Week 7 Flashcards
The vascular system is comprised of
Arteries and arterioles
Capillaries
Veins and venules
Lymphatic vessels
The vascular system depends on
Cardiovascular system Systemic blood vessels Circulating blood (volume/viscosity) Nervous & endocrine system activity Metabolic tissues needs Lymphatic system
Vascular system
Function:
To meet the circulatory needs of the tissues
Constantly changing according to metabolic requirements
When supply doesn’t meet demand = ischaemia
How?
Blood flow (from high pressure to low pressure)
(from arterial [~100mmHg] venous [~4mmHg])
Flow rate = ΔP/R (pressure difference ÷ resistance)
Capillary Fluid exchange
Hydrostatic (blood pressure)/osmotic pressures (proteins)
Any extra between arterial supply & venous reabsorption lymph
Imbalance = oedema
Peripheral blood flow
Flow rate = ΔP/R! Affected by:-
Hemodynamic resistance
Blood viscosity
Vessel diameter
Regulation of peripheral vascular resistance
CNS (sympathetic = vasoconstriction)
Hormonal (noradrenaline/adrenaline/angiotensin)
Chemicals/proteins/hypoxia/pH
Movement of fluid across the capillary wall:
To meet metabolic needs
Hydrostatic & osmotic force
Pathophysiology heart failure
Left:
Pulmonary congestion & reduced cardiac output
Poor arterial blood supply
Right:
Venous congestion & ? reduced cardiac output
Pathophysiology alteration in vessel supply
Lymph/arterial/venous Intact Rupture – aneurysm/trauma Patent Atherosclerosis/thrombus/valve issues Responsive Vasospasm/arteriosclerosis/aging changes
Clinical manifestations of peripheral arterial disorders
Intermittent claudication
Pulses diminished or absent
Oedema – None/minimal
Skin changes: Trophic – cold/dry/shiny/hairless/thick opaque toe nails
Pallor when elevated
Red when dangling (dependent rubor)
Ulcers – tips of extremities/ painful/deep/circular/pale to black base or dry gangrene
Clinical manifestations of peripheral venous disorders
Pain: aching to cramp like, relieved by activity/elevation
Pulses usually present
Oedema – present/increases at the end of day
Skin changes: warm/thick/ tough/darkened/? dermatitis
Ulcers – medial malleolus/ pain variable/ superficial/irregular border/granulation base
Assessment of intermittent claudication
Muscular/cramping (ischaemic) type pain Precipitated by exercise Resolves within 10 mins of rest Reproducible Area depend on which vessel affected Lack of blood supply of oxygen/nutrients when increase in demand Caused by arterial supply failure Anaerobic cellular metabolism
Common sites of Atherosclerotic Obstruction
Coronary arteries Carotid arteries Aortic bifurcation Iliac and common femoral arteries Distal popliteal artery
Modifiable risk factors for peripheral arterial disease
Smoking Diet Hypertension Hyperlipidaemia Diabetes Obesity Stress Sedentary lifestyle C-reactive protein (inflammation) Hyperhomocysteinemia (clotting factor)
Non-modifiable risk factors for peripheral arterial disease
Age
Gender
Familial predisposition/genetics
Nursing assessment of PAD
Health history Medications Risk factors Clinical manifestations of arterial insufficiency Claudication and rest pain Colour changes Weak or absent pulses Skin changes and skin breakdown Arterial/venous/lymphatic (medical) diagnosis made
Diagnosis of PAD
Altered peripheral tissue perfusion
Chronic pain
Risk for impaired skin integrity
Knowledge deficient
Planning of PAD
Major goals include: Increased arterial blood supply Promotion of vasodilatation Prevention of vascular compression Relief of pain Attainment or maintenance of tissue integrity Adherence to self-care programme
Implementation of PAD
Exercises and activities:
Walking (stop with pain – gradually increase tolerance)
Graded isometric exercises.
Promote circulation & development of collateral circulation
Specialist advice before commencement
Contraindications include leg ulcers/cellulitis/thrombotic occlusions
Positioning strategies
Temperature
Effects of heat (vasodilation) & cold (avoid)
Stop smoking
Stress reduction (counselling)
Due to poor nutrition & oxygen supply the extremities are susceptible to injury/infection/poor healing
Protection of extremities and avoidance of trauma
Good hygiene/gentle soap/moisturisers
Regular inspection of extremities (infection/inflammation)
Podiatric care (foot wear/nail care)
No constricting clothing
Good nutrition/stop smoking
Weight reduction as necessary
Nurse - Patient education essential
Complications of PAD
Atrophy of skin/nerves /muscles
Delayed healing/wound necrosis/infection/gangrene
Medical treatment for PAD
Medical (relieve symptoms/improve arterial supply)
Risk factor modification (smoking/diet/exercise)
Drugs (aspirin …/prostaglandin)
Management of diabetes/hypertension/obesity
Refer to podiatrist/physio/rehab. speciallist
Surgical (relieve symptoms/improve arterial supply)
PTBA (balloon angioplasty/stent)
Peripheral arterial bypass graft (femoral-popliteal)
Endarterectomy/patch graft
Amputation (last resort)
Nursing Management – Peripheral arterial bypass graft
Vital signs/neurovascular observations (pulses) Graft patency obs (doppler) Ankle brachial index (8hrly) IDC 1hrly measures Complex invasive line care Wound care (bleeding/haematoma) Elevate extremity/gently exercise Graduated compression stockings(?) Analgesia Discharge advice/patient education Care of co-morbidities
Aortic aneurysm
An aneurysm is a localised sac or dilation formed at a weak point in the wall of the aorta.
Type: True – wall of artery forms the aneurysm False – disruption of all artery layers (trauma/infection) Shape Position (thoracic 85%)
Risk factors for aortic aneurysm
Atherosclerosis in most cases Genetic link/congenital vessel wall weakness Trauma/disease/inflammation After formation - tends to enlarge Smoking/hypertension
Clinical manifestations of aortic aneurysm
(often asymptomatic/varied)
Pain/throbbing/”beating”
Ascending – voice hoarseness/dysphagia/venous return interruption (distended neck vessels/oedema)
Thoracic – deep spreading chest pain
Abdominal –back pain/bowel pressure/bruit/palpable
From thrombosis of smaller vessels
Diagnosis of aortic aneurysm
Routine examination
Pulsatile mass in 80% cases/bruit
Chest x-ray – calcification/widening of aorta
ECG to rule out MI
Echocardiology – aortic insufficiency
Ultrasound/ CT scan/MRI scan
Angiography – useful to assess other vessel involvement
Medical management for aortic aneurysm
Depends on symptoms/prognosis/position/ patient co-morbidities
High rate of surgical death/complications
Prevent rupture/early detection essential
Conservative (small aneurysm/poor surgical risk)
Risk factor/behaviour modification (hypertension/smoking/sedentary lifestyle)
Manage co-morbidities & other atherosclerosis
Operative
Surgical - graft or primary closure
Endovascular – femoral/iliac artery catheter accessed
minimally invasive/strict criteria
Post op nursing care for an ascending aortic aneurysm
Complex major surgery/surgical ICU/HDU area
Patient may have complex co-morbidities
Vital signs/neurovascular – frequent/regular
Monitoring for signs of occlusion/thrombosis/emboli
Monitor all systems (respiratory/renal – IDC 1 hrly)
Monitor T° 4 hrly (graft rejection)
Assess site/wound – haematoma/ooze/inflammation
Often first or second day post op walking
Surgeon/facility dependent
Risk factors for deep vein thrombosis
over 35 years smoker family history oral contraceptive obesity
Clinical manifestations of DVT
Maybe nil or non specific
Unilateral pain/warm/erythema
Systemic T°/tender/Homan’s sign
DVT prevention/prophylaxis
Early mobility/ambulation/SOOB
Bed exercises/deep breathing & coughing/alter position
Compression stockings/(good for distal DVT but what about proximal)? – Fit correctly!!!!
Pneumatic compression devices - SCDs/ICDs
Drugs
Anticoagulants - Heparin(LMWH)/enoxaparin/warfarin (phasing out)/others
No prophylaxis – 26% patients developed DVT
Stockings alone – 13% patients developed DVTs (50% )
Stockings and anticoagulants – only 4% patients developed DVTs
DVT treatment
Prevent further growth & fragmentation (into PE)
Bed rest with limb elevation
Anticoagulants (prevent further thrombi)
Thrombi resolves naturally (not through anticoags)
Then mobilise with quality stockings (not the cheapies)
Drug Therapy
Heparin – IV infusion/SCI/Warfarin/more modern types
Thrombolytics
Previously (with DVTs) only for limb threatening situations
Now being trialled to ascertain treatment as more routine
Surgery (uncommon):
Vena cava filter
Open thrombolectomy
Contraindications of Pneumatic Compression Devices/stockings
The obese (can’t fit them correctly/tourniquet the limb!)
Heart failure
Assess your patient/history
Certain conditions/diseases of the lower limbs
Diabetic neuropathy
Severe oedema of the lower limb
Adverse events of pneumatic compression devices
Nerve palsies Common peroneal nerve palsy Paraesthesia of legs/feet Compartment syndrome Pressure ulcers Slipping while walking (wear shoes/slippers!)
