Complications during the management of pediatric refractory status epilepticus with benzodiazepine and pentobarbital infusions

Evaluation for Blood Concentration and Efficacy/Safety of Continuous Administration of Thiamylal in Children

BACKGROUND

Thiamylal exerts excellent sedative effects. However, it is not routinely used because of its serious adverse effects. This study aimed to clarify the target blood concentration range and infusion rate of thiamylal in children by measuring its blood concentration and evaluating its relationship with efficacy and adverse effects.

METHODS

This study was approved by the Ethics Committee of Japanese Red Cross Kumamoto Hospital. The authors included 10 children aged between 1 and 7 years who had received continuous intravenous (IV) infusion of thiamylal for the management of refractory status epilepticus, excluding those who met the exclusion criteria. After a 2 mg/kg bolus injection of thiamylal, continuous IV infusion was initiated at a rate of 2-3 mg/kg/h. Thiamylal concentration in the blood was measured using high-performance liquid chromatography. The State Behavioral Scale and the frequency of bolus injections were used to evaluate efficacy. Blood pressure and heart rate were measured to evaluate adverse effects. Statistical analyses of the time to awakening and the factors affecting it were also conducted.

RESULTS

The State Behavioral Scale score during thiamylal administration was -2 or lower in all cases, suggesting that the depth of sedation was sufficient. The frequency of bolus injections decreased in a blood concentration-dependent manner, suggesting that the frequency tended to decrease, especially at thiamylal blood concentrations of 20 mcg/mL or higher. An increase of the infusion rate to 3 mg/kg/h was recommended, because the blood concentration may not reach 20 mcg/mL at an infusion rate of 2 mg/kg/h. There was also a case in which a rapid increase in blood concentration accompanied by a decrease in blood pressure and heart rate was observed when the infusion rate was increased to 4 mg/kg/h. Furthermore, the time to awakening after the end of administration correlated with the highest blood concentration during administration; therefore, delayed awakening was noted when using a high dose of thiamylal.

CONCLUSIONS

The target blood concentration of thiamylal in children should be 20-30 mcg/mL, and the infusion rate should be based on 3 mg/kg/h.

Survey of Pediatric Status Epilepticus Treatment Practices and Adherence to Management Guidelines (Pedi-SPECTRUM e-Survey)

Aim

Survey of treatment practices and adherence to pediatric status epilepticus (PSE) management guidelines in India.

Methods

This eSurvey was conducted over 35 days (15th October to 20th November 2023) and included questions related to hospital setting; antiseizure medications (ASMs); ancillary treatment; facilities available; etiology; and adherence to PSE management guidelines.

Results

A total of 170 respondents participated, majority of them were working in tertiary level hospitals (94.1%) as pediatric intensivists (56.5%) and pediatricians (19.4%), and were in clinical practice for 2-10 years (46.5%). Majority use intravenous (IV) midazolam and levetiracetam as first- and second-line ASMs (67.1 and 51.2%, respectively). In cases with refractory status epilepticus (RSE), the most commonly used ASM is midazolam infusion (92.4%). For super-refractory status epilepticus (SRSE), the commonly used third-line ASMs include midazolam infusion (34.1%), thiopentone infusion (26.5%), high dose phenobarbitone (18.2%), and ketamine infusion (15.3%). Overall, in cases with SRSE, 44.7% respondents use ketamine infusion, 42.5% use add-on oral topiramate, and 34.7% use high-dose phenobarbitone (1-3 mg/kg/hour) infusion. Most respondents targeted both clinical and EEG seizure control (48.8%). Ancillary treatment used for SRSE included IV pyridoxine (57.1%), methylprednisolone (45.3%), IVIG (42.4%), ketogenic diet (40.6%), and second-line immunomodulation (33.5%). Most common causes were febrile SE, viral encephalitis, and febrile illness-related epilepsy syndrome (60.6%, 52.4%, and 37.1%, respectively). Facilities available included pediatric intensive care units (PICU) (97.1%), mechanical ventilation (98.2%), pediatric neurologist (68.8%), MRI brain (86.5%), EEG (69.4%), and viral PCR (58.2%). The compliance with guidelines for timing of initiation of ASM ranged from 63.5 to 88.8%.

Conclusion

Intravenous midazolam bolus/es, levetiracetam, and midazolam infusion are commonly used first-, second-, and third-line ASMs, respectively. There were wide variations in use of ASMs for RSE and SRSE, ancillary treatment, and compliance to PSE management guidelines.

How to cite this article

Suthar R, Angurana SK, Nallasamy K, Bansal A, Muralidharan J. Survey of Pediatric Status Epilepticus Treatment Practices and Adherence to Management Guidelines (Pedi-SPECTRUM e-Survey). Indian J Crit Care Med 2024;28(5):504-510.

Thiamylal anaesthetic therapy for febrile refractory status epilepticus in children

PURPOSE

To evaluate barbiturate anaesthetic therapy using thiamylal for febrile refractory status epilepticus (fRSE) in children.

METHODS

This was a review of a prospectively-collected database between April 2012-March 2016 for fRSE cases treated with thiamylal anaesthetic therapy in a single paediatric hospital in Japan. The sample comprised 23 children (median age, 23 months) with fRSE that underwent thiamylal anaesthetic therapy for convulsive seizures lasting longer than 60 min, sustained after intravenous administration of benzodiazepine and non-benzodiazepine anticonvulsants. The intervention comprised protocol-based thiamylal anaesthetic therapy with bolus administration. We measured the dose and time required to achieve the burst suppression pattern (BSP) on electroencephalography, seizure recurrence, death, neurological sequelae, and complications.

RESULTS

All patients except one reached the BSP. The thiamylal median dose until reaching the BSP was 27.5 mg/kg, and the median time from thiamylal administration to reaching the BSP was 109.5 min. There was one case of immediate treatment failure and one of withdrawal seizure, but no breakthrough seizure. No deaths occurred during treatment, and neurological sequelae occurred in four cases (17%). Vasopressors were administered in all cases. Other complications included 11 cases of pneumonia and one of enterocolitis.

CONCLUSION

We revealed the time and dose required to reach the BSP with thiamylal anaesthetic therapy using bolus administration in children. Our results suggested that reaching the BSP with bolus administration requires markedly less time than without bolus administration, rarely causes seizure recurrence in paediatric fRSE, and causes haemodynamic dysfunction and infections as often as observed without bolus administration.

Course and Outcome of Children with Convulsive Status Epilepticus Admitted to a Pediatric Intensive Care Unit

Introduction The objective of this study was to describe the course and the outcomes of children with convulsive status epilepticus and to evaluate the differences between two groups of children with new-onset seizures and known seizure disorders. Methods This is a retrospective, single-center study. Children with convulsive status epilepticus admitted to our tertiary care pediatric intensive care unit were included in the study. Medical records were reviewed to obtain the demographic- and seizure-related variables. Results Among 139 children with status epilepticus, 69.7% (n = 99) had a known seizure disorder. Focal seizures were present in 23.9% of children, and 34.6% required intubation; there was an overall mortality rate of 1.2%. The children with new-onset seizures were younger and received electroencephalography (EEG) and neuroimaging more often compared to children with known seizure disorders (p < 0.05). However, an abnormal EEG was more common among children with known seizure disorders (p < 0.001). Conclusions Sub-therapeutic anti-epileptic drugs levels were common among children with known seizure disorders presenting with status epilepticus. Gender, race, insurance status, type of seizures, intubation requirement, lengths of stay, and mortality were not significantly different between the two groups.

Pediatric refractory and super-refractory status epilepticus

PURPOSE

To summarize the available evidence related to pediatric refractory status epilepticus (RSE) and super-refractory status epilepticus (SRSE), with emphasis on epidemiology, etiologies, therapeutic approaches, and clinical outcomes.

METHODS

Narrative review of the medical literature using MEDLINE database.

RESULTS

RSE is defined as status epilepticus (SE) that fails to respond to adequately used first- and second-line antiepileptic drugs. SRSE occurs when SE persist for 24 h or more after administration of anesthesia, or recurs after its withdrawal. RSE and SRSE represent complex neurological emergencies associated with long-term neurological dysfunction and high mortality. Challenges in management arise as the underlying etiology is not always promptly recognized and therapeutic options become limited with prolonged seizures. Treatment decisions mainly rely on case series or experts' opinions. The comparative effectiveness of different treatment strategies has not been evaluated in large prospective series or randomized clinical trials. Continuous infusion of anesthetic agents is the most common treatment for RSE and SRSE, although many questions on optimal dosing and rate of administration remain unanswered. The use of non-pharmacological therapies is documented in case series or reports with low level of evidence. In addition to neurological complications resulting from prolonged seizures, children with RSE/SRSE often develop systemic complications associated with polypharmacy and prolonged hospital stay.

CONCLUSION

RSE and SRSE are neurological emergencies with limited therapeutic options. Multi-national collaborative efforts are desirable to evaluate the safety and efficacy of current RSE/SRSE therapies, and potentially impact patients' outcomes.

Increasing Ketamine Use for Refractory Status Epilepticus in US Pediatric Hospitals

Ketamine is an emerging therapy for pediatric refractory status epilepticus. The circumstances of its use, however, are understudied. The authors described pediatric refractory status epilepticus treated with ketamine from 2010 to 2014 at 45 centers using the Pediatric Hospital Inpatient System database. For comparison, they described children treated with pentobarbital. The authors estimated that 48 children received ketamine and pentobarbital for refractory status epilepticus, and 630 pentobarbital without ketamine. Those receiving only pentobarbital were median age 3 [interquartile range 0-10], and spent 30 [18-52] days in-hospital, including 17 [9-28] intensive care unit (ICU) days; 17% died. Median cost was $148 000 [81 000-241 000]. The pentobarbital-ketamine group was older (7 [2-11]) with longer hospital stays (51 [30-93]) and more ICU days (29 [20-56]); 29% died. Median cost was $298 000 [176 000-607 000]. For 71%, ketamine was given ≥1 day after pentobarbital. Ketamine cases per half-year increased from 2 to 9 ( P < .05). Ketamine is increasingly used for severe pediatric refractory status epilepticus, typically after pentobarbital. Research on its effectiveness is indicated.

Refractory Status Epilepticus in Children: Intention to Treat With Continuous Infusions of Midazolam and Pentobarbital

OBJECTIVE

To describe pediatric patients with convulsive refractory status epilepticus in whom there is intention to use an IV anesthetic for seizure control.

DESIGN

Two-year prospective observational study evaluating patients (age range, 1 mo to 21 yr) with refractory status epilepticus not responding to two antiepileptic drug classes and treated with continuous infusion of anesthetic agent.

SETTING

Nine pediatric hospitals in the United States.

PATIENTS

In a cohort of 111 patients with refractory status epilepticus (median age, 3.7 yr; 50% male), 54 (49%) underwent continuous infusion of anesthetic treatment.

MAIN RESULTS

The median (interquartile range) ICU length of stay was 10 (3-20) days. Up to four "cycles" of serial anesthetic therapy were used, and seizure termination was achieved in 94% by the second cycle. Seizure duration in controlled patients was 5.9 (1.9-34) hours for the first cycle and longer when a second cycle was required (30 [4-120] hr; p = 0.048). Midazolam was the most frequent first-line anesthetic agent (78%); pentobarbital was the most frequently used second-line agent after midazolam failure (82%). An electroencephalographic endpoint was used in over half of the patients; higher midazolam dosing was used with a burst suppression endpoint. In midazolam nonresponders, transition to a second agent occurred after a median of 1 day. Most patients (94%) experienced seizure termination with these two therapies.

CONCLUSIONS

Midazolam and pentobarbital remain the mainstay of continuous infusion therapy for refractory status epilepticus in the pediatric patient. The majority of patients experience seizure termination within a median of 30 hours. These data have implications for the design and feasibility of future intervention trials. That is, testing a new anesthetic anticonvulsant after failure of both midazolam and pentobarbital is unlikely to be feasible in a pediatric study, whereas a decision to test an alternative to pentobarbital, after midazolam failure, may be possible in a multicenter multinational study.