ESI
Abbreviation with 5 meanings
| Stands for | Emergency Severity Index |
|---|---|
| Meanings | 5 |
| Categories | Medical, Science & Engineering, Law & Legal |
ESI has five meanings. The most common are Emergency Severity Index (emergency medicine) and Epidural steroid injection (musculoskeletal & rheumatology); it can also stand for Employer-sponsored insurance, Electrospray ionization and Electronically stored information.
Meanings of ESI at a glance
| # | ESI stands for | Context |
|---|---|---|
| 1 | Emergency Severity Index | Medical › Emergency Medicine |
| 2 | Epidural steroid injection | Medical › Musculoskeletal & Rheumatology |
| 3 | Employer-sponsored insurance | Medical › Health Insurance |
| 4 | Electrospray ionization | Science & Engineering › Chemistry |
| 5 | Electronically stored information | Law & Legal › Litigation |
1. Emergency Severity Index
Medical · Emergency Medicine Abbreviations
Five-level emergency department triage system ranking patients from level 1 (immediate lifesaving intervention) to level 5 (no resources needed), based on acuity and expected resources. It is the most widely used triage tool in US EDs.
Example: Triage: ESI 2, chest pain with diaphoresis, ECG within 10 minutes.
Developed in 1998 by emergency physicians Richard Wuerz and David Eitel and now maintained by the Emergency Nurses Association. Levels 3 to 5 depend on how many resources, such as labs or imaging, the patient will need. In pain medicine ESI means epidural steroid injection.
2. Epidural steroid injection
Medical · Musculoskeletal & Rheumatology Abbreviations
Injection of corticosteroid and often local anesthetic into the epidural space around inflamed spinal nerve roots, usually under fluoroscopic guidance, to relieve radiating arm or leg pain from disc herniation or stenosis. Relief is often temporary but can bridge recovery.
Example: L5 radiculopathy from HNP, 8 weeks of PT; right L5–S1 transforaminal ESI scheduled.
Approaches include transforaminal, interlaminar and caudal. In 2014 the FDA required warnings that epidural steroid injections can rarely cause serious neurological events such as stroke and paralysis. Evidence supports short-term benefit for radicular pain but not for axial back pain alone. In emergency medicine ESI means the Emergency Severity Index triage system.
3. Employer-sponsored insurance
Medical · Health Insurance Abbreviations
Health coverage offered through an employer or union, the largest source of health insurance in the United States, covering roughly half of the population. Employers typically pay most of the premium, and employee shares are usually deducted pre-tax.
Example: ESI premiums for family coverage averaged more than $25,000 a year in recent surveys.
The link between jobs and health coverage grew during World War II, when wage controls led employers to compete with benefits, and a 1954 tax change made employer premiums excludable from income. That exclusion is one of the largest US tax expenditures. In emergency departments ESI means the Emergency Severity Index triage scale.
4. Electrospray ionization
Science & Engineering · Chemistry Abbreviations
Ionization technique that sprays a liquid through a charged needle, producing fine droplets that evaporate and leave gas-phase ions, often carrying multiple charges. ESI lets mass spectrometers analyze large biomolecules and is the standard interface between liquid chromatography and mass spectrometry.
Example: ESI in positive mode gave the protonated molecule at m/z 310.2.
John Fenn developed ESI for biomolecules in the 1980s, describing it as giving "wings to molecular elephants," and shared the 2002 Nobel Prize in Chemistry. Because large molecules pick up many charges, a 50,000-dalton protein can appear at m/z values of only 1,000 to 2,000, within the range of ordinary analyzers.
5. Electronically stored information
Law & Legal · Litigation Abbreviations
Any information created, stored or used in digital form, including email, text messages, databases, documents, spreadsheets, social media posts, chat logs and metadata, that may be subject to discovery. The term entered the Federal Rules of Civil Procedure in amendments effective December 1, 2006.
Example: The parties agreed on custodians, date ranges and search terms for ESI at the Rule 26(f) conference.
Rule 26(b)(2)(B) limits discovery of ESI that is not reasonably accessible because of undue burden or cost, and Rule 37(e), revised in 2015, governs sanctions for failing to preserve it. ESI protocols set production formats, deduplication and privilege procedures. The broader process is called e-discovery.
Related abbreviations
More emergency medicine abbreviations
- EMTALA – Emergency Medical Treatment and Labor Act
- ENA – Emergency Nurses Association
- ENPC – Emergency Nursing Pediatric Course
- EP – Emergency physician
- FAST – Focused assessment with sonography for trauma
- FB – Foreign body
- GLF – Ground-level fall
- GSW – Gunshot wound
See all 97 emergency medicine abbreviations →
More musculoskeletal & rheumatology abbreviations
- DJD – Degenerative joint disease
- DM – Dermatomyositis
- DMARD – Disease-modifying antirheumatic drug
- DRF – Distal radius fracture
- FAI – Femoroacetabular impingement
- FM – Fibromyalgia
- FOOSH – Fall on outstretched hand
- FRAX – Fracture Risk Assessment Tool
See all 71 musculoskeletal & rheumatology abbreviations →
This entry is for general education and is not medical or legal advice. Abbreviation use varies between institutions; always confirm in context.