01Approach to the Critical Patient/attcp34

Immediate priorities

›Time critical stabilization

›Escalate to resuscitation bay for hypotension or altered mental status

›Sepsis protocol if suspected systemic infection

›If airway compromise, then airway management

›Post intubation sedation and analgesia to target comfort

›If shock, then IV crystalloid bolus 20-30 mL/kg

›Norepinephrine infusion if MAP < 65 mmHg after fluids

›Pain control plan prior to joint procedures

›If severe pain, then IV opioid titration with monitoring

›Early diagnostic and source control plan

›Arthrocentesis priority before antibiotics when feasible

›If unstable or high sepsis risk, then antibiotics not delayed for aspiration

›Blood cultures x2 before antibiotics if feasible

›If antibiotics already given, then still obtain cultures

›Early orthopedic consultation for suspected septic joint

›Immediate consultation for hip, shoulder, prosthetic joint, or rapid clinical decline

›Key concepts

›Septic arthritis as joint space infection with rapid cartilage destruction

›Irreversible damage possible within 24-48 hours without drainage and antibiotics

›Diagnosis anchored on synovial fluid studies

›Culture as definitive test

›Drainage as essential therapy

›Repeated aspiration vs arthroscopic or open washout based on joint and response

Red flags and escalation

›High risk features

›Hemodynamic instability

›Lactate elevation or rising trend

02History/hx49

Symptom pattern

›Presentation pattern

›Acute monoarticular pain

›Rapid onset over hours to days

›Swelling and warmth

›Functional limitation

›Fever or chills

›Absence of fever does not exclude

›Inability to bear weight

›Hip and knee high concern

›Time course and triggers

›Symptom onset time

›Progression speed

›Recent trauma or joint procedure

›Injection or arthroscopy

›Recent infection source

›Skin and soft tissue infection

›Urinary tract infection

›Pneumonia

›Exposure risks

›Recent sexual exposure

›Gonococcal arthritis risk

›Tick exposure

›Lyme arthritis risk

›Animal bite or scratch

›Pasteurella risk

›Travel or freshwater exposure

›Unusual pathogens risk

03Physical Exam/exam41

Joint focused exam

›Local findings

›Effusion

›Ballotment where applicable

›Warmth and erythema

›Overlying cellulitis extent

›Tenderness

›Pain with minimal passive motion

›Range of motion limitation

›Pain greatest with passive ROM

›Joint specific considerations

›Hip

›Pain with internal rotation

›Shoulder

›Limited abduction and external rotation

›Wrist and hand

›Tenosynovitis signs for disseminated gonococcal infection

Systemic exam

›Vital signs and perfusion

›Fever

›Afebrile presentations in elderly and immunocompromised

›Tachycardia

›Sepsis trigger

›Hypotension

›Shock trigger

›Source exam

›Skin

›Abscess or cellulitis

04Differential Diagnosis/ddx33

Life threatening and limb threatening

›High risk differentials

›Septic arthritis

›ICD-10 M00.9

›Necrotizing soft tissue infection

›Rapid progression and pain out of proportion

›Septic bursitis

›Olecranon or prepatellar swelling

›Osteomyelitis contiguous to joint

›Persistent pain despite aspiration

›Endocarditis with septic emboli

›Bacteremia with joint symptoms

›Mimics

›Crystal arthritis

›Gout ICD-10 M10.- and CPPD ICD-10 M11.-

›Hemarthrosis

›Anticoagulation or bleeding disorder

›Reactive arthritis

›Post GI or GU infection

›Inflammatory arthritis flare

›Rheumatoid arthritis ICD-10 M06.9

›Lyme arthritis

›Large joint effusion with subacute course

›Gonococcal arthritis

›Migratory polyarthralgia or tenosynovitis

›Cellulitis or abscess near joint

›Soft tissue source without true intraarticular infection

05Laboratory Tests/lt43

Blood tests

›Infection and inflammation labs

›Complete blood count for leukocytosis and baseline

›Normal WBC does not exclude

›C reactive protein for inflammation trend

›Useful for response monitoring

›ESR for inflammation

›Less responsive than CRP

›Serum lactate if systemic toxicity

›Sepsis risk stratification

›Microbiology

›Blood cultures x2 if febrile or systemic signs

›Higher yield in bacteremic presentations

›HIV testing if risk factors

›Broader pathogen spectrum

›NAAT for gonorrhea and chlamydia if STI risk

›Extra genital sites as indicated

›Baseline safety labs

›Creatinine and electrolytes for antibiotic dosing

›Renal dosing planning

›Liver enzymes if prolonged therapy anticipated

›Antibiotic toxicity monitoring

Synovial fluid studies

›Core synovial panel

›Gross appearance

›Purulent fluid high concern

›Cell count with differential

›WBC threshold patterns

06Diagnostic Tests/dt45

Scoring Systems

›Pediatric septic hip probability tools

›Kocher criteria

›Fever

›Non weight bearing

›ESR elevation

›Serum WBC elevation

›Modified Kocher

›CRP elevation as additional factor

›Use limitations

›Not definitive

›Lower accuracy in the era of Kingella kingae and changing epidemiology

MRI

›MRI indications

›Suspected adjacent osteomyelitis

›Persistent pain or systemic illness despite aspiration

›Deep joint evaluation

›Hip or sacroiliac infection concern

›Occult abscess

›Poor clinical response

›MRI considerations

›Need for sedation in pediatrics

›Timing impact on source control

›Contrast use

›Abscess delineation

›Interpretation pearls

›Synovial enhancement and marrow edema for osteomyelitis

07Disposition/dispo22

Level of care

›Admission indications

›Suspected or confirmed septic arthritis

›IV antibiotics and drainage planning

›Systemic toxicity or sepsis

›Monitoring and hemodynamic support

›Hip, shoulder, sternoclavicular, or sacroiliac involvement

›Higher complication risk

›Prosthetic joint involvement

›Multidisciplinary management

›ICU indications

›Vasopressor requirement

›Septic shock

›Respiratory failure

›Advanced organ support

›Transfer indications

›Need for orthopedic surgery not available locally

›Time sensitive source control

Discharge considerations

›Discharge rare scenarios

›Low suspicion after aspiration and alternative diagnosis confirmed

›Reliable follow up within 24-48 hours

›Confirmed gonococcal arthritis clinically stable

›Outpatient parenteral therapy only with infectious diseases plan and close follow up

08Treatment/t61

Analgesia and supportive care

›Symptom control

›Acetaminophen PO 1,000 mg q6h PRN

›Maximum 4,000 mg per day

›Ibuprofen PO 400-600 mg q6-8h PRN

›Avoid in CKD or GI bleed risk

›Hydromorphone IV 0.2-0.5 mg q10-15 min PRN severe pain

›Respiratory monitoring

›Sepsis supportive care

›IV crystalloids

›Reassessment after each bolus

›Norepinephrine infusion

›Titrate to MAP at least 65 mmHg

Source control

›Joint drainage strategy

›Repeated needle aspiration

›Suitable for accessible joints with improving clinical course

›Arthroscopic irrigation and debridement

›Common for knee and shoulder

›Open arthrotomy

›Hip infection or failure of less invasive drainage

›Drainage timing

›Same day source control when high suspicion or confirmed

Empiric antibiotics

›Antibiotic timing

›If clinically stable, then aspiration before antibiotics

›Higher synovial culture yield

›If sepsis or shock, then antibiotics immediately

09Special Populations/sp28

Pregnancy

›Pregnancy considerations

›Maternal sepsis risk

›Early obstetric consultation for systemic illness

›Antibiotic safety

›Ceftriaxone generally compatible with pregnancy

›Avoid doxycycline in pregnancy

›Imaging selection

›Ultrasound preferred for effusion evaluation

›MRI without gadolinium when needed

Geriatric

›Older adult considerations

›Atypical presentation

›Less fever and less leukocytosis

›Higher bacteremia risk

›Blood cultures priority

›Renal dosing

›Vancomycin and cefepime adjustments

›Functional baseline

›Mobility and fall risk planning during admission

Pediatrics

›Pediatric considerations

›Hip septic arthritis as emergency

›Early orthopedics involvement

›Weight based dosing

›Vancomycin IV 15 mg/kg q6h to q8h based on age and renal function

›Kingella kingae consideration in toddlers

›Lower fever and lower synovial WBC possible

10Background/b44

Epidemiology

›Disease frequency

›Most often monoarticular

›Knee most common large joint in adults

›Higher risk groups

›Older adults

›Rheumatoid arthritis

›Prosthetic joints

›Common pathogens

›Staphylococcus aureus most common overall

›MRSA prevalence varies by region and risk factors

›Streptococci

›Common in older adults

›Gram negative bacilli

›Higher in elderly and immunocompromised

›Neisseria gonorrhoeae

›Consider in sexually active adolescents and young adults

Pathophysiology

›Infection routes

›Hematogenous seeding

›Bacteremia as common source

›Direct inoculation

›Injection or trauma

›Contiguous spread

›Cellulitis or osteomyelitis adjacent

›Joint damage mechanisms

›Neutrophil driven inflammation

›Protease mediated cartilage destruction

11Patient Discharge Instructions/pdi23

copy discharge instructions

›Discharge plan overview

›Diagnosis summary and uncertainty statement when applicable

›Pending cultures and next steps

›Medication instructions

›Antibiotic schedule if prescribed

›Activity guidance

›Joint rest initially then gradual range of motion as advised

›Return to ED now

›Fever or rigors

›Worsening systemic symptoms

›Increasing joint pain or swelling

›Reduced ability to move joint

›New redness spreading around joint

›Cellulitis progression

›Weakness or numbness distal to joint

›Neurovascular concern

›Vomiting or inability to take medications

›Dehydration risk

›Follow up

›Orthopedics and infectious diseases follow up as arranged

›Appointment within 24-72 hours if outpatient plan

›Primary care follow up

›Risk factor management and prevention

12References/r10

Clinical guidelines and evidence sources

›Guideline sources

›Infectious Diseases Society recommendations for native joint septic arthritis management

›Culture guided therapy and source control emphasis

›American Academy of Orthopaedic Surgeons resources on septic arthritis and joint drainage

›Operative vs aspiration decision frameworks

›Evidence based reviews

›Systematic reviews on synovial WBC thresholds and diagnostic accuracy

›Synovial culture as gold standard

›Literature on pediatric septic hip prediction rules

›Kocher and modified Kocher performance limitations

Evidence & Review

Evidence & Review