Advances in the management of seizures and status epilepticus in critically ill patients

Electroencephalogram Monitoring in Critical Care

Seizures are common in critically ill patients. Electroencephalogram (EEG) is a tool that enables clinicians to provide continuous brain monitoring and to guide treatment decisions-brain telemetry. EEG monitoring has particular utility in the intensive care unit as most seizures in this setting are nonconvulsive. Despite the increased use of EEG monitoring in the critical care unit, it remains underutilized. In this review, we summarize the utility of EEG and different EEG modalities to monitor patients in the critical care setting.

Seizures in the critically ill

Critically ill patients with seizures are either admitted to the intensive care unit because of uncontrolled seizures requiring aggressive treatment or are admitted for other reasons and develop seizures secondarily. These patients may have multiorgan failure and severe metabolic and electrolyte disarrangements, and may require complex medication regimens and interventions. Seizures can be seen as a result of an acute systemic illness, a primary neurologic pathology, or a medication side-effect and can present in a wide array of symptoms from convulsive activity, subtle twitching, to lethargy. In this population, untreated isolated seizures can quickly escalate to generalized convulsive status epilepticus or, more frequently, nonconvulsive status epileptics, which is associated with a high morbidity and mortality. Status epilepticus (SE) arises from a failure of inhibitory mechanisms and an enhancement of excitatory pathways causing permanent neuronal injury and other systemic sequelae. Carrying a high 30-day mortality rate, SE can be very difficult to treat in this complex setting, and a portion of these patients will become refractory, requiring narcotics and anesthetic medications. The most significant factor in successfully treating status epilepticus is initiating antiepileptic drugs as soon as possible, thus attentiveness and recognition of this disease are critical.

The safety of lacosamide for treatment of seizures and seizure prophylaxis in adult hospitalized patients

BACKGROUND

Lacosamide (LCM) is a newer antiepileptic drug (AED) with favorable properties for hospitalized patients including intravenous formulation, minimal hepatic metabolism, and no adverse respiratory effects. We sought to determine the safety profile of LCM in hospitalized patients.

METHODS

We performed a retrospective medical record review of patients who received LCM between July 1, 2009, and January 31, 2010, at Mayo Clinic Hospital. Data included demographics, LCM dosing, concomitant AED therapy, documented seizure activity, hemodynamic variables, electrocardiogram (ECG), and laboratory data. Adverse drug reaction and drug-drug interactions were reviewed.

RESULTS

Thirty-two patients were identified. No major hypotension or serious cardiac arrhythmias occurred. Heart rate increased, however, in seizure group compared with the prophylaxis group 2 hours postdrug infusion (median heart rate = 86 vs 164). The ECGs demonstrated a mean PR interval prolongation of about 6 milliseconds (ms) after LCM initiation (mean PR 185.5 ms, compared with baseline ECG mean of 179.3 ms). Laboratory data revealed no clinically significant changes 24 hours after LCM initiation. Three patients developed adverse events (9.4%): One with altered mental state and exceptionally prolonged ECG PR interval (212 vs 178 ms baseline); One with unexplained thrombocytopenia; and a third patient with dizziness, all of which resolved after drug discontinuation.

CONCLUSION

The LCM demonstrated ECG PR prolongation as previously reported without systemic hypotension, with no discernable drug-drug interactions in hospitalized patients. About 9% of patients had transient adverse drug reactions after LCM, namely alteration in mental state, unexplained thrombocytopenia, and dizziness, which stopped after discontinuation of the drug.

Post-hypothermia fever is associated with increased mortality after out-of-hospital cardiac arrest

OBJECTIVE

Post-cardiac arrest fever has been associated with adverse outcome before implementation of therapeutic hypothermia (TH), however the prognostic implications of post-hypothermia fever (PHF) in the era of modern post-resuscitation care including TH has not been thoroughly investigated. The aim of the study was to assess the prognostic implication of PHF in a large consecutive cohort of comatose survivors after out-of-hospital cardiac arrest (OHCA) treated with TH.

METHODS

In the period 2004-2010, a total of 270 patients resuscitated after OHCA and surviving a 24-h protocol of TH with a target temperature of 32-34°C were included. The population was stratified in two groups by median peak temperature (≥38.5°C) within 36h after rewarming: PHF and no-PHF. Primary endpoint was 30-days mortality and secondary endpoint was neurological outcome assessed by Cerebral Performance Category (CPC) at hospital discharge.

RESULTS

PHF (≥38.5°C) was associated with a 36% 30-days mortality rate compared to 22% in patients without PHF, plog-rank=0.02, corresponding to an adjusted hazard rate (HR) of 1.8 (95% CI: 1.1-2.7), p=0.02). The maximum temperature (HR=2.0 per °C above 36.5°C (95% CI: 1.4-3.0), p=0.0005) and the duration of PHF (HR=1.6 per 8h (95% CI: 1.3-2.0), p<0.0001) were also independent predictors of 30-days mortality in multivariable models. Good neurological outcome (CPC1-2) versus unfavourable outcome (CPC3-5) at hospital discharge was found in 61% vs. 39% in the PHF group compared to 75% vs. 25% in the No PHF group, p=0.02.

CONCLUSIONS

Post-hypothermia fever ≥38.5°C is associated with increased 30-days mortality, even after controlling for potential confounding factors. Avoidance of PHF as a therapeutic target should be evaluated in prospective randomized trials.

Body temperature changes are associated with outcomes following in-hospital cardiac arrest and return of spontaneous circulation

INTRODUCTION

Spontaneous changes in body temperature after return of circulation (ROSC) from cardiac arrest are common, but the association of these changes with outcomes in hospitalized patients who survive to 24h post-ROSC is not known. We tested the hypothesis that adults who experience temperature lability in the first 24h have worse outcomes compared with those who maintain normothermia.

MATERIALS AND METHODS

A prospective observational study from a multicenter registry of cardiac arrests (National Registry of Cardiopulmonary Resuscitation) from 355 US and Canadian hospitals. 14,729 adults with return of circulation from a pulseless cardiac arrest. We excluded those who died or were discharged before 24h post-event, those made Do-Not-Resuscitate (DNR) within 24h of event, those that had a preceding trauma, and those with multiple cardiac arrests. Finally, we included only subjects that had both a lowest (T(min)) and highest (T(max)) body temperature value recorded during the first 24-h after ROSC, resulting in a study sample of 3426 patients.

RESULTS

After adjustment for potential covariates, there was a lower odds of survival in those having an episode of hypothermia (adjusted odds ratio [OR], 0.62; 95% confidence interval [CI], 0.48-0.80), those having an episode of hyperthermia (OR, 0.67; 95% CI, 0.48-0.80), and those having an episode of both (OR, 0.59; 95% CI, 0.39-0.91). Among those who survived to discharge, there was also a lower odds of favorable neurologic performance in those who had an episode of hyperthermia (OR, 0.71; 95% CI, 0.51-0.98).

CONCLUSIONS

Episodes of temperature lability following in-hospital resuscitation from cardiac arrest are associated with lower odds of surviving to discharge. Hyperthermia is also associated with fewer patients leaving the hospital with favorable neurologic performance. Further studies should identify whether therapeutic control over changes in body temperature after in-hospital cardiac arrest improves outcomes.

Effect of concomitant administration of meropenem and valproic acid in an elderly Chinese patient

BACKGROUND

Meropenem is a carbapenem with a broad spectrum of activity against beta-lactamase-producing organisms. Valproic acid is widely used in the treatment of generalized tonic-clonic and partial seizures. Concomitant administration of meropenem and valproic acid reportedly leads to a rapid decline in serum concentrations of valproic acid, which is sometimes associated with seizures.

CASE SUMMARY

This report describes an 85-year-old Chinese male inpatient who twice received concomitant administration of meropenem and valproic acid for the treatment of pneumonia and poststroke epilepsy, respectively. Rapid declines in valproic acid concentrations were observed both times after meropenem administration. No seizures occurred in the first treatment period; however, when the patient suffered pneumonia again 3 months later, the same concomitant therapy was prescribed, and seizures occurred. It is difficult to identify a single etiology of the seizures. Based on a score of 7 on the Naranjo adverse drug reaction probability scale, the seizures were considered to be probably related to the concomitant administration of meropenem and valproic acid.

CONCLUSIONS

Various factors make the effect of concomitant administration of meropenem and valproic acid unpredictable, even in the same patient. Caution should be used when administering meropenem and valproic acid concomitantly, especially in elderly patients with central nervous system disorders, even if the patient has had a successful prior experience with these 2 drugs. If concomitant administration is essential, very close serum concentration monitoring and clinical observation are necessary.