Article Topic August, 1998 Seizures At Sea

As a greater percentage of people are enjoying the open sea whether as a cruise passenger or as a crew member of a sailing vessel. We will be encountering the possibility of managing a possible seizure. It is estimated that 10% of the population will have a seizure at some time during their lives possibly on your vessel. Additionally 1% of the population suffers from epilepsy. Your best approach to on-board medical care is understanding what seizures are how they relate to epilepsy and how to best treat or care for such a patient under your care. Seizures are often very frightening to on-board medical personnel.

Types of Seizures:

The generalized convulsive seizure is the most common seizure seen. Also called generalized tonic-clonic (GTC) or grand mal seizures, generalized convulsive seizures can also be purely tonic (stiff) or clonic (jerking) or clonic-tonic-clonic. Generalized seizures involve the whole brain.

Partial or localization-related seizures are seizures that arise from a specific part of the brain. The most common partial seizure involves the temporal lube seizure.

Epilepsy and Seizures:

Epilepsy is just one cause of seizures. In fact, only about 50% of seizures are due to epilepsy. Epilepsy is a disorder characterized by recurrent seizures which are not the result of a specific, immediate insult to the brain, such as alcohol withdrawal, drug intoxication or a low serum sodium. Such seizures are termed reactive seizures.

Remember Your ABCs:

As with all patients, the first step is dealing with patients with seizures is assessment and treatment of airway problems, breathing and circulation. The airway is frequently obstructed during GTC seizures. This is due to obstruction of the pharynx by the tonic activity of the muscles in that area during the seizure and due to complete loss of tone in these same muscles in the postictal. It is not due to patients "swallowing their tongue" – an unfortunate popular belief that may lead witnesses to try to insert something into the patient’s mouth, thereby causing injury, such as breaking a tooth.

Assuming that the airway is not obstructed, we can focus our attention on establishing breathing. Attempts to ventilate the patient during a seizure can prove to be futile. If assistance is needed, the use of high-flow oxygen should be placed using either a nasal cannula or a mask. The nasal cannula is usually better tolerated when the patient awakens after the seizure.

In reference to the question of circulation, the pulse and blood pressure usually rise significantly during a convulsive seizure, but return to normal quickly after the end of the seizure and usually do not require treatment. Occasionally, patients may become bradycardic or hypotensive, (low blood pressure) particularly after a prolonged seizure and this may require treatment with IV fluids or atropine.

Patient Evaluation:

Always carefully examine the patient for evidence of head injury or serious injury to any other part of the body fractures, lacerations, bruises and shoulders dislocation are seen in approximately 14% of patients and death in another 1% as a result of GTC seizures.

Look for a medic-alert bracelet or necklace as this may confirm a history of epilepsy or indicate other disorders that may have caused the seizure. Is there any evidence of drug abuse such as track marks or white powder in the nose? Is there any drug paraphernalia in the area?

Patient History:

Getting a detailed history from any witnesses is of critical importance in evaluating seizures. Does the patient have a history of epilepsy? How often does the patient have seizures? Was this one typical? If the patient is epileptic, do family and friends indicate that he may have been taking prescribed anticonvulsant medications? Does the patient have any other medical problems him or her to seizures, such as diabetes? Is the patient taking any medication, such as insulin, that might cause a seizure? Is there anything to suggest that the patient may have taken an overdose of medication, particularly a tricyclic antidepressant like amitriptyline (Elavil) or desipramine (Norpramin)? Does the patient drink alcohol or use illicit drugs? If the patient drinks alcohol, has he recently cut down or stopped drinking, leading to withdrawal seizures? A possible situation for a crew member who is forced by circumstance to suddenly cease consuming alcohol. Has the patient suffered a significant (with a loss of consciousness) head injury recently or in the past. Of particular interest is the question of how the seizure function started. Did the seizure start with a sudden, severe headache, raising the possibility of intracranial bleeding, such as a subarachnoid hemmorhage, as the cause of the seizure? A more prolonged, progressive headache may be associated with meningitis, a brain abscess or a tumor as the cause of the seizure.

Care At Sea:

As noted above, care of the seizure patient begins with the ABCs (See Table I). Most often, this is all that will be necessary, as most seizures last two or three minutes. If the seizure lasts for more than five minutes, institute specific treatment for the seizure, as seizures lasting more than five minutes have a much greater chance of going onto status epilepticus.

Table I: At Sea Prehospital Care of Seizures

• ABCs
• Check blood sugar
• If seizure lasts more than 5 minutes, IV diazepam or lorazepam (see text for dosages)
• Evaluate patient for injuries
• Detailed decription of the seizure and postictal state, particularly lateralized signs
• Detail history looking for causes of seizure (e.g., history of epilepsy, diabetes, drugs or alcohol abuse)
• Transport to hospital (see text)

Status epilepticus is defined as a seizure lasting more than 20 (some say 30) minutes or repetitive seizures without return to the patient’s normal mental state between seizure. Status epilepticus is a true medical emergency, with a mortality of up to 15%. The drugs of choice to treat a prolonged seizure or status epilepticus in the field are the benzodiazepines (valium or lorazepam). Both drugs are equally effective, but lorezpam (ativan) has the advantage of a longer functional half-life in the brain. The standard dosage of diazepam is up to 0.25 mg/Kg given no faster than 5 mg/min, while that of lorezepam is up to 0.1 mg/Kg given no faster than 2 mg/min intravenously. For adults, I usually recommend to give diazepam 5 mg or lorazepam 2 mg over one minute, then wait one or two minutes to observe its effect before giving the next dose.

If intravenous access is impossible, there are several alternative routes. Both drugs may be given intraosseously (within a bone) in young children or rectally in children or adults. There is now a premade kit for giving rectal diazepam (Diastat). Diazepam is very poorly absorbed and irritating to the tissues if given intramuscularly, so this should never be done. Lorazepam is better absorbed and not irritating to the tissues, but the absorption is too slow to be useful in an emergency situation. Midazolam (Versed) is being used in some countries for the treatment of status epilepticus. Its advantage is that it is rapidly absorbed intramuscularly and also can be given intravenously, rectally and intranasally. The other new drug, which may eventually find its way on to ships is fosphenytoin (Cerebyx). This is a pro-drug of phenytoin (Dilantin). It has the advantages of being able to be given significantly faster than IV phenytoin with fewer side effects such as hypotension and cardiac arrhythmias, and it may be given IM, although absorption IM is probably too slow to make it of use except in situations with prolonged transport times. The other advantage of fosphenytoin is that it does not alter the level of consciousness.

Diazepam and lorazepam should be used for the treatment of prolonged (longer than 5 minutes) or recurrent seizures only.

Seizure in young children:

Approximately 6% of children may have one or more febrile seizures. Simple febrile seizures occur between the ages of three months and six years. Simple febrile seizures require no specific treatment. The child may require cooling measures and should be evaluated in the emergency department to rule out a serious cause such as meningitis. Prolonged seizures will require treatment with diazepam or lorazepam, with particular attention being paid to the possibility of respiratory depression.

Transport to a Hospital:

Patients with known epilepsy who have had a single GTC seizure or simple or complex partial seizure do not require transport to the ED unless 1) this was not one of the patient’s typical seizures; 2) they have significant injuries; or 3) the patient’s mental status has not returned to baseline. Patients who have had their first seizure of any type, who have had multiple seizures, or who are pregnant should be transported.

Summary:

Seizures are a frequent problem confronting maritime medical personnel. Most seizures will terminate by themselves in less than five minutes. Careful attention must be paid to the ABCs, including glucose. Seizures lasting more than five minutes should be treated with IV or rectal diazepam or lorezepam. Careful history-taking to look for possible causes of seizures, as well as a detailed description of the event, are invaluable to medical advisory personnel in the evaluation and treatment of a patient with a seizure. Patients with known epilepsy who have had a single typical seizure and are otherwise back to normal do not require transport to the hospital. A detailed prevoyage medical history and possible physical are excellent methods for reducing the possibility of this unexpected medical problem.

Safe Travels!

Domenic A. Sammarco, R.Ph., EMT

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