neuromuscular emergencies
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Neuromuscular Emergencies. Hanni Bouma R3 Neurology. Outline. Approach to neuromuscular respiratory failure Signs & Symptoms Investigations Knowing when (to ask someone else) to intubate Overview of: Myasthenic crisis GBS Botulism. True or false? Regarding GBS… - PowerPoint PPT PresentationTRANSCRIPT
Neuromuscular Neuromuscular EmergenciesEmergencies
Hanni BoumaHanni Bouma
R3 NeurologyR3 Neurology
OutlineOutline Approach to neuromuscular Approach to neuromuscular
respiratory failurerespiratory failure Signs & SymptomsSigns & Symptoms InvestigationsInvestigations Knowing when (to ask someone else) to Knowing when (to ask someone else) to
intubateintubate Overview of:Overview of:
Myasthenic crisisMyasthenic crisis GBSGBS BotulismBotulism
True or false? Regarding GBS…True or false? Regarding GBS…
~10% of pts will require intubation.~10% of pts will require intubation. All cases of suspected GBS should be All cases of suspected GBS should be
treated with either IVIG or PLEX.treated with either IVIG or PLEX. Normal CSF protein precludes the diagnosis.Normal CSF protein precludes the diagnosis. Hypertension is the most common Hypertension is the most common
autonomic complication.autonomic complication.
Case 1Case 1 A 32-yo M with MG since age 20, on stable A 32-yo M with MG since age 20, on stable
dose of pred 40, Imuran, and Mestinon, is dose of pred 40, Imuran, and Mestinon, is admitted to hospital for elective bowel admitted to hospital for elective bowel surgery (complications of diverticulitis)surgery (complications of diverticulitis)
Pt. has persistent diplopia and mild Pt. has persistent diplopia and mild fatigable weakness at the deltoidsfatigable weakness at the deltoids
The surgery team calls you the morning of The surgery team calls you the morning of his scheduled surgery to ask if they should his scheduled surgery to ask if they should do anything for his myasthenia. do anything for his myasthenia.
Case 1Case 1 You should:You should: A) Suggest switching to equivalent dosage A) Suggest switching to equivalent dosage
of IV steroids while NPOof IV steroids while NPO B) Review med list & advise re: drugs that B) Review med list & advise re: drugs that
might trigger a crisis (ie. Antibiotics!!)might trigger a crisis (ie. Antibiotics!!) C) Kindly recommend postponing the C) Kindly recommend postponing the
surgery for pre-op IVIG or PLEX surgery for pre-op IVIG or PLEX D) All of the aboveD) All of the above
Case 2Case 2
A 10-month-old infant presents with A 10-month-old infant presents with constipation and poor feeding constipation and poor feeding followed by progressive hypotonia, followed by progressive hypotonia, descending weakness, dilated pupils, descending weakness, dilated pupils, and bilateral ptosis. and bilateral ptosis.
What is the likely diagnosis?What is the likely diagnosis? How was it likely acquired?How was it likely acquired? How would you treat him?How would you treat him?
Case 3Case 3
You are called to see a patient in ICU You are called to see a patient in ICU with known diagnosis of MG, recurrent with known diagnosis of MG, recurrent crises leading to ICU admissions, on crises leading to ICU admissions, on stable dose of pred 60 mg qd and stable dose of pred 60 mg qd and Imuran. Admitted with MG crisis, Imuran. Admitted with MG crisis, intubated then trach’ed. Now, 2 weeks intubated then trach’ed. Now, 2 weeks later, “doing better” as per ICU. They later, “doing better” as per ICU. They want to start tapering his prednisone. want to start tapering his prednisone. What do you advise them to do?What do you advise them to do?
Case 3Case 3
1) Agree with their plan to begin a 1) Agree with their plan to begin a slow tapering course by 10 mg qweek slow tapering course by 10 mg qweek initially.initially.
2) Discuss the patient with their 2) Discuss the patient with their treating neurologist.treating neurologist.
3) Advise them to avoid rapid tapering 3) Advise them to avoid rapid tapering of steroids given the risk of recurrent of steroids given the risk of recurrent crisis.crisis.
4) Both 2 & 3.4) Both 2 & 3.
Part 1: Part 1: Neuromuscular Respiratory Neuromuscular Respiratory
FailureFailure
Respiratory Failure BasicsRespiratory Failure Basics
Type I:Type I: Hypoxia without hypercapniaHypoxia without hypercapnia Usually associated with ↑ WOBUsually associated with ↑ WOB V/Q mismatch most commonV/Q mismatch most common
Vascular disease/shunts (PE, Vascular disease/shunts (PE, Pulm. HTN, R->L shunts)Pulm. HTN, R->L shunts)
Interstitial lung disease (ARDS, Interstitial lung disease (ARDS, cardiogenic pulmonary edema, cardiogenic pulmonary edema, pneumonia)pneumonia)
Pneumothorax, atelectasisPneumothorax, atelectasis
Type II:Type II: Hypercapnia with or w/o hypoxia Hypercapnia with or w/o hypoxia A.k.a. hypoventilationA.k.a. hypoventilation
Neuromuscular conditionsNeuromuscular conditions Deformities (kyphoscoliosis)Deformities (kyphoscoliosis) Reduced breathing effort (extreme Reduced breathing effort (extreme
obesity, drug effects, brainstem lesion obesity, drug effects, brainstem lesion affecting respiratory drive)affecting respiratory drive)
Increased airway resistance (asthma, Increased airway resistance (asthma, COPD)COPD)
Neuromuscular CausesNeuromuscular Causes Spinal cord lesionSpinal cord lesion
Cervical cord compression, transverse myelitisCervical cord compression, transverse myelitis Motor neuron lesionMotor neuron lesion
ALSALS Peripheral nerve lesionPeripheral nerve lesion
GBSGBS, CIDP, critical illness polyneuropathy, Lyme , CIDP, critical illness polyneuropathy, Lyme disease, tick paralysis, toxicdisease, tick paralysis, toxic
NMJ disorderNMJ disorder MG, MG, LEMS, LEMS, botulismbotulism, organophosphate poisoning, organophosphate poisoning
Muscle lesionMuscle lesion Polymyositis, dermatomyositis, critical illness Polymyositis, dermatomyositis, critical illness
myopathy, hyperthyroidism, congenital myopathy myopathy, hyperthyroidism, congenital myopathy (muscular dystrophy), mitochrondrial myopathy(muscular dystrophy), mitochrondrial myopathy
HistoryHistory Time course?Time course?
progressive weakness over hours to days progressive weakness over hours to days GBS GBS fluctuating weakness (on an hourly basis) present fluctuating weakness (on an hourly basis) present
for weeks/months for weeks/months MG MG Distribution of weakness?Distribution of weakness?
Proximal > distal (MG & GBS)Proximal > distal (MG & GBS) Ascending in GBSAscending in GBS
Sensory Sx.?Sensory Sx.? Distal paresthesias common in GBSDistal paresthesias common in GBS No sensory inv’t in MGNo sensory inv’t in MG
HistoryHistory +FH?+FH? Pain?Pain?
Low backache frequently in GBS; neck pain: C-Low backache frequently in GBS; neck pain: C-spine lesion?spine lesion?
Antecedent illness?Antecedent illness? 60% of GBS triggered by viral URT illness or 60% of GBS triggered by viral URT illness or
C.jejuniC.jejuni gastro gastro 40% of myasthenic crises triggered by 40% of myasthenic crises triggered by
infectioninfection MedicationsMedications Exposure to fertilizers & pesticides?Exposure to fertilizers & pesticides?
Organophosphate poisoningOrganophosphate poisoning Recent dietRecent diet
Botulism from home-canned goodsBotulism from home-canned goods
ExamExam Long, thin face? (myotonic dystrophy? Long, thin face? (myotonic dystrophy?
Congenital?)Congenital?) Skin rash (dermatomyositis?Skin rash (dermatomyositis? CNsCNs
Pupils: Pupils: Reactivity may be lost in botulism or Miller-Reactivity may be lost in botulism or Miller-
Fisher variant of GBSFisher variant of GBS EOM: EOM:
Opthalmoparesis or ptosis (MG? Opthalmoparesis or ptosis (MG? mitochondrial D/O? MFS?)mitochondrial D/O? MFS?)
Presence or absence of bulbar weakness?Presence or absence of bulbar weakness? Motor exam: Motor exam:
Fasciculations? (ALS, organophosphate Fasciculations? (ALS, organophosphate poisoning); tone; power (fatigable weakness? poisoning); tone; power (fatigable weakness? Distribution proximal vs. distal?)Distribution proximal vs. distal?)
ExamExam Sensory: Sensory:
Normal in MGNormal in MG Distal sensory loss in GBS, esp vib/propDistal sensory loss in GBS, esp vib/prop Sensory level at C-spine level w/ quadriparesis Sensory level at C-spine level w/ quadriparesis
= C-spine lesion= C-spine lesion Coordination:Coordination:
Ataxia in MF variant of GBSAtaxia in MF variant of GBS Reflexes:Reflexes:
AreflexiaAreflexia in GBS; preserved in MG in GBS; preserved in MG
MechanismsMechanisms1)1) Bulbar dysfunction: Bulbar dysfunction:
Facial, oropharyngeal, laryngeal weakness Facial, oropharyngeal, laryngeal weakness upper airway obstruction in supine upper airway obstruction in supine position position
Impaired swallowing Impaired swallowing aspiration aspiration2) 2) Inspiratory muscle Inspiratory muscle
weakness/diaphragmatic paralysisweakness/diaphragmatic paralysis atelectasis atelectasis V/Q mismatch V/Q mismatch hypoxia hypoxia
3) 3) Expiratory muscle weaknessExpiratory muscle weakness hypoventilation hypoventilation AND AND weak cough/poor weak cough/poor secretion clearance secretion clearance aspiration, pneumonia aspiration, pneumonia
4) 4) Acute complicationsAcute complications PE PE
SymptomsSymptoms If subacute (ie. GBS): dyspnoea and orthopnoeaIf subacute (ie. GBS): dyspnoea and orthopnoea
Easy to overlookEasy to overlook If gradual onset, inadequate respiration usually If gradual onset, inadequate respiration usually
occurs first during sleepoccurs first during sleep Symptoms of nocturnal hypoventilation: Symptoms of nocturnal hypoventilation:
a broken sleep pattern, nightmares, nocturnal a broken sleep pattern, nightmares, nocturnal confusion, morning headache, daytime fatigue, confusion, morning headache, daytime fatigue, mental clouding and somnolence. mental clouding and somnolence.
SOBOE less common in NMDs than in those SOBOE less common in NMDs than in those with other Cardioresp D/O (reduced mobility)with other Cardioresp D/O (reduced mobility)
Dyspnoea when lying flat or immersed in water Dyspnoea when lying flat or immersed in water suggests weakness of the diaphragmsuggests weakness of the diaphragm
Warning signsWarning signs Rapid, shallow breathingRapid, shallow breathing StridorStridor Bulbar weaknessBulbar weakness
weak cough, nasal voice, pooling of saliva weak cough, nasal voice, pooling of saliva Orthopnea Orthopnea Staccato speechStaccato speech Abdominal paradoxAbdominal paradox
http://http://www.youtube.com/watch?vwww.youtube.com/watch?v==RFGzdNFuXIMRFGzdNFuXIM
Weakness of neck & trapezius musclesWeakness of neck & trapezius muscles Single-breath countSingle-breath count
Mehta, S. “Neuromuscular disease causing acute respiratory failure.” Respiratory Care, 2006. 51 (9): 1016-1023.
InvestigationsInvestigations Bedside PFTs:Bedside PFTs: “20/30/40 rule”“20/30/40 rule”
Vital capacity (max exhaled volume after full Vital capacity (max exhaled volume after full inspiration). Normal = 60 ml/kg (4 L in 70 kg inspiration). Normal = 60 ml/kg (4 L in 70 kg person). person). VC < 20 ml/kg (or 1 L) means VC < 20 ml/kg (or 1 L) means intubationintubation
Max inspiratory pressure. Index of ability to avoid Max inspiratory pressure. Index of ability to avoid atelectasis. Normal = >atelectasis. Normal = > 80 cm H2O (male), >70 80 cm H2O (male), >70 cm H2O (female)cm H2O (female). . MIP >-30 means intubationMIP >-30 means intubation
Max expiratory pressure. Index of ability to Max expiratory pressure. Index of ability to cough/clear secretions. Mean MEP = 140 cm H2O cough/clear secretions. Mean MEP = 140 cm H2O (male), 95 cm H20 (female). (male), 95 cm H20 (female). MEP <40 means MEP <40 means intubationintubation
InvestigationsInvestigations ABG: ABG:
Hypercarbia (PCOHypercarbia (PCO2 2 > 45 mmHg)> 45 mmHg)
• PCOPCO2 2 often normal or low until late in often normal or low until late in NM resp failureNM resp failure
• Established resp failure from NMDs: low pO2, Established resp failure from NMDs: low pO2, normal pH, elevated bicarb & pCO2 normal pH, elevated bicarb & pCO2
• Elevations of bicarb & pH with normal pO2 & Elevations of bicarb & pH with normal pO2 & pCO2 suggest pCO2 suggest nocturnal hypoventilationnocturnal hypoventilation
Hypoxia (POHypoxia (PO2 2 < 75 mmHg) = usually < 75 mmHg) = usually atelectasis or pneumonia in acute settingatelectasis or pneumonia in acute setting
Basic labs (CBC, SMA-10, LFTs, CK)Basic labs (CBC, SMA-10, LFTs, CK) CXRCXR
Predictors of need for MVPredictors of need for MV
20/30/40 rule20/30/40 rule
or reduction in VC, MIP, MEP by >30%or reduction in VC, MIP, MEP by >30%
POPO22 <70 mmHg on RA or PCO <70 mmHg on RA or PCO22 >50 >50 mmHg w/ acidosismmHg w/ acidosis
Dysarthria, dysphagia, impaired gag Dysarthria, dysphagia, impaired gag reflexreflex
Intubation: things to think Intubation: things to think aboutabout
Code status?Code status? Call ICU if signs of imminent resp Call ICU if signs of imminent resp
failurefailure
Identify Identify earlyearly to avoid emergency to avoid emergency intubation…elective intubation always intubation…elective intubation always preferredpreferred Minimizes atelectasis/pneumoniaMinimizes atelectasis/pneumonia Minimizes complications of intubation specific to Minimizes complications of intubation specific to
NMDsNMDs Avoid depolarizing NM blockersAvoid depolarizing NM blockers
NPPV?NPPV?
Few studies on its use in GBS & MGFew studies on its use in GBS & MG Inappropriate if upper airway Inappropriate if upper airway
function severely impairedfunction severely impaired More often used in chronic NMDs More often used in chronic NMDs
(ALS, muscular dystrophies) for (ALS, muscular dystrophies) for chronic hypoventilationchronic hypoventilation
General careGeneral care Serial PFTs (MIP/MEP/FVC) Serial PFTs (MIP/MEP/FVC) bid to qidbid to qid Electrolytes: low potassium, high Electrolytes: low potassium, high
magnesium & low phosphate magnesium & low phosphate exacerbate exacerbate muscle weaknessmuscle weakness
Chest physio, suctioning & incentive Chest physio, suctioning & incentive spirometryspirometry
DVT prophylaxisDVT prophylaxis HOB elevationHOB elevation NPO if bulbar weakness; NG or Dobhoff NPO if bulbar weakness; NG or Dobhoff
feedingfeeding
Part 2:Part 2:
MGMGGBSGBS
BotulismBotulism
MGMG
Ab-mediated attack on nicotinic Ach rec Ab-mediated attack on nicotinic Ach rec defective transmission across NMJ defective transmission across NMJ
Bimodal: F 20-30 yo; M 50-60 yoBimodal: F 20-30 yo; M 50-60 yo 2 autoimmune forms2 autoimmune forms
Ach receptor Ab+: 80% with generalized MG Ach receptor Ab+: 80% with generalized MG & 50% with ocular MG& 50% with ocular MG
Anti-MuSK Ab+: 50% of patients who are Anti-MuSK Ab+: 50% of patients who are Ach rec Ab negative; typically female with Ach rec Ab negative; typically female with prominent bulbar weaknessprominent bulbar weakness
PresentationPresentation Motor:Motor:
Fluctuating, fatigable weaknessFluctuating, fatigable weakness involving involving eyes (90%), face/neck/oropharynx (80%), limbs eyes (90%), face/neck/oropharynx (80%), limbs (60%)(60%)
Limbs rarely affected in isolationLimbs rarely affected in isolation Rest restores strength (at least partially)Rest restores strength (at least partially)
Sensory: normalSensory: normal Reflexes: preservedReflexes: preserved Thymic abnormalities:Thymic abnormalities:
Malignant thymoma in 10-15% (more severe Malignant thymoma in 10-15% (more severe disease)disease)
Thymic hyperplasia in 50-70%Thymic hyperplasia in 50-70%
InvestigationsInvestigations
Ach receptor AbsAch receptor Abs Anti-MuSK AbsAnti-MuSK Abs Edrophonium (Tensilon) test: obsoleteEdrophonium (Tensilon) test: obsolete EMG:EMG:
Repetitive nerve stimulationRepetitive nerve stimulation: >10% : >10% decrement in amplitude betw 1decrement in amplitude betw 1stst & 5 & 5thth CMAP CMAP
Single-fiber: Single-fiber: “jitter” “jitter” Sens >95% for MG but not specificSens >95% for MG but not specific
Management: generalManagement: general Symptomatic therapy Symptomatic therapy (mild-moderate weakness)(mild-moderate weakness)::
Cholinesterase inhibitors (Cholinesterase inhibitors (MestinonMestinon)) Short-term disease suppression:Short-term disease suppression:
To hasten clinical improvement in hospitalized pts w/ To hasten clinical improvement in hospitalized pts w/ crisis or impending crisis; pre-operatively; chronic crisis or impending crisis; pre-operatively; chronic refractory diseaserefractory disease
PLEX PLEX oror IVIG IVIG Long-term immunosuppression:Long-term immunosuppression:
When weakness is inadequately controlled by MestinonWhen weakness is inadequately controlled by Mestinon PrednisonePrednisone AzathioprineAzathioprine (if steroid failure or excessive SE) (if steroid failure or excessive SE) Cyclosporine, Mycophenolate mofetil…Cyclosporine, Mycophenolate mofetil…
Myasthenic CrisisMyasthenic Crisis
Defined by resp failure requiring Defined by resp failure requiring ventilatory assistanceventilatory assistance
Occurs in 20-30%; mortality 5%Occurs in 20-30%; mortality 5% Common precipitants:Common precipitants:
Infection in 40% (esp respiratory)Infection in 40% (esp respiratory) MedicationsMedications SurgerySurgery PregnancyPregnancy AspirationAspiration
Drugs that exacerbate MGDrugs that exacerbate MG
AntibioticsAntibiotics: (**Penicillins : (**Penicillins like Tazocin are OK!)like Tazocin are OK!) Aminoglycosides (genta, Aminoglycosides (genta,
tobra)tobra) Fluroquinolones (cipro)Fluroquinolones (cipro) Macrolides Macrolides
(erythromycin, azithro, (erythromycin, azithro, tetracycline, tetracycline, doxycycline)doxycycline)
Cardiac:Cardiac: All beta-blockersAll beta-blockers Calcium channel Calcium channel
blockersblockers Anticonvulsants:Anticonvulsants:
Phenytoin, CBZPhenytoin, CBZ
Antipsychotics, lithiumAntipsychotics, lithium Thyroid hormonesThyroid hormones Magnesium toxicityMagnesium toxicity Iodinated contrast Iodinated contrast
agentsagents Muscle relaxants Muscle relaxants
BaclofenBaclofen Long-acting benzosLong-acting benzos
**Too much **Too much anticholinesteraseanticholinesterase
Myasthenic crisis: Myasthenic crisis: managementmanagement
GeneralGeneral Determine if resp failure is imminent!!Determine if resp failure is imminent!! Stop any meds that may be contributingStop any meds that may be contributing
Mestinon usually stopped as wellMestinon usually stopped as well May contribute to increased airway secretions in May contribute to increased airway secretions in
intubated patientsintubated patients Treat any infectionTreat any infection
Myasthenic Crisis: Myasthenic Crisis: managementmanagement
SpecificSpecific PLEX or IVIG: PLEX or IVIG:
start one or the other, quicklystart one or the other, quickly Comparable efficacyComparable efficacy
Evidence somewhat limited…TBD laterEvidence somewhat limited…TBD later Earlier response seen with PLEX, but more Earlier response seen with PLEX, but more
adverse eventsadverse events Preference somewhat individualized…Preference somewhat individualized…
Myasthenic crisis: Myasthenic crisis: managementmanagement
PLEXPLEX Removal of anti AChR and antiMuSK AbsRemoval of anti AChR and antiMuSK Abs 1 session/day x 51 session/day x 5
No superiority of PLEX qd x 5 vs qod x 5No superiority of PLEX qd x 5 vs qod x 5 Rapid onset of action (3-10 days)Rapid onset of action (3-10 days) Need central line with associated complicationsNeed central line with associated complications
PTX, hemorrhage, line sepsisPTX, hemorrhage, line sepsis Caution in pts with sepsis, hypotension; may Caution in pts with sepsis, hypotension; may
lead to increased bleeding and cardiac lead to increased bleeding and cardiac arrhythmiasarrhythmias
Myasthenic crisis: Myasthenic crisis: managementmanagement
IVIGIVIG 0.4g/kg/day x 5 days0.4g/kg/day x 5 days Easily administered and widely availableEasily administered and widely available Long duration of action Long duration of action
May last as long as 30 daysMay last as long as 30 days Side effectsSide effects
Anaphylaxis in IgA deficiencyAnaphylaxis in IgA deficiency Renal failure, pulmonary edemaRenal failure, pulmonary edema Aseptic meningitisAseptic meningitis Thrombotic complications and strokeThrombotic complications and stroke
Myasthenic crisis: Myasthenic crisis: management management
Therapeutic effect of PLEX & IVIG is short-Therapeutic effect of PLEX & IVIG is short-lived…lasts weekslived…lasts weeks
Therefore, glucocorticoids started at high Therefore, glucocorticoids started at high dose (60 to 80 mg qd) as welldose (60 to 80 mg qd) as well
Onset of benefit at 2-3 wks, peaks at 5.5 mosOnset of benefit at 2-3 wks, peaks at 5.5 mos Initiation ass’d with transient worsening of Initiation ass’d with transient worsening of
weakness, serious in up to 50%weakness, serious in up to 50% Occurs 5-10 days after initiation & lasts 5-6 daysOccurs 5-10 days after initiation & lasts 5-6 days Resp failure requiring MV in up to 10%Resp failure requiring MV in up to 10% Concomitant use of PLEX or IVIG helps to prevent Concomitant use of PLEX or IVIG helps to prevent
this transient worseningthis transient worsening
GBSGBS Most common cause of acute or subacute Most common cause of acute or subacute
gen’d paralysisgen’d paralysis Monophasic AIDP: autoimmune attack against Monophasic AIDP: autoimmune attack against
surface antigens on peripheral nervessurface antigens on peripheral nerves Develops 5 days to 3 weeks after resp/GI Develops 5 days to 3 weeks after resp/GI
infection in 60%infection in 60% Campylobacter jejuniCampylobacter jejuni (26%) (26%) Viral URTI, influenzaViral URTI, influenza EBV, CMV, VZV, HIV, hep A & B, coxsackieEBV, CMV, VZV, HIV, hep A & B, coxsackie
Other precipitants: immunization, pregnancy, Other precipitants: immunization, pregnancy, surgery, Hodgkin’s diseasesurgery, Hodgkin’s disease
PresentationPresentation Sensory: Sensory:
distal paresthesias/numbness (earliest Sx.)distal paresthesias/numbness (earliest Sx.) Reduced vibration/proprioceptionReduced vibration/proprioception
Motor:Motor: SymmetricSymmetric; evolves over days to 1-2 wks; evolves over days to 1-2 wks AscendingAscending: LE before UE; : LE before UE; proximalproximal> distal> distal
Reflexes: reduced, then absentReflexes: reduced, then absent Autonomic instabilityAutonomic instability
Other: low backache very common, myalgiasOther: low backache very common, myalgias
InvestigationsInvestigations NCS/EMG:NCS/EMG:
Reduced conduction velocitiesReduced conduction velocities Loss of F wavesLoss of F waves Conduction block in motor nervesConduction block in motor nerves Reduced motor amplitudes: 2° axonal damage Reduced motor amplitudes: 2° axonal damage worse worse
Px.Px.
CSF: CSF: High protein (may be normal in first 2 days)High protein (may be normal in first 2 days) No cells or few lymphsNo cells or few lymphs
10% have 10-50 lymphs10% have 10-50 lymphs
ManagementManagement
Admit for observation (potential for Admit for observation (potential for deterioration)deterioration)
Determine if resp failure imminentDetermine if resp failure imminent
IVIG IVIG (0.4g/kg/d x 5 d) or (0.4g/kg/d x 5 d) or PLEX PLEX (4-6 Rx. q1-(4-6 Rx. q1-2d)2d) Equally effective (2012 AAN guideline)Equally effective (2012 AAN guideline) PLEX useful in first 2 weeks; benefit less PLEX useful in first 2 weeks; benefit less
clear after that…also more adverse effectsclear after that…also more adverse effects Steroids no proven benefitSteroids no proven benefit
Predictors of need for MV in Predictors of need for MV in GBSGBS
Time from onset to admission < Time from onset to admission < 7 days7 days
Inability to coughInability to cough Inability to standInability to stand Inability to lift elbows or headInability to lift elbows or head LFT increasesLFT increases Presence of autonomic dysfxnPresence of autonomic dysfxn
Sharshar T, Chevret S, Bourdain F, Raphael JC. Early predictors of mechanical ventilation in Guillain-Barre´ syndrome. Crit Care Med 2003;31(1):278–283.
CourseCourse Progression over 1-4 weeksProgression over 1-4 weeks Recovery: few wks to monthsRecovery: few wks to months Mortality 3-5%Mortality 3-5% Poor prognosis:Poor prognosis:
Resp failure requiring intubation Resp failure requiring intubation Advanced ageAdvanced age Very low distal motor amplitudes (axonal Very low distal motor amplitudes (axonal
damage)damage) Rapidly progressive weakness over 1 weekRapidly progressive weakness over 1 week
BotulismBotulism Toxin is a presynaptic blocker of Ach release
Onset of Sx. 12-36 hours after ingestion Prodrome: N/V, abdo pain, diarrhea, dry mouth Symmetric neurologic deficits
First develop acute cranial neuropathies (opthalmoplegia, can be total; B/L ptosis, dysphagia, dysarthria, facial weakness)
Blurred vision secondary to pupillary dilatation Descending muscle weakness No sensory deficits apart from blurred vision
Urinary retention/constipation (smooth muscle paralysis) Respiratory failureRespiratory failure is primary cause of death is primary cause of death
““Dozen Ds” of BotulismDozen Ds” of Botulism
dry mouthdry mouth diplopiadiplopia dilated pupilsdilated pupils droopy eyesdroopy eyes droopy facedroopy face diminished gag diminished gag
reflexreflex
dysphagiadysphagia dysarthriadysarthria dysphoniadysphonia difficulty lifting difficulty lifting
head head descending descending
paralysisparalysis diaphragmatic diaphragmatic
paralysisparalysis
Botulism Botulism Investigation: Investigation:
Foodborne: serum analysis for toxin by bioassay in mice
Analysis of stool, vomitus, and suspected food items may also reveal toxin
Infantile: isolation of C.botulinum spores & toxin detection in stool
EMGEMG Treatment: Treatment:
Equine serum heptavalent botulism antitoxin Children older than 1 year of age and adults
Human derived botulism immune globulin (BIG-IV or BabyBIG)
Infants less than 1 year of age
Key pointsKey points
20/30/40 rule20/30/40 rule Identify pts at risk for resp failure Identify pts at risk for resp failure
EARLY to avoid emergency intubationEARLY to avoid emergency intubation Don’t wait for pts to complain of Don’t wait for pts to complain of
dyspnea before doing bedside PFTsdyspnea before doing bedside PFTs