Rosen & Barkin's 5-Minute Emergency Medicine Consult (346 page)

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Authors: Jeffrey J. Schaider,Adam Z. Barkin,Roger M. Barkin,Philip Shayne,Richard E. Wolfe,Stephen R. Hayden,Peter Rosen

Tags: #Medical, #Emergency Medicine

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  • AMS:
    • Without presence of HAPE or HACE, the physical exam will often be normal:
      • Mild stages of AMS are often misdiagnosed as viral syndromes or hangovers from alcohol ingestions
  • HAPE:
    • Tachypnea
    • Rales
    • Cyanosis
    • Fever may be present.
    • Severe respiratory distress and death may occur.
  • HACE:
    • Ataxia
    • Papilledema, retinal hemorrhages
    • Altered mental status/global encephalopathy:
      • Focal neurologic deficit less common
      • Seizure (rare)
      • Coma
      • Has been described as “end-stage” AMS
ESSENTIAL WORKUP
  • Clinical diagnosis in the setting of recent altitude gain
  • AMS:
    • Diagnosis made with history of headache + at least 1 of the following:
      • Nausea/vomiting
      • Lassitude/fatigue
      • Dizziness
      • Insomnia
    • No diagnostic lab or imaging studies
  • HAPE:
    • Dyspnea on exertion—universal finding at altitude
    • Dyspnea at rest—symptom of HAPE, worse at night
    • Rales, cyanosis, or cough support diagnosis.
    • Tachycardia, tachypnea often correlate with severity.
  • HACE:
    • Cerebellar ataxia with or without other symptoms of AMS
    • Papilledema, retinal hemorrhages are associated findings.
DIAGNOSIS TESTS & NTERPRETATION
Lab

Arterial blood gas (ABG) for HAPE:

  • Reveals hypoxemia (pO
    2
    30–50) and respiratory alkalosis,
    not
    acidosis
Imaging
  • CXR in HAPE:
    • Reveals patchy alveolar infiltrates with areas of clearing between patches
    • Unilateral or bilateral infiltrates (right mid-lung field being most common)
    • Cardiomegaly, “batwing” distribution of infiltrates, and Kerley B lines (typical of cardiogenic pulmonary edema)—are generally absent in HAPE
  • CT and MRI scans in HACE:
    • Vasogenic edema of white matter
Diagnostic Procedures/Surgery

ECG in HAPE:

  • Tachycardia
  • Evidence of right-heart strain
DIFFERENTIAL DIAGNOSIS
  • AMS:
    • Alcohol hangover
    • Carbon monoxide poisoning
    • Encephalitis
    • Exhaustion
    • Meningitis
    • Viral syndrome
  • HAPE:
    • High-altitude bronchitis and pharyngitis
    • Pneumonia
    • Pulmonary embolism:
      • More rapid onset
      • Pleuritic chest pain
  • HACE:
    • Cerebrovascular accidents/transient ischemic attacks:
      • Focal neurologic signs suggest vascular lesion.
TREATMENT
PRE HOSPITAL
  • Severe cases require immediate evacuation to lower altitude.
  • Do not proceed to higher altitude in the presence of symptoms.
  • Oxygen delivery or simulated descent in portable hyperbaric chamber (Gamow bag) can be lifesaving temporary measure making self-rescue possible.
INITIAL STABILIZATION/THERAPY
  • HAPE and HACE:
    • ABCs:
      • Endotracheal intubation for impending respiratory failure or airway protection
    • Establish IV access.
    • Supplemental oxygen and monitoring
    • CPAP for HAPE
ED TREATMENT/PROCEDURES
  • AMS:
    • Mild cases usually self-limited:
      • Symptomatic treatment
      • Halt ascent until symptoms resolve
    • Acetazolamide for moderate to severe symptoms
    • Ibuprofen or acetaminophen for headache
    • Promethazine or ondansetron for nausea
    • Supplemental oxygen in severe cases
    • Descent for severe or persistent symptoms
    • Acetazolamide for AMS prophylaxis:
      • In high-risk individual with planned rapid ascent
  • HAPE:
    • Immediate descent for moderate/severe symptoms
    • Mild cases may be managed without descent if:
      • Adequate oxygen supplies available
      • Serial medical exam possible
      • Immediate descent for any deterioration in clinical status
    • Bed rest to avoid exercise-induced pulmonary HTN
    • Supplemental oxygen:
      • High flow rates (6–8 L/min) until improvement, then continue with lower flow rates
    • Nifedipine when other interventions are unavailable
    • β-agonist inhalers may be helpful.
    • Hyperbaric therapy is available and immediate descent is not possible
  • HACE:
    • Immediate evacuation to lower altitude
    • Oxygen
    • Dexamethasone
    • Bed rest with elevation of head at 30°, and in severe cases, aggressive management of elevated intracranial pressure
MEDICATION
  • Acetazolamide:
    • AMS treatment: 250–500 mg (peds: 5 mg/kg) PO BID
    • AMS prophylaxis: 250 mg PO BID (peds: 5 mg/kg) PO BID; start 24 hr before ascent
  • Dexamethasone: 8 mg IV, then 4 mg PO/IV QID
  • Ibuprofen: 800 mg (peds: 5–10 mg/kg) PO TID
  • Nifedipine: 10 mg PO, then 30 mg sustained release (SR) PO QD
  • Promethazine: 12.5–25 mg (peds: 0.25–1 mg/kg) PO/PR (per rectum)/IM q4–6h
First Line
  • Acetazolamide (AMS)
  • Nifedipine (HAPE)
Second Line

Dexamethasone

The use of multiple medications in treating high-altitude illness is not supported by the current literature

FOLLOW-UP
DISPOSITION

Descent to a lower altitude mandatory in severe cases

Admission Criteria
  • Persistent symptoms after observation in lower-altitude ED require admission.
  • HAPE
  • HACE
Discharge Criteria

Once clinical improvement seen and oxygen saturation >95% on room air at sea level or appropriate normal saturation at higher altitudes

Issues for Referral

Offer prophylactic therapy for future ascents in patients with recurrent AMS (acetazolamide) or HAPE (nifedipine).

PEARLS AND PITFALLS
  • The symptoms of high-altitude illness can resemble mild viral syndromes.
  • Failure to consider high-altitude illness is a common pitfall.
  • When managing altitude illness, once symptoms have developed and until they resolve, further ascent is contraindicated.
  • Ataxia and dyspnea at rest are potentially early indicators of HACE and HAPE, respectively.
  • Hyperbaric oxygen and adjunctive medications should be considered when descent is not possible.
ADDITIONAL READING
  • Basnyat B, Murdoch DR. High altitude illness.
    Lancet.
    2003;361:1967–1974.
  • Eide RP, Asplund CA. Altitiude illness: Update on prevention and treatment.
    Curr Sports Med Rep.
    2012;11:124–130.
  • Hackett PH, Roach RC. High-altitude illness.
    N Engl J Med.
    2001;345:107–114.
  • Jones BE, Stokes S, McKenzie S, et al. Management of high altitude pulmonary edema in the Himalaya: A review of 56 cases presenting at Pheriche medical aid post (4240 m).
    Wilderness Environ Med
    . 2013;24(1):32–36.
  • Lipman GS, Kanaan NC, Holck PS, et al. Ibuprofen prevents altitude illness: A randomized controlled trial for prevention of altitude illness with nonsteroidal anti-inflammatories.
    Ann Emerg Med.
    2012;59:484–490.
  • Yaron M, Honigman B. High altitude medicine. In: Marx JA, ed.
    Rosen’s Emergency Medicine: Concepts and Clinical Practice
    . 7th ed. Philadelphia, PA: Mosby; 2010:1917–1928.
CODES
ICD9

993.2 Other and unspecified effects of high altitude

ICD10
  • T70.20XA Unspecified effects of high altitude, initial encounter
  • T70.29XA Other effects of high altitude, initial encounter
HIP INJURY
Siobhan Gray
BASICS
DESCRIPTION
  • Hip injury includes hip fractures and dislocations of the proximal femur due to minor or major trauma or overuse.
  • Hip fracture: Fracture of proximal femur. Classified as intracapsular or extracapsular.
    • Intracapsular fracture: Femoral head or neck; often associated with disruption of femoral neck vessels; significant morbidity due to AVN:
      • Femoral head fracture: Usually associated with hip dislocation (anterior > posterior).
      • Femoral neck fracture: Usually older adults with minor trauma, or young patient with major trauma; symptoms vary. Patient may or may not be ambulatory. Often site of stress fracture in runners/military recruits.
    • Extracapsular fractures: Below acetabular capsule. Normally do not disrupt blood flow. Morbidity typically due to patient immobilization: DVT, PE:
      • Trochanteric fractures: Greater trochanter usuallyfractured by avulsed at insertion in gluteus medius. Lesser trochanter usually fractured by avulsed from forceful contraction of iliopsoas; seen in young athletes and children.
      • Intertrochanteric fracture: Defined as occurring in line between greater and lesser trochanters. Common in elderly, osteoporosis patients often due to fall. Marked external rotation and shortening. Can be stable or unstable. Nonambulatory.
      • Subtrochanteric fracture: Usually due to direct, significant trauma in younger patients or lesser trauma in elderly. Common site of pathologic fracture. Can be site of significant blood loss and shock.
  • Hip dislocation: Disarticulation of femoral head. Classified as posterior, anterior, and central:
    • Posterior dislocation (most common):
      • Often from motor vehicle accident (MVA) in which knees strike dashboard
      • 10% associated with sciatic nerve injury
    • Anterior dislocation: 10% hip dislocations:
      • Often due to trauma with sudden abduction of thigh
      • Associated femoral head fractures, femoral nerve injury
      • Can be anterior superior, or anterior inferior
    • Central dislocation with acetabular fracture:
      • Usually from direct impact to greater trochanter
      • Associated significant blood loss, sciatic nerve injury

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