01Approach to the Critical Patient/attcp68

Immediate priorities

›Recognition and isolation of threat

›High pretest probability triggers

›Known or suspected aerosol spore release

›Suspicious mail or package handling

›Cluster of severe febrile respiratory illness

›Biphasic course recognition

›Flu-like prodrome over hours to days

›Abrupt fulminant deterioration with shock

›Standard precautions adequate

›Not transmitted person to person

›Decontamination if visible spore exposure

›Airway and breathing threats

›Respiratory failure

›SpO2 < 90% on room air

›PaO2 < 60 mmHg

›Mediastinal compression

›Stridor from tracheal compression

›Massive mediastinal lymphadenopathy

›If airway compromise, early intubation

›Anticipate difficult anatomy from edema

›Rapid sequence intubation preparation

›Circulation and toxemia threats

›Distributive shock physiology

›SBP < 90 mmHg

›MAP < 65 mmHg

›Toxin-mediated cardiovascular collapse

›Refractory hypotension

02History/hx56

Presentation pattern

›Biphasic illness

›Prodromal phase

›Fever and malaise

›Myalgia and fatigue

›Nonproductive cough

›Transient improvement

›Brief apparent recovery in some patients

›False reassurance pitfall

›Fulminant phase

›Abrupt high fever and dyspnea

›Drenching diaphoresis

›Shock and cyanosis

›Symptom characterization

›Respiratory complaints

›Dyspnea

›Pleuritic chest pain

›Chest tightness

›Systemic complaints

›Drenching sweats

›Headache

›Nausea and vomiting

›Critical negative

›Rhinorrhea characteristically absent

›Key distinction from influenza and URI

Exposure and timing

›Incubation window

›Typical onset

03Physical Exam/exam62

Vitals and general

›Stability snapshot

›Temperature

›Fever present in all 2001 cases

›Hyperpyrexia in fulminant phase

›Heart rate

›Tachycardia in majority at presentation

›Discriminating feature from ILI

›Blood pressure

›SBP < 90 mmHg in fulminant phase

›MAP < 65 mmHg

›Oxygenation

›Hypoxemia in majority at presentation

›Cyanosis as late marker

›General appearance

›Toxic and ill-appearing

›Diaphoresis

›Increased work of breathing

›Subcutaneous edema

›Chest and neck swelling in advanced disease

›Reflects mediastinal involvement

Organ-system exam

›Respiratory exam

›Lung auscultation

›Surprisingly clear early

›Decreased breath sounds with effusions

›Upper airway

›Stridor from mediastinal compression

04Differential Diagnosis/ddx35

Life threats and infectious mimics

›Respiratory infections

›Community-acquired pneumonia

›ICD-10 J18.9 association

›Distinguished by mediastinal widening and absent rhinorrhea

›Influenza and ILI

›Rhinorrhea and myalgias prominent

›Anthrax favors tachycardia and high hematocrit

›COVID-19

›Overlapping constitutional symptoms

›PCR differentiation

›Other systemic threats

›Hemorrhagic meningitis other causes

›Bacterial meningitis

›CSF analysis differentiation

›Sepsis from other sources

›ICD-10 A41.9 association

›Blood culture differentiation

Widened mediastinum differentials

›Vascular causes

›Aortic dissection or ruptured aneurysm

›No infectious prodrome

›CT angiography differentiation

›Superior vena cava syndrome

›Malignancy-related widening

›Facial and arm edema

›Mediastinal infection and infiltration

›Acute bacterial mediastinitis

05Laboratory Tests/lt55

Microbiologic studies

›Blood cultures

›Single most useful test

›Obtain before antibiotics

›Growth in 6 to 24 hours

›Rapid sterilization

›Negative after 1 to 2 antibiotic doses

›Timing critical to yield

›Laboratory communication

›May be dismissed as B cereus contaminant

›Specify anthrax suspicion to micro lab

›Confirmatory testing

›Peripheral blood Gram stain

›Large gram-positive bacilli in massive bacteremia

›Box-car morphology

›PCR at reference laboratory

›Definitive identification

›Laboratory Response Network

›Pleural fluid studies

›Gram stain and culture 83% positive pre-antibiotics

›Lethal factor detection by spectrometry

Hematology and chemistry

›Complete blood count

›Hemoconcentration

›Elevated hematocrit

›Discriminating feature from CAP

›White cell count

›Normal or mildly elevated

06Diagnostic Tests/dt60

Scoring Systems

›Discriminating clinical tools

›Kyriacou chest radiograph algorithm

›Mediastinal widening or pleural effusion plus altered mental status plus elevated hematocrit

›100% sensitive and 98.3% specific versus CAP

›Kuehnert ILI discrimination score

›Tachycardia and high hematocrit

›Low albumin and low sodium

›Absence of rhinorrhea and myalgias

›Score >= 4 captured all 11 anthrax cases

›Excluded 96% of ILI

›Severity and sepsis adjuncts

›qSOFA at bedside

›RR >= 22 per minute

›SBP <= 100 mmHg

›Altered mental status

›Limitations

›Not anthrax-specific

›Clinical trajectory supersedes single score

›ACEP Level C recommendation for adjunctive use

MRI

›MRI role

›Limited acute utility

›Availability constraints

›Unsuitable for unstable patient

›Neuroimaging indications

›Suspected hemorrhagic meningoencephalitis

›Brain MRI shows hemorrhage and edema

07Disposition/dispo31

Level of care selection

›ICU admission

›All suspected inhalation anthrax

›No role for outpatient symptomatic management

›Hemodynamic monitoring required

›Ventilatory and shock needs

›Mechanical ventilation readiness

›Vasopressor support

›Procedural needs

›Pleural drainage

›Pericardiocentesis

›Specialist coordination

›Infectious diseases mandatory

›Antimicrobial selection

›Antitoxin authorization

›Critical care and surgery

›Pulmonology and critical care

›Cardiothoracic surgery for effusions

Exposed contacts and notification

›Asymptomatic exposed individuals

›Outpatient prophylaxis candidate

›Close follow-up

›Return precautions for any febrile illness

›Prophylaxis components

›60-day antimicrobial course

›AVA vaccine 3-dose series

›Mandatory notification

›Public health reporting

08Treatment/t83

Initial stabilization

›Resuscitation

›Hemodynamic support

›Aggressive IV crystalloid

›Norepinephrine for refractory shock

›Respiratory support

›Oxygen titrated to SpO2 target

›Lung-protective ventilation if intubated

›Sepsis bundle

›Blood cultures before antibiotics

›Lactate-guided resuscitation

Antimicrobial therapy

›Systemic anthrax with possible meningitis

›Bactericidal fluoroquinolone

›Ciprofloxacin 400 mg IV every 8 hours

›Levofloxacin or moxifloxacin alternative

›CNS-penetrating beta-lactam

›Meropenem 2 g IV every 8 hours

›Added until meningitis excluded

›Protein synthesis inhibitor

›Linezolid 600 mg IV every 12 hours

›Inhibits toxin production

›Systemic anthrax with meningitis excluded

›Bactericidal agent

›Ciprofloxacin 400 mg IV every 8 hours

›Single fluoroquinolone acceptable

›Protein synthesis inhibitor

›Linezolid 600 mg IV every 12 hours

09Special Populations/sp48

Pregnancy

›Treatment considerations

›Life-threatening disease priority

›Standard combination therapy not withheld

›Ciprofloxacin acceptable when indicated

›Agent caution

›Doxycycline weighed against fetal risk

›Use when benefit outweighs risk in severe disease

›Supportive measures

›Maternal SpO2 >= 95% when feasible

›Fetal monitoring at viable gestation

›Prophylaxis approach

›Ciprofloxacin preferred for PEP

›60-day course

›Doxycycline alternative with counseling

›Vaccine consideration

›AVA per public health guidance

›Risk-benefit individualized

Geriatric

›Severity and presentation

›Higher complication risk

›Comorbid COPD and diabetes

›Reduced physiologic reserve

›Atypical features

›Delirium as early sign

›Blunted febrile response possible

›Medication adjustment

›Renal dosing

10Background/b55

Epidemiology

›Burden and lethality

›Category A bioterrorism agent

›Most lethal form of anthrax

›Aerosol weaponization concern

›Case fatality

›Historically 89 to 90%

›Reduced to approximately 45% in 2001 attacks

›Rapidity of death

›Fatal cases had median hospital stay of 1 day

›All untreated fulminant 2001 cases died

›Complication frequency

›Major complications

›Sepsis in approximately 70%

›Secondary meningitis in approximately 33%

›Additional complications

›Coagulopathy in approximately 33%

›Respiratory failure requiring ventilation in approximately 23%

Pathophysiology

›Organism and entry

›Bacillus anthracis spores

›Inhaled into alveoli

›Engulfed by alveolar macrophages

›Lymphatic transport

›Germination in mediastinal lymph nodes

›Hemorrhagic mediastinitis

›Toxin-mediated injury

›Tripartite toxin

11Patient Discharge Instructions/pdi21

copy discharge instructions

›Postexposure prophylaxis home care

›Take antibiotics every day for the full 60 days

›Do not stop early even if you feel well

›Complete all 3 vaccine doses if offered

›Keep all follow-up appointments

›Warning signs to return to ER immediately

›Fever or chills

›New cough or trouble breathing

›Drenching sweats

›Chest pain

›Severe headache or neck stiffness

›Confusion or severe drowsiness

›Fainting or feeling like you may pass out

›Medication safety

›Report rash, swelling, or trouble breathing as possible allergy

›Report severe diarrhea

›Avoid stopping the antibiotic without medical advice

›Follow up

›Clinician follow up as scheduled during prophylaxis

›Public health may contact you about exposure

›Report any new illness in household contacts

12References/r11

Guidelines and key sources

›Guideline sources

›CDC Guidelines for Prevention and Treatment of Anthrax 2023

›Anthrax as a Biological Weapon Updated Recommendations JAMA 2002

›Clinical Management of Potential Bioterrorism-Related Conditions NEJM 2015

›Landmark studies and reviews

›Hendricks systematic review of hospitalized anthrax 1880 to 2018

›Kyriacou clinical algorithm distinguishing anthrax from CAP

›Kuehnert clinical features discriminating inhalational anthrax

›Coding standards

›ICD-10 A22.1 pulmonary anthrax

›SNOMED CT inhalation anthrax disorder concept

Evidence & Review

Evidence & Review