Fluids,Electrolytes, and Acid-Base Flashcards
(120 cards)
1
Q
In a textbook male, water represents what % or total body weight?
A
60%
OR 42 LITERS!!
2
Q
Total body water can be divided into what two compartments?
A
Intracellular ~ 40%
Extracellular ~ 20%
3
Q
What are the major ions of INTRAcellular volume?
A
“PMP”
“When you in the cell, you a PiMP”
Potassium
Mg
Phosphate
4
Q
What are the major ions of EXTRAcellular volume?
A
“Salt, milk, and a hamburger shift”
Na
Ca
Cl- AND HCO3
5
Q
How is extracellular fluid divided?
A
15 and 5 baby!
15% of total body weight = interstitial fluid
5% of total body weight = plasma
6
Q
What does capillary hydrostatic pressure do?
A
Pushes fluid OUT of the capillary
7
Q
What does interstitial oncotic pressure do?
A
Pulls fluid OUT of the capillary
8
Q
What does interstitial hydrostatic pressure do?
A
Pushes fluid INTO capillary
9
Q
What does capillary oncotic pressure do?
A
Pulls fluid into capillary
10
Q
What is the equation for net filtration pressure?
A
(Capillary hydrostatic - interstitial hydrostatic) - (capillary oncotic - interstitial oncotic)
11
Q
What is the glycocalyx?
A
Endothelial protective layer of the interior wall of a blood vessel. Acts as a “gate keeper”
***also has some anticoagulant properties
12
Q
What happens when the glycocalyx is distrusted?
A
Capillary leak ~ reduces tissue oxygenation
13
Q
What conditions impair the glycocalyx?
A
Sepsis
Ischemia
DM
Major vascular surgery
14
Q
What is the hematocrit?
A
It is the fraction of blood volume that is occupied by erythrocytes
15
Q
What is HCT increased by?
A
Increased number of RBCs (polycythemia) or decreased plasma volume (hypovolemia)
16
Q
What is Hct decreased by?
A
Decreased number of RBCs (anemia) or an increased plasma volume (hemodilution)
17
Q
What is osmoLALITY?!
A
Number of osmoles per kilogram of solution
“With a KILO of moles, you’re going to get LIT”
18
Q
What is osmoLARITY?
A
Numbers of osmoles per liter of solution
“LAREN loves to drink LITERS of fluid”
19
Q
What is osmosis?
A
Net mov of water across a semipermeable membrane (ONLY water)
20
Q
What is diffusion?
A
It’s the net movement of a substance from an area of higher concentration to an area of lower concentration across a FULLY permeable membrane
21
Q
What is osmotic pressure?
A
It’s the pressure of a solution against a semipermeable membrane that prevents water from diffusing that membrane
***function of the number of osmotically active particles in a solution
22
Q
What is an osmole?
A
It is the number of osmotically active particles in a solution
23
Q
How do you calculate plasma osmolarity?
A
(Na x 2) + (glucose/18) + (BUN/2.8)
24
Q
What is a normal osmolarity?
A
280-290 mOsm/L
25
What is the MOST important factor in osmolarity?!?!
Sodium!
26
What do hypotonic fluids do?
Water enters and CELL SWELLS
Ex: NaCl 0.45%
D5W
27
What do isotonic fluids do?
No water transfer and cell remains same size
Ex: NaCl 0.9%, LR, Plasmalyte
IN ADDITION: albumin, voluven, hespan
28
What do hypertonic fluids do to the cell?
Water exits and cell shrinks
Ex: NaCl 3%, D5 NaCl 0.9%, D5 NaCl 0.45%, and D5 LR
IN ADDITION: Dextran 10%
29
How long do crystalloids remain in the intravascular space?
30 mins!
30
Why is LR a better choice for large volume resuscitation?
Because large amounts of NaCl can cause hyperchloremic metabolic acidosis
31
Which two solutions can be used to dilute RBCs?
Plasmalyte and normal saline
32
How long do colloids increase plasma volume?
3-6 hours
33
Which colloids reduces blood viscosity and improves micro circulatory flow in vascular surgery?
Dextran 40
34
What electrolyte abnormality can albumin cause?
Hypocalcemia
Binds to calcium
35
What are some traits about dextran, hetastarch and hextend?
Coagulopathy ~ dextran > hetastarch > hextend
Don’t exceed 20 mL/kg!!!
36
Which colloid has the highest anaphylactic potential?
Dextran
37
Which is the ONLY colloid derived from human blood products?
Albumin!
38
What is the black box warning in synthetic colloids?
Risk of renal injury
39
What is normal potassium?
3.5-5.5
40
What is the most abundant intracellular cation?
Potassium
41
Which “kalemia” hyperpolarizes the cell?
Hypokalemia!
42
Which type of “kalemia” depolarizes membranes?
Hyperkalemia!!
43
What are some EKG findings for hypokalemia <3.5?!
U wave
Flattened t wave
QT interval prolongation
PR interval prolongation
44
What are some EKG findings for Hyperkalemia >5.5?
5.5-6.5 ~ peaked T waves
6.5 -7.5 ~ p wave flattening, PR prolongation
7.5-8.5: QRS prolongation
> 8.5 sine wave ~ vfib
45
What are some things that redistribute K inward?
Insulin + D50
Bicarb
Hyperventilation
Beta 2 agonist
46
What are some things that redistribute potassium extracellularly?
Acidosis
Succinylcholine
Beta-blockers
Hyperkalemic periodic paralysis
47
What is the MOST common electrolyte disorder in clinical practice?
HYPOkalemia
48
How fast should you administer K in a peripheral line? How fast in a central line?
Peripheral: 10 mEq per hour
Central: 20 mEq per hour
49
What is Normal serum sodium?
135-145
50
What is the most abundant extracellular cation?
Sodium
51
at what sodium level should you delay surgery?
< 130 mEq/L
52
How slowly should you correct disorders of sodium balance?
No more than 1-2 mEq/L/hr
53
What can happen if you treat hyponatremia too quick?!
Causes fluid to shift from ICF to ECF ~ this can produce central pontine myelinoysis
54
What can happen if you treat hypernatremia too quick?
Causes fluid to shift from ECF to ICF ~ this can produce cerebral edema
55
What is factor 4 in the coagulation pathway?
Calcium
56
What is a normal plasma Ca level? (Total and ionized)
Total: 8.5-10.5
Ionized: 4.65-5.28
57
What is the most abundant electrolyte in the body?
Calcium
58
Calcium antagonizes who’s effects at the neuromuscular junction?
Magnesium’s!
59
How does acidosis affect calcium concentration?
Increases ionized calcium
60
How does alkalosis affect ionized calcium?
It decreases ionized calcium
61
What hormone raises Ca?
Parathyroid hormone
62
What hormone reduces serum Ca?
Calcitonin
63
What gland releases calcitonin?
Thyroid gland
64
What are some presentations of hypocalcemia?
Skeletal musc cramps
Nerve irritability
Laryngospasm
Mental status changes ~ seizures
Chvosteks sign
Trousseau sign
65
How does hypocalcemia affect the EKG?
Prolonged QT
(Maybe it takes long to get enough Ca to initiate contraction)
66
What are some presentations of hypercalcemia?
Nausea
Abdominal pain
HTN
Psychosis
67
How does hypercalcemia affect the EKG?
Short QT
(Maybe there is an abundant supply so it doesn’t take as long?)
68
What is chvostek’s sign?
Tapping of angle of jaw ~ facial contraction
(Chvostek = cheek)
69
What is trousseau Sign?
Upper BP cuff is inflated abound SBP for 3 mins ~ decreased blood flow accentuates neurmuscular irritability ~ muscle spasms of hand and forearm
70
Loss of deep tendon reflexes is the result of what?
Hypermagnesemia
71
What is a normal Mg level (total)?
1.7-2.4
72
Which electrolytes does Mg antagonize the effects of?
Calcium!
73
What is the dose of magnesium for pre-eclampsia?
4 gram load over 10-15 mins
1 g/h for 24 hours
74
What are some common causes of Hypomagnesemia?! <1.8 mg/dL
Poor intake
ETOH
Diuretics
Illness
Common with hypokalemia
75
What are some common causes of hypermagnesemia? > 2.5 mg/dL
Excessive administration
Renal failure
Adrenal insufficiency
76
What is the EKG finding with Hypomagnesemia?
Torsades and/or prolonged QT
77
What is the EKG finding with Hypermagnesemia?
Heart block
78
What are the S&S of a Mg level of < 1.2?
Tetany
Seizures
Dysrhythmias
79
What are the S&S of a mag level 1.2-1.8?
Neuromuscular irritability
Hypokalemia
Hypocalcemia
80
What happens at a Mg level of 2.5-5 mg/dL?
Nothing typically
81
What happens at a Mg level of 5-7?
Diminished tendon reflexes
Lethargy
Flushing
N&V
82
What happens at a Mg level of 7-12 mg/dL?
Loss of deep tendon reflexes
Hypotension
EKG
Somnolence
83
What happens at a Mg greater than 12 mg/dL?
Resp depression
CHB
Arrest
Coma
Paralysis
84
How does magnesium work as an opioid sparing drug?
Antagonizes the NMDA receptor
85
What equation states that a solution’s pH is a function of the ratio of dissociated anion to the non-dissociated acid?
Henderson-Hasselbach
pH = pK + log [A-]/[HA]
86
What is the most important buffer of the blood?
Bicarbonate!
87
What is the second most important buffer of the blood?
Hemoglobin!
88
What is a normal anion gap?
8-12
89
What are examples of metabolic acidosis with a NORMAL anion gap?
HARD UP
H: hypoaldosteronism
A: acetazolamide
R: renal tubular acidosis
D: diarrhea
U: uretosigmoid fistula
P: pancreatic fistula
90
What is consider a increased anion gap?
> 12
91
What are examples of metabolic acidosis with an increased anion gap?!
MUDPILES
M: methanol
U: uremia
D: diabetes ketoacida
P: paraldeyde
I: isoniazid
L: lactate
E: ethanol
S: Salicylates
92
How does acidosis affect the heart?
Increase in P50 (shift to the right)
Increase in SNS
Increase risk dysrhythmias
Decreased contractility
93
How does alkalosis affect the heart?
Decreased P50 (left=love)
Decreased coronary blood flow
Increase risk of dysrhythmias
94
What type of acid-base disorder does untreated pain result in?
Resp alkalosis
95
At what pH should you mechanically ventilate?
< 7.20
96
In ACUTE resp distress, for every 10 mmHg increase in PaCO2 ~ pH decreased by what?
0.08
97
In CHRONIC resp acidosis, for every 10 mmHg increase in PaCO2, pH decrease by what?
0.03
98
When do you have CO2 narcosis?
PaCO2 > 90 mmHg
99
What is the most common cause of respiratory acidosis?
Hypoventilation
100
What is the most common cause of resp alkalosis?
Mechanical ventilation.
101
When should your treat resp alkalosis? It specially in a spontaneously ventilating patient? And how should you treat it?
pH> 7.6
Give sedation
102
What are the two most common causes for metabolic alkalosis?
Vomiting
Massive blood transfusion
103
How do you treat metabolic alkalosis?
Acetazolamide
Spironolactone (mineralcorticoid antagonist)
Dialysis
104
What is the calculation for determining fluid maintenance?
4:2:1
4 mL/kg for 1st 10 kg
2 mL/kg for 2nd 10 kg
1 mL/kg for subsequent kg of body weight
105
How do you calculate fluid deficit?
Fasting hrs x hourly maintenance
106
How do you calculate third space for very minor trauma?
1-2 mL/kg
Orofacial surgery
107
How do you calculate third space for minimal trauma?
2-4 mL/kg
Hernia
108
How do you calculate third space for moderate trauma?
4-6 mL/kg
Major NON-abd surgery
109
How do you calculate third space for severe trauma?
6-8
Major abdominal surgery
110
How much crystalloid is given to replace blood loss?
3:1
111
How much colloid to replace for blood loss?
1:1
112
What happens with too little fluid resuscitation?
Decreased volume (hypovolemia)
Decreased O2 delivery
Decreased organ perfusion
Hemoconcentration
Myocardial ischemia
PONV
Renal impairment
113
What happens with too much volume resuscitation?
Excessive volume
Decreased O2 delivery (d/t microvascular congestion)
Impaired glycocalyx
Hemodilution
Impaired wound healing
Pneumonia
Liver congestion impaired gut fx
114
On what part of the Starling curve, does additional fluid increase sarcomata stretch? Aka is responsive
Slope
115
Which part of the starling curve describes the optimal balance b/t circulating volume and myocardial performance?
Plateau
Preload INDEPENDENCE
116
Which part of the frank starling curve impairs myocardial performance?
Overshoot
117
What are some preoperative components of the recommended ERAS?
Pre admission counseling
Fluid and carbohydrate loading
fasting
Abx prophylaxis
Avoidance of premedication
Thromboprophylaxis
118
What are some intraoperative components of the ERAS?
Mid-thoracic epidural
Short-acting drugs
Goal-directed fluid therapy
Normothermia
PONV prophylaxis
No surgical drains (if possible)
119
What are some post operative components of the ERAs protocol?
Mid-thoracic epidural
Opioid-sparing analgesia
Judicious fluid administration
PONV prophylaxis
No OG/NG
Encouraging gut motility
Early oral intake
Early removal of catheter early ambulation
120
What are the common causes of hypercalcemia?
Hyperparathyroidism and cancer
