1 / 29

CPAP (Continuous Positive Airway Pressure)

CPAP (Continuous Positive Airway Pressure). Cardiogenic Pulmonary Edema. Case Study. Call to residence @ 2146 76 y/o male, SOB On arrival: Pt. seated upright in living room Conscious, obvious resp. distress, agitated Pale, diaphoretic, clammy, audibly congested

heller
Télécharger la présentation

CPAP (Continuous Positive Airway Pressure)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CPAP(Continuous Positive Airway Pressure) Cardiogenic Pulmonary Edema

  2. Case Study • Call to residence @ 2146 • 76 y/o male, SOB • On arrival: • Pt. seated upright in living room • Conscious, obvious resp. distress, agitated • Pale, diaphoretic, clammy, audibly congested • Assessment/Questions/Initial Tx ?

  3. Case Study (cont’d) • Incident Hx; at rest, abrupt onset, now worse • PMHx; MI, CHF/Pulm. Edema, HPT, AAA repair, Renal Tumor, Rx • Presentation; sitting upright, tachypneic, 1-2 word dyspnea, ↓A/E bil. with coarse crackles throughout, now RSCP

  4. Case Study (cont’d) • Vitals; P 60, Irr, R 36-40, B/P 200/94, SpO2 76 RA, Skin-Pale/Dia. +++/Cool • Monitor; Sinus with PVC’s, 12-lead neg. • Any other questions/info req’d? • Tx?

  5. Case Study (cont’d) • O2 - Device, FiO2? • Position? Why? • Rx – Drug(s) of choice/availability/benefit • Directive • Goals of Tx?

  6. Case Study (cont’d) • Current options to improve oxygenation/ventilation? • NRB mask - benefits/limitations • BVM - benefits/limitations • ETT - benefits/limitations • Other options?

  7. Definitions • CHF - inability of heart to maintain forward circulation of blood. • Most severe manifestation; pulmonary edema • Pulmonary Edema - extravasation of fluid from pulmonary vasculature to interstitium/alveoli of lungs

  8. Pathophysiological Mechanisms • Imbalance of Starling forces • Damage to Alveolar/Capillary barrier • Lymphatic obstruction/dysfunction • Idiopathic

  9. Cardiogenic Pulmonary Edema • Normal fluid shift/removal: • Opposing forces of plasma oncotic pressure and pulmonary capillary hydrostatic pressure • Lymphatics remove excess • Abnormal: • Volume in pulmonary veins/left atrial venous return exceeds left ventricular output • ↑pulmonary venous pressure • ↑capillary hydrostatic pressure

  10. Pulmonary Edema (cont’d) • Pulmonary capillary pressure exceeds plasma colloidal osmotic pressure • (Norm. PCWP 8-12 mmHg, Normal Colloidal Osmotic Pressure 25-28 mmHg) • Fluid shifts to interstitium • Lymphatic removal does not increase in proportion to fluid accumulation

  11. Pulmonary Edema (cont’d) • Stages: • ↑Lt. atrial pressure opens/distends small pulmonary vessels • Fluid/colloids shift to interstitium • Continual filtration overwhelms lymphatics • Fluid accumulates/surround alveoli/bronchioles (compromises small airways first) • Increases space between capillaries/alveoli • Disrupts alveolar membrane-floods alveoli

  12. Pulmonary Edema (cont’d) • Effects: • Decreases vital capacity • Causes abnormalities in gas exchange • Decreases respiratory volume • Leads to hypoxemia

  13. Pulmonary Edema (cont’d) • Vicious cycle ensues: • ↓CO stimulates sympathetic activity • Renin-Angiotensin-Aldosterone system • Catecholamine production: • ↑ PVR • ↑ MVO2 • exacerbates myocardial ischemia • ↓ LV filling/emptying/function • Further ↑ pulmonary capillary hydrostatic pressure • More fluid shift

  14. Pulmonary Edema (cont’d) • Cardiac causes: • CAD • Loss of LV muscle/function • Valvular heart disease • Decreased diastolic ventricular compliance • Congenital heart disease • Myocarditis • Infectious endocarditis • ↑ B/P

  15. Pulmonary Edema (cont’d) • Precipitated by: • Ischemia • Dysrhythmia • Cardiac/extra cardiac infection • P.E. • Physical/environmental stress • Non-compliance/changes to Rx • Dietary changes • Iatrogenic volume overload • Pregnancy • Hyperthyroidism

  16. Differentials • ARDS • Anaphylaxis • Acute anemia • Bronchitis • COPD • Myopathies • Pneumonia • Pneumo • Shock (septic) • P.E.

  17. Treatment • ABC’s • Improve oxygenation/ventilation • O2 to keep SpO2 > 90% • Assist ventilations or provide non-invasive positive pressure ventilation • 3 Goals: • ↓ Preload • ↓ Afterload • Inotropic support

  18. Treatment (cont’d) • Preload reduction: • ↓’s pulmonary capillary hydrostatic pressure • ↓’s rate of fluid shift • Afterload reduction: • ↑’s CO • ↑’s Renal perfusion • Inotropic support: • For those that won’t tolerate preload/afterload reduction 2º to hypotension

  19. Nitroglycerin • Vasodilator • Used with normotensive/hypertensive patients • Most effective, predictable and rapid-acting Rx available for preload reduction • Often occurs within 5 min. • Usually with some afterload reduction as well

  20. Nitroglycerine (cont’d) • ↓’s MVO2 by ↓’ng workload • ↑’s coronary blood flow • ↑’s forward blood flow • ↓’s pulmonary hydrostatic pressure/pulmonary congestion • SL spray: • Onset 1-3 min. • Half-life 5 min.

  21. Furosemide (Peterborough Region Only) • Long-standing mainstay of therapy • Thought to have two physiological effects: • Immediate venodilation • Diuretic affect • May in fact be more harmful than beneficial • Move away from use in many prehospital services

  22. Morphine (Peterborough Region Only) • Third drug in “classic” treatment • Again, thought to have two major benefits: • Preload/Afterload reduction through vasodilation • Anxiolytic/Analgesic effects • No sound evidence supports morphine-mediated preload reduction • Recent studies show morphine use an independent predictor of mortality • Use has declined both in-hospital and prehospital

  23. Non-invasive Ventilation • Delivery of ventilatory support without need of invasive artificial airway • Will often eliminate the need for intubation/tracheostomy • Benefits: • Easier to wean off ventilator • Preserves normal cough/swallowing/speech mechanisms

  24. NPPV (cont’d) • Two methods: • BiPAP (Bilevel Positive Airway Pressure) • CPAP (Continuous Positive Airway Pressure)

  25. CPAP • Delivered by nasal or face mask • Pt. breathes through mask against a continuous positive a/w pressure • Can be delivered by either volume or pressure controlled ventilator • Delivers set pressure with each breath, maintained throughout the respiratory cycle

  26. CPAP (cont’d) • Mechanism: • Increases gas exchange 2º to increased alveolar ventilation • Prevents alveolar collapse during exhalation by maintaining a positive intra-alveolar pressure • ↑’s intrathoracic pressure, reducing preload/afterload and improving cardiac output

  27. CPAP (cont’d) • Benefits: • Reduces need for intubation • Pt. saves energy otherwise spent trying to reopen collapsed alveoli • ↓’ WOB: improves alveolar ventilation while simultaneously resting respiratory muscles • ↓’s metabolic rate/substrate need to fuel respiratory effort

  28. CPAP (cont’d) • Advantages: • Avoidance of intubation-related trauma • Decreased incidence of nosocomial pneumonia • Enhances pt. comfort • Shorter duration of ventilator use/facilitates weaning • Decreased hospital stay • Decreased costs

  29. CPAP (cont’d) • Usage: • Currently utilized primarily in-hospital setting and by critical care EMS systems • Also used in-home • Wide-scale EMS use previously limited by cost/complexity of technology • Newer technology and sig. reduced costs lend to increased use pre-hospital • Numerous systems incorporating CPAP as standard for pulmonary edema therapy

More Related