Rosen & Barkin's 5-Minute Emergency Medicine Consult (365 page)

Repeat serum sodium levels within a week.

• Up to 30% of acute hypernatremia patients will have permanent neurologic sequelae, a complete and well-documented neurologic exam is a must.
  
• Patients at extreme ages and with chronic conditions are most susceptible to neurologic complications:
  
  • On going fluid losses may require recalculation of fluid needs
    
  • Repeat lab work to confirm controlled correction of sodium
    

• Ellison D. Disorders of sodium and water.
  Am J Kidney Dis
  . 2005;46(2):356–361.
  
• Fall P. Hyponatremia and hypernatremia. A systematic approach to causes and their correction.
  Postgrad Med
  . 2000;107(5):75–82.
  
• Lin M, Lu S, Lim I. Disorders of water imbalance.
  Emerg Med Clin North Am
  . 2005;23:749–770, ix.
  
• Pfennig CL, Slovis CM. Sodium disorders in the emergency department: A review of hyponatremia and hypernatremia.
  Emerg Med Pract
  . 2012;14(10):1–20.
  
• Ranadive SA, Rosenthal SM. Pediatric disorders of water balance.
  Endocrinol Metabol Clin North Am
  . 2009;38(4):663–672.
  

See Also (Topic, Algorithm, Electronic Media Element)

• Diabetic Ketoacidosis
  
• Hyperosmolar Coma
  
• Hyponatremia
  

CODES

• 276.0 Hyperosmolality and/or hypernatremia
  
• 775.5 Other transitory neonatal electrolyte disturbances
  

BASICS

• Results from a relative insulin deficiency in the undiagnosed or untreated diabetic
  
• Sustained hyperglycemia creates an osmotic diuresis and dehydration:
  
  • Extracellular space maintained by the osmotic gradient at the expense of the intracellular space
    
  • Eventually profound intracellular dehydration occurs.
    
• Total body deficits of H
  ₂
  O, Na
  ⁺
  , Cl
  ⁻
  , K
  ⁻
  , PO
  ₄
  ⁻
  , Ca
  ²⁺
  , and Mg
  ²⁺
  
• In contrast to diabetic ketoacidosis (DKA), severe ketoacidosis does not occur:
  
  • Circulating insulin levels are higher.
    
  • The elevation of insulin counter-regulatory hormones is less marked.
    
  • The hyperosmolar state itself inhibits lipolysis (the release of free fatty acids) and subsequent generation of keto acids
    

• Most commonly seen in elderly type II diabetics who experience a stressful illness that precipitates worsening hyperglycemia and reduced renal function
  
• In the elderly, 30–40% of cases are associated with the initial presentation of diabetes.
  

Hyperosmolar hyperglycemic states (HHS) rare in pediatric patients

• Hyperosmolar state precipitated by factors that:
  
  • Impair peripheral insulin action
    
  • Increase endogenous or exogenous glucose
    
  • Decrease patient’s ability to replace fluid loss
    
• Infection is the most common precipitating factor in 32–60% of cases.
  
• Other precipitating causes include:
  
  • Inadequate diabetes therapy
    
  • Medication omission
    
  • Diet indiscretion
    
  • Infections
    
  • Pneumonia
    
  • UTI
    
  • Sepsis
    
  • Medications/drugs
    
  • Diuretics
    
  • β-blockers
    
  • Calcium channel blockers
    
  • Phenytoin
    
  • Cimetidine
    
  • Amphetamines
    
  • Ethanol
    
  • Myocardial infarction
    
  • Stroke
    
  • Renal failure
    
  • Heat stroke
    
  • Pancreatitis
    
  • Intestinal obstruction
    
  • Endocrine disorders
    
  • Burns
    
  • Heat stroke
    

DIAGNOSIS

• Progression of signs and symptoms typically occur over days to weeks.
  
• Polyuria/polydipsia/weight loss
  
• Dizziness/weakness/fatigue
  
• Blurred vision
  
• Leg cramps
  

• Dehydration
  
• Tachycardia
  
• Sunken eyes
  
• Hypotension
  
• Orthostasis
  
• Dry mucous membranes
  
• Decreased skin turgor
  
• Collapsed neck veins
  
• Coma/lethargy/drowsiness
  
• Urinary output maintained until late
  
• Seizures/focal neurologic deficits
  
• Concurrent precipitating medical illness
  

Diagnostic criteria:

• Serum glucose ≥600 mg/dL (usually >1,000 mg/dL)
  
• Minimal ketosis
  
• pH ≥ 7.30, HCO
  ₃
  ≥15 mEq/L
  
• Effective serum osmolality >320 mOsm/kg:
  
  • = 2 × Na
    ⁺
    + glucose/18
    
  • BUN not included because it is freely permeable between fluid compartments
    

• Broad testing indicated to evaluate hyperosmolar syndrome and for precipitating causes
  
• Electrolytes:
  
  • K
    ⁺
    may be elevated even in the presence of total body deficit owing to shift from intracellular space to extracellular space.
    
  • Mild anion gap metabolic acidosis owing to lactic acid, β-hydroxybutyric acid, or renal insufficiency
    
  • Increased sodium—correct for hyperglycemia: Corrected [Na
    ⁺
    ] = [Na
    ⁺
    ] + 1.6 × [(glucose in mg/dL) – 100]/100
    
• BUN, creatinine:
  
  • Azotemia with elevated BUN/creatinine ratio owing to prerenal and intrarenal causes
    
• Venous blood gas (VBG) or arterial blood gas (ABG) to rapidly determine pH:
  
  • ABG necessary to evaluate mixed acid–base disorders
    
• Serum ketones, β-hydroxybutyrate, and lactate level if pH < 7.3 or significantly elevated anion gap to evaluate mixed acid–base disorder
  
• Serum osmolarity
  
• CBC:
  
  • Leukocytosis due to infection, stress, or hemoconcentration
    
  • Increased hemoglobin and hematocrit due to hemoconcentration
    
• Lipase and amylase:
  
  • Pancreatitis common
    
  • Elevated amylase and lipase with no evidence of pancreatitis common
    
  • May be due to increased salivary secretion, hemoconcentration, or decreased renal clearance
    
• Urinalysis:
  
  • Check for ketones/glucose.
    
  • Assess for UTI.
    
• Magnesium, calcium, phosphate
  
• Blood cultures in sepsis
  
• Creatine kinase for rhabdomyolysis:
  
  • Incidence as high as 17%
    
• Urine pregnancy test in females of childbearing years
  
• Cardiac enzymes and troponin for myocardial infarction
  

• CXR to evaluate for possible underlying pneumonia
  
• Head CT: When indicated for AMS or with focal neurologic deficit
  

ECG:

• Evaluate for electrolyte abnormalities causing conduction impairment
  
• Evaluate for signs of ischemia as triggering event
  

Differentiate from DKA:

• If acidosis or significant anion gap present, must determine cause (i.e., ketosis, DKA, lactic acidosis, [hypoperfusion, sepsis, or postictal], or other causes of metabolic acidosis)
  
• Mixed disorder of HHS and DKA present in up to 33% of patients
  

TREATMENT

IV fluid resuscitation and initial stabilization