ch 21

Question 1

acids and bases

Answer 1

acids are H+ donors

base is a proton acceptor

Question 2

BE

Answer 2

base excess less than 0 is metabolic acidosis
value greater than 0 is metabolic alkalosis

used in clinical practice to determine lactic acidosis and determine adequacy of intravascular volume resusciation

Question 3

pka

Answer 3

the strength of an acid

Question 4

bilateral carotid endarterectomies…

Answer 4

abolish the peripheral chemoreceptor response and these patients have no hypoxic ventilatory drive.

Question 5

peripheral chemoreceptors

Answer 5

located at the carotid arteries and surrounding the aortic arch. carotid bodies are principle and are sensitive to changes in pa02, pac02, ph and arterial perfusion pressure. most sensitive to pa02

Question 6

central chemoreceptors

Answer 6

in the medulla and respond to changes in cerebrospinal fluid ph. co2 goes up -chemoreceptors are activated- and alveolar ventilation increases. this works except for very very high or very very low pac02

Question 7

renal response compensation during acidosis

Answer 7

1. reabsorption of the filtered HC03
2. excretion of titratable acids
3. formation of ammonia.

Question 8

sampling delay

Answer 8

can lead to oxygen consumption and carbon dioxide generation by the metabolically active white blood cells.

Question 9

oxygenation

Answer 9

p02 decreases 6% for every 1C degree

p02 increases 6% for every 1C degree

Question 10

rapid c02 increase

Answer 10

myocardial dysfunction then metabolic acidosis leading to confusion and loss of consciousness. due to the abrupt decrease in ph.

chronic increases are well tolerated

Question 11

causes of respiratory alkalosis

Answer 11

increased minute ventilation (tvxbpm)
hypoxia- high altitude low fi02 severe anemia
iatrogenic (mechanical ventilation)
anxiety and pain
cos disease (tumor infection trauma)
fever, sepsis
drugs (salicylate, progesterone, doxapram)
liver disease
pregnancy
restrictive lung disease
pulmonary embolism

Question 12

causes of respiratory acidosis

Answer 12

increased c02 production
    malignant hyperthermia
    hyperthyroidism
    sepsis
    overfeeding
decreased co2 elimination
    pna, ards, fibrosis, edema
    laryngospasm, foreign body, ova
    lower airway obstruction asthma and cold
    chest wall restriction-obesity scoliosis, burns
     cns depression- anesthetics opioids cis legions
    decreased skeletal muscle strength
increase co2 rebreathing or absorption
    exhausted soda lima
    incompetent one way valve in breathing circuit
    laparoscopic surgery

Question 13

anion gap

Answer 13

(CL+hc03) - Na

normal gap is 8-12

Question 14

three main regulatory molecules control coagulation and facilitate the termination of the coagulation cascade

Answer 14

antithrombin
tissue factor pathway inhibitor
activated protein C

Question 15

patient with less than what percent or what value are more likely to have uncontrolled intraoperative bleeding

Answer 15

20-30% or less than 50,000

Question 16

hemophilia A & B

Answer 16

most common recessive inherited deficiencies.
A is deficiency in factor VIII
B is deficiency in factor IX
Prolonged PTT, normal platelet count and pt

Question 17

hemophilia C or rosenthal disease

Answer 17

autosomal recessive disorder that can be associated with bleeding and is characterized by a prolonged ptt

thorough preoperative evaluation plus consult with hematologist is necessary to manage preoperative care.

Question 18

factor XII deficiency

Answer 18

a prolonged putt and is associated with clotting rather than bleeding .

Question 19

Factor XIII

Answer 19

stabilizing the fibrin clot, delayed bleeding after hemostasis, impaired wound healing, and pregnancy loss

Question 20

von willebrand disease

Answer 20

most common inherited bleeding disorder. 1% of the general population. multiple binding sites for both platelet receptors and sub endothelial structures.

ddavp- treatment of choice for type 1.
DDAVP contraindicated in type 2b
ddavp- type 3 do not respond to this treatment- they need factor VIII and vWF concentrates

Question 21

vitamin K deficiency

Answer 21

fat soluble vitamin that is required for carboxylation of factors II, VII, IX, and X and proteins C&S.
(leafy greens)
patients with poor dietary intake, TPN, ileus or obstruction, newborns, oral antibiotic therapy are susceptible to vitamin k deficiency

Question 22

liver disease

Answer 22

clotting factors (except factor VIII are synthesized in the liver.

Question 23

what should not be used with hemophilia B

Answer 23

cryoprecipitate

Question 24

protein c protein s

Answer 24

protein c can be acquired secondary to underlying disease. seen with liver disease, severe infection, septic shock, and dic.
protein s associated with pregnancy, oral contraceptives, dic hiv, nephrotic syndrome and liver disease.

Question 25

DIC

Answer 25

caused most commonly from sepsis widespread systemic activation of coagulation. leads to end organ dysfunction and multi organ failure. consumption of of circulating coagulation factors platelets and fibrinogen results in life threatening bleeding. thrombocytopenia elevated fibrin degradation products (d dimer) prolonged pt and ptt low fibrinogen

Question 26

TXA-

Answer 26

in patients with active bleeding and suspected fibrinolysis antifibrolinitcs are administered.

Question 27

ACT

Answer 27

used for heparin monitoring in CABG patients. ACT must be greater than 400 to start bypass.

Question 28

plavix

Answer 28

noncompetitive irreversible antagonist. increased variability among population. ticagrelor has much lower inter individual variability.

Question 29

warfarin

Answer 29

disrupts the formation of factor II, VII, IX and X and proteins C&S 40hr half life. early reductions in the anticoagulant protein c causes hyper coagulable state.

Question 30

heparin

Answer 30

main complication of heparin is HIT. mortality rate of HIT is 30-40% suspect if platelets fall less than 100,000 or less than 50% baseline 5-10 days after initiation of heparin ...if patient previously hit positive for cabg, titers to heparin should be preformed if timing allows.

Question 31

low molecular weight heparin

Answer 31

inhibit factor Xa do not affect the ptt assess by factor Xa levels longer half lives- give one or twice daily protamine is only partially effective in reversing lmwh protamine not effective for fondaparinux lmwh contraindicated for HIT+

Question 32

bivalirudin (angiomax)

Answer 32

shortest half life and is the drug of choice for renal and hepatic dysfunction. (argatroban (a DTI) will prolong the inr the most which can complicate transition to warfarin)

Question 33

ventilatory response vs renal response

Answer 33

ventilatory response occurs in minutes renal response can slowly provide nearly complete restoration of the pH but it can take days.

Question 34

bicarbonate buffer system

Answer 34

co2 combines with water- makes carbonic acid- hydrogen and bicarb.