Rosen & Barkin's 5-Minute Emergency Medicine Consult (328 page)

• Ribavirin (WHO 2006 recommendations):
  
  • IV loading dose of 33 mg/kg followed by 16 mg/kg q6h for 4 days, then 8 mg/kg q8h for 3 days
    
  • Prophylactic 500 mg by mouth q6h for 7 days
    
• Vaccines:
  
  • Yellow fever is widely available.
    
  • South American hemorrhagic fever, Rift Valley fever, Hantavirus, Dengue, and Ebola/Marburg are under development.
    
• Other medications under investigation:
  
  • Nucleoside analog inhibitors of
    S
    -adenosylhomocysteine hydrolase inhibit Ebola replication in mice.
    
  • Zidampidine—a derivative of AZT—increases survival of mice infected with Lassa virus
    

• Hemodynamic support
  
• Ribavirin
  
• Antimalarials
  

Contact the CDC about experimental vaccines and antivirals for postexposure prophylaxis (770) 488-7100 or (800) 311-3435 for all suspected cases.

FOLLOW-UP

Suspected cases of VHF, particularly those with suspected multisystem involvement/compromise

• Isolation precautions
  
• ICU for signs of shock or multiorgan system failure
  

None—if you suspect VHF,
the patient needs to be isolated and the CDC notified

Consider experimental postexposure prophylaxis for staff and patient contacts that may include antivirals and vaccines. Coordinate with the CDC at (770) 488-7100 or (800) 311-3435.

• EXTREME
  caution with volume resuscitation
  
• Hemoconcentration and pulmonary involvement are
  RED FLAGS
  
• Consider hemorrhagic viruses in your differential diagnosis when caring for a sick patient returning from endemic regions of the world
  
• Employ universal precautions and isolation to minimize the spread of the disease
  
• Contact the CDC at (770) 488-7100 or (800) 311-3435 for all suspected cases.
  

• Jeffs B. A clinical guide to viral hemorrhagic fevers: Ebola, Marburg and Lassa.
  Trop Doct
  . 2006;36:1–4.
  
• Mahanty S, Bray M. Pathogenesis of filoviral haemorrhagic fevers.
  Lancet Infect Dis
  . 2004;4:487–498.
  
• Pigott DC. Hemorrhagic fever viruses.
  Crit Care Clin
  . 2005;21:765–783.
  
• Rhee DK, Clark RP, Blair RJ, et al. Clinical Problem-solving. Breathtaking journey.
  N Engl J Med
  . 2012;367(5):452–457.
  
• Simmons CP, Farrar JJ, Nguyen vV, et al.
  Dengue. N Engl J Med.
  2012;366(15):1423–1432.
  
• Staples JE, Monath TP. Yellow fever: 100 years of discovery.
  JAMA
  . 2008;300(8):960–962.
  
• Whitehouse CA. Crimean-Congo hemorrhagic fever.
  Antiviral Res.
  2004;64(3):145–160.
  

See Also (Topic, Algorithm, Electronic Media Element)

• Dengue Fever
  
• Disseminated Intravascular Coagulation
  
• Hemorrhagic Shock
  
• Malaria
  
• Meningococcemia
  

CODES

• 065.4 Mosquito-borne hemorrhagic fever
  
• 065.9 Arthropod-borne hemorrhagic fever, unspecified
  
• 078.89 Other specified diseases due to viruses
  

BASICS

• Loss of effective circulating blood volume resulting in inadequate perfusion
  
• Blood loss exceeds ability to compensate and tissue and organ perfusion decrease. At the tissue level, hypoperfusion leads to inadequate oxygenation, anaerobic metabolism, cell death
  
• Hemorrhagic shock is the most common cause of shock from injury
  
• Compensated shock:
  
  • Patient’s physiologic reserve prevents significant alteration in vital signs
    
• Decompensated shock:
  
  • Loss of circulating volume overcomes patient’s physiologic reserve, resulting in signification alteration in vital signs.
    
• Blood loss estimate:
  
  • Total blood volume ∼7% of ideal body weight (4,900 mL in 70 kg adult) or 70 mL/kg
    
  • Multiply 70 mL/kg × body weight (kg) × percentage loss as determined by class of hemorrhage.
    

• Trauma—penetrating and blunt:
  
  • Abdominal:
    
    • Splenic injury
      
    • Liver injury
      
  • Chest:
    
    • Hemothorax
      
    • Aorta or great vessel injury
      
  • Pelvis:
    
    • Pelvic fracture with vascular injury
      
• Vascular malformations:
  
  • May lead to thoracic, intraperitoneal, or retroperitoneal bleeding
    
  • Aneurysms:
    
    • Abdominal aortic aneurysm most common
      
    • Mycotic aneurysm secondary to endocarditis
      
  • Aortogastric fistula
    
  • Arteriovenous malformations
    
• Abortion: Complete, partial, or inevitable
  
• Ectopic pregnancy
  
• Epistaxis
  
• Fractures (especially pelvis and long bones)
  
• GI bleeding
  
• Hemoptysis
  
• Malignancies
  
• Mallory–Weiss tear
  
• Placenta previa
  
• Postpartum hemorrhage
  
• Retroperitoneal bleeds
  
• Splenic rupture
  
• Vascular injuries
  

DIAGNOSIS

• Class I hemorrhage: Loss of up to 15% of blood volume (up to 750 mL in 70 kg adult):
  
  • HR <100
    
  • SBP normal
    
  • Respiratory rate (RR) 14–20
    
  • Increased or normal pulse pressure
    
  • Slight anxiety
    
• Class II hemorrhage: Loss of 15–30% of blood volume (750–1,500 mL):
  
  • Tachycardia: HR >100
    
  • SBP normal, or minimally decreased
    
  • Tachypnea: RR 20–30
    
  • Narrowed pulse pressure
    
  • Mild anxiety
    
  • Small decrease in urine output
    
• Class III hemorrhage: Loss of 30–40% of blood volume (1,500–2,000 mL):
  
  • Marked tachycardia: HR >120
    
  • Hypotension: SBP decreased
    
  • Marked tachypnea: RR 30–40
    
  • Marked narrowing of pulse pressure
    
  • Significant change in mental status: Confusion
    
  • Delayed capillary refill
    
  • Marked decrease in urine output
    
• Class IV hemorrhage: Loss of >40% of blood volume (>2,000 mL):
  
  • HR >140
    
  • Marked hypotension: SBP decreased
    
  • RR >35
    
  • Very narrow pulse pressure
    
  • Depressed mental status: Confusion, lethargy, loss of consciousness
    
  • Negligible urine output
    
  • Cold and pale skin
    

• Children often have greater physiologic reserve than adults and can preserve normal vital signs longer
  
• Systemic responses to blood loss in the pediatric patient include:
  
  • Volume loss <25%: Weak, thready pulse and tachycardia; lethargy, irritability, and confusion; cool, clammy skin; decreased urine output/increased urine specific gravity
    
  • Volume loss 25–40%: Tachycardia; marked change in consciousness; dulled response to pain; cyanotic, cold extremities with decreased capillary refill; minimal urine output
    
  • Volume loss >40%: Hypotension, tachycardia, or bradycardia; comatose; pale, cold skin; no urine output
    

Physiologic maternal hypervolemia requires greater blood loss to manifest maternal perfusion abnormalities which may result in decreased fetal perfusion.