Myasthenia Gravis Hope Foundation

Myasthenia Gravis EMS Considerations and Triage

Not all Myasthenia Gravis patients will present with obvious symptoms, but may still be struggling with rapidly increasing flaccidity that can lead to critical respiratory distress with partial or total diaphragmatic paralyzation. Anxiety may be present but it is not the cause of Mysasthenic emergency. Do NOT assume the patient is exaggerating symptoms in what may appear to be a benign presentation. Myasthenics can rapidly decline within minutes.

Not addressing a Myasthenic in exacerbation or crisis appropriately can lead to fatality.

Do not rely on single criteria assessment. Evaluation should include:

Blood pressure and heart rate: In respiratory distress, tacychardia and hypertension can be present. (Please note, Mestinon can cause hypotension and bradycardia.)
Respirations: Dypsnea, tachypnea (compensation for weakened inspiratory muscles) and stridor may be present and exacerbated in the supine position which further weakens the diaphragm.
Speech quality: dysphonia, hypophonia, dysarthria, hyponasality and aphonia may be present, are part of bulbar weakness and connected to a flaccid diaphragm. Some patients have a predominance to bulbar weakness but it should always be considered a critical presentation in Myasthenics complaining of difficulty breathing or increasing systemic weakness.
Bulbar weakness: Dysphagia, sialorrhea, weak neck flexion and speech quality correlate to a flaccid and partially paralyzed diaphragm.
Check co2 with inspiratory flaccidity. Do not rely on osats for stability indicator.
MEP/MIP, NIF, FVC should be part of exhaustive evaluation. Do not use one test in isolation over the other. Difficulty for patient to maintain a good seal on NIF/FVC or inability to repeat attempts due to increasing flaccidity can factor into falsely stable numbers.
ABG is not always a reliable indicator as changes in arterial blood gases may not happen until after the patient is critical. Do not use as a single exclusion test.
Check contraindicated medication list before medicating.

Oxygen can be used on route to the closest emergency facility but is a bandaid and will not address Myasthenic respiratory weakness. Myasthenia Gravis respiratory distress is an issue of ventilatory failure and not oxygenation capability. The lung's tissue maintains it's ability to oxygenate during inspiratory paralyzation in the early stages and oxygen levels can remain falsely elevated. Oxygen supplementation can be used for temporary assistance and comfort. NIV support is preferable and can be used to help assist the diaphragm and potentially avoid mechanical ventilation, although ventilation may be required. Avoid muscle relaxers for intubation if possible.

Patient is not drunk and may be slurring due to bulbar weakness.
Please notify the MG specialist or treating physician on route to the hospital.
If you suspect exacerbation or crisis please check airway, inspiratory strength, neck flexion, speech quality, ability to clear secretions and swallowing.
Do not lay the patient supine as this increases diaphragm weakness. Lay in an elevated position or elevated to the side.
If the patient appears sleepy and is dyspniec or tacypenic, please check co2 for possible hypercapnia.
Please avoid muscle relaxers.
Patient may have predominance to respiratory flaccidity while maintaining reasonable levels of extremity and ocular strength.

A patient may be experiencing varying levels of diaphragmatic paralysis and have stable testing outcomes. These do not rule out advancing exacerbation or crisis. Changes and measurable data may not occur until AFTER the patient has crashed.

Maintain calm environment and appropriate ventilatory support. Do not wait for the patient to crash to seek NIV solutions.

Ice packs on the neck, throat and diaphragm can help provide slowed nerve transmission and offer partial, temporary relief. Use as appropriate. Ensure room temperature is also cool and comfortable to allay increased flaccidity.

Cholinergic Crisis Assessment:

SLUDGE syndrome may be helpful in rapid assessment. Both Myasthenic and Cholinergic crisis may see crossover in presentation but these two crisis are very different.

S : Salivation

L : Lacrimation

U : Urination

D : Diarrhea

G : GI Distress

E : Emesis

(M) : Miosis

Cholinergic crisis is an over-stimulation at a neuromuscular junction due to an excess of acetylcholine (ACh), as a result of the inactivity (perhaps even inhibition) of the AChE enzyme, which normally breaks down acetylcholine. Atropine can be used to help reverse Cholinergic crisis. Please assess patient for possible Cholinergic presentation:

Diaphoretic
Sialorrhea
Emesis
Diarrhea
Urination
Severe GI Distress
Sudden, pronounced weakness
Twitching (moderate to severe)

Contraindicated Medication List

Please read before medicating Myasthenic Patients

Note:

This list is meant to be a cautionary guide to facilitate safer care and better outcomes. No two patients will respond the same to even higher risk medications so it is imperative that you assess their unique needs and current presentation before making any changes.

Many different drugs have been associated with worsening myasthenia gravis (MG). However, these drug associations do not necessarily mean that a patient with MG should not be prescribed these medications because in many instances the reports are very rare and in some instances they might only be a “chance” association (i.e. not causal). Also some of these drugs may be necessary for a patient’s treatment. Therefore, some of these drugs should not necessarily be considered “off limits” for MG patients. Careful thought needs to go into decisions about prescription. It is advisable that patients and physicians recognize and discuss the possibility that a particular drug might worsen the patient’s MG and when available and appropriate, careful monitoring should take place.. It is strongly advised, when appropriate, the pros and cons of an alternate treatment, when available. Patients also have a responsibility to report any changes or worsening of their symptoms to their care teams. We are only listing the more common prescription drugs with the strongest evidence suggesting an association with worsening MG and adding some guidance when possible on alternatives to select from.

At the end of the day, the easiest way to assess medication safety in MG is to check and see if it is first anti cholinergic. While not all riskier drugs will be under the umbrella of anticholinergic, many will and it can offer you a quick guide when making rapid assessments. Patient history and their individual presentation will also make a large impact in the choices you make on their behalf. Always choose the least risky choice whenever available and in the hospital setting, monitor your patients carefully for any adverse changes that may be occurring. Please note that not all changes will present with clear markers. Be watchful for quiet crashing in MG when new medications are being onboarded.

Alpha-Interferon
Analgesics: (Can potentially worsen respiratory drive in myasthenics. Use with caution)
Antibiotics: (Aminoglycosides, Amoxicillin, Clarithromycin, Chloroquine, Cipro Erthromycin, Hydroxychloroquine, Penicillin, Clindamycin, Polymyxin, Gentamicin, neomycin, streptomycin, tobramycin, kanamycin, Netilmicin, Ketek, Tetracycline, Augmenti, Blaxin, Zithromax, Quinilones, Cephalosporins are considered the safest class to try)
Anti Convulsants: (Dilantin, Gabapentin, Phenytoin and Barbiturates)
Antihistamines and Decongestants: (Benadryl, Sudafed, Claritin D. -inhibits achetycholine post synaptically)
Antihelmintics
Antimuscarinic Drugs: (Medicines for Parkinsons; procyclidine, orphenadrine, trihexiphenidyl) Antimuscarinic Drugs: (for urinary incontinence; oxybutynin, trospium, tolterodine)
Atropine (Anti-cholinergic; sometimes used to reverse a cholinergic crisis. Robinul is a safer cholinergic reversal by comparison only but may not be available in emergencies.)
Botox
Cardiovascular Drugs: (Beta Blockers, Bretylium, Calcium Channel Blockers, Propafenone, Quinidine, Quinine)
Corticosteroids (moderate to high doses have been shown to temporarily worsen MG. It is important that steroids are started low and worked up slowly to help avoid this scenario.)
CT Dye/Contrast/Iodinated Radiographic Contrast: (Iothalamic acid, diatrizoate meglumine, diatrizoate methylsulfate)
D-L-carnitine
General Anesthetics***: (atracurium, cisatracurium, doxacurium, gallamine, mivacurium, pancuronium, pipecuronium, rocuronium, tubocurarine, and vecuronium. Inhibits/Interferes with neuromuscular transimission. To be used in extreme caution)
Hyoscine (used to treat bladder spasms)
Hormones: (Estrogen, Progesterone, Birth Control Pill)
H-2 Receptor Antagonists

Local Anesthetics (Lidocaine, Procaine, etc... Carbocaine is considered the safest in this family as it is shorter acting.)
Magnesium and Magnesium Products (natural or synthentic unless deficient in biochemistry.) Muscle Relaxants

Neuromuscular Blocking Agents
Opthalmalic Drugs: (Acetazolamide, Proparacaine/tropicamide, Beta Blocker eye drops, Timolol, betaxolol hydrochloride, Echothiophate. ALL dilators are anticholinergic!)
Pyschotropic Drugs: (Lithium, Phenothiazine, Tricyclic Antidepressants like Elavil) Rheumatologic Drugs: (Cholorquine, D-Penicillamine)
Statins

ANY OTHER MEDICINE that has anticholinergic properties OR interferes with transmission at the junction/synapse. IF IN DOUBT: Always double check!

** Agents such as Sevoflurane, Isoflurane, Desflurane, Halothane, Enflurane, and Nitrous oxide are used for intubation as well as maintenance of anesthesia. Myasthenic patients require smaller amounts of these agents than normal, but the effects on neuromuscular transmission do not extend beyond the discontinuation of the agent, thus permitting rapid post-operative extubation of patients with myasthenia gravis.

***Drugs such as Propafol and Opioids in therapeutic concentrations are considered to be safe for patients with defects of neuromuscular transmission.

Critical Treatment Considerations

Contraindicated Drugs

Emergent Respiratory Assessment

Myasthenia Gravis requires fastidious attention to the administration of medication to avoid a drug induced exacerbation or crisis. Learn how to make appropriate choices and find the lowest risk intervention for your patient.

Emergent Respiratory Assessment

Quick and appropriate respiratory assessment can mean the difference between stability and a crash. Explore the crucial parameters for EMS and beside presentation.

ER Triage Protocol

Emergent Respiratory Assessment

Surgery Considerations

Learn more about appropriate ER assessment for Myasthenia patients and how to set the patient up for success the moment they enter the hospital.

Surgery Considerations

Myasthenia Exacerbation Risks

Surgery Considerations

Learn how to set your patient up for success pre, peri and post operatively. Here you will learn how to assess beyond hospital protocols and adapt methods for critical success.

Emergent Bedside Assessment

Myasthenia Exacerbation Risks

Discover key details to help you make quick and accurate determinations at bedside to help you discern what needs a critical response and what is an appropriate response for Myasthenia patients.

Myasthenia Exacerbation Risks

Uncover common causes that can lead to rapid decline in Myasthenia and how to avoid unnecessary risks to your patient.