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• Dr.Tugume Elias
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• 20 April, 2025

Importance of pre-oxygination in TIVA

IMPORTANCE OF PER-OXYGENATION IN TIVA.

Compiled by:Tugume Elias, Anesthesiologist, and a 2nd year Master`s Student of Clinical Pediatrics.

My interest to compile this article evolves from opposition I always find in the theater. One time I was actually opposed by another Anesthesiologist friend. So I decided to make this information brief and accessible to the medical community. Gone are the days, where Doctors concealed information to themselves. Let`s go:

Pre-oxygenation is crucial, maintaining oxygenation throughout the intraoperative period is also essential, particularly in Total Intravenous Anesthesia (TIVA). Here’s why maintaining intraoperative oxygenation could be safer:

1. Preoxygenation in TIVA:
• Preoxygenation is typically done before anesthesia induction to build up oxygen reserves in the lungs, especially since apnea occurs after muscle relaxation and during intubation.
• It helps prolong the time to desaturation (critical hypoxia) during intubation or when there is a brief period of apnea.
2. Intraoperative Oxygenation in TIVA:
• In TIVA, unlike inhalational anesthesia, there is no continuous administration of volatile anesthetics mixed with oxygen, so maintaining an adequate oxygen supply is crucial.
• During the intraoperative period, if oxygenation is not properly monitored or supported, hypoxia could still occur, especially in patients with pre-existing respiratory issues or compromised lung function.
• Continuous monitoring of oxygen saturation (SpO2) and arterial blood gases (if applicable) ensures that the patient is receiving adequate oxygen and helps detect any intraoperative hypoxia early.
3. Benefits of Continuous Oxygenation:
• Ensures adequate tissue oxygenation throughout surgery, reducing the risk of hypoxic injury, especially in prolonged procedures.
• In high-risk patients (obese, elderly, pregnant, or critically ill), maintaining oxygenation beyond the preoxygenation phase is vital to compensate for increased oxygen demands or decreased lung efficiency.
• Helps avoid complications like atelectasis or hypoxia, which can lead to poor outcomes if not managed intraoperatively.
4. Special Situations:
• Patients with difficult airways, respiratory conditions, or undergoing emergency procedures may require both preoxygenation and continuous oxygenation throughout the procedure to maintain safe oxygen levels.

NB: Note that, by the time oximeters starts indicating desaturation of oxygen, Hypoxia and Hypoxemia could be in more advanced stage undetected.

 Here’s how preoxygenation is usually conducted:

1. Preoxygenation with a Face Mask:

• Preferred Method: A tightly fitting face mask is usually preferred for preoxygenation because it ensures the delivery of the highest concentration of oxygen (close to 100% FiO2).
• Flow Rate: Oxygen is typically delivered at a high flow rate, usually 10-15 liters per minute (L/min), to ensure rapid washout of nitrogen from the lungs and maximum oxygen saturation.
• Duration: Standard preoxygenation is achieved either by:
• Tidal volume breathing for 3 minutes, where the patient breathes normally with 100% oxygen.
• Deep breaths (vital capacity breaths) for about 1 minute (e.g., 8 breaths in 1 minute), which can also be used to achieve rapid preoxygenation.

2. Preoxygenation with Nasal Prongs (Nasal Cannula):

• Apneic Oxygenation: Sometimes, nasal cannula can be used during procedures to deliver oxygen during periods of apnea (e.g., after induction of anesthesia and before intubation).
• Flow Rate: In apneic oxygenation, nasal prongs are typically set at a flow rate of 5-15 L/min, delivering supplemental oxygen while maintaining spontaneous breathing or when the patient is apneic.

When to Use a Face Mask vs. Nasal Prongs:

• Face Mask: Standard for most cases to ensure maximal preoxygenation, especially in patients at risk of rapid desaturation (e.g., obese, critically ill, pregnant patients).
• Nasal Prongs: Useful for apneic oxygenation or in cases where the patient cannot tolerate a face mask, but it provides a lower concentration of oxygen compared to a well-sealed face mask.

For effective preoxygenation, the face mask is generally the preferred tool, with high oxygen flow rates (10-15 L/min), ensuring that the patient’s lungs are fully saturated with oxygen before anesthesia induction. While preoxygenation is essential in preventing desaturation during the induction of anesthesia in TIVA, maintaining adequate oxygenation throughout the surgery is critical to ensuring patient safety, especially for those at higher risk of intraoperative hypoxia.

 This article was compiled by Tugume Elias;

Prof.Ms Anes.&Crit.Care, Adv.Ms Clin. Ped.