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Jasmeet K aur Fluids and Transfusion SpR in Anaesthesia, RNOH Blood Transfusion Topics Why? When? Who? Risks Massive Haemmorrhage Example 1 A fit patient with a compound fracture of the tibia and a post operative Hb of 7.5 g/dl should be transfused? Example 2
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JasmeetKaur Fluids and Transfusion SpR in Anaesthesia, RNOH
Topics • Why? • When? • Who? • Risks • Massive Haemmorrhage
Example 1 • A fit patient with a compound fracture of the tibia and a post operative Hb of 7.5 g/dl should be transfused?
Example 2 • A 70yr old woman with a history of angina and a pre-op Hb of 7.5 g/dl should be transfused?
Why? • The body at rest uses approx 250ml O2/L blood • O2 delivery can fall with a reduction in any of: • Cardiac Output • Hb concentration • O2 saturation • Organs most sensitive to hypoxia are Heart and Brain
Why? • The purpose of a red cell transfusion is to improve the oxygen carrying capacity of the blood. • Oxygen delivery to tissues (O2 Flux) = Cardiac Output x Oxygen content of blood Hb x Sa02
When? • Consider the context: • Cause and severity of anaemia • Patients ability to compensate for anaemia ( cardiorespiratory disease) • Rate of ongoing blood loss • Likliehood of further blood loss • Balance of risks vs benefits of transfusion
Transfusion Triggers • RBC transfusion not indicated when Hb>10g/dl • Hb < 7g/dl- strong indication for transfusion • RBC Transfusion less clear when Hb between 7-10 g/dl • Cardiopulmonary reserve needs to be assessed. • Symptomatic patients should be transfused. (fatigue, dizziness, shortness of breath, new or worsening angina)
Example 1 • A fit patient with a compound fracture of the tibia and a post operative Hb of 7.5 g/dl should be transfused? • T • F
Example 1 • A fit patient with a compound fracture of the tibia and a post operative Hb of 7.5 g/dl should be transfused? • T • F ✔
Example 2 • A 70yr old woman with a history of angina and a pre-op Hb of 7.5 g/dl should be transfused? • T • F
Example 2 • A 70yr old woman with a history of angina and a pre-op Hb of 7.5 g/dl should be transfused? • T ✔ • F
Summary • Think before you transfuse! • Does your patient really need blood? • Weigh up the benefits vs risks of transfusion.
Massive Transfusion Definitions • Replacement of one blood volume in a 24 hour period • Transfusion of >10 units RCC in 24 hours • Transfusion of 4 or more RCC within 1 hour when ongoing need is foreseeable • Replacement of >50% of the total blood volume within 3 hours
Massive Transfusion • Settings • Trauma • Obstetric • Surgical • “Medical”
The Perfect Clot! • Red blood Cells • Platelets • Clotting factors • Fibrinogen
The Massively Bleeding Patient… • Restore Circulating Volume: • X 2 14G IV cannulae • Resuscitate with warmed crystalloid/colloid • Warm patient • Consider invasive monitoring: arterial line + central venous access
Get some Help…. • Contact Key Personnel • Senior anaesthetist/ surgeon/ obstetrician • Blood Bank • Haematologist • Get someone to coordinate to communicate and document
Request Lab investigations • Ensure correct sample identity • FBC, ABG • Full coagulation screen • X- match • Repeat after products/4hourly • May need to give blood products before results are available
Request PRC • Uncrossmatched Group O Rh neg • Uncrossmatched ABO group specific • Fully X match • Use a blood warmer/ rapid infusion device • Consider cell salvage
Request Platelets • Allow for delivery time. • Anticipate plt count<50 x109/l after x2 blood vol replacement • Target plt count>100 x109/l for multiple/CNS trauma, > 50 in other situations
Request FFP • Aim for PT/ APTT < 1.5 x control • Allow for thawing time
Request Cryopreciptate • Contains fibrinogen and factor VIII • Aim for fibrinogen >1g/L
Summary • Recognise the situation early! • Get some help. • Aggressive management of hypothermia/acidosis • Avoid haemodilution and use appropriate volumes of blood components • Inadequately treated coagulopathy is associated with worse outcome
IV Fluids Other IV Fluids
Normal Adult Fluid Composition 60% composed of water 70 kg person= 42 L 2/3 ICF = 28L 1/3 ECF = 14L TBW= ECF + ICF
Daily Requirements • Maintenance Fluid formula • 4 ml/kg/h for the first 10 kg • 2 ml/kg/h for the next 10 kg • 1 ml/kg/h for every kg over 20 kg • Therefore a 70 kg patient using the calculation: • 40+20+50=110 • will require 110 ml/h
Daily Requirements • The normal electrolyte requirements are: • Na+ 1-2 mmol/kg/24 h • K+ 0.5-1 mmol/kg/24 h.
Fluid therapy Maintenance Resuscitation
Pre-operatively Should consider: • History, examination • Deficit (measured + insensible) • Intravascular vs cellular dehydration • Electrolyte levels • Speed of fluid loss (days/hours/minutes) • Vasodilated / ill patients may need several litres of fluid before surgery
Intra-operatively • Should use CO monitor for emergency or major surgery • Serial 200ml colloid boluses • Ongoing Hartmann’s soln with colloid • Warm fluid to reduce hypothermia
Post- operatively • Fluids are used to continue fluid replacement: • To provide daily water and electrolyte requirements, until the patient is able to drink an adequate daily volume.
Elective, well patient • Q: Fit , young pt having elective surgery not involving the abdomen what fluid losses do you expect before and during surgery of less than an hour?
Starved 6 hrs • 220ml- 660ml • Intra op losses • (minimal blood loss, loss dependent on duration) • Surgery< 1hr, loss< 150ml
Does this patient need intra op Fluid? • Not necessarily • But if hot weather, insensible losses may increase, pt may feel better post op if 500ml given
Emergency Laparotomy Pt • Q: Patient needing urgent laparotomy, history of vomiting for several days. • What fluid loss do you expect this patient to have had before surgery?
Pt may be severely water and electrolyte depleted • Large volumes fluid may be needed to resuscitate this patient • Vomiting leads to loss of hydrogen and chloride ions, NaCl solution will help to replace these • K ions may be lost in bowel, so may need replacing • Check serum electrolytes before and after fluid resuscitation
What? • Crystalloids • Colloids
Colloids • Contain Proteins/large molecules suspended in a carrier solution • Large molecules stay in the plasma, keeping infused fluid in largely in circulation. • Smaller volumes needed • Small risk of anaphylaxis
Crystalloids • Contain water and dissolved electrolytes • Pass freely through a semipermeable membrane • Many are isotonic with extracellular fluid • Need larger volumes • Cheap