Question

In dogs, weighing 10 Kg BW, functional concentration of 30-40% oxygen can be achieved through an in venous catheter positioned transtracheally if the flow rate of oxygen is

• A. 1 - 2 L/min
• B. 3.5 L/min
• C. 6 - 7 L/min
• D. 10 L/min

Hint:

Oxygen Flow Rates for 10 kg Dog:
Transtracheal catheter $\rightarrow 1 - 2\text{ L/min}$ (Achieves $35-40\%\;\text{FiO}_2$).
Nasal prongs $\rightarrow 1-2\text{ L/min}$.
Oxygen Hood/Mask $\rightarrow 5-8\text{ L/min}$.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Transtracheal oxygen catheterization delivers 100% humidified oxygen directly into the tracheal bifurcation, achieving 30-40% $ ext{FiO}_2$ at low flow rates.
Key Formula or Approach:
\[ \text{Transtracheal Oxygen Flow Rate} = 50 - 100\text{ mL/kg/min} \implies 10\text{ kg} \times 100\text{ mL} = 1.0\text{ L/min} \approx 1 - 2\text{ L/min} \]

Step 2: Detailed Explanation:
In emergency veterinary critical care and oxygen therapy:
- Transtracheal Oxygen Insufflation: Delivers $100\%$ humidified oxygen directly through a percutaneous catheter into the distal trachea.
- Bypassing the anatomical dead space of the upper airways makes this route exceptionally efficient.
- For a $10\text{ kg}$ dog, a low flow rate of 1 to 2 L/min ($50 - 100\text{ mL/kg/min}$) is sufficient to achieve an effective fraction of inspired oxygen ($\text{FiO}_2$) of 30% to 40% without causing airway mucosal desiccation or barotrauma.

Step 3: Final Answer:
Thus, the required oxygen flow rate is 1 - 2 L/min, matching option (A).