Luiz Eduardo Imbelloni

Spinal anesthesia in children with isobaric local anesthetics: report on 307 patients under 13 years of age.

Background:  Spinal anesthesia in expert hands is an excellent method for children for appropriate surgery. The aim of this study was to evaluate the effects of spinal anesthesia with isobaric solutions in 307 consecutive cases from May 2001 to August 2002.

Laparoscopic cholecystectomy under spinal anesthesia: comparative study between conventional-dose and low-dose hyperbaric bupivacaine

Background Laparoscopic cholecystectomy has the advantages of causing less postoperative pain and requiring a short hospital stay, and therefore is the treatment of choice for cholelithiasis. This study was designed to compare spinal anesthesia using hyperbaric bupivacaine given as a conventional dose by lumbar puncture or as a low-dose by thoracic puncture. Methods A total of 140 patients with symptomatic gallstone disease were randomized to undergo laparoscopic cholecystectomy with low-pressure CO2 pneumoperitoneum under spinal anesthesia using either conventional lumbar spinal anesthesia (hyperbaric bupivacaine 15 mg and fentanyl 20 mg) or low-dose thoracic spinal anesthesia (hyperbaric bupivacaine 7.5 mg and fentanyl 20 μg). Intraoperative parameters, postoperative pain, complications, recovery time, and patient satisfaction at follow-up were compared between the two treatment groups. Results All procedures were completed under spinal anesthesia, with no cases needing conversion to general anesthesia. Values for time for block to reach the T3 dermatomal level, duration of motor and sensory block, and hypotensive events were significantly lower with low-dose bupivacaine. Postoperative pain was higher for low-dose hyperbaric bupivacaine at 6 and 12 hours. All patients were discharged after 24 hours. Follow-up 1 week postoperatively showed all patients to be satisfied and to be keen advocates of spinal anesthesia. Conclusion Laparoscopic cholecystectomy can be performed successfully under spinal anesthesia. A small dose of hyperbaric bupivacaine 7.5 mg and 20 μg fentanyl provides adequate spinal anesthesia for laparoscopy and, in comparison with hyperbaric bupivacaine 15% and fentanyl 20 μg, causes markedly less hypotension. The low-dose strategy may have an advantage in ambulatory patients because of the earlier recovery of motor and sensory function and earlier discharge.

The Anatomy of the Thoracic Spinal Canal Investigated with Magnetic Resonance Imaging

BACKGROUND: We investigated, with magnetic resonance imaging, the distance of the dura mater to the spinal cord in patients without spinal or medullar disease at the 2nd, 5th, and 10th thoracic segments. METHODS: Fifty patients in the supine position underwent magnetic resonance imaging. Medial sagittal slices of the 2nd, 5th, and 10th thoracic segments were measured for the relative distances using the 1.5-T superconducting system (Gyroscan Intera, Philips Medical Systems, Best, the Netherlands). In 10 patients, the angles relative to the tangent at the insertion point on the skin were measured. RESULTS: The posterior dural-spinal cord distance is significantly greater at the midthoracic region (5th thoracic = 5.8 ± 0.8 mm) than at the upper (2nd thoracic = 3.9 ± 0.8 mm) and lower thoracic levels (10th thoracic = 4.1 ± 1.0 mm) (P < 0.015). There were no differences between interspaces T2 and T10. There was no correlation between age and the measured distance between the dura mater and the spinal cord. The entry angle of the needle at T2 was 9.0° ± 2.5°; at T5, 45.0° ± 7.4°; and at T10, 9.5° ± 4.2°. CONCLUSIONS: This study demonstrated that there is greater depth of the posterior subarachnoid space at the T2, T5, and T10 levels. The greater distance was found at T5.

Continuous spinal anesthesia versus combined spinal epidural block for major orthopedic surgery: prospective randomized study

CONTEXT AND OBJECTIVES In major orthopedic surgery of the lower limbs, continuous spinal anesthesia (CSA) and combined spinal epidural anesthesia (CSE) are safe and reliable anesthesia methods. In this prospective randomized clinical study, the blockading properties and side effects of CSA were compared with single interspace CSE, among patients scheduled for major hip or knee surgery. DESIGN AND SETTING Prospective clinical study conducted at the Institute for Regional Anesthesia, Hospital de Base, São José do Rio Preto. METHODS 240 patients scheduled for hip arthroplasty, knee arthroplasty or femoral fracture treatment were randomly assigned to receive either CSA or CSE. Blockades were performed in the lateral position at the L3-L4 interspace. Puncture success, technical difficulties, paresthesia, highest level of sensory and motor blockade, need for complementary doses of local anesthetic, degree of technical difficulties, cardiocirculatory changes and postdural puncture headache (PDPH) were recorded. At the end of the surgery, the catheter was removed and cerebrospinal fluid leakage was evaluated. RESULTS Seven patients were excluded (three CSA and four CSE). There was significantly lower incidence of paresthesia in the CSE group. The resultant sensory blockade level was significantly higher with CSE. Complete motor blockade occurred in 110 CSA patients and in 109 CSE patients. Arterial hypotension was observed significantly more often in the CSE group. PDPH was observed in two patients of each group. CONCLUSION Our results suggest that both CSA and CSE provided good surgical conditions with low incidence of complications. The sensory blockade level and hemodynamic changes were lower with CSA.

Analgesia pós-operatória para procedimentos cirúrgicos ortopédicos de quadril e fêmur: comparação entre bloqueio do compartimento do psoas e bloqueio perivascular inguinal

BACKGROUND AND OBJECTIVES This study evaluated the efficacy of a single injection of 0.25% bupivacaine in the psoas compartment or inguinal paravascular for postoperative analgesia in patients undergoing orthopedic surgeries using a peripheral nerve stimulator. METHODS One hundred patients who had a lumbar plexus block through the psoas compartment were compared to 100 patients who had an inguinal paravascular block, using a peripheral nerve stimulator, with 40 mL of 0.25% bupivacaine. The analgesia of the ilioinguinal, genitofemoral, lateral femoral cutaneous, femoral, and obturator nerves was assessed 4, 8, 12, 16, 20, and 24 hours after the end of the surgical procedure. Pain severity was also evaluated in the same period. The amount of opioids administered in the postoperative period was recorded. A radiological study with non-ionic contrast was done in five patients in each group to evaluate the dispersion of the anesthetic. RESULTS The ilioinguinal, genitofemoral, lateral femoral cutaneous, femoral, and obturator nerves were blocked in 92% of the patients with psoas compartment block versus 62% in those with inguinal paravascular block. Lumbar plexus block reduced the need for opioids, and 42% of the patients who underwent psoas compartment block and 36% of the patients who underwent inguinal paravascular block did not need additional analgesics in the postoperative period. Analgesia lasted for approximately 21 hours in the psoas compartment block and 15 hours in the inguinal paravascular block. CONCLUSIONS Psoas compartment block and inguinal paravascular block are excellent techniques for postoperative analgesia in orthopedic surgeries, decreasing the need for opioids. This study showed that the injection in the psoas compartment was easier and more effective in blocking the five nerves of the lumbar plexus.JUSTIFICATIVA E OBJETIVOS: Este estudo avaliou a eficacia da injecao unica de bupivacaina a 0,25% no compartimento do psoas ou perivascular inguinal por meio do estimulador de nervos perifericos para analgesia pos-operatoria em pacientes submetidos a intervencoes cirurgicas ortopedicas. METODO: Cem pacientes receberam bloqueio do plexo lombar atraves do compartimento do psoas e foram comparados com 100 pacientes que receberam bloqueio do plexo lombar via perivascular inguinal, identificados pelo estimulador de nervos perifericos com a injecao de 40 mL bupivacaina a 0,25% sem epinefrina. A analgesia nos nervos ilioinguinal, genitofemoral, cutâneo femoral lateral, femoral e obturatorio foi avaliada 4, 8, 12, 16, 20 e 24 horas apos o final da intervencao cirurgica. A intensidade da dor foi tambem avaliada no mesmo periodo. A quantidade de opioides administrada no pos-operatorio foi anotada. Em cinco pacientes de cada grupo, estudo radiografico com contraste nao-ionico foi realizado para avaliar a dispersao da solucao anestesica. RESULTADOS: Os nervos ilioinguinal, genitofemoral, cutâneo femoral lateral, femoral e obturatorio foram bloqueados em 92% dos pacientes no compartimento do psoas versus 62% no bloqueio perivascular inguinal. O bloqueio do plexo lombar reduziu a necessidade de opioides e 42% dos pacientes submetidos ao bloqueio do compartimento do psoas e 36% dos pacientes no bloqueio inguinal nao necessitaram de analgesico adicional no pos-operatorio. A duracao da analgesia foi em torno de 21 horas com bloqueio do compartimento do psoas e 15 horas com bloqueio perivascular inguinal. CONCLUSOES: O bloqueio do compartimento do psoas e perivascular inguinal e uma excelente tecnica para analgesia pos-operatoria em intervencoes cirurgicas ortopedicas reduzindo a necessidade de opioides. Este estudo mostrou que a injecao no compartimento do psoas foi mais facil e mais efetiva no bloqueio dos cinco nervos do plexo lombar.

Bilateral pudendal nerves block for postoperative analgesia with 0.25% S75:R25 bupivacaine: pilot study on outpatient hemorrhoidectomy

BACKGROUND AND OBJECTIVES Hemorrhoidectomy may be performed under several anesthetic techniques and in outpatient regimen. Postoperative pain is severe and may delay discharge. This study aimed at evaluating bilateral pundendal nerves block for post- hemorrhoidectomy analgesia. METHODS Bilateral pundendal nerves block with 0.25% S75:R25 bupivacaine was performed with nerve stimulator in 35 patients submitted to hemorrhoidectomy under spinal anesthesia. Evaluated parameters were pain severity, duration of analgesia, demand analgesia and possible technique-related complications. Data were evaluated 6, 12, 18, 24 and 30 hours after surgery completion. RESULTS Successful pudendal nerves stimulation was achieved in all patients. There has been no severe pain in all evaluated moments. At 12 hours after blockade, all patients had perineal anesthesia; at 18 hours, 17 patients and at 24 hours, 10 patients still presented perineal anesthesia. Postoperative analgesia was optimal for 18 patients; satisfactory, for 5 patients; and unsatisfactory, for 7 patients. Mean analgesic duration was 23.77 hours. There were no changes in blood pressure, heart rate, no nausea and vomiting were observed. All patients had spontaneous micturition. No local anesthetic-related local or systemic complications were observed. Technique was considered excellent by 27 patients and only 3 male patients considered it satisfactory due to penile anesthesia. CONCLUSIONS Bilateral pudendal nerves block oriented by nerve stimulator provides excellent analgesia with low need for opioids, without local or systemic complications and without urinary retention. Controlled studies might be able to show whether this should be the first analgesic option for hemorrhoidectomies. Perineal anesthesia lasting 20.21 hours shall induce further studies with stimulator-oriented pudendal block.

General anesthesia versus spinal anesthesia for laparoscopic cholecystectomy

BACKGROUND AND OBJECTIVES Laparoscopic cholecystectomy is the treatment of choice for cholelithiasis. The objective of this study was to compare the possibility of performing laparoscopic cholecystectomy under spinal anesthesia versus general anesthesia. METHODS Between July 2007 and September 2008, 68 patients with symptoms of cholelithiasis were included in this study. Patients with physical status ASA I and II were randomly divided to undergo laparoscopic cholecystectomy with low-tension pneumoperitoneum with CO(2) under general anesthesia (n = 33) or spinal anesthesia (n = 35). Propofol, fentanyl, rocuronium, sevoflurane, and tracheal intubation were used for general anesthesia. Hyperbaric bupivacaine 15 mg, and fentanyl 20 microg to achieve a sensorial level of T(3) were used for the spinal anesthesia. Intraoperative parameters, postoperative pain, complications, recovery, patient satisfaction, and cost were compared between both groups. RESULTS All surgical procedures were completed with the chosen method and spinal anesthesia was converted to general anesthesia only in one patient. Pain was significantly lower at 2, 4, and 6 hours after the procedure under spinal anesthesia. The cost of the spinal anesthesia was significantly lower than that of the general anesthesia. All patients were discharged after 24 hours. In the postoperative evaluation, all patients were satisfied with the spinal anesthesia and would recommend this procedure. CONCLUSIONS Laparoscopic cholecystectomy with low-pressure pneumoperitoneum with CO(2) can be safely performed under spinal anesthesia. Spinal anesthesia was associated with an extremely low level of postoperative pain, better recovery, and lower cost than general anesthesia.

Anestesia geral versus raquianestesia para colecistectomia videolaparoscópica

JUSTIFICATIVA E OBJETIVOS: A colecistectomia laparoscopica e o tratamento de escolha para a litiase biliar. Este estudo foi idealizado para comparar a possibilidade de se realizar colecistectomia laparoscopica sob raquianestesia comparando com anestesia geral. METODO: Entre julho 2007 e setembro 2008, 68 pacientes com sintomas de calculo na vesicula foram incluidos no estudo. Pacientes com estado fisico ASA I e II foram aleatoriamente separados para serem operados de colecistectomia laparoscopica com pneumoperitonio com baixa pressao de CO2 sob anestesia geral (n = 33) ou raquianestesia (n = 35). A anestesia geral foi realizada com propofol, fentanil, rocuronio, sevoflurano e intubacao traqueal. A raquianestesia foi realizada com 15 mg de bupivacaina hiperbarica com 20 µg fentanil ate que o nivel sensitivo atingisse T3· Parâmetros intraoperatorios, dor pos-operatoria, complicacoes, recuperacao, satisfacao do paciente e custo foram comparados entre os grupos. RESULTADOS: Todos os procedimentos cirurgicos foram completados com o metodo de escolha e apenas um paciente foi convertido da raquianestesia para a anestesia geral. A dor foi significativamente menor a 2, 4 e 6 horas apos o procedimento sob raquianestesia comparado com o grupo que recebeu anestesia geral. O custo da raquianestesia foi significativamente menor. Todos os pacientes foram liberados apos 24 horas. Na avaliacao no pos-operatorio, todos os pacientes ficaram satisfeitos com a raquianestesia e recomendariam esse procedimento. CONCLUSOES: A colecistectomia laparoscopica com pneumoperitonio com baixa pressao de CO2 pode ser realizada com seguranca sob raquianestesia. A raquianestesia foi associada a minima dor pos-operatoria, melhor recuperacao e menor custo do que anestesia geral.

Assessment of the densities of local anesthetics and their combination with adjuvants: an experimental study

BACKGROUND AND OBJECTIVES The relative density of a local anesthetic in relation to that of the cerebrospinal fluid (CSF) at 37 degrees C is one of the most important physical properties that affect the level of analgesia obtained after the subarachnoid administration of the drug. The objective of this study was to determine the density of local anesthetic solutions, with and without glucose, and the combination of the local anesthetic with adjuvants at 20 degrees C, 25 degrees C, and 37 degrees C. METHODS The density (g.mL(-1)) was determined by using a DMA 450 densimeter with a sensitivity of +/- 0.00001 g.mL(-1). The densities, and variations, according to the temperature were obtained for all local anesthetics and their combination with opioids at 20 degrees C, 25 degrees C, and 37 degrees C. The solution is hyperbaric if its density exceeds 1.00099, hypobaric when its density is lower than 1.00019, and isobaric when its density is greater than 1.00019 and lower than 1.00099. RESULTS The densities of both local anesthetics and adjuvants decrease with the increase in temperature. At 37 degrees C, all glucose-containing solutions are hyperbaric. In the absence of glucose, all solutions are hypobaric. At 37 degrees C, morphine, fentanyl, sufentanil, and clonidine are hypobaric. CONCLUSIONS The densities of local anesthetics and adjuvants decrease with the increase in temperature and increase when glucose is added. The knowledge of the relative density helps select the most adequate local anesthetic to be administered in the subarachnoid space.JUSTIFICATIVA E OBJETIVOS: Uma das mais importantes propriedades fisicas que afetam o nivel da analgesia obtida apos a injecao subaracnoidea de um anestesico local e sua densidade relativa a densidade do liquido cefalorraquidiano (LCR) a 37°C. O objetivo deste trabalho foi determinar a densidade das solucoes de anestesicos locais com e sem glicose e a combinacao de anestesico local com adjuvantes a 20°C, 25°C e 37°C em avaliacao laboratorial. METODO: A densidade (g.mL-1) foi medida como auxilio de um densimetro DMA 450, sensivel a ± 0,00001 g.mL-1. A densidade e suas variacoes com a temperatura foram obtidas de todos os anestesicos locais e suas combinacoes com opioides a 20°C, 25°C e 37°C. A solucao e hiperbarica se sua densidade excede a 1,00099, a solucao e hipobarica quando a densidade esta abaixo de 1,00019 e e isobarica quando a densidade e maior que 1,00019 e menor que 1,00099. RESULTADOS: Ambos, anestesicos locais e adjuvantes, exibem diminuicao da densidade quando se aumenta a temperatura. A 37°C, todas as solucoes que contem glicose sao hiperbaricas. Na ausencia de glicose, todas as solucoes sao hipobaricas. A 37°C, morfina, fentanil, sufentanil e clonidina sao hipobaricas. CONCLUSOES: A densidade dos anestesicos locais e adjuvantes diminui com o aumento da temperatura e aumenta com a adicao de glicose. O conhecimento da baricidade, densidade relativa, ajuda na selecao do anestesico local mais adequado e dos adjuvantes para uso subaracnoideo.

Unilateral spinal anesthesia with hypobaric bupivacaine

BACKGROUND AND OBJECTIVES Restricted sympathetic block during spinal anesthesia may minimize hemodynamic changes. In theory, the use of non-isobaric local anesthetics may induce unilateral anesthesia and limit sympathetic blockade to one side of the body. The local anesthetic dose and the time patients need to remain in the lateral position for achieving unilateral spinal anesthesia are not known. This prospective study investigated the incidence of unilateral spinal anesthesia following injection through a 27G Quincke needle of 0.15% hypobaric bupivacaine, prepared with 1.5 ml standard isobaric bupivacaine plus fentanyl (25 microg), in patients in the lateral position with the limb to be operated upwards. METHODS Spinal anesthesia with 0.15% bupivacaine + fentanyl (25 microg) was induced through a 27G Quincke needle in 22 ASA I and II patients undergoing orthopedic surgery. Dural puncture was performed with the patient in the lateral position with the side to be operated upwards. After removal of 3 to 5 ml of CSF, 5 ml of the hypobaric bupivacaine-fentanyl mixture were injected at a speed of 1 ml.15 s-1. Sensory and motor block (pinprick/scale 0 to 3) were compared between operated and contralateral sides. RESULTS Motor and sensory blocks in operated and contralateral sides were significantly different in all moments for both groups. Unilateral spinal anesthesia was obtained in 71% of the patients. No hemodynamic changes were observed in any patient. No patient developed post-dural puncture headache. CONCLUSIONS Hypobaric 0.15% bupivacaine (7.5 mg) associated to fentanyl provided a predominantly unilateral block after twenty minutes in the lateral position. Major advantages of unilateral spinal anesthesia were hemodynamic stability, patient satisfaction and the absence of post-dural puncture headache.