CORONARY STENTS

Coronary angioplasty also called percutaneous coronary intervention is a procedure used to open clogged heart arteries. Angioplasty involves temporarily inserting and inflating a tiny balloon where your artery is clogged to help widen the artery.It is often combined with the permanent placement of a small wire mesh tube called a stent to help prop the artery open and decrease its chance of narrowing again.Doctors have been using stents to clear blocked arteries for the past 20 year.

Different types of Coronary Stents

There are three major types of coronary artery stents: 

#1.Bare metal stents (BMS)
#2.Drug-eluting stents (DES)
#3.Bioresorbable Vascular Scaffold stents (BVS).

BMS-The bare metal stent has mesh qualities and does not have medication attached in or outside of the stent. This stent represents the first generation of stents.The mesh stent has proven itself, as many people have received this type of stent and live normal lives without chest pain. Once the surgeon installs this type of stent, the person will need to take anti-coagulants and blood thinners such as aspirin.

DES-The drug-eluting stent works by including medication within the stent. This makes it a step up from the usual plain mesh metal stent. This medication keeps the stent from becoming blocked after a period of time.The person with the drug-eluting stent needs to change the lifestyle and follow a strict medical regime in order for the stent to have the desired effect.

BVS- This Bioresorbable Vascular Scaffold stent is made up of polylactide- a bio- compatible material that is generally used in dissolving sutures.This is a stent that dissolves after it finishes doing its job.It starts dissolving in the body after about 12 months and it takes anywhere between two and three years for it to completely dissolve.While these dissolvable stents are placed in the same location as a traditional stent, it takes slightly longer to insert a dissolvable stent, because the device is less flexible. 

What Stents To Use?

Stents cannot be used in all the cases of angioplasty because they are difficult to mould across tight bends in blood arteries that are badly clogged with plaque. The decision on which type of stent to use should depend on the persons symptoms, and on the size and shape of the narrowed part of the artery.

*DES were introduced in response to the high observed incidence of late stent re-stenosis with BMS. Re-stenosis is a side-effect of the normal healing process with the growth of scar tissue around the stent mesh in a process called neointimal hyperplasia, which in some cases, can lead to occlusion of the coronary lumen. The process peaks at around the third month and reaches a plateau at between 3 and 6 months after the procedure.

A drug-eluting stent should be used if the person has angina, and the inside diameter of the artery is less than 3 mm across, or the narrowed area is more than 15 mm long. There are several different drug-eluting stents, which contain different drugs.If more than one artery is narrowed, doctors should make the decision on which type of stent to use for each artery separately.

*The BVS dissoving stent has an advantage of " No metal left behind" which means a lower risk of clotting and stent fractures.

With the advancement in technology and research, the quality of the stents is improving and its cost is decreasing steadily.

CELLULITIS

Cellulitis is a skin infection caused by bacteria. Normally, your skin helps protect you from infection. But if you have a cut, sore, or insect bite, bacteria can get into the skin and spread to deeper tissues. If it is not treated with antibiotics, the infection can spread to the blood or lymph nodes. This can be deadly.

Some people can get cellulitis without having a break in the skin. These include older adults and people who have diabetes or a weak immune system. These people are also more likely to develop dangerous problems from cellulitis. And they are more likely to get cellulitis again.

Causes

The skin is a good barrier against infection. However, a break in the skin from a cut, skin ulcer, injection, athlete's foot, scratch, etc, is a way in which bacteria (germs) can get into and under the skin. A tiny cut is all that is needed to allow bacteria in.

We all have some bacteria that live on our skin which normally do not cause any problems. However, if your skin is damaged or broken in some way, the bacteria can get in. The bacteria may then multiply and spread along under the skin surface to cause an infection. A cut, graze, etc, is found in many cases to be the root cause. However, sometimes the infection occurs for no apparent reason with no break in the skin found. Various different types of bacteria can cause cellulitis.

Signs and symptoms

Nonpurulent cellulitis is associated with the 4 cardinal signs of infection, as follows:

• Erythema
• Pain
• Swelling
• Warmth

Physical examination findings that suggest the most likely pathogen include the following:

• Skin infection without underlying drainage, penetrating trauma, eschar, or abscess is most likely caused by streptococci; Staphylococcus aureus,often community-acquired MRSA, is the most likely pathogen when these factors are present.
• Violaceous color and bullae suggest more serious or systemic infection with organisms such as Vibrio vulnificus or Streptococcus pneumoniae

The following findings suggest severe infection:

• Malaise, chills, fever, and toxicity
• Lymphangitic spread (red lines streaking away from the area of infection)
• Circumferential cellulitis
• Pain disproportionate to examination findings

Indications for emergent surgical evaluation are as follows :

• Violaceous bullae
• Cutaneous hemorrhage
• Skin sloughing
• Skin anesthesia
• Rapid progression
• Gas in the tissue

Diagnosis

Diagnosis is usually fairly straightforward and does not generally require any complicated tests. A GP (general practitioner, primary care physician) can do this. The doctor will examine the patient and assess the symptoms. The number of cases where Lyme disease has been misdiagnosed as staph- or step-induced cellulitis is growing. 

It is important to discard the possibility that some other condition may have caused the symptoms, such as varicose eczema. 

The doctor may take a swab (sample) if there is an open wound. This will help him/her find out what type of bacteria it is. 

Treatment

Cellulitis treatment usually is a prescription oral antibiotic. Within three days of starting an antibiotic, let your doctor know whether the infection is responding to treatment. You'll need to take the antibiotic for up to 14 days. In most cases, signs and symptoms of cellulitis disappear after a few days. If they don't clear up, if they're extensive or if you have a high fever, you may need to be hospitalized and receive antibiotics through your veins (intravenously).

Usually, doctors prescribe a drug that's effective against both streptococci and staphylococci. Your doctor will choose an antibiotic based on your circumstances.

No matter what type of antibiotic your doctor prescribes, it's important that you take the medication as directed and that you finish the entire course of medication, even if you start feeling better.

Your doctor also might recommend elevating the affected area, which may speed recovery.

After treatment the patient needs to come back for a follow-up so that the doctor can confirm that the treatment has worked.

Points to remember

Cellulitis is a spreading, acute inflammation of the dermis and subcutaneous tissue, sometimes involving muscle. Hallmarks are erythema, edema, tenderness, and warmth

Risk factors include diabetes mellitus (type 1 and type 2), immunocompromised state, alcoholism, intravenous drug abuse, and a prior history of cellulitis. A history of surgery resulting in disrupted lymphatic drainage predisposes to recurrent episodes (eg, saphenous vein harvesting for coronary artery bypass grafting or mastectomy and axillary node dissection)

The infectious agent is most frequently Streptococcus pyogenes orStaphylococcus aureus

First-line therapy includes oral antibiotics with good coverage of Gram-positive organisms

Outpatients placed on oral antibiotic therapy should be re-evaluated 24 to 48 hours after starting therapy to assess response to therapy

Suspected necrotizing infection, deep or quickly spreading infection (particularly on the face and hands), and orbital cellulitis require referral for further investigation and treatment

PULMONARY EMBOLISM

A pulmonary embolism is a sudden blockage in a lung artery. The cause is usually a blood clot in the leg called a deep vein thrombosis that breaks loose and travels through the bloodstream to the lung. Pulmonary embolism is a serious condition that can cause permanent damage to the affected lung,low oxygen levels in your blood and  damage to other organs in your body from not getting enough oxygen.If a clot is large, or if there are many clots, pulmonary embolism can cause death.

Causes

Blood clots can form for a variety of reasons. Pulmonary embolisms are most often caused by deep vein thrombosis, a condition in which blood clots form in veins deep in the body. The blood clots that most often cause pulmonary embolisms typically begin in the legs or arms.

Factors that increase a person’s risks of deep vein thrombosis and pulmonary embolism include:

• cancer
• a close family member with a history of embolisms
• fractures of the leg or hip
• genetic blood clotting disorders (hypercoagulable states), including Factor V Leiden, prothrombin gene mutation, and elevated levels of homocysteine
• a history of heart attack or stroke
• major surgery
• obesity
• a sedentary lifestyle

Symptoms

Pulmonary embolism symptoms can vary greatly, depending on how much of your lung is involved, the size of the clots (almost never single) and your overall health — especially the presence or absence of underlying lung disease or heart disease.

Common signs and symptoms include:

• Shortness of breath. This symptom typically appears suddenly and always gets worse with exertion.
• Chest pain. You may feel like you're having a heart attack. The pain may become worse when you breathe deeply (pleurisy), cough, eat, bend or stoop. The pain will get worse with exertion but won't go away when you rest.
• Cough. The cough may produce bloody or blood-streaked sputum.

Other signs and symptoms that can occur with pulmonary embolism include:

• Leg pain or swelling, or both, usually in the calf
• Clammy or discolored skin (cyanosis)
• Excessive sweating
• Rapid or irregular heartbeat
• Lightheadedness or dizziness

Diagnosis

A detailed history of the patient is taken which includes general health, medical history and symptoms with a physical exam.To confirm the diagnosis of pulmonary embolism, the physician may order specific tests, which may include some of the following:

• Chest x-ray
• Electrocardiography (ECG) which measures your heart’s electrical activity
• D-dimer enzyme-linked immunosorbent assay, a blood test that shows an increase of a type of protein that may rise after a pulmonary embolism
• Lung scanning, which measures blood flow in your lungs and your air intake
• Spiral computed tomography (CT) scan
• Pulmonary angiography, which shows x ray pictures of the blood vessels in your lungs
• Duplex ultrasound, which allows your physician to measure the speed of blood flow and to see the structure of your leg veins
• Venography, which shows x-ray pictures of your leg veins

Treatment

Treatment options for pulmonary embolism include:

• Anticoagulants. Also described as blood thinners, these medications decrease the ability of the blood to clot. Examples of anticoagulants include warfarin (Coumadin) and heparin.
• Fibrinolytic therapy. Also called clot busters, these medications are given intravenously (IV) to break down the clot.
• Vena cava filter. A small metal device placed in the vena cava (the large blood vessel that returns blood from the body to the heart) may be used to prevent clots from traveling to the lung. These filters are generally used in patients who cannot receive anticoagulation treatment (for medical reasons), who develop additional clots even with anticoagulation treatment, or who develop bleeding complications from anticoagulation.
• Pulmonary embolectomy. Surgical removal of a pulmonary embolism. This procedure is generally performed only in severe situations in which the PE is very large, the patient either cannot receive anticoagulation and/or thrombolytic therapy due to other medical considerations or has not responded adequately to those treatments, and the patient's condition is unstable.
• Percutaneous thrombectomy. Insertion of a catheter (long, thin, hollow tube) to the site of the embolism, using X-ray guidance. Once the catheter is in place, the catheter is used to break up the embolism, extract it (pull it out), or dissolve it by injecting thrombolytic medication.

Prevention

The most effective way to prevent pulmonary embolism is to prevent DVTs from forming or starting to move in the blood vessels. If you have DVT, you may be prescribed an anticoagulant. Anticoagulants can also be given to people with DVT to prevent the condition. They can also protect against stroke.

Non-medication methods to help prevent DVT include using compression devices and compression stockings (to ensure blood doesn't pool in the legs), and frequently stretching, massaging, and moving your lower leg muscles if you are inactive for a long time. You can also reduce your risk factors for getting blood clots, for instance by quitting smoking and controlling your blood pressure.

Points to remember

• Pulmonary embolism usually is caused by a thrombus in the proximal deep veins of the leg that breaks off and lodges in the lung
• Patients may be asymptomatic or may present with typical symptoms, including dyspnea and chest pain. Patients with massive pulmonary embolism may present with hypotension, shock, or sudden death
• An integrated diagnostic approach involving clinical prediction rules and noninvasive testing can be used to evaluate patients in whom pulmonary embolism is suspected. Clinical prediction rules stratify patients into low, moderate, or high pretest probability of pulmonary embolism categories, which, in turn, helps to determine the need for further diagnostic testing
• The aggressiveness of treatment is dependent on the severity of pulmonary embolism. Treatment of nonmassive pulmonary embolism involves rapid initiation of anticoagulant therapy. Thrombolysis is indicated in patients who are hemodynamically unstable (massive pulmonary embolism). Surgical or angiographic embolectomy only should be done in experienced institutions
• Prevention of deep vein thrombosis (DVT) in hospitalized patients is crucial to preventing pulmonary embolism