Pedro Paulo Tanaka

Comparative study of 0.5% bupivacaine versus 0.5% bupivacaine enantiomeric mixture (S75-R25) in epidural anesthesia for orthopedic surgery

BACKGROUND AND OBJECTIVES With the objective of finding a safer drug than racemic bupivacaine, several animal studies were performed with its enantiomers. This study aimed at evaluating the efficacy of 0.5% bupivacaine enantiomeric mixture (S75-R25) as compared to 0.5% bupivacaine in lumbar epidural anesthesia for lower limb orthopedic surgery. METHODS Participated in this randomized double-blind study 38 adult patients, aged 17 to 69 years, physical status ASA I and II submitted to lower limb orthopedic surgery, who were distributed in two groups: Group B - 30 ml of 0.5% bupivacaine and Group BEM - 30 ml of 0.5% bupivacaine enantiomeric mixture (S75-R25). Sensory and motor block characteristics were investigated, in addition to the incidence of side effects. RESULTS There have been significant weight differences in group BEM. Hemodynamic parameters were similar in both groups. There were no differences in time to reach Bromage score and peak block height. Also time to total motor block regression was similar between groups. There has been a significant difference in Bromage 2 score between groups, which was higher in group BEM. CONCLUSIONS Adequate sensory and motor block for surgery was achieved in both groups with few side effects, suggesting that both solutions are safe in lumbar epidural anesthesia for orthopedic surgery.

Comparative-Effectiveness of Simulation-Based Deliberate Practice Versus Self-Guided Practice on Resident Anesthesiologists' Acquisition of Ultrasound-Guided Regional Anesthesia Skills.

Background and Objectives Simulation-based education strategies to teach regional anesthesia have been described, but their efficacy largely has been assumed. We designed this study to determine whether residents trained using the simulation-based strategy of deliberate practice show greater improvement of ultrasound-guided regional anesthesia (UGRA) skills than residents trained using self-guided practice in simulation. Methods Anesthesiology residents new to UGRA were randomized to participate in either simulation-based deliberate practice (intervention) or self-guided practice (control). Participants were recorded and assessed while performing simulated peripheral nerve blocks at baseline, immediately after the experimental condition, and 3 months after enrollment. Subject performance was scored from video by 2 blinded reviewers using a composite tool. The amount of time each participant spent in deliberate or self-guided practice was recorded. Results Twenty-eight participants completed the study. Both groups showed within-group improvement from baseline scores immediately after the curriculum and 3 months following study enrollment. There was no difference between groups in changed composite scores immediately after the curriculum (P = 0.461) and 3 months following study enrollment (P = 0.927) from baseline. The average time in minutes that subjects spent in simulation practice was 6.8 minutes for the control group compared with 48.5 minutes for the intervention group (P < 0.001). Conclusions In this comparative effectiveness study, there was no difference in acquisition and retention of skills in UGRA for novice residents taught by either simulation-based deliberate practice or self-guided practice. Both methods increased skill from baseline; however, self-guided practice required less time and faculty resources.

Preparation, characterization and in vitro evaluation of 50% enantiomeric excess bupivacaine (S75-R25)-loaded microspheres.

BACKGROUND AND OBJECTIVES: Microspheres can be used as a controlled delivery system to prolong the duration of action of local anesthetics. The objective of this study was the preparation, characterization and analysis of the in vitro release of 50% enantiomeric excess bupivacaine (S75-R25)-loaded microspheres. METHODS: Microspheres were prepared using the copolymer of polylactide-co-glycolic acid by the spray-dryed method. RESULTS: Characterization of microspheres regarding their size and content were similar to the theoretical values. The in vitro release demonstrated a biphasic pattern. CONCLUSIONS: Manufacturing of 50% enantiomeric excess bupivacaine-loaded microspheres by the spray-dryed method with results similar to bupivacaine-loaded microspheres can be done.

Levobupivacaine 0.5%, 50% enantiomeric excess bupivacaine and racemic bupivacaine in epidural anesthesia for lower abdominal procedures. Comparative study

JUSTIFICATIVA Y OBJETIVOS: Con la finalidad de encontrar un anestesico local mas seguro que la bupivacaina, varios estudios en animales fueron realizados con sus isomeros. Este estudio tuvo como objetivo evaluar la eficacia de la bupivacaina en exceso enantiomerico del 50%, comparada a la levobupivacaina y a la bupivacaina racemica, en la anestesia peridural en pacientes sometidos a la cirugia de abdomen inferior, por el periodo de una hora despues de la inyeccion de las soluciones. METODO: Despues de la aprobacion por el Comite de Etica en Pesquisa, participaron de este estudio, eventual y doblemente encubierto, 87 pacientes con edad entre 18 y 65 anos, estado fisico ASA I y II sometidos a cirugia del abdomen inferior. Fueron distribuidos en tres grupos que fraccionadamente recibieron solucion conteniendo 27 mL (incluyendo la dosis-test) de anestesico local con adrenalina (1:200.000) y fentanil (100 µg). El grupo I recibio solucion de levobupivacaina a 0,5%, el grupo II recibio solucion de bupivacaina en exceso enantiomerico del 50% a 0,5% y el grupo III recibio solucion de bupivacaina a 0,5%. Los pacientes fueron monitorizados por medio de oximetro de pulso, cardioscopio y presion arterial no invasiva. Fueron investigadas las caracteristicas motoras y sensitivas del bloqueo anestesico, bien como la incidencia de efectos colaterales. Los frascos de anestesico local fueron preparados sin identificacion, numerados y solamente al final del estudio la lista de distribucion eventual fue abierta. RESULTADOS: No se observaron diferencias significativas con relacion a la altura y estado fisico. Diferencia demografica significativa fue encontrada con relacion a la edad en el grupo I. Los parametros hemodinamicos fueron semejantes entre los grupos. Hubo una diferencia significativa con relacion a la intensidad del bloqueo motor relatado entre los grupos estudiados (menor intensidad en el grupo I comparada a los grupos II y III). CONCLUSIONES: Fue observado un adecuado bloqueo motor y sensitivo para la realizacion de la cirugia en los grupos estudiados con pocos efectos colaterales, sugiriendo que las soluciones son eficaces en la anestesia peridural para cirugia de abdomen inferior. La levobupivacaina presento menor bloqueo motor que los otros dos grupos.

The effect of desflurane versus propofol anesthesia on postoperative delirium in elderly obese patients undergoing total knee replacement: A randomized, controlled, double-blinded clinical trial

STUDY OBJECTIVE The goal of this study was to investigate the incidence of delirium, wake-up times and early post-operative cognitive decline in one hundred obese elderly patients undergoing total knee arthroplasty. DESIGN Prospective randomized trial. SETTINGS Operating room, postoperative recovery area, hospital wards. PATIENTS 100 obese patients (ASA II and III) undergoing primary total knee replacement under general anesthesia with a femoral nerve block catheter. INTERVENTION Patients were prospectively randomized to maintenance anesthesia with either propofol or desflurane. MEASUREMENTS The primary endpoint assessed by a blinded investigator was delirium as measured by the Confusion Assessment Method. Secondary endpoints were wake-up times and a battery of six different tests of cognitive function. MAIN RESULTS Four of the 100 patients that gave informed consent withdrew from the study. Of the remaining 96 patients, 6 patients did not complete full CAM testing. Preoperative pain scores, durations of surgery and anesthesia, and amount of intraoperative fentanyl were not different between groups. One patient in the propofol group developed delirium compared to zero in desflurane. One patient in desflurane group developed a confused state not characterized as delirium. Fifty percent of the patients exhibited a 20% decrease in the results of at least one cognitive test on the first 2days after surgery, with no difference between groups. There were no differences in the time to emergence from anesthesia, incidence of postoperative nausea and vomiting, and length of postanesthesia care unit (PACU) stay between the two groups. CONCLUSIONS In conclusion we found a low incidence of delirium but significant cognitive decline in the first 48h after surgery. In this relatively small sample size of a hundred patients there was no difference in the incidence of postoperative delirium, early cognitive outcomes, or wake up times between the desflurane or propofol group.

Control of pain trough epidural block and incidence of cardiac dysrhythmias in postoperative period of thoracic and major abdominal surgical procedures: a comparative study

BACKGROUND AND OBJECTIVES Upper abdomen and thorax surgeries cause intense pain. Some of postoperative pain main complications are cardiocirculatory complications. The objective of this study was to test the hypothesis that postoperative analgesia with employment of local anesthetics plus spinal opioids may reduce the incidence of cardiovascular complications in postoperative period of patients in these conditions, comparing with classical methods of postoperative analgesia, opioids and NSAIDs, administered upon patients demand. METHOD Eighty adult patients, ASA I and II, without ECG alterations, were allocated into two groups of 40: Group A, patients under general anesthesia with propofol, cisatracurium and isoflurane, associated with epidural anesthesia with catheter and control of postoperative analgesia with bupivacaine and epidural morphine; and Group B, patients under general anesthesia with the same drugs and doses of A, plus postoperative analgesia carried out with NSAIDs and intravenous morphine at the end of surgery and in regular intervals. In both groups Holter was applied for 24 hours. Pain evaluation was carried out through visual analog scale. RESULTS In pain evaluation, an evident predominance of 0 score (p<0.001) was observed in Group A and there was also reduction of blood pressure levels in postoperative period in a more accentuated way. Ventricular and supraventricular dysrhythmias were five times more frequent in Group B (p=0.00001), in which a tendency to a higher frequency of ventricular extrasystoles in age>50 years (22.2% versus 0.0%. p=0.26) was also detected. No significative difference of heart rate among groups (p>0.05) was observed. CONCLUSIONS The best quality of analgesia in postoperative period, carried out in Group A, reduced the incidence of cardiovascular complications.

Controle da dor por bloqueio peridural e incidência de disritmias cardíacas no pós-operatório de procedimentos cirúrgicos torácicos e abdominais altos: estudo comparativo

JUSTIFICATIVA E OBJETIVOS: Operacoes no abdome superior e torax provocam intensa dor. Entre as principais complicacoes da dor pos-operatoria estao as complicacoes cardiocirculatorias. O objetivo deste trabalho foi testar a hipotese de que a analgesia pos-operatoria com o emprego de anestesicos locais mais opioides espinhais pode reduzir a incidencia de complicacoes cardiovasculares no pos-operatorio de pacientes nessas condicoes, comparando-se a metodos classicos de analgesia pos-operatoria, opioides e AINES, administrados segundo demanda do paciente. METODO: Oitenta pacientes adultos ASA I e II, sem alteracoes ECG, alocados em dois grupos de 40: Grupo A, sob anestesia geral com propofol, cisatracurio e isoflurano, associado a anestesia peridural, com cateter e controle da analgesia pos-operatoria com bupivacaina e morfina peridural; e Grupo B, sob anestesia geral com as mesmas drogas e doses que o Grupo A, mais analgesia pos-operatoria realizada com AINES e morfina endovenosa no final da operacao e em intervalos regulares. Em ambos foi aplicado Holter por 24 horas. A avaliacao da dor foi realizada pela escala analogica visual. RESULTADOS: Na avaliacao da dor observou-se no Grupo A evidente predominio do escore 0 (p 50 anos (22,2% versus 0,0%. p = 0,26). Nao se observou diferenca significativa da frequencia cardiaca entre os grupos (p > 0,05). CONCLUSOES: A melhor qualidade da analgesia no pos-operatorio, realizada nos pacientes do Grupo A, reduziu a incidencia de complicacoes cardiovasculares

Assessing the use of 50% enantiomeric excess bupivacaine-loaded microspheres after sciatic nerve block in rats

BACKGROUND AND OBJECTIVES To achieve better therapeutic benefits of local anesthetics in the control of postoperative pain through controlled-release carrier. The objective of this study was to compare the characteristics of sensory and motor blockade between microspheres without local anesthetic: racemic bupivacaine-loaded microspheres; 50% enantiomeric excess bupivacaine-loaded microspheres; and free 50% enantiomeric excess bupivacaine. METHODS Wistar rats were distributed into four groups: A (Microsphere); B (S50-R50 bupivacaine-loaded microsphere); C (50% enantiomeric excess bupivacaine-loaded microsphere); and D (50% enantiomeric excess bupivacaine). Inhalation anesthesia was performed before the sciatic nerve block (2% halothane and 100% O(2)). Sensorial blockade was measured by the time required for each rat to withdraw its paw from a hot plate at 56°C (positive>4 sec). Motor blockade was measured by the time between drug injection until recovery of a motor score of 2 on the established criterion. RESULTS The sensory response was significantly more frequent in groups B, C, and D than in group A (p<0.001). There were no statistically significant differences in the response to the sensory test in groups B, C, and D (p>0.05). The response to the motor test was also significantly more frequent in groups B, C, and D than in group A (p=0.02). A tendency to greater positivity in the motor test was more frequently found in groups B and D than in group C (p=0.10). CONCLUSIONS Controlled-release of 50% enantiomeric excess bupivacaine-loaded microspheres showed similar results regarding analgesia and less motor blockade when compared to other anesthetic formulations.

The stanford anesthesia faculty teaching scholars program: summary of faculty development, projects, and outcomes.

BACKGROUND The Stanford Anesthesia Teaching Scholars Program was launched in 2007 to further pedagogic training of faculty and improve residency education. OBJECTIVES The goals of this article are to describe the program intervention and improvements made based on participant feedback, summarize the characteristics of the faculty enrolled and projects undertaken, and report on program outcomes tracked to date. INTERVENTION THE TEACHING SCHOLARS PROGRAM HOUSED WITHIN THE DEPARTMENT OF ANESTHESIA SUPPORTS FACULTY IN THESE AREAS: (1) attending education-related meetings; (2) engaging in a monthly seminar on core topics paired with independent study reading; and (3) undertaking a project to improve resident education. Structured interviews with all graduates (n  =  19; 47% women) were conducted using a pilot-tested questionnaire. RESULTS A total of 15 of 19 Scholars (79%) were instructors/assistant professors. Sixteen Scholars (84%) attended an off-site education meeting. The Scholars pursued a variety of projects, including curriculum (53%), teaching (26%), administration (11%), assessment (5%), and advising/mentoring (5%). Projects were fully completed by 13 of 19 participants (68%), and 12 of 19 projects (63%) are currently integrated into the residency. Completed projects were published/presented at conferences by 4 of 13 participants (31%), and education grants were received by 3 of 19 participants (16%). CONCLUSIONS This is the first description of a faculty development (education) program in an anesthesiology department. The program has been well accepted by participants and resulted in increased educational products, some of which have become a permanent part of the residency curriculum. This educational innovation can be replicated in other departments of anesthesiology provided that funding is available for faculty time and meeting expenses.

Isquemia do nervo óptico após intervenção cirúrgica na coluna vertebral: relato de caso

JUSTIFICATIVA Y OBJETIVOS: La perdida de la vision es una de las complicaciones poco comunes que pueden ocurrir en el posoperatorio de operaciones no oftalmologicas, y su incidencia puede ser constatada por el creciente numero de estudios disponibles en la literatura internacional. El objetivo de este relato fue el de mostrar un caso de anopsia despues de cirugia de columna vertebral en posicion prona. RELATO DEL CASO: Paciente del sexo masculino, 58 anos, indice de masa corporal de 37,6, con operacion propuesta de descompresion medular asociada a la artrodesis de columna lumbar. Historial de tabaquismo e hipertension arterial sin tratamiento. Examenes fisicos, de laboratorio y cardiologicos normales. La tecnica anestesica utilizada fue la asociacion de anestesia general con cateter peridural. No hubo ninguna complicacion en el intraoperatorio. Al dia siguiente, presento proptosis ocular, edema conjuntival y perdida visual en el ojo izquierdo. CONCLUSIONES: El caso evidencia la posibilidad de la perdida visual despues de la intervencion quirurgica de columna con el paciente en posicion prona. La neuropatia optica isquemica es el resultado del desequilibrio entre la oferta y la demanda de oxigeno en el nervio optico a causa del aumento de la presion intra ocular (PIO) con relacion a la presion arterial sistemica, determinando la mala perfusion del tejido nervioso. Aunque todavia no este clara la causa de esa complicacion, pueden tenerse en cuenta como factores de riesgo, la avanzada edad, arteriosclerosis, diabetes melito, hipertension arterial, tabaquismo, alteraciones en el suministro vascular y la duracion del procedimiento.BACKGROUND AND OBJECTIVES Visual loss is an uncommon complication in the postoperative period of non-ocular procedures and its incidence may be confirmed by the increasing number of studies in the international literature. This report aimed at describing a case of anopsia after prone spinal procedure. CASE REPORT Male patient, 58 years old, body mass index of 37.6 scheduled for spinal cord decompression associated to lumbar spine arthrodesis. Clinical history of smoking and untreated hypertension. Normal physical, lab and cardiologic exams. Patient was anesthetized with general anesthesia associated to epidural catheter. There were no intraoperative complications. The day after, patient presented with ocular proptosis, conjunctival edema and left visual loss. CONCLUSIONS This case evidences the possibility of visual loss after prone spine surgery. Ischemic optic neuropathy results from the unbalance between optic nerve oxygen supply and demand as a consequence of increased intraocular pressure (IOP) as compared to systemic blood pressure, determining poor nervous tissue perfusion. Although the cause of this complication is still not explained, risk factors may be advanced age, atherosclerosis, diabetes mellitus, hypertension, smoking, changes in vascular supply and procedure duration.