1
Q
When do you order a BMP?
A
- Hospital Admission
- Fluid Status in Doubt
- Pt on a medication that effects electrolytes (i.e. diuretics)
2
Q
Components of the BMP
A
- Na+
- K+
- Cl-
- HCO3-
- BUN
- Cr
- Ca2+
- Glucose
3
Q
This is the most common electrolyte disorder counting for 5% of hospitalized elderly patients.
A
Hyponatremia
4
Q
Common Cause of Hyponatremia
A
Excess Fluid Build Up
5
Q
Symptoms of Hyponatremia
A
- Headache
- Lethargy
- Confusion
- Seizure
Depends on the rapidity of onset
6
Q
Classification of Hyponatremia
A
- Calculate Serum Osmolality
- Measure Urine Osmolality to eliminate pyschogenic polydipsia
- Assessment of ECF Volume
7
Q
How do you calculate serum osmolality?
A
Osmolality = 2(Na+) + (Glucose/18) + (BUN/2.8)
8
Q
Normal Range of Serum Osmolality of Sodium
A
285-295
9
Q
What is the most common type of Hyponatremia?
A
Low Osmolality Hyponatremia
10
Q
What are the causes of hyponatremia with high extracellular volume?
A
- Heart Failure
- Renal Failure
- Liver Failure/Cirrhosis
11
Q
What are the causes of hyponatremia with normal extracellular volume?
A
- SIADH
- Hypothyroidism
- Adrenal Insufficiency
12
Q
What are the causes of hyponatremia with low extracellular volume?
A
- Vomiting
- Renal Sodium Wasting (Intrinsic vs. Extrinsic/Diuretics)
13
Q
Goals of Therapy for Hyponatremic Patient
A
- Restrict H2O intake or Promote H2O loss
- Replace Sodium if needed (rare)
- Correct the underlying cause
14
Q
How is Hyponatremia Treated?
A
Passively
- For heart, kidney, liver failure, the hyponatremia is usually mild and fluid restriction of approx. 1200 cc of fluid per day is all that is needed.
- Diuretics can be used with caution for faster response or if fluid restriction can’t be adhered to.
15
Q
How is Severe Hyponatremia Treated?
A
Actively
- Coma: Sz related to Hyponatremia
- Can give Saline to Correct
- Need to remember not to correct too quickly
- Rate of correction should be 0.5 mmol per hour (no more than 12 mmol in a day)
16
Q
What is the condition precipitated by correcting hyponatremia too quickly?
A
Central Pontine Myelinolysis
*Manifests by confusion, paralysis, CN deficits (Locked-In Syndrome)
17
Q
Condition where there is excess Anti-Diuretic Hormone causing Hyponatremia
A
SIADH
Syndrome of Inappropriate Anti-Diuretic Hormone Release
18
Q
Function of ADH
A
Promotes Water Retention in the Renal Tubules
19
Q
Hyponatremia is defined by what level of Sodium?
A
< 135
20
Q
Hypernatremia is defined by what level of Sodium?
A
> 145
21
Q
Cause of Hypernatremia
A
- Not enough water in
OR - Too much water out
*Extremely rare to raise sodium by giving too much sodium
22
Q
Causes of “Not Enough Water In” Based Hypernatremia
A
Impaired Thirst
- Can be caused by Tumor or Stroke in Hypothalamus (Osmolality Center)
- No access to water (Common)
23
Q
Causes of “Too Much Water Out” Based Hypernatremia
A
- Dehydration from Heat, Burns, Diarrhea
- Renal Water Loss from Diabetes Insipidus
- Essentially the opposite of SIADH
- Water not absorbed in distal tubule and is wasted in excess sodium
24
Q
Symptoms of Hypernatremia
A
- Thirst
- Hypotension
- Muscle Weakness, Irritability
- Confusion
- Coma, Sz
25
Total Body Water Per Body Weight in Men?
In Women?
60% of Weight Men
50% of Weight Women
26
What is the treatment of Hypernatremia?
Calculate a Water Deficit and Replace over 24 Hours
27
How do you Calculate Water Deficit in Men?
WD = [(Plasma Na+ - 140) x TBW] / 140
28
This is primarily an intracellular cation and can increase when there is lysis of the cells.
Potassium
29
Normal Range for Potassium
3.5-5.2 mEq/L
30
T/F: Potassium Levels 3.5 to 2.0 are usually well tolerated.
False.
K+ Levels 3.5-3.0 are usually well tolerated
31
Manifestations of Hypokalemia (Less than 3.0)
- Fatigue
- Myalgia
- Muscle Weakness
Severe:
- Muscle Failure
- Paralysis
- Hypoventilation
- Ileus
32
Hypokalemia on an EKG?
- Flat T wave
- U wave
- ST Depression
- Wide QRS
33
Causes of Hypokalemia
1. Shift of K+ into cells (Insulin and Metabolic Alkalosis)
2. Non-Renal Loss of K+ (NG Suction and Vomiting)
3. Renal Losses of K+ (MOST COMMON)
4. Diuretics
5. Hyperaldosteronism
34
Treatment of Hypokalemia
Rule of Thumb: Replace 10 meq for each 0.1 that is low.
35
T/F: Oral therapy for Hypokalemia is safest but not fast enough if arrhythmias are serious or if the patient is vomiting.
True
36
T/F: Using IV Potassium is safe and rapid treatment for Hypokalemia
False, it is potentially dangerous (But it is rapid)
37
Etiology of Hyperkalemia (>5.0)
Almost Always Due to Impaired Secretion of K+
1. Renal Failure
2. Drugs
38
What drugs can lead to Hyperkalemia?
1. K+ Sparing Diuretics (Sprinolactone)
| 2. Cardiac Meds (Beta Blockers, ACE Inhibitors, Heparin, NSAIDS)
39
What is the main EKG Finding of Hyperkalemia?
Peaked T wave
40
How is Hyperkalemia treated (General Consideration)?
*Dependent on EKG and Condition of Patient
41
How is Hyperkalemia treated if EKG Changes are present?
Acute Therapy! Works in 60-90 mins
- Calcium Gluconate
- Insulin
- Bicarbonate
- Diuretics - Lasix
- Albuterol
- Dialysis
42
How is Hyperkalemia treated if no EKG Changes are present?
Kayexalate
*Exchanges Na for K in GI tract
Works in 2 hours lasts for 6 hours
43
Top Cause of Hypercalcemia
Hyperparathyroidism!!!!
44
Second Most Common Cause of Hypercalcemia
Cancer
45
Other Causes of Hypercalcemia
- Granulomes
- Thiazides
- Vitamin D
- Renal Failure
46
Manifestations of Hypercalcemia
- Nausea
- Constipation
- Fatigue
- Polyuria
- Renal Stones
47
Acute Treatment of Hypercalcemia
- Saline
- Lasix
- Bisphosphonates, Calcetonin
48
Ultimate Treatment of Hypercalcemia
Removal of Parathyroid or Cancer Causing Agent
49
Major Causes of Hypocalcemia (Broad Categories)
1. Loss of Ca2+ from the Circulation
2. Hypoparathyroidism
3. Disorders of Magnesium Metabolism
4. Vitamin D Deficiency
5. Other
50
Major Causes of Hypocalcemia due to Loss of Ca2+ from the Circulation
- Hypophosphatemia
- Acute Pancreatitis
- Osteoblastic Metastases
- Intravascular Complexing with Citrate, Lactate, Foscarnet, EDTA
- Acute Respiratory Alkalosis
51
Major Causes of Hypocalcemia due to Hypoparathyroidism
- After parathyroid, thyroid, or radical neck surgery
- Idiopathic - may be assc. with chronic mucocutaneous candidiasis and primary adrenal insufficiency (HAM)
- Infiltration of the parathyroid gland
- HIV Infection
- Pseudohyperparathyroidism
52
Major Causes of Hypocalcemia due to "Other"
- Sepsis
- Autosomal Dominant Hypocalcemia
- Fluoride Intoxification
53
T/F: Not many pure chloride disorders as it is mainly and anionic balance for Na+.
True!
Therefore hypo and hyperchloremia are treated like hypo and hypernatremia.
54
Hyperchloremic metabolic acidosis occurs in 80 percent of patients with __________ and is due to two factors:
The colon has an exchange pump which reabsorbs chloride as bicarbonate is secreted. So, when chloride rich urine enters the colon and is absorbed, the secretion and elimination of bicarbonate will result in metabolic acidosis.
Ureterosigmoidostomy
55
This element is primarily used in regards to acid-base disorders.
Bicarbonate (Buffer)
56
What could cause elevations of Bicarbonate?
- Chronic Respiratory Acidosis
| - Metabolic Alkalosis
57
What could cause decreased levels of Bicarbonate?
- Renal Loss
- GI Loss
- Buffering Excess Acid (High Anion Gap)
58
Anion Gap Equation
Na - (Cl + HCO3)
Normal: 4-12
59
What is the Anion Gap?
- The unmeasured Anions in the Blood
| - Proteins and Acids
60
When there is an elevated anion gap acidosis this means there is additional anions in the blood that are unaccounted for. What could cause this?
```
Methanol
Uremia
DKA/AKA
Paraldehyde
Ingetions
Lactic Acidosis
Ethylene Glycol
Salicylates
```
61
This is a rough measure of Glomerular Filtration Rate (GFR), but it is NOT always reliable because this can change independent of the GFR.
BUN (Blood Urea Nitrogen)
62
What could cause an increase in BUN?
- High Protein Diet
- Tissue Breakdown
- Hemorrhage
- Trauma
- Dehydration
63
What could cause a decrease in BUN?
- Low Protein Diet
| - Liver Disease
64
Why does BUN rise with Dehydration?
- 50% of filtered urea is reabsorbed in the proximal tubule.
- When volume depleted - Na+ and H2O reabsorption increases, there is a parallel increase in urea reabsorption.
- As a result, BUN rises.
65
What equation do you use to estimate Creatinine Clearance?
Cockcroft-Gault
[(140-age) x (lean body weight in kg)] / (Plasma Cr x 72)
66
T/F: A drop in Cr is almost always representative of a reduction in GFR.
False.
A RISE in Cr is almost always representative of a reduction in GFR.
67
This is a condition defined by low ADH secretion (Centrally). It has a decreased sensitivity in the Kidneys.
Diabetes Insipidus
68
In Diabetes Insipidus, _____ of ADH causes lack of water re-absorption in distal tubule.
Results is ______ amounts of dilute urine and ____natremia.
LOW;
HIGH;
Hyper
69
Treatment of Central Diabetes Insipidus
DDAVP (Nasal Spray)
70
Treatment of Nephrogenic Diabetes Insipidus
Diuretic (Thiazide)
Lab Medicine
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