You are here. Milky Way Galaxy

Transcription

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3 You are here Milky Way Galaxy

4 اللهم انفعنا بما علمتنا وعلمنا ماينفعنا وزدنا علما

5 Blood volume, pressure, osmolality, and ph

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7 The kidney plays a fundamental role in Homeostasis

8 Fluid balance is one of the most important subjects in medicine.

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10 This process keep the level of salts and other substances in the body at a constant. Water Electrolytes Acid-Base Body Fluids Homeostasis

11 I Anatomy Physiology

12 II RSL

13 III Disorders Fluid Therapy

14 Anatomy Physiology

15 RULE OF THIRDS

16 1/3 Free 1/3 Fluid 1/3 Food

17 روى الترمذي في صحيحه ع ن الم ق د ام ب ن م ع د ي ك ر ب ق ا ل: س م ع ت ر س ول ه للا ص لهى ه للا ع ل ي ه و س لهم ي ق ول : م ا م أل آد م ي و ع اء ش ر ا م ن ب ط ن ب ح س ب اب ن آد م أ ك الت ي ق م ن ص ل ب ه ف إ ن ك ان ال م ح ال ة ف ث ل ث ل ط ع ام ه و ث ل ث ل ش ر اب ه و ث ل ث ل ن ف س ه

18 2/3 water

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20 Body Fluids Compartments Intracellular [2/3] Extracellular [1/3] 1. Intravascular 2. Interstitial 3. Transcellular: ( CSF, synovial, pericardial & pleural )

21 Body Weight Total Body Water (60-75%) (2/3) ICF (1/3) ECF 1/5 IVF 4/5 ISF

22 Fluid compartments ICF IVF capillary endothelium ISF cell membrane Although these compartments are classed as separate areas, water & electrolytes continually circulate between them.

23 WATER

24 WATER

25 Na WATER

26 Water will follow an osmotic gradient using aquaporins 1,2,3 Water follows salt

27 Fluid shifts Dictated partly by the size of the compartment, but mainly by tonicity. Intracellular Water balance is adjusted to maintain osmolality at a constant. Interstitial IV Extracellular fluid

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30 Isotonic Hypertonic cells shrink (crenate) Hypotonic cells swell and burst (lysis)

31 Anatomy Physiology BP RBF Osmoregulation Hormonal control Dilute urine Conc. Urine

32 Highest blood flow rate of any organ.

33 Renal regulation of BP

34 Renal Autoregulation keeping RBF constant over a range of arterial pressures. Intefered with by ACE inhibitors and decreases with age.

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36 Maintain osmolality constant in the body compartments.

37 Urine 50% 60% IWL 50% 35% 5%

38 In the absence of disease, should intake & output be equal? or should urine output always equal half of what is taken in? The half rule applies when the child has only maintenance needs and the amount of fluid being provided matches those needs.

39 In the absence of disease, should intake & output be equal? or should urine output always equal half of what is taken in? During evaluation of In & Out fluid charts The half-half rule applies only to maintenance needs after exclusion of recorded fluids used to repair the deficit & ongoing loses.

40 Relationship of Intake and Urine Output in a NORMAL 10-kg Child Receiving Various Volumes of Fluid* Diluted Conc. Urine

41 Water Conservation. ADH An acceptable osmolality range of mmol/l correspond to a daily urine output of 2-3 ml/kg/hr. Urine conc. from 50 to 1400 mosm.

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43 A D H

44 Water balance 1.A???? 3A ADH 1.Dietary RSL. Protein Solutes Aldosterone Angiotensin II 2.H2O intake. Conserve water A ANP Water loss

45 IV fluids Kidneys can only Conserve or lose water not replacing it Anuria

46 Kidneys can only Conserve or lose water not replacing it

47 Formation of dilute urine Formation of conc.urine Filtrate is normally dilute All what kidneys have to do is to let it go

48 Formation of conc.urine GFR Decreased GFR will decrease the amount of NaCl delivered to the distal tubules, lower medullary hypertonicity, and impair renal concentrating ability. Counter current Absorption of Na without water Urea ADH Absorption of urea in the collecting tubules, influenced by ADH, enhances the concentration gradient in the medullary interstitium.

49 Bulk of body needs Counter Current Multiplier Fine Tuning

50 Water Conservation Loop of Henle Establishes conditions necessary to conce. urine. Creates osmotic gradient. Deep in medulla, not for its own benefit, But to the collecting duct adjacent to it. If Loop is disabled, then collecting duct cannot give concentrated urine.

51 loop of Henle vasa recta 300 mosm Osmotic gradient

52 50% R % filtered load level relative to plasma 60% S 60% R Urea Recycling

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54 Normal Daily Fluctuations Water Loss Water Gain < 1% Daily fluid intake should be balanced by fluid loss Total fluid volume fluctuates by less than 1% of body weight

55 Dehydration Water Loss Water Gain > 1% Dehydration is defined as a 1% or greater loss of body mass as a result of fluid loss

56 Friends

57 Sensors 1. Osmoreceptors signal osmolality, 2. Baroreceptors signal volume change. Osmoreceptors are more sensitive in inducing ADH secretion.

58 OSMOREGULATION

59 OSMOREGULATION

60 Water intake ADH set point normally at 280 mosm.

61 Baroreceptors Osmoreceptors Gain of excess salt Loss of fluids

62 Water Deficit The body senses fluid osmolality and volume, with the aim of maintaining BP osmolality mosm/l. Plasma Osmolality Osmoreceptors Atrial Pressure Thirst Water Absorption Vasopressin Reduce Urine

63 Baroreceptors Water Excess Atrial Pressure Plasma Osmolality. Atrial natriuretic peptide Increase Na excretion & Fluid loss. inhibiting 1. Na channels. 2. Renin and aldosterone. ANP Increased Urine Water resorption

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65 RSL Definition Constituents Importance Infant s limitations Red flags illness

66 The renal solute load exerts a major effect on

67 DEFINITION Renal solute load refers to all solutes of endogenous or dietary origin that require excretion by the kidneys.

68 Renal solute load 1. Electrolytes that are consumed in amounts that exceed body needs 2. Nitrogenous end products resulting from protein metabolism.

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70 Renal solute load Diets that are high in electrolytes and/or protein will increase the amount of fluid required.

71 Neonates & young Infants Can not indicate thirst Can not reach free water when needed Low urine concentrating capacity 600 mosmol/kg in preterm. 800 mosmol/kg in term. 900 mosmol/kg in infants.

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74 RSL during illness Becomes an important consideration Water losses are increased because of: 1. Fever. 2. Diarrhea. 3. Diminished intake. several of these circumstances are likely to occur at the same time.

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76 Disorders Fluid Therapy

77 Disorders of body fluids are among the most commonly encountered problems in the practice of clinical medicine.

78 Polyuria Hypovolemia CP Neontes Dehydration Hypernatremia Hypervolemia

79 Hyponatremia Hypernatremia OSMOREGULATION

80 ECF volume contraction ISF Dehydration Hypotonic electrolytes IVF Hypovolemia Isotonic electrolytes ½ N-D5 Ringer s lactate Normal saline

81 Dehydration Hypovolemia SHOCK

82 Percent Dehydration Infant Child Mild 5% 3% Moderate 10% 6% Clinical Signs and Symptoms Increased thirst, tears present, mucous membranes moist, ext. jugular visible when supine, capillary refill > 2 seconds centrally, urine specific gravity > Tacky to dry mucous membranes, decreased tears, pulse rate may be elevated somewhat, fontanelle may be sunken, oliguria, capillary refill time between 2 and 4 seconds, decreased skin turgor Severe 15% 9% Shock >15% >10% Tears absent, mucous membranes dry, eyes sunken, tachycardia, slow capillary refill, poor skin turgor, cool extremities, orthostatic to shocky, apathy, somnolence Physiologic decompensation: insufficient perfusion to meet end-organ demand, poor oxygen delivery, decreased blood pressure.

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84 Assessing fluid balance» Clinical assessment: 1. Vital signs; HR,BP & RR 2. Capillary refill time 3. Skin elasticity 4. Body weight 5. Urine output» Review of fluid balance charts.» Review of blood chemistry.» Inferior vena caval diameter.» Bio Impedance Analysis (BIA).» CVP.

85 INFERIOR VENA CAVAL DIAMETER 8-11 mm/m2 BSA Overhydration > 11

86 Peritoneal Dialysis MACHINES FOR BIOIMPEDANCE ANALYSIS

87 Peritoneal Dialysis

88 Parenteral Fluid Therapy in Children

89 FLUID THERAPY RESUSCITATION DEFICIT MAINTENANCE Crystalloid Replace acute loss Hge, GI loss Renal Skin 3 rd space etc Colloid Blood 20mL/kg LR, 0.9%NS X2 10 ml/kg Blood, Plasma Fluid ELECTROLYTES FWD ONGOING LOSES Replace abnormal loss Fluid ELECTROLYTES NUTRITION?? 1. Replace normal loss (IWL + urine) 2. Nutrition support?? D5, 0.45% NS, meq/l K D5, 0.2 % NS, 20 meq/l K

90 Requirements Fever (add 12% for each degree) Restless Warm ambient temperature Hyperventilation

91 Requirements Hypothermia High humidity Oliguria/anuria Reduced consciousness Retention/edema Increased ICP

92 Approach to a Fluid & Electrolyte Problem

93 Holliday-Segar Formula for Determining Calories (and Fluid Volume) for Average Hospitalized Patient at Maintenance

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95 Should maintenance fluids be administered evenly each hour? Maintenance fluids do not need to be provided evenly when infused parenterally. Flexibility is encouraged

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97 Deficit: Fluid

98 Deficit: Fluid Acute weight change is the most direct basis for determining the amount of deficit fluid; A loss of body weight > 1% / day almost always must be fluid.

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100 Ongoing Losses

101 Ongoing Losses: Fluid These losses can be measured directly. Replace output ml/ml every 1-6 hr

102 Post-operative fluids NS during surgery & in recovery room; Then ½ NS. Use ⅔ of the calculated maintenance.

103 Whenever possible the enteral route should be used

104 Fluctations less than 1%

105 1% diuresis

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107 Types of IV Fluids

108 Intravenous Solutions Crystalloids Balanced salt solutions 1. Isotonic 2. Hypertonic 3. Hypotonic Colloid Solutions Solutions containing large molecular weight substances. 1. Proteins (Albumin) 2. Non-proteins (Dextran)

109 Electrolyte solutions Plasma Isotonic solutions Hypotonic solutions Normal saline Ringer s lactate

110 Isotonic infusion Ringer s lactate Normal saline increases ECF ICF ISF Plasma Replace acute/ abnormal loss Children 750 ml 250 ml

111 Hypotonic infusion increases ICF > ECF Replace Normal loss (IWL + urine) ICF ISF Plasma 660 ml 255 ml 85 ml

112 IVF ISF ICF

113 A normal plasma osmolality is mosm/kg. Infusing an intravenous solution peripherally with a much lower osmolality can cause water to move into red blood cells, causing hemolysis.

114 A normal plasma osmolality is mosm/kg. Thus, IV fluids are designed to have an osmolality that is either close to 285 or greater, Moderately higher osmolality fluids do not cause problems.

115 Peritoneal Dialysis اللهم انفعنا بما علمتنا, وعلمنا ماينفعنا, وزدنا علما You have now completed all secrets of Fluid Therapy!!!

116 MCQ 1 A 70 kg adolescent with vomiting and diarrhea for 4 days secondary to a viral infection. What hourly urine measurement would indicate that efforts to rehydrate this client have not yet been successful and should continue? ml per hour ml per hour ml per hour ml per hour

117 MCQ 2 16-year-old girl receiving IV fluids after surgery. Which of the following would suggest fluid volume overload? 1. Temperature 38.3 C, BP 96/60, pulse 96 and thready. 2. Cool skin, respiratory crackles, pulse 98 and bounding. 3. Complaints of a headache, abdominal pain, and lethargy. 4. Urinary output 700 cc/24 h, CVP of 5, and nystagmus.

118 MCQ 3 You are performing discharge teaching for a child with Addison s disease. It is MOST important to instruct the parents about 1. Signs and symptoms of infection. 2. Fluid balance. 3. Electrolyte balance. 4. Steroid replacement.

119 MCQ 4 A 3 year old child is receiving (TPN). To determine the patient s tolerance of this treatment, you should assess? 1. A significant increase in pulse rate. 2. A decrease in diastolic blood pressure. 3. Temperature in excess of (37 C). 4. Urine output of at least 30 cc per hour.

120 MCQ 5 The single best indicator of fluid status is: 1. Skin turgor 2. Intake and output 3. Serum electrolyte levels 4. Daily body weight.

121 MCQ 6 Which food will have the greatest impact on the water balance of the person consuming it? 1. A pickle 2. A banana 3. A milkshake 4. A happy meal