Quiz 10 Flashcards
Do platelets have a nucleus?
no- they cannot reproduce
What does a TEG measure?
process of clot formation over time
What are the physiologic effects of a pneumoperitoneum?
bradycardia (can pretreat with glyco), CO2 absorption, decreased ventilatory ability
What is factor 4?
calcium
Platelets are mostly inactive until?
vessel injury
What receptors are on platelets?
GPIIb-IIIa, thrombin, TxA2, ADP, and GPIb
Where are platelets formed? What is the normal value and what is their normal lifespan?
megakaryocytes in bone marrow; 150-300k, 8-12 days
What is on the external membrane of platelets? What do they do?
glycoproteins- repelled by healthy endothelium, adheres to injured endothelium, collagen and fibrinogen
phospholipids- substrate for prostaglandin synthesis (produces thromboxane A2 which activates platelets)
What does the severity of thalessemia depend on ?
number of gene deletions
What is normal fibrinogen levels?
150-350 mg/dL
What is factor 13?
fibrin stabilizing factor
What does thrombin time measure? What is normal?
fibrinogen-to-fibrin reaction (8-12 seconds)
What is factor 2?
prothrombin
What does D dimer measure? What is normal?
degradation products secondary to fibrinolysis- <500 mg/ml
When is the extrinsic pathway activated?
when coagulation is initiated outside intravascular space
What are the 4 steps of hemostasis?
1) vascular spasm
2) formation of platelet plug (primary hemostasis)
3) coagulation and formation of fibrin (secondary hemostasis)
4) fibrinolysis when the clot is no longer needed
What is factor 1?
fibrinogen
What is factor 12?
Hageman factor
What are some complications that may occur during the establishment of a pneumoperitoneum?
vascular injury (venous bleeding might show up late due to tamponade from pneumoperitoneum), gas embolism, visceral injury, pneumo, subQ emphysema
If somebody just has sickle cell trait, when might sickling occur in terms of PaO2?
<20 mmHg
Why should you be conservative with your fluids if the patient is in Trendelenberg?
excess fluid can cause facial and airway edema, may increase IOP (blindness)
What is factor 5?
labile factor
Why is CO2 the gas used for laparascopic surgery?
inexpensive, does not support combustion, readily absorbed from the vascular system, and readily excreted by the pulmonary system
What do you give Dani if she ever comes in as a trauma?
platelets
At what platelet level do patients have a surgical risk? what about spontaneous bleeding?
<50k surgical risk, <20k spontaneous bleeding
When is the intrinsic pathway activated?
when coagulation is initiated inside intravascular space