==Background==
*Autoantibody degradation, dysfunction, and blockade of acetylcholine receptor at the NMJ
*Thymus is abnormal in 75% of pts
**Thymectomy resolves or improves symptoms in most pts, especially those with a thymoma
*No sensory, reflex, pupillary, or cerebellar deficits

===Myasthenic Crisis versus Cholinergic Crisis===
#Myasthenic Crisis
##Respiratory failure is feared complication
##Much more common
##D/t med non-compliance, infection, surgery, tapering of immunosuppressants, meds
#Cholinergic Crisis
##Excessive anticholinesterase medication may cause weakness and cholinergic symptoms
##Rarely if ever seen w/ dose limitation of pyridostigmine to less than 120mg q3hr
##If on usual dose of meds assume exacerbation due to MG even w/ cholinergic side effects
#Edrophonium (Tensilon) test to distinguish the two is controversial
##Give 1-2 mg IV slow push. If any fasciculations, resp depression, or cholinergic symptoms within a few minutes, problem is likely cholinergic crisis (no more edrophonium). If no evidence of cholinergic excess, give total of 10 mg and observe improvement in case of myasthenic crisis.
## Side effects of Edrophonium: Arrhythmias, Hypotension, Bronchospasm
## Treatment: Atropine

==Clinical Features==
#Symptoms worsen with repetitive use / as the day progresses
##Ice Pack Test- should improve symptoms temporarily (usually ptosis; high specificity)
#Muscle weakness
##Proximal extremities
##Neck extensors
##Facial/bulbar muscles (dysphagia, dysarthria, dysphonia)
#Ocular weakness
##Ptosis
##[[Diplopia]]
##CN III, IV, or VI weakness

==DDX==
#Cholinergic crisis
#[[Lambert-Eaton Syndrome]]
#Botulism
#[[Thyroid Disorders]]
#Drug-induced myasthenia
##[[Antibiotics]] ([[aminoglycosides]], [[fluroquinolones]], [[clindamycin]], [[metronidazole]], [[macrolides]])
##Steroids
##Anticonvulsants (phenytoin, barbiturates, lithium)
##Psychotropics (haloperidol)
##Beta-blockers / calcium-channel blockers
##Local anesthetics
##Narcotics
##Anticholinergics (diphenhydramine)
##NMJ blocking agents (roc, sux)

==Treatment==
*Always evaluate tidal volume, FEV, negative inspiratory force, ability to handle secretions
#Meds
##Pyridostigmine
###If pt's usual dose has been missed the next dose is usually doubled
###PO route: 60-90mg q4hr
###IV route: 1/30th of the PO dose (2-3mg) by slow IV infusion
##Neostigmine
###0.5mg IV
#[[Intubation]]
##If possible avoid depolarizing AND non-depolarizing agents
###If pt requires paralysis use non-depolarizing agent at smaller dose
###If must use depolarizing agents, will need higher doses
#Plasmapherisis
#IVIG

==See Also==
*[[Lambert-Eaton Myasthenic Syndrome]]

==Source==
*Tintinalli's Emergency Medicine: A Comprehensive Study Guide, 7e (2010), Chapter 167. Chronic Neurologic Disorders

[[Category:Neuro]]

2013-07-16T03:32:53Z

Timothydavie: /* Source */

==Background==
#Most scorpion stings in North America result only in local pain.
#''Centruroides sculpturatus'', found in AZ, NM, TX, and CA, can cause systemic toxicity.

==Clinical Features==
#Local reaction
##Immediate and severe pain
#Systemic reaction
##Uncommon but can be severe, particularly in children
##Cranial nerve and somatic motor dysfunction can develop:
###Abnormal roving eye movements, blurred vision, pharyngeal muscle incoordination
###Can occasionally lead to respiratory compromise
##Tachycardia and severe agitation can also be present
#Grades of ''Centruroides'' envenomation
##Grade 1 - Local pain and/or paresthesias at site of envenomation
##Grade 2 - Pain and/or paresthesias remote from the site of the sting, in addition to local findings
##Grade 3 - Either cranial nerve/autonomic dysfunction or somatic skeletal neuromuscular dysfunction
###Cranial nerve dysfunction - Blurred vision, roving eye movements, hypersalivation, tongue fasciculations, dysphagia, dysphonia, problems with upper airway
###Somatic skeletal neuromuscular dysfunction - Restlessness, severe involuntary shaking or jerking of the extremities that may be mistaken for a seizure
##Grade 4 - Combined cranial nerve/autonomic dysfunction and somatic nerve dysfunction
#Without antivenom, symptoms typically last 24-48 hrs

==Treatment==
#Apply ice to area of sting
#Atropine
##May be given for hypersalivation and respiratory distress caused
###Contraindicated for foreign scorpion stings because may exacerbate adrenergic effects
#Antivenom
##Resolves clinical syndrome within 4hr

==See Also==
*[[Bites and Stings]]

==Source==
Tintinalli
Medscape: Scorpion Envenomation Treatment & Management <http://emedicine.medscape.com/article/168230-treatment>

[[Category:Environ]]

Scorpion envenomation

2013-07-16T03:31:59Z

Timothydavie: /* Clinical Features */

Scorpion envenomation

2013-07-16T03:28:31Z

Timothydavie: /* Background */

Scorpion envenomation

2013-07-16T03:27:55Z

Timothydavie: /* Background */

==Background==
#Most scorpion stings in N. America only result in local pain
#''C. sculpturatus'' found in AZ, NM, TX, and CA can cause systemic toxicity

==Clinical Features==
#Local reaction
##Immediate and severe pain
#Systemic reaction
##Uncommon but can be severe, particularly in children
##Cranial nerve and somatic motor dysfunction can develop:
###Abnormal roving eye movements, blurred vision, pharyngeal muscle incoordination
###Can occasionally lead to respiratory compromise
##Tachycardia and severe agitation can also be present
#Without antivenom symptoms last 24-48hr

==Treatment==
#Apply ice to area of sting
#Atropine
##May be given for hypersalivation and respiratory distress caused
###Contraindicated for foreign scorpion stings because may exacerbate adrenergic effects
#Antivenom
##Resolves clinical syndrome within 4hr

==See Also==
*[[Bites and Stings]]

==Source==
Tintinalli

[[Category:Environ]]

AHA recommendation changes by year

2013-05-09T23:21:49Z

Timothydavie: /* 2011 AHA Recommendation Changes */

'''For current guidlines see [[ACLS (Main)]]'''

==ACLS==
===2010 AHA Recommendation Changes===
*Routine use of cricoid pressure is NOT recommended
*Airway adjunct is recommended while performing ventilation
*Pulse/rhythm checks should only occur q2min
*Most critical component is high-quality compressions
*Atropine and cardiac pacing are NOT recommended for asystole/PEA

===2011 AHA Recommendation Changes===
*Bystandar CPR changes to CAB (Chest compressions, Airway, Breathing), instead of ABCs
*De-emphasize Drugs, Devices, and other Distracters
**Emphasize good CPR
*Atropine is removed for bradycardia
**Use an epinephrine drip or dopamine drip if needed
*Bicarbonate is out removed
**Except for specific toxidromes or renal failure
*Procainamide is first for '''stable''' VTach
**Continue to use amiodarone for unstable
*Use Amiodarone for UNSTABLE VTach
**Lidocaine is removed for unstable VTach
*New section on post arrest care
*No tPA for HTN Emergency BP (>200/110)
**Reduce BP first
*Special sections and algorithms added for 15 special situations (ie. pregnancy, stroke, PE)

==PALS==
===2010 AHA Recommendations===
*Use Heimlich for >1yr; back/chest thrusts for <1yr
*Treat shock w/ initial 20cc/kg bolus
**Repeat boluses up to total of 60 mL/kg; thereafter pressors should be started
*Do not routinely hyperventilate even in cases of head injury
*Provide family w/ option of being present during resuscitation
*IO is useful as initial vascular access
*Self-Adhering Electrodes
**Use largest size that will fit on child’s chest w/o touching
**When possible leave 3cm between electrodes
**Adult size for >10kg; infant size for <10kg
*Hypotension is defined as sys BP:
**<60 (0 to 28 days)
**<70 (1mo - 12mo)
**<70 + (2 X age in yr) (1-10yr)
**<90 (≥10yr)

==See Also==
*[[ACLS (Main)]]
*[[PALS (Main)]]

[[Category:Airway/Resus]]
[[Category:Cards]]

Von Willebrand disease

2013-04-10T20:56:16Z

Timothydavie: /* Source */

==Background==
*Most common inherited bleeding disorder
*vWF has two roles:
**1. Acts as cofactor for platelet adhesion
**2. Acts as carrier protein for factor VIII extending its half life
*vWD results from quantitative or qualitative dysfunction of Von Willebrand factor

==Clinical Features==
*Skin and mucosal bleeding
**Epistaxis, gingival bleeding, menorrhagia
*Hemarthrosis is unusual

==Diagnosis==
*Bleeding time: prolonged
*PT: normal
*PTT: normal-mildly prolonged
*vWF activity level: low

==Treatment==
*Avoid ASA, NSAIDs, heparin
*Intermediate purity factor VIII
**Goal to increase VWF activity by 50-100%
**Initial infusion of 20-40 IU/Kg
**High replacement doses may be indicated in more severe disease
*Platelet transfusion
**consider if replacement therapy instituted and persistent bleeding
*Desmopressin
**Induces release of vWF from endothelial storage sites
**0.3mcg/kg IV (max 20mcg) over 30min
*Aminocaproic acid
*Recombinant Factor VIIa
**Consider in type 3 VWD patients who have developed antibodies to VWF replacement
**Increased risk of thrombosis, especially in patients with coronary artery disease

==Source==
Tintinalli's Emergency Medicine: A Comprehensive Study Guide, 7e (2010), Chapter 230. Hemophilias and Von Willebrand Disease

Uptodate

[[Category:Heme/Onc]]

Hemophilia

2013-04-10T06:08:39Z

Timothydavie: /* Source */

== Background ==

*TREAT FIRST, Diagnose second. Assume bleeding until proven otherwise.
*Two types (clinically indistinguishable):
**Hemophilia A: Factor VIII deficiency
**Hemophilia B: Factor IX deficiency
*Substantial proportion (~1/3) of both types arise from spontaneous mutations
*X-linked disorders (overwhelmingly a disease of men)
*ICH is most common cause of hemorrhagic death
*Do not give NSAIDs or IM injections
*Avoid invasive procedures (e.g. central lines, LP)

== Clinical Features ==
*Pt does not need objective exam finding to treat. Subjective complaints are a harbinger of serious issues.
#Hemarthroses
##Leads to joint destruction and chronic arthropathy if not adequately treated
##Pts can reliably report when bleeding is occurring
#Hematomas
##Bleeding into soft tissues or muscle
###Neck (airway compromise)
###Limbs (compartment syndromes)
###Eye (retro-orbital hematoma)
###Spine (epidural hematoma)
###Retroperitoneum (iliopsoas bleeds and massive blood loss)
#Mucocutaneous bleeding
##Spontaneous bleeding uncommon from oropharynx, GI tract, epistaxis, or hemoptysis
#CNS
##Intracranial bleeding is most common cause of hemorrhagic death
##Subdural hematomas occur spontaneously or with minimal trauma
#Hematuria
##Common, usually not serious, source is rarely found

== Diagnosis ==
*Pain in soft tissue is bleeding until proven otherwise
*Paresthesias in legs - consider retroperitoneal bleed
*Easy bruising or bleeding out of proportion to the history of trauma
*Recurrent bleeding into joints and muscles
*Prolonged PTT; normal PT

== Work-Up ==
#Coags
##Only helpful for making the dx; once established unlikely to yield new information
##PT - normal
##PTT - abnormal (unless mild hemophilia)
##PTT s/p factor - should correct to normal
#Factor VIII assay
##Consider before treatment (for heme to follow)
##Normal: 50-150%
###Mild: >5%
###Moderate: 1-5%
###Severe: < 1%
#Head CT
##If HA, AMS, significant blunt head injury
#CT A/P
##Back, thigh, groin, or abd pain
#LP
##replete factor before attempting

== Treatment ==
*Always inquire whether pt has known inhibitors - may be refractory to conventional tx
**If so, obtain hematology consult before treatment
**If no know inhibitors, and pt not improving after replacement, order mixing study
***PTT will not correct if inhibitors present

=== Factor Replacement ===
#Major bleeding (GI, CNS, large muscle, trauma) requires factor replacement level 80-100%
#Moderate bleeding (soft tissue, small muscle, joint) requires 30-50%
#Diagnosis unknown
##Give FFP (contains VIII and IX)
##Each bag raises factor levels by 3-5%
#Hemophilia A
##Dose of Factor VIII = weight (kg) x % increased desired^ x 0.5
###After initial correction give half this dose q8-12hr
###1 IU/kg will increase the plasma concentration by 2%
##Desmopressin
###May be sufficient in pts with mild bleeding
###0.3mcg/kg IV over 15-30min
#Hemophilia B
##Dose of Factor IX = weight (kg) x % increase desired^
###After initial correction give half this dose 24 hr later
###1 IU/kg will increase the plasma concentration by 1%

^As integer, not percentage (e.g. for 25%, "25" not "0.25")

=== Specific Therapy (Factor VIII) ===

{| cellpadding="2" border="1" style="width: 522px; height: 546px;"
|-
! align="left" | TYPE OF BLEEDING
! align="left" | INITIAL DOSAGE
! align="left" | DURATION
! align="left" | COMMENT
|-
| align="left" colspan="4" | '''SKIN'''
|-
| align="left" | Abrasion
| align="left" | None
| align="left" | None
| align="left" | Treat with local pressure and topical thrombin
|-
| align="left" | Laceration
| align="left" | Usually none; if necessary, treat as minor
| align="left" | None
| align="left" | Local pressure and anesthetic with epinephrine may benefit; watch 4 hours after suturing; reexamine in 24 hours
|-
| align="left" | 
| align="left" | 
| align="left" | 
| align="left" | 
|-
| align="left" | Deep
| align="left" | Minor bleeding (12.5 mg/kg)
| align="left" | Single-dose coverage
| align="left" | May need hospitalization for observation; repeat may be necessary for suture removal
|-
| align="left" | '''EPISTAXIS'''
| align="left" | 
| align="left" | 
| align="left" | 
|-
| align="left" | Spontaneous
| align="left" | Usually none; may need to be treated as mild bleeding
| align="left" | None
| align="left" | Uncommon; consider platelet inhibition; treat in usual manner
|-
| align="left" | Traumatic
| align="left" | Moderate bleeding (25 mg/kg)
| align="left" | Up to 5–7 days
| align="left" | Trauma-related bleeding can be significant
|-
| align="left" colspan="4" | '''ORAL'''
|-
| align="left" | Mucosa or tongue bites
| align="left" | Usually none; treat as minor if persists
| align="left" | Single dose
| align="left" | Commonly seen
|-
| align="left" | Traumatic (laceration) or dental extraction
| align="left" | Moderate (25 U/kg) to severe (50 U/kg)
| align="left" | Single dose; may need more
| align="left" | Saliva rich in fibrin lytic activity; oral ε-aminocaproic acid (Amicar) may be given at 100 mg every 6 hr for 7 days to block fibrinolysis; check contraindications; hospitalize patients with severe bleeding
|-
| align="left" | '''Soft tissue/muscle hematomas'''
| align="left" | Moderate (25 U/kg) to severe (50 U/kg)
| align="left" | 2–5 days
| align="left" | May be complicated by local pressure on nerves or vessels (e.g., iliopsoas, forearm, calf)
|-
| align="left" colspan="4" | '''Hemarthrosis'''
|-
| align="left" | Early
| align="left" | Mild (12.5 U/kg)
| align="left" | Single dose
| align="left" | Treat as earliest symptom (pain); knee, elbow, ankle more common
|-
| align="left" | Late or unresponsive cases of early hemarthrosis
| align="left" | Mild to moderate (25 U/kg)
| align="left" | 3–4 days
| align="left" | Arthrocentesis rarely necessary and only with 50% level coverage; immobilization is critical point of therapy
|-
| align="left" | '''Hematuria'''
| align="left" | Mild (12.5 U/kg)
| align="left" | 2–3 days
| align="left" | Urokinase, the fibrinolytic enzyme, is in urine; with persistent hematuria an organic cause should be ruled out
|-
| align="left" | '''Major Bleeding'''
| align="left" | Major bleeding (50 U/kg)
| align="left" | 7–10 days or 3–5 days after bleeding ceases
| align="left" | In head trauma, therapy should be given prophylactically; early CT scan of head recommended for all
|}

==Disposition==
*Admit:
**Treatment requiring multiple factor replacement doses
*Bleeding in head, neck, pharynx, retropharynx, or retroperitoneum

==See Also==
*[[Coagulation Disorders]]
*[[Bleeding Treatment]]

== Source ==
*Tintinalli's Emergency Medicine: A Comprehensive Study Guide, 7e (2010), Chapter 230. Hemophilias and Von Willbrand Disease
*Rosen's

[[Category:Heme/Onc]]

Hemophilia

2013-04-10T06:07:02Z

Timothydavie: /* Background */

Von Willebrand disease

2013-04-10T06:06:05Z

Timothydavie: /* Source */

Von Willebrand disease

2013-04-10T06:05:48Z

Timothydavie: