550 likes | 947 Views
Congestive Heart Failure and Pulmonary Edema. Nestor Nestor, MD June 21, 2006. Goals and Outline. Pathophysiology of Congestive Heart Failure (CHF) Recognizing CHF and Pulmonary Edema (PE) Prehospital Treatment. 1. Pathophysiology. Terminology.
E N D
Congestive Heart Failureand Pulmonary Edema Nestor Nestor, MD June 21, 2006
Goals and Outline • Pathophysiology of Congestive Heart Failure (CHF) • Recognizing CHF and Pulmonary Edema (PE) • Prehospital Treatment
Terminology • Heart Failure: The inability of the heart to maintain an output adequate to maintain the metabolic demands of the body. • Pulmonary Edema: An abnormal accumulation of fluid in the lungs. • CHF with Acute Pulmonary Edema: Pulmonary Edema due to Heart Failure (Cardiogenic Pulmonary Edema)
The Heart is Two Pumps in Series O2 CO2 LA RV tissue
Like any pump: • The heart generates pressure to deliver blood to the body • Therefore it also must…
alveolus lymphatic capillary Fluid (and some cells) from stagnating blood leak out…
Three Pathophysiological Causes of Failure • Increased work load (HTN) • Myocardial Dysfunction (ASCVD) • Decreased Ventricular Filling (Valvular, cardiomyopathy, etc.)
RV LV Normal Heart
Heart Failure - Concepts • Cardiac Output (L/min) • Afterload (BP) • Primarily arterial and systolic function • Preload (volume) • Primarily a venous and diastolic function • Frank-Starling Length: Tension Ratio • Why preload effects output
CHF: A Vicious Cycle Low Output Increased Preload Increased Afterload Norepinephrine Increased Salt Vasoconstriction Renal Blood Flow Renin Angiotension I Angiotension II Aldosterone
Airway no gas exchange O2 CO2 flow Gas exchange
Micro-anatomy with fluid displacement Normal Micro-anatomy Infiltration of Interstitial Space
Perivascular cuffs in early pulmonary edema cuff Normal lung Early pulmonary edema
flow The ultimate insult: alveolar flooding
Precipitating Causes • Non-Compliance with Meds and Diet • Increased Sodium Diet (Holiday Failure) • Acute MI • Arrhythmia (e.g. AF) • Infection (pneumonia, viral illness) • Pregnancy
History, History, History • Acute or chronic onset • Prior episodes • Weight gain • Medications
Fatigue Nocturia DOE PND GI Symptoms Chest Pain Orthopnea Profound Dyspnea Symptoms
Vitals • Tachypnic • Tachycardic • Hypoxic • Hypertensive (even “normal” may be too high) • or Hypotensive in severe failure
Anxious Pale Clammy Confusion Edema Diaphoretic Rales Rhonchi S3 Gallop JVD Pink Frothy Sputum Cyanosis Physical Exam
EMS Management • Sit upright • High Flow O2 • Nitroglycerine (If SBP > 100) • Morphine • Diuretics (furosemide) • Ventilatory Support • CPAP • BVM • Intubation and ventilation
Pharmacological Treatment: Nitroglycerine (NTG) • Relaxes arteries and veins • 0.4 mg sub lingual or 1 spray • Repeat x2 every 5 min if SBP > 100 • Consider 1” NTG paste to CW
Pharmacological Treatment: Morphine • Also relaxes arteries and veins • Reduces anxiety and O2 demand • 2-4 mg IV
Pharmacological Treatment: Furosemide (Lasix) • A diuretic, reducing fluid overload • Requires good enough cardiac output to reach the kidneys • 40mg IV • May require more if already taking Lasix
Pharmacological Treatment: Beta Blockers (Lopressor)??? • Not useful in acute CHF • Decrease HR and output, worsening failure • May cause/worsen bronchoconstriction • However they are used in stable, compensated failure so they may be on a pt’s med list
Ventilatory Support: CPAP Continuous Positive Airway Pressure
CPAP is oxygen therapy in its most efficient form. • Simple Masks • Venturi Masks • CPAP
The Pressure Gradient Why does oxygen pass into the blood? Deoxygenated blood has a lower partial pressure of oxygen so oxygen transfers from the air into the blood.
CPAP and Patient Airway Pressure ‘The application of positive airway pressure throughout the whole respiratory cycle to spontaneously breathing patients.
CPAP increases the pressure gradient • 7.5cm H2O CPAP increases the partial pressure of the alveolar air by approximately 1%. • This increase in partial pressure ‘forces’ more oxygen into the blood. • Even this comparatively small change is enough to make a clinical difference.
Physiological Effects Of CPAP • Increases the volume of gas remaining in lungs at end-expiration • CPAP distends alveoli preventing collapse on expiration • Greater surface area improves gas exchange • Reduces work of breathing
CPAP And Pulmonary Edema • CPAP increases transpulmonary pressure • CPAP improves lung compliance • CPAP improves arterial blood oxygenation • CPAP redistributes extravascular lung water
CPAP And Acute Respiratory Failure • CPAP prevents airway collapse during exhalation • CPAP overcomes inspiratory work imposed by auto-peep (pursed lip breathing) • CPAP may avoid intubation and mechanical ventilation
Caution • COPD and Asthmatic patients do not respond predictably to CPAP • Higher risk of complications such as pneumothorax
When Not To Use Mask CPAP • Pneumothorax (evolve into tension) • Hypovolemia (further limit preload) • Severe facial injuries • Patients at risk of vomiting
Common Complications With CPAP • Gastric distension • Pulmonary barotrauma • Reduced cardiac output • Hypoventilation
CPAP Flow Sheet • No Exclusion Criteria Present • -Respiratory/Cardiac Arrest • Pt.unable to follow commands • Unable tp maintain patent airway independently • Major Trauma • Suspicion of a Pneumothorax • Vomiting or Active GI Bleed • Obvious signs/Symptoms of Pulmonary infection • 2 or more of the following Respiratory Distress • Inclusion Criteria • Retractions of accessory muscles • Brochospasm or Rales on Exam • Respiratory Rate > 25/min. • O2 Sat. < 92% on high flow O2 Administer CPAP using Max FIO2 Stable or Improving Reassess Patient Deteriorating • -Contact Medical Control with report • Discontinue CPAP unless advised by Medical Control • Continue Asthma/COPD/Pulmonary Edema Protocols • Continue CPAP • Continue COPD/Asthma/Pulmonary Edema Protocol • Contact Medical Control with a Report ,
Ventilatory Support: Intubation Definitive (but not first) treatment of pulmonary edema Positive pressure redistributes edema fluid as in CPAP but to a greater extent Mechanical ventilation greatly reduces O2 demand Sedation/paralysis also reduces O2 demand and increases compliance
Ultimate Therapies • If pt stabilizes: long term therapy with beta blockers and ACE inhibitors • If cardiac output remains unacceptable: • Beta agonists • LVAD • Transplant