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Chapter 41 Fluid, Electrolyte, and Acid-Base Balance Characteristics of Body Fluids Fluid = Water that contains dissolved or suspended substances such as glucose, mineral salts, and proteins. Fluid amount = Volume. Fluid concentration = Osmolality. Fluid composition (electrolyte concentration) Degree of acidity = pH Scientific Knowledge Base : Location and Movement of Water and Electrolytes Intracellular Fluid (ICF) Extracellular Fluid (ECF) = Fluid outside of cells = Fluids within cells ~2/3 of total body water ~1/3 of total body water Three divisions: – Interstitial – Intravascular – Transcellular Hemoglobin • The hemoglobin test measures the amount of hemoglobin in blood and is a good measure of the blood’s ability to carry oxygen throughout the body. Norm Males: 13.2-17.3 g/dL Females: 11.7-15.5 g/dL Hematocrit This test measures the amount of space (volume) red bloods cells take up in the blood. The value is given as a % of RBCs in a volume of blood. For example, a hematocrit of 38 means that 38% of the blood’s volume is made of RBCs. Norm: Male: 39%-50% Females: 35%-47% Hematocrit ECF Volume deficit Hypovolemia Causes Abnormal fluid loss Diarrhea Fistula drainage Hemorrhage Polyuria Fever (↑ perspiration) Inadequate intake Osmotic diuresis 7 ECF Volume deficit Hypovolemia: Sign and Symptoms Cardiovascular Changes Mild to moderate Respiratory Changes ↑ respiratory rate ↑ HR (due to SNS) Peripheral pulses are weak, difficult to find Change in position may cause ↑ HR or ↓ BP Dizziness and lightheadedness Severe fluid volume ↓ BP in lying position Pulse: weak, thready Flattened neck veins 8 ECF Volume deficit Hypovolemia: Sign and Symptoms Renal Changes UO below 500 mL/day Neurologic changes Alteration in Mental Status Restlessness Drowsiness Lethargy Confusion (more common in the elderly; may be first indicator of fluid balance problem) Seizures, coma 9 ECF Volume deficit Hypovolemia: Sign and Symptoms Skin turgor is diminished Skin may be warm and dry with mild deficit Skin may be cool and moist with severe deficit Skin may appear dry and wrinkled Oral mucous membranes will be dry, sticky, pastelike coating and the tongue may be furrowed Patient C/O thirst Eyes: soft, sunken Lab data: ↑ H & H; BUN; 10 Nursing Care Plan Therapeutic Interventions Restore fluid and electrolyte balance IVs and blood products as ordered; small, frequent drinks by mouth Daily weights to monitor progress of fluid replacement Loss or gain of 2.2 lbs is equal to 1 L of fluid I & O, hourly outputs Two most important assessments: HR & Output Avoid hypertonic solutions Promote comfort Frequent skin care Position: change q hr to relieve pressure meds as ordered: antiemetics, antidiarrheal 11 Nursing Care Plan Therapeutic Interventions Prevent physical injury Risk for falls due to orthostatic hypotension, dysrhythmia, muscle weakness, gait stability and level of alertness. Frequent mouth care Dry mucous membrane due to dehydration Monitor IV flow rate Observe for circulatory overload (↑ pulse, ↑ HR) Pulmonary edema (SOB) Monitor vital signs BP should be rising, ↑ LOC: more alert 12 ECF Volume excess Hypervolemia • Causes – Excessive intake of fluids – Abnormal retention of fluids • Heart failure • Renal failure – Long-term corticosteroid therapy 13 ECF Volume excess Hypervolemia: Signs and symptoms Cardiovascular Changes ↑ Pulse: full and bounding Full peripheral pulses Distended neck veins ↑ BP Other Changes -Urine; polyuria, nocturia -Lab data ↓ Hematocrit, BUN Respiratory Changes ↑ respiratory rate Shallow respirations ↑ dyspnea with exertion or in the supine position Pulmonary congestion and pulmonary edema SOB Irritative cough Moist crackles 14 ECF Volume excess Hypervolemia: Signs and symptoms Neurologic changes Altered LOC Visual disturbances Skeletal muscle weakness Paresthesias Cerebral edema Headache Confusion Lethargy Diminished reflexes Seizures, coma Skin Edematous may feel cool Skin may feel taut and hard Edema-eyelids, facial, dependent (sacrum), pitting, peripheral extremities GI Changes Increased motility Enlarged liver 15 Nursing Care Plan Therapeutic Interventions Maintain oxygen to all cells Position: sim-Fowler’s or Fowler’s to facilitate improved gas exchange. Vital signs; q 4 hrs and PRN Tachycardia ↑ BP (overload) and ↓ BP (fluid deficit) Fluid restriction: I & O Promote excretion of excess fluid Meds as ordered: diuretics Monitor electrolytes, esp. Mg and K 16 Nursing Care Plan Therapeutic Interventions Obtain/maintain fluid balance Wt gain is the best indicator of fluid retention and overload Weight daily; 2.2 lbs = 1 Liter (1000 ml) Measure: all edematous parts, abdominal girth, I & O: fluid restriction Limit fluids by mouth, IVs per doctors orders Strict monitoring of IV fluids Prevent tissue injury Skin and mouth care as needed Evaluate feet for edema and discoloration when client is OOB Observe suture line on surgical clients (Potential for evisceration due to excess fluid retention) 17 Functions of Sodium • Regulates osmolality – ICF: 14 mmol/L & ECF: 135-145 mmol/L • Helps maintain blood pressure by balancing the volume of water in the body • Works with other electrolytes to promote nerves, muscles and other body tissues to work properly. 18 Hypernatremia Water loss: Causes Inadequate water intake Unconscious or cognitively impaired individuals NPO status Excessive water loss ↑ insensible water loss High fever Diuretic therapy Watery diarrhea Disease states Uncontrolled diabetes mellitus Water loss: Signs and Symptoms • Restlessness, agitation, twitching, confusion • Seizures*, Coma • Intense thirst • Dry, swollen tongue • Sticky mucous membranes • Weight loss • Weakness, lethargy • Postural hypotension 19 Hypernatremia Na gain: Causes Na intake IV fluids: hypertonic NaCl, excessive isotonic NaCl Hypertonic tube feeding with out water supplement Use of Na containing drugs corticosteroids Diseases Renal failure Na gain: Signs and Symptoms • Restlessness, agitation, twitching • Seizures, Coma • Intense thirst • Flushed skin • Weight gain • Peripheral and pulmonary edema • ↑ BP 20 Hyponatremia • Dilutional (↑ ECF Volume) Causes – Use of hypotonic irrigation solution – Tap water enemas – Excessive water gain • Excessive hypotonic IV fluid Dilutional (↑ ECF Volume) Signs and Symptoms Headache, apathy, confusion Nausea, vomiting, anorexia Lethargy Weakness Muscle spasms, seizures, coma Diarrhea, Abdominal cramps Weight gain ↑ BP 21 Hyponatremia Na Loss: Causes GI Vomiting Diarrhea NG suctioning NPO Status Kidney Diuretic Skin • Burns • Wounds • Excessive diaphoresis Na Loss: Signs and Symptoms Irritability, apprehension, confusion Dizziness Personality changes Tremors, seizures, coma Dry mucous membranes Postural hypotension Tachycardia, thread pulse Cold & clammy skin 22 Functions of Potassium • Maintains fluid balance in the cells – Contributes to intracellular osmotic pressure • Direct effect on excitability of nerves and muscles – Skeletal, cardiac, and smooth muscle contraction • Regulates glucose use and storage 23 Hyperkalemia Causes • Most cases of hyperkalemia occur in hospitalized patients and in those undergoing medical treatment. • Those at greatest risk for hyperkalemia are – Chronically ill patients – Debilitated patients – Older adult 24 Hyperkalemia Causes Actual hyperkalemia • Excess potassium Intake – Excessive or rapid parenteral administration Relative hyperkalemia • Shift of potassium Out of Cells – Acidosis – Crushing injury – Tissue catabolism (fever, sepsis, burns) 25 Hyperkalemia Causes • Failure to Eliminate Potassium – Renal disease – Potassium-sparing diuretics – ACE inhibitors 26 Hyperkalemia Signs and Symptoms Clinical Manifestations Irritability Abdominal cramping, diarrhea Weakness of lower extremities Irregular pulse Cardiac arrest if hyperkalemia sudden or severe Electrocardiogram Changes • Ventricular fibrillation • Ventricular standstill 27 Hypokalemia Causes • Potassium Loss – GI losses: diarrhea, vomiting, fistulas, NG suction, NPO status – Renal losses: diuretics, – Skin losses: diaphoresis – Dialysis • Shift of Potassium into Cells – Alkalosis 28 Hypokalemia Causes • Lack of Potassium Intake – Starvation – Diet low in K – Failure to include K in parenteral fluids if NPO – TPN 29 Hypokalemia Signs and Symptoms Clinical Manifestations Fatigue Muscle weakness, leg cramps Nausea, vomiting, paralytic ileus Soft, flabby muscles Paresthesias, decreased reflexes Weak, irregular pulse Electrocardiogram Changes • Ventricular dysrhythmias (e.g., PVCs) • Bradycardia 30 Hypokalemia Medical Management Administration of KCl supplements K may be given orally (K chloride, K gluconate, K citrate) or IV KCl should be administered IV at a rate of 10 to 20 mEq/L over an hour. Rapid infusion could cause cardiac arrest IV K solutions irritate veins and cause phlebitis. Check IV site q 2 hrs. Discontinue IV if infiltrate to prevent necrotic and slough of tissue 31 Functions of Calcium • Helps maintain muscle tone • Contributes to regulation of blood pressure by maintaining cardiac contractility • Necessary for nerve transmission and contraction of skeletal and cardiac muscle 32 Hypercalcemia Causes Increased Total Calcium Prolonged immobilization Thiazide diuretics Dehydration Renal failure 33 Hypercalcemia Signs and Symptoms Clinical Manifestations Lethargy, weakness Depressed reflexes (DTR) Decreased memory Confusion, personality changes, psychosis Anorexia, nausea, vomiting, constipation Bone pain, fractures Electrocardiogram Changes • Ventricular dysrhythmias • Hypertension 34 Hypocalcemia Causes Decreased Total Calcium Chronic renal failure Loop diuretics (e.g., furosemide [Lasix]) Chronic alcoholism Diarrhea Decreased Ionized Calcium Excess administration of citrated blood 35 Hypocalcemia Signs and Symptoms Clinical Manifestations Easy fatigability Depression, anxiety, confusion Numbness and tingling in extremities and region around mouth • Hyperreflexia, muscle cramps • Chvostek’s sign & Trousseau’s sign • Laryngeal spasm • Tetany, seizures Electrocardiogram Changes • Ventricular tachycardia 36 Functions of Magnesium • Cofactor in clotting cascade • muscular irritability and contractions • Maintains strong and healthy bones 37 Hypermagnesemia Causes Renal failure Diabetes Mellitus Clients who ingest large amounts of Mgcontaining antacids such as Tums, Maalox, Mylanta, or laxatives such as MOM are also in ↑ risk for developing hypermagnesemia 38 Hypermagnesemia Signs and Symptoms – Bradycardia and hypotension – Severe hypermagnesemia: cardiac arrest – Drowsy or lethargic – Coma – Deep tendon reflexes are reduced or absent – Skeletal muscle contractions become progressively weaker and finally stop 39 Hypomagnesaemia Causes • Malabsorption disorders – Inflammatory bowel disease (IBD) – Bowel resection – Bariatric population who undergoes gastric bypass surgery • Alcoholism • Prolonged diarrhea • Draining GI fistulas • Diuretics 40 Hypomagnesaemia Signs and Symptoms • Confusion • Hyperactive deep tendon reflexes • Tremors • Seizures • Neuromuscular changes – Hyperactive deep tendon reflexes – Numbness and tingling – Painful muscle contractions – Monitor for positive Chvostek’s and Trousseau’s signs (hypocalemia may 41 Case Study • Susan Reynolds, a 42-year-old married accountant, has just been admitted to the acute care unit with a history of nausea, loss of appetite, and vomiting and diarrhea for 7 days. She feels her symptoms are related to “bad food” she had on her recent business trip. Past medical history includes hypertension controlled by furosemide (Lasix) 40 mg by mouth once a day and a no-salt-added diet. Discussion • What is Mrs. Reynolds at risk for? • What will you assess? • How does Lasix factor into this situation? – What lab should be monitored when administering this medication? 43 • Mrs. Reynolds’ electrolytes are out of balance due to the vomiting and diarrhea. Lasix therapy compounds this issue because Lasix is a diuretic that causes fluid loss. • Reference: Pg. 887 44 Case Study (cont’d) • Mrs. Reynolds’ physician has admitted her for observation and has obtained a blood sample for electrolyte levels, CBC, and an ECG. Orders include nothing by mouth, an IV infusion of 0.9% saline at 125 mL/hr, intake and output (I&O) recordings, and vital signs every 4 hours, in addition to daily weights. • What assessment activities do you anticipate Robert will perform? What should Robert Assess? • Ask Mrs. Reynolds to describe her nausea and what accompanying signs and symptoms she is experiencing. • Conduct an examination of GI and urinary function. • Assess Mrs. Reynolds’ vital signs. • Assess Mrs. Reynolds’ skin and mucous membranes for indicators of dehydration. • Evaluate Mrs. Reynolds’ laboratory values and ECG results. • Reference: Pg. 895 46 Nursing Knowledge Base • Use the scientific knowledge base in clinical decision making to provide safe, optimal fluid therapy. • Apply knowledge of risk factors for fluid imbalances and physiology of normal aging when assessing older adults, knowing that this age group is at high risk for fluid imbalances. • Ask questions to elicit risk factors for fluid, electrolyte, and acid-base imbalances. • Perform clinical assessments for signs and symptoms of these imbalances. Nursing Process: Assessment • Nursing history – Age: very young and old at risk – Environment: excessively hot? – Dietary intake: fluids, salt, foods rich in potassium, calcium, and magnesium – Lifestyle: alcohol intake history – Medications: include over-the-counter (OTC) and herbal, in addition to prescription medications Nursing Process: Assessment (cont’d) • Medical history – Recent surgery (physiological stress) – Gastrointestinal output – Acute illness or trauma • Respiratory disorders • Burns • Trauma – Chronic illness • Cancer • Heart failure • Oliguric renal disease Physical Assessment • Daily weights – Indicator of fluid status – Use same conditions. • Fluid intake and output (I&O) – 24-hour I&O: compare intake versus output – Intake includes all liquids eaten, drunk, or received through IV. – Output = Urine, diarrhea, vomitus, gastric suction, wound drainage • Laboratory studies Case Study (cont’d) • Mrs. Reynolds states that she has no appetite, is nauseous, and has been vomiting and has had diarrhea for 7 days. • Bowel sounds are hyperactive in all four quadrants. The patient has had only two loose stools since midnight. She voids with difficulty, with dark yellow urine. Her 24-hour intake was 1850 mL; her output was 2200 mL (of which urine was only 1000 mL). • Temperature 99.6° F; pulse 100 bpm; BP 110/60 mm Hg with no changes when standing What’s wrong? • The assessment findings indicate that Mrs. Reynolds is dehydrated. • Reference: Pg. 895 52 Case Study (cont’d) • Mrs. Reynolds’ laboratory results: – Hematocrit 44% (suggesting hypovolemia) – Potassium 3.6 mEq/L and sodium 138 mEq/L (both low normal because of prolonged vomiting and diarrhea) – Electrocardiogram (ECG) showed normal sinus rhythm. Nursing Diagnosis ?????? ?????? ?????? Possible nursing diagnoses for Mrs. Reynolds include: 1. Risk for electrolyte imbalance 2. Fluid volume deficit 3. Impaired oral mucous membrane 4. Deficient fluid volume related to excessive diarrhea, vomiting, and use of potassiumwasting diuretic Reference: Pg. 900 55 Case Study (cont’d) • Nursing diagnosis: Deficient fluid volume related to excessive diarrhea, vomiting, and use of potassium-wasting diuretic GOALS – Mrs. Reynolds’ fluid volume will return to normal by time of discharge. – Mrs. Reynolds will achieve normal electrolyte balance by discharge. – What are 3 other goals? • 1. • 2. • 3. 57 Planning • Goals and outcomes • Setting priorities • Collaborative care Expected Outcomes ????????????? 59 Case Study (cont’d) • Fluid balance – – – – Urine output will equal intake of ~1500 mL in 2 days. Mucous membranes will be moist in 24 hours. Skin turgor will return to normal within 24 hours. Daily weights will not vary by more than 2 lbs over the next 2 days. • Electrolyte and acid-base balance – Serum electrolyte and blood counts will be within normal limits within 48 hours. – Mrs. Reynolds will not have any nausea or vomiting in 24 hours. Nursing Interventions • Interventions for electrolyte imbalances – Support prescribed medical therapies – Aim to reverse the existing acid-base imbalance – Provide for patient safety Interventions & Rationales ????????? 62 Interventions • Administer IV fluids (0.9% normal saline) at 125 mL/hr. – 1. Replacement of body fluid restores blood volume and normal serum electrolyte levels; an isotonic solution expands the body’s intravascular fluid volume without causing a fluid shift from one compartment to another. • Provide patient with an additional 480 mL of noncaffeinated oral fluids every 8 hours. – 2. Pepto-Bismol is an antidiarrheal to inhibit GI secretions, stimulate absorption of fluid and electrolytes, inhibit intestinal inflammation, and suppress the growth of Helicobacter pylori. Interventions and Rationales 1. Maintain accurate I&O measurements. a. I&O documents hydration and fluid balance for directing therapy. 2. Weigh Mrs. Reynolds daily; monitor trends. a. Daily weights provide reliable data of fluid balance. 3. Teach Mrs. Reynolds and family about specific dietary modification (potassium-rich foods). a. Furosemide (Lasix) is a potassium-wasting diuretic. The body does not store potassium, thus requiring dietary supplements rich in potassium. Reference: Pg. 903 64 Implementation • Health promotion – Fluid replacement education – Teach patients with chronic conditions about risk factors and signs and symptoms of imbalances. • Acute care – Enteral replacement of fluids – Restriction of fluids – Parenteral replacement of fluids and electrolytes • Total parenteral nutrition • Crystalloids (electrolytes) • Colloids (blood and blood components) Implementation • Restorative care – Home intravenous therapy – Nutrition support – Medication safety • Medications • OTC drugs • Herbal preparations Case Study (cont’d) • Nursing actions: – Monitor electrolyte levels and daily weights. – Inspect oral mucous membranes; assess skin turgor. – Evaluate I&O trends during next 48 hours. • Findings – Serum electrolyte levels: potassium 4.0 mEq/L and sodium 140 mEq/L – Mucous membranes remain dry; skin turgor normal – Mrs. Reynolds’ 24-hour intake is 2800 mL, and output is 2200 mL with 1800 mL urine. Urine specific gravity is 1.025, and weight has returned to 143 lb. Evaluation 1. Are the goals met? 2. How do we know? Evaluation • Robert is encouraged by Mrs. Reynolds’ progress. He discusses sources of potassium in the diet and writes this documentation note: • “Denies nausea and reports feeling better. No diarrheal stool since yesterday afternoon around 3 p.m. On inspection, oral mucosa remains dry, without lesions or inflammation. Skin turgor is normal. Bowel sounds are normal in all four quadrants, abdomen soft to palpation. IV of 0.9% normal saline is infusing in left cephalic vein in forearm at 40 mL/hr per MD order. No tenderness or inflammation at IV site. Is able to identify five food sources for potassium to include in diet. Is resting comfortably, out of bed in a chair, ate all of breakfast. Will continue to monitor.” • Reference: Pg. 914 69