Lecture 7 - Alternatives to Transfusion Flashcards
what risks to white blood cells cause in the blood?
risk of infection, inflammation and immunosuppression
how can red blood cells cause risk to patient?
may tax the body’s monocytes and macrophages and the overload may trigger inflammation and immunosuppression by altering oxygen, iron and haemoglobin
how can platelets cause risk to patient?
Microparticles derived from platelets can suppress or activate immune cells
what effect can bioactive lipids have?
polyunsaturated fatty acids can accumulate in blood units during storage and may play a role in inflammation and transfusion related immunosuppression
what is autologous blood transfusion?
collection and rein fusion of the patients own blood cells
why was predeposit autologous donations brought about?
due to concerns about viral transmission in donor blood, especially during HIV epidemic
why might a PAD be useful?
if someone does not want foreign blood, if unique blood is hard to obtain
what is acute normovolemic haemodilution?
removal of whole blood from a patient and replacement of coruscating blood volume with colloid and or crystalloid solutions
when are acute normovolemic haemodilutions performed?
immediately prior to surgery
what are the advantages of ANH?
minimise red cell loss
what are the clinical implications of ANH?
adult patients undergoing surgery in which high blood loss expected, in patients who refuse transfusion
what are the contradictions of ANH?
anaemia, renal failure, significant heart disease
what is intraoperative cell salvage?
collection and reinfusion of blood spilled during surgery
how does inoperative cell salvage work?
blood lost in surgical field is aspirated into collection reservoir after filtration to remove debris, then anticoagulated
what is blood anti coagulated with?
heparin or citrate
what are the issues of IOC?
can cause dilution of clotting factors and thrombocytopenia if used in large volumes
what is postoperative cell salvage?
blood collected from wounds drains and filtered and washed in automated system and then returned
when is postoperative cell salvage used?
in orthopaedic procedures, especially after knee or hip replacement or correction of scoliosis
what are the antifibronolytic and procoagulant drugs?
tranexamic acid, recombinant activated factor VII, fibrinogen concentrate
what is tranexamic acid?
inhibits fibrinolysis (breakdown of blood clots) by reducing the conversion of plasminogen to plasmin
what are the uses of tranexamic acid?
reduces need for transfusion and need for further surgery due to re-bleeding
what are the advantaged of tranexamic acid?
oral or IV, low cost
what is the mechanism of action of recombinant activated factor VIII?
directly activates blood clot formation at sites of exposed tissue factor in damaged blood vessels
in what patients is recombinant activated factor VIII used?
patients with haemophilia A or B or those with haemorrhages
what are the main off label uses of recombinant activated factor VIII?
cardiac surgery, trauma, intracranial haemorrhage and liver or abdominal surgery
what are the disadvantages of recombinant activated factor VIII?
extremely expensive, acidosis decreases effectiveness as adequate levels of fibrinogen are needed for clot formation
what is the purpose of fibrinogen concentrate?
replaces lost fibrinogen by serving as a physiological substrate of thrombin (which converts soluble fibrinogen to insoluble fibrinogen)
what is the mechanism of action of fibrinogen concentrate?
under the influence of factor XIIIa, fibrin strands cross-linked to provide strength and stability to the blood clots
what are the disadvantages of fibrinogen concentrate?
expensive, can cause anaphylactic reactions and thrombotic events
what are is EPO?
produced in the kidneys and increases red cell production in the bone marrow in response to reduced oxygen delivery
what are the indications of EPO stimulating agents?
anaemia or renal failure, reducing need to transfusion in cancer patients undergoing chemotherapy
what are the advantages of EPO stimulating agents?
increases yield for PAD, reducing exposure to donor blood in adults undergoing major surgery
what are the disadvantages of EPO stimulating agents?
higher hematocrits may cause thromboembolic complications and expense
what are the complications with oral iron therapy?
GI effects and compliance is poor
what are the indications of IV iron?
iron deficiency anaemia yet intolerance of oral iron or inflammatory bowel disease, as an alternative to transfusion when an urgent need for Hb (e.g. severe anaemia in late pregnancy)
what is an example of an IV iron?
ferrinject
