Oxygen AdministrationNasal Cannula
The nasal cannula is a thin tube with two small nozzles that protrude into the victim’s nostrils. It can only provide oxygen at low flow rates: 2-6 liters per minute, delivering a concentration of 28-44%. Use of the nasal cannula at higher flow rates than 6 liters per minute can cause discomfort by drying the nasal passages and pain from the force of the oxygen.
The task of administrating oxygen with bag-valve-mask (BVM) is not very demanding, and requires only one hand to squeeze the bag and one to maintain a good seal with the mask. Thus, this task can advantageously be achieved by one rescuer, who will then keep their mind free and, being at the head of the victim, have a good view of the overall situation. The head of the victim can be secured between the knees of the BVM operator. The bag-valve-mask (BVM) is used for victims in critical condition who require pure oxygen. A reservoir bag is attached to a central cylindrical bag, attached to a valved mask that administers 100% concentration oxygen at 8-15LPM. The central bag is squeezed manually to ventilate the victim.
The non-rebreathing mask (NRB) is utilized for patients with multiple trauma injuries, chronic airway limitation/chronic obstructive pulmonary diseases, smoke inhalation, and carbon monoxide poisoning, or any other patient that requires high-flow oxygen, but does not require breathing assistance. It has an attached reservoir bag where oxygen fills in between breaths, and a valve that largely prevents the inhalation of room or exhaled air. This allows the administration of high concentrations of oxygen, between 65-85%. This device is set to 10-15 lpm, or at least enough to keep the reservoir inflated between breaths. Due to the poor seal on a patient’s face, it is exceedingly difficult to obtain anything approaching 100% oxygen with this device. While some patients with Chronic Obstructive Pulmonary Disease (COPD) rely on what is called hypoxic drive, high flow oxygen should never be withheld from COPD patients who require it.
The pocket mask is a small device that can be carried on one’s person. It is used for the same victims that the BVM is indicated for, but instead of delivering breaths by squeezing a reservoir, the first aider must actually exhale into the mask. Pocket masks normally have one-way valves built into them to protect against cross-contamination. Many masks also have an oxygen intake built-in, allowing for administration of 50-60% oxygen.