Paramedics attend patients who are having a seizure on almost a daily basis. Consequently, paramedics should understand the disease processes related to seizures and be confident in their prehospital management. In general, with the exception of a patient in Status Epilepticus, seizure management should be relatively straight forward.
So, what is a seizure and what causes it? Basically, a seizure is any unusually excessive neuronal firing from the brain which manifests as changes in a patient’s motor/sensory control, sensory perception, behaviour and autonomic function.
At a chemical level a seizure occurs when there is a sudden biochemical imbalance between the excitatory neurotransmitters and inhibitory neurotransmitters. The primary excitatory neurotransmitter found in the human central nervous system is called N-Methyl D Aspartate (NMDA); whereas the primary inhibitory neurotransmitter is called gamma-amino butyric acid (GABA). When there is an imbalance between these chemical mediators repeated firing and excitations of the neuronal cells occur. Depending on the area of the brain in which this occurs, the seizure will manifest as a focal seizure, sensory change, behaviour disturbance, or complete tonic and clonic muscular activity.
Paramedic Assessment and Treatment of Seizures
As a paramedic these are the steps that I take to assess and treat a patient who is having a seizure or is post ictal:
1. Position the patient on their side and remove any dangerous items from the patient. If the patient is sitting, try to assist him or her to the floor. The safest place for a person who is having a seizure is on the floor or in a bed with rails so that they are unable to fall any further and injure themselves. I try to get a pillow (if possible) to place underneath their head and keep their airway naturally open. Don’t try to place anything in their mouth to protect them from biting their tongue. It won’t help and is only likely to cause more harm.
2. Reassure their family members or bystanders. Anyone who has witnessed a seizure for the first time will understand just how frightening it can be. Particularly if you are treating a child and their parents have never seen a seizure.
3. Assess the patient’s airway for patency and respiratory rate. Most people who have seizures have only very short periods of apnoea, but some may have prolonged periods. Normally, the airway can be protected by laying them on their side and if required a nasopharyngeal airway can be inserted (but shouldn’t be required in all patients).
4. Benzodiazepines have been used as the mainstay emergency treatment of seizures. IM or IV midazolam is generally very successful in control seizure activity. Benzodiazepines increase the activity of GABA by binding to the benzodiazepine site on the GABA – A receptors, which potentiates the effects of GABA by increasing the frequency of the chloride channel opening and causing an inhibitory response in the CNS.
5. Gain an accurate seizure specific history of the patient. Ask questions such as:
– Does the patient have epilepsy?
– When was his or her last seizure?
– Did he or she take their anti-epilepsy medication today?
– Has there been any recent changes such as illness?
– Has there been any traumas to the head, such as recent falls or direct hit to the head?
– What was the seizure like today? Was it the normal presentation for this person, or was it different? If so, how so?
– Does the patient normally have subsequent seizures, or just the one?
– What type of seizure did the person have? Were there arms and legs shaking (tonic/clonic movements), or was it just a focal part of the body?
– Is the person a known alcoholic? Or, has the person been recently withdrawing from alcohol or benzodiazepine use?
6. Assess the patient thoroughly including an assessment of their: airway, breathing, circulation, disability, and exposure. Make sure to take their temperature and check their blood glucose level, because changes in either of these are known to causes seizure activity.
7. Provide oxygen therapy for all patients who appear to have had a seizure or who are having a seizure. As each cell becomes polarized and the subsequent muscles contract large amounts of oxygen is utilised.
8. IV access, where possible, should be gained prior to moving the patient, especially if the patient is known to have multiple seizures.
9. Perform a thorough head to toes assessment to check for any trauma caused prior to or as a result of the seizures. Check that the patient hasn’t bitten their tongue.
10 .Assess pupils for signs of a stroke, arm strengths, face symmetry and speech.
11. Make a mental note whether or not the patient has been incontinent of urine or faeces.
12. If this is their first seizure or they have epilepsy but have no clear cause for the seizure activity today, it is vital to transport them to hospital for further investigation.
For patients who have been diagnosed with epilepsy the most common cause of seizures are either sub therapeutic levels of anticonvulsant medications (most commonly the patient has been non-compliant in taking their medications) or there is a problem with the patient’s pharmacokinetics (such as a disturbance in their ability to absorb, distribute, metabolise or excrete the medication, most commonly seen during periods of infection).
In patients who have never previously been diagnosed with seizures the following are potential causes:
1. Alcohol or benzodiazepine withdrawal
2. Brain tumour or neoplasm
3. Traumatic head injury
5. Drug overdose or poisoning
6. Eclampsia (pregnancy related hypertension and seizure activity)
7. Metabolic disorders (primarily hypo or hyperglycaemias, but also hypo/hyper natraemia often associated with women who start crash diets involving the consumption of large amounts of water)
8. Infections (meningitis or encephalitis)
9. Drug use
10. Hyperthermia (most commonly febrile convulsions seen in children)
Whatever the cause of the seizure activity, it is important to treat the seizure early. The longer a seizure is allowed the last the greater the potential risk to the patient that they will become status epilepticus. Never leave a patient at home who has had their first seizure ever or an unexplained seizure.