FACTORS THAT REQUIRE HEMODYNAMIC
Preload – the amount of myocardial stretch just
before systole caused by the volume of blood
presented to the ventricle.
Venous return – the volume of blood that enters the
Compliance - the elasticity or the amount of “give” when
blood enters the ventricle.
Afterload – the amount of resistance to ejection of
blood from a ventricle
Contractility – the force of ventricular contraction;
related to the status of myocardium.
The determinants of stroke
The SV is determined by
the amount of preload presented
to the ventricle, the amount of
afterload or resistance to
ventricular ejection, and the
strength of cardiac contractility.
NONINVASIVE ASSESSMENT OF CARDIAC
Measuring jugular venous distention –
estimates right ventricular preload
Positive hepatojugular test – identifies
elevated left ventricular preload
Mean arterial blood pressure - an
approximate indicator of left ventricular
Activity tolerance – may be used as an
indicator of overall cardiac functioning.
JUGULAR VENOUS DISTENTION
POSITIVE HEPATOJUGULAR TEST
Mean arterial blood pressure
•is cardiac output
•is systemic vascular resistance
•is central venous pressure
INVASIVE ASSESSMENT OF CARDIAC
Pulmonary artery catheter - is diagnostic
procedure used to detect heart anomalies,
monitor therapy, and evaluate the effects
- It allows direct, simultaneous
measurement of pressures in the right
atrium, right ventricle, pulmonary artery,
and the filling pressure ("wedge" pressure)
of the left atrium.
Occurs when the heart ceases to produce
an effective pulse and circulate blood.
It may be caused by a cardiac electrical
event such as ventricular fibrillation,
progressive profound bradycardia, or when
there is no heart rhythm at all (asystole).
It may follow respiratory arrest
It may also occur when electrical activity
is present but there is ineffective cardiac
contraction or circulating volume, called
pulseless electrical activity (PEA).
PEA can be caused by hypovolemia,
massive pulmonary embolism, myocardial
infarction and medication overdose.
Loss of consciousness, pulse and BP
Ineffective respiratory gasping may occur
The pupils of the eyes begin dilating within
Seizures may or may not occur
For adult and child: carotid pulse is assessed
For infant: brachial pulse is assessed
Cardiopulmonary resuscitation (CPR)
- Provides blood flow to vital organs until effective
circulation can be re-established.
It consists of the following steps:
Airway – maintaining an open airway.
Breathing – providing artificial ventilation by
Circulation – promoting artificial circulation by
external cardiac compression; administer
Defibrillation with standard defibrillator
or autonomic external defibrillator (AED)
for ventricular tachycardia and
MEDICATIONS USED IN CPR
Oxygen – improves tissue oxygenation and
• Use 100% FiO2 during resuscitation.
• Recognize that no lung damage occurs
when used for less than 24 hours.
• Monitor dose by pulse oximeter.
Epinephrine (Adrenalin) – increases systemic
vascular resistance and blood pressure;
improves coronary and cerebral perfusion
and myocardial contractility.
Administer 1 mg every 3 – 5 minutes by IV
push or through the ET tube.
Avoid adding to IV lines that contain alkaline
solution (eg. Bicarbonate)
Vasopressin (Pitressin) – increases systemic
vascular resistance and BP
• Give 40 U IV one time only
Atropine – blocks parasympathetic action;
increases SA node automaticity and
• Give rapidly as 2.0 to 2.5 mg IV push or through
the ET tube
• Be aware that less than 0.5 mg in the adult can
cause the heart rate to decrease to a worse
• Monitor patient for reflexive tachycardia.
Sodium bicarbonate (NaHCO3) – corrects
Administer initial dose of 1 mEq/kg IV; then
administer the dose based on the base deficit
calculated from arterial blood gas values.
Recognize that to prevent development of
rebound metabolic alkalosis, complete
correction of acidosis is not indicated.
Magnesium – promotes adequate
functioning of the cellular sodiumpotassium pump.
• May give diluted over 1 – 2 minutes or IV
• Monitor for hypotension, asystole,
bradycardia, respiratory paralysis.