PATHO exam 3 (week 7 chapter 26)

Aneurysm

Abnormal and localized dilation of a blood vessel. One small segment that has outpatching/enlargement. Causes more turbulent flow to the spot, increases amount of pressure applied to area. Commonly found on aorta and different areas of the brain.

Berry Aneurysm

Most often found in the circle of Willis in the brain circulation. Consists of small, spherical vessel dilation. Round outpouching at spot where vessel splits. Commonly found at bifurcations.

Fusiform and Saccular Aneurysm

Characterized by gradual and progressive enlargement of the aorta. Increased tension, increased dilation. Saccular is sac-like. Fusiform is elongated. Commonly found on thoracic and abdominal aorta. Can’t clip, have to graft or stent.

Disecting Aneurysm

Acute, life-threatening conditions. Hemorrhage into the vessel wall with longitudinal tearing (dissections) of the vessel wall to form a blood-filled channel between the different layers of the vessel wall. Further weakens impacted area. Increased vessel wall tension. Turbulent flow. Outpouching with thinner wall. High risk for vessel to rupture, where blood exits vasculature and bleeds out into areas where it shouldn’t be. Limited time to intervene.

Disorders of the Venous Circulation

Produce congestion of the affected tissues (pooling of blood). Will see swelling because of extra fluid in peripheral system (lower extremities). Predispose to clot formation. Stagnation of flow. Activation of the clotting system.

Varicose veins

problem with valves (return of blood to heart), backflow of blood

Thrombophlebitis

inflammation of vein caused by blood clot within it

Virchow’s Triad Associated with Venous Thrombosis

Increase the risk for venous thrombosis. Having one increases risk of clot, but having them together is more significant.

-Stasis (stagnation) of blood

-Increased blood coagulability

-Vessel wall injury

Deep Vein Thrombosis (DVT) Prevention

Early mobility. Exercising legs. Support stockings. Sequential compressive device (SCDs) (pulsatile squeeze). Prophylactic anticoagulation (i.e. Heparin). Don’t massage leg if DVT is suspected.

DVT Assessment

Homan’s sign (patient extends leg, then lifts toward nose, will have pain in calf or behind knee). Confirm with Doppler study.

Blood Flow

Requires that arterial pressure is greater than venous pressure. Requires that arterial, venous, and capillary pressures are greater than the pressure surrounding the vessels to avoid collapse of the vessels.

Compartment Syndrome

Outside pressure around vessels becomes greater than the pressure inside the vessels. Increased pressure in anatomic space that cannot expand. Caused by decrease in compartment size or increase in compartment volume. Swells so much, pushes down vessels. Common in soft tissue injury, burns or excessive edema. Must intervene. May need fasciotomy.

Pressure Injuries

Four stages. Ischemic lesions of the skin and underlying tissues. Caused by compression of blood vessels due to external pressure (immobility). External pressure that compresses blood vessels. Friction and shearing forces that tear and injure blood vessels. Could also include mucosal injuries, DTI, unstageable ulcers, equipment-related injuries, etc.

Stage 1 Pressure Injury

Highest risk. Persistent red, blue, or purple tones. No open areas. Doesn’t disappear when pressure is relieved.

Stage 2 Pressure Injury

Partial thickness skin loss, including epidermis.

Stage 3 Pressure Injury

Full-thickness skin loss extending through the epidermis and exposing subcutaneous tissue/fat. Presents as a deep crater.

Stage 4 Pressure Injury

Full-thickness skin loss with extensive destruction, necrosis, or damage to muscle, bone, or other substances. Can see bone.

Primary (essential) Hypertension

The chronic elevation in blood pressure that occurs without evidence of other disease. Diet, lifestyle, genetic.

Systolic/diastolic hypertension

Both the systolic and diastolic pressures are elevated

Diastolic hypertension

The diastolic pressure is selectively elevated

Systolic hypertension

The systolic pressure is selectively elevated

Secondary Hypertension

The elevation of blood pressure that results from some other disorder. Many conditions that cause secondary hypertension can be corrected by surgery or specific medical treatment.

Malignant Hypertension

An accelerated form of hypertension that develops rapidly. Sudden elevation. Diastolic >120 may be life threatening. Can cause organ damage.

Regulation of Blood Pressure

Neural mechanisms. Baroflex and chemoreceptor (mediated reflex). Arterial chemoreceptors. Renin-Angiotension-Aldosterone. Vasopressin (ADH).

Treatment for HTN

Weight control. Low salt diet. Exercise. Add medication if needed: Diuretics (increase urination), Beta blockers (decreased heart rate), Calcium channel blockers, ACE inhibitors (blocks Ag1->Ag2).

Normal BP

<120 systolic and <80 diastolic

Elevated BP

120-129 systolic and <80 diastolic

Stage 1 HTN

130-139 systolic or 80-89 diastolic

Stage 2 HTN

Greater than 140 systolic or greater than or equal to 90 diastolic

Orthostatic Hypotension

An abnormal decrease in blood pressure on assumption of the upright position. Body doesn’t respond fast enough to change. A drop of 20mmHg systolic or 10mmHg diastolic.

Symptoms of Orthostatic Hypotension

Dizziness, Heart rate increase of 30 or more minutes, Visual changes, Head and neck discomfort, Poor concentration while standing, Palpitations, Tremor, anxiety, Presyncope, and in some cases syncope (feel like passing out).

Causes of Orthostatic Hypotension

Decrease in venous return to the heart due to pooling of blood in lower part of the body. Inadequate circulatory response to decreased cardiac output and a decrease in blood pressure. Conditions that decrease vascular volume (dehydration). Conditions that impair muscle pump function : bed rest, spinal cord injury. Conditions that interfere with cardiovascular reflexes: medications, disorders of autonomic nervous system, effects of aging on baroreflex function.

Causes of Orthostatic Hypotension Related to Hypovolemia

Excessive use of diuretics. Excessive diaphoresis. Loss of gastrointestinal fluids through vomiting and diarrhea. Loss of fluid volume associated with prolonged bed rest.