CPAPRespiratory therapy EMT-B

CPAP Overview

Applies continuous pressure to airwaysto improve oxygenation. Bridge device to improve oxygenationuntil underlying cause of the respiratorydistress can be treated.

Primary Goal of CPAP

The primary goal of CPAP is to decrease the work of breathing so the patient doesn’t deteriorate, doesn’t require intubation—which is associated with increased mortality—and doesn’t suffer respiratory arrest.

C-PAP vs. PEEP

C-PAP non-invasive ? PEEP for intubatedpatients ? Terms usedinterchangeably

Control of Breathing

CO2 Level inArterial Blood ? Hypoxic Drive

Gas Exchange

Ventilation-allow oxygen to move from the air into the venous blood and carbon dioxide to move out.

Diffusion-Blood carries oxygen, carbon dioxide, and hydrogen ions between tissues and the lungs. The majority of CO2 transported in the blood is dissolved in plasma

Perfusion-blood flow through the pulmonary arterioles.

Ventilation

Diffusion

Perfusion

Congestive Heart Failure

The primary cause of respiratory distress with heart failure is increased work of breathing. In heart failure, the heart cannot efficiently pump the blood delivered to it.

Congestive Heart Failure

The role of CPAP in the treatment of heart failure is twofold

1. The PEEP helps keep the alveoli open during exhalation, and inspiratory pressure helps to open additional alveoli, relieving the work of breathing;2. The pressure generated by CPAP helps move fluid back into the vascular system.

Congestive Heart Failure

Pulmonary edemawashes out surfactant – Increased work of breathing tomaintain open alveoli

COPD

Chronic Obstructive Pulmonary Disease – Emphysema – Chronic Bronchitis – Asthma

Emphysema

Loss of elasticity oflung tissue – Difficulty exhaling • Air trapping • CO2 retention ? Break down of alveolar walls – Decrease surfacearea for gas exchange

Chronic Bronchitis

ChronicInflammation ofbronchiole tree withincreased mucousproduction ? Difficulty exhaling – Air trapping – CO2 retention

Asthma

IntermittentBronchoconstrictionDifficulty exhaling – Air trapping – CO2 retention

Physiological Benefits of C-PAP

Increase in alveolar pressure – Stop fluid movement into alveoli – Improves gas distribution – Prevents alveolar collapse – Improves re-expansion of alveoli Reduces work of breathing Reduces respiratory muscle fatigue

Physiological Benefits of C-PAP

Increases intrathoracic pressure – Improves cardiac output to a point – Too much PEEP decreases cardiac output Decreases need for intubation andassociated complications

Hazards/Complications of C-PAP

Airway – Mask impairs access to patient’s airway – C-PAP does not ventilate the patient – Gastric distension / vomiting • Aerophagia (swallowing air) sensitive patients – Gastric stapling – Upper GI surgery

Hazards/Complications of C-PAP

Hypoxia – Loss of oxygen supply • Empty oxygen tank • Disconnection of Oxy-PEEP from oxygensource – Mask Leak – Rebound hypoxia may be more severe than initial hypoxia

Hazards/Complications of C-PAP

Hypotension – Increased intrathoracic pressure causes • Decreased venous return • Decreased cardiac output – Increased pulmonary pressure causes Decreased blood flow through pulmonaryvessels • Decreased cardiac output

Hazards/Complications of C-PAP

Patient Discomfort – Requires patient cooperation to tolerate a tightly fitting mask • Sensation of smothering or claustrophobia – Use trial to introduce patient to device prior to securing head strap – Consider sedation for extreme anxiety with orders from Medical Control

Procedure

Prepare Patient – Position Stretcher at 45 degrees or higher – Inform patient of procedure

Procedure

Mask Application – Trial to introduce device • Explain patient will feel positive oxygen pressure – Hold mask gently on patient’s face ensuring good seal – Once patient accepts mask, secure mask with straps – Deflate mask as needed to get good seal

Procedure On-Going Care / Monitoring – Reassess at least every 5 minutes • Patient’s impression of difficulty breathing • Vital signs • Lung sounds • SpO2 – Observe for complications • Hypotension • Barotrauma • Worsening dyspnea

Procedure

If patient continues to have severedifficulty breathing after 5 minutes,consider increasing PEEP to 10 cm H2O – Systolic BP must be at least 90 mmHg – CAREFULLY watch for complications ofincreased PEEP

Discontinuing C-PAP

C-PAP usually is not discontinued in thefieldHigh PEEP level may require weaning Rebound hypoxia can be worse thaninitial hypoxia