Flumazenil's Reversal of Myoclonic-like Movements Associated with Midazolam in Term Newborns

Paradoxical Reaction to Midazolam in Preterm Neonates: A Case Series

Midazolam is a drug belonging to the benzodiazepine group and is used commonly for seizure control as well as preoperative and procedure-related sedation in neonates. Many adverse effects of midazolam have been reported in the past. Paradoxical stimulation of the central nervous system such as restlessness, nightmare, and hallucinations as well as hypomanic behavior has been reported in adults and children. Seizure is a rare adverse effect of midazolam. Cases of myoclonic movements associated with midazolam have been published worldwide; however, none so far have been reported from India. We report two newborns in our Neonatal Unit, who developed myoclonic seizure after the administration of midazolam. Both of these neonates were preterm, require multiple invasive and noninvasive investigations also leads to parent and clinician stress.

Treatment of pediatric status epilepticus

OPINION STATEMENT

Status epilepticus is characterized by a prolonged, self-sustaining seizure or repeated seizures without return to baseline. The clinical manifestations of status epilepticus in children and adults range from overt generalized convulsions to more subtle behavioral manifestations, including unresponsiveness in the setting of the intensive care unit. Status epilepticus is the most common neurologic emergency of childhood. A large proportion of these episodes are the result of a prolonged febrile seizure or an acute symptomatic etiology. Fortunately, status epilepticus occurs without consequence for many children, but for others, it is correlated with long-term neurologic dysfunction or death. Treatment of status epilepticus should commence promptly upon its recognition, using predefined treatment protocols. The goal of treatment is the rapid termination of the seizure, to minimize the acute and chronic effects of this emergency and to allow for the prompt assessment and management of the underlying precipitant. Currently, the drug class of first choice in the in-hospital and out-of-hospital treatment of status epilepticus is the benzodiazepines, which may need to be quickly followed by a next-line agent, as the efficacy of the benzodiazepines is negatively correlated with seizure duration. Traditionally, these next-line agents have included phenobarbital and phenytoin, but emerging evidence supports the use of intravenous formulations of other antiepileptic drugs. If the first two agents fail, high-dose intravenous midazolam or anesthetic therapy should be rapidly initiated. This paper reviews the current treatment options and strategies for pediatric patients with status epilepticus.

Acute hypomagnesaemia causing intra-operative lower limb movements in a paraplegic patient, despite full neuromuscular blockade

Alterations in electrolyte homeostasis associated with major surgery, intravenous fluid therapy, malnutrition, and critical illness are common but usually non-specific. This case report describes the sudden onset of forceful rhythmic flexion movements in both lower limbs during scoliosis surgery in a 12-year-old paraplegic boy with spina bifida. These movements arose despite adequate depth of anaesthesia, complete neuromuscular blockade, and treatment of hypocalcaemia. They persisted post-operatively after reversal of neuromuscular blockade and emergence from anaesthesia. Hypomagnesaemia was identified and treated post-operatively which coincided with cessation of the movements. We deduce hypomagnesaemia to be the aetiology of this unusual clinical presentation. This report underscores the interdependency of Ca2+ and Mg2+ homeostasis in excitable tissues and emphasizes that abnormalities observed in each cation should not be considered independently. In the perioperative care of spinal fusion patients, hypocalcaemia is a well-recognised and understood complication.

Myoclonus in childhood

The term "myoclonus" sounds esoteric, yet it is part of our normal physiology, occurring as a muscle jerk on drowsiness or falling asleep, during rapid eye movement (REM) sleep, and as hiccoughs. Myoclonus is also a developmental feature of the human nervous system, comprising some of the earliest fetal movements. In pathologic settings, myoclonus may be the only neurologic abnormality, as in essential myoclonus, but more often it is one symptom of a larger neurologic problem. The vast etiologic spectrum of symptomatic myoclonus can be bewildering, but defining the underlying problem may provide the opportunity to develop specific therapies. Otherwise, treatment is merely symptomatic. The approach to the patient should be to verify the nature of the movement disorder and establish a specific etiologic diagnosis. A battery of neurophysiologic, neuroradiologic, and other laboratory studies is needed to localize the origin of the myoclonus and identify causative lesions. Drug treatment is largely empiric but must be systematic and aimed at restoring activities of everyday living. Unlike in epilepsies, in myoclonus multiple drugs usually must be combined to attain functional improvement.

Adverse effects of sedatives in children

The application of sedation/analgesia in paediatric patients is rapidly expanding as less invasive, non-operative techniques of diagnosis and treatment are applied to the paediatric population. Medical providers who are asked to provide sedation may include radiologists, paediatricians, nurses and emergency physicians, as well as anaesthesiologists and intensive care physicians. At the same time, the range of drugs used in these settings has expanded considerably. As there is no single drug fulfilling the criteria for the ideal sedative (rapid-onset, rapid recovery, no adverse effects, immobility appropriate to procedure being performed), multiple drugs may be used in combination. It is imperative that practitioners using drugs for sedation/analgesia in children be aware of the adverse effect profile(s) of these drugs, both individually and in combination. The purpose of this review is to describe the adverse effects of sedative and reversal agents currently used in paediatric sedation/analgesia.

Safety of benzodiazepines in newborns

BACKGROUND

Benzodiazepines are being used in neonatal intensive care units for sedation and control of seizures. However, anecdotal reports suggest that their use in infants may be associated with serious adverse effects (AEs).

OBJECTIVE

To determine the incidence of AEs from benzodiazepine use in preterm and full-term infants.

METHODS

Retrospective chart review of 63 infants who received benzodiazepines as a sedative or anticonvulsant over a 16-month period.

RESULTS

Mean +/- SD gestational age of the infants was 33.1 +/- 6.2 weeks, and birth weight was 2.3 +/- 1.2 kg. Median (range) postnatal age at commencement of drug administration was 19 (5-54) days. Forty-one infants received lorazepam, 8 received midazolam, and 14 received both. Ten (16%) of the infants had 14 documented adverse events: seizures (n = 6), hypotension (n = 5), and respiratory depression (n = 3). Using a validated adverse drug reaction probability scale, a probable association with benzodiazepine use was demonstrated in 12 of the AEs. Due to the retrospective nature of the data, a score for definite association was not attainable. Anticonvulsant administration was required for 4 of 6 infants and, in all cases of respiratory depression, ventilatory support was initiated or increased. Two cases of significant hypotension were treated with inotropes. There was no statistically significant correlation between AEs and benzodiazepine dose or concomitant use of inotropes or analgesics (morphine), although most infants had underlying medical conditions or received multiple drugs that may have predisposed them to experience AEs.

CONCLUSIONS

Administration of benzodiazepines was frequently associated with AEs in full-term and preterm infants. It is possible that underlying illnesses and concomitant drug use predisposed these effects. Until the benefit-to-risk ratio is determined by further studies, judicious use of benzodiazepines is recommended in this vulnerable population.