WikEM - User contributions [en]

Paroxysmal supraventricular tachycardia

2014-07-10T15:41:55Z

DanK:

==Diagnosis==

{| border="1"
| '''Sx'''
| '''Sinus Tach'''
| '''SVT'''
|-
| Hx
| volume loss
| sudden onset
|-
| PE
| dehydated
| CHF-like
|-
| <nowiki>*HR</nowiki>
| <180
| >180
|-
| Variability
| Yes
| No
|}

<nowiki>*In infants HR cuttoff = 220</nowiki>

==DDX==
#[[WPW]]
#[[Lown-Ganong-Levine Syndrome‎]]
#Mitral disease
#Digitalis toxicity
#Acute MI
#Pericarditis
#Hyperthyroidism
#Drugs (alcohol, tobacco, caffeine)

==Treatment==
#Unstable
##Synchronized cardioversion 0.5-1.0 J/kg
#Stable
##Vagal maneuvers
##Adenosine
###6mg IVP; 12mg IVP (if initial dose failed)
##Calcium-Channel Blockers
###Diltiazem 15–20mg IV over 2min
####May give 25mg IV if inadequate response after 15min
####If IV bolus worked start IV infusion at 5–20mg/hr
####Contraindications: Hypotension, CHF
###Beta-Blockers
####Metoprolol 5mg IV q5min x 3; give 50mg PO if IVP effective
####Esmolol 500mcg/kg IV over 60sec
#####May give repeat bolus if inadequate response after 2-5min
#####If effective start infusion at 50mcg/kg/min (titrate up to 300mcg/kg/min)

==See Also==
*[[V Tach vs. SVT]]
*[[Tachycardia (Narrow)]]
*[[ACLS: Tachycardia]]
*[[PALS: Tachycardia]]

==Source==
*Rosen's
*UpToDate

[[Category:Cards]]

Digoxin toxicity

2014-07-08T15:13:07Z

DanK:

== Background ==
*Mechanism of action
**Positive inotropic effect
***Inhibits Na-K pump -> incr extracelluar K, incr intracellular Na -> incr intracellular Ca
**Increases vagal tone
***Can lead to bradyarrhythmias (esp in young)
**Increases automaticity
***Can lead to tachyarrhythmias (esp in elderly)
*Renally cleared
*Hemodialysis does not work
*Can also be found in nature: Foxglove, Oleander, certain toads

=== Risk Factors ===

#Electrolyte Imbalance
##[[Hypokalemia|Hyperkalemia]], [[Hypomagnesemia]], [[Hypercalcemia]]
#Hypovolemia
#Renal insufficiency
#[[Cardiac Ischemia]]
#[[Hypothyroidism]]
#Meds
##CCBs, amiodarone

== Clinical Manifestations ==
===Cardiac===
#[[Syncope]]
#Dysrhythmias
##PVCs
##[[Bradycardia]]
##SVT w/ AV block
##Junctional escape
##Ventricular dysrhythmia, including bidirectional V-tach (esp in chronic toxicity)
#Digitalis Effect (seen with therapeutic levels; not indicative of toxicity)
##T wave changes (flattening or inversion)
##QT interval shortening
##Scooped ST segments with depression in lateral leads
##Increased U-wave amplitude
[[File:Digtox.jpg|center|700px]]

===GI===
#Often the earliest manifestation of toxicity
##[[Nausea/vomiting]]
##[[Abdominal Pain]]

===Neuro===
#[[Confusion]]
#[[Weakness]]
#Visual disturbances
##Yellow halos
##Scotomas
#Delirium

==Work-Up==
#Dig level
##Only useful prior to administration of [[Fab]] (otherwise becomes falsely elevated)
#Chemistry
#Urine output
#ECG (serial)

== Diagnosis ==
#Must use H&P and labs in combination; no single element excludes or confirms the dx
#Digoxin level
##Normal = 0.5-2 ng/mL (ideal = 0.7-1.1)
###May have toxicity even with "therapeutic" levels (esp w/ chronic toxicity)
##Measure at least 6hr after acute ingestion (if stable); immediately for chronic ingestion
###If measure before this may be falsely elevated due to incomplete drug distribution
#Potassium level
##Acute toxicity: Degree of [[Hyperkalemia]] correlates w/ degree of toxicity
##Chronic toxicity: K+ may be normal/low (concomitant diuretic use) or high (renal failure)

==DDX==
#CCB/BB toxicity
#Clonidine toxicity
#[[Organophosphate Toxicity]]
#Sick sinus syndrome

== Treatment ==
'''Calcium is theoretically contradindicated in Dig Toxicity (see [[Stone Heart]])'''
#'''[[Digoxin Immune Fab]]'''
##Indications
### Ventricular dysrhythmias
### Symptomatic bradycardias unresponsive to atropine
### Hyerkalemia >5.0 mEq/L secondary to digitalis intoxicaiton
### Coningestions of cardiotoxic drugs (beta-blockers, cyclic antidepressants)
### Acute digoxin ingestion of greater than 10mg in adults or greater than 4mg in children
### Acute digoxin ingestions with post distribution digoxin >10ng/mL (by 6 hours post ingestion)
### Chronic digoxin ingestion leading to steady state serum digoxin concentrations of >4ng/ml

#[[Activated Charcoal]]
##Questionable efficacy
##Only an adjunctive tx; NOT an alternative to fab fragment therapy
##Consider only if present within 1 hr of ingestion
##1g/kg (max 50g)

===Dysrhythmias===
#[[Digoxin Immune Fab]] is the agent of choice for all dysrhythmias!
#[[Cardioversion]] should only be used as a last resort (may precipitate V-Fib)
##Consider lower energy settings (25-50J)
#Bradyarrhythmias (symptomatic)
##[[Atropine]] 0.5mg IV
##[[Pacing]]
#Ventricular dysrhythmias
##[[Dilantin Load|Phenytoin]]
###Enhances AV conduction
###Phenytoin: 15-20mg/kg at 50mg/min
###Fosphenytoin: 15-20mg PE/kg at 100-150mg/min
##[[Lidocaine]]
###Decreases ventricular automaticity
###1-3mg/kg over several minutes; follow by 1-4mg/min
##[[Magnesium]]
###Many patients have [[Hypomagnesemia]] and labs can be unreliable.
###2-4 g IV over 20-60 mins

===[[Hyperkalemia]]===
#Treat with [[Fab]], not with usual meds
##Once Fab is given hyperkalemia will rapidly correct
#If [[Fab]] unavailable and hyperkalemia is life-threatening then treat with:
##Glucose-insulin
##Sodium bicarb
##Kayexelate
##Dialysis
##Calcium (controversial: some say dangerous, others say not)

===[[Hypokalemia]]===
#Chronic intoxication
##Raise level to 3.5-4
#Acute intoxication
##Do not treat (likely that potassium level is rapidly rising)

===[[Hypomagnesemia]]===
#Treat with 1-2g over 10-20 min
##Monitor for resp depresion
##Avoid in pts with:
###Renal failure
###Bradydysrhythmias/conduction blocks

==Disposition==
*Admit for signs of toxicity or history of large ingested dose; admit to ICU if [[Fab]] given
*Discharge after 12hr observation if asymptomatic after accidental overdose

==See Also==
*[[Digoxin Immune Fab]]
*[[Toxidromes]]
*[[Digoxin]]

== Source ==
*Rosen's
*Tintinalli
*ECG image by Dr. James Heilman
*Carol Rivers' 6th Edition

[[Category:Cards]]
[[Category:Drugs]]
[[Category:Tox]]

Digoxin toxicity

2014-07-08T15:10:39Z

DanK:

== Background ==
*Mechanism of action
**Positive inotropic effect
***Inhibits Na-K pump -> incr extracelluar K, incr intracellular Na -> incr intracellular Ca
**Increases vagal tone
***Can lead to bradyarrhythmias (esp in young)
**Increases automaticity
***Can lead to tachyarrhythmias (esp in elderly)
*Renally cleared
*Hemodialysis does not work
*Can also be found in nature: Foxglove, Oleander, certain toads

=== Risk Factors ===

#Electrolyte Imbalance
##[[Hypokalemia|Hyperkalemia]], [[Hypomagnesemia]], [[Hypercalcemia]]
#Hypovolemia
#Renal insufficiency
#[[Cardiac Ischemia]]
#[[Hypothyroidism]]
#Meds
##CCBs, amiodarone

== Clinical Manifestations ==
===Cardiac===
#[[Syncope]]
#Dysrhythmias
##PVCs
##[[Bradycardia]]
##SVT w/ AV block
##Junctional escape
##Ventricular dysrhythmia, including bidirectional V-tach (esp in chronic toxicity)
#Digitalis Effect (seen with therapeutic levels; not indicative of toxicity)
##T wave changes (flattening or inversion)
##QT interval shortening
##Scooped ST segments with depression in lateral leads
##Increased U-wave amplitude
[[File:Digtox.jpg|center|700px]]

===GI===
#Often the earliest manifestation of toxicity
##[[Nausea/vomiting]]
##[[Abdominal Pain]]

===Neuro===
#[[Confusion]]
#[[Weakness]]
#Visual disturbances
##Yellow halos
##Scotomas
#Delirium

==Work-Up==
#Dig level
##Only useful prior to administration of [[Fab]] (otherwise becomes falsely elevated)
#Chemistry
#Urine output
#ECG (serial)

== Diagnosis ==
#Must use H&P and labs in combination; no single element excludes or confirms the dx
#Digoxin level
##Normal = 0.5-2 ng/mL (ideal = 0.7-1.1)
###May have toxicity even with "therapeutic" levels (esp w/ chronic toxicity)
##Measure at least 6hr after acute ingestion (if stable); immediately for chronic ingestion
###If measure before this may be falsely elevated due to incomplete drug distribution
#Potassium level
##Acute toxicity: Degree of [[Hyperkalemia]] correlates w/ degree of toxicity
##Chronic toxicity: K+ may be normal/low (concomitant diuretic use) or high (renal failure)

==DDX==
#CCB/BB toxicity
#Clonidine toxicity
#[[Organophosphate Toxicity]]
#Sick sinus syndrome

== Treatment ==
'''Calcium is theoretically contradindicated in Dig Toxicity (see [[Stone Heart]])'''
#'''[[Digoxin Immune Fab]]'''
##Indications
### Ventricular dysrhythmias
### Symptomatic bradycardias unresponsive to atropine
### Hyerkalemia >5.0 mEq/L secondary to digitalis intoxicaiton
### Coningestions of cardiotoxic drugs (beta-blockers, cyclic antidepressants)
### Acute digoxin ingestion of greater than 10mg in adults or greater than 4mg in children
### Acute digoxin ingestions with post distribution digoxin >10ng/mL (by 6 hours post ingestion)
### Chronic digoxin ingestion leading to steady state serum digoxin concentrations of >4ng/ml

#[[Activated Charcoal]]
##Questionable efficacy
##Only an adjunctive tx; NOT an alternative to fab fragment therapy
##Consider only if present within 1 hr of ingestion
##1g/kg (max 50g)

===Dysrhythmias===
#[[Digoxin Immune Fab]] is the agent of choice for all dysrhythmias!
#[[Cardioversion]] should only be used as a last resort (may precipitate V-Fib)
##Consider lower energy settings (25-50J)
#Bradyarrhythmias (symptomatic)
##[[Atropine]] 0.5mg IV
##[[Pacing]]
#Ventricular dysrhythmias
##[[Dilantin Load|Phenytoin]]
###Enhances AV conduction
###Phenytoin: 15-20mg/kg at 50mg/min
###Fosphenytoin: 15-20mg PE/kg at 100-150mg/min
##[[Lidocaine]]
###Decreases ventricular automaticity
###1-3mg/kg over several minutes; follow by 1-4mg/min
##[[Magnesium]]
###Many patients have [[Hypomagnesemia]] and labs can be unreliable.
###2-4 g IV over 20-60 mins

===[[Hyperkalemia]]===
#Treat with [[Fab]], not with usual meds
##Once Fab is given hyperkalemia will rapidly correct
#If [[Fab]] unavailable and hyperkalemia is life-threatening then treat with:
##Glucose-insulin
##Sodium bicarb
##Kayexelate
##Dialysis
##Calcium (controversial: some say dangerous, others say not)

===[[Hypokalemia]]===
#Chronic intoxication
##Raise level to 3.5-4
#Acute intoxication
##Do not treat (likely that potassium level is rapidly rising)

===[[Hypomagnesemia]]===
#Treat with 1-2g over 10-20 min
##Monitor for resp depresion
##Avoid in pts with:
###Renal failure
###Bradydysrhythmias/conduction blocks

==Disposition==
*Admit for signs of toxicity or history of large ingested dose; admit to ICU if [[Fab]] given
*Discharge after 12hr observation if asymptomatic after accidental overdose

==See Also==
*[[Digoxin Immune Fab]]
*[[Toxidromes]]
*[[Digoxin]]

== Source ==
*Rosen's
*Tintinalli
*ECG image by Dr. James Heilman

[[Category:Cards]]
[[Category:Drugs]]
[[Category:Tox]]

Digoxin toxicity

2014-07-08T15:09:49Z

DanK: Just added indications for giving Dig Fab under the treatment. So it's all in one place.

== Background ==
*Mechanism of action
**Positive inotropic effect
***Inhibits Na-K pump -> incr extracelluar K, incr intracellular Na -> incr intracellular Ca
**Increases vagal tone
***Can lead to bradyarrhythmias (esp in young)
**Increases automaticity
***Can lead to tachyarrhythmias (esp in elderly)
*Renally cleared
*Hemodialysis does not work
*Can also be found in nature: Foxglove, Oleander, certain toads

=== Risk Factors ===

#Electrolyte Imbalance
##[[Hypokalemia|Hyperkalemia]], [[Hypomagnesemia]], [[Hypercalcemia]]
#Hypovolemia
#Renal insufficiency
#[[Cardiac Ischemia]]
#[[Hypothyroidism]]
#Meds
##CCBs, amiodarone

== Clinical Manifestations ==
===Cardiac===
#[[Syncope]]
#Dysrhythmias
##PVCs
##[[Bradycardia]]
##SVT w/ AV block
##Junctional escape
##Ventricular dysrhythmia, including bidirectional V-tach (esp in chronic toxicity)
#Digitalis Effect (seen with therapeutic levels; not indicative of toxicity)
##T wave changes (flattening or inversion)
##QT interval shortening
##Scooped ST segments with depression in lateral leads
##Increased U-wave amplitude
[[File:Digtox.jpg|center|700px]]

===GI===
#Often the earliest manifestation of toxicity
##[[Nausea/vomiting]]
##[[Abdominal Pain]]

===Neuro===
#[[Confusion]]
#[[Weakness]]
#Visual disturbances
##Yellow halos
##Scotomas
#Delirium

==Work-Up==
#Dig level
##Only useful prior to administration of [[Fab]] (otherwise becomes falsely elevated)
#Chemistry
#Urine output
#ECG (serial)

== Diagnosis ==
#Must use H&P and labs in combination; no single element excludes or confirms the dx
#Digoxin level
##Normal = 0.5-2 ng/mL (ideal = 0.7-1.1)
###May have toxicity even with "therapeutic" levels (esp w/ chronic toxicity)
##Measure at least 6hr after acute ingestion (if stable); immediately for chronic ingestion
###If measure before this may be falsely elevated due to incomplete drug distribution
#Potassium level
##Acute toxicity: Degree of [[Hyperkalemia]] correlates w/ degree of toxicity
##Chronic toxicity: K+ may be normal/low (concomitant diuretic use) or high (renal failure)

==DDX==
#CCB/BB toxicity
#Clonidine toxicity
#[[Organophosphate Toxicity]]
#Sick sinus syndrome

== Treatment ==
'''Calcium is theoretically contradindicated in Dig Toxicity (see [[Stone Heart]])'''
#'''[[Digoxin Immune Fab]]'''
##Indications
### Ventricular dysrhythmias (ventricular fibrillation, ventricular tachycardia)
### Symptomatic bradycardias unresponsive to atropine
### Hyerkalemia >5.0 mEq/L secondary to digitalis intoxicaiton
### Coningestions of cardiotoxic drugs (beta-blockers, cyclic antidepressants)
### Acute digoxin ingestion of greater than 10mg in adults or greater than 4mg in children
### Acute digoxin ingestions with post distribution digoxin >10ng/mL (by 6 hours post ingestion)
### Chronic digoxin ingestion leading to steady state serum digoxin concentrations of >4ng/ml

#[[Activated Charcoal]]
##Questionable efficacy
##Only an adjunctive tx; NOT an alternative to fab fragment therapy
##Consider only if present within 1 hr of ingestion
##1g/kg (max 50g)

===Dysrhythmias===
#[[Digoxin Immune Fab]] is the agent of choice for all dysrhythmias!
#[[Cardioversion]] should only be used as a last resort (may precipitate V-Fib)
##Consider lower energy settings (25-50J)
#Bradyarrhythmias (symptomatic)
##[[Atropine]] 0.5mg IV
##[[Pacing]]
#Ventricular dysrhythmias
##[[Dilantin Load|Phenytoin]]
###Enhances AV conduction
###Phenytoin: 15-20mg/kg at 50mg/min
###Fosphenytoin: 15-20mg PE/kg at 100-150mg/min
##[[Lidocaine]]
###Decreases ventricular automaticity
###1-3mg/kg over several minutes; follow by 1-4mg/min
##[[Magnesium]]
###Many patients have [[Hypomagnesemia]] and labs can be unreliable.
###2-4 g IV over 20-60 mins

===[[Hyperkalemia]]===
#Treat with [[Fab]], not with usual meds
##Once Fab is given hyperkalemia will rapidly correct
#If [[Fab]] unavailable and hyperkalemia is life-threatening then treat with:
##Glucose-insulin
##Sodium bicarb
##Kayexelate
##Dialysis
##Calcium (controversial: some say dangerous, others say not)

===[[Hypokalemia]]===
#Chronic intoxication
##Raise level to 3.5-4
#Acute intoxication
##Do not treat (likely that potassium level is rapidly rising)

===[[Hypomagnesemia]]===
#Treat with 1-2g over 10-20 min
##Monitor for resp depresion
##Avoid in pts with:
###Renal failure
###Bradydysrhythmias/conduction blocks

==Disposition==
*Admit for signs of toxicity or history of large ingested dose; admit to ICU if [[Fab]] given
*Discharge after 12hr observation if asymptomatic after accidental overdose

==See Also==
*[[Digoxin Immune Fab]]
*[[Toxidromes]]
*[[Digoxin]]

== Source ==
*Rosen's
*Tintinalli
*ECG image by Dr. James Heilman

[[Category:Cards]]
[[Category:Drugs]]
[[Category:Tox]]

Hyperkalemia

2014-07-06T23:05:50Z

DanK: /* Force Intracellular Shift */

== Background ==
*Defined as >6.0 mEq/L
*Consider pseudohyperkalemia (e.g. from hemolysis)
*Potassium secretion is proportional to flow rate and sodium delivery through distal nephron
**This is how loop & thiazide diuretics cause ''hypo''kalemia

== ECG ==
Changes NOT always predictable and sequential
*6.5 - 7.5 mEq/L: peaked T waves, prolonged PR interval, shortened QT interval
*7.5 - 8.0 mEq/L: widened QRS interval, flattened P waves
*10 - 12 mEq/L: sine wave, ventricular fibrillation, heart block

== Differential Diagnosis ==
#Pseudohyperkalemia: hemolyzed specimen, prolonged tourniquet use prior to blood draw, thrombocytosis or leukocytosis
#Redistribution
##Acidemia (see [[Diabetic Ketoacidosis (DKA)|DKA]])
##Cellular breakdown: see [[Rhabdomyolysis]]/[[Crush Injury]], hemolysis, see [[Tumor Lysis Syndrome]]
#Increased total body potassium
##Inadequate excretion: Acute or chronic renal failure, hypoaldosteronemia
##Drug-induced: potassium-sparing diuretic (spironolactone), angiotensin converting enzyme inhibitors (ACE-I), nonsteroidal anti-inflammatory drugs (NSAIDs)
##Excessive intake: diet, blood transfusion
#Other causes: succinylcholine, digitalis, beta-blockers

== Treatment ==
===Stabilize Cardiac Membranes: give if ECG changes, consider if K >7 mEq/L===
#Intravenous calcium: only if QRS interval prolonged
#Can give as calcium gluconate or calcium chloride
##Calcium gluconate 2 - 3 grams IV
###Only 1/3 the calcium compared to calcium chloride
###Give over 10 minutes: can cause hypotension due to osmotic shift
##Calcium chloride 1 gram IV
###Give over 1 - 2 minutes
###Extravasation is bad: use a good IV
###Usually given in code situations
##Duration of action: 30 - 60 minutes
##Use caution in patients taking [[Digitalis Toxicity|Digoxin]] although risk of [[Stone Heart]] may be unsubstantiated <ref>Erickson CP, Olson KR. Case files of the medical toxicology fellowship of the California poison control system-San Francisco: calcium plus digoxin-more taboo than toxic? J Med Toxicol. 2008 Mar;4(1):33-9</ref>
##Do serial [[EKG]]s to track progress: may need to give multiple doses

===Force Intracellular Shift===
#Intravenous insulin + dextrose
##Give 10 units regular insulin intravenously with 25 to 50 grams (1 - 2 50 mL ampules) of 50% dextrose (D50)
###May withhold dextrose if blood sugar >300 mg/dl (>17 mmol/L)
###Duration of effect: 4 - 6 hours
#Nebulized albuterol 5 - 20 mg
##Response is dose-dependent
##Peak effect: 30 minutes
##Duration of effect: 2 hours
#Intravenous sodium bicarbonate 50 ml of 8.4% solution (1 ampoule) given over 5 minutes
##Duration of effect: 1 - 2 hours
##More effective if patient is acidemic

===Remove from System===
#Intravenous furosemide (Lasix) 40 - 80 mg
#Sodium polystyrene sulfonate (Kayexylate): 30 gm oral or per rectum
##'''Controversial''', see: [[EBQ: Use of Kayexylate in Hyperkalemia]]
#Intravenous normal saline solution for volume expansion if dehydrated, rhabdomyolysis, diabetic ketoacidosis or other acidosis
#Definitive: hemodialysis

== See Also ==
*[[Electrolyte Abnormalities (Main)]]
*[[Acute Renal Failure]]
*[[Crush Syndrome]]

== Source ==
Tintinalli
Management Severe Hyperkalemia. Crit Care Med, 2008, 36:12
EMCrit Podcast #32
<references/>
[[Category:FEN]]
[[Category:Nephro]]