A Comparison of Epidural Anesthesia and Lumbar Plexus-Sciatic Nerve Blocks for Knee Surgery

OBJECTIVES: The efficacy of combined lumbar plexus-sciatic nerve blocks was compared to epidural anesthesia in patients undergoing total knee surgery. PATIENTS AND METHODS: The study included 80 American Society of Anesthesiologists (ASA) Physical Status I-III patients (age range 18 to 65) undergoing knee surgery. The patients were randomly divided into one of two groups. Epidural anesthesia was performed in the epidural anesthesia (EA) group (n=40), and the lumbar plexus and sciatic nerves were blockedin the lumbar plexus-sciatic nerve blocks (LPSB) group (n=40). For each patient, onset of sensory and motor block, degree of motor block, sign of sensory block in the contralateral lower limb for the lumbar plexus-sciatic nerve blocks group, success in providing adequate anesthesia, hemodynamic changes, time of first analgesic request, and patient and surgeon satisfaction with the anesthetic technique were recorded. RESULTS: One patient in the epidural anesthesia group and three patients in the lumbar plexus-sciatic nerve blocks group required general anesthesia due to failed block. There were no significant differences between the two groups regarding the success of providing adequate anesthesia. Eight patients in the lumbar plexus-sciatic nerve blocks group developed contralateral spread. The onset of sensory-motor block and the time of the first analgesic request were significantly later in the lumbar plexus-sciatic nerve blocks group than in the epidural anesthesia group. Although there were no significant differences regarding patient satisfaction with the anesthetic technique between the two groups, surgeon satisfaction was significantly higher in the lumbar plexus-sciatic nerve blocks group than in the epidural anesthesia group. CONCLUSION: The lumbar plexus -sciatic nerve blocks provide effective unilateral anesthesia and may offer a beneficial alternative to epidural anesthesia in patients undergoing total knee surgery

The effects of volatile induction and maintenance of anesthesia and selective spinal anesthesia on QT interval, QT dispersion, and arrhythmia incidence

OBJECTIVE: The effects of sevoflurane general anesthesia and bupivacaine selective spinal anesthesia on QT dispersion (QTd) and corrected QT (QTc) interval were investigated. METHODS AND MATERIALS: This prospective, randomized, double-blind study was conducted between July and September 2009 in the Urology and General Surgery operating rooms. Forty ASA I-II patients undergoing noncardiac surgery were randomized into two groups: Group R (n=20) and Group V (n=20). In Group R, 5 mg bupivacaine was administered into the spinal space. Anesthesia induction in Group V was established with sevoflurane + 0.1 mg/kg vecuronium using the maximum vital capacity technique. Anesthesia was maintained with 2-3% sevoflurane + 50% N2O/O2 inhalation. All patients were tested with a 24-hour Holter ECG device. QT, QTc, and QTd intervals were measured using 12-lead ECG records at 1 and 3 minutes during preinduction, postinduction, postincision and postextubation periods. Mean arterial pressure (MAP), heart rate and ECG records were measured simultaneously. RESULTS: None of the patients displayed arrhythmia. There was no significant difference between the groups with regard to QTd values (p>0.05). However, QTc was longer in Group V than in Group R after the induction of anesthesia at 3 minutes, after the intubation at 1 and 3 minutes, and after the incision at 1 and 3 minutes. MAP and heart rate were generally higher in Group V (

Regional intravenous anesthesia in knee arthroscopy

OBJECTIVE: The goal of the study was to investigate the regional intravenous anesthesia procedure in knee arthroscopy and to evaluate the effects of adding ketamine over the anesthesia block charactery and tourniquet pain. MATERIAL/METHOD: Forty American Society of Anesthesiologists (ASA) II patients who received knee arthroscopy were enrolled. After monitoring, a peripheral IV line was inserted.The venous blood in the lower extremity was evacuated with a bandage, and the proximal cuff of the double-cuff tourniquet was inflated. The patients were randomly split into two groups. While Group P received 80 ml 0.5% prilocaine, Group PK received 0.15 mg/kg ketamine (80 ml in total) via the dorsum of the foot. We recorded onset time of the sensory block, end time of the sensory block, presence of the motor block, the time when the patient verbally reported tourniquet pain and surgical pain, duration of tourniquet tolerance, fentanyl consumption during the operation, time to first analgesic requirement, methemoglobin values at 60 minutes, operative conditions, 24-hour analgesic consumption, discharge time, and hemodynamic parameters. RESULTS: The body mass index (BMI) of the patients who required general anesthesia was significantly higher than the BMI of other patients. The onset time of the sensory block was shorter for those in Group PK, but the time to first analgesic requirement was longer. CONCLUSION: Regional intravenous anesthesia using the doses and volumes commonly used in knee arthroscopy may be an inadequate block among patients with high BMI values. Moreover, the addition of ketamine to the local anesthetic solution may produce a partial solution by shortening the onset of sensory block and prolonging the time until the first analgesic is required

Ropivacaine for Unilateral Spinal Anesthesia; Hyperbaric or Hypobaric?

SummaryBackground and objectivesThe aim of this study was to compare the unilaterality of subarachnoid block achieved with hyperbaric and hypobaric ropivacaine.MethodsThe prospective, randomized trial was conducted in an orthopedics surgical suite. In all, 60 ASA I–III patients scheduled for elective total knee arthroplasty were included in the study. Group Hypo (n=30) received 11.25mg of ropivacaine (7.5mg.mL−1) + 2mL of distilled water (density at room temperature was 0.997) and group Hyper (n=30) received 11.25mg of ropivacaine (7.5mg.mL−1) + 2mL (5mg.mL−1) of dextrose (density at room temperature was 1,015). Patients in the hyperbaric group were positioned with the operated side down and in the 15° Fowler position, versus those in the hypobaric group with the operated side facing up and in the 15° Trendelenburg position. Combined spinal epidural anesthesia was performed midline at the L3–4 lumbar interspace. Hemodynamic and spinal block parameters, regression time, success of unilateral spinal anesthesia, patient comfort, surgical comfort, surgeon comfort, first analgesic requirement time, and adverse effects were assessed.ResultsTime to reach the T10 dermatome level on the operated side was shorter in group Hyper (612.00±163.29s) than in group Hypo (763.63±208.35s) (p<0.05). Time to 2-segment regression of the sensory block level on both the operated and non-operated sides was shorter in group Hypo than in group Hyper.ConclusionBoth hyperbaric and hypobaric ropivacaine (11.25mg) provided adequate and dependable anesthesia for total knee replacement surgery, with a high level of patient and surgeon comfort. Hypobaric local anesthetic solutions provide a high level of unilateral anesthesia, with rapid recovery of both sensory and motor block, and therefore may be preferable in outpatient settings

Regional intravenous anesthesia in knee arthroscopy

OBJECTIVE: The goal of the study was to investigate the regional intravenous anesthesia procedure in knee arthroscopy and to evaluate the effects of adding ketamine over the anesthesia block charactery and tourniquet pain. MATERIAL/METHOD: Forty American Society of Anesthesiologists (ASA) II patients who received knee arthroscopy were enrolled. After monitoring, a peripheral IV line was inserted.The venous blood in the lower extremity was evacuated with a bandage, and the proximal cuff of the double-cuff tourniquet was inflated. The patients were randomly split into two groups. While Group P received 80 ml 0.5% prilocaine, Group PK received 0.15 mg/kg ketamine (80 ml in total) via the dorsum of the foot. We recorded onset time of the sensory block, end time of the sensory block, presence of the motor block, the time when the patient verbally reported tourniquet pain and surgical pain, duration of tourniquet tolerance, fentanyl consumption during the operation, time to first analgesic requirement, methemoglobin values at 60 minutes, operative conditions, 24-hour analgesic consumption, discharge time, and hemodynamic parameters. RESULTS: The body mass index (BMI) of the patients who required general anesthesia was significantly higher than the BMI of other patients. The onset time of the sensory block was shorter for those in Group PK, but the time to first analgesic requirement was longer. CONCLUSION: Regional intravenous anesthesia using the doses and volumes commonly used in knee arthroscopy may be an inadequate block among patients with high BMI values. Moreover, the addition of ketamine to the local anesthetic solution may produce a partial solution by shortening the onset of sensory block and prolonging the time until the first analgesic is required

Patient-Controlled Sedation in Orthopedic Surgery Under Regional Anesthesia: A New Approach in Procedural Sedation

Background and objectives: : Regional anesthesia is a commonly used technique in orthopedic procedures. Sedation should reduce the patient's anxiety and fear while increasing regional anesthesia quality. This study evaluated the hemodynamic changes, level of sedation, both patients’ and surgeons’ levels of satisfaction and potential side effects in patient-controlled sedation using propofol. Methods: This randomized clinical trial studied sixty ASA physical class I-III patients scheduled for total knee replacement surgery under combined spinal-epidural anesthesia. Patients in Group P (n = 30) received propofol via a patient-controlled analgesia device with the following settings: intravenous propofol bolus dose 400 μg.kg_1, 5-minute lockout interval and no basal infusion. In Group S, we infused saline 150 using the same settings. To determine the level of sedation, we used BIS and Observer's Assessment of Alertness/Sedation Scale. For all patients, we recorded the number of requests. As the final evaluation, we scored surgeons’ and patients’ satisfaction on 4-point scales. Results: Both BIS values and OAA/S scores were lower in Group P than in Group S. Patients’ satisfaction was higher in Group P, although there was no significant difference with respect to surgeons’ satisfaction between the groups. The number of requests for sedation was significantly higher in Group S. However, most requests were considered unsuccessful. Conclusion: This study suggests that patient-controlled sedation with propofol can be used efficiently in orthopedic procedures. Keywords: Analgesia, Patient- Controlled, Anesthesia, Epidural, Anesthesia, Spinal, Conscious Sedation, Infusion Pump, Propofo

Tabagismo e efeito de dexmedetomidina e fentanil na intubação traqueal

JUSTIFICATIVA E OBJETIVOS: Comparar os efeitos de dexmedetomidina e fentanil sobre as alterações hemodinâmicas em fumantes crônicos do sexo masculino. MÉTODOS: Este é um estudo prospectivo, randômico e cego. Sessenta pacientes do sexo masculino, tabagistas crônicos, com idades entre 16 e 60 anos foram selecionados. Os pacientes foram alocados aleatoriamente em dois grupos: Grupo D (n = 30) recebeu 1 µg.kg-1 de dexmedetomidina e Grupo F (n = 30) recebeu 3 µg.kg-1 de fentanil em 150 mL de solução salina normal, com início 10 minutos antes da indução da anestesia. Antes da intubação, a frequência cardíaca e a pressão arterial dos pacientes foram medidas. Após a indução da anestesia para intubação endotraqueal, a frequência cardíaca e os valores da pressão arterial foram novamente medidos 1, 3 e 5 minutos após a intubação. RESULTADOS: A frequência cardíaca estava baixa no Grupo D antes da indução da anestesia, intubação e no primeiro e terceiro minutos pósintubação. A pressão arterial sistólica estava baixa no Grupo F antes da intubação. Embora a pressão arterial diastólica estivesse menor antes da indução da anestesia e aos 5 minutos após a intubação em ambos os grupos, ela já estava baixa no Grupo F antes mesmo da intubação. Enquanto a pressão arterial média estava baixa no Grupo D antes da indução anestésica, ela estava baixa no Grupo F antes da intubação. Os valores para o duplo produto (frequência cardíaca vezes pressão arterial sistólica) estavam baixos no Grupo D antes da indução e no 1º e 3º minutos após a intubação. CONCLUSÕES: A dexmedetomidina, aplicada em fumantes crônicos do sexo masculino via infusão a uma dose de 1 µg.kg-1 10 minutos antes de indução anestésica, controla melhor as elevações da frequência cardíaca e do duplo produto a 1 e 3 minutos após a intubação, comparado ao grupo que recebeu 3 µg.kg-1 de fentanil

Efeitos neurotóxicos de sulfato de magnésio intratecal

JUSTIFICATIVA E OBJETIVOS: Avaliar os potenciais efeitos neurotóxicos em nível ultraestrutural desulfato de magnésio administrado por via intratecal em dose única ou múltipla. MÉTODOS: Estudo realizado com 24 ratos Sprague-Dawley, peso médio entre 250 e 300 g. Apósjejum de 4 horas, os ratos receberam 10 mg.kg-1 de cloreto de xilazina por via intraperitoneale, em seguida, foram divididos aleatoriamente em três grupos. Grupo I (n = 8) recebeu 0,9% desoro fisiológico normal, Grupo II (n = 8) recebeu uma injeção de 0,02 mL de sulfato de magnésioa 15% por via intratecal e Grupo III (n = 8) recebeu 0,02 mL de sulfato de magnésio a 15% umavez por dia durante sete dias. As injeções foram aplicadas dentro de 0,40x50 milímetros daárea lombar. Após sete dias, os animais foram sacrificados sob anestesia com uma injeção deformaldeído a 10% na aorta e os tecidos foram fixados. A medula espinal foi, então, examinadae histopatologicamente avaliada sob microscópio eletrônico. O teste de Kruskal-Wallis foi usadopara avaliação estatística. Um valor de p < 0,05 foi considerado estatisticamente significativo. RESULTADOS: Neurodegeneração significativa foi detectada nos ratos que receberam uma únicainjeção ou injeções repetidas de sulfato de magnésio, em comparação com o grupo controle. O escore na avaliação histopatológica desse grupo também foi alto. CONCLUSÃO: Com base no exame de microscopia eletrônica, descobrimos que a administraçãointratecal de sulfato de magnésio induziu neurodegeneração

Plasma levels of interleukin-10 and nitric oxide in response to two different desflurane anesthesia flow rates

OBJECTIVE: This study investigated interleukin-10 and nitric oxide plasma levels following surgery to determine whether there is a correlation between these two variables and if different desflurane anesthesia flow rates influence nitric oxide and interleukin-10 concentrations in circulation. MATERIALS AND METHODS: Forty patients between 18 and 70 years and ASA I-II physical status who were scheduled to undergo thyroidectomy were enrolled in the study. INTERVENTIONS: Patients were allocated into two groups to receive two different desflurane anesthesia flow rates: high flow (Group HF) and low flow (Group LF). MEASUREMENTS: Blood samples were drawn at the beginning (t 0) and end (t 1) of the operation and after 24 h (t 2). Plasma interleukin-10 and nitric oxide levels were measured using an enzyme-linked-immunosorbent assay and a Griess reagents kit, respectively. Hemodynamic and respiratory parameters were assessed. RESULTS: There was no statistically significant difference between the two groups with regard to interleukin-10 levels at the times of measurement. Interleukin-10 levels were increased equally in both groups at times t 1 and t 2 compared with preoperative concentrations. For both groups, nitric oxide circulating concentrations were significantly reduced at times t 1 and t 2 compared with preoperative concentrations. However, the nitric oxide value was lower for Group HF compared to Group LF at t 2. No correlation was found between the IL-10 and nitric oxide levels. CONCLUSION: Clinical usage of two different flow anesthesia forms with desflurane may increase interleukin-10 levels both in Group HF and Group LF; nitric oxide levels circulating concentrations were significantly reduced at times t 1 and t 2 compared with preoperative concentrations; however, at 24 h postoperatively they were higher in Group LF compared to Group HF. No correlation was detected between interleukin-10 and nitric oxide levels