Treatment of refractory complex-partial status epilepticus with propofol: case report

Continuous Infusion Antiepileptic Medications for Refractory Status Epilepticus: A Review for Nurses

Status epilepticus requires treatment with emergent initial therapy with a benzodiazepine and urgent control therapy with an additional antiepileptic drug (AED) to terminate clinical and/or electrographic seizure activity. However, nearly one-third of patients will prove refractory to the aforementioned therapies and are prone to a higher degree of neuronal injury, resistance to pharmacotherapy, and death. Current guidelines for refractory status epilepticus (RSE) recommend initiating a continuous intravenous (CIV) anesthetic over bolus dosing with a different AED. Continuous intravenous agents most commonly used for this indication include midazolam, propofol, and pentobarbital, but ketamine is an alternative option. Comparative studies illustrating the optimal agent are lacking, and selection is often based on adverse effect profiles and patient-specific factors. In addition, dosing and titration are largely based on small studies and expert opinion with continuous electroencephalogram monitoring used to guide intensity and duration of treatment. Nonetheless, the doses required to halt seizure activity are likely to produce profound adverse effects that clinicians should anticipate and combat. The purpose of this review was to summarize the available RSE literature focusing on CIV midazolam, pentobarbital, propofol, and ketamine, and to serve as a primer for nurses providing care to these patients.

Critical care sedation for neuroscience patients

In 2000, the Joint Commission on Accreditation of Healthcare Organizations (JCAHO) introduced the mandate for the implementation of standards for both pain assessment and need for therapy in hospitalized patients. The need for the appropriate titration of sedation and analgesia is particularly poignant in an intensive care unit (ICU) setting where iatrogenic discomfort often complicates patient management. Neurologically ill patients in ICUs present particularly complex sedation issues, owing to the need to monitor these patients with serial neurological exams. Hence, maximal comfort without diminishing neurological responsiveness is desirable. Here, we review the frequently applied methods of evaluating levels of pain and agitation in critically ill patients as well as discuss the appropriate classes of pharmaceutical agents common to this population, with particular emphasis on the potential neurophysiological impact of such therapy.

Comparative Efficacy and Safety of Antiepileptic Drugs for the Treatment of Status Epilepticus

Status epilepticus (SE) is a medical emergency with high mortality rate. Common causes of SE include noncompliance with antiepileptic medications, drug- and alcohol-related etiologies, and central nervous system (CNS) infections. Because prolonged seizures can cause neuronal damage, treatment should be initiated promptly to avoid potential complications. Previous studies support intravenous (IV) lorazepam as first-line therapy and IV phenytoin or fosphenytoin as a second-line medication. If first-and second-line medications fail to control SE, further treatment with propofol, pentobarbital, midazolam, or other medications should be considered. Many of the drugs currently used to control SE are associated with sedation, respiratory suppression, hypotension, cardiac dysrhythmia, and anaphylactic reactions. Therefore, IV valproate or other newer antiepileptic drugs may be considered as an alternative third-line therapy for those who cannot tolerate the hypotensive effects of other anticonvulsants. This paper reviews comparative effectiveness and safety concerns among frequently used medications for SE.

Nonconvulsive status epilepticus causing prolonged stupor after intraventricular hemorrhage: report of a case

We describe the case of an octogenarian woman who experienced a severe alteration of mental state due to non-convulsive status epilepticus (NCSE) complicating an intraventricular hemorrhage. Our report emphasizes that NCSE may be the cause of unexplained neurological deterioration in elderly patients with acute brain injury.

[Refractory status epilepticus: diagnosis, therapy, course, and prognosis]

Status epilepticus (SE) is a frequent neurological emergency with an annual incidence of 10-20/100,000 individuals. The overall mortality is about 10-20%. Patients present with long-lasting fits or series of epileptic seizures or extended stupor and coma. Furthermore, patients with SE can suffer from a number of systemic complications possibly also due to side effects of the medical treatment. In the beginning, standardized treatment algorithms can successfully stop most SE. A minority of SE cases prove however to be refractory against the initial treatment and require intensified pharmacologic intervention with nonsedating anticonvulsive drugs or anesthetics. In some partial SE, nonpharmacological approaches (e.g., epilepsy surgery) have been used successfully. This paper reviews scientific evidence of the diagnostic approach, therapeutic options, and course of refractory SE, including nonpharmacological treatment.

Animal models for the development of new neuropharmacological therapeutics in the status epilepticus

Status epilepticus (SE) is a major medical emergency associated with significant morbidity and mortality. SE is best defined as a continuous, generalized, convulsive seizure lasting > 5 min, or two or more seizures during which the patient does not return to baseline consciousness. The relative efficacy and safety of different drugs in the treatment of human SE should be determined in a prospective, randomized, blinded study. However, complementary animal models of SE are required to answer important questions concerning the treatment of SE because of the obvious difficulties of setting up such studies in clinical emergency conditions. This review offers an overview of the implementation and characteristics of some of the most prevalent animal models of SE currently in use. A description is also provide about how animal models of SE may facilitate the use of neurobiological techniques to successfully address critical questions in the drug treatment of SE. In particular, the experience with recently introduced drugs such as intravenous valproate will be addressed. Finally, the importance of some animal models and pharmacological approaches is explained and we discuss their impact in the development of therapeutic strategies to improve pharmacological treatment for SE is discussed.

Propofol treatment of refractory status epilepticus: a study of 31 episodes

PURPOSE

Refractory status epilepticus (RSE) is a critical medical condition with high mortality. Although propofol (PRO) is considered an alternative treatment to barbiturates for the management of RSE, only limited data are available. The aim of this study was to assess PRO effectiveness in patients with RSE.

METHODS

We retrospectively considered all consecutive patients with RSE admitted to the medical intensive care unit (ICU) between 1997 and 2002 treated with PRO for induction of EEG-monitored burst suppression. Subjects with anoxic encephalopathy showing pathological N20 on somatosensory evoked potentials were excluded.

RESULTS

We studied 31 RSE episodes in 27 adults (16 men, 11 women; median age, 41.5 years). All patients received PRO, and six also subsequently thiopental (THP). Clonazepam (CZP) was administered with PRO, and other antiepileptic drugs (AEDs) concomitant with PRO and THP. RSE was successfully treated with PRO in 21 (67%) episodes and with THP after PRO in three (10%). Median PRO injection rate was 4.8 mg/kg/h (range, 2.1-13), median duration of PRO treatment was 3 days (range, 1-9), and median duration of ICU stay was 7 days (range, 2-42). In 24 episodes in which the patient survived, shivering after general anesthesia was seen in 10 episodes, transient dystonia and hyperlipemia in one each, and mild neuropsychological impairment in five. The seven deaths were not directly related to PRO use.

CONCLUSIONS

PRO administered with CZP was effective in controlling most of RSE episodes, without major adverse effects. In this setting, PRO may therefore represent a valuable alternative to barbiturates. A randomized trial with these drug classes could definitively assess their respective role in RSE treatment.

Pharmacology and pharmacokinetics of sedatives and analgesics

The agents used for sedation and analgesia during endoscopy have complex pharmacokinetic and pharmacodynamic properties. Knowledge of these characteristics is necessary for determining the proper agent and dose for specific patient needs. Short-acting agents, such as fentanyl, midazolam, and propofol, provide rapid sedation with a short duration of action that allows patients to return to normal functioning rapidly. When designing a dosing regimen with these agents, age and organ (liver, kidney) function of patients and concomitant medications that may interfere with metabolic and elimination pathways must be considered.

Comparison of conscious sedation and general anesthesia for motor mapping and resection of tumors located near motor cortex

Object

The surgical treatment of tumors located near eloquent cortex carries a high risk of inducing worsening neurological deficits. Intraoperative electrocorticography techniques have been developed to help identify these areas at the time of surgery in an effort to minimize such risks. The optimal anesthetic technique for conducting these procedures, however, has never been determined.

Methods

The authors conducted a retrospective study to compare patients who underwent intraoperative motor mapping between September 2000 and May 2002. Demographic and neurophysiological monitoring data were collected from the hospital records. Patients were divided into two groups based on the anesthetic technique used for surgery: in Group 1 general anesthesia was used, and in Group 2 conscious sedation.

Group 1 comprised 24 patients (mean age 47 years) with 16 right- and eight left-sided lesions. Group 2 consisted of 21 patients (mean age 46 years) with 18 right- and three left-sided lesions. Pathological diagnoses were similar between the two groups. Motor stimulation was elicited in 12 patients (50%) in Group 1 and in 21 patients (100%) in Group 2 (p < 0.001). In addition, the mean stimulation amplitude required was significantly higher (13 mA) in patients in whom conscious sedation was used as opposed to general anesthesia (5 mA, p < 0.0001). Electrographic evidence of seizures was seen in 29% of Group 1 cmpared with 10% of Group 2 patients (p > 0.05).

Conclusions

The use of conscious sedation as an anesthetic technique for motor mapping not only improves the chances of achieving successful stimulation and identification of motor cortex in relationship to the lesion, but it also allows for repetitive monitoring of the patient's motor function during resection of the lesion.

Barbiturates for acute neurological and neurosurgical emergencies--do they still have a role?

A number of clinical studies have reported poor clinical outcomes for patients treated with barbiturate therapy in acute neurological and neurosurgical emergencies. Barbiturate therapy, as currently practised with thiopentone and pentobarbitone at least, is also associated with a prolonged post-infusion period of clinical unresponsiveness. Hence, the popularity of barbiturate therapy for sedation of critically ill neurological and neurosurgical patients has declined over the past decade. A retrospective study of traumatic brain injury patients treated at the Royal North Shore Hospital, Sydney, with high-dose thiopentone therapy between 1987 and 1997 has found disappointing results with a 1-month mortality outcome of 50% (14 of 28 patients). Nevertheless, barbiturate therapy remains a consideration for patients with severe cranial trauma in whom preferred treatments have failed to control intracranial or cerebral perfusion pressures. More favourable results ( approximately 10% 1-month mortality rate) were encountered for patients with refractory vasospasm complicating subarachnoid haemorrhage or intracerebral haemorrhage complicating supratentorial arteriovenous malformation resection. A well designed, prospective and randomised controlled trial may be of value in further determining the role of barbiturate therapy in acute neurovascular emergencies refractory to standard therapy.

Diagnosis and Treatment of Nonconvulsive Status Epilepticus in an Intensive Care Unit Setting

Nonconvulsive status epilepticus (NCSE) in adults is a heterogeneous epileptic emergency and includes absence status (AS), complex-partial status epilepticus (CPSE), and the status epilepticus of epileptic encephalopathy (SEEE). The latter seems to be strikingly frequent among patients in intensive care units (ICU). Diagnosis of NCSE is difficult, but has to be made quickly. It relies on clinical signs and a confirmation electroencephalography (EEG). According to the different etiologies and outcomes of AS, CPSE, and SEEE, treatment has to be individually adapted, but needs to follow some basic principles--treatment should take place in the ICU and be monitored by continuous EEG. With a few exceptions, the first drug is an intravenous benzodiazepine, mainly lorazepam. Intravenous fosphenytoin or phenytoin or valproate may follow next. If some forms of NCSE are resistant to first- and second-line treatments, single or combinations of anesthetics and enteral antiepileptic drugs (AEDs) may be added. This opinion is not evidence-based, and randomized controlled prospective trials to evaluate optimal treatment of NCSE are of first priority.

Treatment of refractory status epilepticus with pentobarbital, propofol, or midazolam: a systematic review

BACKGROUND

New continuous infusion antiepileptic drugs (cIV-AEDs) offer alternatives to pentobarbital for the treatment of refractory status epilepticus (RSE). However, no prospective randomized studies have evaluated the treatment of RSE. This systematic review compares the efficacy of midazolam (MDL), propofol (PRO), and pentobarbital (PTB) for terminating seizures and improving outcome in RSE patients.

METHODS

We performed a literature search of studies describing the use of MDL, PRO, or PTB for the treatment of RSE published between January 1970 and September 2001, by using MEDLINE, OVID, and manually searched bibliographies. We included peer-reviewed studies of adult patients with SE refractory to at least two standard AEDs. Main outcome measures were the frequency of immediate treatment failure (clinical or electrographic seizures occurring 1 to 6 h after starting cIV-AED therapy) and mortality according to choice of agent and titration goal (cIV-AED titration to "seizure suppression" versus "EEG background suppression").

RESULTS

Twenty-eight studies describing a total of 193 patients fulfilled our selection criteria: MDL (n = 54), PRO (n = 33), and PTB (n = 106). Forty-eight percent of patients died, and mortality was not significantly associated with the choice of agent or titration goal. PTB was usually titrated to EEG background suppression by using intermittent EEG monitoring, whereas MDL and PRO were more often titrated to seizure suppression with continuous EEG monitoring. Compared with treatment with MDL or PRO, PTB treatment was associated with a lower frequency of short-term treatment failure (8 vs. 23%; p < 0.01), breakthrough seizures (12 vs. 42%; p < 0.001), and changes to a different cIV-AED (3 vs. 21%; p < 0.001), and a higher frequency of hypotension (systolic blood pressure <100 mm Hg; 77 vs. 34%; p < 0.001). Compared with seizure suppression (n = 59), titration of treatment to EEG background suppression (n = 87) was associated with a lower frequency of breakthrough seizures (4 vs. 53%; p < 0.001) and a higher frequency of hypotension (76 vs. 29%; p < 0.001).

CONCLUSIONS

Despite the inherent limitations of a systematic review, our results suggest that treatment with PTB, or any cIV-AED infusion to attain EEG background suppression, may be more effective than other strategies for treating RSE. However, these interventions also were associated with an increased frequency of hypotension, and no effect on mortality was seen. A prospective randomized trial comparing different agents and titration goals for RSE with obligatory continuous EEG monitoring is needed.

Clinical review: status epilepticus

Status epilepticus (SE) has an annual incidence exceeding 100,000 cases in the United States alone, of which more than 20% result in death. Thus, increased awareness of presentation, etiologies, and treatment of SE is essential in the practice of critical care medicine. This review discusses current definitions of SE, as well as its clinical presentation and classification. The recent literature on epidemiology is reviewed, including morbidity and mortality data. An overview of the systemic pathophysiologic effects of SE is presented. Finally, significant studies on the treatment of acute SE and refractory SE are reviewed, including the use of anticonvulsants, such as benzodiazepines, and other drugs.

Intravenous valproate in status epilepticus

OBJECTIVE

To evaluate the role of intravenous valproate sodium (IV VPA) in the treatment of status epilepticus (SE).

DATA SOURCES

A literature search of the English language was performed (MEDLINE 1966-July 2000). Search terms included valproate, valproic acid, and status epilepticus. Bibliographies of articles chosen were reviewed to identify other possible sources.

DATA SYNTHESIS

A review of the medical literature was conducted to evaluate the safety and efficacy of IV VPA in the treatment of SE.

CONCLUSIONS

Experience with IV VPA in the treatment of SE is too limited to recommend its use as a first-line agent. IV VPA may represent a third- or fourth-line option in cases of SE when other agents are ineffective or contraindicated.

Therapy of status epilepticus in adults and children

Clinical studies of the treatment of status epilepticus are extremely difficult to carry out, therefore a paucity of new clinical studies have been reported. Much of the progress regarding the therapy of status epilepticus has come from a better understanding of the epidemiology of status epilepticus and its consequences and from laboratory studies of experimental status. Status epilepticus has been used as an experimental tool to study epileptogenesis, but from such studies have come insights that can be applied to the therapy of status epilepticus itself. This review will focus on information from epidemiological, experimental, and clinical studies of status epilepticus, which may contribute to the improved treatment of this life-threatening disorder.

[Epileptogenic drugs in anesthesia]

Most anaesthetics and analgesics have both pro- and anticonvulsant activity. The data in the literature should be analysed with respect to the patient population, the recording of epileptic activity and the method of EEG analysis. Among inhaled anaesthetics, isoflurane has strong anticonvulsant properties. In some circumstances, sevoflurane may induce an epileptic activity. With the exception of ketamine and etomidate, all intravenous hypnotics may be used for anesthesia of the epileptic patient. Midazolam is a potent anticonvulsant. Among narcotics, fentanyl and alfentanil may induce clinical or electroencephalographic seizures. Considering the large number of patients treated with these agents without any neurological adverse effect, the clinical relevance of these data is unclear. Neuromuscular blocking agents do not possess pro- or anticonvulsant properties.

[Anesthesia for epilepsy surgery]

Epilepsy is rather common, affecting 0.5 to 2% of the population. Numerous patients, particularly those resistant to the antiepileptic therapy, can be surgically treated after a thorough evaluation. Surgery for epilepsy can be carried out either under general or local anaesthesia with sedation. This second approach is reserved for the extirpation of foci localised in motor, sensory or language areas. During the preoperative anaesthetic evaluation, two specific points have to be taken into account: the psychological aspect and the antiepileptic medication. During the procedure, an electrocorticography with or without stimulation may be indicated, particularly when a perioperative stimulation is scheduled. Low doses of volatile agents are chosen, and no curare and large doses of benzodiazepines and barbiturates. Awakening takes place on the operation table for a rapid and reliable neurological evaluation. During procedures performed under local anaesthesia, the anaesthetist must be ready at any time to intubate the patient in order to secure the airway.