What are pressure sores? What are the common sites and how would you prevent development of these sores?

PAPER I DEC 2010
Q. What are pressure sores? What are the common sites and how would you prevent development of these sores?

Pressure Ulcers

Pressure sores, decubitus ulcers and bed sores are some of the different terms referring to the consequences of unrelenting pressure on vulnerable skin points. The commonest areas where they occur are the sacrum, heels and ischial tuberosities, and the greater trochanteric areas. The normal capillary pressure which has to be overcome to result in tissue ischaemia is 32 mmHg.12 This capillary pressure is easy to overcome over boney prominences. If one recalls the vascularity of the skin and subcutaneous fat...

Fig:The basic mechanism for the development of a pressure ulcer.

...it can be seen that an extensive plexus exists within the subcutaneous fat and the dermis. Thus although this pressure is overcome in everyday life, due to a good layer of subcutaneous fat and intact interconnections between the blood capillaries, true ischaemia of the tissue does not occur. In the conscious patient with normal sensibility and mobility, however, there will also be conscious and subconscious efforts at relieving the pressure from the vulnerable points. In contra-distinction, when there is poor nutrition, when the patient is unconscious, and when there is poor sensibility/mobility, tissue necrosis followed by local sepsis will results.Ultimately there will be loss of integument as well as loss of any underlying muscle with possible exposure of underlying bone/joints. A grading system exists to help in management plans for patients suffering from pressure ulcers. It is graded 1–4 as follows13:

(1) Non-blanchable erythema of the intact skin. This is a red or violaceous

area that does not blanch upon pressure with the finger, indicating blood

has escaped form the capillaries into the interstitial tissue.

(2) Partial-thickness skin loss.

(3) Full-thickness skin loss and extension into the subcutaneous fat.

(4) Extension into the muscle and bone. Prevention is far better than any attempts to cure these ulcers. It is incumbent on the attending surgeon to ensure appropriate nursing care such that pressure is relieved from the commonest points and the patient is turned regularly. The patient must be placed on an appropriate pressure relieving mattress. Malnourishment needs to be alleviated. If there is loss of continence of bowel or bladder then the effluent needs to be controlled either by diversion into reservoir bags (stoma, urinary catheterisation) or by regular cleaning. The development of pressure ulcers in otherwise normal surgical patients has been used by some as an indicator of the quality of medical care delivery.There has been a schema developed to assess the risk of pressure sore development in patients with the intention that resource allocation be rationally made to those most at risk. Independent risk factors are: general physical health, mental state, activity, mobility, incontinence and nutritional status. A common problem with the management of pressure ulcers is the lack of recognition of the problem when the ulcers develop. Typically a grade 4 ulcer carries significant morbidity. Lack of recognising the fact that the wound surface will have many deep fissures/sinuses means that they are inadequately treated and therefore recur rapidly. The apparent wound surface will only be a small portion of the true wound surface. This is explained by the fact that during their natural history, the skin and subcutaneous fat are destroyed, but the fat is destroyed to a greater extent than the skin and thus there will be some amount of undermining. Colonised or frankly infected ulcers will lead to further fat necrosis to differing depths surrounding the ulcer. Surgical management of pressure ulcers must be undertaken if the patient is acutely septic from an infected pressure ulcer and/or when the patient has been optimised for surgery. Again the principle of “tumour” excision of the wound has to be applied. Various aids have been developed to ensure complete wound excision. In essence all the aids to a comprehensive excision relate

to revealing the true extent of the wound surface. The so-called bursa of the wound needs to be excised. Thus sewing a gauze swab soaked in either betadine or hydrogen peroxide and India ink will delineate the bursa.Tumour excision can then be effectively undertaken by excising around this construct and ensuring that no pigmented tissue is seen. After a comprehensive excision one must remember that primary and reactionary haemorrhage is common and these must be anticipated during and after the surgery. In paraplegic patients, there is profound hypotension during anaesthesia and thus during wound excision cut blood vessels may be concealed and a reactionary bleed will occur post-op. When considering the reconstruction of pressure ulcers one must apply the KISS principle. A defensive approach will ensure that should the ulcer recur, options have not been exhausted. The usual reconstructive ladder/elevator/ toolbox can be applied in these cases. An algorithm is shown and the important aspect is to diagnose the condition accurately.

ref: surgical complications 2007