Diazepam (Valium) 0.2–0.3 mg/kg IV over 2–5 minutes (max. 10 mg) ‐OR‐ 0.5 mg/kg per rectum
Note: See text for details of alternative dosing regimens. Respiratory depression is the most serious side effect and is likely related to rate of administration.
Generally, IV administration of benzodiazepines has been the standard because of rapid therapeutic drug levels, but a variety of reports substantiates the effectiveness of intramuscular, rectal, nasal, and buccal administration of different agents. Benzodiazepines are well tolerated, with primary side effects of sedation and respiratory depression. The respiratory depression seems to be related to time to peak serum concentration. Somewhat paradoxically, the IV route may offer the quickest time to peak concentrations but at a risk of greater respiratory depression.
The use of alternative routes is particularly attractive in the pediatric population. Intraosseous administration should be an effective route of administration, but it has been little studied in seizure patients.
Rectal administration of benzodiazepines (particularly diazepam) for status epilepticus in children has been reported for years [33]. Studied dosages are 0.5 mg/kg administered using a syringe and a soft catheter. Correction should be made for the volume left in the catheter. A second dose of 0.25 mg/kg may be administered if needed. It is generally thought that rectal administration results in peak plasma levels within 10 minutes. A preparation approved by the US Food and Drug Administration, Diastat, is available [34].
Nasal administration of benzodiazepines (usually midazolam) has been reported in small case series [35]. Ease of use was the focus in studies comparing nasal midazolam with IV diazepam [36]. Time to seizure cessation was comparable. Another report compared intranasal administration of midazolam using an atomizer device with rectal diazepam and found better seizure control and fewer respiratory complications in the group treated with intranasal midazolam [37].
Buccal midazolam has been studied for seizure control in children in the ED, in comparison with rectal diazepam, and has been found to be as effective or more effective without increased risk of respiratory depression [38, 39]. Dosages administered were 0.25 mg/kg or 0.5 mg/kg with adjustments by age, and a 10 mg maximum dosage for children age 10 or older. As with many of the therapies discussed here, this is off‐label usage. Buccal midazolam is advocated by some as a choice for initial management of prolonged seizures in children, although issues of dosing remain and further study is desirable [40, 41].
Intramuscular (IM) administration of a benzodiazepine is possible with midazolam, which has solubility characteristics favorable for absorption [42]. IM administration is rapid and aspiration is not a concern. Increased use of IM midazolam has been noted in some systems [43]. In one small series of children with seizures, comparing treatment with IM midazolam with IV diazepam, the former was found to be an effective alternative. Part of the efficacy was thought to be from the rapid administration possible by the IM route without having to establish IV access [44]. The RAMPART study established the safety and efficacy of IM midazolam compared to IV lorazepam when administered for prehospital status epilepticus [45]. Paramedics in this large, randomized, double‐blind trial administered midazolam intramuscularly using preloaded auto‐injectors. Advantages of the intramuscular route included more rapid drug administration. Dosages of midazolam were 10 mg IM for adults and children estimated to weigh more than 40 kg and 5 mg IM for children estimated to weigh 13–40 kg. Adverse events were similar in both groups. However, IV midazolam was found to be more effective than IM administration in one prehospital study, with minimal risk of respiratory depression in both groups [46].
Seizure‐associated trauma
In some EMS systems, patients who have experienced seizures are often secured to backboards to facilitate spinal motion restriction. There appears to be very limited evidence to support this practice, although trauma from seizures has been reported in case reports, case series, and retrospective reviews.
Seizures uncommonly cause fractures and dislocations. Some uncommon orthopedic injuries, such as bilateral posterior dislocation of the shoulder, fracture‐dislocation of the shoulder, or fracture‐dislocation of the hip, suggest a generalized convulsion as the etiology. Bilateral hip fractures have been reported [47]. These cases are notable for their rarity.
Only very rare cases of cervical fractures from uncomplicated seizures are reported. There is one description of an odontoid fracture following an epileptic seizure [48]. One retrospective study of over 1,600 transports for uncomplicated seizures (i.e., age greater than 5 years, no associated major trauma, afebrile) found no spinal fractures. Transport charges and nursing charges were higher in the group with spinal immobilization. The authors raised the question of the need for full spinal precautions in patients sustaining uncomplicated seizures [49]. Compression fractures of the thoracic vertebrae were reported in a patient taking steroids [50]. There is one report of a higher risk of cervical spinal cord injuries in patients with refractory epilepsy attributed to seizure‐related falls. This residential facility for patients with refractory epilepsy reported four instances of spinal cord injuries in its patient population over 10 years, which they extrapolated to be a 30‐fold to 40‐fold risk increase [51].
Retrospective chart reviews of patients with seizures have also identified patients with intracranial hematomas resulting from falls associated with seizures. The authors advocate early investigation in patients with head injury due to seizures and caution that decreases in level of consciousness or focal neurologic deficits in seizure patients should only cautiously be interpreted as postictal until traumatic hematomas have been excluded [52]. This review undoubtedly incorporates significant ascertainment bias, as it was from a neurosurgical service.
Given the paucity of reports of significant trauma following uncomplicated seizures, routine use of backboards in attempts to achieve spinal immobilization is not warranted. However, EMS clinicians should be aware that unusual injuries can occur. They must also be alert to historical features or physical findings that indicate potential injuries.
Continuing management
Continued patient management in the ED is influenced by what occurred in the field. If the patient’s condition does not evolve to an alert state, the degree of unresponsiveness should be continuously monitored as evaluation proceeds along the pattern of primary survey, resuscitation, secondary survey, and definitive care steps. Information from EMS personnel regarding level of alertness in the field is helpful.
Should the need for a definitive airway be established, rapid sequence intubation is performed in the usual manner, and this is a field option for some paramedics and EMS physicians. Concerns for possible increased intracranial pressure, if suspected from history or physical examination, may prompt consideration for lidocaine administration as part of rapid sequence intubation, although this remains controversial. Most induction agents have some anticonvulsant properties and use of benzodiazepines would seem prudent, although data are lacking to support these actions. The use of short‐acting paralytic agents, if necessary, should proceed in the usual manner [53]. There are only rare case reports in medically complex seizure patients of complications from succinylcholine [54]. Longer‐acting neuromuscular blockade should be avoided, however, unless EEG monitoring can be established, because of concerns that seizure activity may be disguised by neuromuscular paralysis.
Somnolent patients should be observed and monitored. The postictal state is not well defined, but the possibility of ongoing subclinical seizure activity, complex medical issues, or trauma should be considered if a seizure patient is not starting to become alert within approximately 30 minutes.
Refractory generalized convulsive status epilepticus
Detailed
