Classifications ( NIC ) validated for patients at risk of pressure ulcers 1

Objective: to validate the Nursing Intervention Classifications (NIC) for the diagnosis ‘Risk of Impaired Skin Integrity’ in patients at risk of pressure ulcers (PU). Method: the sample comprised 16 expert nurses. The data was collected with an instrument about the interventions and their definitions were scored on a Likert scale by the experts. The data was analyzed statistically, using the calculation of weighted averages (WA). The study was approved by the Research Ethics Committee (56/2010). Results: nine interventions were validated as ‘priority’ (WA ≥0.80), among them Prevention of PU (MP=0.92); 22 as ‘suggested’ (WA >0.50 and <0.80) and 20 were discarded (WA ≤0.50). Conclusions: the prevention of PU results from the implementation of specific interventions related to the risk factors for development of the lesion, with implications for nursing practice, teaching and research.


Introduction
The method which guides the nurse's clinical judgment and decision-making is termed the Nursing Process (NP), comprising stages of investigation (data collection), nursing diagnosis (ND), planning, implementation of nursing interventions and evaluation of the results presented by the patient, family or community as a result of the specific nursing practices (1) .
In the stages referent to the diagnosis, the intervention and the result, standardized terms described by the classification systems may be used, which point to the common phenomena in and for clinical nursing practice. Currently, the systems for classification of language which are most known and used in the Brazilian context are the NANDA-International taxonomies (NANDA-I) (2) , the Nursing Interventions Classification (NIC) (3) and the Nursing Outcomes Classification -NOC- (4) . These classifications promote the systematic communication and documentation of nursing actions, in addition to other benefits related to clinical practice (3) .
The care settings where the NP and classification systems may be applied are diverse, so some specific cases need to be better explored. One such case is the scenario of preventing pressure ulcers (PU), which demand concern from nurses and have been the object of discussion, principally in the hospital setting. The incidence of PU, however, remains high and these lesions are an important cause of morbidity-mortality, affecting the patients' quality of life, as well as creating costs for the health services (5) .
A PU is a lesion of the skin and/or the underlying tissue, generally over a boney prominence, due to pressure which may be combined with shearing and/ or friction (5) . The following stand out among the risk factors which contribute to patients' exposure to the development of PU: deficit in mobility and/or sensitivity, friction and shearing, edema, humidity, advanced age, systemic illnesses, use of certain medications such as corticoids, anti-inflammatories and antibiotics, nutritional deficiency, neurological compromise and metabolic disorders (5) .
The early and regular risk stratification for the development of PU, which may be accomplished through the use of scales such as the Braden scale, supports the adoption of preventive measures for reducing the factors which predispose to tissue hypoperfusion, the optimizing of the individual's general and nutritional status, and the promotion of localized care to the skin (6) .
This evaluation can also support the establishment of an accurate ND, which is a basis for the selection of nursing interventions for each patient, taking into account the anticipated results (3) .
Currently, the diagnosis (NANDA-I) which best translates the situation of vulnerability to PU is the 'Risk for Impaired Skin Integrity' (00047), found in Domain 11, Safety/protection, in class 2 of Physical injury. So that this ND may be identified with greater accuracy, NANDA-I recommends the use of a standardized risk evaluation instrument (2) , such as, for example, the Braden Scale, which evaluates an individual's risk of PU. However, the ND in question is not specifically for determining the risk of PU, but rather any risk to the skin's integrity.
Although the NIC presents various possibilities for interventions for this ND, there are no validation studies in the care setting for patients at risk of PU. A recent search in a database using the terms "nursing interventions classification and validation study" found 35 publications (7) , of which four were Brazilian. None In the NIC's linkages with NANDA-I, 48 nursing interventions for the ND of Risk for Impaired Skin Integrity are presented, of which three are 'priority', 28 'suggested', and a further 17 'optional' (8) . The 'priority' interventions are those most likely to resolve the problem. The 'suggested' interventions have a high probability of resolving the ND and the 'additional optional' interventions are those which apply only to some of the patients with the ND. In addition to these 48 interventions, in the book 'NOC and NIC linkages to NANDA-I', the existence was ascertained of other nursing interventions, for the ND of Risk for Impaired Skin Integrity (9) .  4= considerably used and 5= highly used. Guidance on how to fill out and return the instrument was sent to the participants along with the instrument.
Data analysis was undertaken statistically, taking into account the marks given by the experts for each intervention (11) . The marks' weighted averages were calculated, with the following weights being attributed (11)

Results
The sample was comprised of 16 expert nurses, who had graduated on average 104.5 (14 -320) months previously and who had participated in study groups on skin and wounds for an average of 33.5 (12 -144) months. Seven (43.75%) of the experts held the title  Table 1.  (12)(13)(14) .

The interventions Skin Care: topical treatments and
Positioning, validated in the present study as 'priority', are presented as 'suggested' in the NIC-NANDA-I linkage. It is emphasized that the use of products applied topically can alter or maintain the integrity of the skin and that currently there are various products for this, aimed at avoiding the development of PU (15)(16) .
They require, however, constant assessment on the part of nursing (17)(18) .
PU can originate from inadequate positioning of the patient and/or remaining in the same position for a long time, which causes pressure on particular areas of the body. This requires intervention in the form of (re-) positioning one or more areas of the body in contact with a hard surface, such as the mattress and/or chair, as the frequent mobilization of the patient is a means of avoiding, reducing and/or controlling the occurrence of PU (16) . The changes in the patient's position, whether in bed or the chair, and the use of equipment adapted to relieve pressure, are essential in the prevention of PU, as they help interrupt the process of local cellular hypoxia, which interferes directly in the appearance of the lesion (17)(18) .

The interventions Bathing, Vital signs monitoring and
Nutrition management were also validated as 'priority' in the present study. They are, however, considered additional optional interventions in the NIC-NANDA-I *Nursing interventions also described in the NIC as 'suggested' by the linkage NIC-NANDA-I.
Twenty interventions were discarded in the study, with a weighted average of ≤ 0.50 (Table 3).  linkage for the ND Risk for Impaired Skin Integrity. The intervention Bathing includes skin hygiene, which must be clean, without moisture, and sufficiently hydrated to reduce the risk of PU and invasion of pathogens (18)(19) .
In addition to this, in the case of bathing, the nurses can supervise the condition of skin integrity and provide relief from the sources of pressure, stimulating the circulation and repositioning the patient.
The importance of Vital signs monitoring in the evaluation of the circulatory condition and the skin temperature is also recognized, as it can support the nurse in making a risk diagnosis such as the one studied. Similarly, the evaluation of these patients' nutritional status is important, as it determines the need for the validated intervention of Nutrition management, to maintain the organism with an adequate nutritional intake and thus facilitate its capacity to maintain skin integrity, in addition to promoting its regeneration and the process of healing (16,20) .

The intervention Urinary elimination management,
presented as an additional optional intervention for the ND Risk for Impaired Skin Integrity in the book 'NOC and NIC linkages to NANDA-I' (9) , was also validated as 'priority'. It is known that one of the determinants for PU is skin moisture, a condition which makes it more fragile and susceptible to friction and maceration. Moisture, whether from products or from physiological secretions or fluids, causes softening and maceration of the skin, with a reduction in its tensile strength, rendering it weaker to compression, friction and shear, in addition to fostering an increase in the growth of micro-organisms which impair its integrity (20) .  (12)(13)20) .
The number of nursing interventions validated as 'priority' in the care of patients at risk of PU (nine) was greater than that presented at this level in the chapter on linkages of NIC interventions with the ND of Risk for Impaired Skin Integrity. These results strengthen the specificity of care for this clinical situation, which -on its own -indicates the need for a specific ND which could be termed Risk of Pressure Ulcer (22) . taking into account the specificity of the care for the patient at risk of PU, may also help in establishing the risk of the same with greater discernment, as well as helping in its prevention and treatment (24) .

Bavaresco T, Lucena AF.
Thus, it is understood that the study's results advance knowledge of the NANDA-I and NIC classifications -principally of the latter, which present interventions which foster communication, the recording and the implementation of continuous and systematic nursing actions.

Conclusions
It is concluded that, of the 51 interventions