FLUID AND ELECTROLYTE THERAPY IN A SURGICAL PATIENT.pptx

Fluid and electrolyte derangement and correction

1. FLUID AND ELECTROLYTE THERAPY IN THE SURGICAL PATIENT PROF. ALI NUHU DEPT. OF SURGERY COLLEGE OF MEDICAL SCIENCES UNIVERSITY OF MAIDUGUR 1

2. Need for I.V.F therapy, very important in surgical patients Poor fluid intake orally from: Diseases (peritonitis, intestinal obstruction) After surgical ops (intestinal resection, gastric surgery, ruptured viscus e.t.c .) Diarrhoea , vomiting, GOO All lose water and electrolytes, causing deficits 2 INTRODUCTION

3. Restore normal functional volumes of body fluids Normal concentrations of electrolytes Normal pH Correct fluid and electrolyte deficits An understanding of normal daily exchanges of water and electrolytes is needed 3 AIMS

4. TBW The adult male (70kg) TBW = 60% of body weight= 42L Adult female TBW= 50-55% of body weight because of more body fat TBW depends on age, sex, degree of obesity lower in aged and the obese 4 BODY FLUID COMPARMENTS

5. ICF = 40% Body wt ECF = 20% Body wt ECF: Intravascular fluid=5% Interstitial fluid = 15% Transcellular fluid e.g. GI, Eye, synovial fluid and CSF Full term neonates TBW = 75% of Bdy Wt With ECF = 35% of body weight 5 BODY FLUID COMPARTMENTS CTND

6. The Interstitial fluid is separated from plasma only by the capillary membrane Fluid may cross from compartment to compartment by osmosis which depends on solute gradient and by filtration, which is the result of a hydrostatic gradient ECF: carries nutrients from GIT and O 2 from the lungs to the tissues 6

7. 7 DISTRIBUTION OF ELECTROLYTES Cations ICF (concentration) K + Mg 2+ Na + 140mmol/L 15mmol/L 8mmol/L Anions Phosphate Proteins 26mmol/L 9mmol/L

8. CATIONS ECF (concentration) Na + K + Ca 2+ Mg 2+ 135-145mmol/L 3.6-5.2mmol/L 2.1-2.6mmol/L 0.7-0.9mmol/L ANIONS Cl - HCO 3 - 95-110mmol/L 24-29mmol/L 8 ECF Electrolytes

9. To calculate daily fluid and electrolyte requirements; must measure or estimate daily losses Body loses H 2 O through : Gain Through : Expired air i ) food Skin (perspiration) ii) drinks Urine iii) endogenous meta Faeces CHO, Prot, Fats Na+, K+, are lost in sweat, urine and faeces and replaced from ingested foods. 9 DAILY FLUID AND ELECTROLYTE REQUIREMENTS

10. WATER TROPICS ( mls ) TEMPERATE CLIMs( mls ) Losses Insensible 1,700 1,000 Urine 1,500 1,500 Faeces 200 200 TOTAL 3,400 2,700 Gain (endogenous production from metab of CHO, Prot and Fat 200mls 200mls Net H 2 O requirement 3,200mls 2,500mls 10 Daily fluid losses and gains

11. The surgical patient who requires IV Fluid therapy is not likely to pass stool in 24 hours, so will need 3L in 24hrs in the tropics and 2.3L in temperate climates For every 1 C rise in body temperature, daily fluid requirement rises by 12% to make up for fluid loss through increased sweating 11

12. SODIUM TROPICS( mmol ) TEMPERATE REGIONS( mmol ) Urine Sweat Faeces 114 10-16 10 80-110 - 10 Total 130-140 90-120 12 DAILY ELECTROLYTE LOSSES

13. Potassium Tropics Temperate regions Urine Sweat Faeces 50mmol Negligible 10mmol 60mmol - 10mmol Total 60mmol 70mmol 13

14. GI Secretion Volume Litres /Day Saliva Gastric juice Bile Pancreatic juice Intestinal secretions 1-1.5 2.5 0.5-1 1.0 3 Total 7-9 14 TOTAL DAILY VOLUME OF GI SECRETIONS

15. GI Secretions Na+ K+ Cl - HCO3 Gastric juice Bile Pancreatic Juice Small intestinal juice 60 140 140 110 9 4 5 5 100 100 75 100 - 28 80 30 15 TOTAL DAILY ELECTROLYTE CONTENTS GI SECRETIONS

16. Body store of glycogen=400grams Provides about 1,600Kcal (6694Joules) of NRG Used up on first day of starvation After wards 70-90% of NRG demand is met by; combustion of FAT, and PROTEIN 100-150g of exogenous glucose i.e. 1674-2508 Joules if given; reduces gluconeogenesis to minimum and prevents acidosis Give the surgical patient 2L, 5% dextrose/day=100g glucose for daily energy 16 ENERGY REQUIREMENTS

17. Vitamins Vit C: essential for normal wound healing (100-200mg/day Vit B complex: essential for CHO metabolism Prolonged I.V Fluid therapy requires: Multivitamins Trace elements Minerals ( Mg 2 +, , Zn 2 +, Chromium) 17

18. 18 SUMMARY OF DAILY REQUIREMENTS Requirements Tropics Temperate Water Na+ K+ Carbohydrate 3L 130mmol 50mmol 100g 2.5L 80-100mmol 60mmol 100g Provided by: 1L R/lactate (Na 131, K 5, Ca 2,Cl 111, NaHCo3- 29 mmol /L respectively 2L 5%Dextrose (100g glucose) 3g KCl and Vit C and B-complex 1/2L N/saline 2L 5% dexrose 3g KCl and Vit C and B-complex

19. I.V fluid therapy is needed to correct: Dehydration Shock Electrolyte imbalance And acid base disturbances 19

20. IV Fluid Human Plasma 0.9% Saline 4% dextrose 0.18% saline Ringers lactate 5% Albumin 4% Gelatine Osmolality Na+ Cl - K+ Ca2+ Mg2+ Lactate HCO3- 291 135-145 95-110 3.5-5.0 2.2-2.6 0.8-1.0 1.0-2.0 23-27 308 154 154 - - - - 283 30 - - - - - 278 131 111 4 2 - 29 - 300 150 - - - - - 290 145 - - - - - 20 Electrolyte content of some IV Fluids ( mmol /L)

21. NB normal daily losses(urine, faeces , insensible loss) 3L fluid/day + Na + 130mmol, K + 60mmol added as 20mmol/L in each IVF bag, with monitoring of urine output and ECG Avoid excess amts of hypotonic crystalloid, may lead to hyponatraemia esp children and elderly Adjustments based on regular clinical examination, measurement of losses, daily weighing, regular blood sample for electrolytes 21 Replacement of normal losses

22. Dehydration Hyponatraemia Hypernatraemia Hypokalaemia Hyperkalaemia Hypocalcaemia Hypercalcaemia Magnesium derangements 22 FLUID AND ELECTROLYTE PROBLEMS

23. Strictly, loss of water Loss of water and electrolytes esp. Na+ and other electrolytes Loss of ECF may be ICF as well Rapid in acute dehydration e.g. ints obstr Slow in GOO (chronic dehydration) where ECF and ICF with large amts of K+ loss A 60kg W/ Afr losses 2.5L to show signs of dehydration 4% of bdy wt. loss of fluid = moderate dehydration 23 DEHYDRATION

24. Vomiting NG tube aspiration Diarrhoea Internal fluid shift e.g. interstitial fluid accumulation in injured tissue “Third space” losses (burns, peritonitis, infectious oedema , trauma, intestinal obstruction) Enterocutaneous fistula Polyuria 24 Causes of dehydration

25. From a good Hx (duration of symptoms) Dry inelastic skin with loss of turgor Dry mouth and mucosae Sunken eyes Collapsed peripheral Vns Tachycardia Scanty and concentrated urine Loss of gastric juice (metabolic alkalosis) Doarrhoea loss of HCO 3 - (metabolic acidosis) Continual fluid loss up to 3.5L, hypotension, tachycardia, sweating, fainting =shock 25 Clinical features of dehydration

26. PCV: raised, haemoconcentration , falls with hydration Hb : raised Serum urea: raised Initially no change in serum electrolytes, because loss is isotonic with plasma Latter, Na + , K + , Cl - levels fall HCO 3 - is low in metabolic acidosis and high in metabolic alkalosis 26 Investigations in dehydration

27. Urgency, may need R x without lab results Commence crystalloids after taking blood for electrolytes, urea, creatinine , PCV, Hb , ABGs IL Ringers/L (Na + 130, K + 4, Ca 2+ 4, Cl - 111 and HCO 3 - 27mmol/L. or N/S Na + 154mmol/L and Cl - 154mmol/L or Dextrose Saline Infuse fast (30-45mins) R/lactate best because of its electrolyte composition and it is isotonic with plasma , but not in GOO b/c it worsens alkalosis 27 Treatment of Dehydration

28. Monitor urine output: give another Litre in 1 Hour, continue aim for 30-50mls urine/hr NB subcutaneous VNs, Skin, Tongue, PR, BP, Mental state etc Add KCl 3g to infusion (20mmol ampoule/L) if urine output is good Reduce rate of infusion to 1L 8hrly (30d.p.m.) 2L 5% Dextrose, 1L R/L and 3g KCl added Vitamins B Complex and C daily. 28

29. Pass a urethral catheter NGT in GOO, subacute intestinal obstruction, others CVP line (catheter) normal=10-15mm of Water Hourly urine output (30-50mls/hr,), skin turgor , tongue, filling of sub/cut Vns , 1/2hrly Pulse, BP, frequent auscultation of the lung bases Monitor JVP avoid over hydration The most reliable monitor is the hourly urine output Create INPUT/OUTPUT chart 12 hourly check of serum U &Es 29 Monitoring IV Fluids in dehydration

30. Serum K+ <3.0mmol/L. can occur rapidly Normal range = 3.0-5.0mmol/L K+ important for cell excitability Excitability proportional to ratio of intra and extracellular concentrations Total body K+ about 3,150mmol (with 2% i.e. 50-60mmol in ECF Most important intracellular cation (140mmol/L) 30 HYPOKALAEMIA

31. GIT loss ( Diarrhoea , Vomiting, fistulae) K+ in diarrhoeal stool=20-40mmol/L In gastric juice=9mmol/L K+ depletion is considerable in GOO – ICF K+ diffuses to replenish ECF loss from vomited gastric juice K+ also lost in urine as a result of ↑ aldosterone secretion to conserve Na+ water in dehyadration 31 Causes of Hypokalaemia

32. Peritonitis: causes hypokalaemia = loss in peritoneal exudate and GI secretions within intestines: paralytic ileus Diuretic therapy (loop and thiazide diuretics) Diabetes mellitus Alkalosis 32

33. Muscle weakness, lethargy, slurred speech Paralytic ileus Cardiac arrhythmias Hyporeflexia Hypotension in post operative period may ppt cardiac arrest Constipation 33 Clinical features of hypokalaemia

34. Insure satisfactory and adequate urine output Give IV Fluids (saline or dextrose saline) 90-150mmol of K+ in 5% Dextrose is given at a rate not exceeding 20mmol/hour to prevent cardiac arrest ( Usu In diastole) Repeat until serum K+ corrects Monitor urine output and ECG In chronic dehydration (GOO) K+ loss is much and takes several days to correct 34 Treatment of Hypokalaemia

35. Calculate the deficit in mmols Weigh the patient Deficit in mmols x Weight of patient in Kgs x 0.6 = total potassium in mmols The above is added to daily ration of potassium = 1mmol/Kg/day (approx. 50 – 60mmols Add to IV N/saline at 20mmol ampoule 8 hourly 35

36. Never give K + as Bolus Monitor Hrly Urine output Monitor ECG Never give more than 20mmol/Hr in case of urgent correction Remember maintenance 36

37. Food: -citrus fruits, Tomato juice, coconut milk, milk, tea and meat soup Banana Plantain Have adequate K + intake orally Slow K tablets 37 Sources of K +

38. Depressed ST segment Flat or inverted T-Waves Prominent U- waves Prolonged QT interval Tachycardia and ectopic beats 38 ECG CHANGES

39. Serum K + over 6mmol/L CAUSES Renal failure Shock Severe metabolic acidosis (from exchange of intracellular K + with hydrogen ions Destruction of large number of cells e.g. massive injury, burns, massive blood transfusion of old stored blood Main danger cardiac arrest (ventricular fibrilation or asystoli ) 39 HYPERKALAEMIA

40. Find out underlying cause Always R X under ECG monitor Give IV NaCHO 3 - 80-100mmols to combat acidosis Glucose under the influence of insulin uses K + to form glycogen Give 10i.u of soluble insulin in 1L of 5% dextrose intravenously CaCl 2 averts cardiac arrest if arrhythmia occurs Give 10% Calcium Gluconate : 10ml maximum dose = 50mls Ion exchange resin, Resonium A or Kayexalate , 40-80mg/day orally or by enema exchanges Na + for K + Peritoneal dialysis: removes excess K + from serum 40 TREATMENT OF HYPERKALAEMIA

41. 1000mmol total body store (70kg man) 65% in bone Most reminder in ECF 35% of total in ICF in muscles Only 1% in ECF Cells of high metabolic act have ↑ est conc Serum level 0.75-0.9mmol/L about 1/3 bound to protein Essential for elaboration and activation of certain enzymes 41 Magnesium/ hypomagnesaemia

42. Activates alkaline Phosphatase Activates pyrophosphates and some peptides Some enzymes which transfer phosphates from ATP to ADP Daily requirements=12.5mmol 2/3 rd and 1/3 rd excreted in feces and urine respectively 42

43. Serum level < 0.5mmol/L Has to be thought of to be diagnosed Any Pt. on IV Infusion for more than 7 days (GI loss, NG tube aspiration, diarrhoea , fistulae with behavioral disturbances, depression or confusion: give prophylactic Mg 2+ 10mmol/L daily for 5-7 days 43 Hypomagnesaemia

44. Neuromuscular hyperactivity –coarse Irregular tremors Muscular twitches Abdominal cramps Hyper- reflexia Convulsions Ventricular arrhythmias Paralytic ileus Behavioral disturbances Irritability, disorientation, depression, delirium and confusion 44 Symptoms of hypomagnesaemia

45. Behavioral disturbances may predominate in hypomagnesaemia than hypocalcaemia Cardiac arrhythmias and fall in BP may occur Trousseau’s and Chvostek’s sign may be positive R X : MgSO 4 25% or 50% solution 1ml of 50% solution contains 2mmol Mg 2+ 0.25 mg is given daily till serum concentration becomes normal 45

46. Keep an input/output chart Assess patient for state of hydration Monitor serum electrolytes and blood urea 12 hourly Watch out for fluid over load Note electrolyte imbalance signs and symptoms of electrolyte imbalance, immediately investigate and correct 46 Observing patients on fluid and electrolyte therapy

47. Explain the need Set up in a forearm vein Long saphenous vein for cut-down Set up under aseptic conditions Always wear gloves Rate of infusion (D/Min) depend on amount to be delivered No. of drops/minute is approx No. of liters in 24hours multiplied by 10 E.g. 3L/day = 30 drops/Min. 1L 4hrly = 60 d.p.m Change Vn . Needle and drip set every 48hrs 47 Observing Patients on IVF infusion CTND

48. Thrombophlebitis Local sepsis Septicemia Fluid overload Air embolism Pyrogenic reaction 48 COMPLICATIONS OF IV FLUID THERAPY

49. The body produces large quantities of acid in metabolism, yet hydrogen ion concentration remains constant Normal pH= 7.38-7.42 Undue increase in [H+] concentration may lead to: Hypotension Impaired cardiac function Cardiac arrest and death 49 HYDROGEN ION REGULATION AND ACID BASE BALANCE

50. Undue decrease in [H+] concentration(alkalosis) may cause Neuromuscular incoordination and tetany Muscle cramps CNS disorders e.g. convulsions Regulation of hydrogen ion concentration is very important to the body 50

51. Life is possible at pH range 6.8-7.7 The metabolism of proteins, CHO and fats generates 50-100mmols of acid daily, mostly phosphoric acid and sulphuric acids Same metabolism produce 15,000mmols of carbondioxide daily Yet the body maintains a pH of 7.40 this is possible by (respiratory, renal and liver, buffer mechanisms) 51 Regulation of pH in the body

52. Renal, pulmonary, or hepatic impairment can lead to acid-base disturbances RESPIRATORY ACIDOSIS Rise in arterial CO 2 from alveolar hypoventilation Can occur acutely after respiratory depression From respiratory muscle weakness Chest injury Acute airway obstruction pa CO 2 may be permanently elevated in chronic obstructive airway disease 52 CLASSIFICATION OF ACID BASE DISTURBANCES

53. Respiratory acidosis in the perioperative period could be due to: Atelectasis Respiratory infection Retained sputum Abdominal distension and splinting of the diaphragm Wound pain High doses of opaite analgesics 53

54. Result of hyperventilation causing low CO 2 Iatrogenic from deliberate or mistakenly overenthusiastic artificial ventilation Could be secondary to anxiety or distress Can cause paraesthesia , tetany and chest pain 54 Respiratory Alkalosis

55. Characterized by low bicarbonate with compensatory fall in CO 2 from hyperventilation Complaint: Shortness of breath and hyperventilation with deep sighing respiration ( Kussmaul’s respiration) May be caused by excess production of acid as in: Lactic acidosis from tissue hypoxia Renal and liver failure Excess loss of HCO 3 - from pancreatic or intestinal fistulae Diarrhoea or purgative abuse 55 Metabolic acidosis

56. Treat underlying cause Give NaHCO3 orally or IV In metabolic acidosis, K + leaves the cell, when acidosis is corrected, and by giving bicarbonate, K + goes back to the cell causing hypokalaemia 56 Treatment of metabolic acidosis

57. Characterized by pH greater than 7.4 and an elevated bicarbonate Often accompanied by hypokalaemia from excretion of Na + and K + in exchange for H + ions in the distal convoluted tubules This creates a vicious cycle of hypokalaemic alkalosis in which urine is paradoxically becomes acidic as the kidney tries to retain K + and Na + in preference to H + ions The most common cause of alkalosis in surgical patients is loss of gastric acid from vomiting e.g. GOO) or NG Tube aspiration 57 Metabolic alkalosis

58. ABG (arterial blood gases) analysis Measurement of venous HCO 3 - and Cl - Serum Creatinine, Urea and Electrolytes If [ Cl - ] + [HCO 3 - ] + 8 < serum [Na + ] Conc This implies an abnormally high “anion gap” exists, indicating metabolic acidosis Treat underlying cause, alkali therapy to raise pH to greater than 7.2 58 Clinical Evaluation of Acid-Base Disturbances