危重儿液体管理课件.ppt

Fluid and Electrolyte Emergencies in Critically Ill Children,Richard T.Blaszak,M.D.Stephen M.Schexnayder,M.D.,Objectives,At the end of this presentation learners will be able to:1)Recognize common fluid and electrolyte disorders in critically ill children2)List a diagnostic strategy for these disorders3)Apply appropriate management principles,Case Study#1,HPI:A 3 month-old is in the PICU for shock following a two day history of fever and irritability.Blood and CSF cultures are positive for Streptococcus pneumoniae.Hospital course:Decreasing urine output(0.5 ml/kg/hr)over the last 24 hours.,Case Study#1,What is your differential diagnosis?What diagnostic studies would you order?,Case Study#1Differential diagnosis,Oliguria1)Pre-Renal(decreased effective renal blood flow)Diminished intravascular volume,cardiac dysfunction,vasodilitation2)Post-RenalOutlet obstruction(intrinsic vs.extrinsic),foley catheter occlusion3)RenalAcute tubular necrosis,acute renal failure,SIADH,.,Case Study#1Laboratory studies,Serum studiesSodium 126 mEq/LBUN 4 mg/dLChloride 98 mEq/LCreatinine 0.4 mg/dLPotassium 3.7 mEq/LGlucose 129 mg/dLBicarbonate 25 mEq/LOsmolality 260 mosmol/kgUrine studiesSpecific gravity 1.025Sodium 58 mEq/LOsmolality 645 mosmol/kgFeNa 2.4%What are the primary abnormalities?,Case Study#1Laboratory studies,Major abnormalities1)Hyponatremia2)Oliguria(inappropriately concentrated urine)What is the most likely explanation for these findings?,Case Study#1 Syndrome of Inappropriate Antidiuretic Hormone(SIADH),Variable etiologyTraumaInfectionPsychosisMalignancyMedicationsDiabetic ketoacidosisCNS disordersPositive pressure ventilation“Stress”,Case Study#1 SIADH,ManifestationsBy definition,“inappropriate”implies having excluded normal physiologic reasons for release of ADH:1)In response to hypertonicity.2)In response to life threatening hypotension.HyponatremiaOliguriaConcentrated urineelevated urine specific gravity“inappropriately”high urine osmolality in face of hyponatremiaNormal to high urine sodium excretion,Case Study#1 SIADH,DiagnosisCritical level of suspicion.Demonstration of inappropriately concentrated urine in face of hyponatremia urine osmolality,SG,urine sodium excretion(FeNa)Be certain to exclude normal physiologic release of ADH Frequently secondary to decreased perfusion Serum sodium,urine osmolality,urine sodium excretion(low FeNa)consistent with dehydration or diminished renal blood flow.Look at patient more closely!,Case Study#1 SIADH,TreatmentFluid restriction.50-75%of maintenance requirements,be certain to include oral intake.Daily weights.,Case Study#1The saga continues.,Hospital course:Four hours after beginning fluid restriction,you are called because the patient is having a generalized seizure.There is no response to two doses of IV lorazepam(Ativan)and a loading dose of fosphenytoin(Cerebyx)What is the most likely explanation?,Case Study#1The saga continues,Seizure1)Worsening hyponatremia2)Intracranial event3)Meningitis4)Other electrolyte disturbance5)Medication6)HypertensionWhat diagnostic studies would you order?,Case Study#1The saga continues,Stat labs:Sodium 117 mEq/LWhat would you do now?,Case Study#1 Hyponatremic seizure,Treatment Hypertonic saline(3%NaCl)infusionTo correct sodium to 125 mEq/L,the deficit is equal to(0.6)(weightkg)(125-measured sodium)(0.6)(8)(125-117)=38.4 mEqBecause patient is symptomatic with seizures,immediately increase serum sodium by 5 mEq/LmEq sodium=(0.6)(8 kg)(5)=24 mEq3%NaCl=0.5 mEq/L,therefore 24 mEq bolus=48 mls,followed by slow infusion of remaining 14.4 mEq(29 mls)over next several hours,Case Study#2,HPI:A 5 month-old girl presents with a one day history of irritability and fever.Mother reports three days of“bad”vomiting and diarrhea.Home meds:Acetaminophen and ibuprofen for feverPE:BP 70/40,HR 200,R 60,T38.3 C.Irritable,sunken eyes and fontanelle,skin feels like Pillsbury Dough Boy,Case Study#2,No one can obtain IV access after 15 minutes,what would you do now?,Case Study#2,Place intraosseous lineBolus 40 ml/kg of isotonic salineReassessment(HR 170,RR 40,BP 75/40)Serum studiesSodium 164 mEq/LBUN 75 mg/dLChloride 139 mEq/LCreatinine 3.1 mg/dLPotassium 5.5 mEq/LGlucose 101 mg/dLBicarbonate 12 mEq/LpH 7.07 pCO2 11 pO2 121 HCO3 8,Case Study#2,What is the most likely explanation of this patients acidosis?,Case Study#2Metabolic acidosis and the anion gap,Anion GapSodium-(chloride+bicarbonate)Normal 12+/-2 meq/LElevated anion gap consistent with excess acidNormal anion gap consistent with excess loss of base 164-(139+12)=13,1.Normal gap,2.Increased gap,Renal“HCO3”losses,2.GI“HCO3”losses,Proximal RTA Distal RTA,Diarrhea,1.Acid prod,2.Acid elimination,LactateDKAKetosisToxins Alcohols Salicylates Iron,Renal disease,Case Study#2Metabolic acidosis and the anion gap,Case Study#3,HPI:A five year old(18 kg)boy was involved in a a motor vehicle accident two days ago.He sustained an isolated head injury with intraventricular hemorrhage and multiple large cerebral contusions.Three hours ago,he had an episode of severe intracranial hypertension(ICP 90mm Hg,MAP 50mm Hg,requiring volume plus epinephrine infusion for hypotension.Over the last two hours,his urine output has increased to 130-150 ml/hour(8ml/kg/hr).What is your differential diagnosis?What test would you order?,Case Study#3Differential diagnosis,Polyuria1)Central diabetes insipidusDeficient ADH secretion(idiopathic,trauma,pituitary surgery,hypoxic ischemic encephalopathy)2)Nephrogenic diabetes insipidusRenal resistance to ADH(X-linked hereditary,chronic lithium,hypercalcemia,.)3)Primary polydipsia(psychogenic)Primary increase in water intake(psychiatric),occasionally hypothalamic lesion affecting thirst center4)Solute diuresisDiuretics(lasix,mannitol,.),glucosuria,high protein diets,post-obstructive uropathy,resolving ATN,.,Case Study#3Laboratory studies,Serum studiesSodium 155 mEq/LBUN 13 mg/dLChloride 114 mEq/LCreatinine 0.6 mg/dLPotassium 4.2 mEq/LGlucose 86 mg/dLBicarbonate 22 mEq/LSerum osmolality:320 mosmol/kgOtherUrine specific gravity 1.005,no glucose.Urine osmolality:160 mosmol/kgWhat are the main abnormalities?,Case Study#3Laboratory studies,Major abnormalities1)Hypernatremia2)Polyuria(inappropriately dilute urine)What is the most likely explanation?,Case Study#3Diabetes Insipidus,DiagnosisCentral Diabetes insipidus1)Polyuria2)Inappropriately dilute urine(urine osmolality serum osmolality)May be see with midline defectsFrequently occurs in brain dead patientsWhat should you do to treat this child?,Case Study#3Diabetes Insipidus,Treatment Acute:Vasopressin infusion-begin with 0.5 milliunits/kg/hour,double every 15-30 minutes until urine flow controlledChronic:DDAVP(desmopressin)WarningClosely monitor for development of hyponatremia,Case Study#4,HPI:A six year old,25 kg,boy with severe asthma(S/P ECMO for a previous exacerbation)presents with a two day history of severe vomiting and diarrhea to the Emergency Department.Home meds:Albuterol MDI two puffs QID,Salmeterol MDI two puffs BID,Prednisone 10mg daily,Fluticasone 220 mcg two puffs BIDPE:BP 70/40,HR 168,R 40,T39.0 C.He is very lethargic(GCS 11).Poor perfusion with cool extremities,mottling,and delayed capillary refill,otherwise no specific system abnormalities.,Case Study#4,What is your differential diagnosis?What diagnostic studies would you order?,Case Study#4Differential diagnosis,Shock1)CardiogenicMyocarditisPericardial effusion2)HypovolemicHemorrhage,excessive GI losses,“3rd spacing”(burns,sepsis)3)DistributiveSepsis,anaphylaxis,Case Study#4Laboratory studies,Serum studiesSodium 130 mEq/LBUN 43 mg/dLChloride 99 mEq/LCreatinine 0.6 mg/dLPotassium 5.7 mEq/LGlucose 48 mg/dLBicarbonate 12 mEq/LOtherWBC:13k(60%P,30%L),HCT 35%,PLT 223kChest radiograph:no abnormalitiesWhat are the electrolyte abnormalities?,Case Study#4Diagnosis,Major abnormalities1)Hyponatremic dehydration2)Hypoglycemia3)Hyperkalemia,mild4)Acidosis5)AzotemiaWhat is the most likely explanation for these findings?,Case Study#4 Adrenal Insufficiency,1o adrenal insufficiency(Addisons disease)Adrenal gland destruction/dysfunction(ie.autoimmune,hemorrhagic)most common in infants 5-15 days old 2nd adrenal insufficiency ACTH deficiency(ie.panhypopituitarism or isolated ACTH)“Tertiary”or“iatrogenic”Suppression of hypothalamic-pituitary-adrenal axis(ie.chronic steroid use),Case Study#4 Adrenal Insufficiency,ManifestationsMajor hormonal factor precipitating crisis is mineralcorticoid deficiency,not glucocorticoid.Dehydration,hypotension,shock out of proportion to severity of illnessNausea,vomiting,abdominal pain,weakness,tiredness,fatigue,anorexiaUnexplained feverHypoglycemia(more common in children and tertiary)Hyponatremia,hyperkalemia,azotemia,Case Study#4 Adrenal Insufficiency,DiagnosisCritical level of suspicion in all patients with shock1)Demonstration of inappropriately low cortisol secretionBasal morning level vs.random“stress”level2)Determine whether cortisol deficiency dependent or independent of ACTH secretion.ACTH,cortisol 1o adrenal insufficiency ACTH,cortisol 2nd or tertiary insufficiency 3)Seek a treatable cause,Case Study#4 Adrenal Insufficiency,What should you do to treat this child?,Case Study#4 Adrenal Insufficiency,TreatmentDo not wait for confirmatory labsFluid resuscitation-isotonic crystalloidTreat hypoglycemiaGlucocorticoid replacement-hydrocortisone in stress doses-25-50 mg/m2(1-2 mg/kg)IVConsider mineralocorticoid(Florinef),Case Study#5,HPI:An eight month old infant with autosomal recessive polycystic kidney disease presents with irritability.She is on nightly peritoneal dialysis at home.The lab calls a panic potassium value of 7.1 meq/L.The tech says it is not hemolyzed.What do you do now?,Case Study#5Hyperkalemia,TreatmentImmediately repeat serum potassium.Do not wait for confirmatory labs especially if EKG changes present.Anticipatory Stop potassium administration including feeds,Cardiac Monitor,What is this rhythm?What is your immediate treatment?,Case Study#5Hyperkalemia,Treatment(cont)Control effectsAntagonism of membrane actions of potassiumCalcium chloride 10-20 mg/kg over 5 minutes;may repeat x2Shift potassium intracellularlyGlucose 1 gm/kg plus 0.1 unit/kg regular insulinAlkalinize(increase ventilator rate;Sodium bicarbonate 1 mEq/kg IV)Inhaled 2 adrenergic agonist(albuterol)Removal of potassium from the bodyLoop/thiazide diureticsCation exchange resin:sodium polstyrene sulfonate(Kayexelate)1 gm/kg PO or PR(or both)Dialysis,Case Study#6,HPI:A three year old boy is recovering from septic shock.He received 150 ml/kg in fluid boluses in the first 24 hours and has anasarca.You begin him on a bumetanide infusion(Bumex)for diuresis.He develops severe weakness and begins to hypoventilate.You notice unifocal premature ventricular beats on his cardiac monitor.What is your differential diagnosis?What tests would you order?,Case Study#6Laboratory studies,Serum studiesSodium 134 mEq/LBUN 11 mg/dLChloride 98 mEq/LCreatinine 0.4 mg/dLPotassium 2.4 mEq/LCalcium 9.2 mg/dLBicarbonate 27 mEq/LPhosphorus 3.2 mg/dLOtherEKG:Unifocal PVCsWhat is the main abnormality?,Case Study#6Laboratory studies,Major abnormality1)HypokalemiaWhat would you do now?,Case Study#6Hypokalemia,Treatment Oral Safest,although solutions may cause diarrheaIVPeripheral:do not exceed 40-50 mEq/L potassium-Avoid temptation to rapidly bolusCentral:0.5-1 mEq/kg over 1-3 hours,depending on severityReplace magnesium also if low(25-50 mg/kg MgSO4),Summary,Disorders of sodium,water,and potassium regulation are common in critically ill childrenDiagnostic approach must be considered carefully for each patientStrict attention to detail is important in providing safe and effective therapy,