Friday, July 09, 1999

Pathophysogy week 2a

The inflammation process is our body's attempt to zero-in, confine, and repair damaged tissue cells cause by a pathogenic invasion that can occur when the body's first line of defense, the skin, has been broken. In other words, it is the body's natural means in restoring its homeostasis status after a tissue has been injured.
When an injury occurs, the insult stimulates the connective tissue cells (mast cells) and platelets to release chemical mediators such as histamine and heparin. This action causes the injured area blood vessels to dilate and become more permeable. The increase blood flow (hyperemia) to the injured region makes the area warm and reddened, while at the same time, diffusion (protein and fluid shift) of the blood plasma creates swelling in the injured region. The increase pressure from fluid and the chemicals released by the mast cells also activates the nerve endings, causing pain. In some cases, depending on injured area, a loss of function can occur because of the swelling and lack of nutrition to the area's cells. Leukocytes are rapidly attracted to the injured site by mears of chemotaxis,a chemical signal released by the injured cells. Phagocytes become the first line of cellular defense, moving out of the blood stream and interring the injured tissue by squeezing between adjacent cells in the capillary wall (diapedesis). Macrophages remove the cause and the debris (phagocytosis) in order for healing to take place. If the causative agent is not removed, inflammatory response will continue until it is. (Gould, B.E., pp 19 – 21, 22 – 23, 2011)
Richard, a 50 y/o father, fishing with his family in the bounty waters, started out his day with the joy in catching northern pike and days later, ended receiving antibiotics. The events that place cascade from one small mishap, a fish bite. Factors that allow the infection to spread prior to Richard's emergency visit will be pointed out the following narrative along with the answers to the remaining questions.

Richard's son caught a large northern pike. As the fish was brought in, it came off the hook and landed on the bottom of the canoe. Richard manage to subdue the fish and put it on the stringer, but in the process, the fish bit his finger. This caused a puncture and some bleeding at the base of the finger nail on the right ring finger. The wound was washed with boiled water and a Band-Aid applied which he wore for only one day until the bleeding stopped.
The moment the protective skin barrier was broken, the punctured wound ( fish bite) at the base of his finger nail provided a direct avenue for microorganism. Unknown to Richard, a tooth ( foreign body) from the northern pike was embedded in the puncture wound. The embedded tooth was full of germs, thus infection was inevitable. No antibacterial ointment was ever applied and the puncture wound was only Band Aided for one day (no mention of if Band-Aid was changed). The inflammation response was initiated when Richard was bitten by the fish.
Four days later, while at work, Richard noticed that he kept bumping the injured finger and that it was very sore. That evening, he ask his wife (an allied heath professional) about the soreness and she recommended washing it out again and applying a Band-Aid to protect it. The next night , 5 days after the injury, Richard came home and showed his wife his hand and arm. His wound was swollen and white with pus, and his arm now had red streaks to the shoulder. They immediately went to the emergency room and he was put on IV antibiotics. After two days of treatment, Richard was changing the bandage when he noticed a northern fish tooth had come out of the wound with the pus.
Even though the injured finger did not have protected covering from the environment, which it probably should have, the site was never iced, elevated, rested nor monitored for infection since day one and prior to evening on day four, when Richard ask his wife about the soreness. Richard's complaint of soreness in the the injured finger indicated that the inflammation was still in progress and infection had already begun due to the embedded northern pike's tooth (foreign body). Even if the northern pike's tooth was discovered a day or two earlier, contamination had already occurred with the fish's bite. The only possible advantage could be that the infection would be less evasive and Richard possibly only needed to be on oral antibiotics. Secondly, the wound was unprotected when Richard was at work, which may have provided more exposure to more microorganism, especially in his line of work.
Instead, on day five after the injury, Richard's wound was swollen and white with pus and his arm had red streaks to the shoulder. Pus is a purulent exudate that consist of collection of interstitial fluid formed in the inflamed area. Pus is usually thick in consistency, yellow-green in color, and contains leukocytes, cell debris, and microorganisms. Formation of pus found on Richards was a marker for a bacterial infection. The swollen and white wound indicated edema caused by the fluid shift in the interstitial space due to inflammation process. The red streaks found on Richard's arm indicated that the infection had begun to spread . Red streaks do not necessary mean sepsis however, it could eventually occult if immediate treatment was not taken. In Richard's case, the red streaking in the skin may possibly mean that the bacteria had spread into the lymphatic channels, causing lymphangitis; therefore, a excellent reason why Richard was put on IV antibacterial drug, a possible broad spectrum drug,in order to deliver a immediate loading dose and achieve an adequate blood level to effectively treat the infection. Along with help of IV antibacterial drug and the northern pike's tooth (causative agent) being expelled, Richard's injured finger can now start the healing process through skin regeneration. (Gould, B.E , pg 20,26,86, 2011)
The IV treatments were given on an outpatient basis. Richard spent 3 hours, twice a day for 3 days receiving antibiotics. An IV port was left in his arm and wrapped to protect it at work. However, when it was discovered he worked in the sewer system, he was instructed not to return to work until the infection was gone.
Richard already had one encounter with infection from the fish's bite, returning to work with the IV port, would have advance his risk for another infection. Working in a sewer system has to be a microorganism minefield.

Gould, B. E.. (2011) Chapter 2
(pp. 19-23), Path physiology for the Health Professions, 4th Edition. Saunders Learning, printed in United States.
Gould, B. E.. (2011) Chapter 2
(pp. 26), Path physiology for the Health Professions, 4th Edition. Saunders Learning, printed in United States.
Gould, B. E.. (2011) Chapter 4
(pp. 86), Path physiology for the Health Professions, 4th Edition. Saunders Learning, printed in United States.

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