Presentation on theme: "Alterations in Fluid, Electrolyte and Acid-Base Balance"— Presentation transcript:
1Alterations in Fluid, Electrolyte and Acid-Base Balance Ball & BindlerDonna Hills EdD APN
2Pediatric Differences ECF/ICF ratio varies with ageNeonates and infants have proportionately larger ECF volInfants: high daily fluid requirement with little fluid reserve; this makes the infant vulnerable to dehydration.
4Fluid Loss; Infants and <2yr. excretion is via the urine, feces, lungs and skinhave greater daily fluid loss than older childmore dependent upon adequate intakegreater about of skin surface (BSA), therefore greater insensible loss.respiratory and metabolic rates are highertherefore, dehydrate more rapidly
6Mechanism to Restore balance kidney: conserves water, regulates electrolyte excretion<2yr kidneys immatureless able to conserve or excrete water and solutes effectivelygreater risk for acid/base imbalancesWill use the SG norm:
7Fluid Volume Imbalances Dehydration: loss of ECF fluid and sodium.Caused by: vomiting, diarrhea, hemorrhage, burns, NG suction.Manifested by wt loss, poor skin turgor, dry mucous memb., VS changes, sunken fontanelFluid overload: excess ECF fluid and excess interstitial fluid volume with edema.Causes: fluid overload, CHF.Manifested by wt.gain, puffy face and extremities, enlarged liver.
8Nursing Considerations How can the nurse determine if the child is mildly dehydrated vs moderately dehydrated?
9Mild Dehydration: by history. hard to detect because the child may be alert, have moist mucous membranes and normal skin turgor.Wt loss may be up to 5% of body weight.The infant might be irritable; the older child might be thirstyvital signs will probably be normalCapillary refill will most likely be normalUrine output may be normal or sl less
10Moderate Dehydrationdry mucous membranes; delayed cap refill >2 sec; Wt loss 6-9% of body weightirritable, lethargic, unable to play, restlessdecreased urinary output: <1ml/kg/hr; dark urine with SG > (in child >2yr)Sunken fontanelHR increased, BP decreased. Postural vital signs
11Severe Dehydration wt loss > 10% body weight lethargic/comatose rapid weak pulse with BP low or undetectable; RR variable and labored.dry mucous membranes/parched; sunken fontaneldecr or absent urinary output.Cap refill >4sec
12Types of Dehydration and Sodium Loss Sodium may be:LowHighOr normal
13Isotonic Dehydration or Isonatremic Dehydration Loss of sodium and water are in proportionMost of fluid lost is from extracellular componentSerum sodium is normal ( mEq/L) Harriet Lane Handbook, 2000.Most practitioners consider below 135 and above 148 a more conservative parameter ( )Most common form of dehydration in young children from vomiting and diarrhea.
14Hypotonic or Hyponatremic Dehydration Greater loss of sodium than waterSerum sodium below normalCompensatory shift of fluids from extracellular to intracellular makes extracellular dehydration worse.Caused by severe and prolonged vomiting and diarrhea, burns, renal disease. Also by treatment of dehydration with IV fluids without electrolytes.
15Hypertonic or Hypernatremic Dehydration Greater loss of water than sodiumSerum sodium is elevatedCompensatory shift from intracellular to extracellular which masks the severity of water loss (dehydration) delaying signs and symptoms until condition is quite serious.Caused by concentrated IV fluids or tube feedings.
16Rotavirus Common viral form of diarrhea All ages but 3 mo-2yrs most commonFecal/oral routeVirus remains active;10 days on hard, dry surfaces4 hrs on human hands1 wk on wet areas
17Rotavirus (cont.) Incubation period 1-3 days Symptoms: mild/mod fever, stomach ache, frequent watery stools (20/day)Treatment: prevention! Hand washing and isolation of the infected child.Fluid rehydration for diarrhea, advanced to bland diet for older childrenBreast milk for the infant who BF
18Clinical Management for Dehydration Blood may be drawn to assess electrolytes, BUN and Creatinine levelsan IV may be placed the same timeOral Rehydration Solution is the treatment of choice for mild-moderate dehydration1-3 tsp of ORS every 10-15min to start (even if vomits some)50ml/Kg/Hr is the goal for rehydration.
19Why are drinks high in glucose avoided during rehydration? Simple sugars increases the osmotic effect in the intestine by pulling water into the colon, thereby increasing diarrhea and subsequent fluid/electrolyte lossDrinks high in glucose: apple juice, sodas, jello water.
21Recommended foods during rehydration progression: starches, cooked fruits & vegetables, soups, yogurt, formula, breast milk.BRAT diet used to be recommended, but recent research has shown no difference than return to normal diet with some attention to lactose containing foods, depending upon the child’s response.
22IV TherapyUsed for severe dehydration or in the child who will not/cannot tolerate ORSHalf 24hr maintenance plus replacement given within first 6-8hr (in ER) to rapidly expand the intravascular space. Usually a normal saline bolus.slower IV rate for the remainder of the first 24hrsnurse records IV vol infused hourly
23Rehydration and IV solution Why is the child initially rehydrated with a normal saline bolus and not an IV solution with potassium?Potassium is only added to an IV after the patient has voided to avoid hyperkalemia in a child with little or no urinary output
25Which of the following IV solutions replaces Sodium? D5 WLactated RingersNormal SalineD5 ½ NS
26Answer:All but D5 WSee IV solutions table B & B p. 733
27Calculation of intravenous fluid needs: maintenance see pg 735 B&B, Box 23-5.For the 1st 10 Kg, replace at 100ml/Kgfor the second 10 Kg, replace at 50ml/Kgfor >20kg, replace at 20ml/Kg
28Example of Maintenance Fluid Calculation Your patient is a 10 yr old weighing 35 Kg. You want to determine this patient’s 24hr maintenance fluid needs:for the first 10 Kg give 100ml/Kg = 1000mlfor the second 10 Kg: ml/Kg = 500mlfor the remaining 15 Kg (35-20Kg) , replace at 20 ml/Kg = 20 (15) = 300ml= 1800ml/day.
29How much fluid should this patient get per hour? 1800 ml / 24 hrs = 75 ml/hr.Therefore, if the patient were NPO and not taking in fluids from any other source, the IV should be running at 75ml/hr.If there is a deficit that also needs to be replaced, the IV rate may be slightly higher for a defined period of time.If the patient is receiving fluids from other sources, these need to be accounted as well
30Practice Problems for Calculating 24hr Fluid Maintenance and the hourly IV rate for: A 9 yr old patient who weighs 20 Kg.A 6 mo old baby who weighs 8 KgAn 24mo old toddler who weighs 18 KgA 3 yr old preschooler who weighs 28 KgAn 18 yr old who weighs 50 Kg9yr old wt 20 Kg = 1500ml/day6 mo old wt 8Kg= 800ml/day36mo old wt. 18 Kg= 1400ml/day3yr old wt 28Kg=1660ml/day18yr old wt 50Kg= 2100ml/dayAdult > 50Kg= 2-3L/day
33Clinical Assessment/Management of Edema assess dependent limbs if ambu or sacrum is lyingascites; periorbital edema; rings too tightpitting edema for degree of swellingdaily wt and strick I and Oelevation/change position Q2hr/ protect skin against breakdowndistraction to deal with discomfort and limitations of edema.
34Electrolyte Imbalances Electrolytes usually gained and lost in relatively equal amounts to maintain balanceImbalance caused by:Abnormal route of loss (vomiting/diarrhea) can disturb electrolyte balanceDisproportionate IV supplementationDisease states: renal dis.
35Hypernatremia Excess serum sodium in relation to water Causes: Too concentrated infant formulaNot enough water intakeClinical manif: thirst, lethary, confusionSeizures occur when rapid or is severe.SG concentratedLab test: serum sodiumTreatment: hypotonic IV solution
36Hyponatremia Excess water in relation to serum sodium Most common sodium imbalance in childrenCauses:Infants vulnerable to water intoxication:dilute form, excess pool water, poorly developed thirst mech so cont to drink and can’t excrete excess water.
37Hyponatremia (cont)Clinical manif: decreased level of consciousness d/t swelling of brain cells.Anorexia, headache, muscle weakness, decreased DTR’s, lethargy, confusion or coma.Seizures occur when rapid or severe.SG dilute:Lab tests: serum sodiumTreatment: hypertonic solution.
38Hyperkalemia Excess serum potassium Causes: excess K intake from IV overload, blood transfusion, rapid cell death (hemolytic crisis, large tumor destruction from chemo rx, massive trauma, metabolic acidosis from prolonged diarrhea and in DM when insulin levels are lowInsulin drives K back into the cellsdecreased K loss from Renal insufficiency
39Hyperkalemia (cont)Clinical manif: all are related to muscle dysfunction: hyperactivitiy of GI smooth muscle: intestinal cramping and diarrhea.Weak skeletal musclesLethargyCardiac arrhythmias (tachycardia, prolonged QRS, peaked T waves: also AV block and VTach).Lab test: serum potassiumTreatment: correct underlying condition (take K out of the IV)dialysis (peritoneal or hemo), Kayexalate (po or enema), K wasting diuretics, IV calcium, bicarbonate, insulin and glucose.Low potassium diet.
40Hypokalemia Decreased serum potassium Causes: diarrhea and vomiting, ingestion of large amts black licorice, diuretics, osmotic diuresis (glucose in urine as in DM), NPO without K replacement in IV, NG Sx, bulimia, insulin.Also in nephrotic syndrome, cirrhosis, Cushing Syndrome, CHF (to be covered elsewhere)
41Hypokalemia (cont) Clinical manif: muscle dysfunction Slowed GI smooth muscle resulting in abdominal distention, constipation and paralytic ileusSkeletal muscles are weak; may effect respiratory musclesCardiac arrhythmias: hypokalemia potentiates Digitoxin Toxicity.Lab test: serum potassiumTreatment: oral and/or IV potassium, diet rich in K.
42Hypercalcemia Excess calcium Needs vit D for efficient absorption; most of Ca is stored in the bones.Causes: bone tumors that cause bone destruction, chemo rx release Ca from the bones; immobilization causes loss from the bones (usually excreted) but if kidneys can’t clear it, hypercalcemia results, increased intake (milk-alkali syndrome).
43Hypercalcemia (cont)Clinical manif: Ca imbalances alter neuromuscular irritability with non-specific symptomsConstipation, anorexia, N/V, fatigue, skeletal muscle weakness, confusion, lethargy.Renal calculi, cardiac arrhythmiasHyperCa increases Na and K excretion leading to polyuria and polydipsia.Rx: serum Ca, Ionized Ca, fluids, Lasix, steroids, dialysis.
44Hypocalcemia Decreased serum calcium Causes: decreased intake of Ca and/or Vit D (adolescents are vulnerable d/t fad diets and the deficit cannot be made up later, increasing risk for osteoporosis).Limited exposure to sunlight, premature infants and dark skinned people at increased risk to inadeq. Vit D and therefore decreased Ca absorption.Parathyroid dysfunction, multiple transfusion (Citrate binds Calcium), steatorrhea (as in pancreatitis and Cystic Fibrosis) binds Calcium in the stool.
45Hypocalcemia (cont)Clinical Manif:acute situation related to increased muscular excitability: tetany. +Chvostek’s Sx, + Trousseau’s Sx.In children: Twitching, cramping, tingling around the mouth or fingers, carpal/pedal spasms.In infants: tremors, muscle twitches, brief tonic-clonic seizures, CHF.Laryngospasm, seizures and cardiac arrhythmias in severe situations.Chvostek’s Sx: p 755 tap the skin lightly in front of the ear (over the facial nerve), if the corner of the mouth draws up, d/t muscular contraction, + Chvostek’s Sx.Trousseau’s Sx: + if carpal spasm after BP cuff inflated ~ 3min.
46Hypocalcemia (cont 2)In children and adolescents, chronic hypocalcemia more common, manif. By spontaneous fractures. Lab tests: serum Ca; bone density study Rx: oral and/or IV Ca, Ca rich diet
47Hypermagnesemia Excess in Mg. Imbalances characterized by neuromuscular irritabilityCauses: impaired renal function, Mag Sulfate given perinatally to treat eclampsia, increased use of laxatives, enemas, antacids, IV fluid additives.
49Hypomagnesemia Decreased serum Mg. Stored in cells and bones Causes: prolonged NPO without replacement, chronic malnutrition, chronic diarrhea, short bowel syndrome, malabsorption syndromes, steatorrhea, multiple transfusions, prolonged NG Sx, some medications.
50Hypomagnesemia (cont) Clinical manif: increased neuromuscular excitability (tetany). Hyperactive reflexes, skeletal muscle cramps, twitching, tremors, cardiac arrhythmias, seizures.Lab: serum Mg along with Ca and K.Rx: po/IV Magnesium admin and treating underlying cause of imbalance.
51Critical Thinking: Clinical Evaluation of Fluid and Electrolyte Imbalance B & B p. 757How can you evaluate children appropriately for fluid and electrolyte imbalance without thinking through the clinical manifestations of every possible disorder, one after the other?3 paragraphs of text that review this concept and pull the content together with clinical application:1) risk factor assessment2) exam several body systems: cardiovascular, respiratory, neurological3) look for factors that alter intake, retention, and loss of fluids and electrolytes4) consider growth and development to realize problems most common to the age group.5) clinical assessment: wt, fluid balance, vascular volume (BP, HR), interstitial volume (edema?), mentation, DTR’s, muscle irritability, GI function, cardiac rhythm, assess electrolyte levels.
53Fluid and Electrolyte Worksheet Use the fluid and electrolyte worksheet to help review some of the major concepts of fluid and electrolyte imbalance.
54Acid Base Balance normal arterial blood pH: 7.35-7.43 (in general) Acidosis < 7.35 : too much acidAlkalotic > 7.43 : too little acidpCO2 reflects carbonic acid status:HCO3- reflects metabolic acid status:
55Respiratory Acidosis caused by decr respir effort build up of CO2 in the bloodpH decr or normal; pCO2 incr.Symptoms manifested: confusion, lethargy, HA, incr ICP, coma, tachycardia, arrhythmias
56Management of Respiratory Acidosis Incr ventilatory rategive O2intubateadm NaHCO3
57Clinical Conditions that cause Respir Acidosis conditions associated with decreased respiratory drive, impaired gas exchange/air trapping, ie:head trauma, general anesthesia, drug overdose, brain tumor, sleep apnea, mechanical under ventilation, asthma, croup/epiglottitis, CF, atelectasis, MD, pneumothorax.
58Respiratory Alkalosis caused by hyperventilationCO2 is being blown offpH incr : pCo2 decrSymptoms: dizziness, confusion, neuromuscular irritability, paresthesias in extremities and circumoral, muscle cramping, carpal or pedal spasms.
59Management of Resp. Alkalosis First determine if oxygenation is adequate, if not, you don’t want to slow the RR.Determine the cause and correct it:Causes of hypervent: hypoxemia, anxiety, pain, fever, ASA toxicity, meningitis/encephalitis, Gram - sepsis, mechanical overventilation.Ipecac is no longer recommended for treatment of ingestions.
60Metabolic Acidosis caused by a loss of bicarbonate (HCO3) therefore, is an incr of acids in the bloodpH decr or moving towards normalpCo2 decr ; HCO3 decrSymptoms: Kussmaul respirations = incr rate and depth as compensation (hyperventilation/acetone breath), confusion, hypotension, tissue hypoxia, cardiac arrhythmias, pulmonary edema.
61Management of Metabolic Acidosis Identify and treat underlying causeIn severe case may give IV NaHCO3 to incr pH, or insulin/glucose.Causes of MA for gain of acid: ingestion of ASA, antifreeze, oliguria, RF, HAL, DKA, starvation or ETOH KA, lactic acidosis (tissue hypoxia).Loss of HCO3: maple syrup urine disease, diarrhea, RF.
62Metabolic Alkalosis caused by loss of H+ or HCO3 retention HCO3 incr with probable incr in pH, incr pCO2.Symptoms:weak, dizzy, muscle cramps, twitching, tremors, slow shallow resp., disorientation, seizures.
63Management of Metabolic Alkalosis correct underlying cause; facilitate renal excretion of HCO3.admin NS, K+ if hypokalemic, replace loss of fluids, prec for Sz, monitor I and O and electrolytesCauses: prolonged vomiting, ingestion of lg quantities of bicarb, antacids, loss of NG fluids, hypokalemia from prolonged diuretic use, multiple blood transfusion with citrate.
64ABG Basic (Uncompensated) Analysis Resp Acidosis: low pH and high PaCO2Resp Alkalosis: incr pH and low PaCO2Metab Acidosis: low pH and nl PaCo2; decr HCO3Metab Alkalosis: high pH; nl PaCO2 ; high HCO3
65ABG Analysis with Compensation Resp Acidosis: HCO3 will incr, pH will approach nl; PaCO2 will still be increasedResp Alkalosis: HCO3 will decr, pH will approach nl; PaCO2 will still be decreasedMetab Acidosis: PaCO2 will decr, pH will approach nl; HCO3 will still be decreasedMetab Alkalosis: PaCO2 will incr, pH will approach nl; HCO3 will still be increased