Bits and Bobs (mainly stolen from anki) (thanks Joe) Flashcards
What is the target ICP
<22 mmHg
In bleeding, what endogenous processes have a procoagulant effect
endothelium activation which leads to
a) platelet activation and adhesion
b) subendothelial tissue is exposed which has procoagulant effects
c) clotting factor production and release
In bleeding, what endogenous processes have a anticoagulant effect
a) aPc activation: reduced factor 5 and 8 + increased plasmin
b) platelet dysfunction
c) glycocalyx barrier is shed
d) increased fibrinolysis due to release of tPA, PAP and proteolytic enzymes eg plasmin
What is the definition of ROSC
aortic BP maintained >60 for 10 consecutive minutes
Describe primary, secondary, tertiary and quarternary blast injuries
primary: blast wave itself causing hollow organ damage
secondary: debris injuries
tertiary: injuries from being thrown from the blast
quarternary: injuries as a result of the explosion such as burns
What is the oxygen extraction equation
oxygen extraction = oxygen removed from blood by metabolising tissue/oxygen delivery
as oxygen delivery reduces what happens to oxygen extraction and why
it increases to compensate for the reduced delivery in an attempt to maintain the amount available for tissues to use
what would a high oxygen extraction indicate
reduced delivery
increased usage
what would a low oxygen extraction indicate
increased delivery (hyperbaric chamber) decreased usage
what is the downside of permissive hypotension in TBI
further reduces CPP inducing secondary ischaemic injury
Why do we use permissive hypotension
lower hydrostatic pressure so less likely to disturb any clots that have formed
reduced acidosis, hypothermia and haemodilution
What prothrombin time indicates ATC and what should be given to correct it
> 18 seconds
What INR indicates haemorrhagic complications
> 1.5
Why do we want to avoid pain in bleeding patients
pain further increases sympathetic activation which in turn leads to:
glycocalyx barrier disruption
vasoconstriction so worsening tissue hypoxia
What is a downside of ROTEM machines
Don’t take into account any exogenous anticoagulants
State some complications of transfusions
acute haemolytic transfusion reaction (ABO incompatibility)
TRALI
sepsis
TACO
Reference ranges for platelets
140-400 x 10^9/L
Reference ranges for Hb and haematocrit
Hb: 115-180 g/L
haematocrit: 0.4-0.54
Normal PT and APTT
PT: 10-14 seconds
APTT: 24-37 seconds
Reference ranges for fibrinogen
1.5-4.5 g/L
What is the advantage of being acidotic in bleeding and what are the disadvantages
reduced affinity of Hb for O2 so offloads
however…
increased work of breathing to compensate
reduced catecholamine receptor responsiveness
reduced clotting factor activation
increased fibrinolysis
TXA complications and contraindications
seizures and hypotension
pregnancy, renal failure and seizure history
In which DCS patients should interventional radiology be considered
active arterial pelvic haemorrhage
spleen, liver, kidney injury with arterial haemorrhage
define base excess
The amount of acid needed to return 1L of fluid to a normal pH
What 4 key processes contribute to ATC
glycocalyx barrier shedding: autoheparinization and fibrinolysis
platelet dysfunction: activated on mass but then become exhausted and don’t respond to further stimulation
depleted fibrinogen: used up
aPC: resulting in anticoagulation and fibrinolysis
define base excess
The amount of acid needed to return 1L of blood to a normal pH
What 3 processes/ reflexes are involved in the physiological response to blood loss
arterial baroreceptors: reduce vagal tone and increase sympathetics
cardiac vagal c fibres: induce bradycardia and vasodilate in an attempt to reduce myocardial O2 demand
arterial chemoreceptors: tachypnoea and vasoconstriction
Describe the benefits of filming within pre-hospital care
educate the public
increased funding
benefit of telling your story for the patients
highlight safety issues
Describe the negatives of filming within pre-hospital care
consent and confidentiality issues
distracts the clinicians
can give false hope if only happy stories are shown
The storage of RBCs reduces what components of it?
2-3DPG
neutrophils
haematocrit
State the 4 stages of DCS
0=hameorrhage control and recognition that a patient needs DCS
1=initial exploratory laparotomy
2=physiological correction in ICU
3=further definitive surgery
The storage of RBCs reduces what components of it?
2-3DPG (increased affinity of Hb for O2)
neutrophils
haematocrit
What is fibrin glue
fibrinogen + thrombin
produces a clot in 10 seconds
What blood products to HEMS carry
blood-plas (mixed o negative and plasma)
PCC
TXA
What are the NICE guidelines for permissive hypotension
aim for palpable central pulse (femoral or carotid)
Describe the MOA of TXA
binds to lysine receptors on plasminogen and prevents the conversion to plasmin therefore reducing the amount of plasmin available to break down the fibrin clot
What is the role of factor 13
fibrin stabilisation: converts soluble fibrin to insoluble fibrin by crosslinking
It is activated by thrombin
What are the LAA RSI indications
unconscious airway obstruction at risk of ventilatory failure humanitarian to facilitate procedures ie predicted clinical course severe agitation
What is the role of factor 5
bound to activated platelets it is needed by factor 10a to convert prothrombin to thrombin
What dose of Ketamine would you use for analgesia, sedation IV and sedation IM
analgesia: 0.1mg/kg
IV sedation: 0.5mg/kg (slightly more in paeds)
IM sedation: 5mg/kg
What are the LAA RSI indications
unconsciousness airway compromise ventilatory failure humanitarian to facilitate procedures severe agitation
What is oxygen delivery dependant on
CO
Hb O2 saturation
Hb concentration
Compare when you’d use CT, FAST and DPL for assessment of a trauma patient
stable? = CT
unstable and FAST no available = DPL
complications of a thoracotomy
pneumothorax phrenic nerve damage vagus nerve damage bronchopleural fistula arrhythmias
complications of a thoracostomy
intercostal artery damage and bleeding recurrent pneumothorax blocked drain diaphragm injury re-expansion oedema
benefits of doing a subclavian CVC over IJV
can do it with a cervical collar in place
can do it during chest compressions
more likely to be successful in bleeding as held open by surrounding structures
complications of CVC
pneumothorax
brachial plexus injury
lymphatic duct damage
phrenic nerve damage
REBOA complications
femoral artery damage = retroperitoneal bleed aortic rupture (balloon overinflation) ischaemic distal to balloon hypertension and worsening TBI thrombosis
How is DPL carried out
can be open or closed
1) incision is made between pubic symphysis and umbilicus
2) aspirate
3) if no blood then flush with 1L of fluid
4) drain and send for analysis
What does DPL assess
intraperitoneal haemorrhage
hollow organ damage
Complications of DPL
bladder or stomach injury if not been deflated
iliac vessel damage
compare the advantages and disadvantages of DPL, FAST and CT
DPL and FAST >CT : be done if patient is unstable, no radiation damage, cheaper
FAST > DPL: reproducible, non-invasive, no interference with any subsequent CT scans
CT> FAST and DPL: assess solid organ damage, assess retroperitoneum
How do you calculate the weight of a child
(age + 4) x 2
How do you calculate ET tube size for a child
(age/4) + 4
How much fluid do you give to a paediatric patient as a bolus
20ml/kg
What energy is used to shock a paediatric patient
4j/kg
What is the dose of lorazepam and adrenaline for a child
lorazepam: 0.1mg/kg
adrenaline: 0.1ml/kg 1:10,000
What is the dose of dextrose for a child
2ml/kg of 10% dex
How is TCA managed
simultaneously: manage catastrophic haemorrhage gain control of the airway and ventilate bilateral chest decompression Then assess if thoracotomy is appropriate for relief of cardiac tamponade and proximal haemorrhage control via aortic compression activate MTP
When should a death be reported to the coroner
occurred within 24 hours of admission
occurred whilst under anaesthesia
unnatural or suspicious
died of industrial disease
Target MAP and CPP in TBI
MAP 90mmHg
CPP 70mmHg
signs of a retroperitoneal bleed on a plain film
obliteration of psoas outline
Where do the vertebral arteries travel
transverse foramen
State some issues with a permissive hypotension strategy
differing definitions used by different people
Can worsen TBI
Doesn’t work if the hypotension is caused by a bleeding mimic
Individuals require differing blood pressures (eg a hypertensive 100kg man would need different to a 90y/o 50kg female)
based largely on animal studies
Which clotting pathway is measured by PT and which by APTT
PT: extrinsive
APTT: intrinsic
What does hypothermia do to the oxygen dissociation curve
shifts it left meaning Hb has a higher affinity for O2
Pathological endogenous processes occurring as a result of TBI
catecholamine surge leading to:
a) glycocalyx shedding leading to coagulopathy
b) coronary vasospasm and myocardial ischaemia
c) neurogenic pulmonary oedema
BBB breakdown leading to inflammatory factor release into systemic circulation
consumptive coagulopathy due to platelet activation factor and brain tissue factor release
Benefits of cryo over FFP
less volume so lower risk of TRALI and TACO
less need for blood type matching
TARN stands for what
trauma audit and research network
Problems caused by intubating a haemorrhage patient
induction agents cause further hypotension
PPV reduces diastolic filling
Signs of a pneumothorax on eFAST
absence of lung sliding and B lines
presence of A lines and lung point sign
