Balanced ultrafiltration, modified ultrafiltration, and balanced ultrafiltration with modified ultrafiltration in pediatric cardiopulmonary bypass.

This study evaluates the effect of balanced ultrafiltration, modified ultrafiltration, and balanced ultrafiltration with modified ultrafiltration on inflammatory mediators in children's open-heart surgery. Eighty children with congenital heart disease were randomly divided into four groups: control group (C group); balanced ultrafiltration group (BUF group); modified ultrafiltration group (MUF group); and balanced ultrafiltration with modified ultrafiltration group (B+M group). Clinical data of these groups were similar. Tumor necrosis factor (TNF), interleukin-8(IL-8), and E-selectin were measured at the beginning of cardiopulmonary bypass (CPB), 30 min later, at the cessation of CPB, at the cessation of MUF (MUF group and B+M group), and 2 hours postoperatively. During CPB, the concentrations of TNF, IL-8, and E-selectin increased significantly in C and MUF groups and did not change significantly in BUF and B+M groups. In the period of MUF, TNF and IL-8 increased; whereas, E-selectin did not change. The study shows that ultrafiltration can filter out the inflammatory mediators, but only BUF can decrease the concentrations of them. Moreover, MUF only can concentrate blood. Combining both techniques has both effects, but the effect of BUF was offset by MUF.     

不同超滤法在小儿体外循环中的应用比较

目的 比较不同超滤法在小儿体外循环中的效果。方法 80例先天性心脏病病儿，随机分成4组，分别为对照（CUF）组，平衡超滤（BUF）组，改良超滤（MUF）组和平衡超滤＋改良超滤（B＋M）组。在围术期检测肿瘤坏死因子（TNF）、白细胞介素－8（IL－8）和E-selectin的浓度。结果 CUF组各类炎症因子的浓度随转流时间的延长不断上升，BUF和B＋M组停转流时炎症因子的浓度明显低于对照组和MUF组（P＜0．05）。MUF组进行超滤时，炎症因子浓度上升，红细胞压积不断升高，B＋M组在停体外循环时炎症介质浓度较低，但在改良超滤时上升，上升幅度较MUF组低。结论 平衡超滤法能降低体内炎症介质，改良超滤法可以在术后迅速浓缩血液，但不能降低炎症介质的浓度。平衡超滤和改良超滤结合起来应用，可兼有二者的作用，但仍不能在转流后将炎症介质的浓度保持在相当低的水平。     

Pharmacokinetic analysis of flomoxef in children undergoing cardiopulmonary bypass and modified ultrafiltration

Objective Cardiopulmonary bypass (CPB) induces changes in the pharmacokinetics of drugs. The purpose of this study was to model the pharmacokinetics of flomoxef, a cephalosporin antibiotic, in pediatric cardiac surgery. Methods Each patient received a flomoxef dose of 30 mg/kg as a bolus after the induction of anesthesia and an additional dose (1 g for a child weighing <10 kg, 2 g for ≥10 kg) was injected into the CPB prime. Modified ultrafiltration (MUF) was routinely performed. Blood samples, urine, and ultrafiltrate were collected. In seven patients (group I), serum flomoxef concentration-time courses were analyzed by a modified two-compartment model. Utilizing the estimated parameters, serum concentrations were simulated in another eight patients (group II). Results The initiation of CPB resulted in an abrupt increase in serum flomoxef concentrations in group I; however, concentrations declined biexponentially. The amount of excreted flomoxef in the urine and by MUF was 47% ± 8% of the total administered dose. In group II, an excellent fit was found between the values calculated by the program and the observed serum concentrations expressed; most of the performance errors were <1.0. There was no difference in any kinetic parameter between group I and groups I + II (n = 15). Conclusion The pharmacokinetics of flomoxef in children undergoing CPB and MUF were well fitted to a modified two-compartment model. Using the kinetic data from this study, the individualization of dosage regimens for prophylactic use of flomoxef might be possible.     

Antioxidant therapy with Salvia miltiorrhiza decreases plasma endothelin-1 and thromboxane B2 after cardiopulmonary bypass in patients with congenital heart disease

OBJECTIVE: The endothelium-derived vasoconstrictor endothelin-1 is increased after cardiopulmonary bypass in children with congenital heart defects. This study determines whether antioxidant therapy with Salvia miltiorrhiza injection, an herb extract containing phenolic compounds, prevents the postoperative increase of endothelin-1. The relationship between endothelin-1 and the endothelium-derived prostacyclin (prostaglandin I2) and thromboxane A2 postoperatively is also investigated. METHODS: Twenty children with congenital heart defects and pulmonary hypertension were randomly assigned to group A (placebo control, n=10) or B (200 mg/kg Salvia miltiorrhiza intravenously after anesthesia induction and at the time of rewarming, respectively; n =10) before cardiac surgery. Central venous blood samples were taken before operation (T(0)), 10 (T(1)) and 30 minutes (T(2)) after starting cardiopulmonary bypass, 10 (T(3)) and 30 minutes (T(4)) after aortic declamping, and 30 minutes (T(5)) and 24 hours (T(6)) after termination of cardiopulmonary bypass. Plasma lipid peroxidation product malondialdehyde, myocardial specific creatine kinase-MB activity, thromboxane B2, and 6-keto-prostaglandin F(1 alpha) (stable metabolites of thromboxane A2 and prostaglandin I2) were measured. RESULTS: Malondialdehyde increased significantly at T(1) in group A and remained significantly higher than in group B thereafter (P <.05). Malondialdehyde in group B did not significantly increase over time. At T(5), plasma creatine kinase-MB, thromboxane B2, and endothelin-1 in group B were lower than in group A (P <.05); malondialdehyde correlated significantly with creatine kinase-MB (r = 0.71, P =.0005). At T(6), endothelin-1 negatively correlated with the 6-keto-prostaglandin F(1 alpha)/thromboxane B2 ratio (r = -0.64, P =.0025). CONCLUSION: Antioxidant therapy reduces myocardial damage and attenuates postoperative vasoactive mediator imbalance.     

Effect of experimental cardiopulmonary bypass on systemic and transcardiac thromboxane B2 levels

Systemic and cardiac metabolism of thromboxane was studied in a canine model (n = 13) of standard cardiopulmonary bypass and surgical cardioplegia. Sterile techniques were applied and no donor blood was used. Systemic samples (thoracic aorta) and transcardiac gradients (coronary sinus - aortic root) were obtained (1) 5 minutes after cannulation, (2) 20 minutes after the onset of partial bypass, (3) 5 seconds after the first administration of cardioplegic solution (CP-1), and (4) 5 seconds after the second administration of cardioplegic solution (CP-2). Cardioplegic doses were administered 30 minutes apart and consisted of 500 ml of hypothermic (8 degrees C), hyperkalemic (25 mEq potassium chloride) solution infused into the aortic root at 60 to 70 mm Hg. Thromboxane B2 was determined by a double-antibody radioimmunoassay (picograms per milliliter +/- standard error of the mean). Onset of partial bypass was followed by a significant rise in systemic arterial thromboxane B2 levels: after cannulation, 115 +/- 21 pg/ml; after the onset of partial bypass, 596 +/- 141 pg/ml; p less than 0.01). Significant transcardiac thromboxane B2 gradients were found during the first and second cardioplegic washouts (CP-1: aortic root 73 +/- 12 pg/ml, coronary sinus 306 +/- 86 pg/ml, p less than 0.01; CP-2: aortic root 65 +/- 11 pg/ml, coronary sinus 355 +/- 98 pg/ml, p less than 0.01). Transcardiac gradients of 6-keto-prostaglandin F1 alpha and thromboxane B2 were obtained at CP-1 and CP-2. Gradients of 6-keto-prostaglandin F1 alpha were not different from thromboxane B2 gradients during CP-1 but were significantly higher than thromboxane B2 gradients during CP-2. In a subgroup of five dogs, transcardiac thromboxane B2, lactate, and platelet gradients were measured simultaneously. Cardiac thromboxane B2 generation was found only in the presence of cardiac lactate production. Transcardiac platelet gradients were significantly higher at CP-1 (13,900 +/- 3,000/mm3) than at CP-2 (4,000 +/- 1,230/mm3) (p less than 0.05), whereas thromboxane B2 gradients were similar at CP-1 and CP-2. Our study demonstrates that thromboxane B2 is released into the coronary circulation during surgical cardioplegic arrest with anaerobiosis.     

Lipid peroxide and leukotriene B3 production in patients undergoing cardiopulmonary bypass

Cardiac surgery with cardiopulmonary bypass (CPB) is frequently associated with a complex array of post-operative clinical abnormalities, including low-output syndrome and pulmonary dysfunction. It has been reported that oxygen free radicals are one of the important factors causing reperfusion injury. To determine whether oxygen free radicals are produced during cardiac surgery, we studied nine patients anesthetized with high doses of fentanyl. Lipid peroxide (LPO) and leukotriene B₄ (LTB₄) levels increased significantly from 60 min after aortic ligation to 180 min after reperfusion (aortic declamping), compared with the levels before surgery, while superoxide dismutase (SOD) was not affected markedly. Creatine kinase (CK), CK muscle-brain (CK-MB), and neutrophils increased from 60 min after aortic declamping. Correlations were not observed between LPO and CK nor between LPO and CK-MB. These results suggest that free radicals are generated during cardiac surgery with cardiopulmonary bypass (CPB), but it is unclear whether free radicals cause tissue injury after cardiac surgery with CPB.     

Veno-arterial modified ultrafiltration in children after cardiopulmonary bypass.

A method of performing veno-arterial modified ultrafiltration is described that utilizes conventional blood flow through the aortic and venous cannulae. A dual-pump blood cardioplegia console is adapted to aspirate blood from the cardiopulmonary bypass venous line. The blood is ultrafiltered, sent through the cardioplegia heat exchanger, and returned to the aorta via the cardioplegia needle. Veno-arterial modified ultrafiltration has produced no visual evidence of air entrainment in the cardiopulmonary arterial line. This method allows the immediate resumption of cardiopulmonary bypass without the need for the surgeon to recannulate or alter tubing. Thirty-five children underwent veno-arterial modified ultrafiltration; the results show significant increases in postoperative hematocrit, early extubation, and improved rheology.     

The effect of modified ultrafiltration on the amount of circulating endotoxins in children undergoing cardiopulmonary bypass

OBJECTIVE: To determine whether the use of modified ultrafiltration during pediatric cardiopulmonary bypass (CPB) diminishes the load of circulating endotoxins. DESIGN: Single-arm prospective observational study. SETTING: A university hospital operating room and intensive care unit. PARTICIPANTS: Twenty children undergoing CPB for correction of various congenital heart diseases. INTERVENTIONS: The amount of endotoxins in plasma was measured during CPB and before and after modified ultrafiltration. The ultrafiltrate was assayed for the presence of endotoxins. Postoperatively, the children were followed with relevant infectious parameters and cultures. MEASUREMENTS AND MAIN RESULTS: The amount of endotoxins increased significantly during the CPB procedure (from a median of 1.3 ng [range, 0 to 13.7 ng] to 24.2 ng [range, 2.1 to 75.9 ng]). After termination of CPB, modified ultrafiltration was shown to lower the amount of circulating endotoxins in blood (from a median of 24.2 ng [range, 2.1 to 75.4 ng] to 9.0 [range, 0.1 to 40.6 ng]). The major bulk of this reduction in endotoxin load was retrieved in the ultrafiltrate (median of 11.9 ng [range, 0 to 12.1 ng]). CONCLUSION: This study strongly suggests that modified ultrafiltration decreases the amount of circulating endotoxins in children undergoing cardiac surgery.     

Effect of hypothermia on rectal mucosal perfusion in infants undergoing cardiopulmonary bypass

We have examined the effect of profound hypothermia on gut mucosal perfusion in 20 infants, aged 1.4-45 weeks, requiring cardiopulmonary bypass (CPB). After induction of anaesthesia, a laser Doppler probe was inserted 8 cm into the patient's rectum to allow monitoring of rectal mucosal perfusion ("flux") throughout operation. Steady-state observation periods (5 min with no change in temperature or mean arterial pressure (MAP) were achieved after 10 min on CPB at 35 degrees C, after CPB-induced cooling to 15-25 degrees C, immediately before rewarming and after rewarming to 35 degrees C. Throughout these periods flow rate was 100 ml kg-1 min-1, packed cell volume was kept constant and Paco2 maintained at 5.3 +/- 0.5 kPa. No vasoactive drugs were used. Initial warm and rewarm MAP values (46 mm Hg) were significantly lower (P = 0.008) than during the cold CPB periods (63 and 64 mm Hg). Mean flux in the first cold period (152) was significantly lower (P = 0.001) than that in the first warm CPB period (211). Post-rewarm flux (127) was significantly lower than all other CPB flux values (P = 0.004). We conclude that although hypothermia significantly reduced mucosal blood flow, rewarming produced even greater reductions in mucosal perfusion that may prove crucial in the development of mucosal hypoxia.      

强化胰岛素治疗对心肺转流术患者心血管功能的影响

目的 探讨强化胰岛素治疗对心肺转流术(CPB)患者血浆一氧化氮(NO)和内皮缩血管肽1(ET-1)表达的影响.方法 36例心脏瓣膜置换术患者随机分为常规治疗组(RT,n=18)和强化胰岛素治疗组(IT,n=18).RT组术中血糖变化不作处理,术后控制在13.9 mmol/L以内;IT组血糖术中控制在3.9～10.0 mmol/L,术后在3.9～6.1 mmol/L.分别于术前、CPB开始时及CPB结束后不同时间点测量两组患者的血浆NO和ET-1水平.结果 RT组血浆NO含量在CPB开始时即略有下降,CPB结束时达到最低(P＜0.05);此后回升,CPB结束后48 h时接近术前水平.RT组血浆ET-1含量在CPB开始时即开始升高,CPB结束时达高峰(P＜0.01);此后下降,至CPB结束后24 h时降至术前水平.IT组各时间点的血浆NO和ET-1含量与术前比较均无差异.结论 强化胰岛素治疗可减小CPB心脏手术中所致NO和ET-1的变化幅度,对心血管功能具有保护作用.     

An analysis of oxygen consumption and oxygen delivery in euthermic infants after cardiopulmonary bypass with modified ultrafiltration

Background

The balance between systemic oxygen consumption (V?O₂) and delivery (DO₂) is impaired after cardiopulmonary bypass (CPB) and is related to systemic inflammatory response syndrome. We sought to assess V?O₂ and DO₂ and their relationship with proinflammatory cytokines after CPB with the use of modified ultrafiltration (MUF) in infants.

Methods

Sixteen infants, aged 1-11.5 months (median, 6.3 months), undergoing hypothermic CPB with MUF were studied during the first 12 hours after arrival in the intensive care unit (ICU). The central temperature was maintained at 36.8-37.1°C using external cooling or warming. V?O₂ was continuously measured using respiratory mass spectrometry. Arterial blood samples for the tumor necrosis factor (TNF), interleukin-6 (IL-6), and interleukin-8 (IL-8) were taken and DO₂ was calculated using the Fick principle on arrival at the ICU, and 2, 4, 8, and 12 hours postoperatively. Cytokines were additionally measured after induction of anesthesia and at the end of MUF.

Results

V?O₂ significantly decreased by 18.8% during the study period. DO₂ was depressed throughout this period and reached a nadir at 8 hours (357.1 ± 136.2 ml · min⁻¹ · m⁻²). The decrease in cytokines was accompanied with the decrease in V?O₂ despite varied relationships between the levels of each of the cytokines and V?O₂ measurements.

Conclusions

Our data indicate an unusual continuous decrease in V?O₂ during the first 12 hours after CPB in infants. Control of body temperature to maintain euthermia in addition to the use of MUF may be beneficial to the balance between V?O₂ and DO₂ in the early postoperative period.     

Synergism between leukotriene B4 and thromboxane A2 in mediating acid-aspiration injury.

Acid aspiration leads to thromboxane-dependent lung neutrophil sequestration associated with microvascular permeability increase. Leukotriene B4 (LTB4) is postulated to be a cofactor in the thromboxane-induced inflammatory response. This study tests the interaction between LTB4 and thromboxane, focusing on LTB4 induction of thromboxane-dependent lung neutrophil sequestration after acid aspiration. Anesthetized rats underwent tracheostomy and insertion of a cannula in a left lung segment. This was followed by instillation of either 0.1 ml 0.1N hydrochloric acid (n = 18) or 0.1 ml saline in control rats (n = 18). When assayed at 3 hours, acid aspiration led to increased plasma levels of LTB4 and thromboxane B2 (TxB2), higher than control values (p less than 0.05). The rise in plasma LTB4 was correlated (p less than 0.05; r = 0.83) with sequestration of neutrophils in the nonaspirated lung. The entrapment of thromboxane-dependent lung neutrophil was associated with an increase in protein concentration in bronchoalveolar lavage of the aspirated and nonaspirated sides and an increase in lung wet to dry weight ratio. Pretreatment of other rats (n = 18) with the lipoxygenase inhibitor diethylcarbamazine IV prevented an aspiration-induced rise in plasma LTB4 and TxB2. Further, there was an attenuation of lung leukosequestration and protein leak in bronchoalveolar lavage and lung edema (all p less than 0.05). Pretreatment of other rats (n = 12) with the leukotriene receptor antagonist FPL 55712 IV did not prevent the aspiration-induced rise in LTB4 or TxB2, but otherwise was as effective as diethylcarbamazine in preventing injury. Finally, other hydrochloric acid-aspirated rats (n = 8) were pretreated intravenously with the thromboxane synthetase inhibitor OKY 046 or the thromboxane receptor antagonist SQ 29548. Both agents limited the aspiration-induced rise in plasma LTB4 (p less than 0.05). The data indicate that localized acid aspiration induces synthesis of LTB4 and thromboxane A2. Inhibition of either leukotriene or thromboxane will limit PMN adhesion and increased lung permeability.     

Effect of ultrafiltration on plasma colloid oncotic pressure and red cell volume during cardiopulmonary bypass

Forty cardiopulmonary bypass patients were randomized into two matchable groups, an ultrafiltration and an control group. We have concluded that change of plasma colloid oncotic pressure may be a more sensitive parameter of monitoring the effect of ultrafiltration during cardiopulmonary bypass.     

Thyroid hormones levels in infants during and after cardiopulmonary bypass with ultrafiltration

Objective: The aim of this study was to find out if infants after cardiopulmonary bypass develop non-thyroidal illness and if illness severity after cardiopulmonary bypass depends on hormone concentration in ultrafiltrate. Methods: Thyroid hormone status was assessed in 20 infants with congenital heart defects undergoing cardiac surgery (age range 7 days–11 months). Blood samples were collected preoperatively, during cardiopulmonary bypass, after cardiopulmonary bypass, and also postoperatively in 1, 2, 3, and 8 day after cardiac surgery. Plasma thyrotropin, thyroxine, free thyroxine, triiodothyronine, free triiodothyronine and reverse triiodothyronine were measured in blood samples and also in ultrafiltrate. Results: All patients had reduction in serum thyrotropin, thyroxine, free thyroxine, triiodothyronine, free triiodothyronine, and elevation of reverse triiodothyronine after cardiac surgery. In all patients we performed ultrafiltration. Patients were divided in to two groups. (with and without prolonged recovery). In the group of patients with prolonged recovery we noticed significantly higher amount of triiodothyronine per kilogram body weight. One of these patients died. The average level of total thyroxine decreased from the level 126 nmol/l before bypass to the minimal level 73 nmol/l after bypass, free thyroxine from the level 18 pmol/l before bypass to the minimal level 12 pmol/l after bypass. The average level of total triiodothyronine decreased from the level 1.54 nmol/l before bypass to the minimal level 0.42 nmol/l after bypass, free triiodothyronine from the level 6.12 pmol/l before bypass to the minimal level 3.21 pmol/l after bypass. The average level of TSH decreased from the level 4.31 mU/l before bypass to the level 0.64 mU/l after bypass. The average level of reverse-triiodothyronine increase from the level 0.83 nmol/l before bypass to the maximal level 1.94 nmol/l after bypass. Conclusions: We conclude that non-thyroidal illness occurs in all infants after cardiopulmonary bypass. The amount of free triiodothyronine that is filtrated during cardiopulmonary bypass may influence postoperative recovery.     

Angiotensin II concentrations and gut mucosal perfusion in infants undergoing cardiopulmonary bypass.

OBJECTIVES: To determine whether hypothermic cardiopulmonary bypass (CPB) per se causes an increase in angiotensin II (A-II) concentration in infants and to investigate the relationship between A-II concentration and gut mucosal perfusion. DESIGN: Prospective, open, nonrandomized, observational study. SETTING: Children's teaching hospital. PARTICIPANTS: Thirty acyanotic infants requiring CPB. INTERVENTIONS: A-II concentrations were measured on six occasions before, during, and after CPB. An orogastric tonometer allowed intermittent calculations of gastric intramucosal pH (pHi). Gastric mucosal blood flow (flux) was monitored using a laser Doppler flowmeter. Ten infants acted as controls (group 1); 10 infants received captopril, 0.9 mg/kg orally, 45 minutes before induction of anesthesia (group 2), and 10 infants received enalaprilat, 0.06 mg/kg intravenously, just before CPB (group 3). MEASUREMENTS AND MAIN RESULTS: A-II concentrations were abnormally high in 28 of 30 patients before CPB (median, 450 pg/mL (range, 83 to 5,787 pg/mL). A-II concentrations in groups 1 and 2 decreased during CPB, but values remained at twice normal levels throughout surgery (median, 171 to 198 pg/mL post-CPB). A-II concentrations remained normal (range, 52 to 120 pg/mL) during and after CPB in patients receiving enalaprilat (group 3). The authors found no significant correlation between A-II concentration and pHi or flux before, during, or after surgery. CONCLUSIONS: Acyanotic infants requiring cardiac surgery may have high perioperative concentrations of A-II. Hypothermic CPB is associated with a decrease in A-II concentration. Reductions in gut mucosal perfusion seen in some infants during hypothermic CPB are not related to increases in A-II concentrations.     

改良超滤对婴幼儿心脏手术输血的影响

目的　观察改良超滤技术在婴幼儿体外循环心血管手术中对输血及术后出血的影响。方法　 6 0例接受体外循环下心血管手术的先天性心脏病患儿 ,均分为对照组 (不接受任何超滤 )、常规超滤组 (CUF组 )和改良超滤组 (MUF组 )。观察术中库血用量、血浆用量、血球压积的变化及术后2 4h出血量 ,并用SSPS/PC进行统计学处理。结果　MUF组库血用量、血浆用量、术后 2 4h出血量显著低于对照组和CUF组 (P <0 0 1) ,且滤出水量明显多于CUF组 (P <0 0 1)。结论　在婴幼儿心血管手术中 ,改良超滤可有效排出体内水分 ,提高血球压积 ,明显减少输血及术后出血 ,是节约用血的重要手段之一。     

Effects of dilutional and modified ultrafiltration in plasma endothelin-1 and pulmonary vascular resistance after the Fontan procedure

BACKGROUND: Pulmonary vascular resistance (PVR) is closely related with patients' hemodynamics after the Fontan procedure and endothelin-1 (ET-1) may play an important role in pulmonary circulation. Modified ultrafiltration (MUF) is known to remove inflammatory mediators after cardiopulmonary bypass (CPB) surgery. The time courses of plasma ET-1 and PVR were examined before and after the Fontan procedure with MUF. METHODS: Twenty-two patients who underwent the Fontan procedure were divided into two groups: a dilutional ultrafiltration/modified ultrafiltration (DUF/MUF) group (n =11) and a control group (n = 11). Conventional ultrafiltration was performed during CPB in the control group. DUF was performed semicontinuously during CPB and MUF was continued until 15 to 20 minutes after the CPB with polyacrylonitonile membrane in the DUF/ MUF group. The plasma ET-1 concentration was measured before and after CPB, after MUF in the DUF/MUF group, and 6 and 24 hours after CPB. PVR was calculated simultaneously using a thermodilutional catheter. RESULTS: Plasma ET-1 levels increased significantly after CPB in the control group but they did not increase immediately after CPB in the DUF/MUF group. Similarly, PVR increased significantly after CPB in the control group but it did not increase after CPB in the DUF/MUF group and remained low at 6 and 24 hours after CPB. CONCLUSIONS: DUF and MUF suppress the increase in the plasma ET-1 concentration that occurs immediately after the completion of the Fontan procedure and may be an effective intervention for maintaining low PVR after the procedure.     

Roles of thromboxane A2 and leukotriene B4 in radicular pain induced by herniated nucleus pulposus.

Biologically active substances, such as prostaglandins, thromboxanes, and leukotrienes, which are metabolites involved in the arachidonic acid cascade, are detected in herniated disc samples obtained from patients with lumbar disc herniation. However, little is known concerning the relationships between these substances and clinical symptoms such as radicular pain. Thromboxane A2 (TXA2) induces not only potent platelet aggregation, but also blood vessel contraction. Leukotriene B4 (LTB4), a potent chemotactic agent, plays a role in inflammatory reactions by recruiting neutrophils and lymphocytes. The purpose of this study was to examine the roles of TXA2 and LTB4 in the hyperalgesia induced by application of nucleus pulposus to the lumbar nerve root in the rat. TXA2 synthetase inhibitor and LTB4 receptor antagonist, which were injected into the epidural space, decreased mechanical hyperalgesia at both three and seven days after epidural injection. There were no significant differences in sensitivity to noxious thermal stimuli following application of the nucleus pulposus or an epidural injection. Epidural injection of LTB4 receptor antagonist and/or TXA2 synthetase inhibitor may attenuate the painful radiculopathy due to lumbar disc herniation. In conclusion, our findings suggest that TXA2 and LTB4 may play significant roles in mechanical hyperalgesia induced by autologous nucleus pulposus.