Fluid and Electrolytes Flashcards
metabolic acidosis
decreased pH <7.35
decreased HCO3 <22
possible normal PaCO2. Respiratory compensation may occur, causing a decrease in the PaCO2 level.
Urine pH <6
Respiratory acidosis
decreased pH <7.35
increased PaCO2 >45
compensation: kidneys conserve HCO3; eliminate H to increase pH
common causes asphyxia, respiratory and CNS depression
Metabolic alkalosis
increase pH >7.45
increased HCO3 >28
compensation: hypoventilation to increase CO2 kidneys keep H and excrete HCO3
common causes: hypercalcemia, alkaline (antacid) overdose.
respiratory alkalosis
increased pH >7.35
decreased PaCO2 <35
compensation: kidneys eliminate HCO3; conserve H and decrease pH
common causes: hyperventilation, anxiety, diabetic ketoacidosis.
hypercalcemia >10.5
signs & symptoms: weakness, fatigue, anorexia, nausea, vomiting, constipation, polyuria, tingling lips, muscle cramps, confusion, hypoactive bowel tones.
common causes: hyperparathyroidism or malignancies, thiazide diuretics, lithium, renal failure, immobilization, metabolic acidosis.
hypocalcemia < 9
signs & symptoms: anxiety, irritability, twitching around mouth, convulsions, tingling/numbness of fingers, diarrhea, abdominal/muscle cramps, arrhythmias.
common causes: inadequate vitamin D intake, low albumin, renal failure, lactose intolerance, Crohn;s disease, hyperthyroid, increased magnesium, acute pancreatitis.
hyperkalemia >5
signs & symptoms: weakness nausea, diarrhea, hyperactive GI, muscle weakness and paralysis, arrhythmias, dizziness, postural hypotension, oliguria
Common Causes: Potassium-sparing diuretics, NSAIDS, renal failure, multiple transfusions, decreased renal steroids, OD of potassium supplements.
hypokalemia <3.5
signs & symptoms: anorexia, nausea, vomiting, fatigue, decreased LOC, leg cramps, muscle weakness, anxiety, irritability, arrhythmias, postural hypotension, coma
common causes: anorexia, fad diets, prolonged NPO status, alkalosis, transfusion of frozen RBCs, prolonged NGT suctioning
hypermagnesemia >2.1
signs & symptoms: muscle weakness and fatigue are most common, nausea vomiting, flushed skin, diaphoresis, thirst, arrhythmias, palpitations, dizziness.
common causes: increased magnesium intake, chronic renal disease, pregnant women on parenteral magnesium for pre-eclampsia, addison’s disease.
hypomagnesemia <1.3
signs & symptoms: diarrhea, anorexia, arrhythmias, lethargy, muscle weakness, tremors, nausea, dizziness, seizures, irritability, confusion, psychosis, decreased BP, increased HR
Common Causes: prolonged NGT suctioning, diarrhea, laxative abuse, malnutrition, alcoholism, prolonged diuretic use, DKA, digoxin
hypernatremia >145
common signs & symptoms: confusion, fever, tachycardia, low BP, postural hypotension, dehydration, poor skin turgor, dry mucous membranes, flushed.
Common Causes: fever, vomiting, diarrhea, ventilated Pts, severe burns, profuse sweating, diabetes insipidus, diuresis
hyponatremia < 136
signs & symptoms: nausea, vomiting, abdominal cramps, diarrhea, headache, dizziness, confusion, flat affect, decreased DBP, increased HR, postural hypotension, decreased deep tendon reflex.
common causes: diuretic uses, vomiting, diarrhea, burns, hemorrhage, fever, diaphoresis, CHF, renal failure, hyperglycemia, increased ADH
conditions that cause combined acidosis
decreased respiratory rate, kidney dysfunction (oliguria), and dehydration (dry mucous membranes).
After successful resuscitation of cardiopulmonary arrest, the nurse views these arterial blood gases: pH 7.28; CO 2 52; HCO 3 – 16. What is the interpretation of these values?
with a pH of 7.28 (acidosis), there is evidence of a respiratory component (CO 2 > 45) and a metabolic component (HCO 3 – < 21). This is therefore combined respiratory and metabolic acidosis, which would likely follow a cardiopulmonary arrest (CO 2 retention, lactic acidosis). Compensation in respiratory acidosis is demonstrated by an elevated HCO 3 –. In metabolic acidosis, there is very little, if any, change in CO 2. Full compensation would be demonstrated by a normal pH.
Kussmaul respiration
In metabolic acidosis, the rate and depth of breathing increase as the hydrogen ion levels rise. The breathing pattern becomes deep and rapid and not under voluntary control. This type of breathing is known as Kussmaul respiration, which is not present in respiratory alkalosis, respiratory acidosis, or metabolic alkalosis.
Which skin and mucous membrane assessments will the nurse use to evaluate a patient for dehydration?
color, turgor, moisture
insensible water loss
skin, lungs and stool
An older adult patient with a history of renal failure is brought in to the emergency department with sudden onset of acute confusion, worsening muscle weakness in the extremities, abdominal cramps, and a weak, rapid, and thready pulse. What are the immediate nursing interventions to stabilize the patient? Select all that apply.
Administering diuretics
Administering 0.9% saline
Administering 5% dextrose in 0.45% sodium chloride
The patient’s symptoms indicate hypernatremia. Administering diuretics that promote sodium loss and administering fluids such as 0.9% saline and 5% dextrose in 0.45% sodium chloride to restore the fluid balance are the immediate interventions needed to stabilize the patient. The patient’s acute confusion is caused by high sodium levels, so anti-psychotic drugs should not be administered. Sodium decreases the heart contractibility by retarding the movement of calcium into the heart cells. Therefore calcium channel blockers should not be administered.
The nurse is administering sodium chloride 0.9% (normal saline) intravenously to a patient who is dehydrated. Which assessments does the nurse perform to evaluate the effectiveness of rehydration therapy? Select all that apply.
Urinary output
Pulse rate and quality
Pulse rate and quality as well as urinary output best reflect improving volume status with rehydration therapy. Temperature, level of consciousness, and bowel sounds are not indicators of an improving volume state.
A patient is admitted to the intensive care unit with a diagnosis of syndrome of inappropriate antidiuretic hormone secretion (SIADH). Which treatments does the nurse anticipate for this patient? Select all that apply.
Furosemide (Lasix)
Tolvaptan (Samsca)
Conivaptan (Vaprisol
The nurse anticipates the health care provider will prescribe furosemide, tolvaptan, and conivaptan to manage SIADH. Furosemide is a loop-diuretic that helps rid the body of excess fluid. Tolvaptan is used to manage hyponatremia with SIADH. Conivaptan acts as an antidiuretic hormone (ADH) inhibitor to help resolve fluid volume overload. Digitalis is a cardiac glycoside that slows and strengthens myocardial contraction, but it has no effect on fluid volume. Vasopressin is contraindicated with SIADH since it is the synthetic form of ADH. Norepinephrine is a powerful peripheral vasoconstrictor used to increase blood pressure.
Which assessment data is the best indication of perfusion after a surgical procedure?
urine output
The renin-angiotensin II pathway is highly stimulated whenever the patient is in shock or when the stress response occurs. This is why urine output is used as an indicator of perfusion adequacy after surgery or any time the patient has undergone an invasive procedure and is at risk for hemorrhage. Although heart rate, blood pressure, and pulse oximetry are also useful when monitoring perfusion, they are not the most important indicator of perfusion adequacy.
Which situation can cause a patient to experience “insensible water loss?” Select all that apply.
fever diarrhea dry hot weather mechanical ventilation increased respiratory rate
Insensible water loss occurs through the intestinal tract as diarrhea. It can be caused and/or influenced by dry, hot weather. Insensible water loss occurs through the skin, lungs (increased rate of respirations), and intestinal tract. It is increased in patients who are mechanically ventilated, and it is increased by the presence of fever. Nausea with no accompanying vomiting would not cause insensible water loss.
The nurse is caring for a patient with an oxygen saturation of 88% and use of accessory muscles for breathing. The nurse provides oxygen and anticipates which of these health care provider orders?
Intubation and mechanical ventilation
Support with mechanical ventilation may be needed for patients who cannot keep their oxygen saturation at 90% or who have respiratory muscle fatigue. Signs of hypoxemia and work of breathing are present, requiring correction with intubation and mechanical ventilation. Sodium bicarbonate is used to treat metabolic acidosis; this patient displays hypoxemia. Although the underlying reason for this patient’s hypoxemia may eventually require a diagnostic study such as a CT scan of the chest, the priority is to restore oxygenation. There is no clinical evidence of hypokalemia, so administration of potassium chloride is not indicated.
Which patient would be appropriate to assign to the new nurse working on the medical-surgical unit?
- Patient with emphysema and cellulitis with a PaCO 2 level of 58 mm Hg
- Patient with reactive airway disease, wheezing, and a PaO 2 level of 62 mm Hg
- Patient with diabetic ketoacidosis and change in mental status who has a pH of 7.18
- Patient with a small bowel obstruction and vomiting with a bicarbonate level of 40 mEq
Patient with emphysema and cellulitis with a PaCO 2 level of 58 mm Hg
A PaCO2 level of 58 mm Hg in the patient with emphysema and cellulitis, although abnormal, is anticipated for a patient with chronic obstructive pulmonary disease (COPD) and is stable for assignment to a new graduate. The patient with diabetic ketoacidosis and change in mental status is unstable and requires care by a more experienced nurse. The patient with reactive airway disease is still wheezing and requires experienced nursing care. The patient with a small bowel obstruction is unstable and may likely require surgery, which requires more experienced nursing care.
