Flid and Electrolyte/Acid-Base Imbalances

Fluid Volume Deficit

* ECF water loss
* Intake < Output

Fluid Volume Deficit Causes

* Severely decreased oral intake of water and salt.
* Increased GI output: vomit, laxative overuse, etc.
* Loss of blood or plasma.

Fluid Volume Deficit Signs and Symptoms

* Sudden weight loss
* Thirst
* Restlessness
* Confusion
* Hypotension
* Oliguria
* Hypovolemic shock

Fluid Volume Deficit Lab Values

* Hematocrit Increases
* BUN Increases
* Specific Gravity Increases

Fluid Volume Excess

* ECF water gain
* Intake > Output

Fluid Volume Excess Causes

* Excessive administration of IV fluids or water and salt.
* Renal retention of Na+ and water:
* Heart failure
* Cirrhosis
* Renal disease
* Aldosterone or glucocorticoid excess

Fluid Volume Excess Signs and Symptoms

* Sudden weight gain (overnight)
* Confusion
* Edema
* Crackles in the lungs
* Pulmonary edema

Fluid Volume Excess Lab Values

* Hematocrit decreases
* BUN decreases
* Specific Gravity decreases

Hyponatremia

Diluted body fluid

Hyponatremia Causes

* Excessive ADH
* Polydipsia or forced excessive water intake
* Tap-water enemas
* Excessive IV administration of D5W
* Replacement of a large body fluid output with water but no Na+

Hyponatremia and Hypernatremia Signs and Symptoms

* Decreased LOC
* Confusion
* Coma
* Thirst
* Seizures
* Lethargy

Hyponatremia Lab Values

* Na+ < 136 mEa
* Serum osmolality

Hypernatremia

Concentrated body fluids

Hypernatremia Causes

* Diabetes insipidus
* Osmotic diuresis
* Lack of access to water
* Large insensible perspiration

Hypernatremia Lab Values

* Na+ >145 mEq/L
* Serum osmolality: >295 mOsm/kg

Clinical Dehydration

Fluid volume deficit + Hypernatremia

Clinical Dehydration Causes

* All causes of ECV deficit along with poor or no water intake often with a fever causing increased insensible water output.

Clinical Dehydration Signs and Symptoms

* Combination of ECV deficit and hypernatremia findings

K Normal Value

3\.5-5.0 mEq/L

K Function

* Maintains resting membrane potential skeletal, smooth, and cardiac muscle allowing for normal muscle function

K Food Sources

* Fruits
* Potatoes
* Instant coffee
* Molasses
* Brazil nuts

Hyperkalemia Causes

* Increased K intake and absorption
* Oliguria

Hyperkalemia Signs and Symptoms

* Muscle weakness
* Cardiac dysrhythmias
* Cardiac arrest

Hypokalemia Causes

* Diarrhea
* Vomiting
* K wasting diuretics

Hypokalemia Signs and Symptoms

* Muscle weakness
* Cardiac dysrhythmias
* Paralysis

Ca Normal Value

9\.0-10.5 mg/dL

Ca Function

* Influences excitability of nerve and muscle cells
* Necessary for muscle contraction

Ca Food Sources

* Dairy products
* Canned fish with bones
* Broccoli
* Oranges
* Requires vitamin D for best absorption

Hypercalcemia Causes

* Increased Ca intake/absorption
* Some cancers draw Ca out of the bones
* Bone injuries

Hypercalcemia Signs and Symptoms

* Decreased neuromuscular excitability
* Increased lethargy

Hypocalcemia Causes

* Low Ca concentration in the blood
* Commonly seen in pancreatitis patients

Hypocalcemia Signs and Symptoms

* Hyperactive reflexes
* Numbness/tingling of fingers
* Tetany
* Chvostek’s sign

Mg Normal Value

1\.3-2.1 mEq/L

Mg Function

* Influences function of neuromuscular junctions
* Cofactor for numerous enzymes

Mg Food Sources

* Dark leafy greens
* Whole grains
* Some laxatives and antacids
* Undigested fat proteins prevents absorption

Hypermagnesemia Causes

* End-stage renal disease

Hypermagnesemia and Hypomagnesemia Signs and Symptoms

* Lethargy
* Decreased neuromuscular excitability
* Decreased tendon reflexes

Hypomagnesemia Causes

* A shift to Mg’s inactive bound form

Phosphate Normal Value

3\.0-4.5 mEq/L

Phosphate Function

* Produces ATP

Phosphate Food Sources

* Milk
* Processed foods
* Beans
* Dark leafy greens

Metabolic Acidosis Causes

* Ketoacidosis:
* Diabetes
* Starvation
* Alcoholism
* Hypermetabolic state (burns)
* Oliguric renal disease
* Ingestion of acid or acid precursors
* Diarrhea
* Pancreatic fistula
* Renal tubular acidosis

Metabolic Alkalosis Causes

* Excessive sodium bicarbonate administration
* Massive blood transfusion
* Mild or moderate ECV deficit
* Excessive vomiting or gastric suctioning
* Hypokalemia
* Excessive aldosterone

True

True or False: The entire GI tract is lined with K and the bowels are lined with bicarb.

Respiratory Acidosis Causes

* Type B COPD
* Airway obstruction
* Bacterial pneumonia
* Excessive atelectasis
* Severe acute asthma episode
* Respiratory muscle weakness/fatigue
* Chest wall injury or painful surgery
* Drug overdose
* Some types of head injuries

Respiratory Alkalosis Causes

* Hypoxemia
* Acute pain
* Anxiety, psychological distress, sobbing
* Inappropriate mechanical ventilator settings
* Simulation of respiratory control in the brainstem (Ex. Sepsis, meningitis, head injury, aspirin overdose)

Respiratory Acidosis Lab Values

* pH: Below 7.35
* PaCO2: Above 45 mmHg
* HCO3: 21-28 mEq/L
* Retention of CO2

Respiratory Acidosis Signs and Symptoms

* Headaches
* Light-headedness
* Decreased LOC
* Dysrthymias

Respiratory Alkalosis Lab Values

* pH: Above 7.45
* PaCO2: Below 35 mmHg
* HCO3: 21-28 mEq/L
* Blowing off CO2

Respiratory Alkalosis Signs and Symptoms

* Lightheadedness
* Numbness
* Increased rate and depth of respirations
* Excitement/confusion followed by a decreased level of consciousness
* Dysrhythmias

Metabolic Acidosis Lab Values

* pH: Below 7.35
* PaCO2: 80-100 mmHg
* HCO3: Below 21 mEq/L

Metabolic Acidosis Signs and Symptoms

* Decreased LOC
* Abdominal pain
* Dysrhythmias
* Increased rate and depth of respirations

Metabolic Alkalosis Lab Values

* pH: Above 7.45
* PaCO2: 80-100 mmHg
* HCO3: Below 21 mEq/L

Metabolic Alkalosis Signs and Symptoms

* Light-headedness
* Numbness
* Muscle cramps
* Possible excitement and confusion followed by decreased LOC
* Dysthymias

pH Normal Value

7\.35-7.45

PaCO2 Normal Value

35-45 mmHg

HCO3 Normal Value

21-28 mEq/L