急性心衰和心源性休克ppt课件

Acute HF/Cardiogenic shock
MI
HTN
MI
Death
I
II
Heart Failure
III
IV
Drugs
Valve Dz
Shock
Relationships/Key Terms
• • • • • • Cardiac output= HR x Stroke volume MAP= CO x SVR Preload Contractility Afterload Frank-Starling relationship
• Patient perfusing at expense of higher pressure • Gradually lower PAOP without causing adverse effects
– Avoid over-shooting or else! – Avoid prompting reflex mechanisms
Lower pcwp ( preload) with nitrates, diuretics
CI 2.2
Subset III:
Subset IV:
0
18
PCWP Mortality increases from set to set! See figure 13-7 in text.
Subset Two
• Typically involves diuretics, nitrates and (more recently) nesiritide.
Nitroglycerine
• • • • Preferred preload reducer Decreases PCWP, decreases pulmonary congestion Cheap, short T50, easily titrated Used in combination with inotropes in patients with pulmonary congestion and reduced LV function • Coronary dilation at high doses: useful in patients with ischemia • Avoid if elevated intracranial pressure • Tolerance in 12 - 72 hours
Diuretics
• Vasodilation: 5-10min, prostaglandin mediated • Diuresis: 20+ minutes • Reduction in preload in patients with volume depletion or decreased diastolic function may be harmful • Does not improve CI/CO in most patients (curve flat) • Role: use carefully to reduce symptoms of congestion without compromising cardiac output
– slams the screen door before all the kids get out
• Chronic HF patients are very succeptable to increases in afterload
Approach to patient
• Assess status: s/s, target organ damage • Address alterable causes
– vasoconstrictors: epi, NE, AngII, TxA2, vasopressin – vasodilators: PGI2, NO, adenosine, natriuretic peptides
Normal reflex mechanisms
• Increase preload: Na/H20 retention, RAAS • Increased contractility: adrenergic outflow (NE) • Increased afterload: norepi, AngII, endothelin, vasopressin
CI
2.2 0
STD treatment/monitoring
Subset III:
Subset IV:
18
PCWP Mortality increases from set to set! See figure 13-7 in text.
Subset One
• • • • Patient symptomatic Warrant full work-up Address other cause Maximize oral therapy for chronic HF
– Drugs – Diseases/conditions
• Assess fluid status- over or under hydrated? • Assess severity and initiate pharmacotherapy • Adjust moment by moment
Patient monitoring
• • • • • • Vital signs Acid/base Oxygenation Hydration Renal function Swan line
– PCWP – Cardiac output
Approach by hemodynamic subset
Subset I: perfusing, no pulmonary edema Subset II:
Typical Dosage/Administration
• Protect from light • Stable in D5W or NS in GLASS or special container • Special “nitro” tubing, avoid filters • Check for infusion incompatabilities • 5 to 10mcg/min initially • Titrate up to about 200mcg/min as continuous IV infusion
Need contractility and rate to maintain output
Biblioteka Baidu Autoregulation
• The ability to maintain blood flow over wide range of perfusion pressures • Cerebral and coronary arteries • Ability declines at MAP <60mmHg • Mediated by
It is important to relax!
• Remember that coronary arteries fill during diastole • Remember that filling during diastole contributes to stroke volume (Starling) • Remember that increasing heart rate decreases ventricular and coronary filling, upsets calcium processing by SR, O2 demand increase • Chronic HF patients have typically maxed out preload, and do not have the reserve that you do
Contractility
• Increased contractility will provide increased stroke volume/CO for a given level of preload and afterload • Chronic HF patients have high circulating levels of catecholamines and are less responsive to adrenergic stimuli
Loop diuretics
• Furosemide (Lasix)
– – – – – – – – – IV (40mg/5ml), IM, PO Bioavailability poor/variable Stable in LR, D5W or LR Typically 40mg – 80mg IVP over 1-2 min Repeat every 1-2 hours as needed Monitor hemodynamics Monitor I/O for measure of net fluid loss Administer potassium as needed in fluids Ototoxicity, allergy possible
– receptor downregulation
• Catecholamines cardiotoxic? Necrosis/apoptosis? Arrhythmias?
Afterload is double edged sword
• Increased SVR is important for maintaining MAP • Increased afterload will reduce stroke volume
Other Diuretics
Acute Heart Failure/ Cardiogenic Shock
April 16, 2004 Darren M. Triller, PharmD
The plan
• Stick close to the text • Review pharmacology and pathophysiology only to enhance understanding of the drug therapy • Know the few drugs well • Expectations for pharmacists in general hospital or home care practice • Test questions will target these goals
The Big Picture in Failure
Veins Preload
Heart
Arteries Afterload Need constriction to maintain pressure
Contractility
Need volume to increase stretch, Frank Starling
Why is this important?
• • • • HF common diagnosis Hospitalizations are common Associated costs are astronomical Pharmacists will routinely be involved in preparing and dispensing to ICU/CCU • Use of the drugs is frequently in urgent/emergent situations
– – – – ACEI BB Diuretics Dig
• Misc.: vaccines, smoking cessation, diet, education, etc…..
Approach by hemodynamic subset
Subset I: Subset II: perfusing, but with pulmonary edema