Week Three Flashcards
What does K+ do in the body?
conduction velocity
helps to confine pacing activity to the SA node
Potassium value
3.5-5
Hyperkalemia (>5) ECG changes
tall, peak T wave
PVCs* that lead to VFib, that lead to cardiac standstill
prolonged P waves and PRI
flattened P waves or loss of P wave
Causes Of Hyperkalemia
excess K+ admin
K+ sparing diuretics
ACEI
ARB drugs
renal failure
acidosis
What hyperkalemia does to the body
decreases rate of ventricular depolarization (slows)
shortens repolarization (accelerates)
depresses AV conduction
Management
of
hyperkalemia
D50W and Insulin drip (forces K+ into cells so kidneys can filter out) (fast method)
Calcium Chloride ( temporary)
Kayexalate (cation exchange resin products into GI tract) (permanent)
Hemodialysis or Peritoneal dialysis
Hypokalemia (<3.5) ECG changes
PVCs, brady, ventricular tachy, (into VFib)
depressed T waves, inverted T waves, ST depression
U waves
2 and 3 degree heart blocks `
How does Hypokalemia effect the body
impairs myocardial conduction
prolongs ventricular repolarization
Causes of Hypokalemia
GI losses
renal dysfunction
alkalosis
diuretic therapy with insufficient replacement (LASIX)
chronic steroid therapy
Management of Hypokalemia
K+ replacement (10 meq per hour) THAT’S IT
high alert med
NEVER PUSH
monitor for phlebitis
What do you need to fix first hypomagnesium or hypokalemia
mag because that’s where K+ binds to
Magnesium values
1.3-2.4
Magnesium in the body
energy producer
essential for enzyme, protein, lipid, and carbs functions in the body
extracellular level essential for normal cardiac muscle function
Hypermagnesemia (>2.4) ECG Changes
rare
PCVs leading to VTach, leading to VFib
tall peak T waves
prolonged P waves and PRI
flattened P waves
Causes of Hypermag
renal dysfunction
tumor lysis syndrome (cancer)
overtreatment of low Mag levels
Treatment of Hypermag
IV calcium gluconate
Furosemide (Lasix)
hemodialysis
Hypomagnesemia (<1.3) ECG changes
prolonged PR and QT
presence of U waves
T wave flattening
widened QRS complex
What happens to the body in hypomag
impairs myocardial conduction
prolongs ventricular repolarization
causes of hypomag
insufficient intake
alcohol abuse
diuresis/diarrhea/ vomiting
rapid administration of citrated blood products (trauma from surgery)
-citrated binds to mag and pulls it out of the blood
Hypomag can lead to what rhythm?
torsades de pointes (sudden death, artery spasms, HTN)
management of hypomag
no pulse: 1-2 g in 10 mL D5W over 5-20 min
pulse: 1-2g over 5-60 min
evaluate renal function when administering Mg++
Calcium Levels
total: 8.5-10.5
ionized: 4.4-5.4
Functions of Calcium
vascular tone
myocardial contractility
cardiac excitability
hypercalcemia ecg changes
shortened QT interval
brady
heart block, BBB
what is seen in the body with hypercalcemia
strengthens contractility
shortened ventricular repolarization
causes of hypercalcemia
bone tumors
hypomagnesemia
endocrine disorders
excessive intake of Vit D or Ca
oral anti-acids
management of hypercalcemia
loop diuretics (furosemide 1mg/kg along with NS to maintain body water stability, along with K+ replacement
calcitonin (slower)
biphophonates
hemodialysis
hypocalcemia ecg changes
variable
brady
VTach
asystole
prolonged QT interval (leads to torsades de pointes)
what happens in the body with hypocalcemia
decreases myocardial contractility
reduces cardiac output
HoTN
decreases responsiveness to Digitalis
causes of hypocalcemia
post surgical, blood transfusions
alkalosis
shock
mag imbalances
what hypocalcemia what precautions do you put the pt on
seizure precautions
management of hypocalcemia
oral or IV replacement
calcium chloride
calcium gluconate (1-2 hr no push)
Pacemakers are?
a machine that delivers an electrical current to stimulate depolarization when the normal conduction pathway is damaged (can be temporary or permanent)
What would someone need a pacemaker?
symptomatic brady
severe asymptomatic brady
AV block
complete block
atrial flutter/AFib with slow ventricular response
sick sinus syndrome
tachy-Brady syndrome
sensing is
the ability to detect or see the patient’s intrinsic heart rhythm (cardiac depolarization)
if the rate is not where it needs to be it will cause the pacemaker to fire
pacing is
stimulates the heart to contract via myocardial cell depolarization
maintains primary control of pacing function of the heart
the “firing” action
atrial pacing causes what wave
p
ventricular pacing causes
QRS complex
Biventricular (dual-chamber) pacing you’ll see what
pacer spike followed by P wave then another pacer spike followed by QRS complex
Transcutaneous Pacemakers
through the skin - pads - only for 24 hours
Transvenous Pacemakers
through the vein into heart (RA to RV)
Epicardial Pacemaker
on the outside tissue of the heart (surgeries)
rate settings on pacemaker
60-80 (dr orders)
Output is equal to
milliamperes (mA)
how much electrical current is needed to depolarize the heart and capture a rhythm
start small
sensitivity is equal to
millivolts (mV)
the degree to which the pm is response to electrical activity of heart
AV interval control
time interval b/w atrial and ventricle pacing stimuli
temporary pacemaker care (three types)
avoiding shocking things that you don’t want to shock
wear gloves
cover wires
make sure you’re not burning the skin (use gel)
change transcutaneous pads 24 hours
put a new battery in the machine
check for loose connections
monitor for infections (drainage, redness, edema)
Permanent Pacemakers Post op care
OOB once stable
limit arm and shoulder activity
monitor insertion site for bleeding and infection
patient teaching important
watch for complications (infection, hematoma formation, pneumothorax, atrial or ventricular septum perforation, lead misplacement)
Permanent Pacemakers Patient and Caregiver Teaching
follow up app for pm function checks
incision care
arm restrictions
avoid direct blows
avoid high output generators
no MRI unless approved
microwaves ok
avoid antitheft devices
air travel
monitor pulse
pacemaker ID and medic alert ID
Failure to pace
Absence of pacing spikes and return to the underlying rhythm
what should you do when there’s a failure pace
check connections of pacing wire/extension cable attached to pulse generator
check/change battery
replace generator unit
remove source of electromagnetic interference
failure to capture
pacemakers spikes not followed by what they should (p or qrs)
what to do when there’s a failure to capture
increase mA settings until there’s a capture
over-sensing
absence of pacing spikes
lower sensitivity
undersensing
pacing spikes that occur after or are unrelated to the intrinsic rate
higher sensitivity setting
replace battery
reposition leads
how will you know a pm is working
increased cardiac output
increased BP
palpable pulses
improved color, temp, LOC
defibrillation
unsynchronized shock used to terminate ventricular fibrillation
2 MIN
allows SA node to resume pacemaker role
output is in what for defibrillation
joules or watts per seconds
how many joules do you start with
biphasic: 120 - 200
monophasic: 360 (one)
steps to defibrillation
start CPR while the defibrillator is getting set up
turn on and select energy
make sure sync is turned off (that’s for pacing)
apply gel pads
charge
put paddles on chest and make sure no one is touching the body
deliver charge
do you shock a pulse
no
do you shock asystole
no
synchronized cardioversion
low energy shock that goes with the R rhythm
sync button is on
sedate pt
70-75 joules (not 120)
rhythms that may be cardioverted
V tach with pulse
unstable SVT
unstable AFib
unstable Aflutter
nursing responsibilities for synchronized cardioversion
informed consent
NPO 6-12 hours
baseline 12 lead
O2 and BP monitoring
sedation as ordered
check that the cardiovertor is sensing like it should
document ( synchronized cardioversion, rhythm before and after, meds given, joules used, pt tolerance)
implantable cardioverter-defibrilator (ICD)
lead placed via subclavian vein to endocardium and the generator is placed in the skin (subcutaneously)
25 joules
when pt get ICD do they need to take their meds
YES teach to still take meds, ICD is last resort
