In general, what is the goal of critical care? - Answers- enhance O2 delivery and decrease O2 demand SUPPLY vs. DEMAND general reasons for increased HR - Answers- sympathetic response OR tissue hypoxia physiologic reason for increased RR - Answers- tissue hypoxia OR metabolic (lactic) acidosis general reason for increased RR - Answers- sympathetic response OR tissue hypoxia OR metabolic (lactic) acidosis What is a normal pulse pressure? What does the pulse pressure indicate? - Answersnormal pp is about 40 and generally indicates cardiac index narrow pp = hypovolemia, drop in CO widening pp = neurogenic shock, increased ICP How to tell generally which type of shock you are looking at based on vital signs? - Answers- * hypovolemic, cardiogenic - narrowed PP, increased HR (check the H&P, echo - does this person have a condition which would indicate potential for cardiogenic shock?) * neurogenic - widened PP, decreased HR * anaphylactic, septic - BP down, HR up Normal Hemodynamic and Oxygenation Parameters - Answerscoronary arteries - Answers- RCA, LCA > LCfx, LAD What structures are supplied by the RCA? - Answers- right atrium, right ventricle, posterior left ventricle (left ventricular inferior wall), SA node, AV node, top of septum with bundle What types of dysrythmias are expected in an inferior wall MI? In a 12-lead EKG, which leads are identified? - Answers- leads II, III, aVf (what structures are supplied by the RCA, which feeds the left ventricular inferior wall?) bradycardias and heart block > why? because RCA supplies this area Associated with AV conduction disturbances: 2nd-degree Type I, 3rd-degree heart block, sick sinus syndrome (SSS), and sinus bradycardia Development of systolic murmur: mitral valve regurgitation (MVR) secondary to papillary muscle rupture (Posterior papillary muscle-tethering distance is significantly greater in inferior compared with anterior myocardial infarction.) Tachycardia associated with inferior MI → higher mortality Also associated with RV infarct and posterior MI Use beta blockers and NTG with CAUTION *** What are important considerations in RV infarct? - Answers- A right-sided ECG may demonstrate the ST changes. Treatment - Fluids - Positive inotropes Avoid - Preload reducers → nitrates, diuretics - Caution with beta blockers, often cannot give initially due to hypotension What structures are supplied by the LCA? - Answers- Left Mainstem LCfx - left atrium, high lateral left ventricle LAD - 2/3 septum, anterior left ventricle, apex What types of dysrythmias are expected in an anterior wall MI? - Answers- tachy dysrhythmias - vtach, vfib 2nd degree Type II, RBBB >> ominous sign possible ventricular septal defect What are coronary arteries dependent on for filling? - Answers- diastolic time diastolic BP (DBP) Cardiac Output Calculation - Answers- CO = HR x Stroke Volume What are the components of blood pressure? - Answers- BP = CO x SVR What is stroke volume? Normal? - Answers- preload (volume), afterload ( right PVR / left SVR), contractility; 50-100 ml/beat What is effect of nitroglycerin? - Answers- vasodilator (coronary arteries and systemic venous system) How can you manage preload in a patient pharmacologically? - Answers- if their kidneys are working, you can try diuretics (lasix, bumex) if not, try vasodilators (nitro, natrecor) How can you manage (high) afterload in a patient pharmacologically? (Mgt of HF) - Answers- nipride A, B, Cs *A - ace inhibitors (-pril), angiotensin receptor blockers (-sartan), alpha antagonist (hydralazine, cardura) *B - beta blockers *C - CCBs (norvasc, nicardipine) How can you manage (low) afterload in a patient pharmacologically? - Answerspressors: norepinephrine, vasopressin, neosynephrine (levo, vaso, neo) also high dose epi, high dose dopamine, What is a potential complication of using vasopressin in managing shock states? - Answers- vasopressin is a coronary artery constrictor, so use sparingly in people with cardiac histories How can you manage stroke volume in a patient pharmacologically? - Answersinotropes: milrinone, dobutamine, digoxin (the only PO option), dopamine What is a potential side effect of ace inhibitors? - Answers- angioedema / cough Auscultory points for heart sounds? - AnswersWhat do S3 and S4 heart sounds signify? What do all heart sounds signify and where are they best heard? - Answers- S4: myocardium is non-compliant/stiff; loudest at apex with bell. (ischemia, infarct, htn, vent hypertrophy, aortic stenosis) S1: ventricular systole (mitral/tricuspid shut); loudest at apex S2: ventricular diastole (aortic/pulmonic shut); loudest at base, louder with PE S3: volume overload - too much volume in ventricle; loudest at apex with bell. (HF, pulm htn, cor pulmonale *rt side HF, insufficiency) What typically causes low pulmonary pressures? - Answers- hypovolemia What is the most available pulmonary vasodilator available for use? - Answers- oxygen Cardiac Index - Answers- CO / BSA = Normal: 2.5-4.0 L/m2/min; considers body size in relation to CO, more meaningful than CO What are two major functions of ventricular diastole? - Answers- ventricular filling, coronary artery perfusion Preload (definition and assessment) - Answers- Volume of blood in the ventricle at the end of diastole. Assmt: RV - CVP, RA pressure