Anaesthesia IV Week 1-6 Flashcards
What is a hypotonic solution?
The ECF has less solute and less osmotic pressure than what’s in the cells therefore water moves into the cell to attempt to balance solute concentrations.
The cell gets lysed (burst)
What is a hypertonic solution?
The solution has more solute and higher osmotic pressure than what’s in the cell therefore water moves out of the cell to dilute the solute.
The cell shrivels and crenates
What is an isotonic solution?
The fluid has the same concentration of solute and osmotic pressure as within the cell
What are the sodium and water requirements per day?
100-150 mmol Na
2-3 L water
(Usually 2500ml in and 2500ml out)
What is a crystalloid?
An aqueous solution of mineral salt or other water soluble molecules
A solution which mimics plasma
Contains electrolytes and small particles
What is a colloid solution?
Large insoluble molecules which cannot cross the membrane - exerts osmotic pressure causing fluid to remain in this space
Suspended in a solution
Increase the circulating volume
Longer effect than crystalloids - slower to break down
What is a problem with dextrose 5% solution?
The dextrose gets metabolised quickly leaving water (solution) in the ECF which is hypotonic. Therefore water moves into the cells and dilutes electrolytes (hyponatraemia)
What is the fluid replacement scheme?
40ml/kg/24hr
For replacement fluids
This can be increased by 15% for every 1 degree Celsius over normal temperature
What is the paediatric fluid replacement guideline?
The 4-2-1 regime
4ml/kg/Hr for each of the first 10kg
2ml/kg/Hr for each of the second 10kg
1ml/kg/Hr for each subsequent 1kg
Fluid: 0.45% NaCl/5% dextrose
Why are lactated ringers contraindicated when infusing blood?
Contains calcium.
Blood has an additive in it which prevents the RBCs from clotting by binding to the calcium. By adding calcium from the Hartmans solution, clots are able to form.
Why is it ok to give calcium during MTP?
Because most of the calcium in the blood is bound and the levels in the body are becoming low. By giving calcium, the heart becomes more efficient at contracting.
What fluids are contraindicated with blood products?
5% dextrose may induce haemolysis
Lactated ringers and gelofusine may induce clotting
Define haemolysis.
The destruction of RBCs
What is the fluid to blood ratio of the fluid groups?
Crystalloid: 3:1
It travels throughout the ECF whereas colloids have large insoluble molecules which encourages them to stay in the plasma compartment
Colloid: 1:1
What are the fluid compartments?
Total 60% (45L) fluid in body (75% child)
Intracelluar: 2/3 (28L) of the water (40%)
Extracellular: 1/3 (14L) of the water (20%)
- interstitial: 11L (3/4) of ECF
- plasma: 3L (1/4) of ECF
+/- colloids
Replace blood 1:1 Expands circulating volume High cost Can affect coagulation Large molecules don't cross membrane At high volumes the affects may reverse Anaphylaxis risk
+/- crystalloids
Replace blood 3:1 No allergy risk Water soluble molecules Electrolytes Mimics the plasma Low cost
What are the hazards of rapid infusion?
Air embolism Drug error Accidental bolus from fluid refluxing Tissue toxicity (incorrect IV) Phlebitis Anaphylaxis Temperature high or low Fluid overload Fluid contaminations Mechanical faults in lines Arterial injection
Describe the components of blood.
RBC: 45%
Plasma: 55%
Buffy coat (WBC, platelet) 1%
What is plasma?
The liquid part of the blood which contains antibodies and proteins
What are red blood cells?
Enucleated cells which contain haemoglobin capable of transporting oxygen throughout the body.
Last for 120 days
Also called erythrocytes
What is third spacing?
When too much fluid moves from the intravascular space to a transcellular space (a space somewhere in the body it shouldn’t be eg bowel lumen) where it cannot participate in fluid movement
What are normal blood volumes?
Normal blood volume is 70ml/kg (5L adult) and 80ml/kg child
What is the total body water?
60% men
50% women
75% child
TBW= 0.6 X weight (for a man)
Therefore 45L of water for a 70Kg man
What is extra cellular fluid?
All fluid outside the cells
What is interstitial fluid?
The fluid which surrounds the cells
What is transcellular fluid?
A part of the ECF and is contained in epithelial lined spaces
What is osmosis?
Diffusion of water across a semi permeable membrane from an area of low solute concentration to an area of high solute concentration
What is a fluid challenge?
100-200ml bolus of fluid
A sustained rise is CVP >3mmhg suggests the patient is well filled.
If not sustained rise, keep bolusing
What is hypernatraemia and the treatment?
High serum sodium
Treat with 5% dextrose (hypotonic)
What happens in untreated hypovalaemia?
Low perfusion Low oxygenation Organ damage Organ failure Death
What are colloids made of?
Albumin - protein
Dextran - polysaccharide (can affect cross match and clotting)
Gelatines - collagen
Starches - maize
What is a syringe pump?
Programmable Set infusion rate and bolus Maintain a constant infusion Mechanism: pulsatile continuous delivery 2.5% accurate Battery and mains Need Anti syphon valves prevent free flow Correctly engage syringe Shouldn't be >100cm above patient
What’s a burette?
A accurate fluid delivery device placed between bag and giving set
1ml divisions
High accuracy for volume infused
Ball valve prevents air entry
What are the protocol around blood infusing equipment?
Approved devices only Sterile sets 170-200 micron pore filter Prime with normal saline or product Change set every 4 units or 10 units in MTP or 8 hourly Need new set for platelets Don't add drugs to this line Warm if large/rapid volumes Keep below 41 degrees
Name 4 isotonic solutions.
Normal saline
Hartmans
Gelofusine
Volulyte
(Also plasmalyte, dextrose 5%)
Name 3 hypertonic solutions.
Saline 3%
Dextrose 10%
Mannitol
Name 3 hypotonic solutions.
- 45% saline
- 5% dextrose
- 18% saline
What is an acute haemolytic reaction?
Incompatible red cells react with patients antibodies
Can cause DIC and renal failure
Fever, rash, hypotension or sudden spike, oozing wounds, Hb in plasma or urine, difficult breathing, agitation
What is a bacterial contamination reaction?
Can be from IV site, skin plug, donor, processing contamination.
Signs of infection and sepsis
More likely in warmer products eg platelets
To reduce: check product bag and expiry, donor testing, disinfect donor skin, discard initial 10ml sample, monitor platelets with detection system
What is a DHTR?
Delayed haemolytic transfusion reaction
A haemolytic reaction >24hours after infusion
Secondary immune response
Commonly Jk or Rh
What is a NHFTR?
Non-haemolytic febrile transfusion reaction
Fever or rigors during transfusion
Slow/stop rate; give antipyretic
Can be mild to moderate
Washed cellular products may be better for these patients
What is a TRALI?
Transfusion related acute lung injury
When donor plasma has antibodies against patients leukocytes
Respiratory distress, hypoxaemia, pulmonary oedema, cyanosis, tachy, fever
Female donor with multiple children commonly have the antibodies (HLA, HNA)
What is a TACO?
Transfusion associated circulatory overload
Infusion too rapid or too much volume
Respiratory distress, tachy, high BP, distended neck veins
Treat with diuretic, O2, compress lower limbs, sit up
What reactions can occur with a blood transfusion?
Acute haemolytic Bacterial contamination DHTR NHFTR Allergy/anaphylaxis TRALI TACO Graft-vs-host disease (donor lymphocytes attack) Immunosuppression Post transfusion purpura (low platelets cause haemorrhage)
What biochemical reactions may occur from blood transfusions?
Hypocalcaemia from citrate binding to Ca
Hyperkalaemia (high potassium during storage)
Acid-base disturbances
Describe ABO blood typing.
A, B, AB, O
Determined by antigens on cell surface (agglulinogens)
Plasma contains antibodies to any antigens not present on cells
(Agglutinins)
What are the blood universals?
Donor: O- because it has no surface antigens to attack
Recipient: AB because these people have no antibodies to attack other blood groups
Why is recipient blood most important when blood matching?
Consider a patient who is AB blood group therefore have no antibodies. So we could give them a unit of A (which in theory would have B antibodies) because it is just RBC ie there isn’t plasma (which carries antibodies). A bag of RBC has a small amount of plasma that passes through but not enough to harm the patient.
CONSIDER DONOR ANTIGEN BUT RECIPIENT ANYIBODY
Describe the Rhesus factor.
Present +
Carries on RBC surface
Not spontaneously formed antibodies: Rh + never forms, Rh - may form antibodies from exposure
First exposure sensitises and second exposure causes reaction
Why is Rh a problem on pregnancy?
When there is a Rh- mother with a Rh+ child
First pregnancy is ok but mother gets sensitised at birth and produces Rh antibodies
During second pregnancy the mothers antibodies will attack the child
Mothers antiD crosses placenta and agglutinates babies RBC - death or brain damage
How is Rh problems treated?
Inject mother with anti D agglutinins to agglutinate Rh factor so mother can’t become sensitised
Inject at 28 weeks and after birth
What is the compatibility of the products?
RBC: must match
Platelet or cryoprecipitate: ideally the same but can differ
FFP: must match but remember it’s inverse to normal chart
What should be considered when giving O-?
Can use to start an emergency
Take G+H as soon as possible
Preferred no more than 4 units
Remember it’s precious and does contain some A and B antibodies!!!
What are the conditions of donation?
At an approved centre 16-60 y/o In good health >50Kg Complete paperwork Informed consent Test for ABO, antibodies and disease Leukodeplete (filter out WBC to reduce infection and affects) Labelled correctly
What is apheresis?
Process where a particular substance is removed and the rest is returned to the donor eg plasma
How must a sample be collected?
Check patient ID
Informed consent
Hand write blood tube
Collect and complete entire process in presence of patient with no interruption
How long are samples valid for?
Pt transfused/pregnant/Hx antibodies: 72 hours
None of above, in hospital: 7 days
None of above, pre admit clinic: 21 days
What is autologous donation?
Patient donates own blood prior to surgery
Includes:
pre operative collection - weeks before
Peril prestige acute haemodilution - immediately prior
Cell salvage
High cost, stringent planning, risk getting it wrong, weakens the patient, high waste, no haemolytic risk, bacterial risk remains
Describe pre operative autologous collection.
Patient donates a unit per week in the month before surgery.
Reduced transfusion risk
Bacterial risk remain
May need Fe supplement
Circulatory overload possible with whole blood
Describe perioperative acute haemodilution donation.
Patient donates whole blood immediately before surgery - replace volume with fluids - then return blood at the end providing clotting factors etc
Unstable patient
Less cost and less error risk
Storage correct in theatre
Describe cell salvage.
Hooked up to surgical suction; or from drains
Can replace close to what is lost
Endless
Debra risk - DIC
Need skilled staff
Cell destruction occurs
Can’t use with OBS - reinfuse fetal contaminants, not for bacterial contaminated sites, malignant disease
What is a directed donation?
A certain person is sought after and donates for a specific person
Doesn’t use bank supply, available quickly
Transfusion risks remain, increased GVHD of family, donor may not disclose, high cost, major planning
What are surgical techniques to reduce blood loss?
Radiology help Diathermy Laparoscopic LA with adrenaline Pre- surgical optimise eg iron Tourniquet
What are anaesthetic techniques to reduce blood loss?
Keep a lower BP Keep patient warm Position eg head up Drugs - maintain clotting Haemodilution - reduce RBC loss
What is a volumetric pump?
(Alaris) Programmable Specific giving set Ideal for accuracy of total volume NOT precise flow 5-10% accuracy Various mechanisms Battery/mains
Define massive transfusion.
One blood volume in 24 hrs
50% in 3 hrs
> 150ml/min
What is TURP syndrome?
Hyponatraemia
Watch height, volume and time of glycerine solution given. This is absorbed out of the blood leaving hypotonic water therefore sodium is diluted and some leaves the cell to balance.
Confusion, N+V, fitting, ^RR, headache
High HR and high BP
What is the make up of the nervous system?
Central nervous system communicates with the peripheral nervous system which can be split into two: sensory which gathers information from sensory organs and motor which sends out signals to organs. Motor can be divided into somatic (voluntary) control of skeletal muscle and autonomic which controls glands, cardiac and smooth muscle. Autonomic can further divide to sympathetic and parasympathetic
Describe a somatic fibre
One ganglion
Acetylcholine at the junction
Describe the sympathetic fibre
Thoracolumbar
Pre ganglion: T1 - L2, short, acetylcholine
Post ganglion: long, nor adrenaline
Describe the parasympathetic fibre.
Craniosacral
Pre ganglion: cranial nerves (3, 7, 9,10) and S2-S4, long, acetylcholine nicotinic
Post ganglion: short, acetylcholine muscarinic
Define agonist
A chemical that binds to a receptor and triggers a biological response
Full: produce full efficacy
Partial: produce mild efficacy
Inverse: produce negative efficacy (bind to receptor but induce opposite response to agonist)
Define antagonist
A chemical that binds to a receptor and blocks it preventing other chemicals from binding
Competitive: (reversible) will compete with agonists for the site eg naloxone
Non-competitive: (irreversible) binds to different site than agonist and prevents activation eg ketamine
Define bioavailability.
A subcategory of absorption and is the amount (%) of an administered drug that reaches the systemic circulation unchanged. IV is 100%.
Affected by first pass metabolism, solubility and chemical stability
Define clearance
A pharmacokinetic measurement of the volume of plasma from which a substance is completely removed per unit of time (ml/min). Excreted via urine, sweat, saliva, expiration.
Define context sensitive half time
The time taken for the blood plasma concentration of drug to decline by one half after an infusion designed to maintain steady state has been stopped
Define half life
The time required for the concentration of a drug in the plasma to be reduced by one-half. This depends on how quickly the drug is eliminated
Define pharmacodynamics
The physiological and biochemical effects a drug had on the body and its mechanism of action
Define pharmacokinetics
The movement of drugs within the body including the processes of absorption (entering circulation), distribution (dispersing through fluid and tissue), metabolism (becoming metabolite) and excretion (removal).
Define receptor
A protein molecule on a cell surface or inside a cell which has a high affinity for a specific chemical group or molecule which can bind and trigger a response. Can be ion channels, G-proteins (activate second messenger) or enzyme linked.
Define tachyphylaxis
A rapid decrease in the response to a repeated dose over a short period of time
Define tolerance
A persons diminished response to a drug when it is continually used and the body adapts to its presence.
Define volume of distribution
The theoretical volume (L) needed to contain the total amount of a drug at the same concentration that is observed in the plasma. This represents the spread within the body. A large number (42) indicates good spread into the tissues. Vd= dose/plasma conc.
Define drug
A chemical that affects physiological function in a specific way
Define metabolism
Mainly liver - process of chemically changing drug to metabolite
Phase 1: chemical reaction changes to metabolites (oxidation, reduction, hydrolysis)
Phase 2: conjugation to inactive compounds by attaching ionised groups. Changes drug/metabolite into soluble compound for excretion by increasing its polarity (glucuronidation, suphonidation)
Define first pass metabolism
Drug absorbed from agai tract and passes through the liver via the hepatic portal before entering the systemic circulation. Results in a very small amount reaching circulation
Describe the nicotinic receptor
Acetylcholine Found in all pathways Ion channel which is opened by acetylcholine binding Brief and fast response All excitatory
Describe the muscarinic receptor.
Acetylcholine Parasympathetic pathway only G protein coupled - when Ach binds it changes its shape and activates a secondary messenger Slow and prolonged Can be both excitatory and inhibitory
Describe adrenergic receptor
Noradrenaline Sympathetic pathway only G protein coupled A1: vasoC smooth muscle A2: inhibit NA B1: cardiac contractility and HR B2: lung bronchodilator
Describe propofol
10mg/ml 2-3mg/kg induction 0.5mg/kg bolus sedation Soya bean oil and egg protein Short acting; quick onset Sedative/hypnotic GABA agonist Injection pain, myoclonic spasm (caution epilepsy), hypotension, reduced PONV
Describe thiopentone
3-5mg/kg Fast onset, short acting Doesn't cross placenta Barbiturate/hypnotic Accumulation with repeat doses Anticonvulsant, cerebral protection, hypotension, high PONV, injection pain
Describe midazolam
0.5-5mg titration Sedative/amnesiac/anxiolytic/anticonvulsant 20-60min duration Reversal by flumezanil GABA agonist PO, IV, IM
Describe ketamine
Dissociative anaesthetic/analgesic NMDAR antagonist; opioid agonist Good for shock and trauma Bronchodilator, ^ICP, ^BP, ^salivation, respiratory depression, delirium IV, IM
Describe etomidate
0.3mg/kg Hypnotic CVs stability Fast onset, short acting Pain on injection, PONV, myoclonic movements, adrenocorticol suppression
What are the competitive (non-depolarising) relaxants?
Short- mivacurium
Medium- rocuronium, atracurium, vecuronium
Long- pancuronium
Describe rocuronium
0.6-1mg/kg intubation Non-depol/comp 2-40min action Ach Nic antagonist antagonised by acetylcholinesterase Tachycardia
Describe atracurium
Benzylisoquinolinium, non-depol/comp 90s - 35min Ach Nic antagonist Low anaphylaxis risk, histamine release Hoffman elimination: temp and pH dependant so spares renal and hepatic
Describe mivacurium
Short acting Non-depol/comp 16min duration Metabolised by plasma cholinesterase so risk of long block Antagonised by neostigmine
Describe suxamethonium
50mg/ml
1-1.5mg/kg (1-2paeds)
Non competitive/depolarising
Rapid onset and short acting
Similar to 2x Ach molecules
Bind to Ach Nic first opening then blocking
Fasiculations from first activating the receptor = repetitive firing
Metabolised by plasma cholinesterase risk of long block
Can cause low calcium, MH, high IOP, ICP, bradycardia with second dose, muscle pain, high potassium
Don’t use in burns, head injury, eye injury, spine injury, MH, crush injury, cholinesterase deficiency
Put the common analgesics in order of increasing potency
Pethidine Morphine Alfentanyl Fentanyl Remifentanyl
Describe opioid receptors
Inhibitory G-protein coupled receptors with opioids acting as agonists. These slow the transmission of pain signals and also encourage release of chemicals such as dopamine
Delta Kappa Mu Nociceptin Zetta
Describe morphine
Mu and kappa agonist
PO, IV, PCA, IM, SC, epidural, spinal
Why is ITM an advantage?
Close to effect site, less respiratory depression, small dose and dose times, less side effects, stays at the site, long duration
Describe fentanyl
30-60min duration
CVS stable
IV: 1-5mcg/kg
Epidural: 50-100mcg
Spinal: 5-10mcg
Describe remifentanyl
Short acting 5-10min
Supplement anaesthetic
Describe alfentanyl
10min duration
5-10mcg/kg
Describe tramadol
Drug of threes: opiate receptor agonist, increase serotonin, reduce reputable or noradrenaline
Caution in epilepsy
50-100mg 4 hourly
Describe parecoxib
NSAID, cox-2 inhibitor
Inhibits enzyme causing pain and inflammation
40mg then 20-40mg 6-12hourly
Describe paracetamol
Analgesic,antipyretic
Caution in neonate, liver damage - toxic metabolite can build up and cause failure. This is treatable with N-acetylcysteine which is a precursor to glutathione, the antioxidant of the liver that the paracetamol metabolite damages.
Load dose 30mg/kg then 15mg/kg max60mg/kg/day
What are common adverse effects of opioids?
Respiratory depression Reduced GI mobility N+V Constipation Addiction Sedation Pruritis Tolerance Hallucinations Dry mouth
What are common adverse effects of NSAIDS?
GI upset Ulceration Asthma trigger Reduced platelet aggregation Renal impairment ^MI risk
Describe clonidine
Selective A2 agonist
Sympathetic pathway: A2 receptor is prejunctional and prevents release of NA
Reduced opioid requirement, sedative, reduce blood pressure
Acts centrally at brain stem and reduces sympathetic outflow
150-300mcg
Describe ondansetron
Serotonin (5HT3) antagonist - preventing it binding and triggering the N+V centre
Antiemetic
4mg Qds
Describe dexamethasone
Corticosteroid, antiemetic, reduce oedema
2-8mg
What are considered high PONV risks?
Female Motion sickness Non-smoker Opioids GI, gynae, craniotomy, strabismus, otolaryngology
What is step up opioid therapy?
1: non-opioid
2: mild opioid
3: strong opioid
4: RA
Remember a multimodal approach is best
What is the antiemetic combination therapy?
Mild risk: 1 drug
Moderate: droperidol OR Dexamethasone with a serotonin antagonist
High risk: combination therapy
Describe neostigmine
Anti cholinesterase Reversal of non-depol relaxants Acts at the Ach junction by inhibiting acetylcholinesterase from breaking down Ach therefore more available to compete. Some receptors must be available in order to work. Also increase flow along parasympathetic causing bradycardia. 50-70mcg/kg with atropine or glyco Glycopyrolate matches timing better
Describe atropine
Anti muscarinic/anticholinergic
Ach muscarinic receptor antagonist
Increase HR, reduce secretions, confusion
10mcg/kg IV
Describe adrenaline
A+B adrenergic agonist
Can prolong LA
Causes vasoC, contractility and ^HR
High BP, high HR, anxiety, arrhythmia, reduced uterine blood flow
Describe ephedrine
A+B adrenergic receptor agonist
Increase contractility, vasoC and HR
Safe in pregnancy, tachyphylaxis
Describe phenylephrine
Alpha adrenergic agonist
Peripheral vasoconstriction
Describe metoprolol
Beta adrenergic antagonist
Reduce contractility and HR
Describe labetalol
A+B adrenergic antagonist
Reduce vasoC, contractility and HR
Describe esmolol
Beta adrenergic antagonist
Reduce contractility and HR
Describe salbutamol
Beta2 agonist
Bronchodilator
High doses also bind to B1 causing high HR/tremor
Describe sevoflurane
Halogenated ether
Potentiate GABA, glycine and two-pore domain K channels
Reduce TV, increase RR, reduces MAP, prolong QT, increase PONV
Removed by lungs
Risk MH, compound A, carbon monoxide
What is special about the adrenal medulla?
In the adrenal gland
Contains chromaffin cells which excrete adrenaline, NA and dopamine.
Considered post ganglion neutron of SNS and received info via pre ganglion neuron directly from CNS
Quick signal!
Chemicals excreted directly into blood stream
What is the second gas effect?
Increase in the pp of other gases in the alveolar due to rapid uptake of N2O
Induction and emergence
N2O is highly soluble so taken up quickly - the reduction of volume of N2O in alveolar (due to rapid uptake to blood) then increases concentration of agent available to go into the blood
Describe amiodarone
anti-arrhythmic
Treats SVT and V arrhythmia
Acts on nodes to increase the gap via sodium and potassium channels
300mg slow IV bolus for adult defib
Describe carboprost
Prostaglandin
Treat PPH after ergometrine and oxytocin fail
Never give IV - deep IM or direct myometrium
Describe dantrolene
Direct acting skeletal muscle relaxant
Treatment of MH
Reconstitute in 60ml water and put through giving set
Crosses placenta, muscle weakness, phlebitis
Describe ergometrine
Control uterine bleeding
Don’t give IV - IM with oxytocin
Describe oxytocin
Hormone
Stimulates uterine contraction and increases tone, milk release
Induce labour and treat PPH
Slow IV 5U or 40U 125ml/Hr
How to calculate the number of Mg in a drug?
%conc X volume X 10
Describe bupivicaine
With glucose
Slower than lignocaine
200-400 minutes
High cardio toxicity so not for IVRA
Max 2mg/kg/4hr
Describe lignocaine
Rapid onset
30-90 minutes
Also treats V arrhythmia and reduces pressor effect from intubation
Max 3mg/kg/4hr (6mg with adrenaline)
Describe ropivicaine
200-400min
Less cardio toxic
Max 3-4mg/kg/4hr
Describe prilocaine
Lowest toxicity; toxicity reduced with methylene blue
Good for IVRA
Rapid onset
30-90 min
Max 6mg/kg/4hr (8mg with adrenaline)
How do the local anaesthetics work?
Sodium channel blockers
Prevent sodium channels opening therefore sodium cannot enter and depolarise the cell
What is EMLA?
Eutectic mixture of local anaesthetic
2.5% lig and 2.5% pri cream
Describe sodium citrate
Alkaline solution
Neutralises stomach acid immediately
Describe ranitidine
H2 receptor antagonist
Stops stomach acid production
Describe tranexamic acid
Inhibit plasminogen activation (plasminogen dissolves fibrin)
Not for pregnant or renal impaired
Describe intralipid
20% emulsion
Soya oil (fatty acids)
Draws local out of plasma where it binds to it or the lipid counteracts the LA inhibition of myocardial fatty acid metabolism therefore preserving ATP in the heart
What needs to be considered in renal and hepatic impairment?
Reduced metabolism and clearance
Prolonged duration and build up of metabolites
Initial dose may be the same but subsequent dose intervals will be longer and dose sizes reduced to maintain peak concentration and avoid toxicity
Avoid some - NSAIDs
Swap some - sux for atracurium
Describe sugammedex
Selective relaxant binding agent
Binds to rocuronium and vecuronium
16mg/kg
Describe excretion
Mainly in the kidney (also sweat, saliva, milk, lung, intestine)
Glomerular filtration
Active tubular secretion and some passive reabsorption
Secretion from peri tubular capillaries to the nephron and reabsorption from nephron back to capillaries.
Water and electrolytes
Polar compounds cannot reabsorb
Secretion important for drugs
What are some sources of ECF?
CSF Lymph Synovial fluid Pleural fluid Aqueous humour
Describe GABA
Gamma aminobutyric acid
Inhibitory NT
Reduced excitability of cells
Both ion and G-protein function
What is Hoffman elimination?
Spontaneous degradation of a drug at normal body temperature and pH
What is DIC?
Disseminated intravascular coagulation
Widespread activation of the clotting cascade causes clots to form in small vessels leading to multiple organ damage. Consumption of coagulation factors then leads to severe bleeding.
Diagnosed via lab tests
Some causes: MTP, PPH, sepsis, blood cancer, transfusion reaction
What is the volume, storage, time requirements and use of Cryoprecipitate?
100ml -25 degrees 2 years Must be thawed for use (2-6 degrees) 4 hours after thawed Use in 4 hours Return In 30 minutes Fibrinogen, von Willebrand, factor VIII and factor XIII
What is the volume, storage, time requirements and use of FFP?
280ml -25 degrees 2 years Must be thawed for use (2-6 degrees) 24 hours after thawing Use within 4 hour Return within 30 minutes Coagulation factors and proteins >4 RBC
What is the volume, storage, time requirements and use of platelet?
300ml 20-24 degrees, agitated 7 days Use within 1 hour Return within 1 hour Clotting >4 RBC
What is the volume, storage, time requirements and use of RBC?
300ml 2-6 degrees 35 days Use within 4 hours Return within 30 minutes Increase tissue oxygenation Hb less than 70
What is aminophylline for?
Treats lower airway obstruction in paediatric anaphylaxis
Bronchodilator
Improves diaphragm contraction
What is irradiation and leukodepletion?
Leukodepletion removes leukocytes to reduce immune mediated response
Irradiation removes lymphocytes to reduce GVHD (lymphocytes attack the recipient)
Why thiopentone for obstetrics?
Because it is historically safer and better known than other agents
