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41 Cards in this Set
- Front
- Back
Describe two types of myocardial trauma
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1. penetrating vs blunt chest trauma
2. Blunt trauma-Decreased C.O. due to myocardial restriction, blood loss, arrhythmias, myocardial cell death. |
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Myocardial contusion-Etiology
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Most often due to impact of chest against steering column or dashboard
-rapid deceleration - heart strikes anterior chest wall - right ventricle due to location - Compression between sternum and spinal column |
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manifestations of myocardial contusion
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-Precordial pain
-Arrhythmias -Friction rub -ECG changes -CXR show wide mediastinum -Cardiogenic shock -Enzymes? |
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How to diagnose Myocardial Contusion
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-CXR
-Serial ECGs and myocardial isoenzymes -Possible echocardiogram -Echo free space if tamponade |
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Interventions: Taking care of Myocardial Contusion Patients
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-Bed Rest with HOB Elevated
-Analgesics (MS) -Telemetry: treat symptomatic dysrhythmias -O2 -Assess for complications (MI, cardiac tamponade, CHF, ventricular aneurysm, pericarditis) Bedside ECG, hemodynamics, and activity tolerance monitoring? -Possible inotropic support? |
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Cardiac Tamponade
-Etiology |
• trauma
• surgery • infection |
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Cardiac Tamponade
-Blood fills pericardium & compresses heart (takes only small amount) |
• Becks Triad
• decreased filling • reduced C.O. • shock |
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Cardiac Tamponade - Manifestations
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• increased CVP--distended neck veins & muffled heart sounds
-if patient hypovolemic--may obscure • hypotension • narrowed pulse pressure • tachycardia • friction rub • sudden cessation or drop in C.T. drainage • widening mediastinum • decreased ECG voltage • u/o < 30 cc/h • unexplained anxiety/apprehension |
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Cardiac Tamponade
Interventions |
• Emergency situation-pericardiocentesis (unless post CABG, due to clot
formation) • elevate HOB • 02, IV access, I & 0, ECG & hemodynamic monitoring • thoracotomy |
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Cardiac Surgery
Myocardial Revascularization |
• Indications
• uncontrolled chest pain • lesions of LAD • 3+ vessel disease • alternative for transplantation • Angina and decreased exercise tolerance |
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Cardiac Surgery
Pre-Op |
Pre-Op
• Atenolol pm before surgery-reduces 02 consumption • Allopurinol pm before surgery-reduces reperfusion injury • Cefazolin at time of induction unless allergic to PCN or cephalosporins--then give Vancomycin |
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Cardiac Surgery
Surgical Procedures |
• Cardiopulmonary Bypass Pump
• Off Pump Cardiopulmonary Bypass • Done on Beating heart • Benefits • decreased inflammatory response • decreased neurologic, renal, or pulmonary complications • decreased need for blood transfusions • More cost effective • No difference in low risk patients one year cardiac outcomes • Risks • increased strokes |
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Cardiac Surgery
Operative technique stopped heart (not done on beating heart) |
• Cardiopulmonary bypass machine oxygenates and circulates blood
• heparin to prevent massive coagulation in C.B. machine • hypothermia: decreases metabolism & 02 needs • core temperature 82-89 F • heart temperature 46-59 F • Disadvantages to hypothermia • myocardial depression • ventricular dysrythmias • decreased cerebral flow (stroke) • platelet dysfunction (bleeding) • reperfusion injury • after hypothermia achieved, aorta is cross clamped • cold cardioplegia solution infused (K+) |
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Cardiac Surgery
Grafts: saphenous and IMA |
Attached to ascending aorta
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Cardiac Surgery
• After surgery: |
• After surgery:
• Blood rewarmed, air vented from heart chambers, cross-clamp removed, and blood perfuses the coronary arteries • Heart is restarted (may need to defibrillate or pace) • Temporary pacing electrodes placed on epicardium & brought out through chest wall • Chest tubes (mediastinal & pericardial space) • Sternum wired with stainless steel |
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Cardiac Surgery
Effects of Cardiopulmonary Bypass |
Effects of Cardiopulmonary Bypass
-Increased Capillary Permeability - Hemodilution - Altered Coagulation - Damage to Blood Cells - Microembolization - Increased Systemic Vascular Resistance |
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Cardiac Surgery
Postoperative Complications |
• MI
• Atelectasis • Tamponade: abrupt cessation of C.T. drainage |
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Cardiac Surgery
Postoperative Complications • Fluid & electrolyte imbalance |
• Fluid & electrolyte imbalance
• total body fluid increases • Increased capillary permeability • Treat: colloids (hetastarch or plasmante-pull fluids back into vasculature) • K+ increased or decreased • check K+ q2-4h for 1st eight hours |
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Cardiac Surgery
• Decreased C.O. Decreased contractility: |
• Decreased C.O.
• decreased preload to left ventricle • due to hypovolemia (intravascular) • keep P A WP greater than 10 to increase contractility and perfusion Decreased contractility: 1st 6-18 h post op • due to surgical manipulation, cardiopulmonary bypass machine, cardioplegia, ischemia due to cross clamping, reperfusion injury |
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Cardiac Surgery
increased L. V. Afterload |
Increased L. V. Afterload
• due to hypothermia, release of catacholamines, renin & angiotensin or Hx htn • increases wk load and 02 demand • treat: warming, vasodilators. |
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Cardiac Surgery
Postoperative Complications Blood pressure |
• Hypotension: if systolic pressure <90, saphenous grafts can collapse.
• Hypertension: if systolic pressure> 150, sutures may rupture or leak (hx HTN, catacholamines, pain, hypothermia) Epinephrine |
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Cardiac Surgery
Postoperative Complications Bleeding |
Bleeding
-• C.T. drainage should be dark, red, thin, serosanguinous without clots 200 ml/h for 1-2 hr, then decreasing • arterial: bright red, hypotension • venous: surgical problem or coagulopathy (thrombocytopenia, platelet destruction, antiplatelet medications before surgery.) • monitor for tamponade |
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Cardiac Surgery
Postoperative Complications Treatment: |
Treatment:
• control HTN, • keep C.T. patent, • peep 5-10 cm (increases intrathoracic pressure (decrease oozing)-but may decrease C.O.), • monitor PT, PTT, ACT, fibrinogen, platelets, bleeding times; • give FFP, platelets, • autotransfusion: if greater than 400 cc/h >3h --surgery |
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Cardiac Surgery
Postoperative Complications Dysrythmias: common • causes |
Dysrythmias: common
• causes • fluid and electrolyte disturbance • cardioplegia • cardiac manipulation • reperfusion |
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Cardiac Surgery
Postoperative Complications |
Post Op pain
-• Angina or MI may indicate graft failure -• Surgical--localized, sharp or dull, may increase with inspiration and movement. |
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Nursing Interventions
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Preoperative teaching
• Disease process • Description of surgery/risks • Post op course -• Visit SICU -• NPO -• Informed consent -• Pulmonary hygiene (TCDB, IS, splinting) -• Pain control -• Chest tubes -• Importance of ambulation |
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Myocardial surgery
Postoperative Care |
• ICU for 24 hours
• Expected outcomes: Pt. will maintain adequate ventilation, oxygenation, and hemodynamic stability • ventilator care • respiratory assess • ABGs • Connect cardiac monitor • Connect, zero, & level PA & arterial lines – • Assess and record waveforms -• 12 lead EKG -• Cardiac outputs -• Sv02: normal 60-80% -• C.T. Suction at 20 cm, no kinks or loops, continuous assessment of flow -• Urine output: initially 100-200 cc/h -• Hypothermia: vasoconstriction, rewarm slowly, avoid shivering -• Neuro assessment: pupils midline and reactive, limbs flaccid. Most regain consciousness in a few hours. Then assess movement & sensation. |
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Postoperative Care
IV meds |
-• manage IV vasoactive & inotropic medications
-• manage IV volume expanders • crystalloids: NS & Ringers lactate • colloids: hetastarch, albumin |
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Nursing Diagnoses
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• Inability to sustain spontaneous ventilation R/T anesthesia
• Decreased cardiac output • R/T • increased afterload • Myocardial depression • Cardiac tamponade • Dysrhythmias • Inappropriate fluid volume • Decreased myocardial tissue perfusion • Impaired skin integrity •Pain |
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Aortic or Mitral Valve Replacement
• Indications |
• decreased activity tolerance
• S0A • fatigue • Mechanical Valves • tilting disc • caged ball • bileaflet • Lifetime anticoagulation, click, prophylactic antibiotics • Biologic Valve • xenograft (animal) Porcine • homograft (cadaver) |
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Heart transplant
Indications |
• < 60 y/o with end-stage CHF
• No infections, cancer, alcohol, smoking, renal or respiratory problems |
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Heart transplant
Complications |
Complications
• $$ • donor availability • infection, rejection • immunosuppressant therapy for life |
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Heart transplant: what is done during heart transplant
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Cardiopulmonary bypass machine
aorta cross clamped Recipient's heart resected leaving atrial cuffs, posterior lateral walls, & great vessels |
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Heart transplant
Denervation |
Denervation: loss of sympathetic & parasympathetic nervous system
• Isoproterenol (inotrope & chronotrope) • atrial pacing wires • Atropine, carotid massage, & vagal maneuvers ineffective |
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Pacemakers
• Purpose- |
• Purpose--provides electrical stimulus when heart fails to generate or transmit its own.
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Pacemakers
• Indications: |
• Sinus node dysfunction
• AV block • Neurogenic syncope • pauses of 3 sec (carotid sinus pressure) • head tilting • cardiomyopathy • nonresponsive to drug therapy |
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Pacemakers
• Types |
Types
-• temporary -• permanent -• atrial -• ventricular -• A V sequential |
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Pacemakers
Terminology |
Terminology
-• pacing--PM ability to initiate electrical activity -• sensing--PM ability to sense heart's beats • oversensing: interprets noncardiac events as depolarization • under-sensing: fails to detect cardiac activity & fires inappropriately -• non-capture--heart doesn't transmit or respond to PM impulse • increase milliamperage • electrode placement • battery failure |
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Pacemakers
Nursing Care • Pre-op • Post-op |
• Pre-op
-• Informed consent -• NPO -• IV site -• Clean/shave insertion site • Post-op -• incision care -• VS -• PROM to affected side (q 48 hr.) -• CXR to check for complications (pneumothorax or pleural effusion) -• monitor ECG for PM function |
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Pacemakers
Nursing Care • Report |
• Report
-• failure to pace (no spike on ECG) -• failure to capture (spike but no QRS) -• improper sensing (firing when doesn't need to or not firing when should) -• runaway pacing (increased HR) -• hiccups--electrode misplacement |
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Pacemakers
Nursing Care -Patient Teaching |
• no contact sports
• no heavy lifting for 2 months • incision care • sx of infection • avoid tight fitting clothes • carry card • How PM works • battery change in 6-12 years • pulse taking (notify MD if HR < 5 beats below PM setting) • PM will set off airport security detectors • Do not hold electrical devices over PM site |