Lecture 6.1 - Electrolyte Imbalances Flashcards
Which demographics are most vulnerable to dehydration from vomiting?
Older adults, children, and infants
What is the normal range for sodium in blood?
136-145 mEq/L
What cation is most common in ECF?
Na makes up 90% of ECF, being the main factor in determining ECF volume
changes in K effect the heart. What do changes in Na do?
Effect the brain
What can cause hypernatremia? What can it lead to and how does the body protect from it?
–> Excessive intake
–> Diabetes insopidus
–> Renal failure
–> Cushing Syndrome
Causes hyperosmolarity leading to cellular dehydration
Protected with thirst centre in hypothalamus
What are the manifestations for moderate and severe hypernatremia?
Moderate: Confusion, thirst, dry mucous membranes, low urinary output
Severe: HTN, tachycardia, flushed skin
–> Restlessness, agitation, confusion, seizures, coma
–> Hyper-reflexia, muscle twitching
Nausea, vomiting
–> Poor tissue turgor
How do we correct hypernatremia?
Fluids, diuretics to increase sodium output
–> Monitor daily weights, neuro deterioration, fluid imbalance
What are some nursing diagnoses associated with hypernatremia?
Electrolyte imbalance
Risk for injury: seizures
What is the normal potassium level?
3.5-5.1 mmol/L
What is the major ICF cation?
Potassium
Sodium is necessary for:
Maintaining fluid levels and regulating blood fluids to prevent low blood pressure.
Helps muscles contract, and sends nerve impulses throughout the body
Potassium is necessary for:
–> Transmission and conduction of nerve and muscle impulses
–> Cellular growth
–> Maintain cardiac rhythms (depolarizes and generates APs, low K is shown as a flat T wave in cardiac rhythm)
–> Regulates protein synthesis, and glucose storage and use.
K administration should never exceed what? Why?
20 mEq/hr
–> Prevents hyperK + cardiac arrest
–> Burns when infusing
What is the normal range for calcium? What is is necessary for?
2.10-2.75 mmol/L
–> Blood clotting
–> Muscle contraction (including myocardium)
–> Nerve function
What is the normal serum range for magnesium?
0.65-1.05 mml/L
What is the normal serum level for phosphorus? What does it do?
1.0-1.5 mmol/L
–> Activates vitamins and enzymes, forms ATP, and assists in cell growth and metabolism
–> Maintains acid-base balance
–> Maintains calcium homeostasis.
What are the different kinds of fluid spacing?
First Spacing
–> Normal distribution of ICF and ECF
Second Spacing
–> Abnormal accumulation on interstitial fluid (edema)
Third Spacing
–> Fluid accumulation in a part of the body not easily exchanged with ECF and in transcellular space
–> Fluid fills cavity and compresses soft structures, resulting in ascites, pleural effusions, pericardiac effusion or tamponade
We have to have a normal ____ before administering IV P-dye
Creatinine - verifies kidney function
What is pOSM?
Serum osmolarity by weight
What is an eGFR?
Creatinine clearance/24 hours to measure kidney function
What does ACTH do?
Triggers the release of aldosterone –> Sodium reapsorption
What does ADH do?
Signals for water reabsorption in the renal tubules/collecting ducts.
What does renin do?
Signals for Ang I (+ ACE) –> Vasoconstriction and aldosterone
What are some potential causes for hyponatremia?
Excessive loss through sweat, GI loss, or renal dysfunction.
Excessive H2O gain
What are the manifestations of hyponatremia?
HypoTN
Seizures, decreased muscle tone, twitching, tremors, weakness
V&D, cramping, anorexia
How can hyponatremia be treated?
Hypertonic IVF and fluid restriction
–> Consume salty food
Monitor for neuro and BP changes
What might cause hyperkalemia?
Massive cell destruction - such an in traumatic injury, severe infection, burns or anything that shifts ICF to ECF
Drugs: K-Sparing (Spironolactone, amiloride), ACE Inhibitors
Impaired renal excretion - renal failure most common
What are the manifestations of hyperkalemia?
Oliguria, renal failure
Addison’s disease, brady, arrhythmias
Cramping leg pain, abd cramps or dirrhea.
How is hyperkalemia treated?
Monitor: ECG
Hold K intake, use loop diuretics to excrete it.
Force K back into ECF with insulin or sodium bicarb
Calcium gluconate can reverse membrane effects of elevated ECF K.
Dialysis.