BKAT ICU COMPREHENSIVE EXAM
QUESTIONS AND CORRECT ANSWERS
STUDY GUIDE
●● Cardiac Output (CO)
Answer: CO= HR x SV
CO= 4-8 L/min
HR=60-100
SV= 60-100 mL
Cardiac output is the amount of blood ejected in L/min; measures tissue
perfusion/assessment of blood flow. Affected by body size, O2 demand,
metabolic rate.
●● Preload (filling/volume)
Answer: Right: CVP: 0-8 mmHg
Left: PAD: 8-14 mmHg; PAWP 6-12 mmHg
Preload is the amount of end diastolic stretch on the myocardial muscle
fibers. The relationship of volume in the chambers and the compliance
of the chambers; think of a balloon!
*Starling's Law: The greater the stretch during diastole, the greater the
force of contraction in systole and the greater the cardiac output (CO)*
Low preload: fluids
High preload: Diuretics, nitrates, morphine
,●● Afterload (resistance)
Answer: Right: PVR (pulm vasc resistance) 150-250
Left: SVR (systemic vasc resistance) 800-1200; MAP: 60-90
Afterload is the resistance the ventricles must overcome in order to eject
blood forward. BP, SVR (left), PVR (right).
Low afterload: Vasopressors; levo, dopamine, neo, epi, vasopressin
[+alpha for vasoconstriction]
High afterload: Venodilators; nipride, captopril, flolan
[-alpha for vasodilation]
●● Contractility (squeeze)
Answer: SV: 60-100 ml/min
EF: >40%
Contractility is the inotropic state of the myocardium; depends on
healthy muscle, intact cardiac cell membrane and normal electrolyte
balance (Mg, K, Ca)
Increased: sympathetic stimulation (fight vs flight), vasoactive meds.
Decreased: myocardial hypoxia/ischemia, negative intropic medications.
Low contractility: Inotropes; dobutamine, milrinone
High contractility: antidysrhthmics; BB, Ca+ blockers.
●● Cardiac Index (CI)
, Answer: CI= 2.0-4.0
To calculate CI; CI=CO (4-8)/BSA
Cardiac index is the cardiac output in relation to the body size;
assessment of blood flow.
●● Stroke volume (SV)
Answer: SV= 60-100 mL/beat
To calculate SV; SV=CO (4-8)/HR
Stroke volume is the amount of blood ejected per beat; assessment of
pump function.
●● Ejection fraction (EF)
Answer: Normal EF: >40%
To calculate EF; EF= amount of blood ejected (SV)/amount of blood
available (EDV)
Ejection fraction is the % of available preload that is ejected as stroke
volume with each beat; efficiency of LV as a pump.
●● Mean arterial pressure (MAP)
Answer: Normal MAP: 70-110 mmHg
To calculate MAP; SBP+2(DBP)/3
MAP is the average BP throughout the cardiac cycle; used to titrate gtts;
consistent throughout arterial circulation regardless of location.
QUESTIONS AND CORRECT ANSWERS
STUDY GUIDE
●● Cardiac Output (CO)
Answer: CO= HR x SV
CO= 4-8 L/min
HR=60-100
SV= 60-100 mL
Cardiac output is the amount of blood ejected in L/min; measures tissue
perfusion/assessment of blood flow. Affected by body size, O2 demand,
metabolic rate.
●● Preload (filling/volume)
Answer: Right: CVP: 0-8 mmHg
Left: PAD: 8-14 mmHg; PAWP 6-12 mmHg
Preload is the amount of end diastolic stretch on the myocardial muscle
fibers. The relationship of volume in the chambers and the compliance
of the chambers; think of a balloon!
*Starling's Law: The greater the stretch during diastole, the greater the
force of contraction in systole and the greater the cardiac output (CO)*
Low preload: fluids
High preload: Diuretics, nitrates, morphine
,●● Afterload (resistance)
Answer: Right: PVR (pulm vasc resistance) 150-250
Left: SVR (systemic vasc resistance) 800-1200; MAP: 60-90
Afterload is the resistance the ventricles must overcome in order to eject
blood forward. BP, SVR (left), PVR (right).
Low afterload: Vasopressors; levo, dopamine, neo, epi, vasopressin
[+alpha for vasoconstriction]
High afterload: Venodilators; nipride, captopril, flolan
[-alpha for vasodilation]
●● Contractility (squeeze)
Answer: SV: 60-100 ml/min
EF: >40%
Contractility is the inotropic state of the myocardium; depends on
healthy muscle, intact cardiac cell membrane and normal electrolyte
balance (Mg, K, Ca)
Increased: sympathetic stimulation (fight vs flight), vasoactive meds.
Decreased: myocardial hypoxia/ischemia, negative intropic medications.
Low contractility: Inotropes; dobutamine, milrinone
High contractility: antidysrhthmics; BB, Ca+ blockers.
●● Cardiac Index (CI)
, Answer: CI= 2.0-4.0
To calculate CI; CI=CO (4-8)/BSA
Cardiac index is the cardiac output in relation to the body size;
assessment of blood flow.
●● Stroke volume (SV)
Answer: SV= 60-100 mL/beat
To calculate SV; SV=CO (4-8)/HR
Stroke volume is the amount of blood ejected per beat; assessment of
pump function.
●● Ejection fraction (EF)
Answer: Normal EF: >40%
To calculate EF; EF= amount of blood ejected (SV)/amount of blood
available (EDV)
Ejection fraction is the % of available preload that is ejected as stroke
volume with each beat; efficiency of LV as a pump.
●● Mean arterial pressure (MAP)
Answer: Normal MAP: 70-110 mmHg
To calculate MAP; SBP+2(DBP)/3
MAP is the average BP throughout the cardiac cycle; used to titrate gtts;
consistent throughout arterial circulation regardless of location.
