Auer Ch 3 Fluids, Lytes, Acid-Base

Front 1

Components of extracellular fluid:

Back 1

interstitial fluid, plasma, lymph, transcellular fluid (synovial, pleural, abdominal, CSF)

Front 2

Volume of gastrointestinal secretion:

Back 2

100L every 24 hours (roughly equivalent to the ECF volume) for 500kg horse

Front 3

% of body weight represented by total body water (ICF + ECF):

Back 3

TBW is 60% of BW in adults 80% of BW in neonates

Front 4

What % of TBW/ BW is ECF?

Back 4

ECF is 1/3 of TBW and 20% of BW in adults, ECF is ½ of TBW and 40% of BW in neonates

Front 5

What % of TBW/ BW is ICF?

Back 5

ICF is 2/3 of TBW or 40% of BW in adults

Front 6

What factor is used for calculation purposed for substances that distribute across the ECF?

Back 6

0.3 for adults, 0.4 for young animals

Front 7

What % of BW is BV?

Back 7

8% in sedentary horses, can be up to 14% in fit horses, 15% in neonates

Front 8

What are the main anions and cations in plasma?

Back 8

Cation- Na, Anions- Cl, HCO3

Front 9

Role of protein in plasma:

Back 9

act as an anion, provide oncotic pressure

Front 10

Main contributors to oncotic pressure:

Back 10

albumin and particles of similar size

Front 11

What % of the ECF is interstitial fluid?

Back 11

75%

Front 12

Main solutes of interstitial fluid:

Back 12

Na, HCO3, Cl

Front 13

Main anions, cations in intracellular fluid:

Back 13

cations- K, Mg, anions- PO4, proteins

Front 14

Define osmolality:

Back 14

concentration of osmotically active particles in solution per kg of solvent

Front 15

Define osmolarity:

Back 15

number of particles of solute per liter of solvent

Front 16

Normal plasma osmolality:

Back 16

275-312 mOsm/kg

Front 17

Define tonicity:

Back 17

osmotic pressure generated by the difference in osmolality between 2 compartments

Front 18

Define colloid oncotic pressure:

Back 18

osmotic pressure generated by proteins (mainly albumin)

Front 19

Normal COP ranges:

Back 19

15-22.6 mmHg (foals), 19.2-31.3 mmHg (adult)

Front 20

Where does interstitial and vascular solute and water exchange occur? Time frame?

Back 20

Occurs in capillaries rapidly (30-60 min)

Front 21

What controls exchange or filtration between the vascular and interstitial space?

Back 21

Balance of forces favoring filtration vs forces retaining fluid in the vascular space (starling’s law)

Front 22

What are the forces that favor filtration (movement of solutes/ water out of the vascular space)?

Back 22

Capillary hydrostatic pressure, tissue oncotic pressure

Front 23

What are the forces that favor retention of water/ solutes within the vascular space?

Back 23

Plasma oncotic pressure, tissue hydrostatic pressue

Front 24

What controls exchange between the interstitial space and the intracellular space? Time frame?

Back 24

# of osmotically active particles in each space, slow process taking up to 24 hrs

Front 25

What are the significant contributors to ECF osmolality?

Back 25

Na, glucose, urea but urea is permeable to cell membranes so is not involved in effective osmolality

Front 26

Define osmolar gap:

Back 26

difference between measured osmolarity and calculated osmolarity

Front 27

Define buffer:

Back 27

compound that can accept or donate protons to maintain the pH within a narrow range

Front 28

What are the primary buffers in the different fluid spaces?

Back 28

HCO3 in ECF, proteins & phosphates ICF

Front 29

What is the HCO3 equation?

Back 29

H + HCO → H2CO3 → CO2 + H20

Front 30

Define acidosis:

Back 30

processes that cause net accumulation of acid

Front 31

Define alkalosis:

Back 31

processes that cause net accumulation of alkali

Front 32

Define acidemia:

Back 32

pH lower than normal in the ECF

Front 33

Define alkalemia:

Back 33

pH higher than normal in the ECF

Front 34

What creates acidemia?

Back 34

Decreased pH, increased CO2, decreased HCO3

Front 35

What creates alkalemia?

Back 35

Increased pH, decreased CO2, increased HCO3

Front 36

define metabolic acidosis/ expected response:

Back 36

decreased HCO3 due to loss or buffering, decrease PCO2 by increasing ventilation

Front 37

examples of when metabolic acidosis occurs:

Back 37

accumulation of lactic acid, HCO3 loss from diarrhea

Front 38

define metabolic alkalosis/ expected response:

Back 38

increased HCO3, increase PCO2 (decrease ventilation)

Front 39

examples of when metabolic alkalosis occurs:

Back 39

loss of Cl ions

Front 40

define respiratory acidosis/ expected response:

Back 40

increase PCO2 due to alveolar hypoventilation, increase HCO3 with increased renal retention

Front 41

define respiratory alkalosis/ expected response:

Back 41

decreased PCO2 due to alveolar hyperventilation/ decrease HCO3 by increasing renal secretion

Front 42

response and time frame of response to primary metabolic disorders:

Back 42

respiratory response that begins immediately and complete within hours

Front 43

response and time frame of response to primary respiratory disorders:

Back 43

titration of non HCO3 buffers to change plasma HCO3 concentration (immediate) kidney modifies HCO3 secretion or retention which begins within hours but takes 2-5 days to respond

Front 44

define mixed acid-base disorder:

Back 44

2 separate primary disorders are present

Front 45

when is a mixed disorder suspected?

Back 45

Adaptive response is lower or higher than the expected response

Front 46

what are the expected compensations for metabolic conditions?

Back 46

Respiratory conpensation should be a 1mmHg change in PCO2 for every 1 mEq/L change in HCO3

Front 47

what are the expected compensations for respiratory conditions?

Back 47

HCO3 should change 1mEq/L (acute resp acid), 2-3 (acute resp alk), 3-4 (chronic resp acid), 5-6 (chronic resp alk) for each 10mmHg change in PCO2

Front 48

what are the measured and calculated values on blood gas analysis?

Back 48

pH, PCO2, PO2 (measured) tCO2, HCO3, BE (calculated)

Front 49

define hypercapnia:

Back 49

increased PCO2 also termed hypercarbia reflects hypoventilation

Front 50

define hypocapnia:

Back 50

decreased PCO2 also termed hypocarbia reflects hyperventilation

Front 51

define tCO2:

Back 51

calculation of both dissolved CO2 and HCO3 in sample

Front 52

define base excess:

Back 52

amount of strong acid or base required to titrate iL of blood at pH 7.4 with PCO2 constant at 40mmHg

Front 53

what are the steps to interpret acid-base?

Back 53

1) check pH, determine if acidotic or alkalotic 2) check PCO2, determines respiratory component, if too high then acidosis, if too low, alkalosis 3) check HCO3, determines metabolic component, if high then alkalosis, if low then acidosis 4) determine if compensation is what is expected

Front 54

normal PaO2:

Back 54

5x FIO2 (80-100mmHg)

Front 55

define hypoxemia:

Back 55

decreased PaO2

Front 56

causes of hypoxemia:

Back 56

decreased FIO2, hypoventilation, ventilation/perfusion mismatch, shunt, diffusion impairment

Front 57

normal PvO2:

Back 57

40mmHg

Front 58

define anion gap:

Back 58

difference between sum of common cations and sum of common anions AG=Na + K – Cl + HCO3

Front 59

what does the anion gap represent?

Back 59

Estimation of unmeasured anions

Front 60

normal anion gap:

Back 60

10-11 mEq/L

Front 61

what are the flaws of Henderson-hasselbach in acid-base evaluation?

Back 61

Does not account for other electrolytes, weak acids, or plasma proteins

Front 62

principals of stewart’s acid-base:

Back 62

maintenance of electroneutrality, satisfaction of dissociation, conservation of mass

Front 63

what are the independent valiables in stewarts approach?

Back 63

Those that can be externally altered: strong anion difference, PCO2, and total concentration of weak acids

Front 64

what is the SID?

Back 64

Difference between the concentrations of strong cations and the concentration of strong anions

Front 65

stewarts primary cation:

Back 65

Na

Front 66

stewarts primary anion:

Back 66

Cl, other unmeasured anions

Front 67

what does an increase in SID indicate?

Back 67

Indirectly indicated increased unmeasured anions

Front 68

what is the primary disturbance in stewarts approach?

Back 68

Change in 1 or more of the independant variables (SID, PCO2, weak acids)

Front 69

what is the difference between maintenance and replacement fluids?

Back 69

Replacement fluids are given to replace lost fluids and electrolyte composition is similar plasma but maintenance fluids have less Na and lore Ca, K, Mg than replacement fluids

Front 70

examples of maintenance fluids:

Back 70

oral fluids with oral electrolyte formulations added, 0.45% saline with K, Mg, Ca addess

Front 71

daily fluid requirements per day:

Back 71

60 ml/kg/day

Front 72

define dehydration:

Back 72

loss of total body water

Front 73

define hypovolemia:

Back 73

form of dehydration due to loss of circulating volume

Front 74

equation to correct hypovolemia:

Back 74

correction = estimated loss (%) x BW

Front 75

example of HCO3 precursors in BES:

Back 75

lactate or acetate with gluconate

Front 76

where are HCO3 precursors metabolized?

Back 76

Lactate- liver, acetate- body tissues

Front 77

what situations is saline used as replacement fluids?

Back 77

When Na is lower than 125 mEq/L, in diseases with high K

Front 78

what occurs with long term BES use as the sole IVF therapy?

Back 78

Hypernatremia, hypokalemia, hypomagnesemia, hypocalcemia

Front 79

what is the rate for Ca supplementation?

Back 79

50-100mL Ca gluconate in 5L to maintain normocalcemia or 500mL in 5L to correct hypocalcemia

Front 80

maintenance requirement of Mg:

Back 80

13 mg/kg/day (elemental), 31 mg/kg/day (MgO), 64 mg/kg/day MgCO3, 93 mg/kg/day MgSO4

Front 81

what is the maximum rate for K supplementation?

Back 81

0.5 mEq/kg/hr

Front 82

rules for HCO3 supplementation:

Back 82

horse should have normal respiratory function, pH < 7.2, give ½ calculated amount rapidly, rest over 12-24 hrs, don’t give with Ca containing solutions

Front 83

equation for HCO3 requirements:

Back 83

BE (mEq/L) x BW (kg) x 0.3 or normal tCO2-actual tCO2 x BW x 0.3

Front 84

when is oral HCO3 supplemented?

Back 84

When the loss is ongoing (diarrhea)

Front 85

recipe for IV HCO3 supplementation:

Back 85

5% solution contains 0.59 mEq/L, 8.4% solution contains 1 mEq/L. for 5% 1part HCO3 to 3 parts water. for 8.4% 150mL added to 850mL sterile water

Front 86

recipe for oral HCO3 supplementation:

Back 86

1 gm NaHCO3 = 12 mEq HCO3

Front 87

when is dextrose administered?

Back 87

Hypertonic dehydration, hyperlipemia, pregnant mares

Front 88

what is the rate of 5% dextrose administration?

Back 88

1-2 mg/kg/min

Front 89

when are colloids administered?

Back 89

When TP < 4 g/dL, albumin < 2 g/dL, or COP < 12 mmHg

Front 90

what is the equation for plasma administration?

Back 90

Plasma (L) = (TP desired – TP patient) x 0.05 BW / TP donor

Front 91

what is the dose of HES?

Back 91

10 mL/kg/day

Front 92

what are complications of higher doses of HES?

Back 92

With 20mL/kg doses increased coagulation times because of decreased vWF antigen and factor 8

Front 93

what type of container should be used for blood collection?

Back 93

Plastic to preserve platelet function

Front 94

which anti-coagulent is used for short term storage (<24 hrs)?

Back 94

Na citrate

Front 95

which anti-coagulent is used for long term storage (< 10 days)?

Back 95

Acid citrate dextrose

Front 96

which anti-coagulent is used for prolonged storage (> 10 days)?

Back 96

Citrate phosphate dextrose + adenine

Front 97

what issues occur with acid citrate dextrose that prevent its used for prolonged storage?

Back 97

Decreases concentration of 2,3 diphosphoglycerate which causes decreased oxygen release to tissues

Front 98

equation for whole blood transfusion:

Back 98

liters blood = (PCVdesired-PCVactual) x 0.08BW / PCV donor

Front 99

dose of whole blood in acute situations:

Back 99

10-20ml/kg

Front 100

define oxyglobin:

Back 100

glutaraldehyde polymierized bovine Hb solution

Front 101

benefits of oxyglobin:

Back 101

restore oxygen carrying capacity, volume explansion for colloid action

Front 102

dose of oxglobin:

Back 102

15mL/kg given at rate of 10ml/kg/hr

Front 103

shock dose and time frame for administration of fluids:

Back 103

60-90 mL/kg in 1st hour

Front 104

benefits of enteral fluids:

Back 104

administration of fluid directly to gi tract, stimulation of gastrocolic reflex, decreased expense, decreased need for precise fluid composition

Front 105

recipe for enteral fluid electrolyte composition:

Back 105

5.27g NaCl + 0.37 g KCl + 3.78 g NaHCO3 per liter water giving 135 mEq/L Na, 95 mEq/L Cl, 5 mEq/L K, 45 mEq/L HCO3

Front 106

what is the rate of administration of continuous enteral fluids?

Back 106

4-10L/hr

Front 107

how much does blood volume expand with 1L HS?

Back 107

4.5L

Front 108

what is the estimated duration of effect of HS?

Back 108

~45 min

Front 109

what is the dose of HS?

Back 109

4mg/kg

Front 110

volume expansion for HES?

Back 110

1L for each 1L of hetastarch (2 total)

Front 111

dose of HES:

Back 111

10mL/kg

Front 112

duration of activity of HES:

Back 112

120 hours

Front 113

what is affects rate of iv fluid flow?

Back 113

Flow is proportional to the diameter of the catheter and inversely proportional to the length of the catheter and the fluid viscosity

Front 114

electrolyte composition of plasma:

Back 114

Na 132-146, K 2.8-5.1, Ca 9-13, Mg 1.8-3, Cl 99-110, buffer source tCO2 20-26, osmolality 285

Front 115

Electrolyte composition of LRS:

Back 115

Na 130, K 4, Ca 3, Mg 0, Cl 109, buffer source lactate 28, osmolality 274

Front 116

Electrolyte composition of Norm R:

Back 116

Na140, K5, Ca0, Mg3, Cl98, buffer source acetate, gluconate 50, osmolality 295

Front 117

Electrolyte composition of 0.9% saline:

Back 117

Na154, K0, Ca0, Mg0, Cl154, no buffer source, osmolality 308

Front 118

Electrolyte composition of 5% dextrose:

Back 118

Na, K, Ca, Mg, Cl all 0, no buffer source, osmolality 253

Front 119

Electrolyte composition of 2.5% dextrose in 0.45% saline:

Back 119

Na 77, K0, Ca0, Mg0, Cl77, no buffer source, osmolality 280

Front 120

Electrolyte composition of 1.25% NaHCO3:

Back 120

Na143, K0, Ca0, Mg0, Cl0, buffer source HC03 149, osmolality 298

Front 121

Difference between LRS & Norm R:

Back 121

LRS has 3 Ca and no Mg, Norm R has 0 Ca and 3 Mg

Front 122

Catheter materials:

Back 122

polypropylene= polyethylene, Teflon, polyurethane, silastic in order from most to least thrombogenic