Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Unit 11 PBL cases > Trauma > Flashcards

Trauma Flashcards

1
Q

What is the continuation of the artery supply the lower limb?

A

Common iliac > external iliac - femoral once passed under inguinal ligament - popliteal artery once enters posterior compartment of thigh > terminal branches: anterior and posterior tibial arteries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the branches off the femoral artery?

A

Superficial epigastric artery
Superficial circumflex iliac artery
Superficial external pundendal artery
Deep external pudendal artery
Profunda femoris
Descending genicular artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the arterial supply in the thigh and gluteal region?

A

Common iliac > external iliac > femoral
Profunda femoris artery PFA from femoral
PFA branches: perforating branches, lateral and medial femoral circumflex
Common iliac > internal iliac > obturator artery > anterior and posterior branch
Internal iliac > superior and inferior gluteal arteries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the arterial supply of the leg?

A

Popliteal artery divides into anterior tibial artery and tibioperoneal trunk
Tibioperoneal trunk bifurcates: posterior tibial and fibular artery
Anterior tibial artery runs down into the foot and becomes the dorsalis pedis artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the arterial supply of the foot?

A

Supplied via two arteries:
Dorsalis pedis > anastomoses with lateral plantar artery and forms deep plantar arch
Posterior tibial > splits into lateral and medial plantar arteries > deep plantar arch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a crush injury?

A

Compression of part of the body that causes muscle swelling/neurological disturbances

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is crush syndrome?

A

Crush injury with systematic manifestations
Systemic manifestations caused by traumatic rhabdomylolysis (destruction of skeletal muscle) due to muscle repurfusion injury when compressive forces are released
Cause local tissue injury, organ dysfunction, metabolic abnormalities - acidosis, hyperkalemia, hypocalcaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the pathophysiology of crush syndrome?

A

After prolonged compression on muscle tissue
- Ischaemia reperfusion (pressure relieved) causes traumatic rhabdomyolysis
- Muscle cell rupture releases large quantities of potassium, phosphate, myoglobin, CK, LDH and urate > enter circulation
- Excess myoglobin filtered by kidneys - precipitates in DCT causes obstruction when renal threshold is exceeded. Vasoconstriction of afferent vessels due to myoglobin metabolic products > tubular destruction
- NO system is activated and further leads to vasodilation and hypotension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is crush syndrome characterised by?

A

Hypovolemic shock - due to sequestration of water in injured muscle cells
Hyperkalaemia - due to release from injured muscle cells
Can lead to:
- Metabolic acidosis: release of cellular phosphate and sulphate by injured cells
- Acute kidney injury: from excess myoglobin filtered
- Disseminated intravascular coagulation: due to release of thromboplastin and prothrombin from muscle cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How does rhabdomyolysis cause metabolic acidosis?

A

Excessive cell breakdown releases uric acid
Hypovolemia and poor tissue perfusion can cause release of lactic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How does rhabdomyolysis cause hyperphosphatemia?

A

Leukocytes move into damaged muscle cells upon reperfusion and cause release of muscle breakdown products into bloodstream including phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How does rhabdomyolysis cause hyperkalaemia?

A

Leukocytes move into damaged muscle cells upon reperfusion and cause release of muscle breakdown products into bloodstream including potassium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How does rhabdomyolysis affect calcium?

A

Initial hypocalemia:
Muscle injury causes influx of calcium and sodium. Hyperphosphatemia causes deposition of calcium phosphate in destroyed muscle cells and other tissue.
Later hypercalemia:
Calcium leaks out of myocyte after cell lysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the clinical presentation of crush syndrome?

A

Crushing of large muscle mass
Sensory and motor disturbances in compressed limb - become tense and swollen - limb may become pulseless
Myoglobinuria and haemoglobinuria may make urine brown
Oligouria with hypovolemic shock
Nausea, vomiting, confusion, agitation
Elevated urea, creatinine, uric acid, postassium, phosphate, CK
Hypo/hypercalcemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How does rhabdomyolysis cause hypovolemic shock?

A

Muscle cell injury > influx of sodium and calcium
Water is drawn into the cell with sodium > cell swelling and disruption of membranes
Massive fluid shift from extracellular fluid and blood into cells.
Pre-shock: compensatory mechanisms - increased sympathetic tone - increased HR, cardiac contractility, peripheral vasoconstriction.
Continued volume decrease > shock state: fall in systolic BP, tachycardia, oliguria
Tissue hypoperfusion, hypoxia - switch to anaerobic respiration > lactic acidosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What blood tests should be ordered for crush syndrome?

A
  • U&Es:
  • Creatinine
  • Calcium
  • Phosphate
  • Creatinine kinase
  • Uric acid
  • FBC and clotting studies
  • LFTs
  • Blood gases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How may a patient with a crush injury be treated?

A
  • Primary survey ABC
  • IV access and fluid resuscitation prior to releasing crushed extremity
  • Short term use of tourniquet if required
  • Acute limb amputation should be avoided until extrication is impossible
  • Aggressive hydration to combat hypotension
  • Haemodialysis
  • Monitor for cardiac arrhythmia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What will be checked before amputation surgery?

A
  • Physical examination
  • X-ray
  • CT scan
  • Medication history
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What will be undertaken on the day of the surgery before operating?

A
  • Pulse monitored
  • BP taken
  • Cannulation
  • Anaesthesia
  • Surgery
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What will be undertaken post-surgery?

A
  • Continuous BP and pulse
  • IV drip
  • Healing of wound
  • Oxygen
  • Pain relief
  • Physical therapy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the ascending tract that transmits pain perception?

A

Spinothalamic tract:
Stimulus activates cytokine release
This activates an action potential in sensory nerve fibres and carry impulses to the dorsal horn of the spinal cord
Synapse with secondary neurons at the dorsal horn
Secondary neuron runs up the spinothalamic tract contralaterally and synapse at the thalamus
Tertiary neurons relays information to the somatosensory cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the descending pathway involved in pain modulation?

A
  • Neurons arise from periaqueductal grey matter in the spinal cord and come down to synapse at the nucleus raphe magnus
  • Secondary neuron can control the conduction of the ascending pathway within the substantia gelatinosa
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the idea of gate control theory?

A

Proposed by Melzack and Wall
The gate is a machnism where pain can be let through if open. It can also be closed.
If the gate is closed, the pain signals will be restricted travelling up to the brain, and the perception of pain won’t be perceived
Application of a non-noxious stimulus e.g. light rubbing may reduce the pain.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the proposed mechanism of the gate control theory?

A

Deep touch activates pacinian corpuscules in the dermis of the skin e.g. rubbing skin
Signal is transmitted by the DCML ascending ipsilaterally to the MO
Decussates in the medial leminiscus in the MO
The DCML can activate inhibitory neurons which can release enkephalin which bind to opioid receptors in the post synaptic membrane of the neuron
Causes closure of calcium channels, which reduces excitatory neurone e.g. glutamate and substance P release from primary neuron
Reduced excitation of secondary neurones, depolarisation and reduced firing of APs sent to the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What are the theories of phantom limb pain?
Cortical reorginsation: Area of the somatosensory cortex still responds to signals from the missing limb due to stimulation of other neurons nearby Nerve damage: damage to peripheral nerves during amputation leads to abnormal signalling resulting in perception of pain in the missing limb Psychological factors: cognitive factors may exacerbating or alleviate phantom pain. Retaining memories of pain experiences which can persist even after the cause of the pain is removed
26
What is the pharmacology of morphine?
Primary targets: mu, kappa and delta receptors which are GPCRs. Modulate calcium channel activity Secondary target: Lymphocyte antigen 96 (pharmacolohical effect unknown)W
27
What is the physiology of morphine?
Morphine binds to opioid receptors: mu, kappa, delta Causes inhibition of pain signals Normally excitatory NTs are released e.g. glutamate, substance P and CGRP which promote pain signalling by exciting second-order neurons in the dorsal horn which cause excitation, propagating signals Activation of opioid receptors causes closing of Ca2+ channels in presynaptic neuron, decreases release of NTs, cause K+ efflux
28
What are the side effects of morphine?
Nausea: stimulation of CRT in MO Constipation, light-headedness, dizziness Respiratory depression
29
What are the types of fractures? 9
Avulsion: small fragments puled away by tendons/ligaments Comminuted: break into multiple fragments Compound: open, bone penetrates the skin Greenstick: incomplete break, bone bends Impacted: one end of broken bone is driven into interior of other fragment Linear: straight line across the bone Oblique: diagonal break across bone Spiral: spiralling break along length of bone Transverse: break perpendicular to axis of bone
30
How can fractures be repaired?
Closed reduction and immobilisation: manipulating bones from outside before using cast/brace/splint Open reduction and internal fixation: open surgery to reposition bone to correct position to place plates, rods, screws to fix position External fixation: metal pins or screws into bone and connecting them externally to a rigid frame Traction: applying force using a system of weights and pulleys to align bone - temporary before treatment Functional bracing: brace to support fracture, allows some movement Intramedullary nailing: long metal rod inserted into medullary canal of long bone
31
How is amputation carried out?
General anaesthetic laid on back for accessibility Circumferential incision to create skin flaps - leaving as much healthy tissue as possible Muscles dissected and retracted to expose bone Bone is cut with a saw. End is smoothed over All soft tissue handled carefully to minimise postoperative complications Nerves cut to prevent painful neuromas Skin flaps stapled over wound and drains placed over to prevent fluid accumulation
32
What are the stages of wound healing? - Haemostasis
Haemostasis: driven by tissue hypoxia. Smooth muscle constricts > damaged arteries constrict > reduce BF > tissue hypoxia and acidosis Thromboxane A2 released by platelets, endothelin released by endothelial cells > coagulation
33
What are tha stages of wound healing? - Inflammation early phase
Mast cells deregulate releasing histamine (H1) > increases vascular permeability for inflammatory cells (neutrophils) to enter wound Neutrophils - phagocytosis, degranulation, NETosis Complement cascade activated
34
What are the atgaes of wound healing? Inflammation late phase
Monocytes differentiate into macrophages First days they are M1: pro-inflammatory Later become M2: anti-inflammatory - drive tissue repair Growth factors activated PDGF, FGF, VEGF > collagen secretion to form granulation tissue Collagenases released to breakdown and allow for remodelling Dendritic epidermal T cells : located in epidermis and stimulate keratinocytes to secrete growth factor. IGF1 causes them to differentiate Lipoxins : enable efferocytosis - macrophages engulf them to differentiate
35
What are the stages of wound healing? Proliferation
Angiogenesis: centre of wound is avascular. VEGF secreted via HIF-1 pathway Fibroblast proliferation and migration: fibroblasts lay down the ECM proteins for providing strength to new tissue. Fibroblasts change to myofibroblasts to connect surrounding cells and ECM proteins - pull wound closed Re-epitheliasation: cytokines and GFs stimulate basal epithelial cells at wound edge to migrate across wound bed. Epithelial-mesenchymal transition allows cells to move across wound surface Wound contraction: mediated by myofibroblasts which close the wound by pulling wound edge together
36
What are the stages of wound healing? Remodelling
Balance between collagen synthesis and degradation Can take up to 2 years
37
Name the stages of bone healing post fracture
Haematoma formation Inflammation Soft callus Hard callus Remodelling
38
Stages of bone healing - Haematoma formation
Coagulation occurs in between and around broken bones > stabilises the fracture Growth factors released from platelets Haematoma enables haemostasis
39
Stages of bone healing - inflammation
Vasodilation and increased vascular permeability enables neutrophils to enter fracture and phagocytose necrotic tissue Formation of granulation tissue - new ECM Osteoprogenitor cells migrate to bone M2 macrophages drive resolution of inflammation Fibroblasts migrate to site
40
Stages of bone healing - soft callus
Fibroblasts, chondroblasts > chondrocytes > collagen laid down to form fibrocartilagenous matrix Osteblasts recruited from intact periosteum Angiogenesis - supporting vessels connect into callus
41
Stages of bone healing - hard callus
Soft cartilaginous callus resorbed > cartilage calcified, osteoblasts active, type 1 collagen laid down > woven bone Vasculature matures
42
Stages of bone healing - remodelling
Woven bone > lamellar bone Osteoclasts resorb bone, osteoblasts lay down new matrix Woven bone (disorganised collagen) into lamellar bone (organised collagen) Increased mineralisation Bone highly vascularised with marrow in core
43
What factors affect wound healing?
Hypoxia Smoking Infection Immunosuppression Chronic disease Wound management Age
44
How can hypoxia affect wound healing?
All wounds are hypoxic to some extent Sufficient oxygen is needed for collagen deposition Low oxygen and nutrient supply can lead to necrosis of bone and soft tissue
45
How can smoking affect wound healing?
Affects chemotaxis, migratory function and oxidative bactericidal mechanisms in inflammatory phase Reduces fibroblast migration and proliferation Down-regulates collagen synthesis and deposition
46
How can infection affect wound healing?
Delayed primary closure or closing by tertiary intention should be considered when suturing contaminated wounds
47
Chronic disease and wound healing
COPD can affect oxygen supply required for wound healing Hyperglycaemia can affect cell function MMPs expression and function is altered in diabetes Uncontrolled diabetes causes long term microvascular damage which affects O2 levels and nutrient supply
48
How does age affect wound healing?
Elderly have a thinner epidermal layer and slower inflammatory, migratory and proliferation response due to cell senscence
49
Imaging of an X-ray
High energy electromagnetic radiation X-rays are absorbed in different amounts by different density tissues Low density structures - appear black High density structures - appear white
50
What are the pros and cons of xrays?
Pros: - Quick - Cheap - Portable - Low dose radiation Cons: - Cant identify soft tissue injuries - Type and grade of malignancy
51
CT scan imaging
Computerised X-ray imaging Narrow beams of X-rays are aimed at patient and rotated around body to generate cross sectional images Successive cross sectional images are stacked together
52
What are the pros and cons of CT scan?
Pros: - Quick - Cheap - Excellent anatomical detail and ability to exclude pathology Cons: - High dose of radiation - Requires constrats - Doesn't visualise soft tissues very well
53
Doppler US imaging
Use sound waves to detect how well blood flows through vessels Can examine arteries and veins Sound waves sent through a transducer and bounced off erythrocytes flowing through blood vessels - estimates speed of blood flow by measuring the pitch change
54
What are the pros and cons of doppler ultrasound?
Pros: - Quick - Cheap - Portable - No radiation Cons: - Not good for imaging deep structures - Affected by gas filled spaces
55
MRI imaging
Magnetic resonance to produce 3D image Use radio waves and magnetic field to produce image Good soft tissue contrast and can detect extent of rhabdomyolysis
56
What are the pros and cons of MRI?
Pros: - High amount of detail of soft tissue - Doesn't require contrast - No radiation Cons: - Expensive - Takes long time - Relies on patient being completely still
57
What are the time terms used in trauma?
Golden hour - immediately after an injury where prompt and coordinated care within trauma care can save lives Platinum 10 minutes - focus on limiting time spent on scene. Prioritises immediate life threatening physiology, followed by rapid transport to definitive care
58
What is the trauma system?
Arrive at scene Assess patient ABCDE approach Prophylactic antibiotics and analgesics - IV co-amoxiclav within 1 hour. Codeine or IV paracetamol/morphine Immobilisation Referral - paramedics decide where to refer patient using anatomical criteria, mechanism of injury
59
Who is part of the trauma team?
- Trauma team leader: ED consultant priotises care - Airway doctor: anaesthetic consultant - manage airway and ventilation - Primary survery doctor: ED registrar primary survey, vital signs and reports findings - Procedure doctor: ED registrar/junior doctor - prepares IV and IO access - Scribe: ED nurse - assembles resus docs Specialist teams, drugs nurse, monitoring nurse, procedure nurse, runner, radiograher
60
What is a reversed autologous saphenous vein graft bypass?
Reversed: veins have valves, so need to be reversed so they don't obstruct BF Autologous: obtained from same patient Great saphenous vein is used to replace any part of an artery as it is easily harvested and easy to use due to large diameter and length
61
How is a vein graft bypass carried out?
Clamp arteries to stop blood flow Graft sown to either end - bypass the damaged area to allow adequate blood supply to lower legs
62
What are alternative to a saphenous vein graft bypass?
Human umbilical vein In situ GSV graft - vein not reversed but valves individually incised Prosthetic materials Angioplasty - balloon to open up occluded artery
63
Why may there be graft failure?
- Wall thickening - Decreased diamtere - Varicosities - Increased vein branching - Local cellulitis/thrombocephalitis - Venous thrombosis - most common complication
64
What are the risks of bypass?
- Bypass not work adequately - Damage to nerve > numbness or pain in leg - Damage to nearby organ - XS bleeding - Infection at surgical site - Need for second bypass surgery or leg amputation
65
What is the target of physiotherapy for an amputee?
Relieve pain Promote healing Relieve muscle tension in surrounding muscles of stump For opposite limb for problems due to over-use Prepare for prosthesis
66
What may physiotherapy involve in the acute post-operative stage?
- Assess respiratory complications: breathing excercises to move secretions - Exercises in bed: increase ROM, promote healing - Assessment for walking aids/wheelchair - Advice on stump care, pain relief, PLP
67
Why is there a assessment for prosthesis eligibility?
Not suitable for frail people/ severe conditions as requires intense physiotherapy and energy to adjust
68
What may physiotherapy involve in pre-prosthesis rehabilitation?
- Skin desensitisation: tapping, rubbing skin to prevent sensitivity and XS scarring, compression bandages - Exercise program - ROM - Strengthening program - Walking with a PPAM aid - learn to walk with a prosthesis, balance - Teach transfers
69
What may physiotherapy involve in rehabilitation with a prosthesis?
- Practice donning prosthesis - Upper limb and core strengthening - Teach balance and biomechanics of prosthesis - Teach running, jumping
70
What are the different types of prosthesis?
Cosmetic: silicone restorations, include wrinkles, veins, knuckle definition Body powered: body controls the prosthetic Motor powered: battery and buttons can control movements of hand and fingers Myoelectric powered: Electrode against skin can detect electrical signals sent to residual muscles to move hand with the brain
71
What is the fitting process of prosthesis?
1) Mold of residual limb with plaster/fiberglass bandages/digital imaging 2) mold used to make a positive model of the stump 3) socket formed around the model 4) Tested for comfort, stability, function in a diagnostic prosthesis 5) Components assembled and design finalsied
72
What prosthesis are available on the NHS?
As of 2022, myoelectric bionic prosthesis are available on the NHS for eleible patients - with sufficient residual muscle. Silicone convers not available as these are heavy and can affect function of joints of prosthesis
73
What do OTs help amputees with?
- Teach techniques for everyday tasks - Advice on small aids -for small everyday tasks - Advice on larger aids e.g. wheelchair - Suggest home modifications - Advice on travel/vehicles - Facilitate return to work/hobbies - Create fatigue management programmes - Build confidence/self esteem
74
What psychiatric conditions may amputees suffer with?
Anxiety: effect of amputation, stigma, change in body image Depression: grief of lost limb, loss of hop for returning to normal life, loss of dignity PTSD: most common in war veterans and accident survivors. Intrusive thoughts, recollections, nightmares. Phantom limb pain: experienced by 90%. Mirror therapy, VR therapy, TENS.
75
What is CBT and what does it come from?
Beck's cognitive therapy: focus on distortions and thought processes that lead to negative behaviours. Interactions between negative views about oneself, future and the world CBT: one step further to change behaviour - restructure negative thought cycles

Unit 11 PBL cases (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions