# 2023.1 Day 2 VIVA 8

A 37 year old woman is booked for a diagnostic laparoscopy and dye studies today for investigation of infertility. She has a weight of 95kg, BMI of 35, but otherwise no significant medical history or known allergies. She has not been seen in the pre-anaesthetic clinic.&#x20;

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<summary>How would you assess this patient’s airway when planning your anaesthetic?</summary>

**Obesity-related factors**:

* **Obstructive sleep apnoea (OSA)** is a key concern due to BMI of 35, which increases the risk of airway obstruction and difficult intubation. Consider a **modified Mallampati score**, assessing for any signs of **OSA**, such as snoring or daytime fatigue.
* **Assess neck circumference** and **thyromental distance**, as these can help predict airway difficulty in obese patients.

**Airway anatomy**:

* Perform a **mouth opening**, **mandibular protrusion** test to assess for potential difficult intubation.
* Ensure no visible dental issues or anatomical obstructions that could complicate airway management.

**Pneumoperitoneum considerations**:

* Anticipate **increased intra-abdominal pressure** from insufflation, which can **impede diaphragmatic movement** and limit lung compliance. Be prepared for **ventilation changes** during the procedure.

**Ventilation plan**:

* Consider using **rapid-sequence induction (RSI)** for induction to minimize aspiration risk.
* Prepare for **airway adjuncts** like an **oral or nasal airway** or **LMA** in case of difficulty maintaining ventilation.

**Positioning**:

* Position the patient **head-up** for **optimal respiratory mechanics**, and ensure the head and neck are in a **neutral position** to avoid airway obstruction.

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<summary>What specific considerations would you take for managing ventilation in this patient, particularly in the context of obesity?</summary>

* **Pre-oxygenation**: Use **high-flow oxygen** for **5 minutes** pre-induction to maximize oxygen reserves.
* **Obesity** reduces functional residual capacity and increases the risk of hypoxia. Position the patient to facilitate optimal ventilation—consider **head elevation** and ensure **adequate padding** to maintain the **neutral position of the neck**.
* **Ventilation**:
  * Be prepared for **reduced lung compliance** with increased intra-abdominal pressure due to **pneumoperitoneum**.
  * **Controlled ventilation** with **low tidal volumes** may be required. Consider **positive end-expiratory pressure (PEEP)** to support oxygenation during pneumoperitoneum.
  * Watch for **hypercapnia** (increased CO₂) and plan for **rapid ventilation adjustments** if CO₂ rise

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<summary>What would be your immediate actions if the CO₂ trace is lost after commencing surgery?</summary>

**Check the equipment**:

* **Ventilator circuit**: Ensure that there are no **kinks** or **disconnections** in the circuit.
* **Endotracheal tube (ETT)**: Confirm the **ETT placement** (check **capnography**, **chest rise**, and **auscultation** to verify correct positioning).
* Ensure that the **CO₂ detector** or **sensor** is functioning correctly.

**Patient assessment**:

* Check for **signs of ventilatory compromise** (e.g., **saturation drop**, **increased airway pressures**, or **end-tidal oxygen**).
* **Auscultate the chest** to detect signs of **airway obstruction** (e.g., bronchospasm, ETT displacement).

**Consider other causes**:

* **Pneumothorax**: Check for signs of tension pneumothorax (e.g., **unilateral chest expansion**, **hypotension**, **tachypnoea**).
* **Aspiration**: Look for signs of **aspiration** or **pulmonary oedema**.
* **Circulatory issues**: Check for **hypotension** or **cardiac arrest**, which may explain a loss of circulation-related CO₂.

**Temporary measures**:

* **Ventilate manually** to assess for **airway patency** or consider an **adjustment** in ventilation settings to correct the issue.
* If no resolution is found, consider **reintubating** or securing the airway with **alternative devices** (e.g., **LMA**).

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<summary>What criteria would you use to assess readiness for extubation?</summary>

* **Spontaneous breathing**: Confirm that the patient is **breathing spontaneously** with adequate tidal volumes and respiratory rate.
* **Adequate airway reflexes**: Check for **cough reflex** and **gag reflex** to ensure airway protection post-extubation.
* **Hemodynamic stability**: Ensure **stable blood pressure** and **heart rate** with no signs of shock or distress.
* **Saturation**: Verify that **oxygen saturation** is above **90%** on room air or appropriate oxygen supplementation.
* **Sedation levels**: The patient should be **adequately awake** and alert, able to follow commands.

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<summary>What would you do if the patient develops difficulty breathing or shows signs of airway obstruction in PACU?</summary>

**Assess the airway**:

* Check for signs of **airway obstruction** (e.g., **stridor**, **increased work of breathing**, **cyanosis**).
* Consider **airway positioning**: Adjust head position or try a **jaw thrust** to relieve any obstruction.

**Interventions**:

* Administer **100% oxygen** via a **non-rebreather mask**.
* If obstruction persists, consider inserting an **oral or nasopharyngeal airway** or **LMA**.
* **Suction** any secretions from the airway if they are contributing to obstruction.

- **If the patient is unresponsive or continues to deteriorate**, consider **bag-mask ventilation** and prepare for **intubation** if needed.
- **Sedation reversal**: If oversedation is suspected, administer appropriate **reversal agents** (e.g., **flumazenil** or **naloxone**, depending on the agent used).
- **Monitor**: Ensure the patient is **stable** before moving to a **lower level of care** or transferring to a general ward.

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<summary>What would be your plan for the patient’s post-operative disposition and handover?</summary>

**Post-operative monitoring**:

* Continue **close monitoring** of **respiratory status**, **oxygen saturation**, and **hemodynamics**.
* **Handover to nursing staff**: Provide a detailed handover, emphasizing any airway concerns, potential **respiratory depression**, and **sedation levels**.

**Special considerations**:

* Ensure that the patient’s **BMI** and potential for **OSA** are communicated to staff, with a focus on **airway management** and **respiratory monitoring**.

**Pain management**:

* Discuss a plan for **multimodal analgesia** (e.g., **opioids**, **paracetamol**, **NSAIDs**) for pain control, especially in the context of obesity, and **adjust opioid dosing** as needed for obesity-related drug sensitivities.

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