Wrong-Sided Block

Question 1

A 35-year-old male patient is undergoing rotator cuf repair surgery afer sustaining an injury while playing cricket. He is otherwise well, has no allergies, and has never had an anaesthetic before.

What are the options for anaesthetising this patient?

Answer 1

• General anaesthetic.
• General and regional anaesthetic combined.
• Regional anaesthesia awake or with sedation.

Question 2

What are the advantages of regional anaesthesia alone in patients undergoing shoulder surgery?

Answer 2

• Represents an additional choice to the patient.
• Provides excellent pain control during and after surgery.
• Allows for a shorter duration of surgery/inpatient stay.
• Avoids the side effects of opioid-based analgesic agents e.g. nausea,
  vomiting and constipation.
• Avoids the side effects and complications of general anaesthetic
  e.g. airway compromise, dental damage, postoperative pulmonary complications and hypotension.
• Allows patients to eat and drink straight after surgery.
• Facilitates a rapid turnover of patients, improving efficiency and decreasing costs for hospital.

Question 3

How would you anaesthetise this patient?

Answer 3

Preoperative:
* Perform a standard anaesthetic assessment. There is nothing in the history above that suggests significant pathology to investigate.

• Consent to the technique explaining the benefits, risks and potential complications.
• Apply full monitoring as per the AAGBI minimum monitoring standards.

Interscalene regional block:
* Position the patient supine, head up and neck rotated to contralateral side.

• Ensure full asepsis, including a hat, mask, sterile gloves and chlorhexidine 0.5% spray.
• Using a linear ultrasound probe, identify the brachial plexus at the level of the subclavian artery and follow it in a cephalad direction until the C5-C7 nerves can be identified travelling as a discrete bundle.
• “Stop before you block” moment: Confirm the correct block on the correct side for the correct patient.
• Inject local anaesthetic into the skin.
• Using an in-plane approach, inject a sufficient volume of bupivacaine
  to surround the nerves (10–15mL 0.5% bupivacaine should be sufficient) using a 50 mm echogenic block needle.
• Assessment of patient following regional block to ensure no complications.

Question 4

What is meant by an “in-plane” approach?

Answer 4

• The needle is inserted into the skin at the lateral aspect of the ultrasound probe, ensuring that the needle tip and shaft are both visible throughout the procedure.

Question 5

What are the potential complications associated with an interscalene block?

Answer 5

• Block failure.
• Phrenic nerve blockade.
• Horner’s syndrome.
• Recurrent laryngeal nerve blockade and hoarse voice.
• Nerve injury.
• Prolonged weakness/numbness.
• Local anaesthetic toxicity.
• Wrong-sided block.

Question 6

You perform the interscalene block and review the patient 5 minutes later. Unfortunately, the block was performed on the incorrect side.

What are the factors that may contribute to a wrong-sided block being done?

Answer 6

Surgical:
* Surgical mark on the incorrect side.

• Consent form indicating the incorrect side.

Anaesthetic technique:
* Block performed after induction of general anaesthesia.

Situational factors:
* Prolonged period between the WHO checklist and regional block.

• Surgical mark not visible while the block is being done.
• Inexperienced anaesthetist.
• Failure to perform a “stop before you block” moment.
• Human error due to distractions, time pressure, fatigue, stress or anxiety.

Question 7

How would you manage this incident (‘never event’)?

Answer 7

• Declare the mistake to the patient, anaesthetic assistant, anaesthetic and surgical consultants and theatre team.
• Apologise to the patient. Ensure that they are kept safe e.g. monitored if they have had any sedative medication, or woken up safely if they have had a general anaesthetic.
• Discuss with a senior anaesthetist and the theatre team regarding how to proceed; almost certainly the operation will have to be postponed.
• Document conversations with the patient and team.
• It may be appropriate for another anaesthetist to take over the case/list.
• Discuss with supervisor and medicolegal team if appropriate.
• Report the wrong-sided block as a critical incident according to local
  protocols.
• Discuss the issue with educational supervisor/college tutor as to whether further support or training is needed.