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 l1 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 30mgkg1 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 timewas 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. © 2013 European Society of Anaesthesiology.

Analysis of rocuronium in human plasma by liquid chromatography-tandem mass spectrometry with application in clinical pharmacokinetics

Rocuronium (ROC) is a neuromuscular blocking agent used in surgical procedures which is eliminated primarily by biliary excretion. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for analysis of ROC in human plasma. Separation of ROC and IS (verapamil) was performed using an endcapped C-18 column and a mixture of water:acetonitrile:trifluoracetic acid (50:50:0.1, v/v) as mobile phase. Aliquots of 100 mu L of human plasma were extracted at pH 3, using dichloromethane. The lower limit of quantification of 5 ng/mL shows the high sensitivity of this method. Intra- and inter-assay precision (as relative standard deviation) was all <= 14.2% and accuracy (as relative standard error) did not exceed 10.1%. The validated method was successfully applied to quantify ROC concentrations in patients under surgical procedures up to 6 h after the administration of the 0.4-0.9 mg/kg ROC. The pharmacokinetic parameter estimations of ROC showed AUC/dose of 563 mu g min/mL, total clearance of 2.5 mL/min/kg, volume of distribution at steady state of 190 mL/kg and mean residence time of 83 min. (C) 2013 Elsevier B.V. All rights reserved.

Diferentes frações inspiradas de oxigênio em coelhos hipovolêmicos anestesiados com propofol e submetidos à ventilação mecânica

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Tempo de latência e duração do efeito do rocurônio, atracúrio e mivacúrio em pacientes pediátricos

JUSTIFICATIVA E OBJETIVOS: Os bloqueadores neuromusculares (BNM) são freqüentemente utilizados em anestesia pediátrica e não existe aquele considerado ideal. O objetivo deste trabalho foi avaliar o rocurônio, o atracúrio e o mivacúrio, em crianças, quanto ao tempo de latência e de recuperação, à interferência sobre as variáveis hemodinâmicas e às condições de intubação traqueal. MÉTODO: Sessenta e sete crianças, estado físico ASA I e II, com idade variando de 2 anos e 6 meses a 12 anos, foram anestesiadas com alfentanil (50 µg.kg-1), propofol (3 mg.kg-1), sevoflurano e N2O/O2 e divididas em três grupos: G1 = rocurônio 0,9 mg.kg-1 (n = 22); G2 = atracúrio 0,5 mg.kg-1 (n = 22) e G3 = mivacúrio 0,15 mg.kg-1 (n = 23). A monitorização do bloqueio neuromuscular foi realizada com o método de aceleromiografia no trajeto do nervo ulnar. Foram estudados: o tempo de latência (TL), a duração clínica (T25), o tempo de relaxamento (T75) e o índice de recuperação (T25-75). A pressão arterial média (PAM) e a freqüência cardíaca (FC) foram registradas em seis momentos, bem como as condições encontradas no momento da intubação traqueal. RESULTADOS: A mediana do TL foi de 0,6 minutos em G1, 1,3 minutos em G2 e 1,9 minutos em G3. A mediana do T25 foi em G1 = 38 minutos, G2 = 41,5 minutos e G3 = 8,8 minutos. A mediana do T75 foi em G1 = 57,7 minutos, G2 = 54,6 minutos e G3 = 13,6 minutos. A mediana do índice de recuperação (T25-75) foi em G1 = 19,7 minutos, G2 = 13,1 minutos e G3 = 4,8 minutos. As condições de intubação traqueal foram consideradas excelentes na maioria dos pacientes de ambos os grupos. Não houve modificações clínicas importantes da PAM e da FC. CONCLUSÕES: O rocurônio, 0,9 mg.kg-1, teve o menor tempo de latência e o mivacúrio, 0,15 mg.kg-1, o menor tempo de recuperação nos pacientes pediátricos anestesiados com sevoflurano. Também, o rocurônio, o mivacúrio e o atracúrio não determinaram alterações hemodinâmicas de importância clínica relevante e proporcionaram excelentes condições de intubação traqueal.

Evaluation of intraocular pressure in association with cardiovascular parameters in normocapnic dogs anesthetized with sevoflurane and desflurane

The objective of this study was to determine intraocular pressure (IOP) and cardiac changes in normocapnic dogs maintained under controlled ventilation and anesthetized using sevoflurane or desflurane. Sixteen healthy adult mixed-breed dogs, seven males and nine females, weighing 10-15 kg were used. The dogs were randomly assigned to one of two groups composed of eight animals anesthetized with sevoflurane (SEVO) or desflurane (DESF). In both groups, anesthesia was induced with propofol (10 mg/kg), and neuromuscular blockade was achieved with rocuronium (0.6 mg/kg/h IV). No premedication was given. Ventilation was adjusted to maintain end-tidal carbon dioxide partial pressure at 35 mmHg. Anesthesia was maintained with 1.5 minimum alveolar concentration (MAC) of sevoflurane or desflurane. In both groups IOP was measured by applanation tonometry (Tono-Pen) before induction of anesthesia. IOP, mean arterial pressure (MAP), heart rate (HR), cardiac index (CI) and central venous pressure (CVP) were also measured 45 min after the beginning of inhalant anesthesia and then every 20 min for 60 min. A one-way repeated measures ANOVA was used to compare data within the same group and Student's t-test was used to assess differences between groups. P < 0.05 was considered statistically significant. Measurements showed normal IOP values in both groups, even though IOP increased significantly from baseline during the use of desflurane. IOP did not differ between groups. CI in the desflurane group was significantly greater than in the sevoflurane group. Sevoflurane and desflurane have no clinically significant effects on IOP, MAP, HR, CI or VCP in the dog.

Tempo de latencia do rocuronio e da succinilcolina e condicoes de intubacao traqueal

Background and Objectives - Pulmonary aspiration of gastric content during induction of anesthesia for emergency surgical procedures is a serious complication; fast endotracheal intubation under these circumstances is of vital importance to secure the airways. Despite its numerous side effects, succinylcholine is used for this purpose. Rocuronium is the most recently introduced aminoesteroid neuromuscular blocking drug with short onset. The objective of this study was to compare the onset time and intubating conditions of rocuronium and succinylcholine. Methods - After informed consent, forty-five patients were randomly allocated into three groups of 15: Group I (GI) = succinylcholine 1 mg.kg-1; Group II (GII) = rocuronium 0.6 mg.kg-1; Group III (GIII) = rocuronium 0.9 mg.kg-1. Every patient was premedicated with midazolam 15 mg per os and induction of anesthesia was made with fentanyl 10 μg.kg-1 and etomidate 0.3 mg.kg-1. The neuromuscular block was monitored with the TOP-Guard neuromuscular transmission monitor. The TOP-Guard neuromuscular monitor uses an accelerometer to measure the response to nerve stimulation. The stimulating electrodes were placed close to the course of the ulnar nerve at the wrist. The onset time was considered as the time between the end of neuromuscular drug injection and the twitch height (T1) decrease to 10%. Heart rate and arterial blood pressure were registered at 6 moments before and after induction of anesthesia. Results - The onset time results were: Group I, 71 s; Group II, 120 s and Group III, 70 s or GI = GIII < GII (F = 8.862; p < 0.01). There were 43 patients exhibiting excellent intubating conditions and 2 with good intubating conditions. Heart rate and arterial blood pressure showed alterations due to induction of anesthesia and intubation. Conclusions - Rocuronium 0.9 mg.kg-1 can be used in rapid sequence induction because it has a short onset time which is similar to that of succnylcholine. It is likely that rocuronium would be a good indication in patients with high intracranial pressure, burns and neuromuscular diseases.

Tempo de latencia e duracao do efeito do brometo de rocuronio no paciente submetido ao transplante renal

Background and Objectives - Successful cadaver kidney transplantation relies on a fast procedure. Patients with chronic renal failure may present with a delayed gastric emptying making it critical a fast tracheal intubation and airway maintenance. Rocuronium a recently introduced nondepolarizing neuromuscular blocker with a fast onset. The aim of this study was to evaluate onset time and duration of rocuronium effects in patients undergoing renal transplantation. Methods - Sixty patients were allocated into two groups of 30: Group R (GR) = patients undergoing renal transplantation and Group N (GN) = patients with normal renal function. All patients were premedicated with oral midazolam (15 mg) and anesthesia was induced with 30 μg.kg-1 alfentanil, 0.3 mg.kg-1 etomidate and 0.6 mg.kg-1 rocuronium injected through a central venous catheter. neuromuscular block was monitored by acceleromyography in the ulnar nerve pathway. The following parameters were evaluated: time between administration of rocuronium and first twitch reduction to 5% after supra-maximal stimulation (T1) (onset time = OT); time for first twitch to return to 25% (clinical duration = R25); time elapsed between 25% and 75% recovery of first twitch (relaxation recovery time = R25-75). Heart rate (HR) and mean blood pressure (MBP) were recorded in 6 moments. Results - Median OT was 31 sec. in GR and 47 sec. in GN. Median R25 was 51.5 min in GR and 33.5 min in GN. Median R25-75 was 28 min in GR and 20 min in GN. MBP and HR were higher in GR. Tracheal intubation conditions were excellent for most patients in both groups. Conclusions - These results open the possibility of 0.6 mg.kg-1 rocuronium being injected through a central venous catheter when a faster onset is needed. Due to wide differences in individual responses, monitoring of neuromuscular block is recommended.

Disfunção temporária do nervo lingual após uso de máscara laríngea. Relato de caso

BACKGROUND AND OBJECTIVES: The laryngeal mask has been frequently used in Anesthesiology. Although the rate of complications with this technique is smaller than that of the endotracheal tube, it is not devoid of risks, especially in cases of difficult airways. The objective of this study was to report a case of unilateral lingual nerve damage after the use of the laryngeal mask airway. CASE REPORT: A female patient underwent a surgical procedure for removal of bilateral breast prosthesis under general, balanced anesthesia, with a size three laryngeal mask. The balloon was inflated with 30 mL of air. After the first postoperative hour, she developed decreased sensation and pain in the oropharynx and posterior two thirds of the tongue, which evolved for loss of taste in the next 24 hours. A tentative diagnosis of lingual nerve neuropraxis secondary to the use of the laryngeal mask was made. After three weeks, her symptoms subsided. CONCLUSION: Although complications after the use of the laryngeal mask airway are rare, they do occur, and neuropraxis of the lingual nerve is one of them. The diagnosis is clinical and it has a good outcome, with resolution of the symptoms within a few weeks or months. © Sociedade Brasileira de Anestesiologia, 2007.

Anestesia para colecistectomía videolaparoscópica en paciente portador de enfermedad de Steinert. Relato de caso y revisiõn de la literatura

BACKGROUND AND OBJECTIVES: Myotonic dystrophies are autosomal dominant neuromuscular diseases. Among them, myotonic dystrophy type 1 (MD1), or Steinert disease, is the most common in adults, and besides muscular involvement it also has important systemic manifestations. Myotonic dystrophy type 1 poses a challenge to the anesthesiologist. Those patients are more sensitive to anesthetics and prone to cardiac and pulmonary complications. Besides, the possibility of developing malignant hyperthermia and myotonic episodes is also present. CASE REPORT: This is a 39-year old patient with DM1 who underwent general anesthesia for videolaparoscopic cholecystectomy. Total intravenous anesthesia with propofol, remifentanil, and rocuronium was the technique chosen. Intercurrences were not observed in the 90-minute surgical procedure, but after extubation, the patient developed respiratory failure and myotonia, which made tracheal intubation impossible. A laryngeal mask was used, allowing adequate oxygenation, and mechanical ventilation was maintained until full recovery of the respiratory function. The patient did not develop further complications. CONCLUSIONS: Myotonic dystrophy type 1 presents several particularities to the anesthesiologist. Detailed knowledge of its systemic involvement along with the differentiated action of anesthetic drugs in those patients will provide safer anesthetic-surgical procedure.

Variação da pressão sistólica como indicadora precoce de hipovolemia e guia de reposição volêmica com solução hiperosmótica e hiperoncótica no cão

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação de diferentes frações inspiradas de oxigênio em cães anestesiados com infusão contínua de propofol e rocurônio, mantidos em ventilação controlada a pressão

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Perfil de citocinas inflamatórias em indivíduos submetidos a procedimentos cirúrgicos utilizando propofol ou isoflurano

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Administração subaracnóide de anestésicos locais em coelhos anestesiados com isofluorano e submetidos ou não à hipovolemia aguda: avaliação da técnica anestésica e eletrofisiologia cardíaca

Pós-graduação em Cirurgia Veterinária - FCAV

Avaliação de diferentes frações inspiradas de oxigênio em coelhos submetidos ao pneumoperitônio e mantidos em cefalodeclive

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)