AT AES 2014
SEATTLE (FRONTLINE MEDICAL NEWS) – Nearly a third of patients who experience a generalized convulsive seizure develop pulmonary edema, suggests a small cohort study reported at the annual meeting of the American Epilepsy Society. The longer the seizure lasts, the higher the probability of this complication.
“There are a few theories about how pulmonary edema can develop” in this context, noted first author Dr. Jeffrey Kennedy of the UC Davis Health System in Sacramento, Calif. Neurogenic mechanisms, hypoxemia, and prolonged negative intrathoracic pressure have all been implicated.
As far as the clinical implications, “postictal pulmonary edema may play a role in the mechanisms of SUDEP (sudden unexpected death in epilepsy),” he proposed at the annual meeting of the American Epilepsy Society.
Session attendee Dr. Kevin Chapman of the child neurology section in the department of pediatrics at Children’s Hospital Colorado, Aurora, asked, “If you identify somebody who has pulmonary edema, what do you do with them?”
“We have been following the patients who are clinically stable,” Dr. Kennedy replied. “We had a patient we identified with Takotsubo cardiomyopathy, which triggered some additional patient care from our cardiology department.”
“I think it just identifies patients who are at higher risk” for poor outcomes, he speculated. “In the EMU [epilepsy monitoring unit], when it comes to letting patients have more seizures, it does make us conservative as far as restarting medications and maybe trying to start giving them some benzodiazepines to try to shut things down.”
Another attendee commented, “Some of my patients’ relatives are very alarmed when the patient suffers severe cyanosis after a seizure. The first thing that our emergency staff will do when they arrive will be to clasp an oxygen mask over them. So our patients ask us, ‘Please, will we provide them with oxygen?’ I have a sneaking suspicion from your data that they may be justified in that. What would you advise?”
Another study done by the UC Davis group looked at a variety of peri-ictal interventions and found simple nursing practices worked about as well as oxygen, according to Dr. Kennedy ( Epilepsia 2013;54:377-82 ). “It seems like just doing something – stimulating the patient, turning them on their side – is enough, rather than just administering oxygen.”
In an interview, session comoderator Dr. Amy Crepeau, a neurologist at the Mayo Clinic Arizona in Phoenix, said the observed incidence of pulmonary edema raises important questions: “Is this something we need to be more conscientious about and really intervene more closely? Should we be shortening the duration of time before we stop seizures and not letting them go as long? It seems as though they have done that at UC Davis – kind of limited the number of seizures that they allow patients to have in the epilepsy monitoring unit.”
“This study comes back to this issue of who’s at risk for SUDEP, what are the causes for SUDEP, and what are the interventions we can use to try to prevent that or lessen the risk for it,” she added. “We are looking forward to seeing whether these patients have any increased risk of SUDEP that associates with the pulmonary edema.”
Dr. Kennedy and colleagues studied 24 consecutive adult patients, mean age 32, who experienced generalized convulsive seizures while undergoing monitoring in the UC Davis EMU, where all patients with such seizures receive a chest x-ray soon afterward as a safety measure.
Overall, 29% of the patients were found to have pulmonary edema, with or without focal infiltrates, on their chest x-ray, and another 17% were found to have focal infiltrates only.
The mean time elapsed between the seizure and the chest x-ray acquisition was 225 minutes in the patients with abnormal findings and 196 minutes in the patients with normal findings, a nonsignificant difference, reported Dr. Kennedy, who disclosed that he had no relevant conflicts of interest.
The seizure duration was more than twice as long among patients with chest x-ray abnormalities as among counterparts without these abnormalities (250 vs. 101 seconds; P = .002), and the probability of abnormalities increased with seizure duration.
The groups with and without chest x-rays abnormalities did not differ significantly with respect to a variety of demographic and cardiorespiratory and other clinical factors, however.