Approach to the Critical Patient

Airway and breathing

Airway threats from envenomation

Hemodynamic stabilization

Hemodynamic instability patterns

Severity grading and escalation triggers

Envenomation grade classification

Escalation triggers

Monitoring and consults

Monitoring bundle

Immediate consultations

History

Sting circumstances

Exposure context

Scorpion description

Symptom characterization

Local symptoms

Systemic progression

Autonomic symptoms

Risk factors

Patient-level risk factors

Species and geographic risk

Prior antivenom exposure

Alarm features

Red flag history elements

Physical Exam

Vital signs

Hemodynamic pattern

Sting site examination

Local findings

Neurologic and cranial nerve exam

Cranial nerve findings (Grade 3 hallmarks)

Motor and neuromuscular findings

Oropharyngeal and airway exam

Airway assessment

Cardiovascular exam

Cardiac findings

Skin exam

Cutaneous findings

Differential Diagnosis

Envenomation and toxidrome mimics

Arthropod envenomation

Toxic syndromes

Neurologic mimics

Central nervous system causes

Anaphylaxis

Allergic reaction spectrum — ICD-10 T78.2

Laboratory Tests

Initial labs for Grade 2 and above

Electrolytes and renal function

Cardiac biomarkers

Lipase

Liver function tests

Hematologic and coagulation

Complete blood count

Coagulation studies

Muscle and perfusion markers

Creatine kinase

Urinalysis

Lactate

Grade 1 laboratory approach

No labs required for isolated Grade 1 envenomation

Diagnostic Tests

Scoring Systems

Envenomation severity grading

MRI

Brain MRI indications

CT

CT head

CT chest

Ultrasound

Point-of-care echocardiography (POCUS)

Formal echocardiography

ECG — included under diagnostic testing

Disposition

Grade-based disposition

Grade 1 disposition

Grade 2 disposition

Admission and ICU criteria

ICU admission indications for Grade 3 to 4

Pediatric ICU for all children with systemic symptoms (Grade 2+)

Transfer criteria

Transfer indications

Specialist consultations

Required consultations by grade

Treatment

Initial stabilization (all grades)

Universal initial management

Grade 1 treatment

Analgesia for local pain

Grade 2 treatment

Parenteral analgesia

Benzodiazepines for agitation and muscle spasm

Antihypertensive therapy

Grade 3 to 4 antivenom therapy

Anascorp (centruroides immune F(ab')2) — FDA-approved antivenom

Anaphylaxis precautions for Anascorp

Antivenom use with benzodiazepines caution

Cardiovascular management in severe envenomation

Cardiogenic shock treatment

Pulmonary edema management

Electrolyte management

Airway management

Intubation indications

Rapid sequence intubation

Post-intubation management

Special Populations

Pregnancy

Maternal and fetal considerations

Geriatric

Age-related physiologic vulnerabilities

Pediatrics

Children under 5 — highest risk group

Weight-based dosing

PICU admission criteria

Background

Epidemiology

Global burden

United States epidemiology

Severity distribution

Mortality from scorpion myocarditis

Pathophysiology

Venom composition and ion channel toxicity

Cardiovascular pathophysiology

Neuromuscular pathophysiology (Centruroides)

Cardiac conduction effects

Therapeutic Considerations

Antivenom mechanism and evidence

Benzodiazepine rationale

Prazosin for cardiovascular management

Hemodynamic agent selection rationale

Patient Discharge Instructions

copy discharge instructions

Scorpion sting discharge instructions

What to expect at home

Pain management at home

Prevention — how to avoid future stings

Follow-up

Return to emergency department red flags

References

Guidelines and key sources

Herness J, Snyder MJ, Newman RS. Arthropod Bites and Stings. American Family Physician. 2022. PMID 35977137

Boyer LV, Theodorou AA, Berg RA, et al. Antivenom for Critically Ill Children with Neurotoxicity from Scorpion Stings. NEJM. 2009

Isbister GK, Bawaskar HS. Scorpion Envenomation. New England Journal of Medicine. 2014

Abroug F, Ouanes-Besbes L, Tilouche N, Elatrous S. Scorpion Envenomation: State of the Art. Intensive Care Medicine. 2020. PMID 32125457

Boyer L, Degan J, Ruha AM, et al. Safety of Intravenous Equine F(ab')2: Insights Following Clinical Trials Involving 1534 Recipients of Scorpion Antivenom. Toxicon. 2013. PMID 23916602

Fereidooni R, Shirzadi S, Ayatizadeh SH, et al. Scorpion Envenomation-Associated Myocarditis: A Systematic Review. PLoS Neglected Tropical Diseases. 2023. PMID 37018229

Rebahi H, Ba-M'hamed S, Still ME, et al. Clinical Features and Prognosis of Severe Scorpion Envenomation in Children. Pediatrics International. 2022. PMID 33682212

Almeida ACC, Carvalho FM, Mise YF. Risk Factors for Fatal Scorpion Envenoming Among Brazilian Children. Transactions of the Royal Society of Tropical Medicine and Hygiene. 2021. PMID 34352889

Osnaya-Romero N, et al. Serum Level of Scorpion Toxins, Electrolytes and ECG Alterations in Mexican Children. Toxicon. 2016. PMID 27693586

Hewett Brumberg EK, Douma MJ, et al. 2024 American Heart Association and American Red Cross Guidelines for First Aid. Circulation. 2024

FDA Drug Label: Anascorp (Centruroides Immune F(ab')2). DailyMed. Updated 2013