Overview of Oxygen Therapy Devices

Oxygen Therapy Devices: An Overview

• Trainee doctors and nurses often lack knowledge regarding oxygen therapy devices and their appropriate usage.
• Misconceptions about oxygen therapy can lead to incorrect patient treatment on general wards.
• The video aims to cover the main types of oxygen delivery devices, enabling clinicians to adhere to guidelines by organizations like the British Thoracic Society and the American Association for Respiratory Care.
• The devices are categorized based on whether they supply a proportion of or the patient's entire ventilatory requirement.

Variable Oxygen Concentration Devices (Low Flow)

• Delivers oxygen at a flow rate lower than the patient's inspiratory needs, supplementing with room air.

Nasal Cannula

• A common method for oxygen therapy, featuring soft prongs connected to oxygen supply tubing.
• Tubing connects to the oxygen flow meter, with flow rate adjusted as needed.
• Prongs are inserted into the patient's nostrils, and the tubing is secured over the ears with a toggle.
• Flows of 6 liters per minute or less do not typically require humidification.
• Patients can eat, drink, and speak while using this device so long as no upper airway obstruction.
• Contraindicated for patients with nasal obstruction, such as nasal polyps.
• Oxygen flows of 1 to 6 liters per minute deliver up to 44% oxygen to most adult patients.
• Available in various adult, pediatric, and neonatal sizes, with different prong shapes.
  • Straight prongs: The original and most frequently used design.
  • Curved prongs: Direct oxygen flow posteriorly, away from the frontal sinuses.
  • Flared prongs: Have a wider diameter at the tip, slowing down gas entry for patient comfort.
  • Curved and flared prongs: Release oxygen slowly and away from the frontal sinuses, combining the previous benefits.
• Ear guards can be supplied to prevent sores for long-term nasal cannula users.
• Sentry nasal cannulas can sample exhaled carbon dioxide in non-intubated patients.
  • Suitable for patients under conscious sedation requiring respiratory depression monitoring.
  • A monitoring line connects the cannula to a capnograph.

Medium Concentration Oxygen Masks

• Offer an alternative for delivering low-flow oxygen therapy.
• Used when concentrations higher than nasal cannula are needed, or when the nostrils are unavailable.
• Available in adult and pediatric sizes.
• Red arrows illustrate oxygen delivered to the mask, which then can be drawn in by the patient.
• Orange arrows demonstrate ambient air being drawn in through the mask vents as the patient inhales.
• Blue arrows represent exhalation.
• A flow rate of 5 to 8 liters per minute delivers between 35% and 50% oxygen to most adult patients.
• Flow rates should be at least 5 liters per minute to wash out carbon dioxide from the mask.
• Aspiration of vomitus is more likely with these masks.
• Sentry masks are available, which enables capnography for end tidal CO2

High Concentration Masks (Non-Rebreathing Masks)

• Used when high oxygen concentrations are necessary, for example with critically ill patients.
• Patients breathe from the mask, with the inspiratory valve opening to draw oxygen from the reservoir bag.
• Expiratory valve releases what is breathed out.
• Older masks may not fit as well, with improved mask fit delivering close to 90% oxygen with flows of 10 to 15 liters per minute.
• Safety valves are included to allow air entry if the oxygen supply fails and the reservoir bag empties.
• The reservoir bag should deflate by no more than one-third at the end of inspiration.
• Aspiration of vomitus is more likely when a mask is in place.
• Recipe check breathing indicator displays respiratory rate using a ball in a clear tube.

Fixed Oxygen Concentration Devices (High Flow)

• Provides sufficient gas flow to meet all the patient's minute ventilation needs.
• Useful for patients with chronic lung disease and CO2 retention, reliant on hypoxic drive.
• Inspired oxygen concentration depends on the device design, not the patient's breathing pattern.
• Venturi devices accurately deliver predetermined oxygen concentrations that flows efficiently.
• Oxygen concentration does not vary with oxygen flow rate.
• Fixed venturi valves incorporated into oxygen recovery t-piece kits can provide supplementary oxygen to spontaneously breathing intubated patients
• Adjustable venturi valves offer a wide range of concentrations without valve replacement.
  • The Celente adjustable venturi valve can be set to concentrations between 26% and and 50%.
  • It has a twist lock mechanism to prevent inadvertent concentration changes.

Humidifiers

• Deliver cool humidification to administer sterile fluids.
• Two types of humidifiers:
  • Bubble humidifiers: Gas passes through the water to gain humidity as it rises to the surface.
  • Humidifier nebulizers: Venturi principle creates aerosol of small droplets by the oxygen stream.
• Bubble humidifiers add molecular water to gas.
• Humidifier nebulizers produces an aerosol or suspension of particles in gas
• Bubble humidifiers most commonly used with low-flow devices.
• Some bubble humidifier models have a pressure relief valve to prevent excessive pressures.
• Humidifier nebulizers use the venturi principle to create a low-pressure area at the end of a tube in a bottle containing sterile water.
• Humidifier nebulizers are most commonly used with devices such as aerosol and tracheostomy masks.
• Should conform to the international standards to to ensure that the oxygen concentrations are delivered accurately
• Aqua mist has a tamper proof control to prevent inadvertent changes to oxygen concentrations.
• Should be filled with sterile fluids that have changed every day any residual fluid should be drained from the bottle.
• DI SS oxygen connection is the most common type flow meter.

This lesson provides an overview of oxygen therapy devices. It covers the main types of oxygen delivery devices, including nasal cannulas and other variable oxygen concentration devices. The lesson is designed to help clinicians adhere to guidelines by organizations like the British Thoracic Society and the American Association for Respiratory Care.