Observed medical and surgical complications of prolonged barbiturate coma for refractory status epilepticus

Status Epilepticus: An Update on Pharmacological Management

Status epilepticus (SE) is a neurological emergency that requires timely pharmacological therapy to cease seizure activity. The treatment approach varies based on the time and the treatment stage of SE. Benzodiazepines are considered the first-line therapy during the emergent treatment phase of SE. Antiseizure medicines such as phenytoin, valproic acid, and levetiracetam are recommended during the urgent treatment phase. These drugs appear to have a similar safety and efficacy profile, and individualized therapy should be chosen based on patient characteristics. Midazolam, propofol, pentobarbital, and ketamine are continuous intravenous infusions of anesthetic medications utilized in the refractory SE (RSE) period. The most efficacious pharmacotherapeutic treatments for RSE and superrefractory status epilepticus are not clearly defined.

Association Between Dose Escalation of Anesthetics and Outcomes in Patients With Refractory Status Epilepticus

BACKGROUND AND OBJECTIVES

To investigate the association between dose escalation of continuously administered IV anesthetics and its duration with short-term outcomes in adult patients treated for refractory status epilepticus (RSE).

METHODS

Clinical and electroencephalographic data of patients with RSE without hypoxic-ischemic encephalopathy who were treated with anesthetics at a Swiss academic medical center from 2011 to 2019 were assessed. The frequency of anesthetic dose escalation (i.e., dose increase) and its associations with in-hospital death or return to premorbid neurologic function were primary endpoints. Multivariable logistic regression analysis was performed to identify associations with endpoints.

RESULTS

Among 111 patients with RSE, doses of anesthetics were escalated in 57%. Despite patients with dose escalation having a higher morbidity (lower Glasgow Coma Scale [GCS] score at status epilepticus [SE] onset, more presumably fatal etiologies, longer duration of SE and intensive care, more infections, and arterial hypotension) as compared with patients without, the primary endpoints did not differ between these groups in univariable analyses. Multivariable analyses revealed decreased odds for death with dose escalation (odds ratio 0.09, 95% CI 0.01-0.86), independent of initial GCS score, presumably fatal etiology, SE severity score, SE duration, and nonconvulsive SE with coma, with similar functional outcome among survivors compared with patients without dose escalation.

DISCUSSION

Our study reveals that anesthetic dose escalation in adult patients with RSE is associated with decreased odds for death without increasing the proportion of surviving patients with worse neurofunctional state than before RSE.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that anesthetic dose escalation decreases the odds of death in patients with RSE.

Early timing of anesthesia in status epilepticus is associated with complete recovery: A 7-year retrospective two-center study

OBJECTIVE

This study was undertaken to investigate the efficacy, tolerability, and outcome of different timing of anesthesia in adult patients with status epilepticus (SE).

METHODS

Patients with anesthesia for SE from 2015 to 2021 at two Swiss academic medical centers were categorized as anesthetized as recommended third-line treatment, earlier (as first- or second-line treatment), and delayed (later as third-line treatment). Associations between timing of anesthesia and in-hospital outcomes were estimated by logistic regression.

RESULTS

Of 762 patients, 246 received anesthesia; 21% were anesthetized as recommended, 55% earlier, and 24% delayed. Propofol was preferably used for earlier (86% vs. 55.5% for recommended/delayed anesthesia) and midazolam for later anesthesia (17.2% vs. 15.9% for earlier anesthesia). Earlier anesthesia was statistically significantly associated with fewer infections (17% vs. 32.7%), shorter median SE duration (.5 vs. 1.5 days), and more returns to premorbid neurologic function (52.9% vs. 35.5%). Multivariable analyses revealed decreasing odds for return to premorbid function with every additional nonanesthetic antiseizure medication given prior to anesthesia (odds ratio [OR] = .71, 95% confidence interval [CI] = .53-.94) independent of confounders. Subgroup analyses revealed decreased odds for return to premorbid function with increasing delay of anesthesia independent of the Status Epilepticus Severity Score (STESS; STESS = 1-2: OR = .45, 95% CI = .27-.74; STESS > 2: OR = .53, 95% CI = .34-.85), especially in patients without potentially fatal etiology (OR = .5, 95% CI = .35-.73) and in patients experiencing motor symptoms (OR = .67, 95% CI = .48-.93).

SIGNIFICANCE

In this SE cohort, anesthetics were administered as recommended third-line therapy in only every fifth patient and earlier in every second. Increasing delay of anesthesia was associated with decreased odds for return to premorbid function, especially in patients with motor symptoms and no potentially fatal etiology.

Balancing the risks and benefits of anesthetics in status epilepticus

PURPOSE

According to international guidelines, status epilepticus refractory to first- and second-line antiseizure medication should be treated with anesthetics. Therefore, continuously delivered intravenous midazolam, propofol, or barbiturates are recommended as third-line therapy. While electroencephalographically (EEG)-controlled titration of anesthetics to seizure termination or to the emergence of an EEG burst-suppression pattern makes sense, evidence of the efficacy and tolerability of such third-line treatment is limited and concerns regarding the risks of anesthesia remain. The lack of treatment alternatives and persistent international discord reflecting contradictory results from some studies leave clinicians on their own when deciding to escalate treatment. In this conference-accompanying narrative review, we highlight the challenges of EEG-monitored third-line treatment and discuss recent studies that examined earlier administration of anesthetics.

RESULTS

Based on the literature, maintaining continuous burst suppression is difficult despite the constant administration of anesthetics, and the evidence for burst suppression as an adequate surrogate target is limited by methodological shortcomings as acknowledged by international guidelines. In our Swiss cohort including 102 patients with refractory status epilepticus, burst suppression as defined by the American Clinical Neurophysiology Society's Critical Care EEG Terminology 2021 was established in only 21%. Besides case reports suggesting that rapid but short-termed anesthesia can be sufficient to permanently stop seizures, a study including 205 patients revealed that anesthesia as second-line treatment was associated with a shorter median duration of status epilepticus (0.5 versus 12.5 days, p < 0.001), median ICU (2 versus 5.5 days, p < 0.001) and hospital stay (8 versus 17 days, p < 0.001) with equal rates of complications when compared to anesthesia as third-line treatment.

CONCLUSIONS

Recent investigations have led to important findings and new insights regarding the use of anesthetics in refractory status epilepticus. However, numerous methodological limitations and remaining questions need to be considered when it comes to the translation into clinical practice, and, in consequence, call for prospective randomized studies. This paper was presented at the 8th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures held in September 2022.

Therapeutically induced EEG burst-suppression pattern to treat refractory status epilepticus—what is the evidence?

Current guidelines advocate to treat refractory status epilepticus (RSE) with continuously administered anesthetics to induce an artificial coma if first- and second-line antiseizure drugs have failed to stop seizure activity. A common surrogate for monitoring the depth of the artificial coma is the appearance of a burst-suppression pattern (BS) in the EEG. This review summarizes the current knowledge on the origin and neurophysiology of the BS phenomenon as well as the evidence from the literature for the presumed benefit of BS as therapy in adult patients with RSE.

Escalation to Barbiturate-Induced Coma for Refractory Seizures after Liver Transplantation

Seizures after liver transplantation were previously thought to be a reliable harbinger of catastrophe, but more recent studies have found seizure activity to be relatively common, and most cases do not result in a poor outcome. Generalized seizures are the most common, and they typically occur de novo within the first two weeks after transplantation. The underlying cause for seizure activity in these patients may be complex, with potential etiologies including metabolic, infectious, cerebrovascular, and medication-induced causes. Identification of the underlying cause and the use of antiepileptic drugs (AEDs) is crucial for minimizing risk to the patient's neurologic and overall health. In this report, we present the case of a patient with refractory seizures unresponsive to conventional treatment, requiring prolonged barbiturate burst suppression with ventilator support. Seizure activity eventually ceased, and the patient made a full recovery.

Frequency and Types of Complications Encountered in Patients With Nonconvulsive Status Epilepticus in the Neurological ICU: Impact on Outcome

Objectives. The frequency and types of complications in patients with nonconvulsive status epilepticus (NCSE) who are followed up in the intensive care unit (ICU), and the impact of these complications on outcome are not well-known. We investigated the complications and their effects on prognosis in NCSE patients. Methods. After reviewing the video-EEG monitoring (VEEGM) reports of all the consecutive patients who were followed up in our ICU between 2009 and 2019, we identified two groups of patients: 1-patients with NCSE (study group) and 2-patients who underwent VEEGM for possible NCSE but did not have ictal recordings (no-NCSE group). Electronic health records were reviewed to identify demographic and clinical data, duration of ICU care, medical and surgical complications, pharmacologic treatment, and outcome. These parameters were compared statistically between the groups. We also investigated the parameters affecting prognosis at discharge. Results. Thirty-two patients with NCSE comprised the study group. Infection developed in 84%. More than half were intubated, had tracheostomy or percutaneous endoscopic gastrostomy application. Refractory NCSE was associated with significantly more frequent complications and worse outcome. There was a higher tendency of infections in the study group (P = .059). Higher organ failure scores and prolonged stay in ICU predicted worse outcome (P < .05). Conclusion. The frequency of complications in patients with NCSE who are cared for in the ICU is considerable. Most of the complications are similar to the other patients in ICU, except for the higher frequency of infections. Increased physician awareness about modifiable parameters and timely interventions might help improve prognosis.

Perioperative Treatment of Brain Arteriovenous Malformations Between 2006 and 2014: The Helsinki Protocol

Objective

We reviewed retrospectively the perioperative treatment of microsurgically resected brain arteriovenous malformations (bAVMs) at the neurosurgical department of Helsinki University Hospital between the years 2006 and 2014. We examined the performance of the treatment protocol and the incidence of delayed postoperative hemorrhage (DPH).

Methods

The Helsinki protocol for postoperative treatment of bAVMs was used for the whole patient cohort of 121. The patients who had subsequent DPH were reviewed in more detail.

Results

Five out of 121 (4.1%) patients had DPH. These patients had a higher Spetzler–Martin grade (SMG) (p = 0.043) and a more complex venous drainage pattern (p = 0.003) as compared to those who had no postoperative bleed. Patients with DPH had 43% larger intravenous fluid intake in the neurosurgical intensive care unit (p = 0.052); they were all male (p = 0.040) and had longer stay in the intensive care unit (p = 0.022).

Conclusions

The Helsinki protocol for postoperative treatment of bAVMs was found to produce comparable results to a more complex treatment algorithm. DPH was associated with high SMG, complex venous drainage pattern, male gender and high intravenous fluid intake. Our findings support the use of SMG in defining patient’s postoperative treatment as the DPHs in our study occurred in patients with grade 2–5.

Phenobarbital as alternate anticonvulsant for organophosphate-induced benzodiazepine-refractory status epilepticus and neuronal injury

Objective

Organophosphates (OPs) such as diisopropylfluorophosphate (DFP) and soman are lethal chemical agents that can produce seizures, refractory status epilepticus (SE), and brain damage. There are few optimal treatments for late or refractory SE. Phenobarbital is a second‐line drug for SE, usually after lorazepam, diazepam, or midazolam have failed to stop SE. Practically, 40 minutes or less is often necessary for first responders to arrive and assist in a chemical incident. However, it remains unclear whether administration of phenobarbital 40 minutes after OP intoxication is still effective. Here, we investigated the efficacy of phenobarbital treatment at 40 minutes postexposure to OP intoxication.

Methods

Acute refractory SE was induced in rats by DFP injection as per a standard paradigm. After 40 minutes, subjects were given phenobarbital intramuscularly (30‐100 mg/kg) and progression of seizure activity was monitored by video‐EEG recording. The extent of brain damage was assessed 3 days after DFP injections by neuropathology analysis of neurodegeneration and neuronal injury by unbiased stereology.

Results

Phenobarbital produced a dose‐dependent seizure protection. A substantial decrease in SE was evident at 30 and 60 mg/kg, and a complete seizure termination was noted at 100 mg/kg within 40 minutes after treatment. Neuropathology findings showed significant neuroprotection in 100 mg/kg cohorts in brain regions associated with SE. Although higher doses resulted in greater protection against refractory SE and neuronal damage, they did not positively correlate with improved survival rate. Moreover, phenobarbital caused serious adverse effects including anesthetic or comatose state and even death.

Significance

Phenobarbital appears as an alternate anticonvulsant for OP‐induced refractive SE in hospital settings. A careful risk‐benefit analysis is required because of negative outcomes on survival and cardio‐respiratory function. However, the need for sophisticated support and critical monitoring in hospital may preclude its use as medical countermeasure in mass casualty situations.

Sedatives in neurocritical care: an update on pharmacological agents and modes of sedation

PURPOSE OF REVIEW

In this article, the specific and general indications for sedatives in the neurocritical care unit are discussed, together with an overview on current insights in sedative protocols for these patients. In addition, physiological effects of sedative agents on the central nervous system are reviewed.

RECENT FINDINGS

In the general ICU population, a large body of evidence supports light protocolized sedation over indiscriminate deep sedation. Unfortunately, in patients with severe acute brain injury, the evidence from randomized controlled trials is scarce to nonexistent, and practice is supported by expert opinion, physiological studies and observational or small interventional trials. The different sedatives each have different beneficial effects and side-effects.

SUMMARY

Extrapolating the findings from studies in the general ICU population suggests to reserve deep continuous sedation in the neuro-ICU for specific indications. Although an improved understanding of cerebral physiological changes in patients with brain injury may be helpful to guide individualized sedation, we still lack the evidence base to make broad recommendations for specific patient groups.

Super-Refractory Status Epilepticus Treated with High Dose Perampanel: Case Series and Review of the Literature

Introduction

Acute symptomatic seizures are frequent in the critically ill patient and can be difficult to treat. The novel anticonvulsant perampanel may be effective in the treatment of status epilepticus considering its mechanism of action of being an AMPA antagonist. We present four cases of super refractory status epilepticus treated with high dose perampanel.

Method

Case report.

Cases

Four patients were treated with perampanel for their refractory status epilepticus. One patient had new onset refractory status epilepticus of unknown etiology. Three other patients had status epilepticus as a result of their cardiac arrest. Two of the cardiac arrest patients had myoclonus. In all patients, the additional of perampanel resulted in a reduction of seizure burden without affecting hemodynamics or hepatic or renal function.

Conclusion

Perampanel may be effective in the treatment of super-refractory status epilepticus of varying etiologies. A larger, prospective study is needed to further assess this therapy.

Weaning from antiseizure drugs after new onset status epilepticus

OBJECTIVE

In patients with status epilepticus (SE) without prior epilepsy, there are limited data on the safety of discontinuing antiseizure drugs (ASDs) after seizure control. We aimed to describe seizure recurrence when weaning from ASDs following new onset SE (NOSE).

METHODS

Retrospective review of adult patients with NOSE admitted to Mayo Clinic, Rochester, Minnesota between January 1, 1990 and December 31, 2015 was performed. Weaning was defined as a discontinuation of ASDs following discharge. Patient demographics, SE characteristics, timing of ASD withdrawal, and seizure recurrence were collected.

RESULTS

One hundred seventy-seven patients with mean age 63 ± 18 years were identified; 96 (54.2%) patients had refractory SE (RSE), and 81 (45.8%) had nonrefractory SE. Mean follow-up was 3.8 ± 3.2 years for those successfully weaned off ASDs. One hundred thirty (73.4%) with outpatient follow-up were included in the analysis; 128 (98.5%) patients were discharged on an ASD; 44 of 128 (34.4%) patients underwent weaning from at least 1 ASD following discharge, including 27 of 128 (21.1%) who were completely weaned off of all ASDs. Younger patients (P = 0.009) and those with RSE (P = 0.048, odds ratio = 2.12, 95% confidence interval = 1.00-4.48) tended to undergo weaning. Six of 44 (13.6%) patients had seizure recurrence when weaned off of any ASD, and two of 27 (7.4%) patients completely weaned off all ASDs had seizure recurrence. Two of seven (28.6%) patients who underwent attempted barbiturate weaning experienced seizure recurrence.

SIGNIFICANCE

We found a rate of 13.6% for late seizure recurrence after weaning from at least one ASD in patients with NOSE; seizure recurrence was more likely in patients with RSE treated with barbiturates. Systematic collection of longitudinal data in patients requiring multiple ASDs for NOSE control will provide more conclusive guidance on weaning from ASDs.

Evolution of Cerebral Atrophy in a Patient with Super Refractory Status Epilepticus Treated with Barbiturate Coma

Introduction. Status epilepticus is associated with neuronal breakdown. Radiological sequelae of status epilepticus include diffusion weighted abnormalities and T2/FLAIR cortical hyperintensities corresponding to the epileptogenic cortex. However, progressive generalized cerebral atrophy from status epilepticus is underrecognized and may be related to neuronal death. We present here a case of diffuse cerebral atrophy that developed during the course of super refractory status epilepticus management despite prolonged barbiturate coma. Methods. Case report and review of the literature. Case. A 19-year-old male with a prior history of epilepsy presented with focal clonic seizures. His seizures were refractory to multiple anticonvulsants and eventually required pentobarbital coma for 62 days and midazolam coma for 33 days. Serial brain magnetic resonance imaging (MRI) showed development of cerebral atrophy at 31 days after admission to our facility and progression of the atrophy at 136 days after admission. Conclusion. This case highlights the development and progression of generalized cerebral atrophy in super refractory status epilepticus. The cerebral atrophy was noticeable at 31 days after admission at our facility which emphasizes the urgency of definitive treatment in patients who present with super refractory status epilepticus. Further research into direct effects of therapeutic coma is warranted.