IV Fluids and Bloods Flashcards
What are clinical signs of dehydration?
Dry mucous membranes
Loss of skin turgor
What are the following indicators for fluid resuscitation?
SBP
Pulse
Capillary Refill Time
Respiratory Rate
NEWS Score
JVP
Urine Output
Acid-base levels
Serum U&Es
Serum Osmolality
SBP <100 mmHg
Pulse >90
Capillary refill time >2 secs +/- cold peripheries
Respiratory rate >20 breaths
News 5+
JVP - raised if fluid overload
Urine output - decreased if dehydrated
Acid-base - disturbances occur in extremes of fluid states
Serum U&Es - will be raised in dehydration
Serum osmolality - will be increased in dehydration
How is passive leg raising used in terms of fluids?
If BP improves when legs are raised rather than legs down, it suggests fluid responsiveness.
What are the routine maintenance average requirements of a normal patient?
25-30ml/kg/day water
1 mmol/kg/day K, Na & Cl
50-100g /day glucose
How much water should be prescribed to a patient who more vulnerable (e.g. older, frailer, renal impairment, cardiac failure, malnourished or at risk of refeeding)?
20-25 ml/kg/day
Most patients don’t require more than how many litres per 24 hours?
Most patients do not require more than 3L fluid in 24 hours
What is refeeding syndrome?
Starvation - then food reintroduced - have low serum K, Mg and P as the cells pump these ions intracellularly along with glucose. Can cause pulmonary and neuro symptoms and can be fatal.
When a patient has severe oedema, how much of the fluid that you give a P will be lost to the interstitial area?
1/3 at least
Of fluids given to a sceptic patient, how much fluid will be lost into the EC space?
1/3 at least
Hypo and hypernatremia - how do these affect fluid levels?
Hyponatremia - means that the water will move intracellularly
Hypernatremia - the water will stay extracellularly in the intravascular space
For resuscitation - what volume of fluid should be given to patients in a bolus?
How should this be altered if they are older or have heart failure?
500ml over 15 mins
If older / CHF - this should be reduced to 250ml
When should you seek help with a patient in terms of amount of fluid given in a bolus?
When you have given 2L to a patient OR 1L if they are older Ps
What are the contents of 0.9% saline?
Sodium and Chloride
154 mmol/L Na
154 mmol/L Cl
308 Osmolarity
What are the contents of 5% glucose?
Water and sugar
277 mmol/L glucose
Osmolarity 278
What are the contents of Hartmann’s?
Na, K, Cl, Ca, HCO3
Na - 131 mmol/L
K - 5 mmol/L
Cl - 111 mmol/L
Ca - <0.5 mmol/L
What are the benefits and negatives of 0.9% saline solution?
Similar osmolarity to plasma - doesn’t rupture or dehydrate RBCs
Very salty - can cause. significant acid base abnormalities
What are the benefits of 5% glucose?
Glucose is metabolised to H20 and CO2 - so therefore you give the P pure water.
Which solution is the closest physiologically to blood?
Hartmann’s
What alternatives can be used to blood transfusion?
Erythropoietin (takes time)
IV & Oral Iron
Tranexamic acid
What is tranexamic acid used for?
To reduce interoperate bleeding and therefore reduce transfusion requirements
What are the rates of transfusion for the following?
Red blood cells
Platelets
FFP
Cryoprecipitate
RBCs - 1-2 hours - no slower than 4 hours
Platelets - 30-60mins
FFP - 10-20ml/kg/hour
Cryoprecipitate - quickly - 15-30 mins at a time
What is the difference between FFP and Cryoprecipitate
Both are made from plasma however cryo has more concentrated clotting factors in it such as Von Willebrand Factor, Factor 8 and fibrinogen
Which are the clinical S&S of a transfusion reaction?
Fever, chills or rigors
Hyper or hypotension
Collapse
Flushing
Urticaria
Pain (bone, muscle, chest, abdomen)
Nausea
Respiratory distress
General malaise
What are the 3 grades of transfusion reaction?
Mild, moderate or severe
What is the easiest way to differentiate the transfusion reaction severity?
Pulse - minimal or no change = mild
Inc of 10 bpm+ = moderate
Inc of 20 bpm+ = severe
What should you do if you suspect a transfusion reaction?
Stop the transfusion. Measure obs.
Check identity of patient, their bracelet and the label of the bag and the tag attached to the bag.
Mild reaction - stop transfusion but leave connected - continue at reduced rate for 30 mins and observe. If ok then resume at prescribed rate.
Moderate reaction - stop and leave connected. Urgent clinical review, check identity of patient and bag. If symptoms improve in 15 mins - restart with antihistamines or antipyretics.
Severe reaction - stop and disconnect - recheck details - inform transfusion lab & complete appropriate documentation.
What is the mechanisms of action of Aspirin?
Irreversible COX1 inhibitor
This stops thromboxane A2 being produced - and therefore reduces the attraction of other platelets and reduces them sticking together.
Less adhesion, activation and aggregation.
Which chemical is produced by normal endothelium that has an inhibitory effect on platelet activation by having an opposite effect to thromboxane?
Prostacyclin (PGI2)
Why do we not use aspirin at high dose for anticoagulation?
At high doses aspirin will inhibit production of both thromboxane and prostacyclin. At lower doses it will selectively inhibit platelets (but not endothelial cells which produce prostacyclin) - so will have the desired effect.
What dose of aspirin is considered a low dose?
75-325 mg/day
ADP is released by platelets when they are activated. How is it considered an agonist of platelets?
ADP binds to P2Y12 receptor on other platelets - increasing the aggregation, activation and adhesion of them.
What is the mechanism of action of clopidogrel?
Clopidogrel is a P2Y12 receptor inhibitor
Which drug is first line for peripheral arterial disease?
Clopidogrel
Apart from clopidogrel - which other drugs target the P2Y12 receptor?
Ticagrelor
Prasugrel
More reliable and potent - however greater bleeding risk than clopidogrel
Which MOA anti-thrombotic drugs are the most powerful and carry the highest bleeding risk?
Glycoprotein 2b3a receptor antagonists - stops the platelets being bound together with fibrinogen.
E.g. Tirofiban
Abciximab
Which factors does warfarin inhibit?
1972 was the diSCo era
10, 9, 7, 2 and Protein C & S
What is the lag period for warfarin?
3-4 days
Warfarin has a narrow therapeutic window which is monitored by INR (the extrinsic clotting pathway). What INR should Ps aim for?
2-3
What does Warfarin interact with?
Alcohol
Green vegetables
Main drugs - esp Abx
What does INR measure?
The ratio of the patient’s PT to a normal PT.
Prothrombin time (PT) is a blood test that measures the time it takes for the liquid portion (plasma) of your blood to clot.
When is warfarin used?
Mechanical heart valves
Mitral stenosis with AF
What are the side effects of warfarin?
Bleeding
Teratogenic
Skin necrosis
What do you need to do when you start a patient on warfarin?
Also start them on transient heparin at the same time as Ps are in a hypercoagulable state in warfarin induction.
How does heparin work?
Enhances the affect of anti-thrombin which inhibits factors 2, 7, 9, 10, 11 & 12. Heparin binds to AT and activates it.
What is unfractionated heparin used for?
CKD
Dialysis
What is heparin monitored with?
APTTr
Activated partial thromboplastin time (APTT) of the patient
How is unfractionated heparin given?
IV or subcut
Measured in units (not mg)
Name 2 LMWHs
Enoxaparin
Tinzaparin
What are LMWHs used for?
How are they cleared?
MI, AF, PE, iliofemoral DVT, VTE prophylaxis.
Cleared renally
What is the dangerous side effect of heparin?
HIT
Heparin-induced thrombocytopenia
What is the mode of action of Rivaroxaban and Apixaban?
Direct Factor Xa inhibition - therefore stops prothrombin being converted to thrombin which stops fibrinogen being converted to fibrin.
What is the mode of action of Dabigatran?
Direct Factor IIa (Thrombin) inhibitor - stops conversion of fibrinogen to fibrin
What are DOACs used for?
DVT
PE
AF
Post knee / hip replacement
How do DOACs compare to Warfarin?
Which drug can reduce thrombus breakdown and how?
Tranexamic acid
Is a anti-fibrinolytic - so stops plasmin breaking down fibrin.
What can vitamin K be used to treat?
Vitamin K deficiency
Reverse warfarin effects in OD.
Which thrombolytic agents can be used to break down thrombi by converting plasminogen to plasmin?
TPA (Tissue Plasminogen Activator)
Alteplase
Used for acute MI, recent thrombotic stroke, major PE or massive iliofemoral thrombosis
What is the difference between antiplatelet drugs and anticoagulants?
Antiplatelets - stop platelets clumping together to form a clot
Anticoagulants - slow down the body’s process of making clots.
What are the two types of antithrombotic drugs?
Antiplatelet drugs
Anticoagulants
How do we treat bleeding in a patient who is on anti-thrombotic?
Stop the drug
Check renal & hepatic function
Baseline coagulation and platelets
Correct any problems - fluids / RBC transfusion
Apply mechanical pressure if needed
Can think about radiological intervention of bleeding source if needed.
How can you reverse vitamin K antagonists - e.g. warfarin?
Give Vitamin K
Oral or IV 1-10mg
Takes 4-6 hours to work
If urgent need to reverse - can give a prothrombin complex concentrate - e.g. Beriplex, Octaplex - is concentrated Vit K dependent factors. Has effect in 10-30mins but short half life.
How can you reverse heparins?
Stop heparin
UFH - half life is 45-90 mins
LMWH - half life is 4 hours
Can give protamine sulphate - rapidly reverses UFH and partially reverses LMWH (60%)
What is the reversal agent for Apixaban or Rivaroxaban?
Andexanet α - is a recombinant form of FXa
What is the reversal agent for Dabigatran?
Idarucizumab
What other things can you give to a patient who is bleeding with a DOAC?
PCC or FFP
Tranexamic acid
How can you reverse anti-platelet drugs?
