CASE 1

Septic Shock - ESBL E. coli Urosepsis

Patient: M.J., 68 y/o F DOS: 01/18/2026 Setting: ICU
⚠️ SEPSIS ALERT — Hour-1 Bundle initiated. Lactate 4.2. Vasopressors required.
S
SUBJECTIVE
Chief Complaint
"My mother is confused with high fever" (per daughter)
HPI

68 y/o nursing home resident with 2 days decreased intake, lethargy, fevers. Today minimally responsive, T 102.8°F. Foley catheter x3 weeks for neurogenic bladder. Foul-smelling urine x3 days.

PMH
T2DM, HTN, CVA with hemiparesis, Neurogenic bladder, Recurrent UTIs
Allergies
Penicillin (anaphylaxis), Sulfa (rash)
O
OBJECTIVE
Vitals
BP
78/52
HR
118
Temp
102.8°F
SpO2
94% 2L
Exam

General: Ill-appearing, lethargic, oriented to self only

Abd: Suprapubic/CVA tenderness, cloudy Foley urine

Labs
WBC18.4 K (12% bands) ↑
Lactate4.2 mmol/L ↑
Creatinine2.1 (baseline 1.0) ↑
Procalcitonin8.6 ng/mL ↑
Blood Cx2/2 GNR → ESBL E. coli
🦠 Pathogen
ESBL E. coli — Susceptible: Meropenem, Amikacin. Resistant: Ceftriaxone, Cipro, TMP-SMX
A
ASSESSMENT
1. Septic Shock - ESBL E. coli Urosepsis A41.51
  • CAUTI T83.511A
  • AKI Stage II N17.9
  • Sepsis-associated encephalopathy G93.41
qSOFA
3/3
RR≥22, AMS, SBP≤100 — High mortality risk
P
PLAN
💉 Antimicrobials
  • Meropenem 1g IV q8h (ESBL coverage)
  • D/C Ceftriaxone (resistant)
  • Duration: 10-14 days bacteremia
💊 Rationale
ESBL requires carbapenem. PCN allergy (anaphylaxis) has <1% carbapenem cross-reactivity.
🚨 Sepsis Bundle
  • 30 mL/kg crystalloid bolus
  • Norepinephrine for MAP >65
  • Repeat lactate q6h
🔬 Source Control
  • Replace Foley catheter
  • Renal US (no obstruction)
  • Repeat BCx in 48-72h
R.S., MD, FIDSA
ID Specialist
01/18/2026
📚 Educational Pearl — ESBL Urosepsis
  • ESBL risk: Recent abx, healthcare exposure, recurrent UTI, catheter
  • Hour-1 Bundle: Lactate, cultures, broad abx, 30mL/kg fluid, vasopressors if needed
  • ESBL treatment: Carbapenems are drugs of choice
💰 Billing
E/M
99223
ICD-10
A41.51
CASE 2

Severe Community-Acquired Pneumonia (S. pneumoniae)

Patient: T.W., 58 y/o M DOS: 01/19/2026 Setting: Medical Floor
S
SUBJECTIVE
Chief Complaint
"Terrible cough with rust-colored sputum, can barely breathe."
HPI

58 y/o male with 4 days productive cough (rust-colored), fever 103°F, dyspnea progressing to rest, right pleuritic chest pain. Rigors, night sweats, fatigue. No recent travel/hospitalizations.

PMH
T2DM (A1c 8.2%), COPD (FEV1 62%), HTN, Former smoker 30py
Immunizations
No pneumococcal vaccine, flu vaccine 3mo ago
O
OBJECTIVE
Vitals
BP
108/68
HR
102
RR
26
Temp
102.4°F
SpO2
89% RA
Exam

Lungs: Decreased BS RLL, bronchial breath sounds, egophony, crackles RML/RLL

Labs/Imaging
WBC19.2 K (8% bands) ↑
Procalcitonin2.4 ng/mL ↑
CXRRML/RLL consolidation
Sputum GSGPC in pairs (lancet)
Pneumo UATPOSITIVE
🦠 Pathogen
Streptococcus pneumoniae — UAT+, GPC pairs on sputum
A
ASSESSMENT
1. Severe CAP (S. pneumoniae) J13
  • Acute hypoxic respiratory failure J96.01
  • COPD exacerbation J44.1
CURB-65
2
BUN>19, RR≥30 — Inpatient treatment
P
PLAN
💉 Antimicrobials
  • Ceftriaxone 1g IV q24h + Azithromycin 500mg IV daily
  • Duration: Min 5 days, afebrile ≥48h
💊 IDSA/ATS CAP
Severe CAP: β-lactam + macrolide OR respiratory FQ. Macrolide adds atypical coverage + immunomodulation.
🫁 Respiratory
  • O2 to SpO2 ≥92%
  • Nebs (albuterol/ipratropium)
  • Incentive spirometry
🛡️ Prevention
  • PCV20 before discharge
  • Smoking cessation
A.L., MD
ID Specialist
01/19/2026
📚 Educational Pearl — CAP
  • Top pathogens: S. pneumoniae (#1), H. influenzae, Atypicals
  • CURB-65: Confusion, Urea>19, RR≥30, BP<90/60, Age≥65
  • Duration: Min 5 days; afebrile ≥48h + ≤1 instability sign
💰 Billing
E/M
99223
ICD-10
J13
CASE 3

Purulent Cellulitis with MRSA Abscess

Patient: K.D., 42 y/o M DOS: 01/20/2026 Setting: ED → Medical Floor
S
SUBJECTIVE
Chief Complaint
"Right leg swollen, red, painful bump oozing pus."
HPI

42 y/o male, 5 days progressive R leg swelling/erythema/warmth. 4cm fluctuant nodule draining pus x2 days. Fevers 101°F, difficulty bearing weight. H/o MRSA abscess 2 years ago.

PMH
Prior MRSA SSTI, T2DM (A1c 7.8%), Obesity BMI 34
SH
Construction worker, no IVDU
O
OBJECTIVE
Vitals
BP
132/78
HR
94
Temp
101.2°F
Exam

RLE: 15x10cm erythema, warmth, induration. Central 4cm fluctuant nodule with purulent drainage. No crepitus, no necrosis. Tender R inguinal LN.

Labs
WBC14.8 K ↑
CRP86 mg/L ↑
Wound CxMRSA (CA-MRSA, PVL+)
🦠 Pathogen
MRSA — Susceptible: Vanc, TMP-SMX, Doxy, Clinda (D-test neg). Resistant: Oxacillin
A
ASSESSMENT
1. Purulent Cellulitis with MRSA Abscess L02.416
  • MRSA infection A49.02
  • T2DM E11.9
SSTI Classification
Purulent — Moderate
Abscess + systemic symptoms. I&D + antibiotics.
P
PLAN
🔪 Source Control
  • Bedside I&D — 15cc purulent drainage
  • Wound packed, daily repacking
💉 Antimicrobials
  • Vancomycin 1.5g IV q12h (trough 10-15)
  • Transition to TMP-SMX DS 2 tabs BID PO
  • Duration: 7-10 days total
💊 IDSA SSTI
Purulent SSTI: I&D is primary. Add systemic abx if: fever, multiple lesions, immunocompromised, failed I&D.
🛡️ Decolonization
  • Mupirocin nasal BID x5d
  • Chlorhexidine washes x5d
J.P., MD
ID Specialist
01/20/2026
📚 Educational Pearl — MRSA SSTI
  • Purulent vs Non-purulent: Purulent = abscess (Staph); Non-purulent = diffuse (Strep)
  • CA-MRSA: PVL-positive, furuncles/abscesses
  • I&D is definitive: For uncomplicated <2cm abscess, I&D alone may suffice
  • Nec fasc red flags: Pain out of proportion, rapid spread, crepitus, necrosis
💰 Billing
E/M
99222
Procedure
10060 (I&D)
CASE 4

C. difficile Colitis — Severe, First Recurrence

Patient: P.M., 74 y/o F DOS: 01/21/2026 Setting: Medical Floor
S
SUBJECTIVE
Chief Complaint
"The diarrhea is back — 10 watery BMs today with cramping."
HPI

74 y/o female with CDI 6 weeks ago (completed 10-day oral vancomycin). Symptom-free 3 weeks, then 5 days ago developed watery diarrhea 8-10 BMs/day. Was on clindamycin 2 weeks ago for dental abscess.

PMH
Prior CDI (6wks), HTN, CKD Stage 3a, Recent dental infection
O
OBJECTIVE
Vitals
BP
118/72
HR
92
Temp
100.8°F
Exam

Abd: Soft, diffusely tender LLQ>RLQ, hyperactive BS, no guarding

Labs
WBC16.2 K ↑
Creatinine1.8 (baseline 1.4) ↑
Albumin2.8 g/dL ↓
C. diff PCRPOSITIVE
C. diff ToxinPOSITIVE
CT AbdColonic wall thickening
A
ASSESSMENT
1. C. difficile Colitis, First Recurrence, Severe A04.72CONTACT
  • AKI on CKD N17.9
  • Dehydration E86.0
CDI Severity
SEVERE
WBC ≥15K AND/OR Cr >1.5x baseline
P
PLAN
💉 Antimicrobials
  • Fidaxomicin 200mg PO BID x10 days (preferred 1st recurrence)
  • Alt: Vanc taper (125mg QID x14d → taper)
💊 IDSA/SHEA 2021
First recurrence: Fidaxomicin preferred (~13% vs ~27% recurrence with vanc).
🦠 Adjunctive
  • Consider Bezlotoxumab (monoclonal Ab) — high recurrence risk patient
💧 Supportive
  • IVF resuscitation
  • Avoid loperamide
  • Contact isolation
📅 Follow-up
  • If ≥2 recurrences: consider FMT
  • No repeat testing after tx (PCR stays+)
L.C., MD, FIDSA
ID Specialist
01/21/2026
📚 Educational Pearl — C. difficile
  • Recurrence risk: 20-30% after 1st; 40-60% after ≥2
  • Severity: Non-severe (WBC<15, Cr<1.5x), Severe (WBC≥15 OR Cr≥1.5x), Fulminant (shock, ileus, megacolon)
  • Don't test: Asymptomatic or post-treatment
  • FMT: After ≥2 recurrences despite appropriate therapy
💰 Billing
E/M
99223
ICD-10
A04.72
CASE 5

Infective Endocarditis — Native Tricuspid, MSSA

Patient: D.R., 52 y/o M DOS: 01/22/2026 Setting: ICU → Step-down
S
SUBJECTIVE
Chief Complaint
"Fevers and chills for 2 weeks that won't go away, now short of breath."
HPI

52 y/o male with h/o IVDU (in recovery, last use 3 weeks ago) presents with 2 weeks fevers to 103°F, night sweats, rigors, fatigue, 10-lb weight loss. Progressive dyspnea. Painful red spots on fingertips x5 days.

PMH
IVDU (heroin, in recovery), HCV (SVR), Depression
Meds
Buprenorphine-naloxone 8-2mg SL daily
O
OBJECTIVE
Vitals
BP
108/62
HR
104
Temp
102.6°F
SpO2
92% RA
Exam

CV: III/VI holosystolic murmur LLSB (new), elevated JVP

Skin: Osler nodes (3) on fingertips, track marks

Lungs: Bibasilar crackles

Labs/Imaging
WBC17.8 K ↑
Hgb9.2 g/dL ↓
Blood Cx 4/4MSSA
TTE1.8cm vegetation TV, mod TR
CT ChestBilateral pulm nodules (septic emboli)
🦠 Pathogen
MSSA — Susceptible: Oxacillin (MIC 0.5), Cefazolin, Vanc. 4/4 bottles+.
A
ASSESSMENT
1. Infective Endocarditis, Native TV, MSSA I33.0
  • Septic pulmonary emboli I26.99
  • S. aureus bacteremia A41.01
  • Acute HF (TR-related) I50.9
Modified Duke Criteria
DEFINITE IE
2 Major (BCx, vegetation) + 3 Minor (fever, IVDU, emboli)
P
PLAN
💉 Antimicrobials
  • Nafcillin 2g IV q4h (or Cefazolin 2g IV q8h)
  • Duration: 6 weeks (native valve S. aureus IE)
💊 AHA/IDSA IE
MSSA IE: β-lactam preferred. Vancomycin only if true allergy (inferior outcomes).
❤️ Surgery Eval
  • CT Surgery consult — large vegetation, HF symptoms
  • Indications: veg >2cm, persistent bacteremia, severe TR/HF
📊 Monitoring
  • Daily BCx until negative
  • Repeat TTE in 1-2 weeks
🛡️ Addiction Medicine
  • Continue buprenorphine (do NOT stop)
  • Addiction medicine consult
M.K., MD, FIDSA
ID Specialist
01/22/2026
📚 Educational Pearl — Endocarditis
  • Duke Major: Typical organism ≥2 BCx, vegetation/abscess on echo, new regurgitation
  • Right-sided IE: IVDU-associated, tricuspid, septic pulm emboli, better prognosis
  • S. aureus IE mortality: 20-40%
  • MSSA vs MRSA: Always prefer β-lactam for MSSA
💰 Billing
E/M
99223
ICD-10
I33.0
CASE 6

Acute Bacterial Meningitis (S. pneumoniae)

Patient: E.S., 28 y/o F DOS: 01/23/2026 Setting: Neuro ICU
⚠️ MENINGITIS ALERT — Droplet precautions. Empiric abx + dexamethasone given immediately.
S
SUBJECTIVE
Chief Complaint
"Worst headache of my life, neck so stiff, light hurts my eyes."
HPI

28 y/o female with 2 days severe headache 10/10, fever, neck stiffness, photophobia. Unable to flex neck. Nausea, 3x vomiting. Had URI 1 week ago.

PMH
Asthma (mild)
Immunizations
MenACWY (college), no PCV
O
OBJECTIVE
Vitals
BP
142/88
HR
118
Temp
103.4°F
Exam

General: Toxic, photophobic, GCS 14

Neck: Severe nuchal rigidity, Kernig +, Brudzinski +

Neuro: No focal deficits, no papilledema

Labs/CSF
WBC (blood)18.6 K ↑
Opening Pressure32 cmH2O ↑
CSF WBC2,400 (92% PMN) ↑
CSF Protein285 mg/dL ↑
CSF Glucose18 (serum 112) ↓
CSF Gram StainGPC pairs (lancet)
CSF PCRS. pneumoniae +
🦠 Pathogen
Streptococcus pneumoniae — CSF Gram stain + PCR confirmed
A
ASSESSMENT
1. Acute Bacterial Meningitis (S. pneumoniae) G00.1DROPLET
  • Elevated ICP G93.2
  • Systemic inflammatory response R65.10
CSF Profile
BACTERIAL
High WBC (PMN), High protein, LOW glucose, GPC on Gram stain
P
PLAN
💉 Antimicrobials (Given in ED)
  • Ceftriaxone 2g IV q12h (meningitic dosing)
  • Vancomycin 20mg/kg IV q8-12h (until susceptibilities)
  • Dexamethasone 0.15mg/kg IV q6h x4 days
  • Duration: 10-14 days for pneumococcal
💊 IDSA Meningitis
Empiric: CTX + Vanc. Dexamethasone BEFORE/WITH abx — reduces mortality/hearing loss.
🧠 Neuro-ICU
  • HOB 30°
  • Seizure precautions
  • Monitor for cerebral edema
  • Repeat LP if no improvement 48-72h
📊 Monitoring
  • Q1h neuro checks
  • Vanc trough 15-20
  • Audiology before discharge
🛡️ Public Health
  • Droplet precautions x24h of therapy
  • NO chemoprophylaxis for S. pneumo contacts
  • PCV20 after recovery
S.T., MD, FIDSA
ID Specialist
01/23/2026 04:45
📚 Educational Pearl — Bacterial Meningitis
  • Classic triad: Fever, headache, nuchal rigidity — only 44% have all 3
  • CT before LP: If immunocompromised, CNS disease, seizure, papilledema, AMS, focal deficit
  • CSF bacterial: WBC>1000 (PMN), protein>200, glucose<40 (ratio<0.4)
  • Dexamethasone: Give 15-20min BEFORE/WITH abx. No benefit if given after.
  • Chemoprophylaxis: N. meningitidis contacts — NOT S. pneumoniae
💰 Billing
E/M
99223
ICD-10
G00.1