Evaluation of Repositioning in Pressure Ulcer Prevention

Abstract: Introduction: To reduce the risk for pressure ulcers, repositioning of immobile patients is an important standard nursing practice. However, knowledge on how this preventive intervention is carried out among elderly immobile patients is limited and to what extent patients perform minor movements between nursing staff-induced repositionings is largely unknown, but these movements might have implications for the repositioning intervention. Different lying positions are used in repositioning schedules, but there is lack of evidence to recommend specific positions.Aim: The overall aim of this thesis was to describe and evaluate how repositioning procedures work in practice in the care of elderly immobile patients. The aim was also to compare the effects of different positions with regard to interface pressure, skin temperature, and tissue blood flow in elderly patients lying on a pressure-redistribution mattress.Methods: This thesis consists of four quantitative studies. In Study I, 62 elderly immobile patients were included. All movements the patients made, either with help from the nursing staff or spontaneously, were registered continuously over the course of three days. Study II served to pilot the procedure for Study III. Tissue blood flow and skin temperature were measured in hospital patients (n = 20) for 5 minutes in two supine, two semi-Fowler, and two lateral positions. In Study III, a new sample was recruited (n = 25) from three nursing homes. Measurement of interface pressure was added, and the measurements were extended from 5 minutes to 1 hour. The six positions were reduced to four by excluding the two semi-Fowler positions. Blood flow was measured using photopletysmography (Study II-IV) and laser Doppler flowmetry (Studies III and IV). In Study IV a deeper analysis of the individual pressure-induced vasodilation (PIV) responses was performed on the sample from Study III. An age of 65 years or older was an inclusion criterion in all studies.Results: Study I showed that there was a large variation in the extent to which the elderly immobile patients made spontaneous movements, and these movements were positively related to taking analgesics and negatively related to taking psycholeptics. Patients scored as high risk for pressure ulcer development were repositioned more frequently than patients scored as low risk. However, the spontaneous movement frequency was not associated with any risk scores. Study II showed that the different lying positions influenced the blood flow in different ways. In Study III, it was found that the overall blood flow response during one hour of loading was significantly higher in the 30° supine tilt position than in the 0° supine, 30° lateral, and 90° lateral positions. The overall blood flow in the 90° lateral position did not differ compared to the 30° lateral position, although the interface pressure was significant higher in the 90° lateral position. In patients lacking a PIV response (Study IV), the blood flow decreased immediately and remained below baseline during the one hour of loading.Conclusions: Although elderly and immobilized, some patients frequently perform minor movements while others do not. Patients who cannot perform minor movements are important for the nursing staff to identify because they very likely need more intensive repositioning interventions. The spontaneous movement frequency was not associated with the risk assessment score, and this implies that some immobile patients assessed as low risk might need to be repositioned as often as patients assessed as high risk. Of the positions evaluated, the 30° supine tilt position was concluded to be most beneficial. There was no great difference in how the blood flow was affected in the 90° lateral position compared to the 30° lateral position, which question the appropriateness of the recommendation to avoid the 90° lateral position. The patients with lacking a PIV response might be particularly vulnerable to  pressure, which also implies that these patients might need to be repositioned more frequently.