Effects Of A Pressure Ulcer On The Skin Biology Essay

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The skin is an important part of our body because it protects all body organs in one way or another but it is easily injured as it is exposed to external factors that may damage it.

According to NICE an area where the skin and/or underlying tissue are damaged by any of the factors such as pressure, shear or friction is called a pressure ulcer,(Nice, 2005). The pressure ulcers may be caused by a combination between these external factors and the factors within the patients which are also very important.

The external factors are known as extrinsic factors. They include pressure, shear and friction, and they are the main causes of pressure ulcers. Whenever these factors are present, they damage the skin and underlying tissue on their own or in combination of the three, (Dealey, 2005).

The human body is made in such a way that it can stand high pressure for a very short period of time and after this time the pressure should be relieved to prevent damage or pressure sores appearing. When the soft tissue is compressed between a bone and a hard surface, a greater pressure than the capillary pressure is caused and the blood circulation of this area is disrupted. This is called ischaemia. The body response in a way that it changes its position to relieve the pressure and the area becomes red. This condition is known as reactive hyperaemia. This is a normal physiological response of the body and causes a temporarily increasing of its blood supply, removing wastes and carrying oxygen and nutrients, (Dealey, 2005).

If the pressure is not being relieved for a long period of time, the needed oxygen and nutrients can no longer reach the tissue cells and the lymphatic system cannot work properly to get rid of waste products. Continuous pressure therefore can cause dying of the tissue cells known as necrotic cells, (Dealey, 2005).

The parts of the body most vulnerable to developing the pressure ulcers are called the pressure areas as shown on the picture. They include the shoulders, back of the head, lower back, buttocks, heels, elbows and inner part of the knees.

Shear may cause damage of the skin and underlying tissue when the patient slides down the bed. Shear forces damage the tissue and blood vessels.

Friction is the pressure applied when two surfaces rub together such as the skin and a mattress. This is very common when the patient is wrongly dragged rather than lifted to move across the bed.

Moisture, such as sweating or incontinence of the patient may increase the effect of friction and cause more damage on the top layers of the epithelial cells, (Dealey, 2005).

Patients suffering from long term medical conditions are more vulnerable for developing pressure sores. Most vulnerable and affected are the elderly patients because their skin becomes thin and less elastic. This happens because the collagen, which is important to prevent disruption of the blood supply (microcirculation), is less. Reduced mobility predisposes the patients to develop pressure ulcers. This can be because of age, obesity, surgery or some medical illnesses.

Nutrition is also an important factor because poor nutrition (such as malnourishment or dehydration) can lead to anaemia and reduced oxygen supply to the tissues,(Dealey, 2005). This impairs the elasticity of the skin, therefore skin is more susceptible to pressure sores.

Some external factors increase the risk of pressure sores. They include inappropriate position (lying or sitting for a long period of time without changing position), poor moving and handling techniques or poor hygiene of the skin.

Question 2 Section B

Granulation and epithelialisation are signs of a healing pressure sore. Describe these two signs and explain the physiological changes underpinning the healing process.

The pressure ulcer's healing process passes over four phases: haemostasis, inflammation, proliferation or granulation and remodelling or maturation,(Jenkins, Kemnitz and Tortora,2010). This report will focus mainly on the last two phases - granulation and remodelling or epithelisation.

The pressure ulcer's healing starts roughly on the fourth day after its appearing and usually lasts until the 21st day but this depends on how big or deep the ulcer is. If the pressure ulcer is not treated appropriately, it can become chronic which is very difficult to treat.

This picture illustrates extracellular matrix.

The formation of granulation tissue starts during the inflammatory phase and continues to grow until the whole wound is covered. It looks like pebbled red tissue - rich of new blood vessels, endothelial cells, fibroblasts, myofibroblasts and other components of the formed extracellular matrix (ECM).

ECM is a connective tissue which surrounds and supports the cells. It is composed of proteins, such as collagen and elastin; specialized proteins, like fibrillin, fibronectin and laminin; and other components. Fibronectin and hyaluran are the two main components helping to create the new ECM and making cell migration easier,(Dealey,2005).

The cells involved in this regeneration are called fibroblasts. They produce growth factors and fibronectin which attract epithelial cells to the wound site.

The presence of granulation tissue is very important and helps the epithelial cells to migrate across this new tissue and form a barrier between the wound and the environment. The cells that are responsible for re-epithelisation are called keratinocytes. These specialized cells cannot migrate across if the granulation tissue is not formed yet. That is why in deep ulcers the epithelisation phase begins a bit later,(Dealey,2005).

Depending on how deep the ulcer is and how much the basement membrane is damaged, the epithelial cells start to replace by division and to migrate in the stratum basale,(Jenkins, Kemnitz and Tortora,2010).

Sometimes the basement membrane is destroyed at the wound site. In those cases the re-epithelisation begins from the wound margins or skin appendages. If those are damaged as well, the migration of the cells starts from the wound edges only.

Some chemicals, such as nitric acid, stimulate the migration of keratinocytes. They change their shape - become longer like ruffles before they start migrating, (Dealey,2005). The first epithelial cells which are attached to the basement membrane form the stratum basale. The size of the scar depends on how quickly the migration of the cells occurs, (Dealey,2005). The epithelial cells are able to phagocytise the dead tissue or bacteria.

The process of epithelisation does not stop until the whole surface is covered and migration of cells has finished. Keratinocytes then proceed to secrete proteins which form the new basement membrane, (Dealey,2005).

Question 4 Section A

Describe the effects of acute and chronic constipation on the structure and function of the digestive system.

The last stage of all activities of the digestive system is in the large intestine, which is large in diameter but short; it is about 1.5m (5 feet) long. In there, the indigestible food is prepared to be disposed out of the body,(Jenkins, Kemnitz and Tortora,2010).The water is absorbed and finally the waste material is stored for a short period in the colon. Normally this residue is stored there about 12 to 24 hours and when it is delivered to the rectum, it contains only indigestible food, mucus or bacteria and a little bit of water which will allow faeces to pass smoothly, (Jenkins, Kemnitz and Tortora,2010).

If for any reason the waste products stay in the large intestine for a longer period, the water continues to be absorbed from the stools and they become hard, dry and difficult to pass. This condition is called constipation and it is very common in adults,(Marieb,2009). Some people have a feeling of incomplete emptying after each bowel movement which can be accompanied by pain or cramps in the lower abdomen, or feeling sick in severe cases of constipation.

The normal bowel movement may be considered when the number of passing stools is between 3 and 21 per week but some people have irregular bowel movements which are still considered to be normal.

Acute constipation can be described as recent, causing short term problems of bowel movements or inability in passing stools. It requires urgent assessment if there are symptoms of rectal bleeding, nausea, vomiting or cramps because the cause could be very serious such as tumor of the colon, (Keshav,2004 ).

In some cases if the faecal material is too big or hard, it is possible to tear the anal skin when it passes through the rectum and anal fissure may appear. It is very painful and is accompanied with bleeding. The patient needs to follow an appropriate lifestyle and diet which will help keep the stool soft. Laxatives may be required to make the stool easier to pass. For some patients this condition could be very painful and need to be prescribed some ointment to manage this pain and to loosen the anal muscles and help the tissue to heal easily, (Keshav,2004).

Chronic constipation is when the laxatives are taken for a long period of time and the bowels are not likely to work well without medication. They become "lazy". Such a patient need to take regular laxatives otherwise this persistent constipation can cause severe complications such as faecal impaction. This condition occurs when a large and hard stool cannot be pushed out by a normal peristaltic and it blocks the rectum which gets enlarged, (Keshav,2004).The blockage could be accompanied with diarrhoea which is called overflow diarrhoea.

The diagram below shows the normal rectum and the enlarged rectum with blockage of faecal mass.

The treatment, even the symptoms of diarrhoea, must be with high doses of laxatives because the rectum needs to be cleared off from the faecal blockage to prevent further problems, (Keshav, 2004).

Acute constipation is unlikely to become chronic but it is very important to be aware how to prevent it by keeping a healthy diet including enough fibre and fluids (fruits, vegetables, cereals and wholemeal bread); be aware that some medication can cause constipation as a side effect, such as some strong painkillers (co-codamol or morphine), iron tablets or some antidepressants.

However some people have a healthy lifestyle, eat and drink enough fluids, do not have any disease or take any medication but they still suffer from constipation. This is very common in women.

Question 4 Section B

Diverticular disease is a possible result of constipation. Describe the signs/symptoms of this disease, and explain the underlying physiological changes.

Diverticular disease is very common and age is a predominating factor for this illness; it is proven that older people are more susceptible to diverticular disease. The disease can be divided into two groups: uncomplicated, also called diverticulosis, or complicated, which is known as diverticulitis,(Black and Hyde,2005).

Diverticular disease occurs when the lining of the bowel weakens over a period of many years and bulges, or pouches, known as diverticula, form. Having diverticula usually does not cause any symptoms. This is known as diverticulosis. If symptoms appear the condition is known as diverticular disease. In some occasions a complication happens and the diverticula become inflamed and cause diverticulitis,(Black and Hyde,2005).

The symptoms of diverticular disease usually start with abdominal pains in the lower large bowel, mostly on the left hand side. The patients can feel pain after eating food which passes away after being in the toilet. Other symptoms include bloating, wind, constipation or diarrhoea.

Diverticulosis usually causes only mild abdominal symptoms or discomfort which is not of any real concern for the sufferer. Patients tend to self-diagnose which can lead to an incorrect diagnosis and/or receiving wrong medication. Most of the patients are completely unaware that they have the disease until they have to do another investigation for a different occasion and the disease is diagnosed. When the diverticulosis is confirmed the patients need to follow a special diet, to increase their water intake (2L per day), analgesis and health advice from the doctors how to maintain a healthy bowel habit,(Black and Hyde,2005).

In some cases diverticulosis may become inflamed and to progress into acute diverticulitis. The patients with diverticulitis suffer inflammation and infection of the diverticulum.

The symptoms include severe abdominal pain, fever (high temperature), and nausea or vomiting, in some cases frequent urges to urinate accompanied by pain and changes in the patient's bowel habit. The blood vessel inside the diverticula may weaken which cause blood to appear in the faeces. If the blood is not from the lower part of the large intestine or it is from the digestive system (stomach) the faeces change their colour to black which makes it easy to distinguish,(Black and Hyde,2005).

Sometimes a scar tissue is made around the inflamed diverticula and the bowel becomes narrow or blocked.

If the diverticulitis is complicated the patients may suffer from abscess, blockage, fistula or mass. In most severe cases diverticula burst and cause the lining of the abdomen (peritoneum) to become inflamed as well. This condition is known as perforation with peritonitis which requires emergency surgery,(Black and Hyde,2005).

This is an image of the cross section of the large bowel showing the inner lining of the bowel bulging out through the weakened muscle wall. These bulges, or pouches, are the diverticula.