SEM Scanner 200 for preventing pressure ulcers

SEM Scanner 200 can reduce pressure ulcer incidence but there are considerable uncertainties

4.1 The committee noted that the published evidence suggested that using SEM Scanner 200 would result in statistically significant reductions in pressure ulcer incidence. But clinical experts explained that the size of this benefit was greater than they would expect from their own clinical experience. One clinical expert commented that using SEM Scanner 200 had substantially reduced pressure ulcer incidence in their hospice, but not to the same degree as reported in the studies. The committee also considered that it was unclear from the studies whether a reduction in pressure ulcer incidence was due to the scanner results guiding care management decisions or the increased nursing care associated with using the scanner. It concluded that the evidence was unclear about how changes in clinical decisions making from using SEM scanner 200 lead to reductions in pressure ulcer incidence.

It is unclear how often the SEM scanner is used in clinical practice and how the results are used to change clinical practice

4.2 Clinical experts considered that SEM Scanner 200 provides information that could affect decisions about when to intensify preventive measures. These measures include improving the specification of the foam mattress, doing more regular repositioning of the patient, or other pressure-relieving measures. One clinical expert said that using SEM Scanner 200 allows nurses to intensify preventive measures earlier than when using clinical judgement alone. The committee acknowledged that using the SEM Scanner 200 may result in preventive measures being introduced or intensified earlier. The committee noted that there was no evidence to show the effect of earlier interventions on pressure ulcer incidence. It concluded that research is needed to assess the impact of introducing preventative measures earlier on pressure ulcer incidence.

There is uncertainty about the diagnostic accuracy of SEM Scanner 200

4.3 The committee heard from the company that SEM Scanner is not intended to diagnose pressure ulcers and diagnoses the increased risk of pressure ulcer development. The committee heard through correspondence with the Medicines and Healthcare products Regulatory Agency that the SEM Scanner 200 is used to identify patients at an increased clinical risk of pressure ulcers and should be seen as a diagnostic risk assessment tool.

4.4 The company acknowledged there is no appropriate reference standard for measuring subepidermal moisture and that this limited the assessment of diagnostic accuracy. Clinical experts also said using visual skin assessment as a reference standard would confound results because SEM scanner is designed to asses risk of pressure ulcer development before reddening whereas visual skin assessment records visible pressure injuries. The committee concluded that further research should be done to assess the use of SEM Scanner 200 without visual skin assessment for pressure ulcer risk assessment and that it should be compared with standard visual skin assessment.

The evidence does not address how SEM Scanner 200 performs across different populations

4.5 The clinical effectiveness of SEM Scanner 200 may vary between people with different comorbidities. Also, the clinical experts explained that part of the visual skin assessment is to identify redness, which may not be visible in people with dark skin. Using a non-visual method such as SEM Scanner 200 for these people may offer advantages and could address an unmet need. The committee also considered that the presence of comorbidities and conditions associated with skin damage or swelling may influence subepidermal moisture levels and affect the clinical accuracy of the SEM Scanner 200 to identify pressure ulcer risk. The committee concluded that further research should be done to assess the efficacy of the SEM Scanner 200 in preventing pressure ulcers for patients with dark skin and for those with comorbidities.

There is NHS interest in the SEM Scanner 200 because community and hospital-acquired pressure ulcers remain a significant problem

4.6 The NHS safety thermometer report states that from April 2014 to March 2015 approximately 25,000 patients developed new pressure ulcers. The national proportion of people with a stage 2 to 4 pressure ulcer in the UK is estimated to be 5%. The clinical experts explained that in view of the continued clinical challenges of preventing pressure ulcers in the community and in hospitals, there is increasing interest in using the SEM Scanner 200 across the NHS.

Using devices for measuring subepidermal moisture is referenced in global clinical practice guidelines

4.7 The committee noted the recently updated US National Pressure Ulcer Advisory Panel (NPUAP), European Pressure Ulcer Advisory Panel (EPUAP) and Pan Pacific Pressure Injury Alliance (PPPIA) global clinical practice guideline in the treatment and prevention of pressure ulcers. This states that healthcare professionals should consider using a subepidermal or oedema measurement device in addition to routine visual skin assessment to assess the clinical risk of pressure ulcers. The committee also noted that, based on evidence, the guideline only proposed a weak positive recommendation for these devices when assessing risk in people with dark skin.

SEM Scanner 200 provides an objective measure of pressure ulcer risk

4.8 SEM Scanner 200 provides an objective measure of variations in subepidermal moisture. Current risk assessment involves the combined use of validated scales and clinical judgement. The clinical experts explained that the availability of an accurate and objective measure of risk would be an advantage, particularly for training staff in pressure ulcer risk assessment.

The rationale for using SEM Scanner 200 needs further clinical testing

4.9 The company explained that the SEM Scanner 200 delta value reflects a measure of relative difference between the subepidermal moisture recorded over the bony prominences and surrounding tissues of the heels or sacrum. The greater the variation in subepidermal moisture (and therefore the delta value), the greater the likelihood of underlying localised inflammation. Although the committee accepted the rationale for this hypothesis, it considered that patients may have oedema from other causes and the principles need to be further tested in well-constructed clinical studies. It further noted that the interrater reliability of the device was reported by the company to be 83%. The committee concluded that further research would help to understand the reproducibility of the result.

SEM Scanner 200 needs cleaning between patients

4.10 The SEM Scanner 200 is classified as having a medium risk of cross-contamination. The company explained that cleaning is described in the information for use and has been shown to be effective in addressing the risk of cross-contamination. Clinical experts advised that cleansing wipes are used to clean the SEM Scanner 200 and this is in keeping with NHS infection and control procedures. The company stated that there have been no reported cross-contamination adverse events with the SEM Scanner 200.

SEM Scanner 200 has a battery life of 3 hours and a lifespan of over 3 years

4.11 The company explained that the SEM Scanner 200 has a 3-year warranty but the battery life of the device may be longer than 3 years. The clinical experts advised that 3-hour battery capacity is adequate because the SEM Scanner 200 is left on a charging station when not being used.

The company provides free training

4.12 The clinical experts explained that the company provides training in the use of the SEM Scanner 200. The device is easy to use, and the clinical experts described that staff became comfortable and familiar with its use within 2 weeks or so.

Uncertainties about the clinical benefit of SEM Scanner 200 results in uncertain cost-effectiveness

4.13 The committee noted that the key cost drivers, the reduction in pressure ulcer incidence and specificity of the device, were subject to considerable uncertainty. It concluded that more research was needed to establish the clinical and cost benefits of the SEM Scanner 200.

Further research is needed to address the uncertainty about the efficacy of SEM Scanner 200 in reducing pressure ulcer incidence

4.14 The committee concluded that further research was needed to address uncertainties about the efficacy of SEM Scanner 200 in reducing pressure ulcer incidence. This research should assess using the SEM Scanner 200 (without visual assessment) for assessing the risk of pressure ulcers compared with standard risk assessment using validated scales and skin assessment. Pressure ulcers occur in acute and community care so research should address the effect of adopting SEM Scanner 200 in each of these settings independently. Research should be sufficiently powered to include subgroups of people with dark skin and those with a range of comorbidities known to influence fluid levels in the subepidermis and underlying tissues. Clinical studies using the SEM Scanner 200 should be clear about how it affects clinical decision making; what effect it has on clinical outcomes and patient-related outcome measures; and the cost implications of its use.