Ismar Lima Cavalcanti

Effects of magnesium sulphate on the pharmacodynamics of rocuronium in patients aged 60 years and older: A randomised trial.

BACKGROUND There is little information on the interaction between magnesium sulphate (MgSO4) and rocuronium in elderly patients. With a growing number of older patients who need surgical procedures, it is increasingly important to study this age group. OBJECTIVE To evaluate the effects of MgSO4 administration on the pharmacodynamics of rocuronium in patients aged 60 years or older. DESIGN A randomised controlled trial. SETTING A tertiary care hospital. PATIENTS Sixty-four patients, aged 60 years or older, American Society of Anesthesiologists (ASA) physical status classes I to III, scheduled for elective oncological head and neck surgery. Exclusion criteria were severe renal insufficiency (calculated creatinine clearance <30 ml min−1), preoperatorive serum magnesium concentration of more than 1.25 mmol l−1 and patients receiving drugs known to affect neuromuscular function. INTERVENTIONS Patients were randomly allocated to one of two groups: in the magnesium group, patients received MgSO4 30 mg kg−1 intravenously, for 10 min, and then a continuous intravenous infusion at a rate of 1 g h−1. The control group received the same volume of physiological saline. Neuromuscular function was evaluated continuously in both groups. MAIN OUTCOME MEASURES Total recovery time was the primary outcome. Onset time, clinical duration, recovery index and recovery time were considered as secondary endpoints. Values are given as mean [SD]. RESULTS Total recovery time from neuromuscular block (NMB) was 113 [36] min in the magnesium group and 101 [39] min in the control group. Clinical duration was 69 [23] min in the magnesium group and 59 [28] min in the control group. Recovery index was 19 [36] min in the magnesium group and 17 [6] min in the control group. Recovery time was 44 [22] min in the magnesium group and 42 [18] min in the control group. There were no statistically significant differences between the groups in any of the recovery indices. In the magnesium group, the mean onset time was 144 [58] s, significantly shorter than the onset time in the group that received physiological saline, which was 187 [90] s (P = 0.03). Group variances were compared using an F test: onset time varied significantly less in the magnesium group (P = 0.02). CONCLUSION In oncology patients of 60 or more years of age, preadministration of MgSO4, with the doses used in this study, significantly reduced the onset time of NMB induced by rocuronium. TRIAL REGISTRATION Clinicaltrials.gov identifier: NCT01804205.

A Randomized Blinded Study of the Left Ventricular Myocardial Performance Index Comparing Epinephrine to Levosimendan following Cardiopulmonary Bypass.

Background The objective was to evaluate the effect of epinephrine and levosimendan on the left ventricle myocardial performance index in patients undergoing on-pump coronary artery by-pass grafting (CABG). Methods In a double-blind, randomized clinical trial, 81 patients (age: 45–65 years) of both genders were randomly divided to receive either epinephrine at a dosage of 0.06 mcg.kg1.min-1 (epinephrine group, 39 patients) or levosimendan at 0.2 mcg.kg1.min-1 (levosimendan group, 42 patients) during the rewarming of cardiopulmonary by-pass (CPB). Hemodynamic data were collected 30 minutes after tracheal intubation, before chest open (pre-CPB) and 10 minutes after termination of protamine (post-CPB). As the primary outcome, we evaluated the left ventricle myocardial performance index by the Doppler echocardiography. The myocardial performance index is the sum of the isovolumetric contraction time and the isovolumetric relaxation time, divided by the ejection time. Secondary outcomes were systolic and diastolic evaluations of the left ventricle and postoperative troponin I and MB-CK levels. Results Of the 81 patients allocated to the research, we excluded 2 patients in the epinephrine group and 6 patients in the levosimendan group because they didn’t wean from CPB in the first attempt. There was no statistical difference between the groups in terms of patient characteristics, risk factors, or CPB time. The epinephrine group had a lower left ventricle myocardial performance index (p = 0.0013), higher cardiac index (p = 0.03), lower systemic vascular resistance index (p = 0.01), and higher heart rate (p = 0.04) than the levosimendan group at the post-CPB period. There were no differences between the groups in diastolic dysfunction. The epinephrine group showed higher incidence of weaning from CPB in the first attempt (95% vs 85%, p = 0.0001) when compared to the levosimendan group and the norepinephrine requirement was higher in the levosimenandan group than epinephrine group (16% vs. 47%; p = 0.005) in post-CPB period. Twenty-four hours after surgery, the plasma levels of troponin I (epinephrine group: 4.5 ± 5.7 vs. levosimendan group: 2.5 ± 3.2 g/dl; p = 0.09) and MB-CK (epinephrine group: 50.7 ± 31 vs. levosimendan group: 37 ± 17.6 g/dl; p = 0.08) were not significantly different between the two groups. Conclusion When compared to levosimendan, patients treated with epinephrine had a lower left ventricle myocardial performance index in the immediate post-CPB period, encouraging an efficient weaning from CPB in patients undergoing on-pump CABG. Trial Registration ClinicalTrials.gov NCT01616069

Oscillatory blood pressure response to the onset of cycling exercise in men: role of group III/IV muscle afferents

What is the central question of this study? Neural feedback from group III/IV muscle afferents has a key role in regulation of cardiovascular responses to exercise. Blood pressure oscillates in the first seconds of dynamic exercise, but the contribution of muscle afferent feedback to this pattern is unclear. What is the main finding and its importance? We demonstrate that attenuation of group III/IV muscle afferent feedback by spinal fentanyl impairs the pressor response after 10 s of moderate leg cycling exercise, but this afferent feedback does not appear to be necessary for induction of the oscillatory pattern of blood pressure at the onset of exercise.

Impacto do ecocardiograma transesofágico intraoperatório na mortalidade em cirurgia de revascularização do miocárdio com circulação extracorpórea

OBJETIVO: avaliar as taxas de mortalidade e morbidade de doentes submetidos a revascularizacao do miocardio (RVM) com circulacao extracorporea (CEC) que utilizaram rotineiramente o ecocardiograma transesofagico intraoperatorio (ETEio). METODOS: estudo retrospectivo, observacional com avaliacao de prontuarios de 360 doentes no periodo entre abril de 2010 a abril de 2012. Foram analisados: idade, peso, altura sexo, EUROscore, diabete melito, fracao de ejecao e arterias acometidas. Os desfechos foram compilados no intra e no pos-operatorio (infarto do miocardio, acidente vascular cerebral, disfuncao renal, hemodialise, fibrilacao atrial, tempo de internacao no centro de tratamento intensivo). RESULTADOS: foram incluidos 53 doentes, com 27 recebendo a monitoracao. Foram excluidos 307 porque nao foram operados pela mesma equipe cirurgica. Os dois grupos foram homogeneos quanto a idade, peso e sexo, porem, a fracao ejecao foi menor no grupo que recebeu o ecotransesofagico (G ETEio: 56,3%; G Nao ETEio: 65,9% ± 11; p=0,01). Nos doentes em que nao foi utilizado o ETEio, a mortalidade foi maior (G ETEio: 0% e G Nao ETEio: 7,6%; p=0,01). Nao houve diferenca significativa entre os grupos quanto a incidencia de acidente vascular encefalico, infarto agudo do miocardio, fibrilacao atrial aguda e lesao renal. CONCLUSAO: a utilizacao do ecocardiograma transesofagico intraoperatorio em pacientes submetidos a revascularizacao do miocardio, com circulacao extracorporea, diminuiu a mortalidade perioperatoria; orientou quanto a utilizacao dos farmacos inotropicos e vasodilatadores e contribuiu para uma melhor evolucao dos doentes.

A 50-50% mixture of nitrous oxide-oxygen in transrectal ultrasound-guided prostate biopsy: A randomized and prospective clinical trial

Introduction Transrectal ultrasound-guided biopsy (TUSPB) is the standard method of diagnosis for prostate cancer, and although it is well tolerated by some patients, it presents a discomfort rate of 65 to 90%, which may be associated with pain. For convenience, it is agreed that a method of analgesia and sedation is necessary. For this purpose, this study aimed to evaluate the impact of inhalation of a 50–50% N2O-O2 gas mixture on pain intensity in these patients. Material and methods Randomized, double-blinded clinical trial, conducted at Antônio Pedro University Hospital (Hospital Universitário Antônio Pedro), Niterói, RJ, Brazil, containing two groups of 42 patients: a control (C) group, which received 100% oxygen inhalation, and a nitrous oxide (NO) group, which received inhalation of the 50–50% N2O-O2 mixture, self-administered during TUSPB. The pain intensity and degree of satisfaction were evaluated through a visual analogue scale (VAS), as was the frequency of adverse events. Results Eighty-four patients were included in the study, with 42 in each group. The mean pain intensity was lower in the NO group than in the C group [2.52 (0–10) vs 5.95 (0–10), p < 0.001], and the degree of satisfaction was higher in the NO group than in the C group (8.14 vs. 4.69, p < 0.001). The adverse effects were somnolence, dizziness, nausea, vomiting, discomfort and euphoria without differences between the groups. Conclusion The 50–50% N2O-O2 mixture was effective in reducing pain intensity and increasing the degree of satisfaction in TUSPB, with tolerable side effects.

Ischemic Postconditioning and Subanesthetic S(+)-Ketamine Infusion: Effects on Renal Function and Histology in Rats

Background. Ischemic postconditioning (IP) in renal Ischemia reperfusion injury (IRI) models improves renal function after IRI. Ketamine affords significant benefits against IRI-induced acute kidney injury (AKI). The present study investigated the effects of IP and IP associated with subanesthetic S(+)-ketamine in ischemia-reperfusion-induced AKI. Methods. Forty-one Wistar rats were randomized into four groups: CG (10), control; KG (10), S(+)-ketamine infusion; IPG (10), IP; and KIPG (11), S(+)-ketamine infusion + IP. All rats underwent right nephrectomy. IRI and IP were induced only in IPG and KIPG by left kidney arterial occlusion for 30 min followed by reperfusion for 24 h. Complete reperfusion was preceded by three cycles of 2 min of reocclusion followed by 2 min of reperfusion. Renal function was assessed by measuring serum neutrophil gelatinase-associated lipocalin (NGAL), creatinine, and blood urea nitrogen (BUN). Tubular damage was evaluated by renal histology. Results. Creatinine and BUN were significantly increased. Severe tubular injury was only observed in the groups with IRI (IPG and KIPG), whereas no injury was observed in CG or KG. No significant differences were detected between IPG and KIPG. Conclusions. No synergic effect of the use of subanesthetic S(+)-ketamine and IP on AKI was observed in this rat model.

Safety and tolerability of controlled-release oxycodone on postoperative pain in patients submitted to the oncologic head and neck surgery

OBJECTIVE To evaluate the safety and tolerability of controlled-release oxycodone in the treatment of postoperative pain of head and neck oncologic resections. METHODS We conducted a prospective, observational and open study, with 83 patients with moderate to severe pain after head and neck oncological operations. All patients received general anesthesia with propofol, fentanyl and sevoflurane. Postoperatively, should they have moderate or severe pain, we began controlled-release oxycodone 20 mg 12/12 b.i.d on the first day and 10 mg b.i.d. on the second. We assessed the frequency and intensity of adverse effects, the intensity of postoperative pain by a verbal numeric scale and the use of rescue analgesia from 12 hours after administration of the drug and between 7 and 13 days after the last oxycodone dose. RESULTS The most common adverse events were nausea, vomiting, dizziness, pruritus, insomnia, constipation and urinary retention, most mild. No serious adverse events occurred. In less than 12 hours after the use of oxycodone, there was a significant decrease in the intensity of postoperative pain, which remained until the end of the study. The rescue medication was requested at a higher frequency when the opioid dose was reduced, or after its suspension. CONCLUSION Controlled release oxycodone showed to be safe and well tolerated and caused a significant decrease in post-operative pain.

Effects of catecholamines on volemic replacement with saline solution and the impact on heart rate variability in rabbits subjected to hemorrhage. A study by spectral analysis

PURPOSE To verify the effects of different catecholamines on volemic expansion and on the autonomic nervous system in rabbits that were subjected to hemorrhage. METHODS Twenty four rabbits subjected to hemorrhage (with a 25% loss of blood volume) and were randomly divided into four experimental groups: 1) HEMO Group underwent replacement with their own blood in an equal volume; 2) SS Group underwent replacement with saline solution (SS) in a volume that corresponded to three times the removed blood volume; 3) ISP Group underwent replacement with SS and isoprenaline; 4) FNL Group underwent replacement with SS and phenylephrine. Spectral Analysis of the heart rate and heart rate variability were performed from the recorded data. Hematocrit was measured throughout the experiment. RESULTS Replacement with SS and an α- or β-agonist did not produce differences in the intravascular retention compared to replacement with SS alone. An analysis of HRV showed that the FNL group maintained the LF/HF ratio better than ISP and SS. CONCLUSIONS No difference in vascular retention when α- or β- agonists were added to SS during post-hemorrhagic recovery. The animals in the FNL group maintained the integrity of the autonomic response within normal physiological standards during hemorrhagic stress.

Severe Intraoperative Shock Related to Mesenteric Traction Syndrome.

Mesenteric traction syndrome is defined as arterial hypotension, facial flushing, and tachycardia related to mesenteric traction. We describe a case of mesenteric traction syndrome refractory to catecholamine and vasopressin infusions. The patient, who had Crohn disease, developed severe distributive shock after mesenteric traction while undergoing resection of an intestinal inflammatory mass, accompanied by facial flushing and unaltered readings for pulse oximetry, capnography, and bispectral index monitoring. The absence of tachycardia in this case was attributed to long-term use of timolol. Arterial pressure returned to baseline level after approximately 30 minutes, and the postoperative period was uneventful.

Derivados canabinóides e o tratamento farmacológico da dor

JUSTIFICATIVA E OBJETIVOS: As propriedades medicinais da Cannabis sativa tem sido relatadas por muitos seculos para o tratamento de diversos disturbios e, mais recentemente, para o tratamento da dor. O objetivo deste estudo foi revisar os principais avancos na farmacologia do sistema endocanabinoide e no potencial uso terapeutico de alguns compostos canabinoides no tratamento de diversas formas de dor. CONTEUDO: Foi realizada uma busca nos bancos de dados Pubmed, Scielo e Lilacs, identificando-se estudos e revisoes da literatura sobre a farmacologia e o uso terapeutico de substâncias canabinoides em dor. Nessa busca foram utilizadas as seguintes palavras-chaves: Cannabis sativa, tetra-hidrocanabinol, canabidiol, sativex®, cannador®, canabinoides, endocanabinoide, dor e dor neuropatica. Os canabinoides sinteticos e os extratos de Cannabis sativa apresentaram efeito analgesico em diversos ensaios clinicos, sugerindo um potencial papel no tratamento da dor, em particular naquela de origem neuropatica. Os canabinoides sinteticos e os extratos de Cannabis sativatambem apresentaram efeitos ansioliticos quando usados como adjuvantes no tratamento da dor no câncer, na artrite reumatoide e na esclerose multipla. Porem, efeitos adversos significativos, como euforia, depressao e sedacao limitam o uso clinico desses agentes canabinoides. CONCLUSAO: Um melhor conhecimento sobre a farmacologia do sistema endocanabinoide, juntamente com os resultados dos estudos envolvendo o tratamento da dor com substâncias de natureza canabinoide, podem ser de grande valor para o desenvolvimento de farmacos que permitam um avanco significativo na terapeutica de pacientes portadores de sindromes dolorosas, em particular nos casos de dificil controle. Porem, mais estudos sao necessarios para confirmar esses resultados e determinar a seguranca desses compostos.BACKGROUND AND OBJECTIVES: Medical properties of Cannabis sativa have been reported for centuries for the treatment of different disorders and, more recently, to manage pain. This study aimed at reviewing major pharmacological advances of the endocannabinoid system and the potential therapeutic use of some cannabinoid compounds to manage different types of pain. CONTENTS: A search was carried out in Pubmed, Scielo and Lilacs databases to identify studies and literature reviews on the pharmacology and therapeutic use of cannabinoids for pain. The following keywords were used: Cannabis sativa, tetra-hydrocannabinol, cannabidiol, sativex®, cannador®, cannabinoids, endocannabinoid, pain and neuropathic pain. Synthetic cannabinoids and Cannabis sativa extracts have shown analgesic effects in several clinical trials, suggesting their potential role for pain management, especially neuropathic pain. Synthetic cannabinoids and CS extracts have also induced anxiolytic effects when used as adjuvants to treat cancer pain, rheumatoid arthritis and multiple sclerosis. However, significant adverse effects, such as euphoria, depression and sedation limit the clinical use of such cannabinoids. CONCLUSION: Further understanding of endocannabinoid system pharmacology, together with study results involving pain management with cannabinoid substances may be very useful for the development of drugs allowing a significant advance in the treatment of patients with painful syndromes, especially difficult to control. However, further studies are needed to confirm such findings and to determine the safety of such compounds.