The following question was posed to the authors after they had presented the findings of their previous retrospective peristomal skin studies, which looked at pouches containing Manuka honey, at the 2019 conference of the European Council of Enterostomal Therapists (ECET): ‘Was any improvement in peristomal skin attributable to the benefits of convexity as opposed to the Manuka honey convexity flange?’ As clinicians, we felt obliged to investigate further. The primary focus of the study described in this article is therefore whether the use of a Manuka honey convexity flange improves peristomal skin integrity for patients experiencing sore skin, despite using other convex flanges. Patient assessment and evaluation was undertaken independently by patients’ stoma care nurses (SCNs).
An extensive literature search was undertaken to try to establish a consensus on the definition of the term ‘convexity’ and to further investigate the uses of convex flanges and pouching appliances; several seminal texts were identified and are discussed in the article. Convexity appliances are generally used to help in the management and/or prevention of complications, such as output from the stoma seeping under the appliance adhesive. These appliances are designed to place pressure on the skin surrounding the stoma, increasing its protrusion and improving the seal between the appliance and the patient's skin, thus reducing the risk of leakage.
Peristomal skin
Peristomal skin should have the same appearance as the rest of the abdominal area and should ideally remain intact and free from soreness. A number of factors can affect skin integrity, which can potentially result in broken skin and appliance leakage.
NHS Improvement (2017) studies suggest that a positive quality of life (QoL) can be achieved while living with a stoma. However, when there is a loss of skin integrity, this can lead to possible issues that will affect the adhesion of the stoma appliance, giving rise to leakage. This, in turn, will impact on the skin integrity and overall QoL.
Skin damage caused by effluent leakage
Effluent from a stoma that remains on peristomal skin for prolonged periods can impact greatly on skin integrity. Urine or faeces on the skin will result in skin damage, which is termed peristomal moisture-associated skin damage (P-MASD) (Burch, 2019). When peristomal skin is exposed to, and in contact with, urine and faecal matter, the balance of the skin's natural pH or acid mantle can be altered, resulting in the skin having a higher pH. This increases alkalinity, which can increase the risk of skin irritation, breakdown and infection (White and Evans, 2019).
The most common cause of sore skin is leakage of output from the stoma onto the skin (Burch, 2017). Skin breakdown may be the result of a poorly fitting stoma pouch. A number of ostomates will experience leakage from the stoma appliance, and many will endure the problem, as noted by Richbourg et al (2007), who estimated that upwards of 76% of stoma patients experience pouch leakage at some stage.
Quality of life
As well as the physical skin becoming damaged, painful and irritated, leakage from stoma pouches can have a significant effect on the psychological wellbeing of the patient (Cremen and Lee, 2016). Patient QoL has been widely studied in the context of living with a stoma. For example, Erwin-Toth et al (2012) suggested that leakage of effluent is deemed by stoma patients to be the key factor that negatively affects QoL. A patient's QoL can be significantly improved by managing issues such as appliance leakage and nurses have an important role in assisting patients to resolve issues such as those discussed by Burch (2014a) and Erwin-Toth et al (2012).
Specialist nurses who work alongside patients with long-term conditions, including individuals with a stoma, can significantly contribute to reducing unwarranted variations in the care delivered and by making clinical decisions relating to products for patients. In the NHS, the ongoing national programme, Getting It Right First Time, aims to support clinicians to do this (Carter, 2016; NHS Improvement, 2017).
Patient self-care and recognition of a peristomal skin complication
Complications resulting from a stoma can undermine a patient's ability to manage their care. These complications include: peristomal skin problems, ill-fitting appliances, stoma leakage, retraction/prolapse, parastomal hernia, and stomal bleeding. Further complications, such as blockages, bowel obstruction, high output stoma (ileostomy), dehydration and necrosis can prolong adaptation and potentially lead to repeated hospitalisation for treatment as reported by Lee and Morris (2003). Clinical discussions regarding the treatment of peristomal skin complications found that more than one in three visits to an SCN were related to such issues, resulting in significant costs for the NHS (Jemec and Nybaek, 2008).
According to Herlufsen et al (2006), around 40% of stoma patients may not recognise when they have a problem with peristomal skin irritation. In addition, they reported that 80% of those diagnosed with skin problems did not seek professional help. Thus, it is evident that not all patients recognise that they have skin problems, showing the need for periodic review of patients' peristomal skin by the SCN and greater patient education on what is ‘normal’ peristomal skin.
At first glance safeguarding may not seem directly linked to stoma care; however, we should not be complacent regarding the complications that can be associated with the use of convexity appliances, belts and support garments, which can sometimes cause harm and be attributable to ‘pressure’ on the skin. Many pressure-related incidents can be prevented with appropriate interventions and avoided through simple actions by staff, individuals and their carers by ensuring the selection of an appropriate device and educating patients on self-care (Department of Health and Social Care (DHSC), 2018).
Conditions that may require convexity
A patient may require a convex appliance when their stoma is retracted or flush to the peristomal skin. This can be a particular problem for people with an ileostomy or urostomy. Flush and retracted stomas can become apparent in the early postoperative period owing to surgical technique, obesity or poor stoma siting (Hanley, 2011). Retraction has been described by Cottam and Richards (2011) as any stoma that is less than 0.5 cm below the skin surface, and cases in which the stoma falls back into the abdominal cavity (McCahon, 1999). Cottam and Richards (2011) measured the heights of colostomies and ileostomies in millimetres within 48 hours of surgery and suggested that if a stoma is less than 10 mm in height within 48 hours of surgery, it has a 34% probability of becoming problematic.
Explaining convexity
Defining the term ‘convexity’ can be challenging. A review of the literature offers definitions such as being curved or rounded outward like a sphere. The term as defined by Hoeflok et al (2013a) has been used within ostomy care to describe the curvature of the skin barrier that is in direct contact with the peristomal skin. Further definitions have been offered by Burch (2011), Metcalf (2018) and Gardiner (2013), who suggested that the construction of the convex adhesive shoulders of the appliance enables pressure to be applied to the immediate peristomal skin, encouraging the stoma to protrude and thereby providing a tight, secure seal around the base of the appliance.
The emergence of softer convex products has challenged the conventional concept that convexity refers solely to rigid or firm products that apply pressure to the skin. For example, in 2001, Welland Medical (West Sussex, UK) introduced an integrated ‘soft’ convex product (Hoeflok et al, 2013a). Haughey and McGroggan (2017) have explained how the evolution of soft convex pouches has made nurses less hesitant to recommend them as a form of convexity. This has resulted in a steady rise in usage, with convexity products now representing more than 30% of the ostomy pouch market.
Why use convexity
The introduction of ostomy appliances using a convex base plate was considered by Cronin (2013). Convexity, according to Cronin, is effective in preventing leakage because it increases the protrusion of the stoma, thus facilitating efficient drainage of the effluent away from the skin and into the bag. Similarly, Hoeflok et al (2013b) stated that convexity serves a dual purpose: it exerts pressure on peristomal tissues, increasing resistance to leakage, while simultaneously enhancing stoma protrusion (height). The consequences of retraction are leakage and skin irritation, along with poor appliance adhesion (Kelly O'Flynn, 2018). In a subsequent article, Kelly O'Flynn (2019) explained that using convexity appliances helps reduce leaks from poorly spouted stomas because they exert pressure on the abdominal wall and enable the stoma to sit further into the pouch.
One of the key principles of ostomy care is to establish and maintain a secure and predictable seal, and convexity is often considered to be a tool in achieving this (Hoeflok et al, 2017).
The Nursing and Midwifery Council (NMC) (2018) Code and the RCN (2020) Principles of Nursing Practice promote patient safety and can determine the success and sustainability of patient safety initiatives.
Types of convex flanges
The authors of this article reviewed and adapted descriptive work undertaken by Hoeflok et al (2013a) and Buckle (2013), and simplified the terminology used to describe convexity (Figure 1). The purpose of the adaptation is to support clinicians to align convex terminology to the suitability of the available convex Manuka honey flange adhesive options, highlighted in orange in Figure 1. Clinicians can use the flowchart to determine the suitability of the patient's stoma for the Manuka honey flange options.
Depth
Hoeflok et al (2012) suggested that convexity should be described by depth and pressure. These descriptors vary between manufacturers and are included within the product information, they may be described as shallow, soft, medium, light, hard and firm. The authors have categorised the descriptors into three groups, namely shallow/soft, moderate and deep (Figure 1).
Flexibility
Hoeflok et al (2012) determined that the tension created by a convex product overrides the peristomal skin's ability to deform and enhances the ability to create an effective seal between skin barrier and peristomal skin.
Tension
The skin barrier needs to form a ‘mirror image’ of the peristomal plane, allowing for continuous contact between flange and peristomal skin, as discussed by Rolstad and Boarini (1996).
Flange properties
Most flanges are made from a hydrocolloid. This technology was enhanced in 2014, when a Manuka honey flange adhesive range was developed by Welland Medical Ltd. The benefits of Manuka honey on skin have been well established and widely reported (Evans, 2018), and the new range introduced medical grade Manuka honey into the hydrocolloid. According to Belcher (2013), medical grade honey has emerged as a product that can achieve a variety of outcomes and is safe and easy to use. Honey offers an alternative natural antibacterial to maintain the skin's protective layer when incontinence occurs.
The properties of Manuka honey were reviewed by Woodward (2019), who discussed the possibility that it could be beneficial in treating moisture-associated skin damage (MASD), including incontinence-associated dermatitis (IAD) and intertrigo dermatitis.
Assessing for convexity
The effective treatment and management of sore peristomal skin depends on the SCN completing a comprehensive assessment, including identifying the root causes and the extent of skin damage. Health professionals can find this challenging because some patients do not routinely contact them. Swan (2018) suggested that patients may persevere with ongoing stoma management problems, involving skin care and/or leakage from their appliance, because they perceive a certain level of problems to be normal and to be expected.
Familiarity with convexity products is generally gained through experiential learning. This was studied by Perrin (2016), who demonstrated that most SCNs learn how to use convexity through either personal experience or reflective study, and/or through discussion with colleagues, and/or from representatives of ostomy product companies.
Nurses skills and experience will vary, but assessment needs to include a review of the stoma and the peristomal skin by a clinical nurse specialist. This should include determining to what extent the stoma sits above (spouted) or below (retracted) the skin. Assessment may reveal that, although some patients have what would be considered by clinicians, ‘a normally spouted’ stoma, they still experience appliance leakage.
After a convexity product has been selected, it is important to undertake follow-up. Burch (2014b), Cronin (2013) and Hopkins (2015) have all recommended that peristomal skin should be inspected regularly to ensure that the convex flange does not cause damage. This can include bruising, worsening skin erosion and/or ulceration. These authors suggest that new ostomates are monitored every 2 weeks post discharge, or are taught to check the stoma themselves and highlight any concerns to their health professional in the first month following surgery and thereafter every 3–6 months, or at the discretion of the SCN depending on the need of the patient and their adaptation to life with a stoma.
Choosing convexity in practice
Stoma appliances come in a range of convex options, offering the possibility of a tailored solution for preventing and managing potential ostomy complications case by case. Burch (2019) emphasised that it is important for nurses to understand why, when and how convex appliances should be used; however, it can be difficult to decide which type of convexity is appropriate for an individual patient.
Once it has been established that a convex appliance is clinically appropriate, it is important to determine the type of convexity required. When selecting a convex pouching system, it is important to match the relative rigidity (tone) of the abdomen and the peristomal plane with the depth and rigidity of available products. It is also important to ensure that the aperture is correct for the stoma size. Choosing the most appropriate convex product is further complicated because, to date, there has been no national nursing guidance to define convexity exerted pressures.
A survey by Hanley (2013) found that three-quarters of SCNs would start with soft rather than deep convexity. However, there is evidence from manufacturing companies (Buckle, 2013) suggesting that light convexity—if used with a belt—may place the same or more pressure on the peristomal skin as deep convexity. Therefore, the aperture in the convex flange, the softness of the abdomen, the depth of the convexity and use of a belt all influence pressure and require consideration.
Study overview
A study was undertaken to determine whether the use of a convex flange with Manuka honey hydrocolloid adhesive would provide better results compared with using a convex flange without Manuka honey hydrocolloid. It was carried out with the explicit understanding that the findings would be published and with the permission to disclose data in anonymised format.
The multicentre study was undertaken across 21 NHS organisations in the UK and was conducted independently of the authors to remove potential for bias. To depict the involvement of the independent SCNs within this study, the reference SCNs* is used. Recruitment for the study was conducted by the SCNs* based on the clinical need of patient presenting and that the patient was already using a convex pouching system. Stoma care nurses saw patents routinely in their clinics and invited patients who they felt met the study criteria to participate.
The inclusion criteria for the study were patients, who were established users of convexity products and who were already wearing either a shallow/soft or moderate/light convex product. All study participants had visited their SCN* either due to regular review or because a problem had been identified.
Following assessment of the peristomal skin by the SCNs*, when they noted that the patient had peristomal skin complications, a change of pouch to the Manuka honey convex flange was suggested. The rationale for this was to support peristomal skin integrity because, despite using convex appliances, patients continued to have problems with their appliances. The depth of convexity offered by the Manuka honey pouch was similar to that of those being used by the patients up to the point of the study, thus reducing bias.
Findings
There were 31 patient data episodes from 31 patients (n=31) over a 6-month period.
Participant characteristics
Patients were mainly female (68%) (n=21) and the majority were aged over 51 years (73% n=23). Within the cohort, 74% had ileostomies, 16% had colostomies and 10% urostomies.
The time since stoma formation used within this study was classified as:
The main concern raised about the patients’ current convexity pouches was sore peristomal skin, secondary to leakage, which was reported by 74% of participants.
Stoma characteristics
The SCNs'* assessments recorded the patients' stomas as being:
Product choice
The SCNs'* assessment of patients' needs resulted in the selection of a one-piece convex appliance with Manuka honey for 97% of participants, with the remaining 3% trying a two-piece Manuka honey convex product. This is roughly in line with current usage of one- and two-piece products in UK clinical practice (NHS Business Services Authority, 2020).
Burch and Sica (2007) reported that the market in the UK has developed from one dominated by two-piece convex appliances to one where one-piece appliances predominate. England, Wales, and Scotland's stoma care pouch market continues to be led by one-piece products, with 91% of all pouches prescribed being one piece. The two-piece stoma pouches account for a modest 9% of pouch prescriptions (NHS Business Services Authority, 2020).
Product follow-up
Follow-up was guided by local policy and assessment of needs. Of the cohort, 45% (n=14) of patients were reviewed by their SCNs* within 2 weeks of introducing appliances with Manuka honey convexity flanges, as previously mentioned.
Patient outcomes
The study findings are presented in Table 1. The table shows the patient outcomes following use of the Manuka honey convex stoma products, along with supporting evidence on product security, leakages and increased product wear time.
| Independent study outcome | Supporting independent study data | Supporting evidence |
|---|---|---|
| Secure fit | Participating independent stoma care nurses (SCNs*) reported that 93% of patients had a more secure fit around their stoma, as defined by the reduced incidence of leakage episodes | Supported by Hoeflok et al (2017) discussion regarding alterations to the peristomal plane. Uneven skin surfaces, such as skin creases, folds, wrinkles or gullies, are frequently described as benefiting from the use of products with convexity. This is because the barrier protrusion can stabilise the plane and prevent leakage |
| Fewer leakages | SCNs* reported that 83% of patients experienced fewer leakage episodes | Turnbull (2003) and Perrin (2016) emphasised that a convex system must provide enough pressure around the stoma to create a good seal. It does this by applying pressure via the convex flange directly to the base of the stoma with enough force to make it protrude and/or adhere to the skin. In addition, the convex flange needs to be flexible enough to conform and seal to different tissue profiles during postural changes |
| Increased wear time | 55% of patients reported a longer wear time compared with their previous convex pouch |
Swan (2018) recommend that nurses ensure appropriate prescribing and effective use of appliances, which reduces waste and minimises the financial burden to the NHS, and improves QoL for patients |
| Reduced accessory usage | Patients reported a 16% reduction in the use of accessories (predominantly washer/seals) | As in this study, Hopkins (2015) documented that convex pouches help to manage retracted stomas. This is achieved by avoiding the use of seals and accessories, resulting in less complicated appliance changes for patients |
| Peristomal skin improvement patient assessment |
|
The outcomes of this study support the findings of previous work undertaken by the authors (White and Evans, 2019), showing the benefits that medical grade Manuka honey in a flange can provide to both patients and nurses when managing peristomal skin complications |
| Peristomal skin improvement SCN* assessment | SCNs* reported that in 90% of patients' peristomal skin had improved | The SCNs'* assessment of patient needs confirmed the recommendations made by Rolstad and Erwin-Toth (2004) and Rat et al (2018), namely that consideration of individual bodyshape, along with stoma contours, during product selection, can halt deterioration of peristomal skin |
| Patient needs met | 93% of patients reported an overall improvement following the use of the Manuka honey convex pouch and have continued to use the pouch as suggested by their SCN* | The findings of the study reinforce a statement by Black (2015) that the use of appropriate products can help ensure a better quality of life for stoma patients |
| Performance review of the convex pouch with medical grade Manuka honey hydrocolloid | 100% of SCNs* would recommend the convex pouch with a hydrocolloid flange containing medical grade Manuka honey to suitable patients | The confidence of the SCNs* in recommending convex pouches with a hydrocolloid flange containing medical grade Manuka honey confirms the statement made by Haughey and McGroggan (2017) that the evolution of soft convex pouches has made nurses less hesitant to recommend them |
In addition, the study findings showed that patients had less need to use accessory products. Furthermore, the study identified that, as a result of improved performance, the product met the patients' needs for the majority of the patients.
Verbatim comments from the SCNs* showed that the patients were satisfied with their use of the Manuka honey convex products:
Summary
Improving the quality and safety of health care is a system-wide priority. In times where the NHS is under substantial financial pressures to deliver efficiency savings, the Getting It Right First Time programme (NHS Improvement, 2017) has never been more important. It helps to reduce unwarranted variations in care and encourages improved clinical quality and efficiency.
When advising an individual, it is important to establish that the person has understood the advice and can put it into practice, has the necessary equipment and knows how to use it, and understands the implications of not following the advice (DHSC, 2018).
It should also be considered that providers of health and social care services aim to deliver personalised care that is safe, effective, caring, responsive and well led. Multidisciplinary teams often work together, within or across multiple provider organisations, to achieve this aim (Pearson, 2017)
The ideal outcome for patients with a stoma (Boyles, 2010) is that they reach the optimal level of rehabilitation and return to their normal day-to-day activities, while managing their stoma without disruption and excessive reliance on routine.
Conclusion
The study outcomes answered the question posed at the start of the article, namely: ‘Was any improvement in peristomal skin attributable to the benefits of convexity as opposed to the Manuka honey convexity flange?’. The patients and nurses were overwhelmingly more satisfied with the Manuka honey convex pouch than with their previous appliance.
The study also highlighted that, as clinicians, SCNs ensure that the needs of the patient remain at the centre of care. The findings further corroborate the wealth of evidence supporting the use of Manuka honey hydrocolloid flange adhesives, as evidenced by the improvement in peristomal skin complications identified independently by the SCNs* when the participants were using the convex pouch. Complications were deemed to have significantly reduced following the introduction of the Manuka honey convex pouch, as reported by both the SCNs* and the patients. Therefore, it can be concluded that medical grade Manuka honey can play a vital role within the improvement of peristomal skin complications.