The delivery of Safe, Effective, Harm Free care has been a focus for healthcare providers and regulators for many years.

Avoidable or preventable harms have a negative impact on the patient and the provider with potentially far-reaching consequences for both parties. See Table 1.

Table 1. Typical impacts/complications arising from preventable patient harm events.

One well-recognised, long standing patient harm is pressure related tissue injury (pressure ulceration). Pressure ulcers (PU) often act as a key indicator of care quality, and these preventable wounds consistently represent an important target for harm reduction by healthcare providers. 

Reductions in pressure ulcer incidence and/or targeted improvements to specific areas of PU prevention and management care bundles are often routinely reported metrics at monthly board meetings. These metrics typically offer senior management teams a way of tracking and measuring the impact of change on progress regarding patient safety and care quality within an organisation. 

Changing processes or products within a PU prevention and management care bundle can have a significant impact on reducing pressure ulcer harms. When adopting any new product into clinical practice, for example an innovative pressure area care (PAC) support surface, it is essential to ensure the product is fit for purpose, delivers the correct performance with regard to pressure redistribution, and meets patients’ clinical needs.



The primary aim of this service evaluation was to determine the impact of an innovative powered, PAC support surface (the OSKA Series5 mattress system) on the prevention and management of pressure ulcers for patients within a Critical Care Unit (CCU).  

The secondary objective of this work was to determine user views on the mattress system to ensure staff were satisfied with the products performance.



Within the twelve bedded CCU at Great Western Hospitals NHS Foundation Trust (GWH) four of the mattresses were replaced with the new OSKA Series5 lateral tilt mattress system (See Figure 1). The Series5 is a powered air mattress that offers alternating pressure or lateral tilt to achieve effective pressure redistribution under vulnerable patients. 

Figure 1. The OSKA Series5 lateral tilt mattress system

The mattress evaluation lasted four weeks, and the primary clinical outcome of interest was for patients placed on the Series5 mattress to remain free from any new areas of pressure related tissue injury.

The suitability / acceptability of the Series5 mattress for pressure ulcer prevention and management in this very-high risk patient population was assessed by structured questionnaires using Likert Scales, which were completed by CCU staff upon the conclusion of the evaluation period (see Table 2).



During the four-week evaluation a total of sixty patients passed through the CCU.  These presented with a range of primary diagnoses including trauma; cancer; surgical; spinal; stroke; cardiac and orthopaedic patients.

The four evaluation mattresses were used for a cumulative time of 112 CCU bed days and twenty patients were nursed on the mattress during this time.  All CCU patients placed onto the Series5 mattress were immobile, at very-high risk of pressure ulcers, fully dependent and unable to be repositioned, or with restricted repositioning due to their condition and/or the interventions they were receiving.

All twenty patients cared for on the Series5 mattress remained free

from any new pressure ulcers during their stay on CCU. Three patients placed on the mattress presented with existing pressure ulcers. These included pressure ulcers classified as ‘unstageable’ and ‘suspected deep tissue injury’. None of the wounds demonstrated any deterioration during the evaluation.

Nineteen staff completed a product feedback form and reported positive feedback on the mattress in terms of effectiveness, patient comfort and ease-of-use.

A further six CCU staff completed a more detailed post-evaluation follow up questionnaire. Staff stated that the product was suitable for pressure ulcer prevention for ‘very high risk’ patients and that the mattress was suitable for the management of patients with ‘all categories of pressure ulcer’. 

Product performance for PU prevention and management was rated as 8.5/10.

Patient safety (pressure ulcer harm prevention) when using the mattress was rated as 9.2/10.

The mattress system typically evaluated as ‘good’ or ‘excellent’ across a wide range of parameters. See Table 2 for a summary of the CCU staff feedback on mattress performance / acceptance.

Table 2. CCU staff feedback on the OSKA Series5 lateral tilt mattress.

In total, 87.5% of all responses rated the mattress as ‘excellent’ or ‘good’ across the twelve criteria covering clinical performance, product performance and user acceptance. 12.5% of responses reported ‘no view’, with none of the respondents reporting the mattress as ‘poor’ or ‘very poor’ for any of the twelve performance / acceptance criteria.



Effective pressure redistribution for CCU patients, that are often already classified as ‘very high risk’ of pressure ulcers, is typically compounded by the patient’s condition and their treatment in terms of medication or the requirement for additional lifesaving interventions. These additional complications will often limit both the ability of the patient to be repositioned and the frequency of any possible repositioning, thereby further complicating PU prevention strategies above and beyond those faced in the wider patient population. 

Delivering effective pressure area care in a complex clinical environment to one of the highest risk, most dependent patient cohorts within our healthcare system therefore presents CCU staff and Tissue Viability teams with one of their toughest challenges. 

When caring for such compromised and vulnerable patients, it is imperative that any PU prevention and management care bundle includes support surfaces that can deliver effective pressure redistribution whilst being simple to use and well-liked by staff. 

Whilst it is acknowledged that this work was limited in terms of number of support surfaces used and an evaluation period of four weeks, the real-world evidence presented above indicates that when used as part of a comprehensive prevention and management care bundle the OSKA Series5 lateral tilt mattress is effective for the prevention and management of pressure ulcers in CCU patients. The feedback from CCU staff on the mattress was also very positive across a wide range of performance and acceptance criteria, including patient comfort and ‘ease of use’.

The OSKA Series5 mattress is a step away from more traditional ‘alternating pressure air mattresses’ more typically used for the most dependent patients in CCU/ITU. However, it offers clinicians an innovative alternative support surface, suitable for pressure ulcer prevention and management, even in the most dependent patients. 



With pressure ulcers recognised as a key indicator of care quality and a target for harm reduction, the importance of reducing pressure ulcer incidence to the lowest possible levels is a clear focus for healthcare providers across all care sectors.

The CQC states that: 

‘Innovation is encouraged to achieve sustained improvements in safety and continual reductions in harm1.’ 

With this in mind, the Series5 mattress represents an innovative, highly effective alternative to more traditional air mattresses and may therefore be worthy of consideration when reviewing the provision of optimal pressure area care as part of pressure ulcer prevention and management care bundles.


  1. Care Quality Commission. Key lines of enquiry, prompts and ratings characteristics for healthcare services. Available from: Assessment framework for healthcare services showing changes from 2015 ( (Accessed 16 January 2023)