Fluids, Electrolytes, and Goal-Directed Therapy Flashcards
ICV represents
2/3 of TBW
ECV represents
1/3 of TBW
perioperative fluid mamangment involves:
- maintaining intravascular volume
- augmenting CO
- maintaining tissue perfusion
- promoting oxygen delivery
- correcting and maintaining electrolyte balance
- enhancing the microcirculatory flow
- facilitating the delivery of nutrients
- clearance of metabolic waste
TBW in an average adult represents
60% of lean body mass
primary cation and anion in the ECV
sodium, chloride
primary cation and anion in the ICV
potassium, phosphate
resting membrane gradient for these electrolytes is maintained by the
Na and K ATPase
cell membrane is permeable to
water
as a result of the ICV and the ECV maintain a state of osmotic equilibrium
daily fluid volume required to maintain TBW homeostasis
25-35 mL/kg per day or 2-3 L/day
ECV is further divided into
intravascular compartment
interstitial compartment
interstitial compartment represents
3/4 of the ECV
intravascular compartment represents
1/4 of the ECV
ECV is also composed of a small amount of
transcellular fluid:
- CSF
- GI secretions
- intraocular fluid
- synovial fluid
Transcellular fluids are anatomically __ from the fluid dynamics that impact the remaining ECV, therefore they are considered ___
isolated; nonfunctional
Capillary hydrostatic pressure (Pc)
is the intravascular blood pressure, driven by the force of the CO impacted by the vascular tone
Interstitial fluid pressure (Pif)
is the hydrostatic pressure of the interstitial space
Pif of most tissues is slightly __ ; this is thought to be d/t the contraction of __ vessels in the interstitum
negative; lymphatic
what has a slightly positive Pif?
rigid or encapsulated tissues of the kidneys, brain, bone marrow, and skeletal muscle
plasma oncotic pressire (πp)
is the osmotic force of collodial proteins of the vasular space
interstitial oncotic pressure (πif)
is the osmotic force of the colloidal proteins within the interstitial space
what protein is the primary determinant of both capillary and interstitial oncotic pressures?
albumin
Increase in Pc and πif favor
filtration of fluid into the interstitial space
increase in Pif and πp favor
absorption of fluid into the intravascular space
Increased Kf favors
filtration
A sigma of 0 indicates
that the endothelium is freely permeable to the substance
a sigma of 1 indicates
that the endothelium si completely impermeable to the substance
positive net filtration favors fluid exudation into
the tissues
net filtration tends to be slightly __ at the arterial end of capillaries and slightly __ at the venous end
positive; negative
overall balance of filtration pressures within capillaries of the entire body is slightly
positive
at what rate is the intravascular volume being filtered into the interstitial space ?
2 mL/min
volume is returned to the intravascular space via the
lymphatic system
glycocalyx
is a gel layer on the luminal surface of the vascular endothelium that plays an important role in:
- transcapillary fluid exchange
- microcirculatory flow
- blood component rheology
- plasma oncotic pressure
- signal transduction
- immune modulation
- vascular tone
glycocalyx diameter
0.1 to 0.2 micrometers
glycocalyx is composed of a matric of
glycoproteins, polysaccharides, and hyaluronic acid
dynamic barrier ionically repels __ charged polar compounds in addition to __ __
negatively; blood componenets
binding to circulating plasma albumin, the glycocalyx also helps preserve __ __ __ and __ capillary permeability to water
capillary oncotic pressure; decrease
this is known as the double barrier effect
the glycocalyx is thought to contain ___ ___ whose binding sites are enclosed in the matrix, helping prevent leukocyte adhesion
inflammatory mediators
other functions of the glycocalyx
- scavenging of free radicals
- binding and activation of anticoagulation factors
- signal transduction that helps regulate local vasoactive responses to mechanical stress
normal daily alterations in TBW are regulated by
RAAS (renin-angiotensin-aldosterone system)
ADH (antidiuretic hormone)
ANP (atrial natriuretic peptide)
what is one of the primary determinants of serum osmolarity and water transport?
sodium
RAAS is an important regular of __ homeostasis
sodium
what detects hypotension in the RAAS?
- intracardiac
- renal afferent arteriole barorecpetos
juxtaglomerular cells of the kidney release
the enzyme renin
interaction of circulating renin with the precursor __ causes the cleaving of __ to the active substance __
angiotensinogen; angiotensinogen; angiotensin I
angiotensin I exerts local
vasoconstrictor activity
primary role of angiotensin I
is as a precursor for the more potent angiotensin II
this change occurs in the __ as a result of ACE acting as a catalyst for the conversion of angiotensin I to II
lungs
angiotensin II directly stimulates what to reabsorb sodium and water?
renal tubules
angiontensin II is a potent
vasoconstrictor
angiotensin II causes the __ __ to release aldosterone , which further stimulates Na and water retention by the kidneys
adrenal cortex
secretion of ADH contributes to an increase in
urine concentration and osmolarity
the ADH pathway functions primarily to regulate
water balance
Posterior pituitary gland releases __ which causes __ channels within the kidney to transiently reabsorb large quantities of __
ADH; aquaporin; water
ADH also plays a role in preserving blood pressure by
acting as a potent arterial vasoconstrictor
stretch receptors in the cardiac __ walls stimulate the release of __ from cardiac myocytes as a result of increased preload or hypervolemic state
atrial; ANP
the release of ANP stimulates
the kidney to release Na and water, thus reducing circulating blood volume and offloading the heart
ANP also produces __ responses in the afferent and efferent renal arterioles to __ the GFR, and it inhibits the release of __ & __
vasoactive; increase; renin; ADH
during periods of decreased preload, atrial receptors __ the release of ANP
inhibit
crystalloid infusions are preferable for resuscitation of
dehydration conditions
dehydration examples
- prolonged fasting states
- active GI losses
- polyuria
- hypermetabolic conditions
crystalloids are preferred for their lack of __ potential, ease of metabolism, and __ clearence
allergenic; renal
isotonic crystalloids are distributed evenly throughout the __ space, their ability to __ plasma volume is transient
extracellular; expand
crystalloids favor filtration approx ___ into the interstitial space
75%-80%
what is the most common crystalloid solution administered worldwide?
0.9% NS
high chloride load contributes to
- acid-base imbalances
- hyperchloremic metabolic acidosis
normal physiologic concentration of Na and Cl is
Na is much higher than Cl
NS is roughly equal concentrations of
Na and Cl
hyperchloremia has a substantial impact on
renal function
increased Na load introduced by large volumes of NS shown to cause
increased salt and water retention, hemodilution, and interstitial edema well into the postop period
NS in modern anesthesia can be given in __ volumes to __ patients
small; neurosurgical
NS is the preferred fluid for patients at risk for
cerebral edema
NS may also be indicated in fluid management of patients with
anuria and ESRD who cannot excrete K content of a more balanced crystalloid solution
B/c NS does not contain K, avoid worsening hyperK, safe choice
LR contains K thats why its no good for ESRD pt’s
Hypertonic solutions (3% or greater) are sometimes used in low dose infusions in
trauma and head injury paitents
help w/ ICP improve CPP, osmotic effect: draw H2O out of braincells
volume-expanding effect, help CO, antiinflammatory effects, preservation fo cerebral blood flow
hypertonic solutions promote
volume expansion that mobilizes intracellular and interstitial fluids into the intravascular space
risks for hypertonic solutions
- vascular irritation
- sudden and pronounced fluid shift into the intravascular space
- potential for dehydration of neural cells leading to osmotic demyelination syndrome
LR contains
sodium lactate as a bicarb substrate or buffering agent
LR is not recommended for
- large volume administration in diabetic patients b/c byproducts of hepatic metabolism of lactate can result in gluconeogenesis
lactate is metabolized into bicarb in the liver –> metabloic alkalosis
T/F NS is more effective as a resuscitative fluid administration than LR for preserving intravascular volume
FALSE
LR is mildly __ and may cause transient serum hypo-osmolarlity and associated ___ __
osmolarity=meausre of the concentration of solute particles ina solution
hypotonic; cerebral edema
LR is contraindicated in patients with
TBI or other neurovascular insults
LR contains __ and is contraindicated in infusions with citrated (preservative used in blood products) d/t the risk of coagulation
calcium
citrate binds with calcium, risk for calcium chelation
preventing coagulation and preserving the viability of blood products
plasmalyte-A, Normosol-R, Isolyte S
most isotonic of the balanced solutions
what does plasmalyte use as alkalinizing buffers?
- sodium gluconate
- sodium acetate
colloids are suspensions of __-molecular weight molecules in __ solutions
high; electrolyte
colloids produce
intravascular volume expansion by directly increasing πp and interacting with the endothelial glycocalyx to decrease transcapillary permeability
colloids are effective for their plasma volume __, and are often used perioperativley for their __-__ effects compared to crystalloids
expansion; fluid-sparring
what is the only naturally occurring colloid solution available?
albumin
how are colloid infusions classified?
- molecular weight
- concentration
- half-life
what is the oldest artificial colloid?
Dextran
dextrans characteristics
- high-molecular-weight (40-70 kDa)
- derived from bacterial metabolism of sucrose
- first manufactured in 1940’s
- markedly hyperosmolar
- 1/2 life of 6-12 hours
Dextrans associated with a variety of coagulopathic effects d/t
- Von Willebrand factor
- activation of plasminogen
- inerference with platetlet agreggation
Dextrans cause
acute RF
indirect hyperosmotic RI and direct RT damage as a result of accumulation
dextrans may also adhere to the surface of __ & __ and interefere with cross matching of bood products
platelets & RBCs
T/F Dextrans are still used in clinical practice
False
d/t the propensity to cause acute RF, and induce anaphylaxis, and coagulopathy
Genlatins are __ colloids derived form __ __
synthetic; bovine components
Gelatins characteristics
- molecular weight of 30-35 kDa
- shorter half-life 2-4 hours
- limited duration of plasma expansion
Gelatins risks
- interfere with platelet function
- cause nephrotoxicity
- high propensity of causing anaphylaxis
Use of gelatins in clinical practice is
cautioned
HES (hyroxylethyl starches) can cause allergic reactions in people who are allergic to
potatoes, maize, sorghum, and other components
Hydroxyethyl starches (HES) are __ macromolecules derived from __ __
synthetic; starchy plants
how does HES provide prolonged volume expansion?
high C2/C6 ratio indicated HES will be difficult to metabolize
where is HES widely used?
European union
first-generation HES are associated with
- dose-dependent coagulopathy b/c of hemodilution and binding of clotting factors
- interference of platelet adhesion
- inhibition of fibrin polymerization
- alterations in plasma viscosity
HES can also accumulate for form interstitial colloid deposits in subcutaneous and other organ tissue than can lead to severe..
pruritus
nephrotoxicity
FDA issued a black box warning for
HES in 2013 to notify for public risks of renal injury and increased mortality
the PRAC and EMA issued a sudden recommendation to fully suspend all
HES solutions in jan 2018
albumin is a
fractionated blood product produced from pooled human plasma
molecular weight of 65-69 kDa
small volumes of __ provide __ degree of intravascular resuscitation as compared to equal or greater volumes of crystalloid
albumin; greater
albumin is __ treated to __ pathogens and eliminate the risk of dx transmission
heat; inactivate
T/F Albumin preparation is significantly more costly than crystalloid solutions
true
T/F Albumin does not carry a risk for anaphylaxis
false
albumin is a carrier for a # of protein-bound ionic substances including:
- drugs and their metabolites
- electrolytes
- enzymes
- hormones
T/F albumin has a negative electrostatic charge
true
Donnan effect
albumin molecules bind ions, which increase plasma osmolarity and intravascular volume
stimulation of osmotic and autonomic afferent nerves in the area of surgical incision triggers the activation of
hypothalamic-pituitary axis (HPA)
the hypothalamus releases __ which then elicits the creation and release of cortisol from the __ __
ACTH; adrenal cortex
cortisol stimulates
protein catabolism, hepatic gluconeogenesis, and glycogenolysis, and increased hepatic production and release of plasma proteins
hyperglycemia is a major risk factor for damage or destruction of the
endothelial glycocalyx
hyperglycemia also contributes too
- impaired wound healing
- contributes to osmotic diuresis
- interferes with immune response
sympathetic stimulation in combination with hyperosmolar conditions triggers the release of
ADH
most beneficial effect of cortisol
the anti-inflammatory effect it exerts by inhibiting the production, release, and vascular aggregation of inflammatory mediators
“third space” was introduced in the 1960’s as
a nonfunctional component of the ECV
EBL ratio of crystalloid to blood
3:1
evidence demonstrates that actual observed ratio is less than
2:1
4-2-1 calculation
0-10kg: 4mL/kg/hr
11-20kg: 2mL/kg/hr (for the first 10kg x4, next 10kg x2)
> 20kg: 1mL/kg/hr (for the first 10kgx4, next 10kgx2, everything after that x1)
estimated fluids deficit
estimated fluid deficit = maintenance requirment x fasting hrs
superficial trauma (orofacial)
1-2 mL/kg/hr
minimal trauma (herniorrhaphy)
2-4 mL/kg/hr
moderate trauma (major nonabdominal surgery or laparoscopic abd surgery)
4-6 mL/kg/hr
severe trauma (major open abd surgery)
6-8 mL/kg/hr
consequences of under resucitation
- hypovolemia
- decreased microvascular perfusion leading to decreased O2 delivery
- reduced tissue perfusion
- end-organ complications
- PONV
- renal dysfunction
- myocardial ischemia
- hemoconcentration leading to increased blood viscosity, thrombotic events
consequence of overresuscitation
- vascular overload, acute CHF
- microvascular congestion leading to decreased oxygen delivery
- endothelial glycocalyx disruption
- decreased tissue oxygenation
- altered coags and potential hemorrhage
- hemodilution leading to anemia, thrombocytopenia, altered viscosity
- decreased gut motility
- increased infection rates
- decreased organ perfusion
- increased EVLWI? and prolonged post-op MV
- increased incidence of VAP
- hepatic congestion and dysfunction
- abd compartment syndrome
aim of GDFT is
utilize individualized hemodynamic endpoints to support oxygen transport balance by minimizing O2 demands and optimizing CO, tissue oxygenation, capillary and macrovascular flow, oxygen, nutrient delivery, and end-organ perfusion
GDFT protocols begin with a baseline assessment of target __ measures followed by the administration of a __ volume fluid bolus
hemodynamic; small (200-250)
basis of the frank-starling mechanism is the relationship between
LVEDP and myocardial contractility (SV)
the FS is highly effective until
the point at which the sarcomere cannot generate additional force
further increases in preload after this threshold will generate no further increases in SV
limitations of dynamic measures
- SV (spontaneous ventilation)
- small TV
- open chest
- sustained arrhythmias
- PEEP
- right heart dysfunction
ERAS means
enhanced recovery after surgery
ERAS was initially developed for
colon surgery
primary cellular injury can
impair O2 and nutrient delivery to vital organs resulting from local and global perfusion changes
secondary cellular injury
process caused by the stress response associated with surgery that results in the release of local inflammatory mediators or hormones
combination of primary and secondary cellular injury result in
delayed wound healing and gut dysfunction and may lead to postsurgical complications
two fundamental elements that affect postsurgical outcomes are attributed to
fluid therapy and effective pain managment
BBB has limited permeability
to ionic solutes
normal values
CO
CI
EVLWI (extravascular lung water index)
FTc (corrected flow time)
GEDI (global end diastolic index)
change in peak pressure
PPV/ change in pulse pressure
PVI (plethysmography variability index)
ScvO2 (central venous O2 saturation)
SPV (systolic pressure variation)
SV/SVI
SVR/SVRI
Svo2 (mixed venous O2 saturation)
SVV
4-8 L/min
2.5-4 L/min/m^2
3-7 mL/kg
330-360 ms
680-800 mL/m^2
> 12% predicts preload responsiveness
> 13% predicts preload responsiveness
> 14% predicts preload responsiveness
normal value 70% (blood in the SVC)
> 14% predicts preload responsiveness
SV: 60-100 mL/beat, SVI: 33-47 mL/m^2/beat
SVR: 800-1200 dynes-sec/cm-5/m^2 SVRI: 1970-2390
60-80% (blood in PA measured by PAC)
> 13% predicts preload responsiveness
changes in water concentration are largely d/t
sodium
limited permeability in the BBB prevents the equilibration of __ active ionic solutes between ECV & ICV
osmotically
most important osmotically active substance influencing the water content of the brain tissues?
sodium
sodium imbalances reflect an impaired
concentration between water and Na
hyponatremia
the intracellular environment is hyperosmolar compared to the ECV leading to an influx of water into the ICV
most significant consequences of hyponatremia is
cerebral edema
whos at an increased risk of brain damage resulting from hyponatremia?
menstruating women
believed that progesterone and estrogen inhibit the efficiency of Na-K-ATPase pump
female sex hormones may facilitate the movement of water into the brain through the mediation of ADH
what is the most common electrolyte abnormality in hospitalized patients?
hyponatremia
development of hypervolemic hyponatremia in patients with ___ & ___ is assoicated with an increased risk of death
CHF; cirrhosis
bonus polycystic kidney dx
rapid correction of hyponatremia particularly in patients with chronic hyponatremia can result in
- seizures
- spastic quadriparesis
- coma d/t osmotic demyelination
vasopressin receptor antagonists are available to treat
hypervolemic or euvolemic hyponatremia
medications antagonize arginine vasopressin by inhibition of renal V1a, V1RA, V2, & V3RA receptors. result in increased free water excretion by the kidneys
initial treatment of hyponatremia usually includes
fluid restriction & diuresis
myelinolysis
Central pontine myelinolysis
can lead to disorders of the upper neurons, spastic quadriparesis, pseudobulbar palsy, mental disorders, death
serum Na concentrations should be increased no more than ___ mEq/L per hour
1 to 2
whos at risk for myelinolysis ?
hyponatremic greater than 48 hrs, orthotopic liver tx, hx of alcohol abuse
symptomatic patients can infuse
3% saline at a rate of 1 to 2 mL/kg/hr
what is the usual cause of hypernatremia
impaired water itnake
If the hypernatremia is acute, water deficits can be replaced relatively __ with __ solution
rapidly; hypotonic
if chronic hypernatremia is accompanied by volume __, the volume disorder is corrected first with __ __
depletion; isotonic crstalloids
once the circulating volume is restored, __ solutions are used to correct the water deficit
hypotonic
plasma Na should be decreased by __ to __ mEq per hour until to the patient is clinically stable
1 to 2
__ within these compartments are in large part responsible for the resting membrane potential
K
Homeostasis is maintained by absorption of K from
- GI tract
- renal excretion
- reabsorption into the peritubular capillary network
renal regulation of K is dependent on
- the concentration gradient between the distal tubules and collecting duct relative to the peritubular capillary network
- the distal convoluted tubular flow rate and Na concentration
- aldosterone concentration
- changes in pH
aldosterone has a potent effect on __ levels
K
hyperkalemia causes adrenal cortical synthesis and the release of
aldosterone
which promotes potassium excretion from the distal renal tubules
hypokalemia is defined as
less than 3.5
redistribution of K from the ECV to the ICV can lead to
hypokalemia
hypokalemia can result from
GI losses, renal loss, intracellular shift, increased nonrenal losses, endocrinopathies, and poor intake
what is the most common electrolyte abnormality to come across in clinical practice?
hpokalemia
what promotes the movement of K into the ICV
B-adrenergic stimulation, insulin, and alkalosis
hypokalemia is __ times more likely to occur with patients on thiazide diuretics & __ as high for men than woman
11; twice
symptoms of mild hypokalemia
- palpitations
- skeletal muscle weakness
- muscle pain
symptoms of K < 2.5
- paresthesia
- depressed deep tendon reflexes
- fasciculations
- muscle weakness
- altered level of consciousness
patients with CHF & ischemia, hypokalemia increases the potential for
dysrhhythmias
common cardiac dysrhythmias present with hypokalemia are
- first-degree heart block
- second-degree heart block
- a-fib
- vfib
- asystole
ECG abnormalities with hypokalemia include
- ST depression
- flattened T-wave
- the presence of U wave
What’s the fastest K can be given? and why?
40mEq per hour if levels are less than 2.0
maximum rate of 10-20mEq is recommended to avoid in
iatrogenic hyperkalemia? i think the book meant hypokalemia
IV K can be replaced with __ because __ makes it difficult for the kidney to conserve K
chloride; hypochloremia
hyperkalemia is defined as serum K
< 5
occurs less commonly compared to hypokalemia if renal causes are excluded
what meds increase ECV K
- beta blockers
- ACEIs
- ARBs
causes of hyperkalemia
- impaired renal excretion
- high intake of K
- shift of K from the ICV to the ECV
hyperkalemia can lead to increased __ production and apoptosis
LA
decreasing angiotensin, ___/___ can cause hyponatremia and hyperkalemia
ACEIs/ARBs
what is laboratory artifact?
pseudohyperkalemia
pseudohyperkalemia results from
hemolysis of the blood sample, leukocytosis, thrombosis, prolonged fist clenching during blood drawing
treatment of hyperkalemia accomplishes 3 physiologic effects
1.) stabilization of the cardiac membrane
2.) driving K from ECV to ICV
3.) removal of K from the body
treatment of hyperkalemia
10 units of regular insulin
1 ampule of D50
a complication can be hypoglycemia
what percent of calcium is found in the bones as hydroxyapitate ?
99%
remaining 1% of calcium exists in
the plasma and body cells
calcium as a second messenger is critical for functions of
muscle contractions, release of hormones, and neuotransmitters
calcium plays an important role in
blood coagulation, muscle function (myocardial contractility)
calcium in the ECV is found in 3 distinct fractions
- 50% is ionized Ca and is the physiologically active portion
- 10% of Ca is bound to anions
- 40% bound to plasma proteins primarily albumin
total of circulating Ca within the blood is
9.0 to 10.5 mg/dL
serum Ca levels are maintained by the release of inhibition of
PTH but also by vitamin D and calcitonin
causes of hypocalcemia
hyperventilation and massive rapid transusion
hypervent causes respalkalosis, decr conc of ionized Ca by incr bind alb
hyperventilation leads to __ pH, which facilitates __ protein binding of calcium, thus __ serum ionized Ca
increased; increased; decreasing
citrate is a
preservative added to pRBCs
citrate chelates or binds to calcium, __ serum Ca available for physiological reactions
decreasing
massive rapid blood transfusions can cause acute
hypocalcemia
treatment of hypocalcemia involves the infusion of
Ca salts
cause signif venous irritation and tissue necrosis as compared to Ca gluconate
Ca gluconate preparation
10 mL of 10% Ca gluconate over 10 mins followed by an infusion of 0.3 - 2 mg/kg per hour
second most common cause?
malignancy
hypercalcemia results usually from
movement of ca from bone to the ECV
which exceeds the kidney to excrete the Ca
what accounts for more than 1/2 of the cases of hypercalcemia?
primary hyperparathyroidism
treatment of hypercalcemia involves
volume expansion with NS, increase renal excretion of Ca
addition of a loop diuretic
also been used to treat hypercalcemia
- bisphosphonates
- mithramycin
- calcitonin
- glucocorticoids
- phosphate salts
HD is an acute treatment to rapidly lower
serum Ca
Mag is the __ most abundant intracellular cation
second
what percent of Mag is stored in muscle and bone?
within the cells?
and within the serum?
40-60%
30%
1%
importance of mag in its role as a cofactor in
- enzymatic reactions (involving energy metabolism)
- protein synthesis
- neuromuscular excitability
- function of the Na-K-ATPase pump
regulation of Mag occurs where?
intestines and kindeys
hypomagnesemia increases cardiovascular death in men and women by what percentage?
8% & 16%
hypomagnesemia has an __ effect on the Na-K-ATPase pump resulting in __ ICV of K
inhibitory; decreased
IV infusion of mag can relieve severe __ , and it can decrease __ __
bronchospasm; postoperative pain
hypo magnesium causes
increased renal or GI losses or poor mag intake and/or medications
ECG changes seen with hypomagnesemia
- flat T waves
- presence of U waves
- prolonged QT interval
- widened QRS complexes
- atrial and ventricular arrhythmias
treatment of hypomagnesemia
IV 1 to 2 g of mag sulfate over 5 mins followed by 1 to 2 g per hour
hypermagnesemia is the most commonly the result of
iatrogenic causes
hypermagnesemia can result from
- treatment of preeclampsia
- preterm labor
- ischemic heart dx
- cardiac dysrhythmias
symptoms of hypermagnesemia
depression of the peripheral and central NS, hypotension, QRS segment widening, PR & QT segment prolongation, heart block, and cardiac arrest
magnesium potentiates the action of
NDMR
treatment of hypermagnesemia
- d/c mag
- in urgent situations (brady, heart block, resp depression) calcium chloride should be used as an antagonist
majority of phosphate is located in
bone 85%
small amount of phosphate is located in
plasma, phospholipids, phosphate esters, inorganic phosphate (which is the ionized form)
intracellular phosphate has numerous metabolic effects such as
component of ATP, and 2,3 -diphosphoglycerate, also acts as a buffer in the regulation of acid/base imbalance
the concentration of phosphate in plasma in inversley proportional to
calcium
hypophosphatemia is defined as
< 2.0 mg/dL
hypophosphatemia causes
increased renal excretion & intestinal malabsorption
resp alkalosis can also cause low phosphate levels how?
accelerated use of ATP by cells
hypophosphatemia decreased 2-3-DPG is in RBC’s causing what shift in ODC
leftward
hyperphosphatemia is defined as
greater than 4.7 mg/dL
majority of phosphate exists within the ECV, and cellular __ is a leading cause
destruction (exp. metastatic dx)
increase phosphate levels cause __ CA levels
decreased
so symptoms are synonymous with hypocalcemia
