IV, Fluids, Blood Flashcards
why are NPO guidelines enforced
due to risk of pulmonary aspiration
mendelson syndrome
acute chemical pneumonitis caused by the aspiration of stomach contents in patients under general anesthesia
Enhanced Recovery After Surgery (ERAS) related studies showed that a reduced fasting interval produced
lower residual gastric volume and higher gastric pH.
Prolonged fasting can contribute to
hypovolemia, hypoglycemia, and anxiety
adult traditional NPO guidelines:
-solids
-medications
No solids for 8H pre-op
most medications can be continued with a small sip of water (excluding some cardiac and diabetic meds)
patients at ↑ risk for aspiration
Renal failure, hepatic dysfunction, ascites
Head injury, increased ICP, decreased LOC, cerebral palsy
Anorexia, esophageal disorders, diabetes, delayed gastric emptying, difficulty swallowing
pediatrics 2 hour NPO
clear liquids (water, apple juice, clear juice drinks, clear gelatin, clear broth, ice popsicles, and Pedialyte)
pediatrics 4 hour NPO
human breast milk
pediatrics 6 hours NPO
Infant formula, nonhuman milk, light meal:
pediatrics 8 hours NPO
“full” meal, carbonated drinks
ERAS
Goals
patient-centered, evidence-based, multidisciplinary team developed pathways for a surgical specialty and facility culture
goal: reduce the patient’s surgical stress response, optimize their physiologic function, and facilitate recovery
ERAS care pathways
form an integrated continuum, as the patient moves from home through the pre-hospital / preadmission, preoperative, intraoperative, and postoperative phases of surgery and home again.
ERAS program fasting recommendation
minimal fasting that includes a carbohydrate beverage two hours before anesthesia,
ERAS Program key elements
pt/family education, patient optimization prior to admission, minimal fasting that includes a carbohydrate beverage two hours before anesthesia, multimodal analgesia with appropriate use of opioids when indicated, return to normal diet and activities the day of surgery, and return home
4-2-1 Rule
guide for hourly maintenance
hourly fluid maintenance for 70kg patient
NPO deficit
Equals the number of hours the patient is NPO x the hourly maintenance rate
Example: 8 hr x 110 mL = 880 mL
NPO fluid administration
50% first hour
25% second hour
25% third hour
output
urine
respiratory tract
evaporative losses
losses due to wounds or bleeding
insensible losses
3rd space fluid losses
Tissue manipulation & surgical trauma supports movement of fluid from the ECF compartment into non-functional compartments
Small Incision/minimal trauma
4-6 ml/kg/hr
Moderate Incision/moderate trauma
6-8 ml/kg/hr
Large/Incision/severe trauma
8-10 ml/kg/hr
Major vascular case/extreme trauma
10-12 ml/kg/hr
crystalloids contain
electrolytes dissolved in water or dextrose and water
examples of crystalloids
0.9% NaCL
Lactated Ringers
Colloids
Characteristics
natural or synthetic molecules
somewhat impermeable to vascular membrane
determine colloid osmotic pressure
(balances water distribution b/t intravasc & interstitial spaces)
examples of colloids
5% albumin
6% hydroxyethyl starch
When to use 0.9% NS
for most neurological or renal patients; blood administration
plasmalyte contains…
Mg, Acetate, Gluconate
Lactated ringers contains…
Na, Cl, K, Ca
D5W
contains ___ dextrose per liter
5 gm
used for volume expansion; each has limitations
Dextran, hespan, hetastarch
Balance Salt Solutions (BSS) are fluids that have an electrolyte concentration similar to
ECF.
Contains more chloride than ECF
Normal saline solution
Good choice for renal (diabetic) and neurosurgical patients
Normal saline
too much NaCl can cause which metabolic disorder?
hyperchloremic-induced metabolic acidosis
LR contains
dextrose, K, Ca, Na, Cl, and Lactate
Prevention of hypoglycemia in neonates and pediatric patients
Dextrose containing solutions
Used in conjunction with insulin infusions
dextrose containing solutions
Hyperglycemia is associated with
increased risk for ischemic neurologic injury.
Beneficial in fluid resuscitation from shock/trauma and major surgical Losses
hypertonic saline
hypertonic saline indications
Major surgical procedures: aortic, radical cancer surgeries
Shock
Slow correction of hyponatremia
TURP syndrome
Reduce perioperative edema
Reduce ICP
hypertonic saline effects
Pooled plasma in saline
albumin
albumin characteristics
Highly soluble, globular protein
accounts for 70-80% of the colloid osmotic pressure of plasma
5% albumin can be used for
rapid intravascular volume expansion
25% albumin can be used for
hypoalbuminemia
Albumin intravascular half-life
> 24 hours
Most perioperative volume deficits are
extracellular fluid
Crystalloid solutions eventually equilibrate ____________ therefore ____________
between plasma & interstitial space
more is needed to maintain intravascular volume
ABO compatibility for albumin and plasma
not needed
Albumin heat treated at 60 degrees C for 10 hours eliminates
possibility of transmission of blood-borne disease
do albumin and plasma derivatives contain coagulation factors?
no
Associated with increased mortality in critically ill patients
albumin and plasma derivatives
synthetic plasma expanders
dextran, Hetastarch, Voluven, Hextend, Hespam
Composed of polymerized glucose molecules
dextran
dextran Intravascular half-life
6 hours
potential complications of dextran
synthetic polymer
Hextend and Hespan
intravascular half life of Hextend and Hespam
more than 24 hours
Hextend/Hespan infusion max
Infuse no more than 1000 cc (20 ml/kg/day)
Higher volumes of Hextend/Hespan
Risk
bleeding complications
d/t ⬇️ factor VIII/vWf, platelet defects, fibrin clots
Anaphylactoid reactions have been reported with both
dextran and hetastarch, but much rarer with hetastarch
ultimate goal of blood transfusion is to
maintain oxygen-carrying capacity to the tissues
for blood loss you can replace with ….
Until ….
crystalloids or colloids to maintain intravascular volume
until risk of anemia outweighs the risk of the blood transfusion
healthy patient without cardiac disease can usually tolerate decrease in Hgb and Hct to
Hgb to 7 - 8g/dL or a Hct 21-24%
When Hgb is less than 7 g/dL
the resting cardiac output increases to maintain normal O2 delivery ➔ myocardial strain.
what is hgb limit for elderly/ those with cardiac/pulmonary disease
Generally, 9 - 10 g/dL is limit for elderly and those with existing cardiac/pulmonary disease
soaked 4x4 contains approx
10 mL blood
soaked lap sponge contains
approx 100 mL of blood
what else to assess for blood loss
the suction canister
amount of irrigation used
blood lost in surgical drapes, floor, on the team’s garments
fluid replacement ratio with crystalloids
blood loss 3:1
fluid replacement ratio with colloids
blood loss 1:1
Morbidity & mortality rates – generally not affected until
the Hgb drops below 7 g/dL – where the resting CO ↑ significantly to maintain normal O2 delivery
Factors that affect O2 delivery
Inability to increase CO
Shifts to the oxyhemoglobin curve
Inadequate oxygenation
Abnormal Hgb
In adults, ____________ is an insensitive, nonspecific indicator of hypovolemia
tachycardia
In patients on inhaled anesthetics, maintenance of adequate BP implies
adequate intravascular volume
CVP should be
6-12 mmHg
Strongly suggest adequate fluid replacement
Preservation of BP and a CVP of 6 - 12 mmHg
In procedures with large fluid losses, ____________ is more accurate at estimating BP than indirect measures
an arterial line
Variations in the a-line waveform during positive pressure ventilation may indicate
hypovolemia
premature neonate estimated blood volume (EBV)
95 mL/kg
term neonate estimated blood volume (EBV)
85 mL/kg
infants and children estimated blood volume (EBV)
80 mL/kg
adult male estimated blood volume (EBV)
75 mL/kg
adult female estimated blood volume (EBV)
65 mL/kg
allowable blood loss formula
Antibodies (anti-A, anti-B) are formed whenever
membranes lack A and/or B antigens
antigens on erythrocyte membranes
A, B, Rh
erythrocyte antibodies are capable of causing
rapid intravascular destruction of erythrocytes that contain the corresponding antigens
Red cell membranes contain at least
300 different antigenic systems
Chromosomal locus produces
3 alleles
each allele represents
an enzyme that modifies a cell surface glycoprotein, producing a different antigen
80-85% of caucasians have
the D antigen
individuals that lack the D antigen
Rh-
t/f you can’t develop antibodies against the D antigen
false
1) previous Rh+ transfusion
2) pregnancy (Rh- mom delivers Rh+ baby)
ABO blood grouping
ABO-Rh typing only 99.8% compatible
type specific; 5-15 minutes
type and screen
ABO-Rh and screen; 99.94% compatible
screen process of type and screen
indirect coombs test
detects antibodies most often a/w non-ABO hemolytic reactions
how long does type and screen take
15-45 minutes
type and cross match
ABO-Rh, screen, and crossmatch; 99.95% compatible
type and cross match takes how long
at least 45 minutes
Confirms ABO-Rh typing (in < 5 min)
Detects antibodies to other blood group systems
Detects antibodies in low titers or those that do not agglutinate easily
type and cross match
always want to use ____________ for transfusion
type and cross-matched blood
if an emergency arises can use ____________
type-specific, uncross-matched blood
last resort for transfusion in emergency
O negative
packed RBCs contain
RBC’s, WBC’s, platelets, reduced plasma
Used to restore oxygen-carrying capacity and for controlled surgical blood Loss
PRBCs
usually contain a volume btwn 250-350 mL
PRBCs
Washed PRBCs
complete removal of plasma
-neonatal transfusions
-h/o severe transfusion reaction
-immunocompromised
NS is added to PRBCs to
decrease viscosity
PRBC hematocrit is
70%
filter for PRBCs
170 micronfilter to trap clots & debris
1-unit PRBC increase:
Hgb by 1 gm/dL
Hct by 2-3%
PRBC tubing should contain 170 - 230 mm filter to
trap clots and debris (degenerated platelets, leukocytes, fibrin)
what temp should PRBCs be warmed to
37º C
Hypothermic effects and low levels of 2,3 DPG in stored blood cause
left shift of oxy Hgb dissociation curve ➔ tissue Hypoxia
Glucose solutions with PRBCs may cause
RBC hemolysis
LR contains ____________ and may induce ____________
calcium; clot formation
what is compatible with PRBCs
NS, albumin, and FFP
whole blood is what % hct
40%
Used primarily in hemorrhagic shock (massive blood Loss; >25% of EBV)
whole blood
whole blood contains
all factors (RBC’s, WBC’s, platelets, plasma, including factors V and VIII)
a unit of whole blood will raise Hct ____________ and Hgb ____________
Hct 3-4% and Hgb 1 gm/dL
platelet activity after 24 hrs of storage
less than 5%
whole blood volume
450 - 500 mL
Not economical for routine use due to blood shortages
whole blood
Increased risk of allergic transfusion reaction
whole blood
If type known, an abbreviated crossmatch can be done in
5 min to confirm ABO compatibility (type specific)
O Rh-negative
universal donor
If > 2 units of ____________ given, screen recipient’s blood for antibodies before own type given
O Rh-negative
can you give O+ to women of childbearing age
NO
If > 10 units of O-
continue giving
when can you go back to type specific blood after O- transfusion
in 3-4 months (RBC last ~ 120 days)
FFP contains
plasma proteins and clotting factors (NO PLATELETS)
Utilized in coagulation deficiencies, reversal of warfarin therapy and microvascular bleeding
FFP
1 unit of FFP will increase clotting factors by
3%
Hypernatremia could result from
massive transfusion of FFP
plt less than 50,000
thrombocytopenia
1 unit of Platelet concentrate increases platelet count by
5,000 to 10,000
The presence of ____________ poses a risk of transfusion reaction
plasma
Fraction of plasma that precipitates once FFP is thawed
cryoprecipitate
contains high concentrations of Factor VIII to treat Hemophilia A
cryoprecipitate
contains high concentrations of fibrinogen to treat Hypofibrinogenemia
cryoprecipitate
Most common with a 1% incidence
febrile reaction
febrile reaction
Increase in temperature by 1 degree C
2nd most common transfusion reaction
allergic
Pruritus, hives increase in temperature
allergic reaction
ABO incompatibility can cause
hemolytic reaction
1 in 6000 transfusions
hemolytic reaction
Fatal in 1 in 100,000
hemolytic reaction
Patient “mis-identification” is the common cause
hemolytic reaction
presumptive diagnosis for transfusion reaction
Free Hgb in urine & plasma
steps to take if a transfusion reaction is suspected:
infection risk with transfusions
complications with transfusion reactions
Storage temp for blood:
1 – 6 degrees C to slow glycolysis
Biochemical changes in stored blood
citrate (preservative)
anticoagulant
binds with ionic calcium to prevent clotting
phosphate preservative
acts as buffer
dextrose preservative
substrate used for glycolysis of RBC for energy
CPD (citrate-phosphate-dextrose) shelf life
21 days
CPDA (citrate-phosphate-dextrose-adenine) includes
adenine (adenosine) for incorporation into ATP and extra glucose to prolong storage; most common
CPDA shelf life
35 days
CPDA Hct
70-80%
Citrate intoxication is from
the addition of CPD as preservative for stored blood; can occur with rapid transfusion (>150ml/min)
how is citrate metabolized
by the liver
if rate of transfusion exceeds 1 unit of blood per minute in an adult, decreased ____________ may result
calcium
Due to accumulation of citrate-chelating serum calcium
citrate intoxication
citrate intoxication is more likely to affect
Peds
Liver Dz
Symptoms of Citrate Intoxication
Treatment of Citrate Intoxication
Calcium or magnesium
Citrate will be metabolized quickly in Kreb’s cycle so symptoms may abate before treatment needed
Supportive treatment
Blood routinely screened for
HIV 1/2
Hepatitis B and C
Hepatitis C (nonA/nonB): most symptomatic (90%)
HTLV1/2 (human T-cell lymphocytic virus)
Syphilis
most commonly transmitted virus via blood
CMV
CMV negative blood should be used for
immunocompromised like BMT or organ transplants; infants;
TRALI
non-cardiogenic pulmonary edema a/w blood product administration
when does TRALI occur most frequently
with RBCs, FFP, and platelets
TRALI incidence
1 in 5000 units transfused
TRALI mortality rate
5 to 8%
TRALI’s clinical appearance is similar to ____
ARDS
(adult respiratory distress syndrome)
TRALI symptoms usually begin
within 6 hours after the transfusion
TRALI symptoms
dyspnea
cyanosis
chills
fever
hypoTN
noncardiogenic pulmonary edema
TRALI CXR reveals
bilateral infiltrates
severe ____________ can develop from TRALI
pulmonary insufficiency
TRALI treatment
largely supportive
what should happen to the transfusion during TRALI
should be stopped
TRALI vent support
low tidal volume to prevent barotrauma
Seen with massive transfusions > 1 EBV (or >10 units)
dilutional coagulopathy
dilutional coagulopathy symptoms
Treatment for Dilutional Coagulopathy
Alternatives to Traditional Blood Transfusion Therapy
