Part 2 Module 2 Fluids and Electrolytes Sodium Potassium PDF

Prepared by: Philip Winston Yap, PhRN, USRN Fidel G. Yongque III, PhRN, USRN Geraldine Malayo, CNN, RN HYPONATREMIA W H AT I S … ? Hyponatremia refers to a serum sodium level that is less than 135 mEq/L (135 mmol/L) (Criddle, 2006). E T I O L O G Y & R I S K FA C TO R S E...

Prepared by: Philip Winston Yap, PhRN, USRN Fidel G. Yongque III, PhRN, USRN Geraldine Malayo, CNN, RN HYPONATREMIA W H AT I S … ? Hyponatremia refers to a serum sodium level that is less than 135 mEq/L (135 mmol/L) (Criddle, 2006). E T I O L O G Y & R I S K FA C TO R S E T I O L O G Y & R I S K FA C TO R S Loss of sodium, as in use of diuretics, loss of GI fluids, renal disease, and adrenal insufficiency. Gain of water, as in excessive administration of D5W and water supplements for patients receiving hypotonic tube feedings; disease states associated with SIADH such as head trauma and oat-cell lung tumor; medications associated with water retention (oxytocin and certain tranquilizers); and psychogenic polydipsia. Hyperglycemia and heart failure cause a loss of sodium. C L I N I C A L M A N I F E S TAT I O N S Anorexia, nausea and vomiting, headache, lethargy, dizziness &confusion, muscle cramps and weakness, muscular twitching &seizures, papilledema, dry skin, pulse, BP, weight gain &edema DIAGNOSTIC STUDIES serum sodium Assessment includes the urine sodium history and physical urine specific gravity examination, including a osmolality focused neurologic examination; evaluation of signs and symptoms as well as laboratory test results; identification of current IV fluids, if applicable; and a review of all medications the patient is taking. MEDICAL MANAGEMENT SODIUM REPLACEMENT The most common treatment for hyponatremia is careful administration of sodium by mouth, nasogastric tube, or a parenteral route. The usual daily sodium requirement in adults is approximately 100 mEq, provided there are not excessive losses. MEDICAL MANAGEMENT For those who cannot consume sodium, lactated Ringer’s solution or isotonic saline (0.9% sodium chloride) solution may be prescribed. Serum sodium must not be increased by more than 12 mEq/L in 24 hours to avoid neurologic damage due to osmotic demyelination.  MEDICAL MANAGEMENT In a patient with normal or excess fluid volume, hyponatremia is treated by restricting fluid to a total of 800 mL in 24 hours. This is far safer than sodium administration and is usually an effective treatment. If neurologic symptoms are severe (e.g., seizures, delirium, coma), as well as in traumatic brain injury, it may be necessary to administer small volumes of a hypertonic sodium solution.  MEDICAL MANAGEMENT The prescribed volume of hypertonic saline administered depends on the patient’s weight and on current and desired serum sodium levels (Mortimer & Jancik, 2006). If edema exists alone, sodium is restricted; if edema and hyponatremia occur together, both sodium and water are restricted.  MEDICAL MANAGEMENT Highly hypertonic sodium solutions (2% to 23% sodium chloride) should be administered only in intensive care settings under close observation, because only small volumes are needed to elevate the serum sodium concentration from a dangerously low level. These fluids are administered slowly and in small volumes, and the patient is monitored closely.  MEDICAL MANAGEMENT AVP receptor antagonists are new pharmacologic agents that treat hyponatremia by stimulating free water excretion (Haskal, 2007).  MEDICAL MANAGEMENT IV conivaptan hydrochloride (Vaprisol) use is limited to the treatment of hospitalized patients. It may be a useful therapy for those patients with moderate to severe symptomatic hyponatremia, But, it is contraindicated in patients with seizures, delirium, or coma, which warrant the use of hypertonic saline (Ellison & Berl, 2007; Hayes, 2007a). NURSING MANAGEMENT STRICTLY! Monitor fluid I&O as well as daily body weight. It is also necessary to note abnormal losses of sodium or gains of water, as well as GI manifestations such as anorexia, nausea, vomiting, and abdominal cramping. The nurse must be alert for central nervous system changes, such as lethargy, confusion, muscle twitching, and seizures. NURSING MANAGEMENT For a patient with abnormal losses of sodium who can consume a general diet, the nurse encourages foods and fluid with high sodium content. If the primary problem is water retention, it is safer to restrict fluid intake than to administer sodium. In severe hyponatremia, the aim of therapy is to elevate the serum sodium level only enough to alleviate neurologic signs and symptoms.  NURSING MANAGEMENT When administering fluids to patients with cardio vascular disease, the nurse assesses for signs of circulatory overload (e.g., cough, dyspnea, puffy eyelids, dependent edema, weight gain in 24 hours). The lungs are auscultated for crackles.  NURSING MANAGEMENT For the patient taking lithium, the nurse observes for lithium toxicity, particularly when sodium is lost by an abnormal route. For all patients on lithium therapy, adequate salt intake should be ensured. Excess water supplements are avoided in patients receiving isotonic or hypotonic enteral feedings, particularly if abnormal sodium loss occurs or water is being abnormally retained (as in SIADH). HYPERNATREMIA W H AT I S … ? Hypernatremia is a serum sodium level higher than 145 mEq/L (145 mmol/L). E T I O L O G Y A N D R I S K FA C TO R S Water deprivation in patients unable to drink at will, Hypertonic tube feedings without adequate water supplements, Diabetes insipidus, Heatstroke, Hyperventilation, Watery diarrhea, Burns and diaphoresis. Excess corticosteroid, sodium bicarbonate, and sodium chloride administration, Salt water near-drowning victims C L I N I C A L M A N I F E S TAT I O N S Thirst, elevated body temperature, swollen dry tongue and sticky mucous membranes, hallucinations, lethargy, restlessness, irritability, focal or grand mal seizures, pulmonary edema, hyperreflexia, twitching, nausea, vomiting, anorexia, pulse, and BP DIAGNOSTIC STUDIES MEDICAL MANAGEMENT Infusion of a hypotonic electrolyte solution (eg, 0.3% sodium chloride) or an isotonic non-saline solution (e.g., dextrose 5% in water[D5W]). Clinicians consider a hypotonic sodium solution to be safer than D5W because it allows a gradual reduction in the serum sodium level, thereby decreasing the risk of cerebral edema. D5W is indicated when water needs to be replaced without sodium. It is the solution of choice in severe hyperglycemia with hypernatremia.  MEDICAL MANAGEMENT DIURETICS also may be prescribed to treat the sodium gain. As a general rule, the serum sodium level is reduced at a rate no faster than 0.5 to 1 mEq/L/h to allow sufficient time for readjustment through diffusion across fluid compartments. Desmopressin acetate (DDAVP), a synthetic antidiuretic hormone, may be prescribed to treat diabetes insipidus if it is the cause of hypernatremia (Porth & Matfin, 2009).  NURSING MANAGEMENT STRICTLY! Monitor I&O. Assess for abnormal losses of water or low water intake and for large gains of sodium, as might occur with ingestion of OTC medications that have a high sodium content (e.g., Alka-Seltzer). Obtains a medication history, because some prescription medications have a high sodium content. Notes the patient’s thirst or elevated body temperature and evaluates it in relation to other clinical signs. Monitors for changes in behavior, such as restlessness, disorientation, and lethargy.  NURSING MANAGEMENT If fluid intake remains inadequate, the nurse consults with the physician to plan an alternative route for intake, either by enteral feedings or by the parenteral route. If enteral feedings are used, sufficient water should be administered to keep the serum sodium and BUN within normal limits. As a rule, the higher the osmolality of the enteral feeding, the greater is the need for water supplementation.  NURSING MANAGEMENT For patients with diabetes insipidus, adequate water intake must be ensured. If the patient is alert and has an intact thirst mechanism, merely providing access to water may be sufficient. If the patient has a decreased level of consciousness or other disability interfering with adequate fluid intake, parenteral fluid replacement may be prescribed. HYPOKALEMIA W H AT I S … ? Hypokalemia (below 3.5 mEq/L [3.5 mmol/L]) usually indicates a deficit in total potassium. E T I O L O G Y A N D R I S K FA C TO R S C L I N I C A L M A N I F E S TAT I O N S Severe hypokalemia can cause death through cardiac or respiratory arrest. It can lead to an inability of the kidneys to concentrate urine, causing dilute urine (resulting in polyuria, nocturia) and excessive thirst. Potassium depletion suppresses the release of insulin and results in glucose intolerance. Decreased muscle strength and DTRs can be found on physical assessment. C L I N I C A L M A N I F E S TAT I O N S DIAGNOSTIC STUDIES Assessment includes the history and physical examination, including an electrocardiogram. flattened T waves, prominent U waves, ST depression,prolonged PR interval MEDICAL MANAGEMENT Potassium loss must be corrected daily; administration of 40 to 80 mEq/day of potassium is adequate in the adult if there are no abnormal losses of potassium. Dietary intake of potassium in the average adult is 50 to 100 mEq/day. Foods high in potassium include most fruits and vegetables, legumes, whole grains, milk, and meat. MEDICAL MANAGEMENT MEDICAL MANAGEMENT Many salt substitutes contain 50 to 60 mEq of potassium per teaspoon and may be sufficient to prevent hypokalemia. If oral administration of potassium is not feasible, the IV route is indicated. The IV route is mandatory for patients with severe hypokalemia (e.g., serum level of 2 mEq/L). MEDICAL MANAGEMENT Oral potassium supplements can produce small bowel lesions; therefore, the patient must be assessed for and cautioned about abdominal distention, pain, or GI bleeding. MEDICAL MANAGEMENT Potassium is NEVER administered by IV push or intramuscularly to avoid replacing potassium too quickly. IV potassium must be administered using an infusion pump. NURSING MANAGEMENT Because hypokalemia can be life-threatening, the nurse needs to monitor for its early presence in patients who are at risk. WOF! Fatigue, anorexia, muscle weakness, decreased bowel motility, paresthesias, and dysrhythmias are signals that warrant assessing the serum potassium concentration. NURSING MANAGEMENT Prevention may involve encouraging the patient at risk to eat foods rich in potassium (when the diet allows). STRICTLY! check fluid I&O is necessary, because 40 mEq of potassium is lost for every liter of urine output. The ECG is monitored for changes, and arterial blood gas values are checked for elevated bicarbonate and pH levels. NURSING MANAGEMENT Renal function should be monitored through BUN and creatinine levels and urine output if the patient is receiving potassium replacement. WOF! Signs of Hyperkalemia during potassium replacement. WOF! Signs of oliguria = STOP! potassium administration. Potassium is primarily excreted by the kidneys; when oliguria occurs, potassium administration can cause the serum potassium concentration to rise dangerously (Hayes, 2007b). HYPERKALEMIA W H AT I S … ? Hyperkalemia (greater than 5.0 mEq/L [5 mmol/L]) seldom occurs in patients with normal renal function (Vacca, 2008). Like hypokalemia, hyperkalemia is often caused by iatrogenic (treatment-induced) causes. E T I O L O G Y A N D R I S K FA C TO R S E T I O L O G Y A N D R I S K FA C TO R S C L I N I C A L M A N I F E S TAT I O N S Muscle weakness, tachycardia bradycardia, dysrhythmias, flaccid paralysis, paresthesias, intestinal colic, cramps, abdominal distention, irritability, anxiety. DIAGNOSTIC STUDIES Assessment includes the history and physical examination, including an electrocardiogram. tall tented T waves, prolonged PR interval and QRS duration, absent P waves, ST depression DIAGNOSTIC STUDIES Arterial blood gas analysis (ABG) may reveal both a metabolic and respiratory acidosis. Correcting the acidosis helps correct the hyperkalemia. MEDICAL MANAGEMENT An ECG should be obtained immediately to detect changes. Shortened repolarization and peaked T waves are seen initially. To verify results, a repeat serum potassium level should be obtained from a vein without an IV infusing a potassium-containing solution. MEDICAL MANAGEMENT Prevention of serious hyperkalemia by the administration, either orally or by retention enema, of cation exchange resins (e.g., sodium polystyrene sulfonate [Kayexalate]) may be necessary in patients with renal impairment. MEDICAL MANAGEMENT DO NOT give! if the patient has a paralytic ileus, because intestinal perforation can occur. Kayexalate binds with other cations in the GI tract and contributes to the development of hypomagnesemia and hypocalcemia; It may also cause sodium retention and fluid overload, and should be used with caution in patients with heart failure. MEDICAL MANAGEMENT Calcium antagonizes the action of hyperkalemia on the heart, but it does not reduce the serum potassium concentration. Calcium chloride and calcium gluconate are not interchangeable; calcium gluconate contains 4.5 mEq of calcium and calcium chloride contains 13.6 mEq of calcium. Therefore, caution is required. MEDICAL MANAGEMENT Monitor BP is essential to detect hypotension, which may result from the rapid IV administration of calcium gluconate. Monitor ECG during administration; the appearance of bradycardia is an indication to STOP THE INFUSION. The myocardial protective effects of calcium last about 30 minutes. MEDICAL MANAGEMENT IV sodium bicarbonate = to alkalinize the plasma, cause a temporary shift of potassium into the cells, and furnish sodium to antagonize the cardiac effects of potassium (Vacca, 2008). Effects of this therapy begin within 30 to 60 minutes and may persist for hours; however, they are temporary. MEDICAL MANAGEMENT IV administration of regular insulin and a hypertonic dextrose solution causes a temporary shift of potassium into the cells. Glucose and insulin therapy has an onset of action within 30 minutes and lasts for several hours. MEDICAL MANAGEMENT Loop diuretics, such as furosemide (Lasix), increase excretion of water by inhibiting sodium, potassium, and chloride reabsorption in the ascending loop of Henle and distal renal tubule. MEDICAL MANAGEMENT Beta-2 agonists, such as albuterol (Proventil, Ventolin), are highly effective in decreasing potassium, but their use remains controversial, because they can cause tachycardia and chest discomfort (Porth & Matfin, 2009). Beta-2 agonists move potassium into the cells and may be used in the absence of ischemic cardiac disease. MEDICAL MANAGEMENT If the hyperkalemic condition is not transient, actual removal of potassium from the body is required through cation exchange resins, peritoneal dialysis, hemodialysis, or other forms of renal replacement therapy. NURSING MANAGEMENT Observes for signs of muscle weakness and dysrhythmias (CHECK ECG!). The presence of paresthesias and GI symptoms such as nausea and intestinal colic are noted. Serum potassium levels, as well as BUN, creatinine, glucose, and arterial blood gas values, are monitored for patients at risk for developing hyperkalemia (Heitz & Horne,2005). NURSING MANAGEMENT STRICTLY! Avoid Potassium-rich foods. Care is taken to administer and monitor potassium solutions closely. Particular attention is paid to the solution’s concentration and rate of administration. WOF! Signs of hypokalemia while administering loop diuretics, cation exchange resins, IV calcium gluconate, and other drugs that can lower potassium level. REFERENCES Hinkle, Janice L., Cheever, Kerry H. (2022). Bruner and Suddarth’s Textbook of Medical- Surgical Nursing, 15th Edition, Wulters Kluwer Black, Joyce M., Hawks, Jane, Hokanson (2008). Medical-Surgical Nursing Clinical Management for Patient Outcomes, 8th Edition, Elsevier (Singapore) Pte Ltd. Doenges, Marilynn E. et. al. (2016). Nurse’s Pocket Guide Diagnoses, Prioritized Interventions, and Rationales, 15th Edition, F.A. Davis Company. Taylor, Carol, Lynn, Pamela, Bartlett, Jennifer L. (2019). Fundamentals of Nursing: The Art & Science Patient-Centered Care, 9th Edition, Wolters Kluwer.