FLUID BALANCE
Largest fluid compartment in the body?
Intracellular fluid (ICF)- About two-thirds of body water is inside cells.
Most abundant electrolyte in blood plasma?
Sodium (Na⁺)- Sodium is the major extracellular electrolyte.
Hormone that conserves water?
ADH- ADH increases water reabsorption in kidneys.
What electrolyte imbalance causes U waves?
Hypokalemia- Low potassium delays ventricular repolarization.
The patient drank excessive water during a marathon and now has confusion and a headache. What condition is likely?
Water intoxication/hyponatremia- Excess water dilutes sodium concentration.
Main organ responsible for regulating fluid balance?
Kidneys- The kidneys regulate water and electrolyte excretion.
Electrolyte most important for cardiac conduction?
Potassium (K⁺)- Potassium directly affects cardiac electrical activity.
Hormone that retains sodium?
Aldosterone- Aldosterone promotes sodium reabsorption.
What ECG finding is commonly seen in hyperkalemia?
Peaked T waves- High potassium speeds up repolarization.
CHF patient with crackles and edema—fluids or no fluids?
No fluids- The patient already has fluid overload.
Patient has poor skin turgor, tachycardia, and hypotension. What condition does this suggest?
Dehydration- Fluid loss decreases circulating volume, causing compensatory tachycardia and hypotension.
Electrolyte imbalance causing peaked T waves?
Hyperkalemia- High potassium alters ventricular repolarization.
Hormone released when blood volume is too high?
ANH- ANH promotes sodium and water excretion.
What electrolyte imbalance prolongs the QT interval?
Hypocalcemia- Low calcium prolongs ventricular repolarization.
A patient with vomiting, diarrhea, tachycardia, and dry mucous membranes likely has what condition?
Dehydration- GI losses cause fluid volume deficit.
What type of fluid imbalance causes edema and crackles?
Overhydration/fluid volume excess- Excess fluid accumulates in tissues and lungs.
Sign associated with hypocalcemia?
Chvostek sign- Low calcium increases neuromuscular excitability.
What hormone is inhibited by alcohol?
ADH- Alcohol suppresses ADH, causing increased urination.
Which electrolyte imbalance can cause cardiac arrest most rapidly?
Hyperkalemia- Severe hyperkalemia disrupts cardiac conduction.
A septic patient with BP 78/42 should receive what immediate intervention?
IV fluids- Fluids help restore circulating volume and blood pressure.
Which fluid compartment varies MOST in volume?
Interstitial fluid- Interstitial fluid changes rapidly with edema and dehydration.
Patient with confusion, seizures, and sodium 118 likely has what imbalance?
Hyponatremia- Low sodium causes cerebral edema and neurologic symptoms.
A severely dehydrated patient after 3 days of vomiting would release more of what hormone?
ADH- The body attempts to conserve water during dehydration.
Patient on Lasix develops PVCs and U waves. What electrolyte imbalance is likely?
Hypokalemia- Loop diuretics increase potassium loss.
A patient with renal failure has potassium 7.0 and peaked T waves. What is the priority concern?
Cardiac arrest- Severe hyperkalemia can rapidly become fatal.