2023.1 Day 2 VIVA 5
It is 7 pm in Scenarioville and your next case is a 22-year-old for a Laparoscopic Appendicectomy. He is a smoker, with a past medical history of childhood asthma. He weighs 80 Kgs (BMI=25), and his airway appears normal.
He has nausea but is well fasted and has no family history of anaesthetic issues. Anaesthesia was induced with Propofol, Fentanyl and Rocuronium. The patient has been intubated without incident.
Before surgery starts you notice elevated airway pressures on the machine.
What are the potential causes and what would be your approach in identifying them?
Causes of elevated Pressure:
Obstruction:
Endotracheal tube (ETT) kinking or malposition or cuff herniation (e.g., tube against the wall of the airway).
Secretions or mucus plug in the ETT.
Bronchospasm (especially in patients with a history of asthma).
Ventilation system issues:
Circuit problems (e.g., disconnection, kink, or malfunction of the ventilator or tubing).
Mechanical causes:
Increased intra-abdominal pressure due to insufflation for laparoscopy.
Pneumothorax or tension pneumothorax (rare, but should be considered).
Lung pathology:
Pulmonary oedema or aspiration (check for signs of aspiration or difficulty with ventilation).
Obstructive or restrictive lung disease (check for wheezing or signs of asthma exacerbation).
How would you approach identifying the cause of the elevated airway pressures?
DABCDE Initial Assessment
Ensure no immediate life-threatening conditions
Rule out tension pneumothorax
Quickly assess patient's overall clinical status
Commence simultaneous assessment and management.
Equipment and Circuit Evaluation
Disconnect from ventilator
Bag the patient manually to:
Assess lung compliance
Eliminate potential machine issues
Circuit Inspection
Check for kinks or loose connections
Verify all ventilator components are functioning correctly
Endotracheal Tube (ETT) Assessment
Position and Patency
Auscultate chest
Check for equal breath sounds
Detect unequal sounds suggesting ETT malposition
Capnography evaluation
Assess waveform shape
ETT Depth Verification
Confirm correct tube placement
Suctioning
Clear secretions or mucus plugs
Assess ETT patency
Bronchospasm Evaluation
Clinical Signs
Listen for wheezing
Assess prolonged expiration
Monitor rising PaCO₂
Interventions
Administer bronchodilators if needed
Consider underlying causes (asthma, anaphylaxis)
Pneumothorax Exclusion
Physical Signs
Unilateral breath sounds
Hypotension
Distended abdomen (especially in laparoscopic cases)
Diagnostic Approach
Perform chest auscultation
Consider chest X-ray (CXR)
Ventilator Settings Optimization
Verify
Positive End-Expiratory Pressure (PEEP)
Tidal volumes
Cuff Management
Temporarily deflate cuff to assess airway pressures
Determine if ETT-related obstruction exists
Continuous Monitoring
Reassess patient's respiratory status
Monitor vital signs
Be prepared for immediate interventions
Despite your interventions, the patient develops widespread erythema, facial swelling, hypotension (BP 70/40), and worsening bronchospasm.
What is happening, and how will you manage this?
Diagnosis:
Grade 3 Anaphylaxis (hypotension + bronchospasm + cutaneous signs).
Immediate Management:
Call for Help – Anaesthetic assistant, extra support.
Adrenaline:
IV Bolus: 50–100 mcg (0.5–1 mL of 1:10,000) every 1–2 mins.
Infusion: If refractory, start at 0.05–0.1 mcg/kg/min.
Stop Potential Triggers:
Antibiotics (e.g., cefazolin), NMBAs (rocuronium), latex.
Fluid Resuscitation:
500–1000 mL crystalloid bolus.
Secondary Drugs:
Hydrocortisone 200 mg IV
The patient stabilises after two more adrenaline boluses.
The surgeons ask if they can proceed. How do you respond?
The case should be postponed unless it’s life-threatening.
How would you manage the transfer of this patient out of Scenarioville for further care?
Clinical Stabilisation:
Ensure the patient is haemodynamically stable, with normal oxygenation and ventilation.
Ongoing management of anaphylaxis, including adrenaline and fluid resuscitation, if required.
Oxygen support (e.g., non-invasive ventilation or intubation) if necessary during transfer.
Communication and Coordination:
Inform the receiving facility (e.g., tertiary hospital or ICU) of the patient’s condition, treatment administered, and potential ongoing requirements.
Ensure anaesthesia and emergency teams are involved in the handover.
Transport considerations:
Use air or ground transport with appropriate medical supervision.
Ensure continuous monitoring of vital signs and blood gases.
Secured IV access, medications for resuscitation, and adrenaline autoinjectors on hand during transport.
What additional treatment is necessessary?
Cardiovascular monitoring for shock or arrhythmias.
Observation for at least 4-6 hours after resolution to detect biphasic anaphylaxis.
Mast Cell Tryptase:
Sample at 1h, 6h, and 24h post-onset.
Patient education on the use of epinephrine autoinjectors for future emergencies and referral for allergy testing.
Incident reporting and a post-crisis debrief with the team to review the management approach.
Allergy Referral:
Skin prick testing for NMBA/antibiotic
What would you include in the incident report and debriefing after this event?
Incident report should include:
Timeline of the event, including when anaphylaxis was first suspected, interventions initiated, and the patient’s response.
Medications given, doses, and their timing (e.g., adrenaline, fluids, corticosteroids).
Patient outcome and transfer details.
Debriefing session:
Review the management process to identify any opportunities for improvement.
Discuss human factors, such as communication and decision-making.
Plan for future training or updates to the protocol, if necessary.
Consider emotional support for the staff involved in the crisis and patient care.
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