Rosen & Barkin's 5-Minute Emergency Medicine Consult (368 page)

See Also (Topic, Algorithm, Electronic Media Element)

Hypoparathyroidism

CODES

• 252.00 Hyperparathyroidism, unspecified
  
• 252.01 Primary hyperparathyroidism
  
• 252.02 Secondary hyperparathyroidism, non-renal
  

BASICS

• Hypertensive crisis
  :
  
  • Severely elevated BP defined by a SBP >179 mm Hg or a DBP >109 mm Hg
    
• Hypertensive urgency
  :
  
  • Severely elevated BP without end-organ damage
    
• Hypertensive emergency
  :
  
  • Severely elevated BP associated with acute end-organ damage
    
• Loss of autoregulation of blood flow in hypertensive emergency:
  
  • Arterioles vasoconstrict to counter pressure
    
  • High pressures overwhelm arterioles and endothelial damage occurs
    
  • Endothelial injury leads to increase permeability, activation of the coagulation cascade and platelets, and deposition of fibrin
    
• Activation of the renin–angiotensin system and the sympathetic nervous system:
  
  • Leads to further vasoconstriction and production of proinflammatory cytokines
    
• End-organ ischemia:
  
  • Renewed release of vasoconstrictors
    
  • Worsened by pressure natriuresis
    
  • Triggers a vicious cycle
    
• Organs affected:
  
  • Brain (encephalopathy, CVA, ICH)
    
  • Retina (hemorrhage, papilledema)
    
  • Heart (MI, aortic dissection, acute HF)
    
  • Kidneys (acute renal failure)
    
  • Placenta (preeclampsia/eclampsia)
    

• Essential HTN
  
• Renal:
  
  • Vascular disease
    
  • Parenchymal disease
    
• Coarctation of the aorta
  
• CNS disorders:
  
  • Head trauma
    
  • CVA/ICH
    
  • Brain tumor
    
  • Spinal cord injury
    
• Endocrine:
  
  • Pheochromocytoma
    
  • Cushing syndrome
    
  • Primary hyperaldosteronism
    
  • Renin-secreting tumor
    
• Drugs:
  
  • Cocaine, phencyclidine, amphetamines
    
  • Erythropoietin, tacrolimus, cyclosporine, corticosteroids, oral contraceptives
    
  • MAOI interactions
    
  • Antihypertensive medication withdrawal
    
  • Lead intoxication
    
• Autonomic hyperreactivity:
  
  • Guillain–Barré syndrome
    
  • Acute intermittent porphyria
    
• Postop pain and/or anesthesia complications
  
• Pregnancy related:
  
  • Preeclampsia/eclampsia
    

DIAGNOSIS

• Inquire about:
  
  • Use of any prescribed and OTC medication
    
  • Duration and control of pre-existing HTN
    
    • Prior end-organ damage
      
  • Details of antihypertensive therapy
    
  • Comorbid conditions (obesity, CAD, DM)
    
  • Recreational drug use
    
• Assess for end-organ compromise in decreasing order of frequency:
  
  • Dyspnea
    
  • Chest pain
    
  • Headache
    
  • Altered mental status/confusion
    
  • Focal neurologic symptoms
    

• BP measured in both arms
  
  • Use proper cuff size
    
• Assess for end-organ compromise:
  
  • Neurologic:
    
    • Level of consciousness
      
    • Visual fields
      
    • Focal motor/sensory deficits
      
  • Ophthalmologic:
    
    • Funduscopic exam (retinal hemorrhages, papilledema)
      
  • Cardiovascular:
    
    • Elevated JVP
      
    • Lung crackles
      
    • Aortic insufficiency murmur
      
    • S3
      
    • Asymmetrical pulses
      

• 12-lead EKG:
  
  • Ischemic changes, LV hypertrophy
    
• Assess kidney function
  
  • Acute renal failure may be asymptomatic
    

• CBC
  
  • Anemia and thrombocytopenia are present in thrombotic microangiopathy
    
• Standard hospital protocols for chest pain
  
• BUN, creatinine
  
• Electrolytes
  
  • Hypokalemia present in primary mineralocorticoid excess
    
• Urinalysis:
  
  • Proteinuria, hematuria, and casts
    
• Urine toxicology screen:
  
  • If recreational drugs are suspected
    
• HCG
  

• Chest x-ray:
  
  • If cardiopulmonary symptoms are present
    
• Head CT:
  
  • If headache, confusion, neurologic findings
    
• CTA chest and abdomen:
  
  • If concern for aortic dissection
    

• Arterial line
  
• Lumbar puncture:
  
  • Exclude subarachnoid hemorrhage
    

• Acute coronary syndrome (ACS)
  
• Acute heart failure (AHF)
  
• Aortic dissection
  
• Intracerebral hemorrhage (ICH)
  
• CVA (ischemic or hemorrhagic)
  
• Preeclampsia/eclampsia
  
• Withdrawal syndromes:
  
  • β-blockers
    
  • Clonidine (central α2-agonist)
    
• States of catecholamine excess:
  
  • Pheochromocytoma
    
  • Cocaine/sympathomimetic drug intoxication
    
  • Tyramine ingestion when on MAOIs
    

TREATMENT

• ABCs
  
• Consider gentle BP reduction.
  

• ABC, cardiac monitoring, pulse oximetry
  
• Oxygen administration
  
• IV access
  

• Hypertensive urgency:
  
  • No need to treat, but close follow-up
    
  • Use oral agents only
    
  • Give any missed home dose
    
  • Goal: Lower the BP gradually over 24–48 hr
    
• Hypertensive emergency:
  
  • Treat end-organ damage, not absolute BP
    
  • Reduce MAP by ≤20–25% in the 1st hr
    
  • Goal: Systolic ∼160 mm Hg, diastolic ∼100 mm Hg in 2–6 hr
    
  • Once BP stable with IV therapy, transition to oral therapy within 6–12 hr
    
  • More gradual reduction recommended in:
    
    • Acute ongoing injury to CNS
      
  • More rapid reduction recommended in:
    
    • Aortic dissection
      
• Hypertensive encephalopathy
  :
  
  • Goal: MAP lowered by max. 20% or to DBP 100–110 mm Hg within 1st hr then gradual reduction in BP to normal over 48–72 hr
    
  • Drug of choice: Nicardipine, clevidipine, or labetalol
    
• Ischemic stroke
  :
  
  • CPP = MAP – ICP
    
  • Decreased CPP from hypotension (low MAP) or cerebral edema (high ICP) may extend infarct
    
  • Treat only SBP >220 mm Hg or DBP >120 mm Hg
    
  • Lytic candidates should have BP lowered to <185/110 mm Hg
    
  • Goal: MAP lowered by no more than 15–20%, DBP not <100–110 mm Hg in first 24 hr
    
  • Goal post tPA: BP <180/105 mm Hg
    
  • Drug of choice: Nicardipine, clevidipine, or labetalol
    
• Hemorrhagic CVA or SAH
  :
  
  • Treat if SBP >180 mm Hg/DBP >100 mm Hg
    
  • Goal: MAP lowered by 20–25% within the 1st hr or SBP 140–160 mm Hg
    
  • Drug of choice: Nicardipine, clevidipine, or labetalol
    
  • Avoid dilating cerebral vessels with nitroglycerin or nitroprusside
    
• ACS:
  
  • Goal: MAP to 60–100 mm Hg
    
  • Drug of choice: Labetalol or esmolol in combination with nitroglycerin
    
  • Avoid: Hydralazine (reflex tachycardia) and nitroprusside (“coronary steal”)
    
• AHF:
  
  • Goal: MAP to 60–100 mm Hg
    
  • Drug of choice nitroprusside or NTG with ACEI and/or loop diuretic
    
• Acute renal failure/microangiopathic anemia:
  
  • Goal: MAP lowered by 20–25% within 1st hr
    
  • Drug of choice: Nicardipine, clevidipine, or fenoldopam. For scleroderma renal crises ACEI are drugs of choice.
    
• Aortic dissection:
  
  • Reduce shear force (dP/dT) by reducing both BP and HR
    
  • β-blockade must precede any drug that may cause reflex tachycardia
    
  • Goal: SBP 100–120 mm Hg and HR <65 bpm within 1st 20 min
    
  • Drug of choice: Esmolol in combination with dihydropyridine CCB or nitroprusside
    
  • Consult vascular surgery if type A
    
• Sympathomimetics (pheochromocytoma, cocaine, amphetamines
  ):
  
  • Goal: MAP lowered by 20–25% within 1st hr
    
  • Avoid pure β-blockade (α is left unopposed)
    
  • Drug of choice: Phentolamine or calcium channel blocker with benzodiazepine. Use clonidine in cases of clonidine withdrawal