How precise is the evaluation of chronic wounds by health care professionals?

Abstract

Chronic wounds are a growing challenge for physicians and health insurance agencies. The burden of affected patients is enormous, because of pain but also because of long‐lasting therapies and dependence on nursing services. In other areas of medicine, computer‐based diagnostics is established, yet, accurate wound documentation is rarely conducted and is often limited to size measurement with a ruler and a rough photo documentation. Objective assessment of lesions by evaluation of granulation tissue, fibrin coverage and necrosis is not performed. The aim of this study was to investigate the spread and variety in judgement of a chronic wound. A diabetic ulcer was described by 16 wound therapists (eight physicians and eight nurses). Granulation tissue, fibrin coverage, necrosis, size and depth of the lesion, wound exudate and wound edges were judged, and the therapeutical consequences were determined. Study data show an extensive inhomogeneity and a wide spread of the results, like in no other field of medical diagnostics. This could be shown in the group of physicians, as well as in the group of nursing personnel. As the choice of treatment by a specialist is based upon the assessment of the wound, it is possible that in practice it can lead to suboptimal therapy. This is a consequence of varying treating physicians and subsequent changes in treatment regimens. This results in a prolongation of treatment and burden for the patient. Circumstances like this contribute to rising of costs in this area of the health care system. The goal is to apply objective wound diagnostic technologies in the field of chronic wounds to catch up with other diagnostic procedures.

Introduction

The treatment of chronic wounds is one of the great challenges facing modern medicine. These wounds often occur as a consequence of diabetes, immobility, infection, or arterial or venous insufficiency. The number of patients in our society with injuries of this kind is increasing as a result of demographic change and the rising incidence of type II diabetes. These syndromes are therefore becoming an increasingly important factor for the health care system and health insurance agencies (1).

Patients with wounds of this kind, which often persist for years, are affected in many ways and experience a significant impairment of their quality of life 2, 3. Patients not only face pain: they often have to spend extended periods in hospital, undertake long and difficult journeys to see their doctor, wait for hours in outpatient departments, are dependent on nurses who visit them in their home, and experience aesthetically disappointing healing outcomes.

Another effect of this situation is the growing cost burden on health care systems. The increase in costs is caused by a number of factors: not only the costs of dressings and medication but also the costs of doctors’ and nurses’ wages, hospital admission costs and the costs of patient transport. Patients with chronic wounds are often ill for months or years, and so their labour is often lost to society. Taking the treatment costs caused by the diabetic foot syndrome together, we see that the financial burden amounts to 1 billion euros a year in Germany as a whole (4). Bedsores cost up to 2 billion euros a year in Germany alone (5). From this point of view, it would be desirable to reduce the length of treatment and thereby cut costs in treating chronic wounds.

Correct and appropriate treatment of chronic wounds depends on various factors: accurate assessment of the underlying condition and blood supply and also correct diagnosis. The condition of a chronic wound should be assessed on the basis of the following factors: the size and depth of the lesion, the presence of granulation tissue, fibrin debris, necrosis, wound exudate and the edge of the wound. However, in practice, wounds are often inadequately documented. Quite often, no record of the wound is kept at all. Size is assessed by drawing the wound on transparent film, counting calibrated fields or points or using a mechanical planimeter 6, 7, 8. But, measuring wound size with a ruler is often inaccurate as wound shapes are often complex. Photographic documentation of a lesion is a better method, but far too rare in practice.

Chronic wounds have three main tissue types: regenerative granulation tissue, fibrin debris and necrosis. These tissues are present in the wound in various colour spectrums. Granulation tissue is found mainly in the red spectrum. Its presence in a chronic wound indicates that regeneration is progressing well and that the wound is being properly treated. The presence of fibrin deposits, in the yellow spectrum, indicates the contrary situation. These deposits are found when a wound is deteriorating and bacterial activity is increasing. Necroses are usually black and of a dry or crusty consistency. Colliquation necroses are a subtype and are yellow in colour, similar to fibrin deposits. They are produced when necrotic tissue softens, and are therefore of a mushy consistency. The appearance of necroses indicates degenerative breakdown of wound tissue. As much as possible, this tissue should be removed in order to start the healing process.

Differentiating between these tissue types is essential for a correct assessment of the wound situation and for healing to progress normally. However, the size of the wound is not particularly relevant. We have noticed that wound size can change because of swelling of the lesion caused by oedema. This phenomenon may lead to misinterpretation of the wound situation. Progress of healing can only be monitored by objective evaluation of the principal tissue types.

Studies show that the human eye is unable to assess colour differences objectively. In a study, dermatologists familiar with the differentiation of skin colours were asked to assess the same schematic drawing of a venous ulcer in the homogeneous colours, red and black, twice within 6 months. An intrapersonal and interpersonal variability of up to 30% was observed (9). This means that subjective wound assessment consistently leads to wound status being reassessed and incorrectly evaluated because of the frequent changes in doctors treating the patient, thereby re‐examining the wound and producing inadequate, often purely descriptive documentation. This leads to frequent changes in treatment for the same wound, which fails to heal properly as a result. Little investigation has been carried out into the scatter pattern of chronic wound description by medical staff. We, therefore, carried out a study at our hospital to record the variability and accuracy of assessment of a chronic wound.

Methods

Eight doctors and eight nurses working at Vienna General Hospital for more than 2 years, dealing with chronic wounds as part of their everyday work, were asked to examine, describe and assess a patient with a diabetic ulcer during a regular visit on the ward. A ruler was used to measure the wound size. The participants were asked to give their opinion on the following parameters of relevance to the assessment of the wound status and associated therapeutic consequences. They were asked to describe whether or not necroses, fibrin deposits and granulation tissue were present at the wound site. The wound was documented using a standardised questionnaire, which was supplied to every participant where they needed to document certain aspects of the wound. They were asked to describe unusual features at the edge of the wound (reddening and the presence of wound exudate). Other assessment criteria included the size of the wound (horizontal and vertical diameter) and the depth of the lesion. The participants were also asked to indicate whether any exposed tendons were present and to give their opinion on the therapeutic consequences for the local situation as they assessed it for the frequency of regular dressing changes. The goal was to get an impression of the subjective assessment of chronic wounds by doctors and nurses. After the questioning, the ulcer was photographed using a standard digital camera (Coolpix 4500 Nikon, 4 million pixel) and the data was stored (Figure 1).

Figure 1.

A digital image of ulcer.

Results

All the participants completed the standardised questionnaire provided to them during the visit on the ward. The wound diameter as reported by the nurses and doctors varied between 3 and 7 cm. The depth reported by the doctors was 0·5 cm and between 0·6 and 2 cm by the nurses (Table 1). The exposed tendon was reported by 14 respondents and two respondents reported that no exposed tendon was present in the wound.

Table 1.

Summary of the wound assessment

	Size (cm)	Depth (cm)	Granulation tissue recognised	Fibrin recognised	Necrosis recognised
Doctors	3–5	0·5	2	7	2
Nurses	3–7	0·6–2	5	8	4

The main items missing in the wound documentation as filled out by the participants, related to necrosis and granulation. 62·5% and 50% of the respondents said that they did not know whether these features were present.

Half of those questioned said that they did not know whether granulation was present and 43% said that it was present (Table 2 and Figure 2, [link]). One respondent said that no granulation was present, and one person said that it was present at the edge of the wound. 93·8% of the participants said that fibrin was present in the wound and 6·3% (one individual) did not know. 37·5% of the participants said that necrosis were present in the wounds and 62·5% did not know (Table 2 and Figure 3, [link]).

Table 2.

Assessment results from eight nurses and eight physicians

Respondent	Necrosis	Fibrin	Granulation	Wound edge	Exudate
Nurse 1	No data	x	No data	Reddened	No data
Nurse 2	x	x	No data	Reddened	Mild
Nurse 3	No data	x	Wound edge	Bland	Mild
Nurse 4	No data	x	x	Reddened	Mild
Nurse 5	x	x	x	Bland	No exudate
Nurse 6	x	x	x	Bland	No exudate
Nurse 7	No data	x	No data	Reddened	No exudate
Nurse 8	x	x	x	Reddened	Mild
Physician 1	x	x	No data	Reddened	Mild
Physician 2	No data	x	No data	Reddened	Mild
Physician 3	No data	x	No data	Bland	Mild
Physician 4	No data	x	No data	Reddened	Mild
Physician 5	No data	No data	x	Bland	No exudate
Physician 6	x	x	No data	Bland	No data
Physician 7	No data	x	No data	Reddened	Mild
Physician 8	No data	x	x	Reddened	Mild

x, data entered.

Figure 2.

Frequency of responses on presence of granulation tissue.

Figure 3.

Frequency of responses on presence of necrosis.

There was considerable ‘disagreement’ regarding the edge of the wound. 62·5% described the wounds as reddened, while 37·5% considered them to be bland (Table 2 and Figure 4, [link]). 62·5% of the participants said that a moderate amount of exudate was present. 25% thought that none was present and 12·5% did not know (Table 2 and Figure 5, [link]). 87·5% of the participants thought that exposed tendons were present. 12·5% (two individuals) did not know (Table 2 and Figure 6, [link]). 43·8% assessed wound depth to be 1–2 cm. 37·5% made no comment on wound depth (Figure 7). 43·8% of the participants suggested that the dressings should be changed once a day. 37·5% were in favour of twice‐daily dressing changes (Table 2 and Figure 8, [link]).

Figure 4.

Frequency of responses on appearance of the wound edge.

Figure 5.

Frequency of responses on presence of exudate.

Figure 6.

Frequency of responses on presence of exposed tendon.

Figure 7.

Assessment of wound depth.

Figure 8.

Assessment of frequency of dressing changes necessary per day.

Discussion

The treatment of chronic wounds depends on an objective diagnosis, which is mainly based on the visual impression of the injury. So far, wound evaluation and proper record keeping hardly have been developed in clinical practice. Experience shows that records made by nurses are often better than those made by doctors. This is partly because doctors often assign treatment of chronic wounds to nursing staff. As a result, doctors often have little knowledge based on practical experience of modern chronic wound management methods.

The data collected during this study show a broad range in outcome of wound assessments within the participating group for the same ulcer. In our opinion, a statistical analysis is not feasible because of the fact that the participants only assessed a single wound. In addition, we feel that it is not necessary looking at the obvious differences in assessments between the participants. This applies to both the doctors and the nurses who took part in the study. These subjective assessments of the wound mean that there are almost as many assessments as participants. However, the reasons lie not only in the clear lack of knowledge in this area, but more in the fact that the participants were actually unable to recognise the tissue types present and to classify them correctly. To this end, an objective assessment of the various colours in the wound area is vital, as this determines the right therapy choice. With frequent changes in the treating physician because of, for example, changes in shifts, and is replacement by a colleague, either in an inpatient or an outpatient department, we find that treatments are often changed. This extends the overall length of treatment and increases costs.

Technical methods are needed to produce objective, reproducible findings in order to overcome the problem of inaccurate, subjective wound assessment. Such methods would also be helpful in assessing the progress of the wound, which is a very important element in what is often a long course of treatment. It is important that any system of this kind should be able to assess factors beyond accurate and objective measurement of wound size. Tissue evaluation is just as critical as determining the wound area, its overall size and vertical and horizontal diameter. The technology must be capable of differentiating between the principal tissue types (granulation tissue, fibrin deposits and necrosis) and determine how much of each type is present at the wound site. This will not only allow medical staff to determine the current state of the wound but also to monitor its progress by repeated assessments during the course of treatment, and so ascertain the success of the treatment method being used. Determining changes in principal tissue types (increase or decrease in the amount of granulation tissue, fibrin deposits and necrosis) will either show that the wound is healing or indicate that treatment needs to be adjusted. Comorbidities affecting wound healing, such as poorer blood supply, infection or inadequate nutrition, can also be detected.

In summary, we can conclude that the results of this study show the need for an objective wound assessment system. This is the only way in which the problem of untargeted attempts at treatment, frequent therapy changes and the resulting effects on patients and health insurance agencies can be properly addressed.