Intra-op Fluid Management Flashcards
(55 cards)
1
Q
How do you replace fluid according to the historical school of thought?
A
- insensible fluid loss—> from urine, feces, sweat, resp.
- replace with 2mL/Kg/Hr
- 3rd spacing: depends of size of fluid shift
- minimal trauma: 3-4 ml/kg
- moderate trauma: 5-6mL/kg
- severe trauma 7-8mL/Kg
(Huge incision)
2
Q
How is fluid loss replaced according to new thought/ periop goal directed fluid therapy (PGDT)?
A
- use hemodynamic monitoring to guide fluid replacement
- dilution: CO with PAC
- pulse contour: vigileo/flow track
- echo/es. Doppler
- give 250mL bolus and monitor cardiac response to determine if pt needs fluids or meds (frank-starling curve)
- ERAS—> build them up bore, then when we knock them down they don’t have as far to climb
- minimizes fluids
3
Q
What is true regarding crystalloids?
A
- cross plasma membrane- may dilute plasma proteins
—> increased risk of pulmonary edema in large volumes - when replacing blood loss: crystalloid is 3 xs blood loss amount, in order to account for volume loss and 3rd spacing (historic)
** no glucose containing solutions—> BAD.
Usually just use isotonic
4
Q
What is true regarding colloids?
A
- use 1:1 to replace blood loss
- colloids stay in plasma
- hetastarch- not used much d/t coagulopathies (decreases factor VIII)
- dextran- decreases platelet adhesiveness, potential for anaphylaxis, interferes with blood crossmatch—>not used much
- 5% Albumin: used for rapid expansion of intravascular volume
(25% causes higher pull, mostly used in ICU)
5
Q
What are s/s blood loss?
A
- tachycardia, hypotension, decreased CVP, decreased mixed venous O2
- give pain meds, if no ∆, give IVF
- oliguria: <0.5ml/kg/hr
- SBP/respiration variation >10mmHg (pulsus paradoxes)
6
Q
A young healthy pt may lose 20% of circulating blood volume without clinical signs. Why is this?
A
Vessels can squeeze really tight, and heart can pump really hard to compensate
7
Q
What are indications for a blood transfusion?
A
- primary indication is to increase O2 carrying capacity of blood
- justified when Hg <6G/dL
- CAD with acute anemia may transfuse <10g/dL
8
Q
How is acute hemorrhage managed?
A
- when blood loss >1/3 entire blood volume —> give blood, not fluids
- if blood loss causes hypovolemic shock , give blood
- whole blood is preferred
9
Q
What is the major risk of a transfusion reaction?
A
- incompatibilities to A, B antibodies, A, B, Rh antigen cause cause rapid hemolysis.
10
Q
What is cross matching?
A
Incubating recipients plasma with donors RBCs
Takes about 45 min to complete
11
Q
Emergency transfusions use O negative PRBCs. Why?
A
- lacks a, b, Rh antigens
- will no be hemolysis by anti-a or anti-b antibodies that may be in the pts blood
12
Q
What is a risk of transfusing large amounts of O negative blood?
A
You have now changed their blood type.
—> now if you give their blood type it may react
* get type and crossed blood ASAP instead of running O -neg blood for a long time
13
Q
What is type specific blood?
A
- 1st phase of crossmatch done- only tests for a,b, Rh antigens
- chance of significant reaction is 1:1000
- used only in emergency situations
14
Q
What is a type and screen?
A
- typed for a,b,Rh antigens, plus screened for most common antibodies
- patients blood is NOT matched to donor unit-
- allows for a unit of blood to be available for more than 1 pt
- ordered for surgical procedures with remote risk of transfusion
—> cross match is done after type and screen - chance of hemolytic reaction is 1:10,000
15
Q
What preservatives are in stored blood?
A
- Phos.: buffer
- dextrose: energy to RBCs
- adenine—> to make ATP (adenine triphosphate) for metabolism-increases survival time
16
Q
How long can blood be stored for and what is the reason for this?
A
- 21-35 days
- it is required that 70% of RBCs be viable 24 hours after transfusion
17
Q
What is the volume, Hct, and citrate level of whole blood?
A
Volume = 450mL
Citrate= 65mL
** Hct= 40% **
18
Q
What components can be derived from whole blood?
A
PRBCs Platelets FFP Cryoprecipitate Albumin Plasma proteins fraction Factor VIII Leukocyte poor blood Antibody concentrates
19
Q
What is the benefit of component therapy?
A
Allows for specific deficits to be corrected and longer storage time
20
Q
What are some facts you should know when transfusing PRBCs?
A
- one unit contains:
Volume = 300mL
Hct = 70% - Hgb should increase 1G/gL per unit PRBCs in 70 kg adult
- when given with hypotonic solution, PRBC swelling and lysis
- if calcium in solution—> clotting
- only infuse with NS *
21
Q
What are some advantages of using PRBCs?
A
- decreases potential for citrate toxicity compared to whole blood
- decreases risk for allergic reaction
22
Q
When is a platelet transfusion indicated?
A
- platelets <50,000 cells/mm^3
- with trauma or bleeding into brain, eye, airway a higher threshold may be used
- platelet count should increase 5-10,000 cells/mm^3 in 70kg adult
23
Q
What are risks of platelet transfusion?
A
- viral disease transmission
- human leukocyte antigens present on platelet cell membrane
- bacterial infection in 1:12,000 transfusions
- small risk of sepsis
24
Q
What is in FFP?
A
- contains all plasma proteins
- all coagulation factors except platelets
- factor V and VIII
25
When is FFP indicated?
- Pt/Ptt > 1.5 xs normal and clinical indication of transfusion
- reversal of warfarin
- correction of known factor deficiency (von Wilderbrans)
26
What is in cryoprecipitate?
High concentrations of:
- factor VIII and XIII
- von Wildebrans
- fibrinogen and fibronectin
27
Which component has the highest amount of von Wildebrand factor?
FFP has the highest total amount
| While cryoprecipitate has the higher concentrated amount
28
When is cryoprecipitate indicated?
- factor VIII deficiency (hemophilia A)
- von Willdebrands factor deficiency
- fibrinogen deficiency
29
During MTP what is the ratio of PRBC:FFP:Platelets?
4:1:1
30
What are the 3 types of transfusion reactions?
Febrile
Allergic
Hemolytic-life threatening
31
What happens during a febrile transfusion reaction?
- antibodies react with antigens
** most frequently occurring reaction *
- s/s:
Fever
Chills
HA
Myalgias
Nausea
Productive cough
*typically not life threatening *
32
What is the treatment for a febrile transfusion reaction?
- check pt’s serum and urine for hemolysis (r/o hemolytic reaction)
- slow down the rate and give anti-pyretics
33
What is happening during an allergic transfusion reaction?
- incompatible plasma proteins in donor blood
- s/s:
Urticaria (rash on chest, seen first)
Pruritis
Occasional facial swelling
34
What is the treatment for an allergic transfusion reaction ?
- Stop transfusion
- Make sure its not a hemolytic reaction by checking urine and plasma for free Hgb
- Administer IV antihistamine (Benadryl)
35
What is a hemolytic transfusion reaction?
STOP TRANSFUSION IMMEDIATELY
- from giving erroneous blood to pt
- recipients antibodies attack donor blood
- as little as 10mL blood can result in fatal hemolytic reaction
- severity is proportional to volume transfused
* * may result in renal failure and DIC
36
What are s/s hemolytic transfusion reaction?
```
Fever
Chills
CP
Hypotension
Nausea
Flushing
Dyspnea
Hemoglobinuria (red urine)
** anesthetics mask all s/s but hypotension and hemoblobinuria
```
37
What labs results will be seen in a hemolytic transfusion reaction?
- Dx made by direct antiglobulin test
- draw: plasma and urine Hgb, billirubin
- billirubin peaks 3-6 hrs after start of transfusion
38
What is the treatment for hemolytic transfusion reaction?
* * stop transfusion **
- Prevent renal failure by giving enough fluids to maintain UOP @ 100mL/hr by running LR and giving Mannitol or lasix
- give bicarbonate to alkalize the urine and stop crystal ppt
- labs: [Hgb], baseline coags, urine
- return blood to lab with repeat crossmatch from pt
39
What types of metabolic abnormalities can occur from blood therapy?
- elevated H+ and K+—> body compensates—> become alkalotic
- decreased 2.3 DPG
- decreased Ca—> citrate binds free Ca
- all of these potentially result in a left shift—> leads to tissue hypoxia
(Typically not seen, but theoretical)
40
The pH of stored blood is 7.1-6.9 d/t increased levels of CO2 in stored blood. Why does it not make your blood acidic?
Recipient eliminates CO2 via the lungs
| Citrate metabolizes to bicarbonate upon transfusion
41
How much K+ is in a unit fo blood?
20-30mEq/L
| Usually insignificant until large volumes transfused and pt has underlying dz (renal)
42
Why is hypocalcemia observed with blood therapy and how is it treated?
- citrate binds to Ca in plasma
- worse with hypothermia, liver disease and hyperventilation
- rarely requires tx
Give 1 G Ca Cl IV or 3 G calcium gluconate
43
What are the viruses transmitted by blood therapy?
- HIV—>1:1 million
- hepatitis—> 1:60,000
- cytomegalovirus
44
What are microaggregates?
From stored whole blood —> platelets and leukocytes
- concern they will accumulate in the lungs and obstruct vasculature causing ARDS
- prevention:
- transfuse whole blood through a fine filter (10-40 nm diameter) ( standard filters are 170nm diameter, much larger)
45
What happens with hypothermia with blood therapy?
- erratic EKG, cardiac irritability
- post op shivering—> increases myocardial demand
—> run blood through a warmer
46
What are coagulation disorders with blood therapy?
- dilutional thrombocytopenia
- s/s:
Frank bleeding without clotting at surgical site
Hematuria
Spontaneous oozing from puncture sites
47
What do you need to know about DIC?
- causes:
- significant tissue damage with release of toxins
- large amount of transfused blood
LABS:
- prolonged PT and PTT
- decreased fibrinogen
- increased fibrin split products
TREATMENT:
- treat underlying cause
- give FFP and platelets
48
What is TRALI?
- occurs within 6 hours
- acute non cardiac pulmonary edema
- supportive treatment
- most spontaneously recover
49
What is immunosuppression with blood therapy related to?
- r/t volume of plasma ( whole blood > immonusupression than PRBCs)
- beneficial in transplant pts
- bad with malignancy
50
What happens with autologous blood transfusion?
- pt donates own blood weeks prior to surgery
- decreased risk of complications
- consider when significant surgical blood loss anticipated
(Still stored blood so have those risks)
51
What is itraoperative salvage?
Considered when blood loss expected from a CLEAN WOUND
- Contradinicated:
* malignancy
- blood borne diseases
- bowel content contamination
52
What is the make up of cell saver blood?
Hct= 50-60%
PH is alkaline—> CO2 hasn’t had a chance to build up yet
- only returning PRBCs
53
What are complications of intra- op salvage?
- dilutional coagulopathy
- mixed with heparin so anticoagulation can occur
- hemolysis
- air/fat embolism
- sepsis
- DIC
54
What is the hemodilution technique?
Removed pts blood the same day as surgery and store it
- transfuse after major blood loss over
- replace lost volume with IVFs
- dilutes blood loss during surgery
Contraindicated: anemia, severe cardiac or neuro. Disease
55
How is EBL replaced?
- crystalloids- 3:1
| - colloids and blood- 1:1
