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					Fluids & Electrolytes II
         Acid-Base and
    Potassium Disturbances

Mary C. Ottolini M.D., M.P.H.
             Professor of Pediatrics
       Division Chief; Hospitalist Division
Director of Pediatric Medical Student Education
      Children’s National Medical Center
       Learning Objectives:
• Describe common etiologies, presentations
  and complications of managing hypo and
  hyperkalemia
• Describe common etiologies and a diagnostic
  scheme for acid-base disturbances
A 10-year-old boy is brought to the emergency department
because of abdominal pain. Physical examination reveals
evidence of dehydration; respirations are deep and rapid,
but unlabored. The blood glucose level is 640 mg/dL.
Arterial blood gas studies in this patient are MOST likely to
reveal
       pH            PO2(torr)     PCO2(torr)


A.     7.05          110           20
B.     7.10          90            65
C.     7.40          100           20
D.     7.50          110           5
E.     7.55          100           40
A 10-year-old boy is brought to the emergency department
because of abdominal pain. Physical examination reveals
evidence of dehydration; respirations are deep and rapid,
but unlabored. The blood glucose level is 640 mg/dL.
Arterial blood gas studies in this patient are MOST likely to
reveal
       pH            PO2(torr)     PCO2(torr)


A.     7.05          110           20
B.     7.10          90            65
C.     7.40          100           20
D.     7.50          110           5
E.     7.55          100           40
         Acid-Base Disturbance
• H+ + HCO3-  H2CO3  H2O + CO2
       Kidney                                   Lungs
• Calculation of serum anion gap
  – [Na+- (Cl-+ HCO3-)]
  – Normal AG: 5-11 mEq/L; Increased AG: > 11 mEq/L
• pH= pK + log10 ([HCO3-]/0.03PaCO2)
• Golden Rules:
  –   An Acute    in PaCO2 10mmHg =0.08         in pH units
  –   A pH of 0.15 units= HCO3       of 10 mEq/L
  –   or A pH of 0.01 units= HCO3       of 0.67 mEq/L
  –   The Total HCO3 Deficit = Base Deficit (mEg/L)x 0.3 wt (kg)
     Acid-Base Golden Rules
• Measurement of arterial or venous blood gas
• Respiratory Acidosis: PaCO2=50 pH= 7.32
• Metabolic Acidosis: pH=7.25 HCO3 =16
• 25 kg Pt with PaCO2 = 40 pH = 7.18
     HCO3 deficit is calculated as 22(0.67)= 14.7
     Base x       Wt      x     Distribution = HCO3 Dose
     Deficit                    of HCO3
     14.7 x       25 kg x       0.3           = 110 mEq
      Acid-Base Disturbance
• Indications for NaHCO3 therapy:
  – pH < 7.20
  – HCO3- < 8-10 mEq/L
• How Much HCO3-?= Golden Rule #3 usually
  only need to give 1/4- 1/2 of the replacement
• If add to final fluids, must account for extra
  Na+
A 4 yo boy is admitted with a 2 d h/o non-bilious emesis for 2
days. No h/o fever or diarrhea. PE findings are consistent
with moderate dehydration. He is somnolent, but recognizes
his parents. He is breathing a little fast.
Labs: ABG: pH=7.25
                              144 3.8 44

                              94     14       0.9
   What is the anion gap?

   A. 8
   B. 36
   C. 20
   D. 32
   E. 12
A 4 yo boy is admitted with a 2 d h/o non-bilious emesis for 2
days. No h/o fever or diarrhea. PE findings are consistent
with moderate dehydration. He is somnolent, but recognizes
his parents. He is breathing a little fast.
Labs: ABG: pH=7.25
                              144 3.8 44

                              94     14       0.9
   What is the anion gap?

   A. 8
   B. 36
   C. 20
   D. 32
   E. 12
A 4 yo boy is admitted with a 2 d h/o non-bilious emesis for 2 days.
No h/o fever or diarrhea. PE findings are consistent with moderate
Dehydration. He is somnolent, but recognizes his parents. He is
Breathing a little fast.
                           144    3.8      44
Labs: ABG: pH=7.25
                           94      14      0.9

    What is the most likely diagnosis:

      A. Acetaminophen poisoning
      B. RTA
      C. Acute Respiratory alkalosis with metabolic compensation
      D. DKA
      E. Meningitis with SIADH
A 4 yo boy is admitted with a 2 d h/o non-bilious emesis for 2 days.
No h/o fever or diarrhea. PE findings are consistent with moderate
Dehydration. He is somnolent, but recognizes his parents. He is
Breathing a little fast.
                           144    3.8      44
Labs: ABG: pH=7.25
                           94      14      0.9

    What is the most likely diagnosis:

      A. Acetaminophen poisoning
      B. RTA
      C. Acute Respiratory alkalosis with metabolic compensation
      D. DKA
      E. Meningitis with SIADH
  Metabolic Acidosis- Use of Anion
                Gap
Increased anion gap      Normal anion gap
• MUDPILES                 – GI loss of HCO3-
  – M= Methanol               • Diarrhea
  – U= Uremia              – Renal loss of HCO3-
  – D=DKA                     • Proximal (Type II) RTA
  – P= Paraldehyde         – Renal dysfunction
  – I =Inborn Error of        • Hyperkalemic (Type IV)
    Metabolism                  RTA
  – L =Lactic Acidosis        • Distal (Type I) RTA
  – E= Ethylene glycol
  – S= Salicylates
A 9 mo old boy presents wit ha 2 day h/o V and D with 8-10 loose
Stools/day, and vomiting most of his feedings.
PE: T: 98 F RR: 28 HR: 140 BP: 86/58
He is listless, with dry mm, diminished skin turgor, cap refill:3 sec
  Labs:                        44 CBG: pH:7.18 P 24
              132 4.2                                 CO2
                                    Urine pH: 5.0
              104      12     0.9

     What is the most likely explanation for his acidosis?

   A. Accumulation of lactic acid
   B. Keto acidosis
   C. Type 1 RTA
   D. Type 2 RTA
   E. Loss of bicarbonate in the gastrointestinal tract
A 9 mo old boy presents wit ha 2 day h/o V and D with 8-10 loose
Stools/day, and vomiting most of his feedings.
PE: T: 98 F RR: 28 HR: 140 BP: 86/58
He is listless, with dry mm, diminished skin turgor, cap refill:3 sec
  Labs:                        44 CBG: pH:7.18 P 24
              132 4.2                                 CO2
                                    Urine pH: 5.0
              104      12     0.9

     What is the most likely explanation for his acidosis?

   A. Accumulation of lactic acid
   B. Keto acidosis
   C. Type 1 RTA
   D. Type 2 RTA
   E. Loss of bicarbonate in the gastrointestinal tract
     Acid-Base Disturbance
• Metabolic Acidosis
  – Cardinal features
     • Low HCO3-
     • Low pH
     • Low PaCO2 if respiratory compensation
  – Due to either
     • Inability to excrete H+ load
     • Increased H+ load or HCO3- loss
  – Treatment
     • Correction of acidemia using NaHCO3
     • Criteria for treatment listed previously
 A 10 mo girl presents with poor feeding, constipation, irritability
 And failure to gain weight.
 PE= length 10th%; wt < 3rd% VS: RR: 26; HR: 98; BP:86/54
 Muscle mass and fat are diminished.
    Labs:      134     3.1       4    CBG: pH:7.18 pCO2 28
                                      Urine pH: 7 SG: 1.004
               110     12    0.2
Renal Ultrasound shows nephrocalcinosis
 Which of the following is the most likely diagnosis?
 A. Organic Acidemia
 B. RTA type 1
 C. RTA type 2
 D. Urea cycle defect
 E. RTA type 3
 A 10 mo girl presents with poor feeding, constipation, irritability
 And failure to gain weight.
 PE= length 10th%; wt < 3rd% VS: RR: 26; HR: 98; BP:86/54
 Muscle mass and fat are diminished.
    Labs:      134     3.1       4    CBG: pH:7.18 pCO2 28
                                      Urine pH: 7 SG: 1.004
               110     12    0.2
Renal Ultrasound shows nephrocalcinosis
 Which of the following is the most likely diagnosis?
 A. Organic Acidemia
 B. RTA type 1
 C. RTA type 2
 D. Urea cycle defect
 E. RTA type 3
     Renal Tubular Acidosis
• Type I (Distal RTA)
  – Defect in distal tubular acidification (H+ excretion)

• Type II (Proximal RTA)
  – Defect in proximal tubular HCO3- reabsorption

• Type IV (Hyperkalemic RTA)
  – Defect in aldosterone
        Renal Tubular Acidosis
• Normal anion gap, hyperchloremic metabolic acidosis
• Urinary pH:Metered pH, not dipstick
      • pH < 5.5:proximal RTA (Type II) or hyperkalemic RTA (Type
        IV)
      • pH > 5.5: distal RTA (Type I)
• Bicarbonate loading (3-4 mEq/kg/day)
      • FE HCO3- = (Urine HCO3-/Serum HCO3-)/(Urine Cr/Serum Cr)
          – <5%: consistent w/ distal RTA (Type I)
          – 5-10%: consistent w/ hyperkalemic RTA (Type IV)
          – >10-15%: consistent w/ proximal RTA (Type (II)
         Renal Tubule + Aldosterone



         Na+


H+ + HCO3 H+           H2CO3     HCO3
                       CA
          K+                      Cl-
H2CO3
                         H20 +
CA
                         CO2
H20 +
CO2
                                        Basolateral
 Lumen
    Ann Marie Acidosis:
12 week ex 36 week premie female w/ no signifcant
PMHx presents w/ 3 days of profuse diarrhea & poor
oral intake. No fevers or vomiting.
Physical examination:
   – Temp 37.4° C, HR 180, RR 70, BP 85/60, Wt 4.5
      kg
   – Somnolent but irritable; anterior fontanel sunken,
      mucous membranes dry & tacky; decreased skin
      turgor
•Labs:
   – Na+ 138 mEq/L, K+ 4.9 mEq/L, Cl- 118 mEq/L,
      HCO3- 6 mEq/L, BUN/Cr 31/0.6 mg/dL, glucose
      110 mg/dL
   – UA: SG: 1.030 pH 5.0 +Ketones
   – ABG: pH=7.18          PaCO2= 25 PaO2= 100
      HCO3= 8
            Case 3 Continued
  Try to avoid giving HCO3 unless the pt has lost large amounts
                            of HCO3
     and has a persistent metabolic acidosis after initial fluid
                          resuscitation
                     (pH<7.2 and HCO3<10)

If needed add HCO3 to replacement fluids- avoid rapid CNS acid-base
                              shifts



                  In a code- can give 1 mEq/kg

   Can Calculate the Base Deficit or use that already calculated
                 Ann Marie Acidosis:
                  Fluid Calculation
                  Serum Na+= 138
                Na+                Water


                15                  500 cc
Maintenance

                 42                 500 cc   (60% from ECF space)
 Deficit

              500cc(0.6)x 140 mEq/1000cc

  Total          57 mEq              1000cc



Fluid Order: D5 1/3 NS + 20 meQ KCL/L to run at 42 cc/hr
                   Case 3 Continued
 Desired HCO3 (20mEq/L) - Actual HCO3 (6 mEq/L) x Wt x 0.3

           (20mEq/L) - (6 mEq/L) x 5 x 0.3 = 21 mEq

          Generally give 1/4 to 1/2 of the calculated dose= 10 mEq

How much Na HCO3 should be added to fluids to replace half of
HCO3 deficit over 12 hours with a final Na concentration of 57 mEq Na+?
X mEq NaHCO3/1000cc = amount of NaHCO3/volume to be infused

X mEq NaHCO3= 10 mEqNaHCO3/500 cc x 1000cc = 20 mEq

D5 .2 NS = 38 mEq of NaCL + 20 mEq = 58 mEq= 1/3 NS

D5 .2 NS + 20 mEq Na HCO3 to run at 42 cc/hr (twice maintenance)
will replace half of the HCO3 needed over 12 hours and will give Na+
equal to D5.3NS (57 mEq/L)
     Acid-Base Disturbance
• Metabolic Alkalosis
  – Cardinal features
     • High HCO3-
     • High arterial pH
     • High PaCO2
  – Due to either:
     • Loss of H+ or retention of HCO3-
     • Contraction alkalosis
  – Perpetuation of alkalosis caused by:
     • Continued volume or chloride depletion
     • Hyperaldosteronism or hypokalemia
A 4 week old male infant presents with a 2 week history of increasing
non-bilious emesis. He acts hungry and vomits after all oral
intake. His last BM was yesterday. No h/o diarrhea

PE: Alert, moderately dehydrated infant, with an excellent suck
VS: T: 37 RR: 18 HR: 120 BP: 90/46



   Why is this patient’s respiratory rate so slow?

A. He has a urea cycle defect and has a metabolic compensation

B. He has a small bowel obstruction and a metabolic acidosis

C. He has gastric outlet obstruction like pyloric stenosis with a
       metabolic compensation
D. He has gastric outlet obstruction like pyloric stenosis with a
       respiratory compensation

E. He has early gastroenteritis with metabolic acidosis
A 4 week old male infant presents with a 2 week history of increasing
non-bilious emesis. He acts hungry and vomits after all oral
intake. His last BM was yesterday. No h/o diarrhea

PE: Alert, moderately dehydrated infant, with an excellent suck
VS: T: 37 RR: 18 HR: 120 BP: 90/46



   Why is this patient’s respiratory rate so slow?

A. He has a urea cycle defect and has a metabolic compensation

B. He has a small bowel obstruction and a metabolic acidosis

C. He has gastric outlet obstruction like pyloric stenosis with a
       metabolic compensation
D. He has gastric outlet obstruction like pyloric stenosis with a
       respiratory compensation

E. He has early gastroenteritis with metabolic acidosis
                     18
      134   3.1

      89     32     0.5

What would be the most appropriate fluid replacement,
after resuscitation with normal saline boluses?

A. 5% Dextrose with 0.2% saline
 B. 5% Dextrose with 0.2% saline + 20 mEq KCl
 C. 5% Dextrose with 0.45% saline + 20 mEq KCl
 D. 5% Dextrose with 0.45% saline + 10 mEq KPO4

 E. 5% Dextrose with 0.45% saline + 40 mEq KCl
                     18
      134   3.1

      89     32     0.5

What would be the most appropriate fluid replacement,
after resuscitation with normal saline boluses?

A. 5% Dextrose with 0.2% saline
 B. 5% Dextrose with 0.2% saline + 20 mEq KCl
 C. 5% Dextrose with 0.45% saline + 20 mEq KCl
 D. 5% Dextrose with 0.45% saline + 10 mEq KPO4

 E. 5% Dextrose with 0.45% saline + 40 mEq KCl
A 10 year old girl with MRCP, transferred to the floor a week ago from
the PICU following 2 days of mechanical ventilation for
aspiration pneumonia. She was weaned off of Lasix 3 days ago. She has a
persistent O2 requirement and you have been called repeatedly regarding low
RR and HR readings.
PE: Patient is awake, and smiles occasionally- RR increases with
stimulation and albuterol treatments. Lungs are clear. Due to concern for
aspiration the Patient has been NPO.

IV fluids over the past week: D5W 0.3% NS at a maintenance rate

 Which of the following explains her hypoventilation?

 A. Respiratory compensation for a metabolic alkalosis due to Lasix
 B. Metabolic compensation for a Respiratory acidosis
 C. Persistence of a metabolic alkalosis from hypokalemia
 D. Central hypoventilation with metabolic compensation
 E. All of the above
A 10 year old girl with MRCP, transferred to the floor a week ago from
the PICU following 2 days of mechanical ventilation for
aspiration pneumonia. She was weaned off of Lasix 3 days ago. She has a
persistent O2 requirement and you have been called repeatedly regarding low
RR and HR readings.
PE: Patient is awake, and smiles occasionally- RR increases with
stimulation and albuterol treatments. Lungs are clear. Due to concern for
aspiration the Patient has been NPO.

IV fluids over the past week: D5W 0.3% NS at a maintenance rate

 Which of the following explains her hypoventilation?

 A. Respiratory compensation for a metabolic alkalosis due to Lasix
 B. Metabolic compensation for a Respiratory acidosis
 C. Persistence of a metabolic alkalosis from hypokalemia
 D. Central hypoventilation with metabolic compensation
 E. All of the above
A 12 week old white male infant presents with a failure to gain weight since
his 6 week visit. He acts hungry, eats well and has no emesis.
He has 3-4 large, foul smelling stools per day.
PE: Alert, thin, smiling male infant with diaper rash.
VS: T: 37 RR: 24 HR: 120 BP: 90/46



                 134      3.1

                 89        32       0.2
  What test would most likely reveal the diagnosis?

  A. Stool for bacterial culture
  B. Stool for giardia
  C. Sweat test
  D. Immunoglobulins and HIV
A 12 week old white male infant presents with a failure to gain weight since
his 6 week visit. He acts hungry, eats well and has no emesis.
He has 3-4 large, foul smelling stools per day.
PE: Alert, thin, smiling male infant with diaper rash.
VS: T: 37 RR: 24 HR: 120 BP: 90/46



                 134      3.1

                 89        32       0.2
  What test would most likely reveal the diagnosis?

  A. Stool for bacterial culture
  B. Stool for giardia
  C. Sweat test
  D. Immunoglobulins and HIV
   Metabolic Alkalosis- Causes
 •Loss of H+
Gastrointestinal losses
  •Loss of gastric secretions : PYLORIC STENOSIS
  •Antacid therapy
  •Chloride-losing diarrhea
Renal losses
 •Loop or thiazide diuretics
 •Mineralocorticoid excess
 •Postchronic hypercapnia
 •Low chloride intake
 •High dose carbenicillin or other penicillin derivatives
 •Hypercalcemia
H+ translocation into cells
 •Hypokalemia
 •Refeeding syndrome
  Metabolic Alkalosis-Causes
• Retention of HCO3-
  – Massive blood transfusion
  – Administration of NaHCO3
  – Milk-alkali syndrome
• Contraction alkalosis
  – Loop or thiazide diuretics
  – Gastric losses in patients with achlorhydria
  – Sweat loss in cystic fibrosis
     Utility of Urine Chloride in
         Metabolic Alkalosis
Urine Cl- < 25 mEq/L (saline   Urine Cl- > 40 mEq/L (saline
   responsive)                    non-responsive)
    – Vomiting, nasogastric        – Primary mineralocorticoid
      suctioning                     excess
    – Diuretics                    – Diuretics
    – Posthypercapnia              – Alkali load
    – Cystic fibrosis              – Bartter’s or Gitelman’s
    – Low chloride intake            syndromes
                                   – Severe hypokalemia
                                   – Edematous states
       Potassium Disorders
• All conditions causing dehydration
  cause depletion of total body K+ & Na+
  – Serum K+ represents only 2% of total body
    K+
• Never institute K+ repletion until the
  patient has established urine output
• Do not exceed 4 mEq/kg/day of K+
  repletion
               Hyperkalemia
• “Pseudohyperkalemia”
  – Hemolysis
  – Severe leukocytosis> 70,000/cm3 or thrombocytosis
    >1,000,000/cm3
• True hyperkalemia
  – Serum K+> 5.5 mEq/L
  – Mod-severe serum K+> 6.1-6.9 mEq/L
• Adverse effects:
  – Increase PR interval & width of QRS complex, peaked T-
    waves
  – Skeletal muscle weakness & fatigue
  – Smooth muscle respiratory depression
A 4 year old boy with a history of hypertension presents with
a 3 day history of gastroenteritis with fever and profuse, watery
diarrhea. Medications include Motrin and Enalopril. Because of his
watery diarrhea it is unclear when his last urine output was. He
appears significantly dehydrated

Labs:                              64
               135     6.8

               110      10       1.8
 Which of the following explains his hyperkalemia?

A. Decreased GFR from NSAID
B. Decreased GFR from ACE inhibitor
C. Cellular buffering from metabolic acidosis
D. Pre-renal azotemia from dehydration

E. All of the above
A 4 year old boy with a history of hypertension presents with
a 3 day history of gastroenteritis with fever and profuse, watery
diarrhea. Medications include Motrin and Enalopril. Because of his
watery diarrhea it is unclear when his last urine output was. He
appears significantly dehydrated

Labs:                              64
               135     6.8

               110      10       1.8
 Which of the following explains his hyperkalemia?

A. Decreased GFR from NSAID
B. Decreased GFR from ACE inhibitor
C. Cellular buffering from metabolic acidosis
D. Pre-renal azotemia from dehydration

E. All of the above
A 10 day old boy presents with siezures. He was noted to have
Poor feeding over the past 2 days and emesis. His parents are fair
Skinned with blond hair and blue eyes. The baby has blond hair, but
A darkly pigmented scrotum and nipples. He was noted to be
“extremely well-endowed” at the time of circumcision.
(taking after his father)


   Labs:         103                16
                         7.2
                                   8
                 110      14       0.5

 Which of the following is the most likely diagnosis?
 A. Type 1 RTA
 B. Pyloric stenosis
 C. Barter’s syndrome
 D. 21- OH deficiency
 E. 17-OH deficiency
A 10 day old boy presents with siezures. He was noted to have
Poor feeding over the past 2 days and emesis. His parents are fair
Skinned with blond hair and blue eyes. The baby has blond hair, but
A darkly pigmented scrotum and nipples. He was noted to be
“extremely well-endowed” at the time of circumcision.
(taking after his father)


   Labs:         103                16
                         7.2
                                   8
                 110      14       0.5

 Which of the following is the most likely diagnosis?
 A. Type 1 RTA
 B. Pyloric stenosis
 C. Barter’s syndrome
 D. 21- OH deficiency
 E. 17-OH deficiency
         Causes of Hyperkalemia
1) Decrease in K+ excretion
 a) Acute > chronic kidney disease
 b) Addison’s disease or CAH
 c) Drugs:
  i) Potassium sparing agents
  ii) ACE inhibitors
  iii) NSAIDs
  iv) Miscellaneous (TMP-SMX, heparin, pentamidine, alpha- &
  beta-blockers)
       Causes of Hyperkalemia
2)Increase in K+ load: Cellular Destruction
  a) Ingestion of K+ rich diet
 b) Tumor lysis syndrome
 c) Rhabdomyolysis
 d) Trauma
 e) Intravascular hemolysis
 f) Transfusion of stored red blood cells
 g) Catabolic states
      Causes of Hyperkalemia
3) Tubular unresponsiveness to aldosterone
 a) Sickle cell anemia
 b) Systemic lupus erythematosus
 c) Amyloidosis
 d) Renal transplantation
                                 H+
4) Redistribution of    K+
 a) Metabolic acidosis                K+
 b) Infusion of hypertonic solution
 c) Hyperkalemic periodic paralysis
 d)Nonselective Beta-blockers
  A 2 day old infant who has abdominal masses due to large
  Adrenal hemorrhages becomes hypotensive.
  PE: HR: 120 with distant heart sounds, nonpalpable pulses.
  CR Monitor: Wide QRS complexes


The MOST effective immediate intervention for this infant is IV:



A. adenonine
B. Calcium gluconate
C. digoxin
D. dobutamine
E. lidocaine
  A 2 day old infant who has abdominal masses due to large
  Adrenal hemorrhages becomes hypotensive.
  PE: HR: 120 with distant heart sounds, nonpalpable pulses.
  CR Monitor: Wide QRS complexes



The MOST effective immediate intervention for this infant is IV:


A. adenonine
B. Calcium gluconate
C. digoxin
D. dobutamine
E. lidocaine
              Treatment of hyperkalemia
1) Discontinue K+
2) Block cardiac effects
  a) Calcium gluconate 10% 1 ml/kg (100 mg/kg/dose) peripherally
  b) Calcium chloride 27% 0.2 ml/kg (20 mg/kg/dose) through central line
3) Increase cellular uptake of K+
  a) Insulin 1-2 unit regular/5 gm of dextrose
  b) Dextrose 2-4 ml/kg of 25% dextrose
  c) Beta-agonists
   i) Albuterol 5-10 mg nebulized
d) NaHCO3- 1-2 mEq/kg/dose IV (variable response except when accompanied by
    metabolic acidosis)
5) Removal of K+
  a) Sodium polysytrene sulfonate w/ sorbitol (1 gm/kg/dose) PO or PR
  b) Hemodialysis or Peritoneal dialysis
  c) Diuresis
   i) Normal saline bolus 10-20 ml/kg/dose or maintenance fluids a 1-2 x
    maintenance + Lasix 1-4 mg/kg/dose IV
 What is the Most Likely Diagnosis for His Weakness?
A 15 year-old boy comes to the ED because of acute chest pain,
weakness and dizziness, followed by syncope. He has no fever
and denies taking medication or illicit drugs. He has had a 25 lb
weight loss over the last 6 months. He has had a good appetite
and normal bowel movements. Family history is unremarkable.
PE: Slender boy WT: 47.5 kg          HT: 170 cm Otherwise normal
         VS: HR: 65 BP: 109/56 seated and 101/51standing

   Labs:      135      2.5          12 VBG: pH: 7.51/PCO2: 45/HCO3:34
                                98
                        34               EKG: 1st degree block,
              81                  0.8            prolonged QT interval
    Urine pH: 9 Urine Cl-: 5/ Na+: 15/ K+: 4
    CBC, LFTS, Ca and Phos are normal
  A. Diuretic abuse
  B. Addison’s disease
  C. Bulemia Nervosa
  D. Creatine Use
 What is the Most Likely Diagnosis for His Weakness?
A 15 year-old boy comes to the ED because of acute chest pain,
weakness and dizziness, followed by syncope. He has no fever
and denies taking medication or illicit drugs. He has had a 25 lb
weight loss over the last 6 months. He has had a good appetite
and normal bowel movements. Family history is unremarkable.
PE: Slender boy WT: 47.5 kg          HT: 170 cm Otherwise normal
         VS: HR: 65 BP: 109/56 seated and 101/51standing

   Labs:      135      2.5          12 VBG: pH: 7.51/PCO2: 45/HCO3:34
                                98
                        34               EKG: 1st degree block,
              81                  0.8            prolonged QT interval
    Urine pH: 9 Urine Cl-: 5/ Na+: 15/ K+: 4
    CBC, LFTS, Ca and Phos are normal
  A. Diuretic abuse
  B. Addison’s disease
  C. Bulemia Nervosa
  D. Creatine Use
                 Hypokalemia
• Serum K+< 3.5 mEq/L
• Mod-severe serum K+< 2.5-3.0 mEq/L
• Adverse effects:
   – Generalized muscle weakness, cardiac arrhythmias
   – Paralytic ileus, impaired respirations
   – Impaired renal diluting & concentrating abilities
             Causes of Hypokalemia:
          Increase in renal K+ excretion
Metabolic alkalosis
• Chloride responsive
• Choride nonresponsive
   Primary hypoaldosteronism
   Hypertension
       • Liddle’s syndrome
       • 11-B hydroxysteroid dehydrogenase deficiency
   No hypertension
       • Bartter’s syndrome
       • Gitelman’s syndrome
Metabolic acidosis
  RTA
Drugs:
  Diuretics,fludrocortisone,penicillins
              Causes of Hypokalemia:

Transcellular K+ shift
•   Beta-adrenergic agonists
•   Insulin administration
•   Theophylline & caffeine                H+
•   Verapamil & Chloroquine ingestion
•   Hyperthyroidism                   K+
•   Familial hypokalemic paralysis


Excessive K+ loss in stool
• Laxative abuse/diarrheal states
Miscellaneous
•   Mg+2 depletion

				
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posted:3/31/2012
language:Latin
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