Perfusion

Perfusion

1. Definition

   • Normal physiologic process, heart pumps enough CO, to deliver nutrients and oxygen to tissues via capillaries and arteries.
     • Ischemia
       • Insufficient tissue O2
     • Infarction
       • Tissue death
     • Hypoxia
       • Lack of O2
     • Physiologic dead space
       • No perfusion but oxygenation is there, lung is working fine
         • cardiac problem or emboli
     • Pulmonary shunt
       • Proper perfusion, lack O2, lung problem, blood will shunt (redirect to area where there is more O2
     • Arterial line
       • To monitor BP and draw arterial blood gases
     • Central line
       • Tube that goes to superior vena cava
         • give major volume of fluid, blood ,meds

2. Heart sounds

   • Summation gallop" LUB-lub-dub-DUB (s3 and s4 present" Split S2: when pulmonic and aortic valves close at different times, audible during inspiration and expiration is abnormla, during inspiration and disappears w/ expiration is normal.
   • S1
     • "lub"
       • Closure of AV valves. Normal. Best hear at tricuspid and apical area. S1-S2 is systole, shorter than diastole.
   • S2
     • "dub"
       • Closure of semilunar valves at end of systole. S2-S1=diastole
   • S3
     • blood going into ventricles can cause vibrations, which causes s3 during diastole
     • "DUB"
       • Ventricular gallop, heard after S2. Normal in pregnant women, children, but not adults over 35-40yrs.
         • Rapid ventricular filling. Right sided best heard over tricuspid,left over apical.
   • S4
     • "LUB"
       • Atrial gallop, heard b4 S1, can be in healthy ppl, hear opening of valves.

3. Perfusion

   • Central perfusion
     • Blood movement generated by CO
       • Needs adequate cardiac fx, BP, BV
         • CO=SV x HR
           • SV: affected by contractility, preload, afterload
             • Preload: fluids, diuretics afterload: antihypertensive, vasopressors  decrease or increase CO
             • MAP= (CO X SVR) + CVP
               • mean arterial pressure: normal: (70-100mmHg) (below problem perfusing body) cardiac outpur systemic vascular resistance central venous pressure (passive, doesn't have a lot of impact)-dont usually include in equation
               • Impaired central perfusion
                 • Low cardiac output, systemic effect d/t oxygenated blood not reaching tissues.
                   • Severe: shock. Untreated: ischemia, cell injury, cell death
                     • Cardiogenic
                       • MI,tissue death, heart not pumping enough
                     • Septic
                       • Third spacing fluid building in tissues
                     • Hypovolemic
                       • Change in tissue permeability
                     • Increase: RR,BP, HR to compensate,
                       • Decrease perfusion to periphery to go to central (preserve imp organs)
                 • Assessment
                   • head to toe (focus on body system taht seems to be affected most)
                   • Diseases: MI, HF, Stroke, Afib, HTN, ventricular septal defect,sx (hypovolemia)
                   • Effect
                     • On other organs-renal failure (urine output-30mL/hr), fluid reg...
                     • S&S: change in LOC, fainting, diziness, loss of sensation, decrease in T, pallor, diaphoresis, central cyanosis,pain
                       • chest pain
                     • Manifestations across the lifespan
                       • Infants
                         • growth and development, immature CV sys
                         • Poor feeding
                         • Poor weight gain
                         • FTT
                         • Dusky color
                         • Vs, health assessment, congenital abnormalities
                       • Toddlers and children
                         • Berlin heart- can be on it fro 2-3 years while waiting fro heart translpant, can do same for adult but for 24-48 hrs (ECMO)- Extracapurial memebrane oxygenation (replacec heart and lungs)
                         • Squatting to breath
                         • Easily fatigued
                         • Developmental delays (failure to hit milestones)
               • EF
                 • percentage of blood pumped out by left ventricle (55-70%) normal
   • Tissue or local perfusion
     • Volume of blood that flows to tissues
       • Requires: patent vessels, hydrostatic pressure, capillary permeability
         • affected by wounds, burns, scars., pressure ulcers.
         • Impairement
           • D/t loss of vessel patency, permeability, central perfusion
             • Localized effect, impaired perfusion to affected tissues.
               • Ischemia, cell death if untreated
           • S&S
             • Decreased peripheral pulse, increased cap refill time, pain, necrosis, peripheral cyanosis, ischemia,emboli
               • wound site, leg (DVT) popliteal, brachial, carotid, poste PE
           • Assessment
             • head to toe (focus on area that seems to be affected the most
             • VS (what's going on?), LOC,GCS (esp stroke), CSMT, pulses, pain assessment, O2, edema, renal fx(hx)
               • CIRCULATION, SENSATION, MOVEMENT, TEMPERATURE
           • Diabetes (neuropathy), obesity, atherosclerosis, hyperlipedimia, peripheral vascular/artery disease, DVT

4. Populations at risk

   • Middle aged and older adults,
   • Infants and children (congenital),
     • patent ductis arteriosis: hoel in heart taht does not close
   • children and young adults (trauma),
   • individual (risk factors)
     • modifiable and non modifiable risk factors
   • women over 55
     • number one cause of death, more likely to die from heart disease than anything else
     • Women and heat disease
       • Altered perfusion
       • Canada: women 16% more likely to die from heart attack than men
         • stroke kills 32% more women than men
         • Heart disease and stroke kills 7x as many women as breast cancer
           • Women undiagnosed and untreated, different symptoms of MI,silent MI, indigenous pop, it's worse
   • Risk factors
     • Modifiable
       • Smoking
         • nicotine vasoconstricts, damage to BV
       • Elevated serum lipids
         • Atherosclerosis
       • Sedentary lifestyle
         • obesity
       • Obesity
         • atherosclerosis, increased risk of DMII
       • DM
         • Atherosclerosis
       • HTN
         • increase work of myocardium
     • Non modifiable
       • Age
         • increses with age
       • Gender
         • men > women
       • Genetics
         • family hx
     • Clinical management
       • Primary prevention modifiable risk factors
         • Smoking, nicotine use cessation
         • Diet modification
           • Reduce sodium, calorie
           • Increase fiber, H2O
         • Increase exercise
         • Weight control
           • Weight loss
         • Screening
           • 1.At what age should blood pressure screening begin? 2.How often should blood pressure screening occur? 3.Who should have lipid screening? How often?
           • BP screening
             • start at 18
             • Every 1-2yrs
           • Lipid screening
           • 12 Lead ECG
           • Asuscultation
             • Adventitious heart sounds
               • Valvular dysfx can lead to regurgitation
                 • back flow of blood in heart
                 • Which may lead to HTN, hypertrophy of a chamber, pulmonary HTN, cardiomyopathy, HF
           • Interventions
             • Independant
               • Based on nurse's assessment, clinical judgement
             • Collaborative
               • Dietition, nutritionist CABG:goals for  discharge: be able to walk 2 flights of stairs w/o getting out of breath with unasistance Berlin ehart- children Ideal- whats least invasive MI- want to decrease CO Cardiac arrest: want to increase CO Risk factor MI: emotional stress, heavy meals, strenuous activity, smoking
               • TX strategies depend on pt condition
                 • Diet and smoking sensation
                 • Increased activity
                 • Pharmacotherapy
                   • Impaired central perfusion
                     • Inotropes
                       • Positive
                         • Increase contractility
                           • Digoxin
                             • Cardiac glycoside, Antiarrythmics Slow electrical conduction at AV node- used tx arrithmias Antidote: Digibind N&V 1st sign of toxicity Narrow TI, long T1/2
                             • Block Na+/K+ ATPase pump, clock exit 3Na+, influx 2K+= high Na+ intracelular
                               • Activates Na+/Ca2+ exchanger= increase Ca2+, increase 3NAa+=contractility
                           • Calcium
                             • increase hr,co, contractility
                             • increase contractility, hr, co
                           • Epinephrine
                           • Dopamine
                       • Negative
                         • Decrease contractions and HR
                           • Tx: arrythiax, HTN, angina, afib, 
                           • CCB
                             • Decrease BP, vasodilate (increase blood flow), smooth muscle relaxation (coronary and vascular)
                               • Cardio selective: decrease HR, CO, COntractility- optimize contrctions, 
                               • Cardio-selective: Verampil (isoptin), Diltiazem (Cardizem)
                     • Antihypertensives
                       • ACE inhibiors (prils)
                         • 1st line tx HF Potent, works fast, short T1/2 can cause severe hypotension
                         • Decrease BP (vasodilation), BV
                           • Enalapril (Vasotec), Captopril (Capoten), Monopril, Ramipril (Altace)
                       • BB
                         • Decrease HR (negative chronotropy), decrease conduction rate, contractility (negative inotrophy)
                           • Atenolol (b1), metoprolol (b1,b2), propanolol (b1,b2)
                       • CCB
                       • NItrates
                         • Nitroglycerine (NitroStat), Nipride (Nitroprusside),
                           • Vasodilator,MI, decrease SV, relax heart, decrease chest pain (angina)
                       • Diuretics
                         • Loop, thiazide (hypokalemia), Spironolactone (potassium sparing)
                     • Antiarrythmics
                       • Decrease Na influx to decrease action potential
                       • Amiodarone (Cordarone)
                       • Procainamide
                     • Antianginal agents
                       • Nitroglycerine
                     • Vasopressors
                       • cardiac arrest
                       • Increase SVR to increase BP, vasoconstriction, work on alpha adrenergic receptors
                         • Dopamine
                         • Epinephrine
                         • NE
                     • Vasodilators
                       • O2
                       • Nitroprusside (Nipride)
                     • H and T of cardiac arrest
                       • Hypovolemia
                       • Hypoxia
                       • Hypo/hyperglycemia
                       • Hypothermia
                       • Hydrogen (acidosis)
                       • Toxins/Tablets
                         • OD
                       • Tension pneumothorax
                         • compress vena cava, lungs
                       • Thrombosis (MI)
                       • Thromboemoblism (PE)
                       • Trauma
                       • Tamponade (cardiac)
                   • Impaired local perfusion
                     • Anticoagulants
                       • Heparin
                       • LMWH
                         • Enoxaparin (Lovenox)
                         • Dalteparin (Fragmin)
                       • Apixaban
                         • Block thrombin receptor and factor Xa DVT
                       • Dabigatran (Pradaxa)
                         • Block thrombin receptor and factor Xa Prodrug
                       • Warfarin (Coumadin)
                         • Inhibit hepatic formation fo certain factors
                     • Thrombolytics
                       • Act on t-PA which converts plasminogen to plasmin in order to break up clot T1/2: 13-16 min IV within 6 hrs of onset of S&S
                       • Trauma, stroke, STEMI, Ischemic stroke, PE, DVT,
                         • Ateplase
                         • Reteplase
                     • Lipid lowering agents
                       • Statins, Vit B
                     • Vasodilators
                     • Antiplatelets
                       • Aspirin
                         • 81mg acute MI
                 • SX
               • Other
                 • Central perfusion
                   • Pacemaker insertion
                   • Electrical cardioversion
                     • Electrical current to reset heart rythm
                   • Ablation therapy
                     • Tumor
                   • Intra aortic ballon pump
                     • Deflated on systole, inflates on diastole
                       • heart gets more circulation, MI
                   • Cardiac valve sx
                     • Ventricular assistive device
                   • Cardiac transplantation
                     • HF
                 • Local perfusion
                   • CABG
                     • bypass or graft sx
                   • PTCA
                     • widen arteries, balloon and stent cardiac catheterization, femoral artery
                   • Endarterectomy
                     • Remove plaque

5. Common dx tests

   • Lab test(blood)
     • Myoglobin: heme protein helps transport O2, cardiac and skeletal muscles.  Onset: 1-3hrs Peak:4-12hrs Return to normal:12 hrs Negative result help rule out acute MI, increase doesn't help to indicate if there has been an MI-not specific
     • Electrolyte panel
       • Na, Ca, K+,Cl-, Mg, PO4,Glucose
         • Hemoglobin A1C
           • Over last 2-3 months, dx diabetes (6.5% or greater)
     • Cardiac markers
       • Peak, duration, check for MI
       • CK-MB
         • CK are isoenzymes, CK-MB is specific to the heart Onset:4-8hrs Peak:12-24hrs Return to normal: 3-4days Mass essay: (MB,MM,BB) onset: 2-3hrs Peak:10-18 hrs Return to normal: 3-4days Confirmation rather than diagnosis as peak is much later
         • Damage to cardiac cells
       • Troponin I
         • regulates myocardial contractin
         • Released c death, specific to heart
           • released 3-4hrs after, lasts 7-10days Three isomers: C, I ,T I and T are specific to the heart Reliable and critical markers Onset:3-4hrs Peak:4-24 hrs Return to normal: 1-3wks
       • LDH
         • Lactic dehydrogenase
         • Lactic acid build up
           • check for tissue death, not specific to heart
     • BNP
       • Brain natriuretic peptide
       • Sent by brain to stimulate ventricle to pump harder
         • HF, in increased ventricular workload high, low normal
     • Homocysteine
       • amino acid get from eating meat
       • Rise in heart disease
         • atherosclerosis, high,low or normal
     • CRP
       • Biomarker of inflammation
         • cancer, CAD, tumor, obesity, nonspecific high low or normal
     • Serum lipids
       • cholesterol, LDL, HDL, VLDL, Triglycerides
     • CBC
       • Hematocrit, platelets, hemoglobin, RBC
     • Coagulation panel
       • Coag Panel
       • PT
       • PTT
       • INR
       • Time it takes for blood to clot
         • Affect perfusion, can lead to DVT, too slow- at risk for bleeding (hypovolemia)
   • Radiographic studies
     • Chest X-Ray (CXR)
       • Arteriogram
     • ECHO
       • U/S of heart
         • Evaluate ventricular fx, can be used to measure EF, dx MI
     • TEE
       • Transesophageal exhocardiogram
       • Pt is sedated to visualise heart blood flow
         • U/S probe is swallowed, u/s of heart is taken from oesophageous
     • V-Q scan
       • Looking for PE, pulmonary shunt, dead space- check pulmonary perfusion
     • MITI
       • Myocardial perfusion test
       • Exercise + contrast dye + exercise to see changes in perfusion
   • Cardiac stress test
     • Exercise or pharmacological
     • ECG, walk, run, check normal sinus rythm normal ECG)
   • 12 Lead ECG
     • T wave inversion, ST elevation, normal or depressed, abnormal Q wave
       • Acute MI, chest pain

6. Key takeaways

   •     ▪Perfusion affects everything! Reflect on how it affects previously discussed concepts: gas exchange, pain, tissue integrity. ▪Start learning your common medications that impact perfusion (eg. antihypertensives, etc.) – know their mechanism of action ▪Focus on prevention, health promotion, and patient teaching wherever possible ▪Think about how perfusion affects other conditions, eg. Myocardial infarction and the concepts that apply     

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