Rates and Trends of Endotracheal Intubation in Patients With Status Epilepticus

Ketamine to Prevent Endotracheal Intubation in Adults with Refractory Non-convulsive Status Epilepticus: A Case Series

BACKGROUND

Non-convulsive status epilepticus (NCSE) is defined as status epilepticus (SE) with no obvious motor phenomenon and is diagnosed based on electroencephalogram (EEG). Refractory SE (RSE) is the persistence of seizures despite treatment with an adequately dosed first-line and second-line agents. Although guidelines for convulsive RSE include third-line agents such as intravenous anesthetic drugs (midazolam, propofol, or barbiturates), the therapeutic approach to NCSE is not well outlined. Treatment with traditional anesthetics invariably includes endotracheal intubation, which is associated with significant adverse events. Comparatively, ketamine, a non-competitive N-methyl-D-aspartate receptor antagonist is not associated with significant cardiorespiratory depression and may help in avoiding intubation.

OBJECTIVE

In this case series, we describe our experience with the early use of intravenous ketamine as the first anesthetic agent in patients with refractory NCSE to avoid endotracheal intubation.

METHODS

We present a case series of nine patients managed in the Neurointensive Care Unit at a university-affiliated tertiary care hospital. The study was approved by the hospital and university institutional review boards and the requirement for informed consent was waived for retrospective analysis of existing data, per institutional policy. All cases of SE were identified from a prospective database, and a subsequent retrospective chart review identified all patients with a diagnosis of refractory NCSE in whom ketamine was used as the first anesthetic agent. The primary endpoint was the avoidance of endotracheal intubation while on ketamine infusion. The secondary endpoint was defined as cessation of both clinical and electrographic seizures recorded on continuous EEG within 24 h of ketamine administration.

RESULTS

A total of nine patients experiencing refractory NCSE were included in this case series, with a median age of 61 (range 26-72) years and seven patients were male. The primary endpoint, avoiding intubation, was achieved in five out of nine (55%) cases. Six patients experienced resolution of refractory NCSE with ketamine administration as the sole anesthetic agent. Four patients required endotracheal intubation and three patients had a failure of seizure cessation with ketamine. Hypersalivation and pneumonia were the most common ketamine associated adverse events. In non-intubated patients, no deaths occurred. One patient was discharged home, four to subacute rehabilitation, one to a long term acute care hospital, and one patient to hospice.

CONCLUSION

The use of ketamine as the primary anesthetic agent may be a reasonable option to avoid endotracheal intubation in a subset of patients with refractory NCSE. This study is limited by its small sample size, retrospective design, and reliance on information obtained from chart review.

Health care disparities in morbidity and mortality in adults with acute and remote status epilepticus: A national study

OBJECTIVE

Although disparities have been described in epilepsy care, their contribution to status epilepticus (SE) and associated outcomes remains understudied.

METHODS

We used the 2010-2019 National Inpatient Sample to identify SE hospitalizations using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM)/ICD-10-CM codes. SE prevalence was stratified by demographics. Logistic regression was used to assess factors associated with electroencephalographic (EEG) monitoring, intubation, tracheostomy, gastrostomy, and mortality.

RESULTS

There were 486 861 SE hospitalizations (2010-2019), primarily at urban teaching hospitals (71.3%). SE prevalence per 10 000 admissions was 27.3 for non-Hispanic (NH)-Blacks, 16.1 for NH-Others, 15.8 for Hispanics, and 13.7 for NH-Whites (p < .01). SE prevalence was higher in the lowest (18.7) compared to highest income quartile (18.7 vs. 14, p < .01). Older age was associated with intubation, tracheostomy, gastrostomy, and in-hospital mortality. Those ≥80 years old had the highest odds of intubation (odds ratio [OR] = 1.5, 95% confidence interval [CI] = 1.43-1.58), tracheostomy (OR = 2, 95% CI = 1.75-2.27), gastrostomy (OR = 3.37, 95% CI = 2.97-3.83), and in-hospital mortality (OR = 6.51, 95% CI = 5.95-7.13). Minority populations (NH-Black, NH-Other, and Hispanic) had higher odds of tracheostomy and gastrostomy compared to NH-White populations. NH-Black people had the highest odds of tracheostomy (OR = 1.7, 95% CI = 1.57-1.86) and gastrostomy (OR = 1.78, 95% CI = 1.65-1.92). The odds of receiving EEG monitoring rose progressively with higher income quartile (OR = 1.47, 95% CI = 1.34-1.62 for the highest income quartile) and was higher for those in urban teaching compared to rural hospitals (OR = 12.72, 95% CI = 8.92-18.14). Odds of mortality were lower (compared to NH-Whites) in NH-Blacks (OR = .71, 95% CI = .67-.75), Hispanics (OR = .82, 95% CI = .76-.89), and those in the highest income quartiles (OR = .9, 95% CI = .84-.97).

SIGNIFICANCE

Disparities exist in SE prevalence, tracheostomy, and gastrostomy utilization across age, race/ethnicity, and income. Older age and lower income are also associated with mortality. Access to EEG monitoring is modulated by income and urban teaching hospital status. Older adults, racial/ethnic minorities, and populations of lower income or rural location may represent vulnerable populations meriting increased attention to improve health outcomes and reduce disparities.

Ketamine Efficacy for Management of Status Epilepticus: Considerations for Prehospital Clinicians

Current first-line therapies for seizure management recommend benzodiazepines, which target gamma-aminobutyric acid type A channels to stop the seizure activity. However, seizures may be refractory to traditional first-line therapies, transitioning into status epilepticus and becoming resistant to gamma-aminobutyric acid type A augmenting drugs. Although there are other antiseizure medications available for clinicians to use in the intensive care unit, these options can be less readily available outside of the intensive care unit and entirely absent in the prehospital setting. Instead, patients frequently receive multiple doses of first-line agents with increased risk of hemodynamic or airway collapse. Ketamine is readily available in the prehospital setting and emergency department, has well-established antiseizure effects with a favorable safety profile, and is a drug often used for several other indications. This article aimed to explore the utilization of ketamine for seizure management in the prehospital setting, reviewing seizure pathophysiology, established treatment mechanisms of action and pharmacokinetics, and potential benefits of early ketamine use in status epilepticus.

Comparison of induction agents for rapid sequence intubation in refractory status epilepticus: A single-center retrospective analysis

Endotracheal intubation, frequently required during management of refractory status epilepticus (RSE), can be facilitated by anesthetic medications; however, their effectiveness for RSE control is unknown. We performed a single-center retrospective review of patients admitted to a neurocritical care unit (NCCU) who underwent in-hospital intubation during RSE management. Patients intubated with propofol, ketamine, or benzodiazepines, termed anti-seizure induction (ASI), were compared to patients who received etomidate induction (EI). The primary endpoint was clinical or electrographic seizures within 12 h post-intubation. We estimated the association of ASI on post-intubation seizure using logistic regression. A sub-group of patients undergoing electroencephalography during intubation was identified to evaluate the immediate effect of ASI on RSE. We screened 697 patients admitted to the NCCU for RSE and identified 148 intubated in-hospital (n = 90 ASI, n = 58 EI). There was no difference in post-intubation seizure (26 % (n = 23) ASI, 29 % (n = 17) EI) in the cohort, however, there was increased RSE resolution with ASI in 24 patients with electrographic RSE during intubation (ASI: 61 % (n = 11/18) vs EI: 0 % (n = 0/6), p =.016). While anti-seizure induction did not appear to affect post-intubation seizure occurrence overall, a sub-group of patients undergoing electroencephalography during intubation had a higher incidence of seizure cessation, suggesting potential benefit in an enriched population.

Management of status epilepticus: a narrative review

Status epilepticus causes prolonged or repetitive seizures that, if left untreated, can lead to neuronal injury, severe disability, coma and death in paediatric and adult populations. While convulsive status epilepticus can be diagnosed using clinical features alone, non-convulsive status epilepticus requires confirmation by electroencephalogram. Early seizure control remains key in preventing the complications of status epilepticus. This is especially true for convulsive status epilepticus, which has stronger evidence supporting the benefit of treatment on outcomes. When status epilepticus becomes refractory, often due to gamma-aminobutyric acid and N-methyl-D-aspartate receptor modulation, anaesthetic drugs are needed to suppress seizure activity, of which there is limited evidence regarding the selection, dose or duration of their use. Seizure monitoring with electroencephalogram is often needed when patients do not return to baseline or during anaesthetic wean; however, it is resource-intensive, costly, only available in highly specialised centres and has not been shown to improve functional outcomes. Thus, the treatment goals and aggressiveness of therapy remain under debate, especially for non-convulsive status epilepticus, where prolonged therapeutic coma can lead to severe complications. This review presents an evidence-based, clinically-oriented and comprehensive review of status epilepticus and its definitions, aetiologies, treatments, outcomes and prognosis at different stages of the patient's journey.

Seizures, Status Epilepticus, and Continuous EEG in the Intensive Care Unit

PURPOSE OF REVIEW

This article discusses the evolving definitions of seizures and status epilepticus in the critical care environment and the role of critical care EEG in both diagnosing seizure activity and serving as a predictive biomarker of clinical trajectory.

RECENT FINDINGS

Initial screening EEG has been validated as a tool to predict which patients are at risk of future seizures. However, accepted definitions of seizures and nonconvulsive status epilepticus encourage a treatment trial when the diagnosis on EEG is indeterminate because of periodic or rhythmic patterns or uncertain clinical correlation. Similarly, recent data have demonstrated the diagnostic utility of intracranial EEG in increasing the yield of seizure detection. EEG has additionally been validated as a diagnostic biomarker of covert consciousness, a predictive biomarker of cerebral ischemia and impending neurologic deterioration, and a prognostic biomarker of coma recovery and status epilepticus resolution. A recent randomized trial concluded that patients allocated to continuous EEG had no difference in mortality than those undergoing intermittent EEG but could not demonstrate whether this lack of difference was because of studying heterogeneous conditions, examining a monitoring tool rather than a therapeutic approach, or examining an outcome measure (mortality) perhaps more strongly associated with early withdrawal of life-sustaining therapy than to a sustained response to pharmacotherapy.

SUMMARY

Seizures and status epilepticus are events of synchronous hypermetabolic activity that are either discrete and intermittent or, alternatively, continuous. Seizures and status epilepticus represent the far end of a continuum of ictal-interictal patterns that include lateralized rhythmic delta activity and periodic discharges, which not only predict future seizures but may be further classified as status epilepticus on the basis of intracranial EEG monitoring or a diagnostic trial of antiseizure medication therapy. In particularly challenging cases, neuroimaging or multimodality neuromonitoring may be a useful adjunct documenting metabolic crisis. Specialized uses of EEG as a prognostic biomarker have emerged in traumatic brain injury for predicting language function and covert consciousness, cardiac arrest for predicting coma recovery, and subarachnoid hemorrhage for predicting neurologic deterioration due to delayed cerebral ischemia.

Early Neurologic Recovery, Practice Pattern Variation, and the Risk of Endotracheal Intubation Following Established Status Epilepticus

OBJECTIVE

To quantify the association between early neurologic recovery, practice pattern variation, and endotracheal intubation during established status epilepticus, we performed a secondary analysis within the cohort of patients enrolled in the Established Status Epilepticus Treatment Trial (ESETT).

METHODS

We evaluated factors associated with the endpoint of endotracheal intubation occurring within 120 minutes of ESETT study drug initiation. We defined a blocked, stepwise multivariate regression, examining 4 phases during status epilepticus management: (1) baseline characteristics, (2) acute treatment, (3) 20-minute neurologic recovery, and (4) 60-minute recovery, including seizure cessation and improving responsiveness.

RESULTS

Of 478 patients, 117 (24.5%) were intubated within 120 minutes. Among high-enrolling sites, intubation rates ranged from 4% to 32% at pediatric sites and 19% to 39% at adult sites. Baseline characteristics, including seizure precipitant, benzodiazepine dosing, and admission vital signs, provided limited discrimination for predicting intubation (area under the curve [AUC] 0.63). However, treatment at sites with an intubation rate in the highest (vs lowest) quartile strongly predicted endotracheal intubation independently of other treatment variables (adjusted odds ratio [aOR] 8.12, 95% confidence interval [CI] 3.08-21.4, model AUC 0.70). Site-specific variation was the factor most strongly associated with endotracheal intubation after adjustment for 20-minute (aOR 23.4, 95% CI 6.99-78.3, model AUC 0.88) and 60-minute (aOR 14.7, 95% CI 3.20-67.5, model AUC 0.98) neurologic recovery.

CONCLUSIONS

Endotracheal intubation after established status epilepticus is strongly associated with site-specific practice pattern variation, independently of baseline characteristics, and early neurologic recovery and should not alone serve as a clinical trial endpoint in established status epilepticus.

TRIAL REGISTRATION INFORMATION

ClinicalTrials.gov Identifier: NCT01960075.