Mioclonías inducidas por salbutamol / Myoclonus induced by salbutamol: A case report

Resumen El salbutamol es un agonista adrenérgico β2 ampliamente empleado en pacientes con enfermedades pulmonares obstructivas y restrictivas. Sus principales efectos secundarios son la taquicardia y el temblor. Las mioclonías son contracciones musculares involuntarias, irregulares, bruscas, breves y repentinas, y pueden ser generalizadas, focales o multifocales. Se presenta el caso de un paciente de 61 años con mioclonías de difícil manejo que solo presentó mejoría tras la suspensión definitiva del agonista adrenérgico β2. Se describen los hallazgos clínicos, las intervenciones y el resultado en las mioclonías asociadas con el uso de salbutamol y se discuten la posible génesis y la importancia de este efecto adverso. Para documentar el caso, se siguieron las recomendaciones de las guías para el reporte de casos (CAse REport, CARE). Aunque en diversos estudios se han descrito mioclonías secundarias al uso de diferentes fármacos, hasta donde se sabe, este sería el cuarto reporte de un caso asociado específicamente con el uso del salbutamol.

Abstract Salbutamol is a β2 adrenergic agonist widely prescribed in patients with obstructive and restrictive lung diseases. The main side effects associated with its use are tachycardia and tremor. Myoclonus is an involuntary, irregular, abrupt, brief and sudden muscular contraction, which can be generalized, focal or multifocal. We report the case of a 61-year-old patient presenting with myoclonus difficult to treat who showed improvement only after the definitive discontinuation of the β2 adrenergic agonist. We describe the clinical findings, the interventions, and the outcomes related to the onset of myoclonus secondary to the use of salbutamol, as well as the possible genesis and importance of this adverse effect. We used the CARE guidelines to delineate the clinical case. Although myoclonus secondary to the use of different drugs has been described in the literature, as far as we know this is the fourth report of salbutamol-induced myoclonus to date.

Effect of gabapentin pretreatment on myoclonus after etomidate: a randomized, double-blind, placebo-controlled study / Efeito do pré-tratamento com gabapentina sobre a mioclonia após etomidato: um estudo randômico, duplo-cego e controlado por placebo

Abstract Aim: To evaluate the effects of three different doses of gabapentin pretreatment on the incidence and severity of myoclonic movements linked to etomidate injection. Method: One hundered patients, between 18 and 60 years of age and risk category American Society of Anesthesiologists I-II, with planned elective surgery under general anesthetic were included in the study. The patients were randomly divided into four groups and 2 h before the operation were given oral capsules of placebo (Group P, n = 25), 400 mg gabapentin (Group G400, n = 25), 800 mg gabapentin (Group G800, n = 25) or 1200 mg gabapentin (Group G1200, n = 25). Side effects before the operation were recorded. After preoxygenation for anesthesia induction 0.3 mg kg−1 etomidate was administered for 10 s. A single anesthetist with no knowledge of the study medication evaluated sedation and myoclonic movements on a scale between 0 and 3. Two minutes after induction, 2 µg kg−1 fentanyl and 0.8 mg kg−1 rocuronium were administered for tracheal intubation. Results: Demographic data were similar. Incidence and severity of myoclonus in Group G1200 and Group G800 were significantly lower than in Group P; sedation incidence and level were appreciably higher compared to Group P and Group G400. While there was no difference in the incidence of myoclonus between Group P and Group G400, the severity of myoclonus in Group G400 was lower than in the placebo group. In the two-hour period before induction other than sedation none of the side effects related to gabapentin were observed in any patient. Conclusion: Pretreatment with 800 mg and 1200 mg gabapentin 2 h before the operation increased the level of sedation and reduced the incidence and severity of myoclonic movements due to etomidate.

Resumo Objetivo: Avaliar os efeitos de três doses diferentes de gabapentina como pré-tratamento sobre a incidência e a gravidade dos movimentos mioclônicos associados à injeção de etomidato. Método: Cem pacientes, entre 18-60 anos, estado físico ASA I-II, programados para cirurgia eletiva sob anestesia geral, foram incluídos no estudo. Os pacientes foram randomicamente divididos em quatro grupos e duas horas antes da operação receberam cápsulas orais de placebo (Grupo P, n = 25), 400 mg de gabapentina (Grupo G400, n = 25), 800 mg de gabapentina (Grupo G800, n = 25) e 1.200 mg de gabapentina (Grupo G1.200, n = 25). Os efeitos colaterais antes da cirurgia foram registados. Após pré-oxigenação para a indução da anestesia, etomidate (0,3 mg.kg−1) foi administrado por 10 segundos. Um único anestesista, cego para a medicação do estudo, avaliou a sedação e os movimentos mioclônicos com uma escala de 0 a 3. Dois minutos após a indução, fentanil (2 µgr.kg−1) e rocurônio (0,8 mg.kg−1) foram administrados para a intubação traqueal. Resultados: Os dados demográficos foram semelhantes. A incidência e a gravidade da mioclonia nos grupos G1.200 e G800 foram significativamente menores do que no Grupo P; a incidência e o nível de sedação foram consideravelmente maiores comparados com o Grupo P e o Grupo G400. Enquanto não houve diferença na incidência de mioclonia entre os grupos P e G400, a gravidade da mioclonia no Grupo G400 foi menor do que no grupo placebo. No período de duas horas antes da indução, nenhum dos efeitos colaterais relacionados à gabapentina, exceto sedação, foi observado em qualquer paciente. Conclusão: O pré-tratamento com 800 mg e 1.200 mg de gabapentina duas horas antes da operação aumentou o nível de sedação e reduziu a incidência e a gravidade dos movimentos mioclônicos associados ao etomidato.

Prevention of etomidate-induced myoclonus during anesthetic induction by pretreatment with dexmedetomidine

Myoclonus induced by etomidate during induction of general anesthesia is undesirable. This study evaluated the effect of dexmedetomidine (DEX) pretreatment on the incidence and severity of etomidate-induced myoclonus. Ninety patients undergoing elective surgical procedures were randomly allocated to three groups (n=30 each) for intravenous administration of 10 mL isotonic saline (group I), 0.5 µg/kg DEX in 10 mL isotonic saline (group II), or 1.0 µg/kg DEX in 10 mL isotonic saline (group III) over 10 min. All groups subsequently received 0.3 mg/kg etomidate by intravenous push injection. The incidence and severity of myoclonus were recorded for 1 min after etomidate administration and the incidence of cardiovascular adverse events that occurred between the administration of the DEX infusion and 1 min after tracheal intubation was recorded. The incidence of myoclonus was significantly reduced in groups II and III (30.0 and 36.7%), compared with group I (63.3%). The incidence of severe sinus bradycardia was significantly increased in group III compared with group I (P<0.05), but there was no significant difference in heart rate in groups I and II. There were no significant differences in the incidence of low blood pressure among the 3 groups. Pretreatment with 0.5 and 1.0 µg/kg DEX significantly reduced the incidence of etomidate-induced myoclonus during anesthetic induction; however, 0.5 µg/kg DEX is recommended because it had fewer side effects.

clinical comparison of etomidate-lipuro, propofol and admixture at induction

The purpose of this study was to compare etomidate-lipuro and propofol and 50%, [1:1] admixture of these agents at induction with special reference to injection pain, hemodynamic changes, and myoclonus. Ninety patients were assigned at random to three groups in which induction was performed with either etomidate-lipuro, propofol or etomidate-lipuro-propofol admixture. After monitorization with bispectral index [BIS] all agents were given with infusion with a perfuser at a constant rate of 200 ml/min till the BIS values decreased to 40. Blood pressure and heart rate were measured every 30 s at this period. Patients were asked for pain at the injection site and observed visually for myoclonus. The time BIS values decreased to 40 [BIS 40 time] and total amounts of induction doses were measured. BIS 40 time measurements were P > E > PE [199.4 +/- 40.9, 176.9 +/- 31.6, 163.5 +/- 20.6 s]. The hemodynamic [systolic, diastolic and mean blood pressures, heart rate] changes were minimal in group PE than other two groups [P = 0.017]. The intensity of myoclonus was graded as mild in 9, moderate in 12, and severe in 5 patients in the group E [76.3%]. Myoclonus was not observed in group PE and group P. There were no injection pain in group PE as the incidence were [83.8%] in group P and in [63.2%] group E. Incidence of hemodynamic changes, myoclonus, and injection pain is significantly lower in group PE. BIS 40 times is least in group PE. We concluded that 1:1 admixture of etomidate-lipuro and propofol is a valuable agent for induction

Myoclonus, seizure, and ventricular fibrillation after intrathecal injection of tranexamic acid

Tranexamic acid is generally used in the treatment of disorders that predispose one to bleeding. It is a synthetic lysine analog that has strong antifibrinolytic activity. Plasminogen binds to fibrin to form plasmin, which in turn degrades fibrin into fibrin degradation products. Tranexamic acid blocks the lysine binding site on plasminogen and prevents interaction with fibrin. Tranexamic acid reduces blood loss in open heart surgery, hip replacement, and gynecology procedures. In this first case of inadvertent intrathecal injection of Tranexamic acid in a pregnant woman, we found that a massive intrathecal injection of Tranexamic acid triggered refractory ventricular fibrillation and cardiovascular collapse, which did not respond to full resuscitation

Myoclonic movements following induction of anesthesia with propofol: a case report.

OBJECTIVE: To report a case of myoclonic movements during an induction of anesthesia using propofol. Abnormal movements resulting from propofol are uncommon but there have been a number of such cases since propofol was introduced. CLINICAL FEATURES: An 1-year-old boy with a diagnosis of obstructive sleep apnea was scheduled to undergo adenotonsillectomy. He demonstrated myoclonic movements during anesthetic induction using propofol. He was then given isoflurane and his airway was secured with an endotracheal tube after full muscle relaxation by succinylcholine. The anesthetic maintenance was uneventful as was the emergence. The patient recovered smoothly without neurological deficit. CONCLUSION: Propofol, an intravenous anesthetic, with strong evidence of anticonvulsant property, could, in susceptible patients, under certain conditions, act as a proconvulsant, and should, thus, be avoided or cautiously used in some patients.

Síndrome serotoninérgica associada ao uso de paroxetina: relato de caso / Serotonin syndrome associated to the use of paroxetine: case report

Relatamos um caso de síndrome seretoninérgica pelo uso de inibidor da recaptação da serotonina, a paroxetina. Tal síndrome por esta droga, sem combinações, ainda não tinha sido descrita na literatura.

Mioclonus espinal secundario a la administración endovenosa de contraste iodado / Spinal myoclonus secondary to the intravenous administration of iodine contrast media

We describe a patient with a longstanding paraplegia who developed spinal myoclonus on 3 different occasions spanning one year, once after an enhanced CT scan and twice after excretory urographies, one of which was also followed by a generalized tonic-clonic seizure. To our knowledge only one case of spinal myoclonus secondary to the administration of intravenous contrast material in a patient with a spinal arteriovenous malformation has yet been reported. Taken together, the findings in these cases suggest that spinal myoclonus following intravenous iodine administration is indicative of an underlying spinal cord lesion.

A functional interaction between GABA and 5-HT in inhibiting picrotoxin-induced myoclonus in rats.

Pretreatment with 5-hydroxytryptophan (5-HTP), a precursor of 5-HT, antagonised while pretreatment with p-chlorophenylalanine (PCPA), a 5-HT depletor, potentiated the myoclonus induced by picrotoxin, a GABA antagonist. Pretreatment with aminooxyacetic acid (AOAA), a GABA transaminase inhibitor, antagonised picrotoxin-induced myoclonus. The combined effect of the least protective doses of AOAA and 5-HTP was greater than the sum of their individual inhibitory effects on picrotoxin-induced myoclonus. Further, AOAA failed to inhibit picrotoxin-induced myoclonus in PCPA pretreated rats. These findings suggest that the central 5-HT-ergic system exerts a facilitatory influence on the GABA-ergic system and thus it is involved in the antimyoclonic action of GABA.

The synergistic protective effect of propranolol & aminooxyacetic acid against picrotoxin-induced myoclonus in rats.

The effect of propranolol was assessed against myoclonus induced by picrotoxin (a known GABA antagonist) in a dose of 3 mg/kg and allylglycine (the inhibitor of GABA synthesis and release) in a dose of 150 mg/kg. A dose-dependent (0.5-2 mg/kg) protective effect was found against both models. Pretreatment of rats with a GABA-reducing dose (100 mg/kg, nonmyoclonic) of allylglycine produced no change in the effect of propranolol against picrotoxin-induced myoclonus. Propranolol thus inhibited myoclonic responses when both the receptor activity and the functional pool of GABA were impaired, suggesting that it produces as antimyoclonic action without the involvement of GABA. However, the drug seems to show a synergistic action with GABA-ergic agents, as greater protection was observed in rats treated concurrently with propranolol and amino-oxyacetic acid, an inhibitor of GABA degradation.

The antimyoclonic action of clonazepam through a GABA--independent mechanism.

The present study investigates whether clonazepam exerts its antimyoclonic action through a GABA independent mechanism. We have studied the antimyoclonic effect of clonazepam and compared it with that of aminooxyacetic acid (AOAA), a GABA transaminase inhibitor, against myoclonus induced by picrotoxin, a GABA receptor antagonist and allylglycine, a drug which inhibits synthesis and release of GABA. We have also investigated the effect of clonazepam against picrotoxin-induced myoclonus in rats pretreated with either AOAA or submyoclonic dose of allylgylycine. Clonazepam pretreatment inhibited both picrotoxin and allylglycine-induced myoelonus whereas AOAA was effective in inhibiting only picrotoxin-induced myoclonus. The protective effect of clonazepam against picrotoxin-induced myoclonus was potentiated by AOAA pretreatment. Moreover, clonazepam afforded protection against picrotoxin-induced myoclonus in rats pretreated with a submyoclonic GABA reducing dose of allylglycine. These findings indicate that a GABA independent mechanism may also be involved in the antimyoclonic action of clonazepam.

Efecto del fenatanyl y nalbufina sobre las mioclonias inducidas por el etomidato / Effects of Pentanyl and nalbuphine on etomidate inducid myoclonus

Se estudia la acción del fentanyl y nalbufina sobre las mioclonias inducidas por el etomidato con el objeto de poder establecer su mecanismo, para lo cual se estudiaron 30 pacientes adultos sometidos a legrado uterino instrumental; manejados con fentanyl, nalbufina o solución salina IV previa inducción de la anestesia con etomeidato. En cada paciente se valoró la PAM, FC y FR; dolor venoso, mioclonias y náuseas y vómitos postoperatorios. Ambos morfínicos previenen o atenúan significativamente la frecuencia e intensidad de las mioclonias, por lo que apoyamos un efecto más específico probablemente a nivel del sistema nigroestriado

Estudo comparativo entre o fentanil e o diazepam na profilaxia das mioclonias produzidas pelo etomidato / Comparative study between fentanyl and diazepam in the prophylaxis of myoclonias produced by etomidate

Realizou-se um estudo comparativo entre o fentanil e o diazepam para avaliar suas eficácias na profilaxia das mioclonias produzidas pelo etomidato. Foram estudadas 45 pacientes submetidas a curetagem uterina pós-abortamento ou semiótica, cuja faixa etária variou de 17 a 63 anos, o peso de 49-83 kg e divididas ao acaso em três grupos (I, II e III). No grupo I foi empregado o sulfato de atropina (0,5mg) e etomidato (0,2 mg.Kg**-1), venoso. No grupo II e III foram empregadas as mesmas substâncias preceditas de diazepam 10 mg (grupo II) e fentanil 100 microng (Grupo III), 120 antes da induçäo. Foram avaliados os seguintes parâmetros: presença e intensidade das mioclonias e necessidade de doses suplementares de etomidato. Em nosso estudo houve uma diminuiçäo näo estatisticamente significativa, na freqüência e intensidade das mioclonias, quando comparados os Grupos II (diazepam) e grupo III (fentanil profilático), com o grupo I (controle). Näo houve diferenças significativas nos três grupos estudados, no que se refere à necessidade de doses suplementares de etomidato