Intraoperative Assessment

Divided into:

Anaesthetic crisis assessment
Approach to intraoperative crisis.
Anaesthetic cross-check
Periodic review of patient and equipment.

Intraoperative Crisis

A standard starting sequence reduces the risk of anchoring bias by forcing a wide variety of causes to be considered early

This approach will identify the cause of almost all anaesthetic crises in 40-60s

The mnemonic is COVER ABCD - A SWIFT CHECK:

COVER ABCD is the mnemonic for patient and equipment assessment
A SWIFT CHECK is the mnemonic for potential diagnoses
C
Circulation assessment.
- Circulation
  - Check adequacy of pulse
    Commence CPR if pulseless.
  - Check capnograph for effective circulation
- Colour
  Check SpO₂ and evidence of peripheral cyanosis.
O
Oxygen assessment.
- Oxygen Supply
  Ensure inspired gas mixture is not hypoxic. Check rotameters.
- Oxygen Analysis
  ↑ FiO₂ to 100% and ensure that the oxygen analyser detects the rise in FiO₂.
V
Ventilation and vapouriser assessment.
- Hand-ventilate the lungs, assessing:
  - Circuit integrity
  - Airway patency
  - Lung and chest wall compliance
  - Capnography
- Check agent settings and levels
  - Check agent level
  - Check vapouriser is seated correctly
  - Consider wrong agent
E
- ETT assessment
  - Contamination
  - Depth
    Externally compress the tracheal cuff whilst palpating the pilot balloon.
  - Orientation
  - Consider
- Eliminate
  - Remove the anaesthetic machine from circuit
  - Hand ventilate with self-inflating bag
    - Commence TIVA if required
R
Review:
- Monitors:
  - Breathing:
    - Oxygen analyser
    - SpO₂
  - Circulation
    - ECG
    - BP
  - Disability
    - Train-of-four
  - Extremities
    - Temperature
- Equipment:
  All other equipment in contact with the patient.
  - Diathermy
  - Humidifiers
  - Warming blankets
  - Probes
  - Prostheses
Airway
- Check airway patency
- Consider:
  - Foreign body
  - Blood
    - Secretions
  - Aspiration
  - In an unintubated patient, consider:
    - Laryngospasm
  - In an intubated patient, consider:
    DOPES:
    - Dislodged
    - Obstruction
    - Pneumothorax
    - Equipment
      - Ventilator
        Consider swapping to self-inflating bag.
      - Tube
        Consider tube exchange.
    - Stacked breaths
      Dynamic hyperinflation.
Breathing
- Check:
  - Pattern
  - Adequacy
- Consider:
  - Lower airway:
    - Bronchospasm
      Dynamic hyperinflation.
  - Alveolar:
    - Oedema
    - Lobar collapse
  - Pleural:
    - Pneumothorax
    - Haemothorax
Circulation
- Check:
  - Perfusion
  - Pulse
  - Arterial pressures
  - Filling pressures
    - PEEP
    - Consider tamponade
- Consider:
  - Ischaemia
  - Arrest
Drugs
- Check:
  - Drugs given/ampoules
  - Adverse effect
- Consider:
  - Awareness
  - Drug error
  - Loss of IV
A
Note only letter in this mnemonic with four diagnoses:
- Anaphylaxis
  - Hypotension
  - Bronchospasm
  - Rash
- Awareness
  - Interpatient variability
  - Loss of agent
  - Empty vapouriser
  - IVC disconnection
- Air (in pleura)
  - Ventilatory failure
  - Circulatory failure
- Air embolus
  - Hypotension
  - Hypocarbia
S
- Surgical
  - Vagal stimulus
  - Aortocaval compression
  - Haemorrhage
  - Myocardial stimulation
- Sepsis
  - Hypotension
  - Acidosis
  - Hyperdynamic circulation
W
- Water
  - Electrolyte disturbances
- Wound
  - Trauma
  - Bleeding
  - Tamponade
  - Pneumothorax
I
- Infarction
  - Conduction
  - Arrhythmia
  - Shock
- Insufflation
  - Vagal tone
  - Loss of VR
  - Gas embolism
F
- Fat
  - Hypoxia/hypotension post induction, especially in lithotomy or post-inducation
- Full bladder
  - ↑ SNS tone
T
- Trauma
- Torniquet
  - LA toxicity
  - Bleeding
C
- Catheter
  - IVC
    - Tissued
    - Wrong drug
    - Leaks
  - Chest drain
- Cement
H
- Hyper/Hypothermia
  - Tachycardia
  - ECG changes
- Hypoglycaemia
  - Insulin
  - Fasting
  - Beta-blockade
  - Hepatic failure
E
- Embolus
  - Fat
  - Amniotic fluid
  - Clot
- Endocrine
  - Thyroid
  - Adrenal
  - Pituitary
  - Serotonin
C
- Check preoperative drugs
- Check preoperative diseases
K
- K⁺
  - Hyperkalaemia
  - Hypokalaemia
- Keep
  Asleep until new anaesthetic machine obtained.

Intraoperative Cross-Check

Using the COVER mnemonic helps it become routine

C
- Circulation
  - Check pulse
    Rate, rhythm, volume.
  - Check ETCO₂
- Colour
  - Check colour
O
- Check FiO₂
- Check circuit O₂ flows
- Check connection (e.g. if using mask via auxillary oxygen port)
V
- Check ventilation mode, RR, and V_T
- Check ETCO₂ for value and waveform
- Check ventilation pressures and waveform
- Check vaporiser filling and sttings
E
- Check tube position and security
- Check tube cuff pressure and leak
R
- Review monitors, values, and waveforms
  - Check level of tranducers
- Review equipment in use and in contact with the patient

References

Runciman WB, Kluger MT, Morris RW, et al Crisis management during anaesthesia: the development of an anaesthetic crisis management manual BMJ Quality & Safety 2005;14:e1.