Glomerular filtration rate is increased in burn patients.

Urinary output, a key parameter guiding fluid resuscitation in burn trauma, is an inadequate measure of renal function. In this study, the clearance of iohexol (CL) was used to follow the glomerular filtration rate during the first week after burn. Nineteen adults with major burns received an intravenous bolus injection of iohexol every other day. Plasma concentration of iohexol was measured over 4h and CL was calculated by a one-compartment kinetic model. The results were compared to the CL as obtained by a two-compartment model and also to the CL measured in 10 healthy controls. The results show that CL values for burn patients were high. The first day after burn, median CL was 155 mL/min/1.73 m(2) (range 46-237), which exceeded that for the controls (mean 117 mL/min/1.73 m(2); P<0.01). However, on day 7 the CL approached the expected baseline (mean 122 mL/min/1.73 m(2)). CL was 10% lower when calculated from two-compartment kinetics, and a correction factor of 0.9 was applied to all results obtained by the one-compartment calculations to give results comparable to those from the two-compartment kinetics. In conclusion, CL is increased early after burn. The mechanism is unclear but it parallels the period of vascular dysfunction and increased cardiac output.

Tranexamic acid decreases external blood loss but not hidden blood loss in total knee replacement.

BACKGROUND: Total knee arthroplasty (TKA) is often carried out using a tourniquet and shed blood is collected in drains. Tranexamic acid decreases the external blood loss. Some blood loss may be concealed, and the overall effect of tranexamic acid on the haemoglobin (Hb) balance is not known. METHODS: Patients with osteoarthrosis had unilateral cemented TKA using spinal anaesthesia. In a double-blind fashion, they received either placebo (n=24) or tranexamic acid 10 mg kg(-1) (n=27) i.v. just before tourniquet release and 3 h later. The decrease in circulating Hb on the fifth day after surgery, after correction for Hb transfused, was used to calculate the loss of Hb in grams. This value was then expressed as ml of blood loss. RESULTS: The groups had similar characteristics. The median volume of drainage fluid after placebo was 845 (interquartile range 523-990) ml and after tranexamic acid was 385 (331-586) ml (P<0.001). Placebo patients received 2 (0-2) units and tranexamic acid patients 0 (0-0) units of packed red cells (P<0.001). The estimated blood loss was 1426 (1135-1977) ml and 1045 (792-1292) ml, respectively (P<0.001). The hidden loss of blood (calculated as loss minus drainage volume) was 618 (330-1347) ml and 524 (330-9620) ml, respectively (P=0.41). Two patients in each group developed deep vein thrombosis. CONCLUSIONS: Tranexamic acid decreased total blood loss by nearly 30%, drainage volume by approximately 50% and drastically reduced transfusion. However, concealed loss was only marginally influenced by tranexamic acid and was at least as large as the drainage volume.

Albumin extravasation and tissue washout of hyaluronan after plasma volume expansion with crystalloid or hypooncotic colloid solutions.

BACKGROUND: Intravascular volume expansion is followed by loss of fluid from the circulation. The extravasation of albumin in this readjustment is insufficiently known. METHODS: Twelve male volunteers participated, each in three separate sessions, in a controlled, randomised, open fashion. They received one of the following: albumin 40 g/L,(7.1 mL/kg, i.e. 500 mL per 70 kg); Ringer's acetate (21.4 mL/kg), or dextran 30 g/L (7.1 mL/kg). The fluids were infused during 30 min and the subjects were followed for 180 min. ECG, arterial oxygen saturation and non-invasive arterial pressure were recorded. Haemoglobin, haematocrit, serum albumin and osmolality, plasma colloid osmotic pressure and hyaluronan concentration were determined in venous samples. RESULTS: The serum albumin concentration decreased (P < 0.05, anova) following Ringer's acetate or dextran, whereas serum osmolality was unchanged in all groups. The colloid osmotic pressure decreased (P < 0.05) after the Ringer solution. The blood volume increase was estimated from the decrease in haemoglobin concentration and did not differ between the three fluids. The cumulated extravasation of albumin was largest following albumin (10.4 +/- 5.4 g, mean +/- SD), less following dextran (5.6 +/- 5.0 g) and negligible in the Ringer group (0.5 +/- 10.0 g; P < 0.05 against albumin). However, the Ringer solution increased the plasma concentration of hyaluronan drastically. CONCLUSIONS: Infusion of hypotonic colloidal solutions entails net loss of albumin from the vascular space. This is not the case after Ringer's acetate. Increased interstitial hydration from the latter fluid is followed by lymphatic wash out of hyaluronan.

Effective inhibition of nitric oxide production by aminoguanidine does not reverse hypotension in endotoxaemic rats.

BACKGROUND: Excess production of nitric oxide (NO) by the inducible NO synthase (iNOS) has been implicated in the pathophysiology of septic shock. Using methaemoglobin (metHb) and the stable NO metabolite nitrate as markers of NO formation, we assessed the effect of iNOS blockade by aminoguanidine (AG) on hypotension and NO formation in endotoxaemic rats. METHODS: In 32 male Wistar rats under chloralose anaesthesia, MetHb (at 15 and 330 min, respectively) and plasma nitrate (at 330 min) were determined. Mean arterial pressure, heart rate and haematocrit were monitored. The LPS group (n=8) received bacterial endotoxin (LPS), 3 mg kg(-1) i.v. and was subsequently monitored for 5 h. At 2 h after LPS, the LPS+AG20 group (n=8) received AG, 5 mg kg(-1), and 5 mg kg(-1) h(-1) for the remaining 3 h. The LPS+AG100 group (n=8) instead received 25 mg kg(-1), followed by 25 mg kg(-1) h(-1). The NaCl group (n=8) was given corresponding volumes of isotonic saline. RESULTS: AG decreased the LPS-induced rise in plasma nitrate by about 50% in the LPS+AG20 group. MetHb levels, however, were not appreciably reduced by this dose. Both NO metabolites reached control levels after the higher dose of AG. LPS caused a progressive decrease in haematocrit. AG did not influence the LPS-induced hypotension, tachycardia or haemodilution. CONCLUSION: AG inhibited NO formation in a dose-dependent way. Yet, AG had no haemodynamic effects, suggesting a minor cardiovascular influence of iNOS in this endotoxin model, in parallel to what has been found in microbial sepsis.

Limited effectiveness of intraoperative autotransfusion in major back surgery.

BACKGROUND AND OBJECTIVE: The efficiency of intraoperative autotransfusion in scoliosis surgery is poorly known but needs to be evaluated, not least because of the large blood losses in these patients. This is a retrospective analysis of transfusion requirements of 43 such patients. METHODS: Records from 43 patients were studied. During surgery, the shed blood was salvaged and washed in an autotransfusion device (AT1000 Autotransfusion Unit) and a suspension of red cells was reinfused. RESULTS: Fifty-eight per cent of the intraoperative blood loss was salvaged. The total blood loss during the patients' hospital stay was calculated from the haemoglobin balance; 24% of this loss was salvaged by the device. Moreover, 36 of the patients needed allogeneic blood transfusion. CONCLUSION: The efficiency of the autotransfusion device was relatively low in relation to the total extravasation, mainly because the postoperative blood loss is substantial.

Albumin supplementation during the first week after a burn does not mobilise tissue oedema in humans.

OBJECTIVE: To measure water balance and changes in distribution, and the effect of giving supplementary albumin, early after a burn injury. DESIGN: Consecutive patients (matched groups) and healthy controls. SETTING: National burn unit in a Swedish university hospital. PATIENTS AND SUBJECTS: Eighteen patients with 18%-90% total burned surface area and 16 healthy male control subjects. INTERVENTIONS: The patients were given an intravenous infusion of ethanol over 1 h, 0.35-0.60 g/kg body weight, and a bolus of 3.3 to 6.5 g of iohexol. The control subjects were given the same amounts of either ethanol or iohexol. Patients were subdivided into two groups according to whether or not they received supplementary albumin starting 12 h post-burn. MEASUREMENTS AND RESULTS: Blood samples were drawn at 20-30 min intervals over 4 h after the start of the infusion. Serum ethanol was measured by headspace gas chromatography, and iohexol with high-pressure liquid chromatography (HPLC). Distribution volume was calculated from the concentration-time profiles. Total body water (TBW) was measured by the ethanol tracer and bioelectric impedance (BIA) techniques, and estimated extracellular water (ECWest) by iohexol tracer. They were all significantly increased after a burn. Excess water was accumulated mainly in the extracellular compartment. It declined towards normal values (those of volunteers) at the end of the week. Albumin supplementation did not influence the amount or distribution of the excess fluid. CONCLUSION: Body water increases after a burn. Excess water is mainly deposited in the extracellular space. Tissue oedema fluid is not mobilised by albumin supplementation.

Aminoguanidine does not influence tissue extravasation of albumin in endotoxaemic rats.

BACKGROUND: It is generally maintained that protein and fluid are lost from the circulation under septic conditions. The role played by an increased production of nitric oxide, by the inducible nitric oxide synthase (iNOS), in this process is unclear. METHODS: Chloralose anaesthetised male Wistar rats received E. coli lipopolysaccharide (LPS), 3 mg kg(-1) i.v., and were studied for 5 h. Mean arterial pressure (MAP) and heart rate (HR) were monitored and haematocrit (Hct) was determined intermittently. Tissue plasma volume and tissue clearances of radiolabelled albumin over the last 2 h of the experiment were determined by a double-isotope method. In 8 rats, 2 h after LPS, aminoguanidine, an iNOS selective blocker, was given i.v. at a dose of 5 mg kg(-1). This was followed by a continuous infusion for the duration of the experiment; altogether 20 mg kg(-1) was administered. In the control group (n=8), a corresponding volume of saline was infused. RESULTS: Aminoguanidine did not significantly influence Hct, MAP and HR, as evidenced by inter-group comparisons (Mann-Whitney test). Tissue plasma clearances of albumin and tissue plasma volume were similar in both groups. CONCLUSION: Aminoguanidine at 20 mg kg(-1) did not reverse the haemodynamic changes induced by LPS. Neither did the drug affect the tissue plasma clearance of albumin or the tissue plasma volume.

Blood loss in prosthetic hip replacement is not influenced by the AB0 blood group.

OBJECTIVE: To find out if there is a correlation between AB0 type and the amount of blood lost at operation. DESIGN: Retrospective study. SETTING: One county and one university hospital, Sweden. SUBJECTS: 540 patients who underwent primary prosthetic hip replacement under regional anaesthesia. Albumin (n = 298) or dextran (n = 242) were used as plasma substitutes. MAIN OUTCOME MEASURES: Estimated blood loss and number of units of red cell concentrates transfused. RESULTS: The characteristics of the study groups were similar. In patients given albumin, the mean (SD) intraoperative loss with blood group 0 (n = 100) was 718 (413) ml and 2.7 (1.9) red cell units were given. Those with other blood groups (n = 198) lost 713 (469) ml and were given 2.5 (2.0) units. In patients given dextran with blood group 0 (n = 82), the intraoperative blood loss was 650 (337) ml, the postoperative loss 480 (222) ml and they received 2.1 (2.1) units. The corresponding values in the patients with other blood groups (n = 160) were 665 (351), 498 (208) and 2.5 (2.1) units. CONCLUSION: Blood group 0 was not associated with increased blood loss.

Transesophageal echocardiographic hemodynamic monitoring during preoperative acute normovolemic hemodilution.

BACKGROUND: Preoperative acute normovolemic hemodilution may compromise oxygen transport. The aims of our study were to describe the hemodynamic effects of normovolemic hemodilution and to determine its effect on systolic and diastolic cardiac function by multiplane transesophageal echocardiography. METHODS: In eight anesthetized patients (aged 13-51 yr) without heart disease, hemoglobin was reduced in steps from 123 +/- 8 (mean +/- SD) to 98 +/- 3 and to 79 +/- 5 g/l. Hemodynamic measurements (intravascular pressures, thermodilution cardiac output, and echocardiographic recordings) were obtained during a stabilization period and at each level of hemodilution. Left ventricular wall motion was monitored continuously, and Doppler variables, annular motion, and changes in ejection fractional area were analyzed off-line. RESULTS: During hemodilution, cardiac output by thermodilution increased by 16 +/- 7% and 26 +/- 10%, corresponding well to the increase in cardiac output as measured by Doppler (difference, 0.32 +/- 1.2 l/min). Systemic vascular resistance fell 16 +/- 14% and 23 +/- 9% and pulmonary capillary wedge pressure increased slightly (2 +/- 2 mmHg), whereas other pressures, heart rate, wall motion, and diastolic Doppler variables remained unchanged. Ejection fractional area change increased from 44 +/- 7% to 54 +/- 10% and 60 +/- 9% as a result of reduced end-systolic and increased end-diastolic left ventricular areas. CONCLUSIONS: A reduction in hemoglobin to 80 g/l during acute normovolemic hemodilution does not normally compromise systolic or diastolic myocardial function as determined by transesophageal echocardiography. Preload, left ventricular ejection fraction, and cardiac output increase with a concomitant fall in systemic vascular resistance.

Mild hypothermia does not increase blood loss during total hip arthroplasty.

BACKGROUND: The effects of mild hypothermia on blood loss are little known. METHODS: Patients, undergoing primary prosthetic hip surgery under spinal anaesthesia, were randomised to the operative procedure, with (n=25) or without (n=25) forced air warming. Core temperature was repeatedly measured from the tympanic membrane. The blood loss was calculated by three different methods; the intraoperative loss was estimated visually. The loss during and after the operation was obtained by determination of lost haemoglobin (the Hb-method). The blood loss during hospital stay was also calculated from the haemoglobin balance. RESULTS: Among controls, core temperature decreased by 1.3+/-0.6 degrees C (mean+/-SD) and in the warmed patients 0.5+/-0.4 degrees C (P<0.0001). Preoperative variables and the number of allogeneic units transfused did not differ between the groups. In controls, the blood loss during operation was, with the visual method, 698+/-314 ml, compared with 665+/-292 ml in warmed patients. With the Hb-method, the loss was 662+/-319 and 657+/-348 ml, respectively. With this method, the external loss during the entire hospital stay was, in controls, 1066+/-441 ml and in the warmed group, 1047+/-413 ml. The balance method yielded 1674+/-646 ml and 1507+/-652 ml, respectively. Indices of blood loss did not differ significantly between groups and there was no covariation between those variables and the decrease in core temperature. CONCLUSIONS: Forced air warming did not decrease the blood loss. Methods for determination of blood loss yielded widely differing results.

Quantitative sensory changes in humans after intravenous regional block with mepivacaine.

BACKGROUND AND OBJECTIVES: In previous studies we have demonstrated that after intravenous regional block (IVRA) with dilute mepivacaine, there is a decrease in neurogenic inflammation as well as in post-ischemic hyperemia and steady-state flow, the latter for at least 60 minutes. It is unclear whether these vascular reactions reflect a uniform depression of nerve function in the treated arms. Because the various afferents convey impulses from different types of sensory receptors, we used quantitative sensory testing (QST) to define these effects of IVRA with mepivacaine. METHODS: In 16 volunteers, bilateral blocks were performed by simultaneously injecting mepivacaine in one arm and normal saline in the other in a randomized, double-blind manner. Both arms were kept ischemic for 20 minutes, and the pain was rated on a visual analogue scale. Skin temperature and perception threshold values regarding touch (Abeta-fibers), warmth (C-fibers) and cold (Adelta-fibers), and heat pain (C-fibers) were determined before and repeatedly after the blocks. RESULTS: Ischemic pain did not differ between the arms. After reflow, the thresholds for touch, warmth, and heat pain were unchanged. In the mepivacaine-treated arm, the sensibility to cold was significantly decreased 10 and 30 minutes after the block, though there was a slight decrease in skin temperature. CONCLUSIONS: There was no uniform depression of nerve function after IVRA. The cold receptors and/or their Adelta-fibers were selectively depressed after the block. In conjunction with earlier findings, this suggests that IVRA with mepivacaine can differentially decrease neurogenic inflammation, with little impairment of sensory function.

The effect of hypermetabolism induced by burn trauma on the ethanol-oxidizing capacity of the liver.

OBJECTIVE: To study the rate of elimination of ethanol after a major burn trauma. DESIGN: Prospective, controlled study. SETTING: National burns unit in a Swedish university hospital. PATIENTS AND SUBJECTS: Eight consecutive patients suffering from 18%-72% total burned surface area and nine healthy male control subjects. INTERVENTIONS: The patients received ethanol, 0.35-0.60 g/kg body weight intravenously, during 1 hr. This was repeated daily during the first week postburn. The control subjects received the same amount of ethanol once. MEASUREMENTS AND MAIN RESULTS: Blood samples were drawn at 20- to 30-min intervals during 5 hrs after the start of the infusion. Serum ethanol was determined by headspace gas chromatography. The rate of elimination of ethanol was calculated from the concentration time profile. In the control subjects, the median elimination rate was 0.074 g/kg/hr (range, 0.059-0.083 g/kg/hr). In the patients, it was already 0.138 g/kg/hr (range, 0.111-0.201 g/kg/hr) on the first day; this increased even further over the following 6 days, reaching 0.183 g/kg/hr (range, 0.150-0.218 g/kg/hr) on the seventh day. CONCLUSIONS: Ethanol elimination is augmented postburn. A more effective reoxidation of reduced nicotinamide adenine dinucleotide seems the most likely explanation for the increased rate of ethanol elimination in these hypermetabolic trauma patients. This finding suggests that the oxidative capacity of the liver may be assessed by studying the rate of ethanol elimination in burn victims.

Effects of non-invasive stimulation of acupoints on the cardiovascular system.

OBJECTIVE: To study the effect of two non-invasive methods to stimulate acupoints on the cardiovascular system. DESIGN: Blind randomized-controlled trial. SETTING: An experimental setting in a university-affiliated hospital. INTERVENTIONS: The subjects (24 healthy male volunteers) were randomized to receive either an active stimulation consisting of pressure on acupoints (P), an active stimulation consisting of stroking along the meridians (S) or a control stimulation (C). MAIN OUTCOME MEASURES: Data on skin blood flow, arterial pressure, heart rate and EKG were recorded continuously from 20 min before stimulation to 30 min after. RESULTS: In P group there was a decrease in systolic arterial pressure, diastolic arterial pressure, mean arterial pressure, heart rate and skin blood flow. These changes were significantly different from those in C group and, as regards diastolic pressure and mean pressure, also from those in S group. There were no significant differences between S and C groups. CONCLUSIONS: Pressure on acupoints can significantly influence the cardiovascular system.

Intravenous endotoxin does not increase tissue extravasation of albumin in rats.

BACKGROUND: It is unclear whether activation of the inducible nitric oxide synthase (iNOS) increases or decreases the extravasation of plasma. METHODS: Chloralose anaesthetised male Wistar rats received E. coli lipopolysaccharide (LPS), 3 mg kg-1 i.v., or the corresponding volume of saline, 3 or 5 h before the end of the experiment. Mean arterial pressure (MAP) and heart rate (HR) were recorded. Tissue clearance of radio-labelled albumin, during the last 2 h of each experiment, was determined by a double-isotope method. In separate animals, the serum concentration of nitrite and nitrate was determined, 5 h after LPS or the solvent. MAIN RESULTS: LPS initially decreased MAP and lastingly increased HR. In the 3-h LPS animals (n = 8), tissue plasma clearance was lower in the heart and calf muscle and increased only in diaphragm, compared to corresponding control animals (n = 8). In the 5-h LPS rats, clearance was lowered (n = 8) in the entire gastrointestinal tract and in testes, compared to controls (n = 8). The serum nitrite/nitrate concentration was higher in animals given LPS (n = 6) than in controls (n = 6). CONCLUSION: After LPS, tissue clearance of albumin was not increased in any major tissue, in spite of increased serum levels of NO end products. Apparently, after activation of iNOS, the augmented release of NO is not necessarily associated with increased albumin extravasation.

Intraoperative autotransfusion is associated with modest reduction of allogeneic transfusion in prosthetic hip surgery.

BACKGROUND: The efficacy of intraoperative salvage and washing of wound blood and the predictors of allogeneic red cell transfusions in prosthetic hip surgery are insufficiently known. METHODS: In 96 patients, undergoing primary or revision surgery, salvaged and washed red cells and, if necessary, allogeneic blood were used to keep haematocrit not lower than 33%. The bleeding of red cells during hospital stay was calculated from the red cell balance. The preoperative red cell reserve (mililitres of red cells in excess of a haematocrit of 33%) was estimated and the difference between this volume and the total bleeding of red cells was retrospectively used to classify patients with regard to the need for red cells. Stepwise regression analysis was used to define patient-related variables associated with allogeneic blood transfusion. RESULTS: Preoperative knowledge of the type of operation (primary, revision), the preoperative red cell reserve, and the body mass could predict roughly half of the need for banked blood (r2 = 0.45). Only one-third of the total bleeding of red cells was retransfused. For complete avoidance of allogeneic blood, autotransfusion was most effective in patients with a moderate need (0-4 u). However, 32% of such patients required allogeneic blood. CONCLUSIONS: Autotransfusion has a limited efficacy to decrease the need for allogeneic blood, and other blood-saving methods should be added for this purpose. It is difficult to predict the need for allogeneic blood preoperatively.

Differential effect on vasodilatation and pain after intradermal capsaicin in humans during decay of intravenous regional anesthesia with mepivacaine.

BACKGROUND AND OBJECTIVES: When given intracutaneously, capsaicin can cause burning pain by central propagation in thin afferents, as well as neurogenic vasodilatation, reflecting antidromic conduction in the same fibers. We wanted to test the hypothesis that an intravenous regional block (IVRA) inhibits these two phenomena to a similar degree. METHODS: Sixteen healthy volunteers participated. A bilateral IVRA was performed by simultaneously injecting mepivacaine in one arm and normal saline in the other in a randomized, double-blind manner. Ten minutes after release of the tourniquet, neurogenic inflammation was inflicted in each forearm by intracutaneous capsaicin. Microvascular skin blood flow was measured with a laser Doppler perfusion imager. The area of the flare and the flow therein were measured, taking into account the change in baseline caused by mepivacaine treatment and the postischemic hyperemia. Pain was repeatedly evaluated by visual analog scale. RESULTS: The reactive hyperemia following arterial occlusion was less in the mepivacaine-treated arm 10 minutes after tourniquet release (P=.026). Intracutaneous capsaicin elicited a flare in both arms. The area of the flare was smaller 10 minutes after capsaicin (P=.009) in the mepivacaine-treated arm. There was no difference between the arms concerning the mean blood flow within the flare or in ischemic or capsaicin-induced pain. CONCLUSIONS: Mepivacaine, given as an IVRA, had no effect on the post-IVRA sensory function of thin afferents but differentially decreased the spread of the capsaicin-induced flare.

Combined overdose with verapamil and atenolol: treatment with high doses of adrenergic agonists.

A 55-year-old man was admitted following an overdose of sustained-release verapamil (calcium channel blocker) and ordinary-release atenolol (beta-1 blocker). At admission, there was extreme bradycardia (20-25 beats min-1) and hypotension (systolic arterial pressure 40-50 mm Hg). To counteract the cardiovascular depression, prenalterol, dopamine, dobutamine, isoprenaline, adrenaline and noradrenaline were used. A satisfactory state was obtained with adrenaline, noradrenaline and dopamine infused at high rates. Cardiac output was then more than 101 min-1, with a very low total peripheral resistance. The infusion of the adrenergic agonists could be interrupted on day 3. Prolonged ventilator treatment was necessary but the patient recovered without sequelae. Treatment options for similar cases are outlined.

Mepivacaine as an intravenous regional block interferes with reactive hyperemia and decreases steady-state blood flow.

BACKGROUND AND OBJECTIVES: Local anesthetics block propagation in nerve fibers but may also inhibit inflammation. Inflammatory phenomena such as warmth, reddening, and swelling are intimately connected with blood flow. Our primary aim was to investigate the effect of mepivacaine on cutaneous blood flow in a situation involving hyperemia, but no inflammation, namely, after arterial occlusion. METHODS: The subjects were healthy volunteers (9 men, 7 women). Pain was evaluated by visual analog scale every 5 minutes. A laser Doppler probe was applied on each forearm. After baseline flow measurements during 30 minutes, a bilateral regional intravenous block (Bier block) was performed by injecting mepivacaine (1.4 mg/kg in 40 mL) in one arm and normal saline in the other in a randomized, controlled, double-blind manner. Arterial occlusion was maintained for 20 minutes, and flow was followed for 60 minutes after release of the block. RESULTS: The ischemic pain, though modest, was less (P = .045) in the treated arm. Following release of the cuff, the blood flow had essentially stabilized after 20 minutes. The reactive hyperemia (1-20 minutes) was attenuated in the mepivacaine-treated arm (mean, 68% of placebo, P = .025). In the 21-60-minute period, flow in this arm stabilized at a lower level (mean, 73% of placebo, P = .0013). CONCLUSION: Mepivacaine is a vasoconstrictor of long duration. This has to be taken into account when antiinflammatory effects of mepivacaine are assessed.