Problem 5 - Clinical Nursing Skills and Techniques

Question

A patient needs an FiO \(_{2}\) of \(80 \%\). Which of these oxygen delivery devices can deliver oxygen at this \(\mathrm{FiO}_{2}\) level? (Select all that apply.) 1 Nasal cannula at \(6 \mathrm{~L} / \mathrm{min}\) 2 Venturi mask at \(12 \mathrm{~L} / \mathrm{min}\) 3 Nonrebreathing mask at \(6 \mathrm{~L} / \mathrm{min}\) 4 Partial rebreathing mask at \(6 \mathrm{~L} / \mathrm{min}\)

Step-by-Step Solution

Answer

Only the nonrebreathing mask can potentially deliver 80% FiO2 at 6 L/min.

Step 1: Understanding FiO2

The fraction of inspired oxygen (FiO _{2}) measures the percentage of oxygen a person is inhaling. Room air has an FiO _{2} of about 21%. Supplemental oxygen delivery devices can increase this percentage to support patients with respiratory issues.

Step 2: Nasal Cannula and FiO2

A nasal cannula can typically deliver an FiO _{2} of 24% to 40% at a flow rate of 1 to 6 L/min. Therefore, it cannot achieve an FiO _{2} of 80% whether at 6 L/min or any other standard flow rate.

Step 3: Venturi Mask and FiO2

The venturi mask is capable of delivering precise FiO _{2} levels, ranging from 24% to 60%, depending on the selected oxygen entrainment port. At 12 L/min, it cannot reach an 80% delivery as it typically tops out around 60%.

Step 4: Nonrebreathing Mask and FiO2

A nonrebreathing mask can deliver FiO _{2} levels of 60% to 100%, depending on the flow, often used to achieve high inspiratory oxygen concentrations. At 6 L/min, it can deliver a high FiO _{2}, potentially meeting or exceeding 80%.

Step 5: Partial Rebreathing Mask and FiO2

A partial rebreathing mask can deliver approximately 40% to 70% FiO _{2}, depending on the fit of the mask and the patient's breathing pattern. It generally cannot achieve an 80% FiO _{2} at a flow of 6 L/min.

Key Concepts

FiO2 in Respiratory Care

FiO2, or the fraction of inspired oxygen, is a vital parameter in respiratory care. It represents the percentage of oxygen in the air mixture that a patient inhales. In a typical environment, room air consists of approximately 21% oxygen.

In clinical settings, various oxygen delivery devices are used to increase the FiO2 to support patients with respiratory difficulties. The goal is to ensure patients receive adequate oxygen to meet their physiological needs, potentially improving oxygenation status and relieving symptoms of hypoxia.

• FiO2 is crucial for optimizing a patient's oxygen levels, particularly during respiratory distress or insufficiency.
• Monitoring FiO2 helps healthcare professionals determine the appropriate oxygen therapy required for each patient.

Understanding the capabilities and limits of different oxygen delivery devices helps in selecting the right tool for the required FiO2.

Nasal Cannula

The nasal cannula is one of the most commonly used oxygen delivery devices in clinical settings. It is a lightweight, flexible tube with two small prongs that fit into the nostrils, providing a comfortable option for prolonged oxygen therapy.

Typically, a nasal cannula can deliver an FiO2 ranging from 24% to 40%, depending on the oxygen flow rate. It is designed for low to moderate oxygen requirements.

• Flow rates typically range from 1 to 6 liters per minute (L/min).
• The comfort and convenience of nasal cannulas make them suitable for both hospital and home use.

However, it’s important to note that the nasal cannula cannot achieve high FiO2 levels, such as 80%, regardless of the flow rate used. This limitation requires healthcare providers to consider alternative devices for higher oxygen needs.

Venturi Mask

A Venturi mask is a specialized oxygen delivery device designed to deliver precise FiO2 concentrations. It works by mixing oxygen with room air, allowing control over the percentage of oxygen delivered.

The Venturi mask is often used when accurate control of oxygen levels is necessary, especially for patients with chronic respiratory conditions.

• FiO2 levels can range from 24% to 60%, depending on the size of the color-coded entrainment ports.
• The flow rate and colored ports are set based on the prescribed oxygen concentration needed.

While highly effective in delivering controlled oxygen levels, the Venturi mask typically cannot attain an FiO2 as high as 80%, even at increased flow rates.

Nonrebreathing Mask

The nonrebreathing mask is utilized for delivering high concentrations of oxygen. It includes a reservoir bag and one-way valves which prevent the re-inhalation of exhaled air, thereby increasing the FiO2 delivered to the patient.

This design allows the mask to achieve FiO2 levels ranging from 60% to nearly 100%, depending on the oxygen flow rate set.

• Nonrebreathing masks are suitable for emergencies and situations requiring high oxygen delivery.
• The mask must fit snugly on the patient's face to prevent any ambient air from diluting the oxygen concentration.

At flow rates of 6 L/min, a nonrebreathing mask can potentially provide an FiO2 of over 80%, making it an appropriate choice for high oxygen needs in acute care settings.