NURS356 Exam 2 Study Guide Issues of the Heart Children with Cardiac Deficits Cardiovascular Overview Cardiac development begins at 4 weeks Completed by 8 weeks gestation many people don t even know they are pregnant at this point Chambers valves create a 1 directional blood flow determined by differences in pressures Blood takes the path of least resistance Changes After Birth The BIG switch oxygenation from placenta to lungs alveoli expand to blood flow to lungs capillaries are no longer constricted pulmonary vascular resistance change of pressures changes blood flow These changes are a direct result from the clamping of the cord crying First big breath pushes the amniotic fluid so that it is absorbed interstitially it is not supposed to drain out it is supposed to be absorbed Left atrial pressures increase with this closes forem ovale Right atrial pressures decrease which increases vascular resistance increases pulmonary blood flow which improves oxygenation Closure of ductus arterious can take up to 10 days after birth BP isn t affected unless there is a persistent fetal circulation or hypoxic hit Changes During Infancy Heart is large in relation to body size but body catches up L side walls thicken with development this right sided pressures Try to do everything right blood always takes the path of least resistance Pressures within the Chambers Fetal elevated right side pressure Adult left side higher pressure Cardiac Physiology Cardiac output HR X stroke volume Best way to determine cardiac output during assessment is by checking pulses upper and lower should be equal strong easy to paplate 1 NURS356 Exam 2 Study Guide preload volume of blood returning to heart Lasix impacts preload decreasing volume of blood flow returning to the heart afterload resistance ventricles must pump when ejecting blood contractility pump efficiency impacts tissue perfusion kidney function digoxin strengthens and slows contract of heart thus increasing cardiac output Fun Facts on Heart Rate Regulated by the autonomic nervous system responds to organ needs emotions So what is NORMAL Hr throughout childhood as hr blood pressure LOOK ACROSS AGE IN BOOK Sinus arrhythmias are NORMAL in children Will hear when child holds breath and then lets it out slowing of heart rate heard Or if they ve been crying and then settle down you will hear one Pediatric Cardiac Deficits Congenital heart defects Anatomic abnormalities at birth Result in abnormal cardiac function Acquired cardiac disorders Abnormalities that occur after birth Seen in a normal heart Result from infection autoimmune response environment or familial tendencies Congenital Heart Disease 8 in every 1000 births 32 000 born in US each year 35 recognized types however 9 comprise 90 of all CHD seen W o treatment 60 die 30 die as infants Causes exposure of mom while pregnant Maternal rubella or virus genetic problems Poor maternal nutrition drugs particularly cocaine and heroin diabetes advancing maternal age 35 maternal infection 2 NURS356 Exam 2 Study Guide Classification of CHD Classification by physical characteristic Cyanotic defects tetralogy of Fallot Always diagnosed at birth or closely after Don t respond well to oxygen therapy Loud roaring murmurs Polycythemia and hypoxemia Lows sats RBC production over time CBC count clotted Thick viscous blood These kids can have a stroke Acyanotic defects PDA VSD stenosis Age 4 7 days Murmurs but not loud roaring May not experience cyanosis Show early signs of congestive heart failure activity intolerance cant finish feeding b c they become tired toddler not growing not running around Wet breath sounds Commonly have URI Clinical consequences hypoxemia with polycythemia cyanotic congestive heart failure acyanotic Signs to Alert to Possible CHD Low apgar scores murmur anoxic or hypoxic event poor feeder Increasing respiratory distress Tachypnea dyspnea weak cry Insidious onset Metabolic acidosis changes of BP changes in collateral circulation Mottled legs and nothing else wrong altered growth development fussy irritable lack of energy Cyanotic Heart Defects Decreased arterial oxygen saturation Desaturated blood circulates systemically 3 types of defects causing cyanosis obstruction R L shunt Tetralogy mixing within heart hypoplastic heart parallel circulation transposition all result in ineffective pumping and cardiac output low pulse oximetry reading at birth and loud murmur mixing of blood 3 NURS356 Exam 2 Study Guide ruled out by looking at preductal and postductal pulse oximetry preductal always the right hand postductal put pulse ox on any other extremity you will notice the oxygenation on preductal will be MUCH HIGHER then the postductal oxygenation d t the mixing of blood ruled out by use of hyperoxygen test deliver 100 oxygen to baby with cyanotic heart defect and see if it changes preductal postductal oxygenation doesn t change after 10 minutes cyanotic heart defect EKG done Compensatory Mechanisms Ineffective pumping causes an force cardiomegaly hypertrophy of ventricles Tachycardia to cardiac output heart working harder to push out more blood RBC production to O2 carrying capacity polycythemia with Hct more than 60 pulmonary vascular resistance viscosity of the blood causes workload for the heart DANGER can go into cardiac collapse Clinical Manifestations Polycythemia anemia Because of the blood concentration it is difficult to pick up that their RBC count is not right Clubbing of fingers toes secondary to chronic decreased arterial oxygenation Squatting to relieve chronic hypoxia because it decreases the distance of cardiac output from heart to overall organs Hypercyanotic spells r t crying feeding pooping temper tantrum they turn navy blue extremely painful 40 of these spells require 100 O2 nurses tend to panic PUT IN KNEE CHEST POSITION OR SQUAT DELIVER 100 O2 and MORPHINE FOR PAIN At risk for strokes emboli brain infarcts particularly if they have many hypercyanotic spells or if their HR increases and it unchecked Nursing Interventions once it is diagnosed by echocardiogram Prostaglandin therapy until repaired IV hung vasodialation to improve oxygenation keeps ductus open until they can have surgery Managing hypercyanotic spells knee chest position 100 O2 morphine to reduce spasm hydration to reduce viscosity prevent stroke 4 NURS356 Exam 2 Study Guide Palliative shunt Blalock Gortex PDA so that they do not have to remain of prostaglandins PREVENT DEHYDRATION MANAGE HYPERCYANOTIC SPELLS