cpap final 2012_12 (2)
TRANSCRIPT
Continuous Positive Airway Pressure
For EMT Providers
State Education & Training CommitteeDecember 2012
Goal
The student will be able to correctly utilize service specific CPAP devices in a respiratory compromised patient
[img]http://hammondems.com/images/d_1976.jpg
Objectives
At the completion of this training, the BLS provider will: Describe respiratory anatomy and physiology Verbalize understanding of respiratory
disorders / illnesses Appreciate the benefits and limitations of
CPAP in alleviating patient symptoms List indication and contraindications for use.
Anatomy and Physiology of Respiration
Respiratory Physiology
Nose / Mouth Trachea Mainstem Bronchi Secondary Bronchi Tertiary Bronchi Bronchioles Terminal Bronchiole Alveoli Diaphragm
http://www.uni.edu/schneidj/webquests/spring04/offtowar/respiratory.html
InhalationInhalation
Active process Negative
pressure pulls air into lungs
continued
Exhalation
Passive process Muscles relax;
size of chest decreases
Positive pressure created; air pushed out
continued
Negative Pressure
Respiration driven by process of negative intrathoracic pressures Negative pressure
Initiates inhalation and acquires O2
Assists to increase intrathoracic blood flow
Equalization of pressures initiates exhalation and elimination of CO2
Bronchi / Bronchioles
Cartilage structures give way to smooth muscle
May divide up to 25 times before reaching terminal bronchioles
http//medicalpicturesinfo.com/bronchial-tree/
Alveoli
Expand and contract with breathing Contact with pulmonary capillary beds for gas
exchange Inside surface coated with surfactant
Prevents aveoli from sticking together Keeps alveoli open
Atelectasis
Mechanics of Respiration
http://www.teachpe.com/anatomy/respiratory_system.php
Functional Residual Capacity
Lung volume at end of normal exhalation
Muscles of respiration are completely relaxed
http://www.lakesidepress.com/pulmonary/htm
Gas Exchange
http://www.uic.edu/classes/bios/bios100/lectures/circ.htm
Oxygenation
Process of getting oxygen to end organs and tissues Inhaled through lungs Picked up from alveoli on RBCs Off-loaded in exchange for CO2
Measured by pulse oximetry (SpO2)94%-100%
Ventilation
Process to eliminate carbon dioxide (waste product of energy production) Carried back through venous blood Eliminated through exhalation
Measured by capnography
Respiratory Disorders
Respiratory Disorders
A combination of many disease processes responsible for emergencies related to
ventilation, diffusion and perfusion.
Respiratory Distress
Subjective indication of some degree of difficulty breathing Causes
Upper or lower airway obstruction Inadequate ventilation Impaired respiratory muscle function Impaired nervous system Trauma Bronchitis, pneumonia, cancer
Respiratory Failure
Clinical state of inadequate oxygenation, ventilation or both.
Often end-stage of respiratory distress Signs:
Tachypnea (early) Bradypnea or apnea (late) Increased, decreased, or no respiratory effort Tachycardia (early) Bradycardia (late) Cyanosis Altered Mental Status
Mechanism of Heart Failure
Frequently a chronic, yet manageable condition
Left ventricle fails to work as effective pump (Left-Sided CHF)
Blood volume backs up into pulmonary circulation
Most often caused by: Volume overload Pressure overload Loss of myocardial tissue
Pulmonary Edema
Cardiac and respiratory system impairment Acute and critical emergency Filling of lungs with fluid
Washes away surfactant Lipids & Proteins Prevents collapse of alveolus at low lung
volume Creates pink froth in sputum
Prevents alveoli from expanding Significantly reduces or eliminates ability for gas
exchange to occur
Asthma
Reactive airway disorder Exacerbation precipitated by extrinsic or
intrinsic factors Characterized by reversible bronchial smooth
muscle contraction, increased mucus production and inflammatory airway changes
Persistent signs and symptoms can indicate a tenfold increase in the work of breathing
Asthma
Evolution of asthma attack Mucus thickens and
accumulates plugging airways
Mucosal edema develops
Muscle spasms constrict small airways
Breathing becomes labored
http://asthma-ppt.com/asthma-pictures.html
Caution
Asthma Anaphylaxis
Causes Smoke, dander, dust, pollen, cold air, mold, cleaning products, perfume, exercise
Nuts, shellfish, milk, eggs, soy, wheat, insect stings, medications, latex
Symptoms WheezingCoughingShortness of breathDifficulty breathingChest tightness
Face - itchiness, redness, swelling of face & tongueAirway – trouble breathing, swallowing or speakingStomach – abdominal pain, vomiting, diarrheaTotal hives, rash, itchiness, swelling, weakness, pallor, sense of doom, loss of consciousness
Chronic Obstructive Pulmonary Disease
Obstructive lung disease Triad of distinct diseases that often coexist
Asthma Chronic bronchitis Emphysema
Traditionally refers to patients with combination of chronic bronchitis and emphysema
Chronic Bronchitis
Bronchi become filled with excessive mucus Alveoli are not affected Diffusion of gas remains relatively normal
Patients develop low oxygen pressures (PO2) and hypoventilation
Hypoventilation leads to high levels of CO2
and low levels of O2
Emphysema
Results from pathological changes in the lung Permanent abnormal
enlargement of air spaces beyond terminal bronchioles
Collapse of the bronchioles
Destruction of the alveoli
http://health.allrefer.com/health/chronic-obstructive-pulmonary-disease-emphysema.html
Emphysema
Patients have some resistance to airflow, primarily on exhalation Hyper-expansion
caused by air trapped in the alveoli
Breathing becomes an active process
Sanders, M.J. (2005) Paramedic Textbook (3rd ed.) St. Louis: Mosby-Elsevier
Emphysema
Risk of pneumothorax Interior airway pressure
CO2 Retention Potential worsening with CPAP
ContinuousPositiveAirway
Pressure
The use of CPAP prehospitally reduces the need for intubation by 30% and reduces mortality by 20%
Annals of Emergency Medicine, September 2008
CPAP
Non-invasive ventilation
Continuous O2
delivered at a set positive pressure throughout the respiratory cycle
www.ems1.com/cpap-for-ems
Positive Pressure
PUSHES air into the chest Overcomes airway resistance
Bag valve mask Demand valve Intubation / mechanical ventilation CPAP
Effects of CPAP
Increases functional residual capacity
Increases alveolar surface area available for gas exchange
Increases oxygen diffusion across alveolar membranes
Reduced work of breathing
Indications
Severe Respiratory Distress / Respiratory Failure Accessory muscle use? Persistent hypoxia despite appropriate /
aggressive oxygen therapy? Marked increased work of breathing? Inability to speak full sentences?
Differentiate Pulmonary Edema versus other Respiratory Disorder
Contraindications
Respiratory rate < 10 breaths / minute Systolic blood pressure < 100 mmHg Confusion
Inability to understand directions and cooperate with application of CPAP
History of pneumothorax History of recent tracheo-bronchial surgery
Active nausea or vomiting Unconscious Facial Injuries
How CPAP Works
Maintains constant level of airway pressure
Keeps and maintains alveoli open.
Moves fluid into vasculature (pulmonary edema)
Improves gas exchange
Buys time for medications to work
PEEP & Fi02
Positive End-Expiratory Pressure The purpose of PEEP is to increase the volume of gas
remaining in the lungs at the end of expiration in order to decrease the shunting of blood through the lungs and improve gas exchange.
Fraction of inspired oxygen The fraction or percentage of oxygen in the space being
measured. Natural air includes 20.9% oxygen, which is equivalent to
FiO2 of 0.21. Each additional liter of oxygen adds about 4% to their FiO2
Peep
Procedure
Prepare C-PAP Equipment – Adjust FiO2 to 95% – Set PEEP at 5 cm H2O – Set O2 flow at (minimum 15 LPM) – Ensure adequate supply of oxygen (main and portable) Reassess patient every 5 minutes
If patient continues to have severedifficulty breathing after 5 minutes,
consider increasing PEEP to 10 cm
H2O
Limitations
CPAP is not a mechanical ventilator
Tight mask seal can create claustrophobic response Consider allowing patient to self-seal (hold
own mask) until initial benefits recognized
CPAP is powered by on-board oxygen supply
Oxygen Utilization
Cylinder Flow
1000 PSI 1500 PSI 2000 PSI
D-15 LPM 8.5 min 13.8 min 19.2 min
D- 25 LPM 5.1 min 8.3 min 11.5 min
E- 15 LPM 14.9 min 24.3 min 33.6 min
E- 25 LPM 9 min 14.6 min 20.2 min
Cylinder Flow
500 PSI 1000 PSI 1500 PSI
M- 15 LPM 31 min 83 min 135 min
M- 25 LPM 18 min 50 min 81 min
G- 15 LPM 48 min 129 min 209 min
G- 25 LPM 29 min 77 min 125 min
Summary
Pre-hospital studies have proven the effectiveness of CPAP in treating patients with severe respiratory distress, regardless of disease process.
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