A general discussion of the diagnosis and treatment of seizure disorder is beyond the scope of this book. This chapter focuses on the considerations of airway management in the seizure patient. In the simple, self-limited, generalized seizure, airway management is directed at termination of the seizure and prevention of hypoxia from airway obstruction. Paralysis and intubation should be considered when SpO₂ declines <90% or when typical first-line measures fail to terminate the seizure in a reasonable time. For the simple seizure, basic airway maneuvers, expectant observation (most seizures end spontaneously), supplemental high-flow oxygen, and vigilance are usually all that is necessary. Airway protection from aspiration is rarely required in the simple, self-limited seizure because the uncoordinated motor activity precludes coordinated expulsion of gastric contents.

Determining when to proceed from supportive measures to intubation is the main clinical challenge in the airway management of the seizing patient. Status epilepticus has been defined as continuous seizure activity for 30 minutes or multiple seizures without recovery of consciousness in between. The rationale for 30 minutes was that this is the minimum seizure duration that has been believed to produce neuronal injury. Recent literature questions the practical value of this, and it has been proposed that the “operational definition” of generalized convulsive status epilepticus in adults and children >5 years be modified to 5 minutes or more of continuous seizure activity. The intended implication of this change is that clinicians wait no longer than 5 minutes of continuous seizure activity before initiating therapy to terminate seizure activity. Any seizure lasting longer than 5 minutes is concerning because most single seizures are much shorter in duration than this. The brain’s compensatory mechanisms to prevent neuronal damage rely on adequate oxygenation and cerebral blood flow, and brain compensation is often compromised before 30 minutes, particularly in patients with underlying illness. There is also evidence that with longer seizure duration, pharmacologic therapies become less effective. The mortality rate for status epilepticus is >20% and also increases with duration of seizure activity. Therefore, intubation should be undertaken early as a part of overall supportive therapy in cases where the seizure is not promptly terminated by anticonvulsant medications begun at a seizure duration of not >5 minutes. The absolute and relative indications for intubation in the seizing patient are listed in Box 37-1.

RSI is the method of choice in the seizing patient. In addition to its technical superiority, RSI ends all motor activity, allowing the body to begin to correct the metabolic debt. However, cessation of motor activity while the patient is paralyzed does not represent termination of the seizure, and effective loading doses of appropriate anticonvulsants (e.g., phenytoin) are required immediately after intubation. The recommended technique for the seizure patient is described in Box 37-2. Standard RSI technique is appropriate in the seizing patient with the following modifications: