28.3 Ophthalmic Emergencies, First Aid, Vital Signs & CPR

Chemical injury: the protocol that overrides everything

Irrigate first. Take the history and the acuity afterwards. This is the one situation in ophthalmology where measuring visual acuity is deliberately deferred, because every second of contact time causes further damage.

1. Begin irrigation immediately with sterile saline, lactated Ringer's or, if nothing else is available, clean water. Do not delay to find the ideal fluid.
2. Instil topical anaesthetic if available to allow the patient to keep the eye open, but do not delay irrigation to obtain it.
3. Retract the lids and irrigate the fornices, having the patient look in all directions so no recess is missed.
4. Evert the upper lid and sweep for retained particulate matter — solid alkali such as lime or cement lodges in the fornix and continues to burn.
5. Irrigate for at least 15 to 30 minutes, continuously.
6. Check the pH with litmus paper in the inferior fornix, 5 minutes after stopping irrigation so the irrigating fluid itself is not measured.
7. Continue irrigating until the pH is neutral — around 7.0 to 7.4 — rechecking at intervals.
8. Then measure acuity, take the history, and have the clinician examine the eye.
9. Do not neutralise an alkali with acid or vice versa — the reaction is exothermic and causes further injury.

Alkali versus acid:

Hydrofluoric acid is the exception among acids: it penetrates like an alkali and is treated as a severe injury.

Other ocular emergencies

Acute drug reactions

Vasovagal syncope is by far the most common event in an eye clinic, typically at injection or during angiography. Signs: pallor, sweating, nausea, slow pulse, feeling faint. Action: lie the patient flat and elevate the legs, loosen tight clothing, reassure, monitor pulse and blood pressure, and do not stand them up until fully recovered.

Allergic reaction. Localised itch, rash and urticaria — stop the agent, inform the clinician, observe.

Anaphylaxis — rare with fluorescein but possible, and the one everyone must be able to act on. Signs: rapid onset with airway compromise (stridor, hoarseness, throat tightness), breathing difficulty (wheeze, hypoxia), circulatory collapse (hypotension, tachycardia, pallor), with or without urticaria and angio-oedema.

Action:

1. Call for emergency help immediately.
2. Stop the causative agent.
3. Intramuscular adrenaline into the anterolateral thigh — the standard adult dose is 0.5 mg (0.5 mL of 1:1000), repeated after 5 minutes if needed. Administration follows clinic protocol and scope of practice.
4. Lie the patient flat with legs raised unless breathing is compromised, in which case sit them up.
5. High-flow oxygen if available; monitor airway, breathing, circulation.
6. Antihistamines and steroids are adjuncts only and never delay adrenaline.

Fluorescein-specific: nausea affects a meaningful minority and usually settles within a minute; extravasation at the injection site causes local pain and staining and requires stopping the injection; and the yellow skin and urine are expected.

Vital signs

Measuring and recording vital signs is an explicit blueprint task.

Blood pressure technique errors that matter: a cuff that is too small reads falsely high; the arm must be supported at heart level; the patient should be seated and rested for five minutes, feet flat, not talking; and a single high reading is repeated before it is acted upon. Record the arm used and the patient's position.

When to escalate a blood pressure immediately: a systolic over about 180 or a diastolic over about 120, particularly with headache, visual symptoms, chest pain or shortness of breath, needs urgent clinical assessment rather than a routine letter to the family doctor.

Basic life support

The blueprint names performing cardiopulmonary resuscitation. Certification must be current and obtained through an accredited provider; the outline below is the adult sequence and does not replace hands-on training.

1. Ensure the scene is safe.
2. Check responsiveness — tap and shout.
3. Call for help and send for the emergency team and an automated external defibrillator (AED).
4. Check breathing and pulse for no more than 10 seconds. Agonal gasping is not normal breathing.
5. Begin chest compressions — centre of the chest, at least 5 cm (2 inches) deep in an adult, at 100 to 120 per minute, allowing full recoil, minimising interruptions.
6. 30 compressions to 2 rescue breaths for a single rescuer with a barrier device; compression-only CPR is acceptable and effective for untrained or unwilling rescuers.
7. Attach the AED as soon as it arrives, follow its prompts, and resume compressions immediately after any shock.
8. Continue until the patient shows signs of life, the emergency team takes over, or you are physically unable to continue.

Choking: for a conscious adult with severe obstruction, alternate back blows and abdominal thrusts; if they become unresponsive, begin CPR.

Clinic preparedness is the technologist's routine contribution: know where the emergency trolley, AED, oxygen and eyewash station are; check that the emergency equipment is in date and functional according to the schedule; know the emergency number and the escalation protocol; and take part in drills. Equipment that nobody can find is equipment that does not exist.