# 2024.2 Day 1 VIVA 11

A 25-year-old female presents to Scenarioville with ultrasound-confirmed perforated appendicitis.&#x20;

She has a temperature of 38.5°C, a heart rate of 110 bpm, blood pressure of 95/55 mmHg, and pain rated at 7/10.&#x20;

She has a viable 28-week intrauterine pregnancy, has had an uneventful antenatal course and has no past medical history. Her BMI is 30.&#x20;

Specialists at a tertiary hospital recommend an emergency laparoscopic appendectomy at Scenarioville, with additional staff and retrieval services on standby for potential neonatal emergencies.

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<summary>Outline your pre-operative assessment and optimisation.</summary>

**Immediate Resuscitation**:

* IV access x2 (14G), bloods (FBC, UEC, LFTs, lactate, VBG)
* Fluid bolus (500ml crystalloid) → target urine output >0.5ml/kg/hr
* IV paracetamol + limited opioids (e.g., fentanyl 50mcg) for pain

**Airway Assessment**:

* Mallampati, thyromental distance - anticipate difficult intubation (BMI 30 + pregnancy)
* Prepare videolaryngoscope + difficult airway trolley

**Fetal Considerations**:

* Obstetric consult for CTG monitoring
* Avoid aortocaval compression - left uterine displacement

**Medication Safety**:

* Antibiotics: Ceftriaxone + metronidazole (TGA Category B1/B2)
* Avoid NSAIDs (risk of premature ductus arteriosus closure)

**Consent Discussion**:

* Risks: Premature labour (5-10%), fetal loss (1-2%), aspiration
* Benefits: Source control outweighs risks

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<summary><strong>Walk me through your antibiotic selection process for this patient.</strong></summary>

* Ceftriaxone (Category B1) and metronidazole (Category B2) as first-line for perforated appendicitis in pregnancy. These cover typical gut flora while having the safest fetal profiles.
* Avoid aminoglycosides unless absolutely necessary due to potential ototoxicity (Category D). The choice balances maternal sepsis management with fetal safety.
* Dosing would be weight-based, with renal adjustment if needed, and timed to achieve optimal tissue levels before incision.

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<summary><strong>How would you modify your approach if the patient had a known difficult airway?</strong></summary>

* Perform an awake videolaryngoscopy-assisted intubation with topical airway anesthesia
* Have a second experienced anaesthetist present
* Prepare a surgical airway kit and ensure the obstetric team is ready for emergency fetal delivery if prolonged hypoxia occurs
* Use lower dose induction agents to maintain spontaneous ventilation until airway secured

- The key is maintaining oxygenation while minimizing fetal compromise.

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<summary><strong>Discuss your fluid management strategy in detail.</strong></summary>

Restore perfusion without causing pulmonary edema, which is particularly risky in pregnancy.

* Start with a 500ml crystalloid bolus, reassessing response
* Target a urine output >0.5ml/kg/hr but avoid over-resuscitation
* Use balanced crystalloids rather than normal saline to avoid hyperchloremic acidosis
* Consider early arterial line for beat-to-beat monitoring if persistent hypotension
* Have vasopressors prepared (phenylephrine infusion) for refractory hypotension

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<summary><strong>How would you adjust your plan if this was a 16-week pregnancy?</strong></summary>

The principles of maternal resuscitation and source control remain paramount.

* Less concern about aortocaval compression - may not need left tilt until after 20 weeks
* Lower fetal risk from medications, but still avoid known teratogens
* Surgical approach might be more challenging due to uterine size
* Fetal monitoring would be less crucial as viability is lower

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<summary>Describe your anaesthetic plan for laparoscopic appendectomy.</summary>

* **Induction**:
  * RSI: Thiopentone 4-5mg/kg + suxamethonium 1.5mg/kg
  * Cricoid pressure until tube placement confirmed
  * Avoid propofol >2mg/kg (risk of maternal hypotension)
* **Ventilation**:
  * Target EtCO2 32-35 mmHg (mimic normal pregnancy)
  * Peak pressures <30 cmH2O - reduce insufflation pressure if needed
* **Haemodynamics**:
  * Phenylephrine infusion (50-100mcg/min) to maintain MAP >65mmHg
  * Limit IV fluids (risk of pulmonary edema)
* **Surgical Coordination**:
  * Open (Hasson) technique for pneumoperitoneum
  * CO2 insufflation <12mmHg

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<summary><strong>Detail your management if the patient becomes hypotensive during pneumoperitoneum.</strong></summary>

Resuscitation takes priority over diagnosis, however echo and arterial line monitoring should be considered in turn.

* First reduce insufflation pressure to ≤10mmHg
* Increase phenylephrine infusion rate
* Give a small fluid bolus (100-200ml) if likely hypovolemic
* Check for signs of venous gas embolism (mill-wheel murmur, sudden EtCO2 drop)
* Consider temporary Trendelenburg position if embolism suspected

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<summary>How would you modify ventilation for this obese pregnant patient?</summary>

The balance is between minimisation of volutrauma with maximisation of oxygenation.&#x20;

* Use lung-protective ventilation (6-8ml/kg ideal body weight)
* Apply PEEP 5-8cmH2O to prevent atelectasis
* Maintain slight respiratory alkalosis (PaCO2 28-32mmHg) to compensate for fetal acidosis
* Perform regular recruitment maneuvers
* Monitor airway pressures closely to avoid barotrauma

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<summary>What would you do if you couldn't achieve adequate surgical exposure with 12mmHg insufflation?</summary>

* First discuss with the surgeon whether they can proceed at lower pressure
* Consider brief increases to 14-15mmHg only when absolutely necessary for critical steps
* Compensate by increasing phenylephrine to maintain perfusion
* Monitor fetal heart rate closely during periods of higher pressure
* Consider converting to open procedure if exposure remains inadequate

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<summary>Describe your approach if the patient develops bronchospasm during the case.</summary>

In the event of life-threatening bronchospasm, I'd prepare for emergency delivery to improve maternal ventilation.

* First deepen anaesthesia with volatile agent
* Give salbutamol via ETT adapter
* Consider IV magnesium (2g over 20 minutes) for refractory cases
* Rule out mechanical causes (ETT malposition, pneumothorax)
* Monitor fetal heart rate closely as hypoxia affects the fetus first

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<summary>Outline your post-op management plan at Scenarioville.</summary>

* **Monitoring**:
  * HDU for 24hrs - hourly vitals, continuous CTG if >26 weeks
  * Fetal assessment: Daily growth scans if prolonged admission
* **Analgesia**:
  * Paracetamol 1g q6h + tramadol 50mg q6h (Category C but low-risk)
  * Avoid morphine PCA (risk of neonatal respiratory depression)
* **Complications Surveillance**:
  * Preterm labour: Tocolytic (nifedipine) if contractions
  * Sepsis: Repeat cultures, adjust antibiotics
* **Retriage Planning**:
  * Coordinate with retrieval team for neonatal ICU transfer if delivery imminent

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<summary>Detail your postoperative analgesia regimen and alternatives.</summary>

It is critical to avoid NSAIDs completely in third trimester.  Therefore:

* First-line:
  * Regular paracetamol 1g q6h2. Tramadol 50mg q6h PRN (maximum 400mg/day)
  * Consider transversus abdominis plane (TAP) block if expertise available
* Second Line:
  * Low-dose ketamine infusion (0.1mg/kg/hr)
  * Fentanyl PCA (lower fetal risk than morphine)

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<summary>How would you manage new-onset preterm labor postoperatively?</summary>

* Consult obstetrics
* Start tocolysis with nifedipine (first-line in sepsis as it doesn't cause pulmonary edema)
* Give betamethasone for fetal lung maturation if <34 weeks
* Optimize maternal oxygenation and perfusion
* Prepare for possible emergency delivery

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<summary>What monitoring would you insist on if HDU beds aren't available?</summary>

Minimum requirements would be:

* 1:1 nursing in recovery for first 4 hours
* Hourly vitals including SpO2
* Continuous CTG if >26 weeks
* Strict fluid balance monitoring
* Emergency call system for rapid response to deterioration

Document the suboptimal situation but accept it's the best available.

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<summary>How would you modify care if the retrieval team is delayed?</summary>

**Maternal Stabilization**

* Ensure airway patency and adequate oxygenation (SpO₂ >95%) with supplemental O₂ via non-rebreather mask
* Maintain systolic BP >100 mmHg using crystalloid boluses (250-500ml) and phenylephrine infusion if needed
* Continuous ECG monitoring for arrhythmias secondary to sepsis or electrolyte imbalances

**Fetal Protection**

* Administer betamethasone 12mg IM immediately if delivery appears imminent (<48 hours)
* Position in full left lateral tilt to optimize uteroplacental perfusion
* Continuous CTG monitoring with obstetric review q2h for signs of fetal compromise

**Neonatal Preparedness**

* Set up resuscitation area with:
  * Pre-warmed radiant warmer and dry towels
  * Neopuff T-piece resuscitator with 100% O₂
  * Umbilical catheterization kit for emergency vascular access
* Prepare medications:
  * Adrenaline 1:10,000 dilution
  * 10% glucose for potential neonatal hypoglycemia

**Resource Optimization**

* Mobilise all available staff:
  * Assign most experienced clinician to neonatal resuscitation
  * Utilise anesthetic nurses for maternal monitoring
* Improvised equipment:
  * Use syringe pumps for precise medication administration if infusion pumps unavailable
  * Consider manual ventilation with Mapleson C circuit if mechanical ventilator needed

**Communication Strategy**

* Designate a team leader to coordinate care
* Establish hourly updates with retrieval team regarding ETA
* Document all interventions thoroughly for handover

The key principles are:

* Maternal physiology takes precedence - a stable mother gives the fetus the best chance

**If delivery becomes unavoidable, I would prioritise:**

1. Neonatal thermoregulation (dry, warm, wrap in plastic)
2. Ventilation support (5 inflation breaths followed by 30-60/min if apneic)
3. Chest compressions if HR remains <60 bpm after 30s of effective ventilation

**Rationale for Key Decisions**:

* Betamethasone is prioritized as it takes 24h for full effect on fetal lung maturation
* Left lateral position improves uterine perfusion by \~30% compared to supine
* T-piece resuscitator is preferred over self-inflating bags for preterm neonates

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#### **6 Key Learning Points**

1. **Maternal Stability is Paramount**
   * Fetal outcomes depend on maternal physiology – always prioritise ABC (Airway, Breathing, Circulation) before fetal interventions.
2. **TGA Pregnancy Categories Guide Medication Safety**
   * Use Category B antibiotics (e.g., ceftriaxone) and avoid teratogens (e.g., NSAIDs in 3rd trimester).
3. **Pneumoperitoneum Pressures Affect Fetal Wellbeing**
   * Limit CO₂ insufflation to ≤12 mmHg to reduce fetal acidosis risk.
4. **Neuraxial Contraindications in Thrombocytopenia**
   * Platelets <75 × 10⁹/L = avoid spinal/epidural → proceed with GA and RSI.
5. **Postoperative Vigilance is Critical**
   * Preeclampsia/sepsis can worsen postpartum – monitor for 24hrs in HDU.
6. **Adapt to Resource Limitations Without Compromising Safety**
   * Improvise with available equipment (e.g., T-piece resuscitator for preterm neonates) while awaiting retrieval.

***

#### **6 Key Phrases Examiners Expect**

1. **"Maternal resuscitation comes first – the fetus depends on maternal stability."**
   * Demonstrates prioritization in obstetric emergencies.
2. **"I avoid ergometrine due to hypertensive risks in preeclampsia."**
   * Shows knowledge of context-specific contraindications.
3. **"I’ll use phenylephrine to maintain uteroplacental perfusion during hypotension."**
   * Highlights physiological understanding of pregnancy hemodynamics.
4. **"Magnesium is for seizure prophylaxis, not just treatment."**
   * Reinforces guideline-based management of preeclampsia.
5. **"I’ve prepared for the worst while hoping for the best – all equipment is checked."**
   * Reflects anticipatory planning in resource-limited settings.
6. **"I document resource limitations but maintain the highest standard possible."**
   * Balances realism with professional responsibility.
