Background
Patients with head injuries sometimes present with a closed, swollen eye. We rightly worry about intracranial bleeding in these cases, but there are some important eye injuries to consider too. Dr Anna MacDonald?[1]? suggests that the following four time-critical, sight-threatening diagnoses should be foremost in our minds when assessing a patient with blunt ocular trauma...
Retrobulbar haemorrhage with orbital compartment syndrome Globe rupture Retinal detachment High grade ('8-ball') hyphema with acute glaucoma
The first of these, retrobulbar haemorrhage (RBH), is a fairly rare condition and many of us will be unfamiliar with its features and recommended management. A recent paper in the EMJ tried to assess the competency of UK ED docs in treating RBH, and identified some issues...
The paper
Edmunds MR, Haridas AS, Morris DS, Jamalapuram K. Management of acute retrobulbar haemorrhage: a survey of non-ophthalmic emergency department physicians. Emerg Med J 2019;36(4):245-247 ?[2]?
An online survey was sent to ED doctors of all training grades across the UK. It comprised a case vignette (of someone with the clinical features of retrobulbar haemorrhage), followed by questions on the diagnosis and management of such cases.
It was answered by 190 doctors, 46% of whom were consultants. RBH was correctly diagnosed by 83%, but only 39% had encountered a case of RBH and only 37% said they would be happy to perform a lateral canthotomy themselves.
79% indicated that they would initially obtain a CT scan rather than performing lateral canthotomy. The authors reminded us that a CT scan is not necessary to diagnose RBH, and that obtaining one can lead to delays and harm for the patient.
A whopping 92% felt that more training in performing lateral canthotomy was required for ED physicians.
The bottom line
The authors of this paper recommend that RBH management and in particular the skill of lateral canthotomy is added to the UK Emergency Medicine training curriculum
Why this is a serious condition
The problem with RBH is that, unchecked, pressure behind the eye builds and can lead to orbital compartment syndrome. Arterial supply to the optic nerve is compromised once intraocular pressure reaches 40mmHg, and irreversible visual loss ensues. This can occur in as little as 1 hour from the development of symptoms.
How can we recognise retrobulbar haemorrhage?
The first signs are proptosis of the eye and reduced eye movements, compared to the other side. These are the so-called 'mechanical signs' of RBH. Once the optic nerve is affected, you get RAPD, followed by a reduction in visual acuity and loss of pupil responses (the 'ischaemic signs' of RBH).
What is the correct management of retrobulbar haemorrhage?
The ideal treatment is to decompress the orbit before compartment syndrome causes irreversible visual loss. The procedure for doing this is called lateral canthotomy. The equipment needed is actually pretty basic. The steps are detailed below, but it's easier to watch the embedded video (please use viewer discretion, as there are gory scenes!).
Infiltrate lidocaine at the lateral canthus Crush the lateral canthus with a clamp or needle holder Leave in place for 1 minute (this devascularises the area and reduces bleeding) Cut the lateral canthus straight across by 1-2cm Use foreceps to hold the lower eyelid out Slide back and forth to feel for a 'guitar string' (the inferior crus) and cut this with scissors - you'll know you've got it when the lower eyelid becomes very mobile If intra-ocular pressure is still high, repeat the procedure with the superior crus
This is a rare procedure - why bother learning it?
Well, because it's an emergency and we're emergency docs!
But seriously, there are several conditions that are rare but serious, and we need to be familiar with them: aortic dissection, tension pneumothorax, Ludwig's angina, etc. Likewise, there are several procedures that rarely need to be performed but we need to be competent to attempt them: pericardiocentesis, cricothyrotomy, newborn resuscitation, etc.
Plus, it might be the middle of the night, with ophthalmology unavailable, and it might just be down to you to save your patient's sight...
More FOAMed on this...
Life in the Fast Lane: Bashed, Blind and BulgingFirst 10 EM: Lateral CanthotomyNUEM: CanthotomyEM3 Resus Drills: Lateral Canthotomy - There are some great ideas here on how to run a training session on this condition
References
Helman A. Blunt Ocular Trauma Live from The EM Cases Course [Internet]. Emergency Medicine Cases2018 [cited 2019 Jun];Available from: https://emergencymedicinecases.com/ocular-trauma/ Edmunds MR, Haridas AS, Morris DS, Jamalapuram K. Management of acute retrobulbar haemorrhage: a survey of non-ophthalmic emergency department physicians. Emerg Med J [Internet] 2019;245–7. Available from: http://dx.doi.org/10.1136/emermed-2018-207937
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