EDWARD FISHER, MD PGY-3JUNE 11 , 2014

Morning Report

5 yo boy with cough and fever

Presents with cough and fever x5 days, up to 103.5 F

Dx with viral illness at PCP 2 days prior to admission

Intermittent emesis, poor PO intake

Brought to PCH ED for worsening sx

5 yo boy with cough and fever

PMH: Healthy, no surgeriesNo meds, NKDAImms: Up to dateFH: Older brother died at home at 15

months of pneumonia/strep pneumo bacteremia (was fully immunized, prior to PCV 13). Lots of pneumonia on paternal side?

SH: Lives with parents, older brother, no tobacco exposure

5 yo boy with cough and fever

T 37.3, HR 163, RR 36, 94% on RAGen: pale but well-appearing, tachypneic,

NADHEENT: normalCV: Tachycardic, no murmurs, good pulsesResp: Diminished breath sounds on L with

crackles. No retractionsAbd: soft, NT/ND, normal BSSkin: normalNeuro: normal

In the ED…

Due to history of poor PO, bolused 40 mL/kgWBC 10.6 (22% bands), Hct 36.6, Plts 164Blood cx sentCXR: LLL pneumonia with effusionNot hypoxicAdmit to RTU, IV ampicillin

In the RTU…

Worsening work of breathing, tachypnea, increasing effusion on CXR

As he is being transferred, blood culture turns positive @16 hrs, DNA for S pneumo detected

Ampicillin --> ceftriaxone

On the floor…

Worsening effusion --> chest tube placement

Mild hyponatremia (SIADH?)

Not hypoxic

Subsequent blood cultures negative

Overnight…

Called to evaluate pt ~2300

Worsened tachycardia (130s --> 170s)

Looks more pale/yellow, more swollen

Nurse is concerned he looks bad, and wants to call a rapid response

Overnight…

T 37.6, HR 167, RR 40, BP 107/62, 88% on RA

Gen: pale/yellow/greenish, not wanting to interact

HEENT: very pale conjunctivaCV: Tachycardic, no murmurs, good pulses,

cap refill hard to elicitResp: Diminished breath sounds on L with

crackles. No retractions. Chest tube in place

Abd: soft, NT/ND, normal BS, no HSMSkin: normalNeuro: normal

Differential diagnosis

Heme Blood loss (Chest tube,

hemothorax, abdomen, GI bleed)

Hemolysis Anemia of

inflammatory state DIC TTP

Rheum Vasculitis

Renal HUS

Labs

WBC 17.6 (23% bands), Hgb 3.9, Hct 11.1, Plts 46

Smear 2+ schistocytes

Na 136, K 4.7, Cl 113, bicarb 17, BUN 33, creat 0.71, gluc 121, alb 2.1, bili 2.1, ALT 26, AST 213

PT/INR 15.4/1.2, PTT 48, fibrinogen 633

D-dimer 4467

Hemolytic-Uremic Syndrome

Microangiopathic hemolytic anemia

Thrombocytopenia

Acute kidney injury

HUS Classifications

Diarrhea positive/negative

Primary (complement gene mutations, antibodies to complement factor B)

Secondary (usually infectious)

Epidemiology

STEC: 90% of HUS cases

Pneumococcus: ~5% (40% of non-STEC cases)

HUS in ~0.5% of pneumococcal infections

Pathogenesis (?)

Certain serotypes of strep pneumo expose Thomsen-Friedenreich (T) antigen (serotype 19A)

Preformed host IgM bind T antigen

Cascade of events lead to HUS

Alternative complement-mediated pathway?

Management

Treat underlying pneumococcal infection - empirically if necessary Consider rates of resistance

HUS therapy largely supportive RBCs and platelets STOP nephrotoxic drugs Nephrology involvement (dialysis?)

Avoid FFP, plasmapheresis (theoretical)

Risk Factors and Outcome

Generally more severe than STEC HUS Mortality higher (5-10% vs 12%) More likely to require dialysis (67-80%) Need more transfusions (PRBs and plts)

Death usually due to infection Biggest risk factor: meningitis (88% of deaths in the

largest review)~10% evolve to ESRD requiring dialysis

References

Banerjee R et al. Streptococcus pneumoniae-associated hemolytic uremic syndrome among children in North America. Pediatr Infect Dis J 30:736, 2011

Copelovitch L, Kaplan BS. Streptococcus pneumoniae-associated hemolytic uremic syndrome. Pediatr Nephrol 23:1951-56, 2008

Copelovitch L, Kaplan BS. Streptococcus pneumoniae-associated hemolytic uremic syndrome: classification and the emergence of serotype 19A. Pediatrics 125:174-182, 2010

Geary DF. Hemolytic uremic syndrome and Streptococcus pneumoniae: improving our understanding. J Pediatr 151:113, 2007

Spinale JM et al. Update on Streptococcus pneumoniae-associated hemolytic uremic syndrome. Curr Opin Pediatr 25:203-8, 2013