Minor irritation, typified by redness, lacrimation and mild oedema
Moderate irritation, such as irritation to cornea
Severe irritation, such as corneal ulceration or perforation, can lead to blindness
Chemicals Alkaline chemicals are particularly harmful to eyes and can lead to necrosis
Why are Alkalis so Bad!! Cause disruption of eye’s protective permeability barrier (cornea) Once alkali rapidly penetrate the cornea they release collagenase that then enters the anterior chamber Acid’s don’t seem to penetrate the cornea as much as alkalis, and tend to coagulate on the surface of the eye, limiting there damage. “Hydrofluoric acid is the exemption, tends to work the same as an alkali”
History When did it occur? What is the chemical? (acid/alkali) Any first aid administered and how soon after the incident. Symptoms? E.g. loss of vision, redness, tearing, pain, photophobia, Associated injuries? E.g. skin exposure
Assessment Look for Red eye (severe alkali burns alkali burns can present as eye completely white due to total loss of conjunctival blood vessels) Signs of severe burn Decreased visual acuity Cloudy cornea Epithelial defect with fluroscein
Pre-Hospital Care Copious irrigation for at least 30mins Neutral fluid (CSL or N/saline) Try and remove foreign bodies first Main need topical anaesthetic
Emergency Department Management Irrigation ? CSL is better Morgan's Vs Nasal Oxygen Analgesia Same day Opthal r/v
Emergency Department Management Pain relief Topical is better Helps relieve blepharospasm Assist with irrigation “Tetracaine Hydrochloride 1%” Avoid repeated application
Emergency Department Management Irrigation > ASAP>Time is EYE sight Objectives of Irrigation Immediate dilution of offending agent Removal of agent Removal of foreign bodies Normalisation of anterior chamber pH
N/saline can cause more stinging compared to CSL, generally recommend in most texts
New literature heading towards CSL as has closer pH to the eye.
Some studies showed warmed fluids were better tolerated
Bottom line, not enough evidence yet!!
How long for? When do I stop? Literature recommends at least 20-30mins Stop when: When normalisation of pH,( ?7.3) Use litmus paper If pH deranged continue for another 20-30mins Symptoms improved Keep patient warm