Myasthenia gravis crisisMANAGEMENT

ENDOCRINE AND METABOLIC PRESENTATIONS · 12 SECTIONS

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473 items

☷ Legend

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Cardiovascular Presentations66▾

Respiratory Presentations47▾

Neurological Presentations77▾

Gastrointestinal Presentations63▾

Genitourinary and Reproductive Presentations44▾

Infectious Disease Presentations146▾

Trauma Presentations88▾

Toxicologic Presentations67▾

Psychiatric Presentations25▾

Musculoskeletal and Rheumatologic Presentations89▾

Dermatology Presentations21▾

Environmental and Exposure Presentations26▾

Hematologic and Oncologic Presentations30▾

Pediatric-Specific Presentations13▾

Endocrine and Metabolic Presentations42▾

Acute Porphyria Adrenal crisis Adrenal Insufficiency (Addisonian Crisis)Dehydration Diabetes Insipidus Diabetic Ketoacidosis (DKA)Galactosemia Homocystinuria Hypercalcemia Hyperkalemia Hypermagnesemia Hypernatremia Hyperosmolar Hyperglycemic State (HHS)Hypertensive emergency Hypertensive urgency Hypocalcemia Hypoglycemia Hypogonadism (Acute Presentation)Hypokalemia Hypomagnesemia Hyponatremia Hypoparathyroidism (Tetany)Maple Syrup Urine Disease (Crisis)Medium-Chain Acyl-CoA Dehydrogenase Deficiency (MCAD)Metabolic Acidosis Metabolic Alkalosis Myasthenia gravis crisis Myxedema coma Pellagra Pheochromocytoma (Crisis)Pituitary Apoplexy Pompe Disease (GSD II)Respiratory Acidosis Respiratory Alkalosis Scurvy SIADH Starvation Ketosis Tarui Disease (GSD VII)Thyroid storm Tyrosinemia Vitamin D Deficiency (Severe-Rickets)Von Gierke Disease (GSD I)

ENT and Maxillofacial Presentations21▾

Ophthalmologic Presentations15▾

Obstetric Presentations17▾

Systemic and Miscellaneous Presentations15▾

01Approach to the Critical Patient/attcp53

Immediate priorities

›Airway and breathing

›Respiratory muscle weakness with rising PaCO2

›Early intubation triggers

›Forced vital capacity less than 20 mL/kg

›Maximal inspiratory pressure less negative than -30 cmH2O

›Negative inspiratory force less negative than -20 cmH2O

›Maximal expiratory pressure less than 40 cmH2O

›PaCO2 greater than 45 mmHg

›Bulbar weakness with secretion burden

›Oxygenation pitfalls

›Normal SpO2 despite impending ventilatory failure

›Hypercapnia preceding hypoxemia on arterial blood gas

›Circulation

›Shock etiologies

›Sepsis with triggering infection

›Arrhythmia from comorbidity or medication effect

›Hemodynamic monitoring

›Continuous telemetry

›Frequent blood pressure trend

›Neuromuscular rescue pathway

›Trigger identification and reversal

›Infection evaluation and early treatment

›Medication review for MG worsening agents

›Rapid immunomodulation selection

›Plasma exchange when available and not contraindicated

›IV immunoglobulin when plasma exchange not feasible

›Team activation and location

›ICU admission default for true crisis

›Continuous ventilatory monitoring capability

›Rapid intubation readiness

›Early neurology consult

›Confirm MG flare versus mimics

›Align rescue therapy choice and timing

Airway strategy

›Intubation and ventilation

›Intubation planning considerations

›Bulbar dysfunction and aspiration risk

›Anticipated difficult secretion management

›Neuromuscular blocking agents precautions

›Increased sensitivity to nondepolarizing agents

›Relative resistance to succinylcholine

›Post intubation goals

›Lung protective ventilation if no primary lung disease

›Aggressive secretion clearance plan

Key concepts

›Definition and scope

›Myasthenic crisis

›Respiratory failure requiring ventilatory support

›Impending crisis with rapidly worsening respiratory or bulbar weakness

›Common precipitants

›Respiratory infection

›Aspiration pneumonia

›Medication induced worsening

›Postoperative stress

›Pregnancy and postpartum immune shifts

02History/hx62

Focused history

›Symptom pattern and timeline

›Fluctuating weakness

›Worse with exertion

›Worse later in day

›Bulbar symptoms

›Dysphagia

›Dysarthria

›Drooling

›Ocular symptoms

›Ptosis

›Diplopia

›Respiratory symptoms

›Orthopnea

›Dyspnea on exertion

›Weak cough

›Prior MG details

›MG subtype

›Acetylcholine receptor antibody positive

›MuSK antibody positive

›Seronegative MG

›Baseline functional status

›Prior need for NIV or intubation

›Prior plasma exchange response

›Prior IVIG response

›Current medications

›Pyridostigmine dose and timing

›Corticosteroid dose and recent changes

›Immunosuppressant regimen

›Trigger screen

›Infectious symptoms

›Fever

›Cough

›Dysuria

›Recent medication exposures

›Aminoglycosides

›Fluoroquinolones

›Macrolides

›Magnesium containing products

›Beta blockers

›Neuromuscular blockers

›Recent surgery or anesthesia exposure

›Recent intubation

›Postoperative pain control agents

›Mimic screen

›Excess cholinergic symptoms

›Diarrhea

›Sweating

›Salivation

›Other neurologic symptoms

›Focal deficits suggesting stroke

›Altered mental status suggesting encephalopathy or sedative effect

Medication and allergy history

›High risk medications list

›Antibiotics associated with worsening MG

›Aminoglycosides

›Fluoroquinolones

›Macrolides

›Cardiovascular agents associated with worsening MG

›Beta blockers

›Calcium channel blockers

›Sedatives and analgesics

›Opioid induced hypoventilation risk

›Benzodiazepine induced hypoventilation risk

03Physical Exam/exam34

Respiratory and bulbar assessment

›Work of breathing

›Accessory muscle use

›Paradoxical breathing

›Tachypnea without distress mismatch

›Speech and counting tests

›Single breath count decline

›Inability to speak full sentences

›Bulbar function

›Voice quality

›Nasal speech

›Wet voice

›Swallow safety

›Pooling secretions

›Weak gag or cough

›Bedside neuromuscular weakness pattern

›Neck flexion weakness

›Head lift weakness

›Proximal limb weakness

›Shoulder abduction fatigue

›Hip flexion fatigue

Neurologic and general exam

›Ocular findings

›Ptosis variability

›Fatigability with sustained upgaze

›Extraocular movement limitation

›Diplopia provocation with sustained gaze

›Autonomic and cholinergic findings

›Miosis

›Bradycardia

›Diaphoresis

›Bronchorrhea

›Infection focus

›Lung exam for pneumonia

›Skin for cellulitis

›Urinary symptoms correlation

04Differential Diagnosis/ddx26

Life threatening and common mimics

›Neuromuscular causes of ventilatory failure

›Myasthenic crisis ICD-10 G70.01 SNOMED CT myasthenic crisis

›Respiratory or bulbar weakness with hypercapnia risk

›Cholinergic crisis ICD-10 T44.0 SNOMED CT cholinergic crisis

›Muscarinic signs with weakness

›Guillain Barre syndrome ICD-10 G61.0 SNOMED CT Guillain Barre syndrome

›Areflexia and ascending weakness

›Botulism ICD-10 A05.1 SNOMED CT botulism

›Descending paralysis with autonomic features

›Central nervous system causes

›Brainstem stroke ICD-10 I63.9 SNOMED CT cerebral infarction

›Focal cranial nerve deficits

›Intracranial hemorrhage ICD-10 I61.9 SNOMED CT intracerebral hemorrhage

›Headache and decreased consciousness

›Pulmonary and systemic causes

›Pneumonia with sepsis ICD-10 J18.9 A41.9 SNOMED CT pneumonia sepsis

›Fever and infiltrate

›Pulmonary embolism ICD-10 I26.99 SNOMED CT pulmonary embolism

›Pleuritic pain and hypoxemia

›COPD or asthma exacerbation ICD-10 J44.1 J45.901 SNOMED CT obstructive airway exacerbation

›Wheeze and hyperinflation

›Medication and toxicologic causes

›Sedative overdose ICD-10 T42.4 T40.2 SNOMED CT poisoning

›Depressed mental status

›Magnesium toxicity ICD-10 T47.8 SNOMED CT hypermagnesemia

›Hyporeflexia and hypotension

05Laboratory Tests/lt34

Core labs

›Baseline safety and trigger evaluation

›Complete blood count for infection and anemia

›Leukocytosis supporting infection trigger

›Hemoglobin trend for alternative dyspnea contributors

›Electrolytes and renal function

›Potassium for arrhythmia risk

›Creatinine for plasma exchange and IVIG planning

›Glucose mmol/l for stress hyperglycemia or hypoglycemia

›Hypoglycemia alternative for weakness and altered mentation

›Liver enzymes for medication metabolism planning

›Hepatic dysfunction affecting sedative choices

›Infection workup

›Blood cultures when febrile or septic physiology

›Collection before antibiotics when feasible

›Urinalysis and culture for urinary source

›Pyuria or bacteriuria correlation with symptoms

Blood gas and respiratory labs

›Ventilation and acid base status

›Arterial blood gas for hypercapnia assessment

›PaCO2 trending as primary decompensation marker

›PaO2 evaluation when hypoxemia present

›Venous blood gas as screening option

›Rising pCO2 trend supporting ventilatory failure

›Bedside respiratory metrics

›Serial forced vital capacity trend

›Rapid decline over hours predicting need for intubation

›Maximal inspiratory pressure trend

›Weakening inspiratory force predicting impending failure

Myasthenia specific testing

›Antibody and associated disease testing

›AChR antibody status if unknown

›Not time critical for acute airway decisions

›MuSK antibody status if AChR negative and phenotype suggests

›Higher bulbar and respiratory involvement risk

›Thyroid studies when clinical suspicion for autoimmune association

›Thyroid dysfunction as weakness contributor

06Diagnostic Tests/dt42

Scoring Systems

›Severity stratification

›MGFA clinical classification

›Class I ocular only

›Class II mild generalized

›Class III moderate generalized

›Class IV severe generalized

›Class V intubation with or without ventilation

›Quantitative Myasthenia Gravis score

›Bedside tracking of response to rescue therapy

›MG Activities of Daily Living score

›Bulbar and respiratory symptom tracking

›Respiratory risk tools

›Bedside spirometry thresholds

›Forced vital capacity less than 20 mL/kg

›Negative inspiratory force less negative than -20 cmH2O

›Maximal expiratory pressure less than 40 cmH2O

MRI

›Neuroimaging for mimics

›Brain MRI with diffusion weighted imaging

›Brainstem infarct evaluation when focal deficits

›Demyelinating disease evaluation when atypical course

›Thoracic MRI when CT contraindicated for mediastinal evaluation

›Thymoma assessment when contrast allergy and stable patient

›Chest imaging

›Chest radiograph

›Aspiration pneumonia screening

›Atelectasis and mucus plugging clues

›CT chest with contrast when stable

›Thymoma evaluation

›Alternative pulmonary diagnosis evaluation

›Neuroimaging for alternate diagnosis

›CT head without contrast when sudden focal deficits or altered mental status

›Hemorrhage exclusion prior to anticoagulation consideration

Ultrasound (or US)

›Point of care ultrasound adjuncts

›Lung ultrasound

›Consolidation suggesting pneumonia trigger

›Pleural effusion affecting ventilation

›Diaphragm ultrasound

›Reduced excursion supporting diaphragmatic weakness

›Trend monitoring during recovery

›Cardiac ultrasound when shock or unexplained dyspnea

›LV dysfunction alternative cause

›Pericardial effusion assessment

07Disposition/dispo25

Level of care

›ICU criteria

›Any ventilatory support requirement

›Invasive mechanical ventilation

›Noninvasive ventilation with close monitoring

›Rapidly progressive bulbar symptoms

›Inability to manage secretions

›Aspiration events

›Respiratory mechanics decline

›Forced vital capacity less than 20 mL/kg

›PaCO2 greater than 45 mmHg

›Stepdown criteria

›Stable respiratory mechanics for 24 hours

›Improving forced vital capacity trend

›No NIV requirement

›Bulbar symptoms controlled

›Safe swallow plan in place

Transfer and consults

›Neurology involvement

›Rescue therapy selection

›Plasma exchange versus IVIG decision

›Long term immunotherapy planning

›Steroid strategy

›Steroid sparing agent timing

›Critical care involvement

›Ventilator management and weaning strategy

›Tracheostomy consideration for prolonged ventilation

08Treatment/t89

Respiratory support

›Oxygenation and ventilation support

›Noninvasive ventilation pathway

›BiPAP trial criteria

›Alert and cooperative patient

›Minimal secretion burden

›No severe bulbar dysfunction

›BiPAP failure predictors

›PaCO2 greater than 45 mmHg

›Inability to clear secretions

›Invasive ventilation pathway

›Intubation triggers

›Forced vital capacity less than 20 mL/kg

›Rapid respiratory mechanics decline

›Bulbar failure with aspiration risk

›Airway secretion strategy

›Chest physiotherapy

›Suctioning plan

›Humidification

›Nutrition and aspiration prevention

›NPO status during unsafe swallow

›Speech language pathology evaluation when feasible

›Enteral feeding route planning

›Nasogastric or post pyloric tube based on aspiration risk

Rapid immunomodulation

›Plasma exchange

›Standard course

›5 exchanges over 7 to 14 days

›1.0 to 1.5 plasma volumes per exchange

›Albumin replacement typical

›Contraindications and risks

›Hemodynamic instability risk

›Central line complications

›Coagulopathy monitoring

›Intravenous immunoglobulin

›Standard dosing

›0.4 g/kg/day for 5 days

›Ideal or adjusted body weight per local protocol

›Contraindications and risks

›Thrombosis risk assessment

›Renal dysfunction risk monitoring

›Aseptic meningitis risk counseling

Symptomatic therapy and steroid strategy

›Acetylcholinesterase inhibitors

›Pyridostigmine oral

›Typical outpatient dosing range 30 to 60 mg every 4 to 6 hours

›Dose adjustment for side effects

›Intubated patient approach

›Temporary hold strategy

›Reduced secretion burden goal

›Cholinergic crisis avoidance

›Corticosteroids

›Continuation strategy

›Continue home dose when already on chronic therapy

›Stress dose consideration when septic shock physiology

›Initiation strategy

›Early neurology guided initiation

›Risk of transient worsening with high dose initiation

›Long term immunosuppressants

›Continuation considerations

›Azathioprine continuation when stable and no contraindication

›Mycophenolate continuation when stable and no contraindication

›Infection and cytopenia precautions

›Hold strategy in severe sepsis based on multidisciplinary decision

Trigger treatment and avoidance

›Infection management

›Early antibiotics when infection suspected

›Avoid high risk MG worsening antibiotics when alternatives exist

›Aspiration pneumonia pathway

›Airway clearance measures

›Appropriate anaerobic and oral flora coverage per local guidance

›Medication avoidance list in crisis

›Neuromuscular transmission impairing agents

›Magnesium salts

›Aminoglycosides

›Fluoroquinolones

›Macrolides

›Beta blockers

›Sedation minimization strategy

›Avoid oversedation masking hypercapnia

Cholinergic crisis management

›Recognition and differentiation

›Muscarinic features

›Diarrhea

›Sweating

›Salivation

›Bradycardia

›Overmedication history

›Recent pyridostigmine dose escalation

›Management approach

›Anticholinesterase hold

›Symptom improvement monitoring

›Atropine for severe muscarinic symptoms

›Titrated dosing based on bradycardia and bronchorrhea

09Special Populations/sp36

Pregnancy

›Maternal considerations

›Increased aspiration risk with bulbar weakness

›Early obstetric and anesthesia involvement

›Rescue therapy compatibility

›Plasma exchange use when indicated

›IVIG use when indicated

›Medication considerations

›Pyridostigmine compatibility in pregnancy

›Dose based on symptom control and side effects

›Corticosteroid considerations

›Gestational diabetes monitoring

›Hypertension monitoring

›Neonatal considerations

›Transient neonatal myasthenia risk

›Neonatal observation plan after delivery

Geriatric

›Presentation differences

›Reduced reserve and rapid fatigue

›Earlier ventilatory failure despite subtle signs

›Delirium and hypercapnia interaction

›Altered mental status from CO2 retention

›Therapy risks

›IVIG thrombosis risk higher

›VTE risk mitigation plan

›Plasma exchange access complications higher

›Line complication monitoring

Pediatrics

›Juvenile MG considerations

›Weight based thresholds for respiratory mechanics

›Forced vital capacity mL/kg trend tracking

›Rescue therapy dosing

›IVIG 0.4 g/kg/day for 5 days

›Plasma exchange with pediatric apheresis expertise

›Safety considerations

›Sedation sensitivity

›Hypercapnia risk with minimal sedation

›Family education

›Trigger medication avoidance list reinforcement

10Background/b34

Epidemiology

›Frequency and burden

›Myasthenic crisis occurrence in generalized MG

›Highest risk early in disease course

›Common triggers

›Infection as leading precipitant

›Medication exposure as preventable trigger

Pathophysiology

›Neuromuscular junction failure

›Autoantibody mediated impaired transmission

›AChR antibodies reducing receptor availability

›MuSK antibodies disrupting receptor clustering

›Fatigable weakness mechanism

›Decrement with repetitive activation

›Respiratory failure mechanisms

›Diaphragm and intercostal weakness

›Hypoventilation and CO2 retention

›Upper airway muscle weakness

›Airway collapse and secretion retention

›Bulbar weakness

›Aspiration and pneumonia cycle

Therapeutic Considerations

›Rescue therapy rationale

›Plasma exchange mechanism

›Rapid removal of pathogenic antibodies

›IVIG mechanism

›Immune modulation and antibody neutralization

›Clinical effect timing

›Plasma exchange often faster onset than IVIG

›Both used as short term bridging therapies

›Steroid initiation risk

›Early transient worsening possible

›ICU capable monitoring preferred when starting high dose

›Extubation and weaning principles

›Improvement in respiratory mechanics guiding weaning

›Forced vital capacity trend upward

›Adequate cough and secretion handling

11Patient Discharge Instructions/pdi20

copy discharge instructions

›Myasthenia flare education

›Symptoms needing urgent reassessment

›New or worsening shortness of breath

›Trouble swallowing or choking on liquids

›Weak cough or inability to clear secretions

›Rapidly worsening weakness or inability to hold head up

›Blue lips or confusion

›Medication safety

›Do not stop MG medicines without clinician guidance

›Avoid new medicines without checking MG safety list

›Infection precautions

›Early assessment for fever or cough

›Hydration and rest during viral illness

›Follow up plan

›Neurology follow up timing

›Within 1 week after ED visit for exacerbation

›Return to ED criteria

›Any breathing difficulty

›Any swallowing difficulty

›Any rapid symptom progression

12References/r18

Clinical guidelines and consensus

›International Consensus Guidance for Management of Myasthenia Gravis 2016 Neurology

›IVIG and plasma exchange for impending and manifest myasthenic crisis

›Expert consensus guidance for global MG management

›International Consensus Guidance for Management of Myasthenia Gravis 2020 update published 2021

›Updated recommendations across MG subtypes and therapies

›Expert consensus for crisis level care and rescue therapies

Evidence based sources

›JAMA Neurology 2008 noninvasive ventilation in myasthenic crisis

›Hypercapnia association with BiPAP failure

›Patient selection importance for NIV success

›Practical approach review 2020 in open access neurology literature

›Symptomatic and immunotherapy sequencing overview

›Steroid related transient worsening considerations

›Muscle and Nerve 2023 myasthenic crisis review

›Neuromuscular blocker sensitivity considerations

›ICU management and complications overview

›Peer reviewed open access review 2024 pitfalls in respiratory failure evaluation in myasthenic crisis

›Limited distress signs despite CO2 retention

›Need for ABG and clinical correlation

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Reviewed by SymptomDx Medical Team · Last reviewed June 16, 2026

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