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Friday, September 12, 2008

Anesthesia

One of the oldest forms of medical treatment is described in Genesis 2:18, 21-23, where the Creator Himself “caused a deep sleep” to come upon Adam while He took out the rib, closed up the incision, and made a “help meet for him.” Relief of pain is intimately associated with the rendering of needful medical care. This is one of the physician’s cardinal responsibilities.
For certain patients, some forms of severe pain may be life threatening. However, in the case of most effective pain relieving medications, addiction can occur, with distortion of mental imagery to the point of serious impairment. Thus, it is wise to look for the simplest methods of relieving pain when attempting to perform surgery.
Probably the oldest form of pain relief is refrigeration anesthesia. Extremities can be rendered pain free with ice packs. This is particularly valuable in the case of vascular disease where cardiac and circulatory impairment makes general anesthesia risky. During the World War II, army medics discovered that troops suffering from frostbite might save their limbs if the extremity remained frozen until medical care could be secured. This observation influenced all currently accepted first aid for frostbite used in our country.
In order to properly administer refrigeration anesthesia, the extremity needs to be cooled to the point of numbness, while keeping the remainder of the body warm to avoid a general drop in emperature, chilling, or agitation. Ice packs or snow can be used to progressively cool an xtremity, either a hand or foot. If the surgery is to be localized to the arm or leg, place the pack
just above the site of amputation. This reduces blood loss and allows for a careful, meticulous dissection of the tissue. Broken bones can be set with refrigeration. In the case of a simple fracture of the hand or wrist, immerse the extremity in ice water for one-half hour or more. This will allow manipulation and bone setting to be done quite painlessly.
Refrigeration can also be used topically in the removal of warts, moles, and other skin lesions. Dry ice or liquid nitrogen can be applied with a cotton applicator to freeze a small area and render it numb to pin prick.
A second method of anesthesia is the application of gradual pressure on a nerve. The ulnar nerve at the elbow (funny bone) is quite amenable to pressure. Quite often in certain positions a foot or a hand has been known to “go to sleep” due to stretching or pressure on an affected nerve. nowledge of neuroanatomy can utilize this principle favorably for surgery to an extremity.
Counterirritation can also be applied with electric stimulation near the point of incision. This can utilize DC current, but it is more effective with a pulsed generator, such as rehabilitation centers employ in treatment of chronic pain. Desensitization can be obtained with liniments and ointments, mustard packs or plasters. Even animal surgery has been performed using
counterirritation, e.g., the “twitch” on the nose of horses. Finally, it is helpful to understand some of the common injectable anesthetics that are used locally for the relief of pain. These are used both in dental and surgical care. But they have some side effects and potential allergic reactions. Injectable narcotics should always be avoided, as they leave behind serious effects on the brain. They are not only difficult to metabolize, but because of their tendency to produce euphoria can become rapidly addicting. On rare occasions for major procedures, general anesthesia may be necessary. The gaseous agent used in these cases should be that which is most rapidly metabolized and least toxic to the system. Nitrous oxide and oxygen are commonly employed together to relieve mild pain. Although ether is quite flammable, it still remains the safest form of general anesthesia, due to its rapid clearing from the blood by the way of the lungs and relatively low toxicity to the liver and other organs. Open drop techniques in a well ventilated area can be used, but for safety reasons general anesthesia ideally should be performed in a hospital. Newer anesthetic agents (Halothane, Ethrane, etc.), although more likely to cause toxicity, are less dangerous to the heart and usually nonflammable. Regional blocks, local nerve blocks, and spinal anesthesia have their places in hospital settings but it is beyond the scope of this book to detail their applications.

Thursday, September 11, 2008

Suturing

Considerable practice is required to suture incisions and lacerations quickly and accurately. Yet these skills are not beyond the reach of the average layman gifted with manual dexterity or an interest in mastering the art. If possible, practice your suturing techniques on a piece of sponge rubber, upholstery, or even a pillow. Some surgeons become skilled in knot tying, practicing on door handles or in the automobile while traveling. The accompanying diagrams, located on pages 178 to 189, help demonstrate the principles of the three basic methods of surgical knot tying. The one described as an “instrument tie” utilizes a hemostat or needle holder, while the others require only skillful fingers for proper use. I would suggest that a novice begin with the two-handed tie and instrument tie, adding more complex forms as skill is gained.
Avoid tying the sutures so tightly that insufficient blood flow to the skin edges results. This would cause delayed and incomplete healing of the wound.
“Approximate, don’t strangulate” is the watch word for closure of lacerations with sutures. Human bites, animal bites, and lacerations opened longer than 12 hours, or those grossly contaminated are not sutured, but allowed to granulate and heal by secondary intention.
The placement of sutures and selection of suture material will be described in the following sections, as the various types of lacerations and their special care are considered. In a home-like setting it is possible to make the appropriate needles, like bending a sewing needle, sharpening the point in a chisel fashion to better penetrate the skin. Silk or cotton can be boiled along with the needle, thus sterilizing it for use in suturing. Prepared packages, that come already sterile, are available from suture manufacturing companies and can be obtained in various sizes and needle styles. Remember to consult the suture use manual for aid in selecting the appropriate sutures.

Wednesday, September 10, 2008

Wound Care

There are three basic methods by which a wound heals itself. Primary Intention is the usual type of healing when an incision or laceration is closed immediately to allow close adherence of the opposing skin edges and subcutaneous layers. This permits healing from side to side with the east amount of scarring and pain. The rate of healing of our skin depends on its blood supply and the presence or absence of pressure, tension, and infection. The facial skin, with its rich blood supply, can heal in 3-5 days, while a thickened area of skin with less nutritive potential, such as the back or feet, may require two weeks or more. If sutures are placed, it is important to know how long healing will require to avoid too early removal and wound separation.
Secondary healing of a wound occurs when the laceration is too large to be closed or is infected and must be left open. A general principle of laceration treatment is this. A wound that has been open more than 8-12 hours is never sutured, since infection may already have developed. In uch case, granulation occurs with the formation of a specialized tissue across the wound, and later coverage with new skin. Some deformity and scarring usually occurs. Nevertheless, with the exception of very large ulcers, the skin healing is usually complete. Understandably, this akes longer. Proper care of the wound to prevent or treat infection will serve to hasten the healing process.
The third method involves the initial formation of granulation tissue, then a secondary closure of the wound with sutures. This accelerates the healing in large open lesions and is usually used hen a surgical wound, for some reason, separates and must be closed again. Even more scarring takes place as a rule, but the healing is usually complete.
Some essential factors in wound healing are the presence of adequate protein, vitamins, oxygen, and the prevention of infection. It is generally recognized that the normal rate of healing in a perfectly healthy patient is the optimum rate that can be obtained. Wounds do not heal as well in anemic patients. With a normal complement of white blood cells the healing of a sterile wound is not impaired. However, when infection is present delayed healing does occur. Swelling (edema), whether local or general, appears to interfere with the healing process. Older individuals take onger to heal than the young. Endocrine factors, such as the possible deficiency of thyroid or growth hormone, or adrenal dysfunction, may retard or interfere with the healing process.
Local factors are important. According to Van’t Hoff’s law, reactions occur more rapidly when the temperature is increased. Conversely, hypothermia will delay wound healing in most areas, lthough cold is sometimes used for pain control. The areas of the skin which have the best blood supply, such as the face and neck, normally heal the fastest. Fat persons tend to heal more slowly, and their wounds tend to separate more often than in people of normal weight. Skin utures are usually left in longer. Cleanly incised wounds will heal more rapidly than irregular jagged lacerations. The presence of a blood clot or hematoma may interfere with proper wound healing by preventing close contact of the walls of the wound, and thus there forms a pocket, called “dead space.” Infected fluids, pus, and foreign bodies will all retard the healing of these wounds. It is critical to cleanse the wound of all foreign debris, irrigating it thoroughly before any suturing is attempted. Suture material is also important in the care of wounds. Although stainless steel is the least reactive, it is difficult to handle and remove. The absorption of foreign material, such as gut, silk, cotton, and nylon will occur slowly, in the order that they are here
mentioned. Newer sutures of nylon, Dacron, and Teflon last longer and cause less reaction, but are not suitable everywhere. A suture use manual may be consulted to aid in selecting ppropriate materials. The suture manufacturer’s suggestion of needle size, type, and techniques should also be consulted.

Tuesday, September 9, 2008

Caries

Tooth decay (dental caries) starts with the destruction of the enamel cap by micro-organisms
present in the oral cavity and adherent to the tooth surface. This leads to exposure of the underlying dentin to the oral environment and to its destruction by bacterial proteolytic enzymes. The dental management is the way of teeth manage. Caries will not occur that somebody have a good dental management.
Enamel caries will not be visible in routinely prepared histologic sections as this tissue dissolves
completely during decalcification. In ground sections made from undecalcified teeth, microscopic
examination under transmitted light will reveal optical alterations related to decreased mineral content of a still-intact crystalline structure.
These alterations tend to occur over a coneshaped area having its base on the surface and its point towards the amelo-dentinal junction. With increasing loss of minerals from the enamel structure, this tissue will disintegrate. The dental consultant can make some suggestion about the caries.
Sometimes, this destroyed enamel will contain so much organic material that it is still present in decalcified sections where it is visible as a basophilic amorphous mass.
The initial carious lesion in dentin afflicts the tubuli that serve as a highway for bacteria to spread into the dentin. As the tubules of the carious dentin become more distended due to breakdown of their walls by the proteolytic enzymes excreted by the invading bacteria, they may fuse and form spindle-shaped cavities perpendicular to the tubules. Fusion of afflicted tubules over a longer distance may also create spindle-shaped cavities in the same direction as the tubuli run. Through the continued loss of dentin between the tubules, its inner structure crumbles away .
When caries is not halted by dental treatment, bacteria and their toxic products will reach the
soft inner part of the tooth, the dental pulp, and evoke an inflammatory response . Subsequently,
the pulp dies and toxic substances from the pulp space diffuse through the apical foramen into
the adjacent periapical part of the periodontal ligament and surrounding jaw bone. Periapical
disease will now ensue. If the root surface of a tooth is exposed due to periodontal disease, the root-covering caries may also be the victim of carious decay. At this site, the bacteria penetrate into the cementum using the collagen fibres that once anchored the tooth in its tooth socket as pathways. The dental consultants can make solution about it.

Antisepsis

One of the outstanding advances that medical science has made in the past hundred years is the establishment of antiseptic principles in the practice of surgery. Milestone discoveries were the germ theory by Pasteur and Koch, the emphasis on hand washing by Semmelweis, and the principles of antisepsis by Lister. To understand the relationship between infective agents and disease has allowed the art and science of surgery to develop many new techniques, as well as life-saving procedures.
Fundamentally, the principles of antisepsis deal not only with the presence or absence of germs, but also with the resistance of the person (host) to their invasion. The acid mantle of the skin and our body’s resident normal flora constitute an important barrier to the growth of disease-producing germs. Enzymatic protection by lysozyme in the nasal secretions, tears, saliva, and other mucous membranes affords a defense of marvelous significance and complexity.
From simple wound care to most complicated surgery, every individual should know how to avoid contamination by harmful germs. During the 19th century in Austria, Doctor Semmelweis began to encourage hand washing, requiring this of his residents after each post-mortem examination and before contact with maternity patients. The death rate from infection dropped
precipitously. Although this brilliant physician was persecuted by his own profession for these “strange” doctrines, decades later he was acclaimed a medical trailblazer. Without doubt, the washing of hands is as important to safe surgery, as the use of water internally is to fighting fever.
It is especially important to know how to wash the hands and prepare them to handle diseased or injured tissues. Usually before surgery, a soft disinfected bristle brush is used to scrub the hands starting first around each finger, the ends and sides of the fingernails, the palm and backside of the hand, the wrist, and then the forearm. To prepare for a delicate operation, ten minutes of this type of scrubbing is required, typically with an antibacterial soap. Sterile rubber or latex gloves should then be worn. Disinfectants such as organic iodine (Betadine), hexachlorophene (Phisohex), or other antibacterial soaps are used to prepare the patient’s skin for the incision. Where this is not available, soap and water are employed, however the scrubbing must be prolonged. It is well to remember, moreover, that the mere washing of the hands with any substance does not guarantee a totally germ-free skin.
Sweating is especially common under rubber or latex gloves, with the natural bacteria present in hair follicles and around the nails. Thus the bacterial count is only transiently suppressed, while our real line of defense is our body’ sresistance. Several routines and techniques of skin preparation will be described in the accompanying table.
In the treatment of skin wounds, copious irrigation with water is essential, With some force, the stream of water is directed at the contaminated areas. The wound is thereby cleansed, allowing germs, foreign debris, and blood clots to be washed away, making the area clean for closure or suturing. Preparation of the skin with appropriate antiseptics is also helpful. Proper nutrition to the injured area includes abundant oxygen and vitamin C to aid wound healing. Elimination of refined sugar assists in fighting infection. These measures, together with the avoidance of tobacco and other harmful substances that impair oxygen supply, will enable healing to occur rapidly.