Views:0 Author:Site Editor Publish Time: 2021-01-05 Origin:Site
Today, patients can choose from a variety of oxygen masks, such as non-breathing oxygen mask, rebreathing oxygen mask. The choice of oxygen mask depends on the patient's oxygen needs, the equipment's efficacy, reliability, and the ease and acceptability of therapeutic application. Although design plays an important role in the selection of these devices, clinical evaluation and performance ultimately determine how and which devices should be selected.
According to the design of oxygen mask, there are usually three basic styles: low flow, storage tank, and high flow. With regard to the oxygen uptake fraction (FiO2) range, oxygen systems can be classified as hypoxic (<35%), medium (35%-60%), or high (>60%) as shown in the system. Some oxygen masks can provide a wide range of oxygen percentages. Now, we will review the different oxygen delivery masks, clinical indications, and use as follow:
Nasal catheters oxygen mask
Simple oxygen mask or non-breathing oxygen mask
Venturi oxygen mask or aerosol oxygen mask
The low-flow oxygen delivery system consists of a nasal cannula, a nasal catheter, and a tracheal catheter. They are designed to provide supplemental oxygen, which is usually less than the patient's total minutes of ventilation. Because the patient's tiny ventilation exceeds the flow rate, the oxygen delivered by the device will be diluted by ambient air, so less oxygen will be inhaled than expected.
A standard nasal cannula provides 24-44% of FiO2 at a supply rate of 1-8 liters (LPM) per minute. The formula is FiO2 = 20% + (4×oxygen liter flow rate). FiO2 is influenced by respiratory rate, tidal volume, and pathophysiology. The slower the inspiratory flow, the higher FiO2; The faster the suction rate, the lower the FiO2.A nasal cannula is not recommended for acute severe hypoxemia as the percentage of oxygen delivered is very inconsistent. The patient's upper respiratory tract ACTS as an oxygen reservoir for the nasal catheter. For flows greater than 4 LPM, humidification devices are recommended to ensure that dry inhaled gases are humidified. Nasal cannulation is best suited for patients with relatively stable respiratory patterns who require low oxygen percentages or who require supplemental oxygen during surgery or diagnosis or for home care.
The air storage system collects and stores oxygen during inhalation and exhalation. Patients can pump gas out of the reservoir at any time when their micro-ventilatory flow exceeds the device's delivery flow. Oxygen mask storage is usually used to increase the oxygen concentration delivered. Oxygen masks can be anywhere from 100 to 300 cm3 in volume, depending on size. It provides 40-60% FiO2 at 5-10 liters. FiO2 is affected by respiratory rate, tidal volume, and pathology. Oxygen masks are also a good choice for patients with nasal irritation or nasal EPI or strict breathing. Due to the low humidity of delivery and the drying effect of oxygen, a simple oxygen mask should only be used for a few hours. This device is best suited for a short-term emergency, surgical procedures.
When you need to FiO2 & get; For 40% and acute desaturation, a non-breathing oxygen mask should be used. It can provide up to 90% FiO2 when the flow setting is greater than 10 liters. For patients requiring accurate and high oxygen percentages, the device should be used for less than four hours due to insufficient humidity delivery and variable FiO2.
A high-flow oxygen delivery system provides a given oxygen concentration at a rate equal to or greater than the patient's inspiratory flow requirement. Accurate FiO2 delivery can be achieved if the delivery flow exceeds the patient's total flow.
When venturi oxygen masks mix oxygen with indoor air, they can produce a high flow rate of oxygen enrichment at the desired concentration. Venturi hoods are commonly used when clinicians are concerned about the retention of CO2 or inconsistency in respiratory drive. It is commonly used in patients with COPD who are concerned about the risk of knocking out a patient's hypoxia driver.