thirty patients of the American Society of Anesthesiologists (ASA) I and II were randomly allocated into 2 groups: G1 (n = 15) patients received general anesthesia and were mechanically ventilated with 9 mL/kg during 2 lung ventilations, reduced to 5 mL/kg and 5cm H2O positive end expiratory pressure (PEEP) during one lung ventilation (OLV) or GII) (n = 15) patients received TEA and the same general anesthesia and mechanical ventilation used in G1. Assessment parameters included hemodynamics, pain severity, total analgesic consumption, and measurement of interleukins (IL) (IL-6 and IL-8) at baseline time after anesthetic induction (TBaseline,); at the end of the abdominal stage of the operation (TAbdo,); 15 minutes after initiation and at the end of OLV (TOLV 15) and (TOLV End) respectively; one and 20 hours after the end of the surgical procedure (TPostop1 and TPostop20), respectively, and patient's outcome also recorded.

RESULTS

There was a significant reduction in mean arterial blood pressure (MAP) and pulse rate in GII during the intraoperative period, at Tabdo, TOLV15, and TOLV End (P < 0.05). The mean of systolic blood pressure (SBP) values were significantly lower in GII over all 3 post-operative days (P = 0.001), and the mean diastolic blood pressure (DBP) showed a significant reduction in GII for 16 hours post-operatively (P = 0.001). The mean of heart rate values showed a significant reduction in GII over all 3 post-operative days in comparison to GI (P = 0.001). The mean resting and dynamic VAS scores were significantly reduced in GII at all time periods studied in comparison to G1 (P = 0.001). The daily PCA morphine consumption was markedly decreased in GII compared to GI in the first 3 days post-operatively (P = 0.001). There were significant reductions in blood level of IL-6 and IL-8 in GII compared to G1 over the entire study period (P < 0.05). There were no significant differences in post-operative adverse effects between the 2 groups (P > 0.05). The duration of stay in PACU was significantly decreased in GII (10 ± 2 days) compared to GI (15 ± 3 days) (P = 0.001).

LIMITATIONS

This study is limited by its sample size.

CONCLUSION

Our study concluded that TEA reduced the systemic pro-inflammatory response and provided optimal post-operative pain relief. Although there were no significant differences in adverse events, there was a trend towards improved outcome. Further clinical studies with larger numbers of patients are required.

Th17 cell frequency and IL-17 concentration correlate with pre- and postoperative pain sensation in patients with intervertebral disk degeneration

Numerous studies have revealed the presence of T helper 17 (Th17) cells in pathologic intervertebral disk (IVD) tissues and the contribution of Th17-associated cytokines to the development of this disease. However, the pre- and postoperative changes in the proportion of Th17 cells and the concentration of IL-17 in the peripheral blood of patients with IVD degeneration are not clear. The levels of Th17 frequency and the interleukin-17 (IL-17) concentration in peripheral blood from patients and volunteers were examined by flow cytometry and by enzyme-linked immunosorbent assay (ELISA), respectively. The clinical results were evaluated using the visual analogue scale (VAS). These results were subjected to a correlation analysis. Compared with the normal controls, the proportion of Th17 cells and the concentration of IL-17 were significantly increased preoperatively in patients with IVD degeneration. Postoperatively, the levels of Th17 cells and the expression of IL-17 were dramatically decreased. The correlation analysis of the VAS pain scores, Th17 cell frequency, and IL-17 concentration, including the pre- and postoperative levels and the changes induced by the surgery, revealed a positive correlation. The authors' results explain the contribution of Th17 cells and IL-17 to the pain sensation experienced by patients with IVD degeneration. These 2 factors may be good indicators for the evaluation of the surgical outcome of patients with lumbar disk herniation.

[Effect of early multimodal rehabilitation on postoperative recovery after abdominal hysterectomy]

Purpose of the study was to evaluate the impact of the use of enhanced recovery after surgery for the postoperative period, and the inflammatory response after hysterectomy.

INTRODUCTION

Methods Prospectively, 50 patients ASA 1-2 aged 42-72 years were randomized into two groups: the ERAS group (n = 25) and the control group (CG) with traditional perioperative management (n = 25). combined spinal and epidural anesthesia technique was used in all patients. Patient-controlled epidural analgesia in the ERAS group and multimodal analgesia with combination of paracetamol, tramadol and ketoprofen in the control group were used postoperatively. We measured plasma concentrations of interleukin-6 (IL-6), interleuki-nIL-1beta (IL-1beta) and C-reactive protein (CRP) preoperatively and at 24 hours and 7 days after surgery. Data were analyzed by Mann-Whitney U test and presented as median (25th- 75th percentiles).

RESULTS

There was no statistically significant differences in the IL-6 and IL-1beta concentrations throughout the study. At 6 and 24 hours the pain severity of according to VAS was higher in the control group at rest and on coughing during all study stages. We found no correlation between the level of pain and plasma concentrations of IL-1beta and IL-6. The plasma concentration of CRP in the control group was higher at 24 hours and at 7 days after surgery: (P < 0.01). Level of CRP in the control group tended to increase during the observation period.

CONCLUSIONS

In our study, the serum concentration of IL-6 and IL-1beta did not depend on the method of postoperative pain management. Using the ERAS protocol reduced postoperative plasma concentration of CRP. The increased level of CRP in the control group may be related with autoimmune reaction in wound due to delayed mobilization of patients.

Antinociceptive effect of Mirabilis jalapa on acute and chronic pain models in mice

ETHNOPHARMACOLOGICAL RELEVANCE

The infusion or decoction of Mirabilis jalapa leaves is used in traditional medicine in Brazil to treat inflammatory and painful diseases. Thus, the present study was designed to investigate whether the leaf ethyl acetate (Eta) fraction from Mirabilis jalapa exhibits antinociceptive effect in clinically relevant pain models in mice. Furthermore, we have investigated the role of cholinergic system in the antinociceptive action produced by Eta in mice.

MATERIALS AND METHODS

The effect of Eta administered orally (10mg/kg, p.o.) in mice was verified on the painful hypersensitivity (mechanical allodynia) in models of chronic inflammation (subcutaneous injection of complete Freund's Adjuvant-CFA in the plantar surface of the right hind paw), postoperative (paw surgical incision) and neuropathic (partial sciatic nerve ligation) pain. In the chronic inflammation model, we further verified the effect of Eta treatment on paw edema and interleukin-1β (IL-1β) levels. We also investigated the role of muscarinic and nicotinic receptors in the antiallodynic action produced by Eta as well as the possible action of Eta on in vitro and ex vivo acetylcholinesterase activity in CFA treated animals. Furthermore, we verified the effect of Eta treatment on the parameters of liver and kidney lesion (level of urea, and activity of aspartate aminotransferase and alanine aminotransferase).

RESULTS

Eta produced marked reduction in the allodynia caused by CFA, surgical incision and partial sciatic nerve ligation. However, Eta did not alter the paw edema or the increase of IL-1β levels produced by CFA. The antinociceptive effect of Eta was reversed by the pre-treatment of animals with the antagonists of muscarinic (atropine, 5mg/kg, s.c) or nicotinic (mecamylamine, 0.001mg/kg, s.c.) receptors. Eta did not alter in vitro acetylcholinesterase activity in blood or spinal cord samples, but it reversed the increase in the acetylcholinesterase activity observed in the spinal cord samples from mice injected with CFA. Moreover, Eta did not alter the indicators of liver or kidney lesion.

CONCLUSIONS

Based on its use in traditional medicine, the results of the present study confirmed the antinociceptive properties of Eta in clinically relevant pain models. Also its effect on the CFA-induced chronic inflammation seems to be related to acetylcholinesterase inhibition and cholinergic system.

Involvement of mast cells in a mouse model of postoperative pain

Recent studies have indicated that nearly half of all surgical patients still have inadequate pain relief; therefore, it is becoming increasingly more important to understand the mechanisms involved in postoperative pain in order to be better treated. Previous studies have shown that incisions can cause mast cell degranulation. Thus, the aim of this study was to investigate the involvement of mast cells in a model of postoperative pain in mice. The depletion of mast cell mediators produced by pre-treatment with compound 48/80 (intraplantar (i.pl.)) widely (98 ± 23% of inhibition) and extensively (up to 96 h) prevented postoperative nociception and reduced histamine and serotonin levels (88 ± 4% and 68 ± 10%, respectively) in operated tissue. Furthermore, plantar surgery produced immense mast cell degranulation, as assessed by histology and confirmed by the increased levels of serotonin (three-fold higher) and histamine (fifteen-fold higher) in the perfused tissue, 1h after surgery. Accordingly, pre-treatment with the mast cell membrane stabilizer cromoglycate (200 μg/paw, i.pl.) prevented mechanical allodynia (inhibition of 96 ± 21%) and an increase in histamine (44 ± 10% of inhibition) and serotonin (73 ± 5% of inhibition) levels induced by plantar surgery. Finally, local treatment with H(1) (promethazine, 100 μg/paw, i.pl.), 5-HT(3) (ondansetron, 10 μg/paw, i.pl.) or 5-HT(2A) (ketanserin, 5 μg/paw, i.pl.) receptor antagonists partially decreased postoperative nociception in mice, but when co-administered together it completely reversed the mechanical allodynia in operated mice. Thus, mast cell activation mechanisms are interesting targets for the development of novel therapies to treat postoperative pain.

Cross-talk between NKT and regulatory T cells (Tregs) in modulation of immune response in patients with colorectal cancer following different pain management techniques

Natural killer T (NKT) and regulatory T cells (Tregs) play an important role in innate immune response. Natural killer (NK) and NKT cells are indispensable factors in the body's ongoing defense against tumor development, as well as viral infection. NKT cells are a subset of T cells that shares properties of natural killer cells and conventional T cells. They are involved in innate immune responses, tumor rejection, post transplantation immunotherapy, immune surveillance and control of autoimmune diseases. They may also play both protective and harmful roles in the progression of certain autoimmune diseases, such as diabetes, lupus, atherosclerosis, and allergen-induced asthma. Immune surveillance involves the process whereby precancerous and malignant cells are recognized by the host immune system as damaged and are consequently targeted for elimination. The pharmacological management of postoperative pain in patients with malignancies uses very different techniques whose possible cytotoxic functions we still known very poor. The present study compared effects of two different postoperative pain management techniques in patients undergoing colorectal cancer surgery on the innate immunity. Our data indicate that the patients with colorectal cancer have significantly increased the percentage of Tregs and NKT cells. The values were statistically higher during epidural analgesia in comparison with intravenous analgesia, indicating that epidural pain management technique ameliorate the immune suppression after surgery.

[Effects of laparoscopic cholecystectomy under different anesthetic methods on T-lymphocyte immune function and postoperative analgesia]

OBJECTIVE

To compare the differences in the effect of laparoscopic cholecystectomy (LC) with different anesthetic methods on T-lymphocyte immune function and postoperative analgesia as well as validate the specificity of meridian points.

METHODS

Ninety cases of LC were randomized into three groups, named group A (compound general anesthesia group with meridian points involved), group B (compound general anesthesia group with placebo points involved) and group C (general anesthesia group). In group A, electroacupuncture was applied at first for 15 to 30 min to bilateral Hegu (LI 4), Neiguan (PC 6), Zusanli (ST 36), Yanglingquan (GB 34) and Quchi (LI 11). Afterwards, the general anesthesia was conducted and electric stimulation lasted till the end of operation. In group B, the points adopted were the midpoints between the meridians in which the acupoints were selected in group A and the adjacent meridians on the lateral side, at the level of selected meridian points correspondingly. The method and time of electroacupuncture were same as those in group A. In group C, the general anesthesia was adopted simply. The changes of T-lymphocyte subgroup were detected before anesthesia, in 2 h, 1 day and 3 days after operation separately; and the dose of narcotic in operation as well as the dose of analgesia pumper in 4 h, 6 h, 8 h, 24 h and 44 h after operation separately.

RESULTS

(1) In comparison between the result 2 h after operation and that before operation, the levels of CD3+, CD4+ and CD8+ in all of three groups were lower than those before operation. Except that the change in CD4+ in group A did not present significant statistical difference as compared with that before operation (P > 0.05), all of the other differences in T-lymphocyte subgroup indicated statistical significance (all P < 0.05). The ratio of CD4+/CD8+ in three groups was higher than that before operation, but the difference in group A was significant statistically (P < 0.05). In 3 days after operation, the levels of CD3+, CD4+ and CD4+/CD8+ were all higher than those before operation, indicating significant statistical differences (all P < 0.05) except CD4+/CD8+ in group B (P > 0.05). (2) In group A, during operation, the dose of narcotic reduced apparently (P < 0.05). (3) Separately, in 4, 6 and 8 h after operation, the dose of analgesia pumper reduced significantly in group A (all P < 0.05).

CONCLUSION

Compound general anesthesia with meridian points involved can increase pain threshold of human body, reduce the dose of narcotic during operation, alleviate the suppression in body immune regulation due to stress reaction of general anesthesia and operation, prolong the time-effect of postoperative analgesia and explain the specificity of meridian points.

[Immunity and cytokine status after surgeries on the large intestine]

The aim of our study was to examine the effect of individual schemes of multimodal analgesia on indicators of immunity and inflammation markers after operations on the colon. Patients of group 1 (n=15) received paracetamol, lornoxicam and epidural ropivacaine, 2nd group of patients (n=15)-paracetamol, epidural ropivacaine and tramadol. Comparison group (n=10) patients underwent patient controlled analgesia by promedol. Before surgery, 1st and 3rd days after surgery we examined the contents of cytokines in plasma: interleukin 12p70, interleukin 10, interleukin 6, and TNF. Before surgery and at 5-7 days after surgery indicators of cellular, fagocytal and humoral immunity were monitored. Before surgery patients with colorectal cancer revealed changes in the indices of different components of immunity, as well as an increase in pro-and anti-inflammatory cytokines compared with healthy donors. Multimodal analgesia in patients after operations on the colon is not accompanied by changes in plasma concentrations of cytokines and parameters of immune status in comparison with monoanalgesia by promedol.

Effects of anesthetics and analgesics on natural killer cell activity

Surgical excision of cancerous tumors and the human stress response can lead to metastasis of tumor cells. Furthermore, the medications used during the perioperative period (eg, opioids and anesthetic agents) have been shown to inhibit or suppress natural killer (NK) cell activity, one of the body's main defenses against spread of cancer. There are currently no anesthetic regimens that have been shown to completely reverse surgical stress-induced suppression of NK cell activity. However, there may be anesthetic techniques that attenuate surgical suppression of NK cell activity. This article reviews the effects of various anesthetics and analgesics on NK cell activity and suggests techniques to attenuate the suppressive effects of these compounds.

Preoperative clonidine or levobupivacaine--effect on systemic inflammatory stress response

With perioperative pain control it is possible to supervise immune system, release of inflammation mediators, and influence on treatment outcome. Use of analgetics before the pain stimulus (preventive analgesia) obstruct development of neuroplastic changes in central nervous system, and reduces pain. Investigation hypothesis was that preoperative epidural clonidine is more efficient in blockade of systemic inflammatory stress response comparing to levobupivacaine. Patients were allocated to three groups, according to preoperative epidural use of clonidine, levobupivacaine or saline (control group). Before operation, 1 h after the beginning, 1 h, 6 h, 12 h and 24 h after the operation following parameters were analyzed: interleukine-6, C-reactive protein and leukocyte count. There were no significant differences between groups in age, gender, body mass index and operation time. In preoperative clonidine group, we found significant reduction in interleukine-6 levels throughout investigation time, compared to preoperative levobupivacaine group and control group. Also, C-reactive protein was significantly lower at the end of investigation, compared to other two groups. Leukocyte count was lower, and within the normal range in all investigation times only in preoperative clonidine group. We demonstrated significant difference that support importance of clonidine central effect on pain pathways and systemic inflammatory blockade.

Morphine reduces local cytokine expression and neutrophil infiltration after incision

Background

Inflammation and nociceptive sensitization are hallmarks of tissue surrounding surgical incisions. Recent studies demonstrate that several cytokines may participate in the enhancement of nociception near these wounds. Since opioids like morphine interact with neutrophils and other immunocytes, it is possible that morphine exerts some of its antinociceptive action after surgical incision by altering the vigor of the inflammatory response. On the other hand, keratinocytes also express opioid receptors and have the capacity to produce cytokines after injury. Our studies were directed towards determining if opioids alter cytokine production near incisions and to identify cell populations responsible for producing these cytokines.

Results

A murine incisional model was used to measure the effects of acute morphine administration (0.1–10 mg/kg) on nociceptive thresholds, neutrophil infiltration and cytokine production in hind paw skin 30 minutes and 2 hours after incision. Incised hind paws displayed profound allodynia which was reduced by morphine (0.1–10 mg/kg) in the 2 hours following incision. Skin samples harvested from these mice showed enhanced levels of 5 cytokines: IL-1β, IL-6, tumor necrosis factor alpha (TNFα), granulocyte colony stimulating factor (G-CSF) and keratinocyte-derived cytokine (KC). Morphine reduced these incision-stimulated levels. Separate analyses measuring myeloperoxidase (MPO) and using immunohistochemistry demonstrated that morphine dose-dependently reduced the infiltration of neutrophils into the peri-incisional tissue. The dose of morphine required for reduction of cytokine accumulation, however, was below that required for inhibition of peri-incisional neutrophil infiltration. Additional immunohistochemical studies revealed wound edge keratinocytes as being an important source of cytokines in the acute phase after incision.

Conclusion

Acute morphine administration of doses as low as 0.1 mg/kg reduces peri-incisional cytokine expression. A reduction in neutrophil infiltration does not provide a complete explanation for this effect, and keratinocytes may be responsible for some incision area cytokine production. These studies suggest that morphine may alter the inflammatory milieu of incisional wounds, but these alterations do not likely contribute significantly to analgesia in the acute setting.

Influence of pain treatment by epidural fentanyl and bupivacaine on homing of opioid-containing leukocytes to surgical wounds

Endogenous opioids released from leukocytes extravasating into injured tissue can interact with peripheral opioid receptors to inhibit nociception. Animal studies have shown that the homing of opioid-producing leukocytes to the injured site is modulated by spinal blockade of noxious input. This study investigated whether epidural analgesia (EDA) influences the migration of beta-endorphin (END) and/or met-enkephalin (ENK)-containing leukocytes into the subcutaneous wound tissue of patients undergoing abdominal surgery. In part I patients received general anesthesia combined either with intra- and postoperative EDA (with bupivacaine and fentanyl) or with postoperative patient controlled intravenous analgesia (PCIA; with the opioid piritramide). In part II patients received general anesthesia combined with either epidural fentanyl or bupivacaine which was continued postoperatively. Samples of cutanous and subcutanous tissue were taken from the wound site at the beginning, at the end and at various times after surgery, and were examined by immunohistochemistry for the presence of END and ENK. We found that (i) epidural bupivacaine, fentanyl and PCIA provided similar and clinically acceptable postoperative pain relief; (ii) compared to PCIA, epidural bupivacaine or fentanyl did not change the gross inflammatory reaction within the surgical wound; (iii) opioid-containing leukocytes were almost absent in normal subcutaneous tissue but migrated to the inflamed wound tissue in ascending numbers within a few hours, reaching a peak at about 24 h after surgery; (iv) compared to PCIA, EDA resulted in significantly decreased homing of END-containing leukocytes to the injured site at 24 h after surgery; and (v) the magnitude of this decrease was similar regardless of the epidural medication. These findings suggest that nociceptive but not sympathetic neurons are primarily involved in the attraction of opioid-containing leukocytes during early stages of inflammation.

[Immunological aspects of postoperative analgesia after abdominal hysterectomy]

BACKGROUND

Prostaglandins modulate cytokine release though increases in cAMP, regulating interleukin-6 and interleukin-10. Ketoprofen inhibits cyclo-oxygenase activity and hence prostaglandin production.

AIM

We hypothesized that ketoprofen would affect release of IL-6 and IL-10 and modulate the immune response.

METHOD

We have evaluated 40 women, divided into four groups by the model of postoperative pain treatment: control group (only opioid) and experimental group (combination of i.v. ketoprofen and opioid). Serum IL-6 and IL-10 were measured before surgery, 24 and 72 hours after skin incision. Due to days in hospital we detected temperature and severe complications.

RESULTS

IL-6 increased at 24h and normalized at 72h. In contrast IL-10 did not change significantly.

CONCLUSION

The two models of postoperative analgesia have both modulated immune response after abdominal hysterectomy in same way.

Acetaminophen selectively suppresses peripheral prostaglandin E2 release and increases COX-2 gene expression in a clinical model of acute inflammation

Acetaminophen is widely used for pain management as an alternative to NSAIDs and selective COX-2 inhibitors, but its action at a molecular level is still unclear. We evaluated acetaminophen's effect on PG release and the expression patterns of genes related to PG production in a clinical model of tissue injury and acute inflammation. Subjects (119 outpatients) received either 1000 mg acetaminophen, 50 mg rofecoxib (a selective COX-2 inhibitor), 30 mg ketorolac (a dual COX-1/COX-2 inhibitor), or placebo before the surgical removal of two impacted mandibular third molars. Microdialysis was used to collect inflammatory transudate from the surgical site for measurement of PGE2 and TXB2 levels at the site of injury. Biopsies were collected to investigate the expression patterns of genes related to PG production at baseline prior to surgery and at 3 or 24 h following surgery. PGE2 release was suppressed by ketorolac, rofecoxib and acetaminophen compared to placebo at 3 h coincident with increased COX-2 gene expression in biopsies collected from the surgical site. TXB2 release was suppressed only by ketorolac. COX-2 gene expression remained elevated at 24 h with continued ketorolac and acetaminophen treatment. COX-1 gene expression was significantly down-regulated at 24 h by ketorolac, rofecoxib and acetaminophen. Acetaminophen suppression of PGE2 without inhibiting TXB2 release, when COX-2 gene expression is up-regulated, suggests that acetaminophen is a selective COX-2 inhibitor in vivo. The up-regulation of COX-2 gene and down-regulation of COX-1 gene expression suggests that acetaminophen may result in changes in COX-derived prostanoids with repeated doses.

Comparison of postoperative pain management techniques on endocrine response to surgery: a randomised controlled trial

The present study compared three postoperative pain management techniques in patients undergoing lower abdominal surgery: intermittent opiate regimen (IOR), patient-controlled analgesia (PCA), and patient-controlled epidural analgesia (PCEA), on cortisol and prolactin levels during the first 48 h postoperatively. Ninety-two patients scheduled for a lower abdominal surgery, were randomly assigned to one of three study groups: IOR (N=31), PCA (N=31), and PCEA (N=30). Patients of the IOR group received postoperatively 50-75 mg of pethidine IM on demand. Patients of the PCA group received a loading dose of morphine (3-4 mg), followed by 1mg bolus of morphine IV per demand. Patients of the PCEA group received 3 ml of 0.1% bupivacaine plus 2 microg/ml of fentanyl per demand, with continuous background infusion of 6ml/h. Venous blood samples were collected preoperatively, and 24 and 48 h after surgery, and were later assayed for serum cortisol and prolactin levels. Patients of the PCEA group exhibited diminished postoperative elevation of serum cortisol levels at 24 and 48 h (24.4, 18.6 microg/dl, respectively) compared with both IOR (31.9, 21.9) and PCA (28.5, 22.3) groups. Similarly, patients of the PCEA group exhibited diminished postoperative elevation of serum prolactin level (20.7, 15.7 ng/mL) compared with PCA (24.9, 17.1) group. The present results indicate that the PCEA technique offers an advantageous treatment associated with reduced postoperative pain, and attenuated neuroendocrine response.

Effects of morphine, fentanyl and tramadol on human immune response

Morphine has been reported to suppress human immune response. We aimed to observe the effects of morphine, fentanyl and tramadol on NF-kappa B and IL-2 from both laboratory and clinical perspective. Jurkat cells were incubated with ten times clinically relevant concentrations of morphine, fentanyl and tramadol before being stimulated with PMA. NF-kappa B binding activity and IL-2 levels were measured. In the clinical study, 150 consenting patients were randomized into 3 groups according to the analgesics used in them, namely, group morphine (M), group fentanyl (F) and group tramadol (T). IL-2 was measured preoperatively and 1, 3 and 24 h after operation. Consequently, NF-kappa B activation was suppressed by morphine and fentanyl but not by tramadol. IL-2 was significantly decreased by morphine and fentanyl but not by tramadol in vitro. In the PCA patients, IL-2 was decreased in group M and increased in group F postoperatively. Whereas in group T, IL-2 was unchanged 1 h after operation but was significantly elevated 3 and 24 h after operation. Our results showed that the inhibition of morphine on IL-2 was most probably related to its suppression on NF-kappa B. Fentanyl had different effects on human immune response in vitro and in vivo. Tramadol may have immune enhancing effect.

The role of COX-2 inhibitors in the perioperative setting: efficacy and safety--a systematic review

A new class of nonsteroidal anti-inflammatory drugs (NSAIDs) selective for cyclooxygenase-2 (COX-2) offers new options for managing perioperative pain. However, new and conflicting data have emerged regarding all nonsteroidal anti-inflammatory drugs, including those selective for COX-2. The data highlight the potential for increased risks of adverse cardiovascular events associated with all NSAIDs and of potential serious skin reactions and gastrointestinal bleeding with specific agents. As of June 2005, the National Institutes of Health and Food and Drug Administration suspended all clinical trials involving NSAIDs. This article reviews 30 prospective studies on the role of COX-2 selective inhibitors in the perioperative setting. The studies examined a variety of variables, including efficacy, perioperative opioid reduction, and effects on platelet aggregation and renal function. The data reveal an overall reduction in postoperative opioid use and significant patient satisfaction with perioperative COX-2 use, no effect on platelet aggregation, and a minor negative effect on renal function. The literature suggests that perioperative use of selective COX-2 inhibitors can be well tolerated and efficacious in carefully selected patient groups. Further data are needed to fully examine the role of these drugs in the perioperative setting. Intensive research into cardiovascular issues surrounding all NSAIDs is warranted.

Effect of 2 anesthetic techniques on the postoperative proinflammatory and anti-inflammatory cytokine response and cellular immune function to minor surgery

STUDY OBJECTIVE

The aim of this study was to investigate the influence of 2 established anesthetic techniques: total intravenous anesthesia and balanced inhalation anesthesia (BAL) on the perioperative-induced changes of peripheral blood mononuclear cells (PBMCs), changes in lymphocyte subsets, and the balance of proinflammatory and anti-inflammatory cytokines.

DESIGN

This is a prospective, randomized, clinical comparison study.

SETTINGS

This study was set at a university hospital.

PATIENTS

This study involved 50 patients with American Society of Anesthesiologists physical status I who were scheduled for elective minimal invasive partial diskectomy.

INTERVENTIONS

There was no intervention involved in this study.

MEASUREMENTS

Changes in differential counts, lymphocyte subsets, and proliferation rates were determined before surgery and in the early postoperative period. Plasma concentrations of proinflammatory cytokines (IL-2, IL-6, IL-12, interferon gamma) and anti-inflammatory cytokines (IL-10, IL-1RA, transforming growth factor beta), and plasma concentrations of cortisol, epinephrine, and norepinephrine were measured before, during, and after surgery.

MAIN RESULTS

Absolute number of CD3+, CD4+, and CD8+, and expression of HLA-DR and activation marker CD25+, CD26+, and CD69+ decreased more in response to surgery after BAL. Changes in distribution of T-lymphocyte cells seem to be in part related to severe postoperative pain. Plasma concentration of IL-6 significantly increased during and after surgery with BAL without relation to pain.

CONCLUSION

Anesthetic management may have varying influences on the postoperative immune response. Surgery-induced inflammatory response and alteration in cell-mediated immunity seem to be more pronounced after BAL. These effects were attributed to the enhanced stress response after BAL.

Effects of preincisional ketamine treatment on natural killer cell activity and postoperative pain management after oral maxillofacial surgery

Poorly controlled pain may lead to increased risk of cancer metastasis by suppressing natural killer (NK) cell activity. Ketamine may be beneficial by potentiating opioid-induced analgesia. We enrolled 59 participants in a randomized double-blind, placebo-controlled clinical trial and assigned them to receive propofol plus (1) saline, 2 mL; (2) ketamine, 0.5 mg/kg; or (3) ketamine, 1.2 mg/kg, followed by a standardized anesthesia protocol. The visual analogue scale (VAS) and 24-hour opioid consumption measured postoperative pain perception. NK cell activity was measured before and 24 hours after ketamine administration using the chromium 51 release assay. Nonparametric analysis of VAS data revealed that women receiving 0.5 mg/kg of ketamine reported less pain (P <.05) compared with the saline 1.2 mg/kg-ketamine groups. This finding was not evident in men. Comparing opioid consumption among the 3 groups (using analysis of variance) revealed a drug-gender interaction (P < .05): 0.5 mg/kg of ketamine decreased postoperative opioid consumption for women more than for men. Although not statistically significant, women receiving 0.5 mg/kg of ketamine had the least NK cell suppression compared with preoperative values (repeated analysis of variance). These findings suggest that for women, low-dose ketamine may be beneficial.

Surgery-induced immunosuppression and postoperative pain management

Surgery is well-known to result in the suppression of some immune functions; however, the role of perioperative pain has only recently been studied. Pain-relieving anesthesia techniques and perioperative analgesia provide some protection against surgery-induced immune suppression and infectious surgical sequelae, although few studies also assess postoperative pain. Attributing a biological consequence to the observed immune alterations remains an issue in human studies, and the use of immune sensitive tumor models in animals enables the linking of immune changes with disease and a means by which to explore causal relationships among surgery-related pain, immune function, and metastatic development. There is strong evidence in animals that pain-relieving interventions significantly reduce the tumor-enhancing effects of undergoing and recovering from surgery. It cannot be assumed that animal findings are directly applicable to the human condition; however, if such relationships hold in humans, perioperative pain management becomes an important strategy for reducing postoperative sequelae.

Effects of post-operative pain treatment using non-steroidal anti-inflammatory analgesics, opioids or epidural blockade on systemic and local immune responses in children

BACKGROUND

Many studies have been carried out on the effects of anaesthetic drugs and methods on the immune response, but pain and its relief also affect the immune response. We measured systemic immune responses in the blood circulation and local responses in the surgical wound when non-steroidal anti-inflammatory analgesics (NSAIDs), opioids or epidural blockade was used in the peri-operative treatment of pain.

METHODS

Responses were measured in 51 children, aged from 2 to 12 years and undergoing major surgery under balanced anaesthesia. Bolus doses of diclofenac intravenously (i.v.) and rectally (NSAID group), continuous i.v. infusion of oxycodone (opioid group) or continuous epidural infusion of bupivacaine + fentanyl (epidural group) were used peri-operatively for pain relief.

RESULTS

The only difference related to the analgesic method was shorter duration of post-operative leucocytosis and lower phytohaemagglutinin (PHA)-induced lymphocyte proliferative responses in peripheral blood in the opioid group than in the NSAID or epidural groups. By contrast, time-related alterations were seen overall in leucocyte and differential counts, lymphocyte and their subset counts, lymphocyte proliferative responses, and in serum cortisol, C-reactive protein, plasma interleukin-6 and group II phospholipase A2 concentrations and in the appearance of different cell types in the wound.

CONCLUSIONS

Post-operative pain treatments using diclofenac (NSAID), oxycodone (opioid) and epidural blockade have basically similar effects on systemic and local immune responses with only slight, probably clinically unimportant differences in children undergoing surgery under general anaesthesia.

The effects of postoperative pain management on immune response to surgery

Surgery is associated with immune alterations, which are the combined result of tissue damage, anesthesia, postoperative pain, and psychological stress. In the present study, we compared the effects of several postoperative pain management techniques on postoperative immune function. Patients hospitalized for abdominal surgery were randomly assigned to one of three postoperative pain management techniques: opiates on demand (intermittent opiate regimen [IOR]), patient-controlled analgesia (PCA), and patient-controlled epidural analgesia (PCEA). Postoperative pain was assessed. Blood samples were collected before and 24, 48, and 72 h after surgery. Production of interleukin (IL)-1beta, IL-2, and IL-6, natural killer cell cytotoxicity, and lymphocyte mitogenic responses were assessed. Patients of the PCEA group exhibited lower pain scores in the first 24 h after surgery compared with patients of the IOR and PCA groups. Mitogenic responses were suppressed in all groups in the first 24 h, returned to preoperative values by 72 h in the PCEA group, but remained suppressed in the PCA group. Production of IL-1beta and IL-6 increased in the IOR and PCA groups, whereas it remained almost unchanged in the PCEA group. Patients receiving an epidural mixture of opiate and local anesthetics (PCEA group) exhibited reduced suppression of lymphocyte proliferation and attenuated proinflammatory cytokine response in the postoperative period.

Pain resolution after lumbar disc surgery is influenced by macrophage tissue infiltration. A prospective consecutive study on 177 patients

The aim of this study was to assess the influence of inflammatory reactions in herniated lumbar disc specimens on pain resolution after lumbar disc surgery. Disc specimens of 200 patients who underwent surgery for lumbar disc herniation were studied immunohistologically. Preoperatively each patient received a verbal rating scale (VRS) for classification of the pain level and general clinical data were recorded prospectively. Varying amounts of macrophages could be demonstrated. Eighty-nine percent of patients could be followed up for a mean period of 7 months. A statistically significant correlation between the histologically observed macrophage infiltration and postoperative pain grading according to the VRS was found. Patients with evidence of inflammatory reactions rated their postoperative complaints lower than patients with no evidence of inflammatory reactions on the VRS (P = 0.04). In our study, a statistically significant correlation between inflammatory changes in the herniated lumbar disc specimen and outcome after lumbar disc surgery could be demonstrated.

Evidence that postoperative pain is a mediator of the tumor-promoting effects of surgery in rats

We have previously shown in rats that the provision of analgesic doses of morphine significantly reduces the tumor-promoting effects of undergoing and recovering from surgery. Because morphine had no effect in non-operated animals, and because a single preoperative dose given hours before tumor inoculation was effective, we have suggested that it is the pain-relieving effects of the drug that underlies its beneficial impact. To support and strengthen this suggestion, two different regimens of analgesia were employed, the systemic administration of the more selective mu-agonist, fentanyl, and the intrathecal (i.t.) administration of bupivacaine plus morphine. To assess host resistance against metastasis, we used a lung clearance assay of the MADB106 mammary adenocarcinoma, a natural killer (NK)-sensitive syngeneic cell line that metastasizes only to the lungs. Female and male Fischer 344 rats were randomly assigned to one of four groups using a 2x2 experimental design: experimental laparotomy under halothane anesthesia versus anesthesia alone, by drug treatment versus vehicle. In the first in vivo experiment, fentanyl was administered 20 min before surgery (40 microg/kg subcutaneously (s.c.)), and at the end of surgery in a slow-release suspension (20 microg/kg s.c.). In the second in vivo experiment, bupivacaine (10 microg) plus morphine (20 microg) in 50 microl was administered i.t. before surgery. Surgery resulted in a 3- to 4-fold increase in the lung retention of MADB106 cells in both males and females, and the observed surgery-induced increase in lung tumor retention was reduced by more than 65% in the fentanyl-treated animals and more than 45% in the animals receiving i.t. bupivacaine plus morphine. Neither drug regimen exerted effects in the anesthesia only animals. Surgery also resulted in a significant suppression of whole blood NK activity assessed at 5 h postoperatively, the same time point at which MADB106 tumor cells were inoculated in the in vivo studies. Unlike the in vivo study, fentanyl suppressed NK activity at this time point in non-operated rats, but had no effect in operated rats. Taken together, these findings strengthen the suggestion that the management of perioperative pain is a critical factor in preventing surgery-induced decreases in host resistance against metastasis. If similar relationships between pain and metastasis occur in humans, then pain control must become a priority in the postoperative care of individuals with cancer.

Pain, analgesic use, and morbidity in appendectomy patients

Pain has immunosuppressive effects among the critically and chronically ill, and opioids may immunomodulate pain's deleterious effects. However, little is known about the relations between acute pain, acute illness, and morbidity among previously healthy surgical patients. This study retrospectively examined these relations in appendectomy patients (N = 61). Eleven patients (18%) had morbidity, with atelectasis (11.5%) the most frequent complication. There were no differences between those patients with and without morbidity and pain intensity, method of opioid administration, and total opioid dose. Patients who received nonopioid analgesics received fewer opioids, less preemptive analgesia, and had less morbidity, whereas patients whose appendixes perforated received higher opioid doses and received more preemptive analgesia. Although the relations between acute pain, opioid use, and morbidity among previously healthy surgical patients are unclear, findings infer that clinical practice does not follow guidelines advocated by analgesic experts.

The immune-suppressive nature of pain

OBJECTIVES

To review evidence that the immune system plays a role in controlling the spread of cancer and findings that perioperative pain relief improves immune status and health outcomes.

DATA SOURCES

Research studies and review articles pertaining to immunity, immune function, stress, and immune-suppressive nature of pain.

CONCLUSIONS

Pain not only results in suffering but is a pathogen itself, capable of facilitating the progression of metastatic disease. Adequate pain relief decreases these risks.

IMPLICATIONS FOR NURSING PRACTICE

Adequate pain relief is not only a primary concern in caring for individuals in pain but may be a matter of physiologic necessity as further studies reveal the immune-suppressive nature of pain.

The role of LGL/NK cells in surgery-induced promotion of metastasis and its attenuation by morphine

Painful stress such as surgery has been shown both to suppress immune function and to promote metastasis, although the degree to which alterations in immunity underlies the tumor-enhancing effects of surgery remains unclear. We recently reported that an experimental laparotomy results in a twofold increase in the number of lung metastases following iv injection of MADB106 tumor cells, a natural killer (NK)-sensitive mammary adenocarcinoma cell line, syngeneic to the Fischer 344 rats we studied. Further, the administration of an analgesic dose of morphine prevented these metastatic-enhancing effects of surgery. The aim of the present study was to investigate the role of NK cells in both the metastatic-enhancing effects of surgery and the attenuation of these effects by morphine. Using a simple 2 x 2 experimental design (surgery with anesthesia vs anesthesia only, and morphine vs vehicle), we found that surgery resulted in a decrease in both whole blood NK cytotoxic activity and number of circulating LGL/NK cells assessed 4 h postoperatively. In a second experiment involving an 18-h lung clearance assay, we used the mAb 3.2.3 to deplete rats of LGL/NK cells with the following rationale: if LGL/NK cells are necessary to mediate an event, then in their absence, that event should not occur. Normal and LGL/NK-depleted animals were assigned to the same four experimental groups, and radiolabeled MADB106 tumor cells were injected iv 4 h after surgery. In normal animals, there was a significant interaction between surgery and morphine such that morphine attenuated the surgery-induced increase in tumor cell retention without affecting tumor cell retention in the anesthesia groups. In the LGL/NK-depleted animals, however, although the tumor-enhancing effects of surgery remained evident, morphine did not mitigate this outcome. These results suggest that: (a) both LGL/NK cell activity and other factors independent of LGL/NK cells play a role in the surgery-induced increase in tumor cell retention; and (b) LGL/NK cells play a critical role in morphine's attenuating effects on this outcome. Finally, these results reinforce concern about the pathogenic consequences of unrelieved pain.