EPI Group Research Articles

Felypressin, but Not Epinephrine, Reduces Myocardial Oxygen Tension After an Injection of Dental Local Anesthetic Solution at Routine Doses

The aim of this study was to evaluate the effect of epinephrine (Epi) or felypressin (Fely) contained in dental local anesthetics on myocardial oxygen balance. Male Japanese White tracheotomized rabbits were anesthetized with isoflurane. Three doses of 0.18, 0.36, and 0.72 mL of 2% lidocaine hydrochloride containing 1:80,000 Epi or 3% prilocaine hydrochloride containing Fely 0.03 IU/mL were injected into the rabbit tongue muscle. These doses were equivalent to 2, 4, and 8 of dental local anesthetic cartridges in humans weighing 50 kg by body weight correction, respectively. Heart rate, blood pressure, aortic blood flow, myocardial tissue blood flow, and myocardial tissue oxygen tension were continuously monitored. Data were recorded immediately before and 10, 20, 30, and 60 minutes after the injection. Heart rate decreased in the Fely group. Systolic blood pressure increased in the Epi group, and diastolic blood pressure increased in both groups. Aortic blood flow and myocardial tissue blood flow increased, whereas myocardial tissue oxygen tension did not change in the Epi group. In contrast, aortic blood flow, myocardial tissue blood flow, and myocardial tissue oxygen tension decreased in the Fely group. It is suggested that Fely, but not Epi, decreases myocardial oxygen tension and aggravates myocardial oxygen demand/supply balance even after an injection of dental local anesthetic solution at routine doses.

A Comparison of Three Methods of Pain Control for Posterior Spinal Fusions in Adolescent Idiopathic Scoliosis

Retrospective cohort study. To compare the efficacy of patient-controlled analgesia (PCA) with morphine alone, a single preoperative intrathecal morphine injection and PCA (IT/PCA), and epidural catheter infusion without PCA (EPI) for postoperative pain control after posterior spinal fusion (PSF) and segmental spinal instrumentation (SSI) in adolescent idiopathic scoliosis (AIS). Postoperative pain control after PSF and SSI in AIS can be managed in different ways. EPI provides for a longer period of pain relief but is reliant on the correct placement and maintenance of the catheter in the epidural space. A single preoperative intrathecal morphine injection also provides for long acting analgesia. No direct comparison of these 3 methods of postoperative pain control has been reported. An IRB-approved retrospective chart review was performed at 2 institutions from 1997 to 2005. The medical record was reviewed to determine pain scores after surgery at multiple time periods. The 3 groups were compared using Student t test and chi and significance was defined as P < 0.05. There was no statistical difference in the gender, age, magnitude of curve, or number of levels fused in the IT/PCA (N = 42), PCA (N = 41), or EPI (N = 55) groups. Postoperative pain scores were lowest in the IT/PCA group in the first 8 hours (P < 0.05) but the pain scores in the EPI group were then lower through 24 hours (P < 0.05). Total morphine use (mg/kg) was lower in the IT/PCA group compared with the PCA group at 12 hours and 24 hours (P = 0.0001). Return to solid food ingestion was quickest in the EPI group (2.0 days) followed by the IT/PCA (2.6 days) and PCA alone (3.2 days) (P < 0.002). Respiratory depression and transient neurologic change occurred most frequently in the EPI group (EPI 11/55 pts vs. 1/42 IT/PCA vs. 0/41 PCA P < 0.001). Pruritus was greatest in the epidural group (11/55 P < 0.05). There were no intraoperative somatosensory-evoked potential changes or permanent neurologic injury recorded in any group. An EPI controls postoperative pain for the longest period of time and allows for a quicker return to consumption of solid foods. However, a single preoperative intrathecal morphine injection controls the pain equally for the first 24 hours with less pruritus and with less adverse events thus requiring less nursing and physician intervention after PSF and SSI in AIS. All methods were safe with no neurologic injury recorded.

Lidocaine Concentration in Cerebrospinal Fluid after Epidural Administration

In this study, lidocaine concentrations in cerebrospinal fluid (CSF) at different interspaces were measured with or without preceding spinal anesthesia, 10 min after epidural injection of lidocaine, to investigate the effects of preceding meningeal puncture on CSF concentrations of epidurally administered local anesthetic. Sixty patients scheduled to receive combined spinal-epidural anesthesia were randomly allocated to receive either spinal anesthesia first (group CSEA) or epidural lidocaine first (group Epi). Each group was divided into three subgroups in which the site of epidural cannulation and spinal tap were separated by one, three, or five interspaces (sets I, II, and III, respectively). CSF was collected from the L4-L5 interspace 10 min after 10 ml lidocaine, 1%, was administered epidurally. In group Epi, CSF was collected after epidural administration of lidocaine and before spinal anesthesia. In group CSEA, spinal anesthesia was performed at the L3-L4 interspace after epidural cannulation and epidural lidocaine was administered postoperatively, after which CSF was sampled. Lidocaine concentrations in CSF were significantly higher with increasing proximity of epidural injection site to CSF collection site in both groups. There were no significant differences in CSF lidocaine concentrations between group CSEA and group Epi in set I, although lidocaine concentrations were significantly higher in group CSEA set II and III patients. Lidocaine concentration in CSF was similar with or without preceding meningeal puncture beneath the epidural administration site.

Reduced detection and levels of protective antibodies to hepatitis B vaccine in under 2-year-old HIV positive South African children at a paediatric outpatient clinic

The study evaluated and compared the prevalence of anti-HBs and exposure to hepatitis B virus (HBV) in vaccinated South African babies aged between 5 and 24 months from the Expanded Programme on Immunisation clinic [EPI group] and paediatric outpatient clinic [OPD group], and results were stratified by HIV status. A total of 303 (243 EPI group and 60 OPD group) babies were studied. All sera were tested for anti-HBs, HBsAg and anti-HBc, while IgM anti-HBc and HBV DNA were only tested in samples positive for HBsAg and/or anti-HBc. Overall, there was a gross difference in the prevalence of anti-HBs marker between the EPI and OPD groups. The EPI group demonstrated higher levels of seroconversion (89.3% vs. 81.7%; p = 0.105) and seroprotection rates (86.0% vs. 75.0%; p = 0.038), compared to the OPD babies. When the overall results were stratified by HIV status, seroprotection was 85.7% for the HIV-negatives and 78.1% for the HIV-positives, although this was not statistically significant ( p = 0.125). The seroprotection rates were almost comparable between the HIV-positives (84.3%; n = 51) and the HIV-negatives (86.5%; n = 192) ( p = 0.695) in the EPI group. In contrast, reduced seroprotection rates were observed between the HIV-positives (63.6%; n = 22) and HIV-negatives (81.6%; n = 38) in the OPD group, although this was not statistically significant ( p = 0.123). Interestingly, no HBsAg or anti-HBc marker was detected in the OPD group, compared to total exposure rate of 4.9% (HBsAg carriage was 1.2%) in the EPI group.

Vasopressin and epinephrine in the treatment of cardiac arrest: an experimental study.

BackgroundEpinephrine remains the drug of choice for cardiopulmonary resuscitation. The aim of the present study is to assess whether the combination of vasopressin and epinephrine, given their different mechanisms of action, provides better results than epinephrine alone in cardiopulmonary resuscitation.MethodsVentricular fibrillation was induced in 22 Landrace/Large-White piglets, which were left untreated for 8 minutes before attempted resuscitation with precordial compression, mechanical ventilation and electrical defibrillation. Animals were randomized into 2 groups during cardiopulmonary resuscitation: 11 animals who received saline as placebo (20 ml dilution, bolus) + epinephrine (0.02 mg/kg) (Epi group); and 11 animals who received vasopressin (0.4 IU/kg/20 ml dilution, bolus) + epinephrine (0.02 mg/kg) (Vaso-Epi group). Electrical defibrillation was attempted after 10 minutes of ventricular fibrillation.ResultsTen of 11 animals in the Vaso-Epi group restored spontaneous circulation in comparison to only 4 of 11 in the Epi group (p = 0.02). Aortic diastolic pressure, as well as, coronary perfusion pressure were significantly increased (p < 0.05) during cardiopulmonary resuscitation in the Vaso-Epi group.ConclusionThe administration of vasopressin in combination with epinephrine during cardiopulmonary resuscitation results in a drastic improvement in the hemodynamic parameters necessary for the return of spontaneous circulation.

Epinephrine injection plus hemoclip placement provide better outcomes as compared to epinephrine injection alone in patients with high-risk bleeding gastric ulcer

Introduction: The frequency of gastric ulcer bleeding and the related morbidity and mortality have shown a stable figure for many years despite the use of various methods of endoscopic hemostasis. In high-risk bleeding ulcers local epinephrine injection and/or hemoclip placement to the exposed vessel are established methods for control bleeding and for prevent rebleeding. The aim of the present retrospective study is to compare the efficacy of epinephrine injection (Epi) alone and epinephrine injection +hemoclip placement (Epi+H) in the treatment of high-risk bleeding gastric ulcers. Patients and methods: During a three years period (2004 January-2006 December) 78 patients (mean age: 62ys, 66% male) with high-risk bleeding gastric ulcer were treated endoscopically with local Epi alone (n=62) and with Epi+H (n=16). The Forrest-class distribution (Forrest I/a: 20%, I/b: 23%, I/c: 3%, II/a: 54%), the frequency of comorbidity (89%) and the use of NSAIDs or anticoagulant (80%) did not differed significantly between the treatment groups. Outcome measures as mortality, rebleeding rates, and the need for surgery were compared between the two groups. Results: Mortality rates were higher in patients treated by Epi (19%) as compared to the Epi+H group (6.3%), OR=1.2 95%CI (0.9–1.4), p=0.28. The rate of rebleeding was 28% in the Epi group and 19% in the Epi+H group[p=0.74, OR=1.0 (0.8–1.3)]. Surgery was needed in 35% of pts in the Epi group as compared to 12.5% in the Epi+H group [p=0.12, OR=1.2 (1.0–1.5)]. By multivariate analysis only rebleeding proved to be a significant predictor of mortality [p=0.001, OR=5.4 (2.1–8.7). Conclusion: Although the differences in outcome measures were not statistically significant, the present results supports that the Epi+H may provide favorable outcomes of patients with high-risk bleeding gastric ulcers.

DOES THE USE OF EPINEPHRINE AS AN ADJUNCT INOTROPIC THERAPY IN PRETERM INFANTS REDUCE MORTALITY?

Treatments for hypotensive preterm infants include volume expansion, inotropic agents, and corticosteroids. Common inotropic agents include dopamine, dobutamine, and epinephrine. There are few studies describing the effects and efficacy of inotropes, particularly in terms of survival. This paucity of information led to the hypothesis that in infants ≤ 1,500 g or ≤ 32 weeks9 gestation receiving inotropic support, there will be no difference in mortality when epinephrine is added as an adjunctive inotropic agent. A retrospective chart review of patients admitted to Kosair Children9s Hospital NICU from December 2002 to December 2005 was performed. Preterm infants ≤ 1,500 g or ≤ 32 weeks gestation who received inotropic support were included. Patients were excluded for life-threatening congenital defects. Those infants who received epinephrine (epi) as an adjunctive inotropic agent were compared with infants who did not receive epinephrine (no-epi). Admission demographic data, BP, ABGs, and UOP were recorded. SNAPPE-II and CRIB-II scores were calculated. BP, HR, and ABGs were recorded prior to initiation and during inotropic support. The primary outcome variable was death. Data were analyzed with SPSS for Windows (V. 14; SPSS Inc). Eighty-eight infants were considered for analysis. There was a significant difference in BW and EGA between the groups; however, there was no difference in admitting diagnoses, BP, ABG, or UOP. There was a trend toward higher predicted mortality in the epi group. Prior to intervention, there was no difference in BP, HR, or ABGs. With intervention, the epi group demonstrated a higher maximum HR (p

Effects of sympathetic stimulation during cooling on hypothermic as well as posthypothermic hemodynamic function

This experimental study was performed to explore hemodynamic effects of a moderate dose epinephrine (Epi) during hypothermia and to test the hypothesis whether sympathetic stimulation during cooling affects myocardial function following rewarming. Two groups of male Wistar rats (each, n=7) were cooled to 15 degrees C, maintained at this temperature for 1 h, and then rewarmed. Group 1 received 1 microg/min Epi, i.v., for 1 h during cooling to 28 degrees C, a dose known to elevate cardiac output (CO) by approximately 25% at 37 degrees C. Group 2 served a saline solution control. At 37 degrees C, Epi infusion elevated CO, left ventricular systolic pressure, maximum rate of left ventricle pressure rise, and mean arterial pressure. During cooling to 28 degrees C, these variables, with the exception of mean arterial pressure, decreased in parallel to those in the saline solution group. In contrast, in the Epi group, mean arterial pressure remained increased and total peripheral resistance was significantly elevated at 28 degrees C. Compared with corresponding prehypothermic values, most hemodynamic variables were lowered after 1 h at 15 degrees C in both groups (except for stroke volume). After rewarming, alterations in hemodynamic variables in the Epi-treated group were more prominent than in saline solution controls. Thus, before cooling, continuous Epi infusion predominantly stimulates myocardial mechanical function, materialized as elevation of CO, left ventricular systolic pressure, and maximum rate of left ventricle pressure rise. Cooling, on the other hand, apparently eradicates central hemodynamic effects of Epi and during stable hypothermia, elevation of peripheral vascular vasopressor effects seem to take over. In contrast to temperature-matched, non-Epi stimulated control rats, a significant depression of myocardial mechanical function occurs during rewarming following a moderate sympathetic stimulus during initial cooling.

A prospective, randomized, blinded comparison between continuous thoracic paravertebral and epidural infusion of 0.2% ropivacaine after lung resection surgery

The aim of this prospective, randomized, blinded study was to compare analgesic efficacy of continuous paravertebral and epidural analgesia for post-thoracotomy pain. Forty-two ASA physical status II-III patients undergoing lung resection surgery were randomly allocated to receive post-thoracotomy analgesia with either a thoracic epidural (group EPI, n = 21) or paravertebral (group PVB, n = 21) infusion of 0.2% ropivacaine (infusion rate: 5-10 mL h-1). The degree of pain at rest and during coughing, haemodynamic variables and blood gas analysis were recorded every 12 h for the first 48 h. The area under the curve of the visual analogue pain score during coughing over time was 192 (60-444) cm h-1 in group EPI and 228 (72-456) cm h-1 in group PVB (P = 0.29). Rescue morphine analgesia was required in four patients of group EPI (19%) and five patients of group PVB (23%) (P = 0.99). The PaO2/FiO2 ratio reduced significantly from baseline values in both groups without between-group differences. The median (range) percentage reduction of systolic arterial pressure from baseline was -9 (0 to -9)% in group PVB and -17 (0 to -38)% in group EPI (P = 0.02); while clinically relevant hypotension (systolic arterial pressure decrease >30% of baseline) was observed in four patients of group EPI only (19%) (P = 0.04). Patient satisfaction with the analgesia technique was 8.5 (8-9.8) cm in group EPI and 9 (7.5-10) cm in group PVB (P = 0.65). Continuous thoracic paravertebral analgesia is as effective as epidural blockade in controlling post-thoracotomy pain, but is associated with less haemodynamic effects.

Effects of Insulin on the Resuscitation by Epinephrine for Bupivacaine-Induced Cardiovascular Depression in Dogs

Background: Because of the difficulty of resuscitation caused by bupivacaine-induced cardiotoxicity, the choice of resuscitation medication is still unclear. We investigated whether insulin can improve outcomes of resuscitation by epinephrine from bupivacaine-induced cardiovascular collapse. Methods: Twenty-four mongrel dogs were randomly allocated to one of the two groups: an EPI group (n = 12), and an EPI + RI group (n = 12). Sixty minutes after induction of general anesthesia, baseline measurement of hemodynamic parameters and arterial blood gas tension was performed. Bupivacaine infusion was started at a rate of 0.5 mg/kg/min and kept until mean arterial blood pressure fell below 40 mmHg and heart rate 40 beats per minute. At this point, bupivacaine infusion was stopped and resuscitation was started, with epinephrine in EPI group and epinephrine combined with regular insulin in EPI + RI group. Results: Bupivacaine infusion caused significant decreases in mean arterial blood pressure, heart rate, cardiac output, and systemic vascular resistance and increases in mean pulmonary blood pressure, pulmonary capillary wedge pressure, pulmonary vascular resistance, and central venous pressure. The recovery rate of EPI + RI group (8/12) was higher than that of EPI group (2/12). Conclusions: Combined administration of epinephrine and regular insulin improves outcomes of resuscitation of bupivacaine- induced cardiovascular collapse. Therefore, we believe that prompt administration of insulin should be strongly considered in case of bupivacaine-induced cardiotoxicity.

Effects of Intravenous Patient-Controlled Analgesia With Morphine, Continuous Epidural Analgesia, and Continuous Femoral Nerve Sheath Block on Rehabilitation After Unilateral Total-Hip Arthroplasty

Regional analgesic techniques allow better postoperative rehabilitation and shorter hospital stay after major knee surgery. The authors tested the hypothesis that similar results could be obtained after total-hip arthroplasty. Forty-five patients scheduled for THA under general anesthesia were randomly divided into 3 groups. Postoperative analgesia was provided during the first 48 hours, with intravenous patient-controlled analgesia (IV PCA) induced by morphine (dose, 1.5 mg; lockout interval, 8 min) in group IV, continuous femoral nerve sheath block in group FNB, and continuous epidural analgesia in group EPI. The day after surgery, the 3 groups started identical physical therapy regimens. Pain scores at rest and on movement, supplemental analgesia, side effects, daily degree of maximal hip flexion and abduction, day of first walk, and duration of hospital stay were recorded. Population data, quality of pain relief, postoperative hip rehabilitation, and duration of hospital stay were comparable in the 3 groups. When compared with the two other techniques, continuous FNB was associated with a lower incidence of side effects (no nausea/vomiting, urinary retention, arterial hypotension, or catheter problem during the first 48 hours in 20%, 60%, and 13% of patients in groups IV, FNB, and EPI, respectively). This study suggests that IV PCA with morphine, continuous FNB, and continuous epidural analgesia provide similar pain relief and allow comparable hip rehabilitation and duration of hospital stay after total-hip arthroplasty (THA). As continuous FNB is associated with less side effects, it appears to offer the best option of the three.

The use of dexrazoxane as a cardioprotectant in patients receiving epirubicin-based chemotherapy for metastatic breast cancer

640 Background: The clinical utility of anthracyclines is limited by dose-related cardiotoxicity. Epirubicin, the 4’-epimer of doxorubicin, is reportedly less cardiotoxic than doxorubicin when administered at equimolar doses. However, the existence of cumulative dose-related cardiotoxicity of epirubucin is now clearly established. Dexrazoxane, a cardioprotective agent, has been shown to reduce the risk of anthracycline-associated cardiotoxicity. Methods: This multicenter, randomized, controlled study enrolled adult female subjects with advanced/metastatic breast cancer who had received prior anthracycline-based chemotherapy. Patients were randomized to receive anthracycline-based chemotherapy with or without dexrazoxane, (dose ratio for dexrazoxane:epirubicin = 10:1). Cardiac assessments were reviewed by an independent Adjudication Committee blinded to treatment arm. A reduction in left ventricular ejection fraction (LVEF) 10% measured by MUGA scan or 15% measured by echocardiography, or a reduction in absolute LVEF to a value below 45% was deemed to constitute a cardiac event. A sub-group analysis of patients treated with epirubicin alone (EPI, n=28) or epirubicin + dexrazoxane (DEX+EPI, n=29) was performed. Results: Median total cumulative doses of epirubicin (including pre-study exposure) were 742mg/M2 (range 375–1200) and 869mg/M2 (419–1188) respectively. Significantly fewer DEX+EPI patients developed a cardiac event (14%, 95% CI:4–32%) compared to the EPI group (43%, 95%CI:24–63%) (p=0.015, Pearson’s Chi Square test). Three patients in the EPI group developed congestive heart failure, (two NYHA grade III and one grade IV, total cumulative EPI doses 991, 952 and 610mg/M2 respectively). There were no cases of CHF in the DEX+EPI group, (p=NS). There was no significant difference in overall tumor response rates between the two groups; DEX+EPI 48% (95% CI 30–67%) vs EPI 25% (95%CI 11–43%), (p=0.054). Conclusions: This study confirms the cardiotoxicity of cumulative epirubicin-based chemotherapy. Dexrazoxane significantly reduces the risk of epirubicin-induced cardiotoxicity, both clinical and sub-clinical, without compromising tumor response. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Chiron Biopharmaceuticals Chiron Biopharmaceuticals

Effect of pre-emptive ketamine on sensory changes and postoperative pain after thoracotomy: comparison of epidural and intramuscular routes

In this study we have evaluated the efficacy of ketamine via i.m. and epidural routes for the control of post-thoracotomy pain. The study was randomized, double blinded and placebo controlled. With the approval of the Faculty Ethics Committee, 60 patients undergoing elective thoracotomy were randomized into three equal groups. Group IM had i.m. ketamine 1 mg kg(-1) in 2 ml plus epidural normal saline; Group EPI had epidural ketamine 1 mg kg(-1) in 10 ml plus i.m. normal saline; Group C had epidural normal saline 10 ml plus i.m. normal saline 10 ml. Anaesthesia was standardized. Postoperative analgesia was maintained with epidural patient-controlled analgesia using bupivacaine and morphine. Visual analogue scale values and analgesic consumption were evaluated at 2, 4, 6, 8, 10, 12, 24 and 48 h after surgery. The areas of allodynia, pin-prick hyperalgesia and pressure hyperalgesia were measured at 48 h, and days 15 and 30 in all groups. Intraoperative fentanyl requirement was significantly lower in Group EPI than Group C. The morphine and bupivacaine requirements were significantly lower in Group EPI than the other two groups in the postoperative period. There was reduced pin-prick hyperalgesia and touch allodynia in the EPI group. There were no side-effects attributable to ketamine. The results of the present study demonstrate that pre-emptive epidural ketamine is effective in reducing intra- and postoperative analgesic requirements, hyperalgesia and touch allodynia.

Catheter ablation of ventricular fibrillation in rabbit ventricles treated with beta-blockers.

A therapeutic implication of the focal-source hypothesis of ventricular fibrillation (VF) is that VF can be terminated by focal ablation. We hypothesize that beta-adrenergic receptor blockade converts multiple-wavelet VF to focal-source VF and that this focal source is located near the papillary muscle (PM). We used optical mapping techniques to study the effects of propranolol (0.3 mg/L) on VF dynamics in Langendorff-perfused rabbit hearts. The left ventricular (LV) anterior wall was mapped and optical action potential duration restitution (APDR) was determined at 25 epicardial sites. We performed ablation during VF of the left anterior PM in hearts with (N=6) or without (N=6) cytochalasin infusion, the LV lateral epicardium (Epi group, N=3), and the LV endocardium (Endo group, N=3). The PM was also ablated in 3 hearts without propranolol (control group). Propranolol converted multiple-wavelet VF to slow VF with reentry localized to the PM. Propranolol decreased the maximal slope of the APDR curve (P<0.001) as well as its spatial heterogeneity (P<0.01) and conduction velocity (P=0.01) while increasing the VF cycle length (P<0.001). PM ablation terminated VF during propropranolol infusion with (6 of 6, 100%) or without (4 of 6, 67%) cytochalasin D and significantly reduced inducibility. VF did not terminate in the Epi, Endo, and control groups (P<0.001). Propranolol flattens the APDR curve and reduces conduction velocity, converting multiple-wavelet VF into VF with a focal source anchored to the PM. Ablation of this focal source may terminate VF.

Use of a charged lidocaine derivative, tonicaine, for prolonged infiltration anesthesia

Background and Objectives: We tested the hypothesis that the duration of cutaneous anesthesia elicited by the permanently charged compound N-phenylethyl lidocaine (tonicaine) would be longer than that elicited by its parent structure, lidocaine, and that it would be less affected by epinephrine (epi), after subcutaneous injection in rats, as a model for infiltration anesthesia. Methods: Subcutaneous injections were performed on the shaved dorsal skin of rats with either tonicaine or lidocaine (0.1% or 0.5%, n = 8 in each group) with and without epi (1:200,000). Inhibition of the cutaneous trunci muscle reflex was quantitatively evaluated by a blinded observer by the number of times pinpricks failed to elicit the nocifensive motor response out of a total of 6 pinpricks applied to the injected area. Results: Duration of complete nociceptive blockade in the 0.5% tonicaine and lidocaine groups was 619 [plusmn] 47 and 58 [plusmn] 2 minutes, respectively; duration of full recovery in these groups was 1,106 [plusmn] 19 and 86 [plusmn] 3 minutes, respectively. Epi increased the duration of complete block in the 0.5% tonicaine and lidocaine groups to 750 [plusmn] 13 and 97 [plusmn] 11 minutes, respectively, and the duration of full recovery to 1,185 [plusmn] 13 and 172 [plusmn] 6 minutes, respectively. Skin toxicity was seen only in the 0.5% tonicaine with epi group (3 of 8 rats). Conclusions: Tonicaine is a substantially longer lasting local anesthetic with a delayed onset of action compared with lidocaine and may be useful in situations where long duration of infiltration block is desirable. Reg Anesth Pain Med 2002;27:173-179.

Mind the model: effect of instrumentation on inducibility of atrial fibrillation in a sheep model.

Atrial electrical remodeling, shortening of the atrial effective refractory period (AERP) underlying atrial fibrillation (AF) has been described in different animal models. However, there remains some controversy regarding the time course of this electrical remodeling and the need for secondary factors in the development of AF. We investigated the effect of instrumentation on the inducibility of AF. We hypothesized that epicardial instrumentation could be a confounding factor that accelerates the development of AF. Thirty sheep were rapidly atrially paced at 600 beats/min for 15 weeks: 15 were endocardially instrumented and paced (endo), and 15 were both endocardially and epicardially instrumented. Six of these animals were endocardially paced (sham) and 9 were epicardially paced (epi). The underlying rhythm was determined at regular intervals, and electrophysiologic study was performed. AF developed significantly faster in the epi group. After 3 weeks of pacing, the cumulative incidence of sustained AF (>1 hour) already was 70% in this group versus only 14% and 20% in the endo and sham groups, respectively. After 15 weeks of pacing, this difference was no longer evident. Baseline AERP and minimal AERP, reached before the development of AF, were not significantly different in the three groups. Epicardial instrumentation (epi and sham) increased baseline left and right atrial pressures, but only epicardial stimulation (epi) led to early development of AF. In this sheep model of AF, the experimental setup is a major determinant of the inducibility of AF. Not epicardial instrumentation per se but epicardial stimulation accelerated the development of AF. Different animal models

Cognitive Performance of Patients with Epilepsy and Calcified Neurocysticercotic Lesions: A Case–Control Study

Neuropsychological tests were applied to 20 patients with focal epilepsy related to calcified neurocysticercosis (NCC) (mean: three lesions/patient; NCC group), 22 patients with focal epilepsy without NCC (EPI group), and 29 healthy controls matched for age, sex, and educational level. The EPI and NCC groups were matched for age at onset of epilepsy, epilepsy duration, frequency of attacks, seizure semiology, interictal EEG findings, and antiepileptic drugs used. There were no differences in the digit span, word span, calculus, and Mini-Mental State examination among the three groups studied. The NCC and EPI groups showed lower scores than controls in immediate and delayed verbal memory, famous faces test, spatial recognition span, abstractions and judgment, and visuoconstructional abilities. The EPI group, but not the NCC group, also had lower scores in a praxis tests. There were no differences between the NCC and EPI groups in any of the tests applied ( P > 15), except for the spatial recognition span, which was lower in the former. Cognitive impairment is a prevalent neuropsychological feature of patients with epilepsy and NCC.

Long-term follow up of traumatic multiple rib fractures

We investigated the prognosis of patients with multiple rib fractures for 2 years after discharge from the hospital, and whether the pain control management during the initial respiratory care influence the respiratory function or neurological findings. The ethical committee in Fukushima Medical University approved this study. 221 patients with chest blunt trauma were admitted in our hospital from 1990 to 1996. We found 61 cases that had more than 4 rib fractures with or without pulmonary contusion. The subjects that were 51 patients who had traffic or some other accidents can be followed by phone and investigated. Forty-one cases were received mechanical ventilation for from 5 to 18 days. All of 51 cases were administrated oxygen and drugs that controlled the chest pain. Nineteen of 51 patients (EPI group) were undergone the epidural anesthesia with xylocain for the first 7 days (5–9 days). The other patients (non-EPI group) were administrated narcotics or non-steroid anti-inflammatory agents. Measurements were arterial blood gasses, respiratory functions, chest X-ray, physical and neurological findings. The subjects were 48 patients who had traffic or some other accidents. Respiratory care was required in 20 cases for 5 to 18 days. PaO2, %VC, PEFR (peak expiratory flow rate) were gradually increased after discharge. The improvement was not associated between both of pain controls. Chest deformities were seen in 12 of 51 cases. Râle sound was audible in three cases. Neurological findings (spontaneous pain, tenderness, hypersthesia, sensory disturbance) were found less frequent in patients who were treated under epidural anesthesia. The epidural anesthesia sometimes induced hypotension, however, fluid resuscitation improved. The epidural anesthesia was better than the other narcotics or anti-inflammatory drugs from the points of neurological prognosis. Sensory disturbance is not associated with chest deformities but pain control. Epidural anesthesia was one of the useful pain management to avoid neurological complications after long-term of multiple rib fractures of chest trauma.

Epidural sufentanil during paediatric cardiac surgery: effects on metabolic response and postoperative outcome

The metabolic and neuroendocrine effects of caudal epidural analgesia were studied during paediatric cardiac surgery. Combined epidural and general anaesthesia (EPI group; n=12) was compared with deep opioid anaesthesia (DOA group; n=12). During anaesthesia and surgery, haemodynamic stability was similar in the two groups. There was no significant difference between groups concerning the metabolic response to surgery but circulating catecholamines were significantly lower in the EPI group during and after surgery. Perioperative release of IL-6 was higher in the EPI group possibly reflecting a longer aortic clamp time. Incidence of postoperative life-threatening dysrhythmias was very low in the two groups. No significant reduction of postoperative mechanical ventilation, intensive care unit or hospital stays was reported with epidural analgesia. The incidence of postoperative infections was higher than expected in the two groups because of the poor properative clinical status of most of the children included in the study.

109. N100 and P300 ERP abnormalities in schizophrenia and epilepsy

The occurrence of schizophrenia-like symptoms in patients with epilepsy has led to speculations regarding the commonalities between the two disorders, particularly with regard to temporal lobe abnormalities. The N1 and P300 components of the auditory event-related potential (ERP) elicited by infrequently occurring task-related stimuli are commonly reduced in patients with schizophrenia. Whether these reductions are related to the pathophysiological processes specific to schizophrenia or to psychotic symptoms more generally was addressed by comparing patients with schizophrenia (SZ, n = 25), epilepsy with interictal schizophrenia (SZ-EPI, n = 7), epilepsy without psychotic symptoms (EPI, n = 16), and normal controls (n = 32). ERPs were elicited using visual and auditory oddball paradigms involving a task (effortful) and an auditory non-task (automatic) paradigm. SZ-EPI and EPI patients had mixed foci, including right and left, frontal and temporal, unlocalized, partial, and generalized primary epilepsy. Auditory P300 at Pz was reduced in SZ and SZ-EPI, but not in the EPI group as a whole. In contrast, N1 was only reduced in SZ. While automatic P300 was not lateralized in the controls of schizophrenics (SZ and SZ-EPI), it was more reduced at left compared to right temporal lobe sites regardless of epileptic focus in the EPI group. Visual P300 was not reduced in any clinical group. These data suggest that reductions in N1 are specific to the pathophysiological process of schizophrenia, while P300 reduction is more generally associated with psychosis, whether it occurs in schizophrenia or epilepsy.