Humans in Science

Ha! I got you going. I don’t have any. Life is far from humdrum but I don’t feel like talking about it much.

Besides trying to remain logical and coherent with respect to certain situations at work, I am playing nurse twice a day – cleaning and dressing my daughter’s healing skin, as one of the operation sites is in an easily infected area. Here is what the student British Medical Journal has to say about the four phases of wound healing:

Haemostasis–Immediately after wounding, a platelet plug forms and blood vessels vasoconstrict. Later, a thrombus develops to seal the wound.

Inflammation–This occurs in the first two to three days after the injury, causing swelling of the wound edges. White blood cells remove necrotic tissue, and control infection.

(Let me tell you, the first time, we panicked after the first bandage change at postop +5 days, thinking that the white pus collecting around the suture sites was a sign of infection. But it gets worse).

Proliferation–Beginning on the second or third day after the injury, and lasting for two to four weeks, structure forming cells called fibroblasts proliferate into the wound, and produce structural proteins such as glycosaminoglycans, collagen, and elastin. New capillaries form at this time, and epithelial cells migrate across the top of the wound. Areas where this is occurring are known as “granulation tissue.”

(That’s where my girl is at today. The worst is the transition from inflammation to proliferation. I can pinpoint it this round to last Monday. The new capillaries pop when you so much as breathe on them, much less clean the material out from the parts of the wound where the stitches did not hold because they were under tension and caused local tissue death [dehiscence]. It doesn’t hurt so much as the earlier stages of healing, because the nerve endings have died back by now, but kids panic when they see blood [as do parents, although you can learn to deal]. So not only is it stressful but you have to smile and speak reassuringly and not make any sudden moves or get interrupted. And the open part of the wound is just awful to look at, much less clean out, when it’s the flesh of your flesh.)

Remodelling–After the proliferative phase subsides, the new capillaries atrophy and collagen changes from type III to type I and is rearranged so that it gives the best tensile strength. Myofibroblasts cause scar contracture. Strength of the wound increases to almost 80% of the original strength over this period of up to a year.

(She’s going back to school on Monday. So we’ll just have to make do. And I get a week of bed rest.)

 

Posted on Thursday, April 12th, 2007 at 6:59 am Categorized as:General

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