- Standard pre-assessment for emergency surgery should take place, without unduly delaying surgery
- Simple analgesia should be administered to reduce pain-induced rises in IOP
- Opioids may be used judiciously, as excessive administration can cause vomiting and consequent rises in IOP
- Other factors affecting IOP should be addressed, such as:
- Hypertension
- Hypoxia & hypercarbia
- Vomiting
- Paediatric patients: crying | screaming | rubbing eyes | breath-holding
Anaesthesia for Emergency Ophthalmic Surgery
Anaesthesia for Emergency Ophthalmic Surgery
This topic has come up in three of the four Ophthalmic SAQ/CRQ questions since 2017, so is well worth covering.
In their usual scathing fashion, the examiner's reports from said exams comment on: 'a lack of experience in traumatic eye injuries'' and '...candidates not displaying much knowledge about the clinical aspects of anaesthetizing a patient for an emergency eye operation.'
Resources
- The principal aim in the management of penetrating eye injury is to avoid increased IOP, which may lead to vitreous extrusion, haemorrhage and lens prolapse
- In the unfasted patient, theoretical options include:
- Delaying surgery if felt appropriate ± pre-medicating with prokinetics and antacids
- Classical RSI with suxamethonium, which causes transient 5 - 10mmHg increase in IOP for 5 - 10mins and theoretical risk of vitreous extrusion
- Modified RSI with rocuronium
- Given that most will use a rocuronium RSI, a more pertinent step is obtunding the pressor response to laryngoscopy and intubation
- Options include:
- Fentanyl 3 - 5μg/kg
- Remifentanil Ce 3 - 5ng/ml
- Alfentanil 10 - 20μg/kg
- Lidocaine 1 - 1.5mg/kg
- Esmolol 3 - 5μg/kg
- Further doses of induction agent
- NB local anaesthetic blocks are contraindicated
- Ongoing steps to minimise increases in IOP are required
- These are analogous to other head and neck surgeries, and include:
- Slight head-up tilt | minimise airway pressures
- Maintain low-normal ETCO2
- Avoid venous congestion e.g. from tube ties
- Maintain suitable depth of anaesthesia and paralysis
- Consider use of mannitol or acetazolamide
- Aim to minimise coughing, bucking or retching on emergence
- Deep extubation in spontaneously breathing patient
- Airway exchange ETT for LMA whilst deep
- Extubate with background opioid e.g. remifentanil infusion
- IV lidocaine
- Minimise risk of retching post-operatively
- Temporary insertion of orogastric tube to suction stomach contents
- Prophylactic, multi-modal antiemetics
- Mulit-modal analgesia to minimise opioid load
- Patients are often suitable for inpatient stay on an ophthalmology ward