Heme

Malaria

/ Brian Gilberti, PGY-3 / 1 Comment
Conference
11/4/2015
Presenter: Edouard Coupet, MD
THE CASE
CC: “Joint pain”
HPI:
  • 23 yo F sent to ED by PMD for “joint pain”
  • Reports polyarthralgias x 1 day
  • Denies CP or SOB
  • Subjective fevers
  • Visited Nigeria 4 weeks prior
  • Did not take malaria ppx
PMH/PSH: HbSS
Medications: Denies
Allergies: NKMA
Physical Exam
Vitals: T 97.1, HR 102, BP 143/73, RR 16, O2 97% on RA
General: NAD
Skin: Jaundiced
HEENT: Scleral icterus
CVS: Tachycardic, regular rhythm, no murmurs
Pulm: CTAB
Extremities: No erythema, no visible e/o trauma, FROM
Studies: 
CBC: Hgb 4.1, Hct 11.3, WBC 20.4, Plt 98, Retic 11.2
Chem: Na 137, K 3.3, CO2 19, Gluc 127, AG 22
LFTs: T. bili 40.1, D. bili 22.8, AST 226, ALT 91, Alk P 247
MALARIA
Background:
  • Most common cause of hemolytic anemia worldwide
  • Most significant disease acquired from travel to tropics
  • P. falciparum most deadly parasite; most common form in Africa, Haiti, New Guinea
  • P. vivax more common in Central America, Indian subcontinent
  • Incubation period = 8-25 days (generally)
  • Mortality = 10-50% if untreated
  • Clinical signs of infection occur during the erythrocytic phase
    • Cyclical symptoms = erythrocytes lyse due to intracellular replication → merozoites released → new erythrocytes infected
  • Parasitized cells lose flexibility → obstruct microcirculation → tissue anoxia of lungs/kidneys/brain
  • Parasite may not be visualized on smear due to sequestration
How do I make the diagnosis?
  • Symptoms
    • Periodic fevers
    • Malaise
    • HA
    • CP
    • Cough
    • Abd pain
    • Arthralgia
    • Diarrhea
  • Paroxysms may not be present in patient’s who received chemoprophylaxis
  • Splenomegaly, abdominal tenderness
  • Anemia, jaundice
  • Coma, altered mental status
  • Blood smear
    • First smear positive in >90% of cases
    • If initial negative, must be repeated BID x 2-3 days for proper exclusion of malaria
    • Determines degree of parasitemia and type (i.e. P. falciparum)
  • Additional lab findings
    • Normocytic anemia
    • Thrombocytopenia
    • ↑ ESR
    • ↑ LDH
    • LFT abnormalities
    • ↑ Cr
    • Hyponatremia
    • Hypoglycemia
    • False positive VDRL
What makes malaria deadly?
  • Hemolysis can lead to severe anemia
  • Sequestration → splenomegaly → splenic rupture
  • Immune mediated glomerulonephritis
  • Cerebral edema (mortality rate >20%)
    • LP: ↑ opening pressure, ↑ protein, mild pleocytosis
  • Noncardiogenic pulmonary edema
  • Renal failure (ATN)
  • Hypoglycemia
  • Adherence of infected cells to endothelium → tissue hypoxia
What is “uncomplicated” P. falciparum and how is it managed in the ED?
  • Uncomplicated:
    • No e/o organ dysfunction
    • Parasitemia <5%
    • Able to tolerate PO
  • Hospitalize:
    • Severe clinical manifestations in non-immune host for P. falciparum or P. knowlesi 
  • Report to state health department
  • For non-pregnant patients (3 day course)
    • Artemether + lumefantrine
    • Artesunate + amodiaquine
    • Artesunate + mefloquine
    • Dihydroartemisinin + piperaquine
    • Artesunate + sulfadoxine–pyrimethamine (SP)
  • For pregnant (1st trimester)
    • Quinine + clindamycin x 7 days
  • Additional considerations
    • Avoid artesunate + SP in HIV/AIDS patients taking co-trimoxazole
    • Avoid artesunate + amodiaquine in HIV/AIDS patients taking efavirenz or zidovudine
And if it’s severe?
  • Severe P. falciparum malaria:
    • GCS < 11
    • Generalized weakness
    • >2 convulsions within 24 hours
    • Acidosis
    • Shock
    • Pulmonary edema
    • Cr > 3 mg/dL or BUN >20
    • T. bili >50 + parasite count >100,000
    • Significant hemorrhage
    • Hgb <7 g/dL, Hct <20%
    • Glucose <40 mg/dL
    • Hyperparasitemia >10%
  • Do not delay treatment in the unstable patient if strong suspicion for malaria as initial smear may be falsely negative
  • Treatment (IV for ≥24 hours then 3 days PO course)
    • Artesunate (IV)
      • Clears malaria faster than quinine
      • Distributed only through CDC
    • Quinidine (IV) also appropriate choice; more available in US
What do I do for the associated complications?
  • AMS
    • Due to cerebral sequestration of infected erythrocytes
    • Requires LP to rule out meningitis as cause
    • Seizures commonly reported in children and to be treated with benzodiazepines
    • Steroids of no benefit
  • Anemia
    • Transfuse at Hgb <4 g/dL or <6 g/dL if AMS, acidosis, shock, or parasitemia >20%
    • There is no evidence to support exchange transfusions as an adjunct and is not recommended by CDC or WHO
  • Respiratory distress
    • Patient may develop noncardiogenic pulmonary edema (similar to ARDS)
    • Supplemental O2 to be administered
    • May require mechanical ventilation

REFERENCES

Bremen, Joel. “Clinical manifestations of malaria.” Up To Date. http://www.uptodate.com, 5 Nov. 2015. Web. 30 Nov. 2015. http://www.uptodate.com/contents/clinical-manifestations-of-malaria

Kyriacou DN, Spira AM, Talan DA, Mabey DC. Emergency department presentation and misdiagnosis of imported falciparum malaria. Ann Emerg Med. 1996;27(6):696-9.

Taylor, Terrie. “Treatment of severe falciparum malaria.” Up To Date. http://www.uptodate.com, 29 Oct. 2015. Web. 30 Nov. 2015. http://www.uptodate.com/contents/treatment-of-severe-falciparum-malaria

Tintinalli, Judith E., and J. Stephan. Stapczynski. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 7th ed. New York: McGraw-Hill, 2011.

World Health Organization. Guidelines for the treatment of malaria, 3rd ed, WHO, Geneva 2015. http://www.who.int/malaria/publications/atoz/9789241549127/en/