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Abstract Background and objectives: Arthroscopy for shoulder disorders is associated with severe and difficult to control pain, postoperatively. The addition of clonidine to local anesthetics for peripheral nerve block has become increasingly common, thanks to the potential ability of this drug to reduce the mass of local anesthetic required and to prolonging analgesia postoperatively. The present study aimed to evaluate the success of brachial plexus block for arthroscopic rotator cuff surgery using local anesthetic with or without clonidine. Method: 53 patients of both genders, between 18 and 70 years old, American Society of Anesthesiologists I or II, who were scheduled to undergo arthroscopic shoulder surgery were selected. Patients were then randomized into two groups. The verbal numerical pain scale and the presence of motor block were obtained in the post-anesthetic recovery room and 6, 12, 18 and 24 h postoperatively. Results: The association of clonidine (0.15 mg) to a solution of 0.33% ropivacaine (30 mL) in brachial plexus block for shoulder arthroscopy has not diminished the visual numeric pain scale values, nor the need for opioid rescue postoperatively. There was a lower incidence of nausea/vomiting postoperatively and a significant motor block time prolongation in the group of patients who received clonidine as adjuvant. Conclusions: The use of brachial plexus block with local anesthetic for analgesic postoperative control is well established in the literature. The addition of clonidine in the dose proposed for prolongation of the analgesic effect and reduction of opioid rescue proved unhelpful.

Background and objectives: The intense trauma response triggered by cardiopulmonary bypass can lead to increased morbidity and mortality. The present study evaluated whether clonidine, a drug of the class of α-2 agonists, administered by spinal route, without association with local anesthetics or opioids, reduces this response in cardiac surgery with cardiopulmonary bypass. Method: A total of 27 patients between 18 and 75 years old, divided by non-blinded fashion into a control group (15) and a clonidine group (12), were studied. All patients underwent identical technique of general anesthesia. Then, only the clonidine group received 1 μg kg−1 clonidine by spinal route. Levels of blood glucose, lactate and cortisol were measured at three consecutive times: T1, at the time of installation of invasive arterial pressure; T2, 10 min after the first dose for cardioplegia; and T3, at the time of skin suture; and troponin I values at T1 and T3. The variation of results between T2-T1, T3-T2, and T3-T1 was also evaluated. Results: There was a statistically significant difference only with respect to the variation in blood glucose in the clonidine group: T3-T2, p = 0.027 and T3-T1, p = 0.047. Conclusions: Spinal clonidine at a dose of 1 μg kg−1 did not decrease blood measurements of troponin, cortisol, or lactate. Blood glucose suffered a more moderate variation during the procedure in the clonidine group. This fact, already reported in the literature, requires further investigation to be clarified.

Objetivo: Avaliar a capacidade da clonidina de reduzir a pressão arterial pulmonar de pacientes com hipertensão pulmonar, submetidos a cirurgia cardíaca, seja pela diminuição dos valores pressóricos a partir da aferição direta da pressão de artéria pulmonar, seja pela redução ouabolição da necessidade de dobutamina e nitroprussiato de sódio no intraoperatório. Método: Trata-se de estudo controlado, comparativo, randomizado e duplamente encoberto feito com 30 pacientes portadores de hipertensão arterial pulmonar tipo 2, submetidos a cirurgia cardíaca. Avaliaram-se a pressão média de artéria pulmonar e a posologia de dobutaminae nitroprussiato de sódio em quatro momentos: (M0) antes da administração de 2 µg/kg declonidina intravenosa ou placebo; (M1) decorridos 30 minutos do tratamento testado e antes da circulação extracorpórea; (M2) imediatamente após a circulação extracorpórea; e (M3)10 minutos após a injeção de protamina. Resultados: Não houve diferenças significativas em relação à pressão média de artéria pulmonarem nenhum dos momentos estudados. Entre os grupos não houve também diferença significativa entre as demais variáveis estudadas, como pressão arterial sistêmica média, frequência cardíaca, dosagem total de dobutamina, dosagem total de nitroprussiato de sódio e necessidade do hipnoanalgésico fentanil. Conclusão: A análise dos dados obtidos dos pacientes incluídos neste estudo permite concluir que a clonidina, na dose de 2 µg/kg administrada via intravenosa, não foi capaz de reduzir a pressão média de artéria pulmonar de pacientes com hipertensão pulmonar do grupo 2 (hipertensão venosa pulmonar), submetidos a cirurgia cardíaca, e nem reduzir ou abolir a necessidade da administração de dobutamina e nitroprussiato de sódio no intraoperatório.

Abstract Introduction Shivering, a common intraoperative problem under spinal anesthesia increases the oxygen consumption considerably and is uncomfortable and distressing to the patient, anesthesiologist as well as surgeon. The present study was designed to explore the effectiveness of tramadol, clonidine and dexmedetomidine in the treatment of post spinal anesthesia shivering and to look for their adverse effects. Methods This prospective, randomized, double blinded control study was done on 90 patients who developed shivering under spinal anesthesia. They were randomly allocated into three groups with Group T receiving tramadol 1 mg.kg-1, Group C getting clonidine 1 mcg.kg-1 and Group D patients receiving dexmedetomidine 0.5 mcg.kg-1. The time taken to control shivering, recurrence rate, hemodynamic variables, sedation score and adverse effects were observed. Results Dexmedetomidine was faster in the control of shivering in 5.7 ± 0.79 minutes (min) whereas tramadol took 6.76 ± 0.93 min and clonidine was slower with 9.43 ± 0.93 min. The recurrence rate was much lower in the dexmedetomidine group with 3.3% than for clonidine (10%) and tramadol (23.3%) group. The sedation achieved with dexmedetomidine was better than clonidine and tramadol. The tramadol group had more cases of vomiting (four) and dexmedetomidine group had six cases of hypotension and two cases of bradycardia. Two of the clonidine patients encountered bradycardia and hypotension. Conclusion Dexmedetomidine is better than tramadol and clonidine in the control of shivering because of its faster onset and less recurrence rate. Though complications are encountered in the dexmedetomidine group, they are treatable.