lecture #1 - hemodynamic monitoring Flashcards
what is systole?
contraction; when two ventricles contract causing blood to be ejected into aorta and pulmonary artery
what is diastole?
relaxation; blood vessels return blood to the heart in preparation for the next ventricular contraction
what are the properties of myocardial cell?
automaticity, conductivity, contractility, excitability
what is chronotropy?
the rate of contractions; positive chronotropic inc HR; negative chronotropic dec HR
what type of medications do you give when the heart is inc contracting (HF, HTN)?
beta-blockers (-“lol”) - metoprolol or atenolol
calcium channel blockers (-“pine” or “-zem”) - amlodipine or cadizem
antiarrhythmic drugs - amiodarone
what do inotropes do?
inc or dec force of contractions
what do positive inotropes do?
strengthen the heart’s contraction, pump more blood w/ fewer heartbeats (used in CHF, cardiomyopathy, recent MI, cardiogenic shock)
what do negative inotropes do?
weaken the heart’s contraction + slow the HR
tx CHF, HTN, arrythmias, chest pain + MI pt to red stress
what do dromotropy agents do?
affect the conduction speed in the AV node + subsequently the rate of electrical impulse
(+) pos inc conduction velocity (epi)
(-) neg dec velocity (vagal stim)
**important in tx cardiac arrythmias
what is cardiac output (CO)?
the amount of blood pumped by heart in one minute
what is preload?
the stretch of the ventricle when the heart is at the end of diastole (LVEDP) just before contraction
inc pre load - HF, valve disease, inc O2 demand
dec pre load - ACE, ARBS, diuretics, nitrates, CCB
dec pre load - shock, hemorrhage, dec blood return to heart
what is afterload?
the pressure the the heart must work against to eject blood during systole
inc afterload = inc BP + aortic stenosis
what is stroke volume?
the volume of blood pumped out of the left ventricle to the heart during each systolic cardiac contraction
norm (50 - 100 mL)
what is venous return?
the flow of blood back to the heart, the vol of blood that returns from the veins to the atria each minute
what is systemic vascular resistance (SVR)?
total peripheral resistance, amount of force exerted on circulating blood by the vasculature of the body
what is pulmonary vascular resistance?
the resistance against blood flow from the pul artery to the left atrium
what is the goal of hemodynamic monitoring?
to maintain adequate tissue perfusion
what factors affect HR?
autonomic innervation, hormones, fitness levels, age
what factors affect SV?
heart size, fitness levels, gender, contractility, duration of contraction, preload (EDV), afterload (resistance)
what does hemodynamic tell us?
the numbers can change before s/s
an inc in PAP means early indicator of: LV failure, pulmonary edema, fluid overload (hypervolemia)
*needs early tx
indications of hemodynamic monitoring?
critical illness, shock, hemodynamic instability, HF, unstable post op pt, ARDS, acute kidney injury, severe burn injury, trauma
expected reference ranges
Central venous pressure (CVP) = 2-6 mmHg
Pulmonary artery systolic (PAS) = 15-28 mmHg
Pulmonary artery diastolic (PAD) = 5-16 mmHg
Pulmonary artery wedge pressure (PAWP) = 6-15 mmHg
Cardiac output = 3-6 L/min
mixed venous (SVO2) = 60-80%
what are the pre-procedure nursing actions?
ensure pt’s understanding of procedure
assemble the pressure monitoring system
place pt in supine or trendelenburg position
level transducer w/ phlebostatic axis
what is the phlebostatic axis?
the anatomical point that corresponds to the RA and most accurately reflect’s a pt hemodynamic status
what are the post procedure nursing actions?
obtain CXR to confirm cath placement
continually mon respiratory + cardiac status
maintain line placement + integrity
observe + document waveforms; report changes as this can indicate catheter migration or displacement
place in supine position; HOB can be elevated 15-30 degrees
zero system to atmospheric pressure;monitor trends
**secure that PA catheter
nursing actions for infection/sepsis?
change dressings per protocol/document
use surgical aseptic technique (mask, sterile gloves, maintain sterile field)
mon for evidence of infection (fever, inc WBC)
collect specimens as ordered
admin antibiotics; IVFs; vasopressors
nursing actions for embolism?
use 0.9% sodium chloride for flushing system (heparin)
avoid introduction of air to prev embolism
recognize risk of pneumothorax w/ line insertion
recognize risk of arrythmias w/ insertion or line movement
what is hemodynamic instability?
systolic BO <= 90 mmHg
sustained low BP + dropping
GOAL: MAP > 60 mmHg
s/s of altered hemodynamic (preload)?
elevated: crackles in lungs, jugular vein distention, hepatomegaly, peripheral edema, taut skin turgor
dec: poor skin turgor, dry mucous membranes
R heart: CVP
L heart: PCWP
s/s of altered hemodynamics (afterload)?
elevated: cool extremities, weak pulses
decreased: warm extremities, bounding pulses
R heart: pulmonary vascular resistance
L heart: systemic vascular resistance
what drugs used to treat hemodynamic instability?
vasopressors
inotropic drugs
vasodilators
anti htn
loop diuretic
morphine
what do vasopressors do?
inc SVR + inc BP; induce vasoconstriction inc MAP
Phenylephrine, Norepinephrine, Epinephrine, Dopamine, Vasopressin
Vasopressors = vasoconstriction
what do inotropic drugs do?
inc CO, inc BP
pos (+) = Epinephrine, Norepinephrine, Dopamine, Dobutamine, Milrinone, Digoxin
neg (-) = Flecainide, Verapamil, Cardizem, Clonidine, Atenolol
what do vasodilators/anti htn do?
dec afterload + BP
what do loop diuretics do?
dec preload + BP
*if taken long term will dec afterload
what does morphine do?
dec VR + preload
why is cardiac output important?
it affects PERFUSION
tissue perfusion is dependent on blood flow
3 factors = circulating vol, cardiac pump function, vasomotor tone
*any inc in CO will inc BP = better blood flow
nursing actions for arterial line?
assess for signs of bleeding, dislodgement, hematoma, infection
assess for 5 P’s: pain, pallor, pulses, paresthesia, paralysis
if line gets dislodged = PRESSURE!
