Trauma/transfer Flashcards
Advantages of Bier’s block?
Avoidance of GA
Bloodless field
Relatively cheap and easy (no sonoanatomy skills)
Rapid recovery
Disadvantages of Bier’s block?
Limited to procedures <60m
No post op analgesia
Potential risks include: LAST, nerve injury from pneumatic cuff, compartment sx, skin discolouration
Contraindication to IV RA (Bier’s)
Absolute
- Raynaud’s
- Berguer’s disease
- AV fistula
- LA toxicity
- Pt refusal
Relative
- High systolic bp (as cuff may not go that high)
- Children (intraosseus vasculature bypasses)
- Local infection
- Crush injury
- Lymphoedema
- Morbid obesity
- Sickle cell
- Uncooperative patient
Tell me about prilocaine
Amide LA
Max dose 6mg/kg
Wide therapeutic index
Longer duration of action than lidocaine, shorter than bupivicaine
Methaemaglobinaemia may result from prilocaine metabolite O-toluidine
How to perform a Bier’s block
Preparation
- Preop assessment and consent
- AAGBI standard monitoring
- Trained assistant
- IV access (both hands)
- Intralipid available
- ‘STOP, PREP, BLOCK’
Process
- Exsanguinate limb
- Double cuff, check both working, then inflate proximal
- Inject LA
- After 10mins inflate distal and deflate proximal
- Motor and sensory block around 10-15mins
- Max time for cuff inflation 45mins
CNS features of local anaesthetic toxicity
Initial excitatory phase
- Perioral tingling
- Tinnitus
- Slurred speech
- Seizures
Depressive phase
- Resp depression
- Coma
CVS features of local anaesthetic toxicity
Initial phase
- Tachycardia + hypertension
Intermediate phase
- Myocardial depression + hypotension
Terminal phase
- Severe hypotension + arrythmias
How would you manage L.A toxicity
Phase 1:
This is an emergency
Stop injecting
I would call for help
Scan the patient and monitors
Alert surgeons if operating
Phase 4: CRM
1. My priorities are general supportive strategies specific to the clinical features
2. Instigating specific treatment for LA toxicity in form of intralipid
I would want additional resources to support these priorities and would request cognitive aids to ensure correct following of steps and doses
- ABCDE approach maintaining airway, instituting 100% oxygen, giving fluids/vasopressors
If Arrythmia - ALS
If C. arrest - ALS
If Seizures - benzos or thiopentone - Intralipid 20%
1.5ml/kg bolus, 15ml/kg/hr infusion
Up to 2x further boluses can be given and infusion rate doubled
What is parkland formula for fluids
First 24hrs = 4ml/kg x TBSA burn
Give half in 8hrs
Rest in 16hrs
Principles of crit care mx. of burns
Invasive monitoring
- Art and central line
Nutrition
- Early enteral to prevent gut translocation;
- High requirements due to higher BMR
Micro
- Meticulous asepsis and monitoring for infection
- Burns often become colonised
- Special dressings and dressing changes
Fluid mx
- Guide by urine output, CVC etc
Mechanical ventilation
- Lung protective
- Aggressive pulmonary toilet/BALs needed
- Big ETT (uncut)
What % TBSA burn needs to go to burn centre
> 3% adults
2% children
Complications of burn injury
Early and Late
Early:
1. Complications from fluid over-administration
- Burn oedema
- Pulmonary oedema
- Abdominal compartment syndrome
2. Infective
- Burn wounds
- Catheter associated
- VAP
- Line related
3. DVT
4. Gastric ulcer
5. AKI
6. Hypothermia
Late:
Pulmonary fibrosis
Chronic pain
Sleep disorder
Mental health disorder
- PTSD
- Depression
Signs and symptoms of inhalational burn injury
Voice change/hoarseness/cough
Stridor
Burns to lips, tongue, mouth, pharynx
Soot in sputum
Resp distress
Hypoxaemia
Increased CO levels
Mx of CO poisoning
High flow O2
Ventilation with FiO2 1.0
Hyperbaric O2 but not indicated after smoke inahalation injury
Mx of cyanide poisoning
Hydroxycobalamin 5g over 15mins
Mx of inhalational burn injury
Bronchoscopy dx and grading and washout
Lung protective ventilation - limit TV to 6mls/kg, apply PEEP, permissive hypercapnia
Nebulised heparin, 20% NAC, salbutamol
Chest physio
Changes with altitude that affect transfers
Expansion of air filled spaces
- Pneumothoraces
- ETT cuff, measure frequently
Decreased FiO2 therefore consider intubation/ventilation beforehand
Ambient temperature decreases
Classes of haemorrhagic shock
Class 1 - blood loss 750mls
Class 2 - blood loss 750-1500mls
Class 3 - blood loss 1500-2000mls
Class 4 - blood loss >2000mls (>40% blood volume)
What are the 3 components of damage control resuscitation
Permissive hypotension
- Tolerating lower MAPS/systolic to prevent dislodgement of clot
- Controversial especially in TBI
Early haemostatic resucitation
- Resuscitate with FFP:platelets in addition to blood
- E.g. pack A
Damage control surgery
- Limited interventions aimed at haemorrhage control and minimising contamination
- Definitive surgery takes place when patient physiologically normalised
What trials show the benefit of TXA in major trauma
Crash 2
- Large multicentre RCT
- TXA given as 1g bolus and infusion 1g over 8hrs
- Reduced death in bleeding trauma patients compared with placebo
- No statistical increase in DVT/PE
Crash 3
- Large multicentre RCT
- TXA reduced deaths in patients with mild to moderate TBI compared with placebo
- No statistical increase in DVT/PE
Best given EARLY but definitely within 3 hrs
What are the clinical effects of the following currents
1mA
3-9mA
>8mA
>15mA
>25mA
>50mA
1mA = threshold for feeling
3-9mA = pain without tetany
>8mA = burns
>15mA = tonic muscle contraction - unable to let go
>25mA = tonic contraction of resp muscles - resp arrest
>50mA = ventricular fibrilation
What is microshock
An otherwise imperceivable electric current applied directly or in very close proximity to the heart muscle
Of sufficient strength, frequency and duration to cause disruption of normal cardiac function
Current 10microA = absolute safety limit for cardiac connections
Current 100microA = likely to cause microelectrocution (VF)
What is drowning
Defined as respiratory impairment due to being submersed or immersed in liquid
Why might acute lung injury arise from drowning
- Atelectasis
- Direct toxic effect - hypotonic fresh water results in interstitial oedema
- Osmotic gradient of saltwater favours fluid shift into alveolus
- Bronchospasm
- Negative pressure pulmonary oedema and alveolar rupture
- Direct toxic effect of chlorine/pollutants
- Infective complications
