- 1 - Welcome to the fourteenth edition of the Dressings Times which takes the form of a quiz which readers may wish to complete to test their knowledge of wound care matters. This quiz first appeared in the Community Outlook and is re- produced here with the kind permission of the editor of that publication. 1. A wound which is to heal by primary intention; i. Has the edges drawn together with sutures, clips or tapes [ ]. ii. Is covered with a dressing and allowed to heal by granulation [ ], iii. Is left exposed to the air to form a scab [ ], The correct answer is (i). Open wounds that are exposed to the air or covered with a dressing and allowed to heal by granulation and epithelialisation are said to heal by sec- ondary intention. 2. Most experts agree that for a wound to heal at the opti- mum rate it should be kept; Dry [ ], Moist [ ], Wet [ ]. It is now generally accepted that a moist wound heals more rapidly than a comparable wound that is kept dry. This is because epidermal (skin) cells can migrate faster across the surface of a moist wound than a dry one. 3. Which of the following cells are responsible for removing bacteria & debris from a wound? Macrophages [ ], Platelets [ ], Keratinocytes [ ], Fi- broblasts [ ], Erythrocytes [ ]. The correct answer is (i). Macrophages, together with poly- morphonucleocytes (neutrophils) produce proteinases and oth- er enzymes that break down clots and debris. They are also believed to produce factors that stimulate the formation of new vascular tissue and play a role in the control of fi- broblasts, (see below). 4. Which of the following cells are responsible for the pro- duction of granulation tissue ? Macrophages [ ], Platelets [ ], Keratinocytes [ ], Fi- broblasts [ ], Erythrocytes [ ]. The correct answer is (iv). Fibroblasts are responsible for the synthesis of collagen a major component of granulation tissue, (see below). 5. Which of the following cells are responsible for forming a new layer of epithelium (skin)? Macrophages [ ], Platelets [ ], Keratinocytes [ ], Fi- broblasts [ ], Erythrocytes [ ]. The correct answer is (iii). Keratinocytes, or epidermal cells, are produced in the basal layer of the epidermis. Normally these cells gradually migrate upward from this re- gion and become keratinised and flattened to form the stra- tum corneum, the outer layer of the skin. In the vicinity of a wound, however, the cells migrate sideways across the surface of defect to form a new layer of skin. 6. Granulation tissue consists principally of; i. A mass of red blood cells held together in chains [ ], ii. A collagen matrix containing protein and polysaccha- rides [ ], iii. A network of fibrinous tissue [ ], The correct answer is (ii). Granulation tissue consists of a complex mixture of proteins and polysaccharides which form a gel-like matrix contained within a fibrous collagen network. 7. Angiogenesis is; i. The formation of new blood vessels in a wound [ ], ii. The control of wound temperature [ ], iii. A mechanism for controlling wound pH [ ]. The correct answer is (i). 8. Collagen is a major structural compononent of the skin, It is composed of; i. A protein helix [ ], ii. A polysaccharide containing glucose and fructose [ ] iii. A complex mixture of polysaccharides and lipids [ ]. The correct answer is (i). Collagen consists of a mass of protein fibrils that are formed extra-cellularly from pre- cursors (building blocks) produced by fibroblasts. 9. A semipermeable dressing allows the passage of which of the following? Moisture vapour [ ], Water [ ], Gases [ ], Bacteria [ ]. A semipermeable dressing will permit the passage of moisture vapour and gases but will not allow water and bacteria to pass through it. 10. Which of the following types of dressings are generally considered to be semipermeable? Paraffin gauze [ ], Alginate sheets [ ], Hydrocolloid sheets [ ], Polyurethane films [ ], Activated charcoal dressings [ ]. Adhesive films made from polyurethane such as Opsite, Tega- derm, etc., are examples of semipermeable dressings. The outer backing layers of most, but not all, hydrocolloid dressings are similarly made from a semipermeable film, and therefore these dressings also can be described as `semiper- meable' when fully hydrated. The other products identified above are porous not semipermeable, i.e. they will permit the passage of liquid water and bacteria. 11. The process of removing dead tissue from a wound is called; Debridement [ ], Cautery [ ], Insufflation [ ], Exco- riation [ ], The correct answer is (i). 12. Which of the following vitamins plays an important role in the formation of collagen? Vitamin E [ ], Vitamin K [ ], Vitamin C [ ]. Vitamin C is an important co-factor in the formation of col- lagen, and a deficiency results in a reduction in wound strength. 13. Which of the following are required for protein synthe- sis? Zinc [ ], Vitamin B12 [ ], Iron [ ], Magnesium [ ], Copper [ ], All of the above are involved directly or indirectly in the production of collagen and other proteins. 14. Which of the following medicines may have an adverse ef- fect on wound healing? Corticosteroids [ ], Non-steroidal anti-inflammatory agents [ ], Antibiotics [ ], Cytotoxic agents [ ], Oral contaceptives [ ], Fat soluble vitamins [ ]. Corticosteroids inhibit the inflammatory response and the production of collagen and therefore will adversely affect the healing process. Non-steroidal anti-inflammatory agents (NSAIA) are often cited as having an adverse effect upon wound healing but results of clinical trials which prove this conclusively in human wounds are hard to find. The use of NSAIAs in patients with wounds therefore remains con- traversial. Cytotoxic agents, which interfere with mitosis, the process of cell division, can have a major adverse ef- fect upon the healing process. 15. Which of the following additional factors can have an effect on wound healing? Lack of sleep [ ], Stress [ ], Height [ ], Sex [ ], Age [ ], I.Q. [ ], Diet [ ]. Both lack of sleep and stress can adversely effect healing. It is also known that the rate of healing decreases with age. The most important factor, however, is an adequate diet without which healing may be seriously impaired. 16. Compression is a major factor in the successful manage- ment of which of the following types of leg ulcers? Venous [ ], Arterial [ ], Diabetic [ ], Traumatic [ ], Compression is a major factor in the successful treatment of ulcers which occur as a result of venous insufficiency, helping to prevent oedema and promote venous return. Com- pression is contra-indicated for diabetic or arterial ul- cers. 17. Before compression is applied it is important to deter- mine the ankle pressure index. This is obtained by measuring the blood pressure in the arm and foot and calculating the required ratio from which of the following; Arm systolic/foot systolic [ ], Foot systolic/arm systolic [ ], Arm diastolic/foot diastolic [ ], Foot diastolic/arm di- astolic [ ]. The correct formula is shown in (ii) above. 18. Below what value is the ankle pressure index generally considered to indicate the presence of ischaemia. 0.2 [ ], 0.4 [ ], 0.6 [ ], 0.8 [ ], 1.0 [ ], 1.2 [ ]. Most experts would agree that an index <0.8 is indicative of ischaemia and compression should be used with considerable caution in such patients. Except in exceptional circum- stances, compression should probably be avoided altogether in patients with an index of less than 0.7. Sometimes values as low as 0.3 are encountered, but the prognosis for such patients is very poor, and amputation is frequently neces- sary. 19. What ankle pressure is currently considered to be re- quired for the treatment of venous leg ulcers. <15 mmHg [ ], 15-25 mmHg [ ], 25-35 mmHg [ ], 35-40 mmHg [ ]. Medical opinion is divided, but there is a general accep- tance that for venous leg ulcers without an ischaemic compo- nent, an ankle pressure of 35-40 mmHg will provide the opti- mal conditions for healing. 20. When treating a cavity wound, should you; i. Pack it firmly with ribbon gauze [ ], ii. Cover the opening with an absorbent pad to contain the exudate [ ], iii. Leave it open to drain freely [ ], iv. Partially fill with a material that will absorb fluid and prevent an accumulation of exudate within the wound [ ]. Ideally, the management of cavity wounds should ensure that exudate and partially liquified necrotic tissue is removed or allowed to drain freely away. It is also important that the wound should be encouraged to heal from the base by the formation of granulation tissue and it should not be allowed to close externally until this has taken place. Lightly packing with ribbon gauze will achieve both aims, but the use of excessive amounts of material, introduced with con- siderable force into a narrow wound is likely to be counter- productive and may cause further damage. It is also possible that the loss of fibrous material or cellulosic particles from the gauze may retard healing. In recent years, large quantities of modern dressings such as pastes, gels and al- ginates have been used to pack wounds but although some pa- pers have been published to support the use these materials, further research is still required to prove their advantage over traditional techniques. 21. Can hydrocolloid dressings be applied to infected wounds? i. Yes, they are the dressings of choice for infected wounds [ ], ii. No, they are strictly contra-indicated [ ], iii. Manufacturer's recommendation vary and it depends upon the nature of the wound and the brand selected [ ]. Although a significant amount of evidence has been accumu- lated to suggest that hydrocolloids do not promote wound in- fection and may in fact help to eliminiate bacteria from wound in some instances, some manufacturers are not prepared to recommend that their products be used in this way. The correct answer is therefore (iii). 22. Which of the following groups of dressings are most likely to cause adverse skin reactions? Alginates [ ], Tulle dressings containing antibiotics [ ], Hydrogels [ ], Dressings containing iodine [ ], Dressings containing chlorhexidine [ ], Don't know. Both topical antibiotics and iodine can cause severe sensi- tivity reactions in some patients. No sensitivity reactions to alginate have been reported, and reactions to chlorhexi- dine are rare. 23. Under normal conditions, a donor site may be expected to heal within; 2-3 days [ ], 3-5 days [ ], 5-7 days [ ], 7-10 days [ ], 10-14 days [ ], 14-21 days [ ]. The healing rate of donor sites is partly determined by the nature of the dressings applied to them. Wounds dressed with `modern' dressings such as alginates, semipermeable films and hydrocolloids heal in about 7 days compared with 10-13 days for similar wounds dressed with paraffin gauze.