Pressure injury prevention in the perioperative setting: An Pressure injury prevention in the perioperative setting: An integrative review

Background: Pressure injury (PI) has a significant impact on patients and their families, and is costly to health care institutions. Perioperative PI remains problematic, although little is reported about current perioperative pressure injury prevention (PIP) strategies. Aim: To identify the key perioperative PIP strategies, following a systematic review of published research, to describe existing gaps in the literature, and to inform the development of subsequent observational study. Design: An integrative literature review method developed by Whittemore and Knafl 1 was used. Method: Research inclusion and exclusion criteria were identified a priori. Six data bases were searched and search terms included pressure ulcer/sore prevention, perioperative, operating room. Two review authors evaluated the quality of the studies using a validated tool, and a third author arbitrated when there was a discrepancy. Agreement between the two rates was measured using an intraclass correlation coefficient (ICC). Findings: Based on the inclusion and exclusion criteria, 270 papers were screened and ten quantitative studies were included. Quality scores ranged from 29 per cent to 89 per cent, resulting in an ICC of 0.955 (95 per cent confidence interval, 0.821 to 0.989, p < 0.0001). Five key PIP strategies were identified, including skin inspection, support surfaces and positioning aids, thermoregulation, medical devices and/or equipment, and interprofessional communication. Conclusions: This review confirmed the scarcity of current evidence of perioperative PIP practice and identified five key perioperative PIP strategies. Most of the reviewed studies focused on one main PIP strategy, and no direct observational studies have been undertaken in relation to perioperative PIP.


Background
Pressure injury (PI) is defined as an injury on or underneath the skin that can occur in less than one hour under certain constant pressures [2][3][4] .If constant pressure is greater than 32 mmHg, it will result in an occlusion of blood flow, which may ultimately affect the skin, soft tissue, muscle and bone, and lead to the development of localised ischemia, tissue inflammation, tissue anoxia and necrosis 5 .PI is recognised as one of the most costly and complicated conditions 6 .PI can have devastating effects on personal and social life of patients and their families, and impose heavy financial burdens on health care institutions.While hospitalised patients with restricted mobility have increased risk of developing PI, anaesthetised patients undergoing surgery are at even greater risk 7 .However, little is Peer-reviewed article known about the strategies that are used during anaesthesia and surgery to minimise this group's risk of developing a PI in the post-operative period.
Despite international guidelines 8 and a growing evidence base for pressure injury prevention (PIP), surgical patients are at high risk of developing hospital acquired pressure injury (HAPI) 9 .It is imperative to understand current perioperative PIP practice compliance with the relevant guidelines.To address this issue, we undertook a comprehensive literature review in relation to perioperative PIP practice.

Aim
The objectives of this integrative literature review were twofold: • to identify the key PIP strategies used in perioperative settings, based on assessment of published research related to current perioperative PIP practice • to identify the existing gaps in the literature to inform the development of a subsequent observational study.

Methods Design
This review used an integrative review design, based on a systematic and comprehensive approach.An integrative review can incorporate various study methodologies and subsequently has the potential to capture a broad range of issues relative to the status of current perioperative PIP practice, as reported in research literature.
A widely accepted framework developed by Whittemore and Knafl 1 guided the development of this review across five stages: problem identification, literature searches, data evaluation, data integration and results presentation.

Literature search methods
The databases used to search the literature included Cumulative Index to Nursing and Allied Health Literature (CINAHL, via EBSCOhost), Medline (via EBSCOhost), PubMed, ProQuest Central, Cochrane Central, Web of Science and Scopus.The Google Scholar database does not have similar Boolean operator functions; thus, it was only used to retrieve information when the full text of an article was not found.Reference lists of selected journal articles were also reviewed, as well as articles recommended by the research student's supervisors.The following combinations of keywords, categorised into three groups, were used as search terms: • health care issues: 'pressure injury', 'pressure ulcer', 'bedsore', 'bed sore' • health care location/stages: 'operating room', 'operating theatre', 'surgery', 'perioperative', 'intraoperative', 'preoperative', 'post-operative' • study core focus: 'pressure injury prevention', 'pressure ulcer prevention', 'pressure injury prevention practice', 'pressure ulcer prevention practice', 'skin inspection', 'positioning aids', 'support surface', 'thermoregulation', 'thermal regulation', 'pre-warming', 'medical device', 'medical equipment', 'communication'.

Inclusion and exclusion criteria
The inclusion and exclusion criteria were based on the review's aims, and thus focused on articles that were relevant to perioperative PIP practice.
The following inclusion and exclusion criteria were applied.

Inclusion criteria:
• primary research articles, using either quantitative or qualitative methods • quality improvement studies, • abstract and full text available in English • published from 2006 to 2017 • perioperative settings with adult inpatients.
Exclusion criteria: • the topic's interest was not directly related to or did not describe PIP in the perioperative setting • the study was conducted in ambulatory settings where patients were discharged on the day of surgery • simulation studies conducted in perioperative settings.

Data extraction
Guided by research aims and the inclusion and exclusion criteria, the titles and abstracts of all searched articles were first reviewed by the research student for data extraction.Data were extracted and synthesised according to author, year, country, aim/design, sampling/measures, key findings, and limitations.One of the student's co-supervisors then independently screened the titles and abstracts against the inclusion and exclusion criteria.Where there was a difference of opinion, the other co-supervisor reassessed the articles to make a final decision.

Data evaluation
Following data extraction, the selected studies were critically assessed using a quantitative checklist, as described by Pluye, Gagnon, Griffiths, and Johnson-Lafleur 10 .This checklist, known as the Mixed Studies Review, provided quality scores using 14 assessment criteria (based on quantitative methods).In each criterion, the scores ranged from 0 to 2, where 0 = 'no', 1 = 'partial', 2 = 'yes' and 'NA' = 'not applicable'.A final score was calculated for each article as a percentage indicating the proportion of items applicable to each study.Agreement between raters was measured using the intraclass correlation coefficient (ICC).A coefficient of ≥0.70 was considered acceptable for internal consistency 11 .Similar to the data extraction process, the quality assessment of the selected articles was independently appraised by the research student first, then by the student's cosupervisor.

Data synthesis
The included studies were analysed using a qualitative approach to categorise the key PIP strategies.The research student independently read, and re-read each article to identify commonalities and differences in study methods and PIP strategies used across perioperative settings in the included studies.This process was iterative and regular meetings with the student's research supervisors were held to clarify and discuss categorised findings.

Results
The results of this integrative review indicate the scarcity of published research on the status of current PIP practice in perioperative settings.All of the included studies were quantitative.Most of the included studies focused mainly on one PIP strategy, and used an interventional approach to examine health professionals' knowledge and practice, or assessed the effect of support surfaces and positioning aids, thermoregulation or medical devices and/or equipment on reducing the incidence of PI.None of the included studies used direct observation.

Descriptive findings
The first search identified 284 articles from seven databases and other resources, as reported in Table 1.
Medline and Scopus provided the bulk of the literature based on the search criteria.
Of the 270 articles initially identified, a total of 82 duplicates were removed.

Data presentation
The ten primary studies included in this review were selected according to the inclusion and exclusion criteria.Abbreviations: OR = operating room, PACU = Post Anaesthesia Care Unit, PI = pressure injury, PIP = pressure injury prevention, SAPU = surgical acquired pressure ulcer.
Three included articles examined support surfaces 12,14,17 , and two of these used randomised controlled trial approaches 14,17 .In this review, operating table mattresses (i.e.foam, gel or water-filled mattresses), various overlays on the mattress (i.e.air, water, gel, foam or a combination of these), and positioning aids (i.e.arm board, facial pillow, pillow, gel pad or heel pad) were used for different surgical positions.However, the effectiveness of these support surfaces and positioning aids varied [12][13][14][17][18][19][20] . In the iterature, using higher specification foam mattress and/or overlays in the operating room rather than the standard hospital foam mattress to prevent or reduce the incidence of intraoperative PI is recommended 8,21,22 .However, increased incidence of developing PI was reported when support surfaces were in use with other positioning aids or warming devices, for example, the combined use of warming devices and two-inch foam or gel mattress 13 , or the use of gel mattress 18 , or the use of foam overlays on water-filled warming mattress 17 .
Apart from support surfaces, various positioning aids are used for surgical positioning to avoid potential tissue injury, as patients' weight cannot be evenly distributed on the operating table in certain surgical positions 19 , for example, using facial positioners/ pillows to reduce interface pressure at patients' forehead and chin in the prone position during spinal surgery 8,14 , using heel support in prone position on the operating table 8 , or using pillows, blankets, gel pads and foam pads to reduce interface pressure intra-operatively 13 .However, one study reported the use of sheets and blankets to position patients decreased the effectiveness of support surfaces and caused additional interface pressure 23 .
Four included articles focused on risk factors and/or incidence of PI 9,13,18,19 , for example, using warming devices in the preoperative to postoperative phases, an important thermoregulation strategy, to prevent post-operative hypothermia and PI 7,24-

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. The commonly referred to warming devices in this review were limited to the Bair Hugger™, warmed blankets and operating bed mattresses 9,13,17 .However, using the warming devices combined with certain support surfaces increased the risk of PI development 13,17 .These results reflect other findings reported in the literature relative to the association of tissue damage and increased skin temperature, where pressure and time remained constant 3,[29][30][31] .More recently, Yoshimura et al. 9 suggested hyperthermia was independently related to intra-operative development of PI when the length of surgery was over six hours.
One included article focused on educational interventions to improve perioperative health professionals' PIP practice, including communication and the use of positioning aids 20 .Effective interprofessional communication, such as routine documentation, is an important PIP strategy 19 .Sutherland-Fraser et al. 20 and Sewchuk et al. 12 suggested all members of perioperative teams, rather than members of just a single discipline, e.g.nursing, should collectively be involved in communication around PIP.This recommendation is echoed in the broader literature 8,32,33 .However, there are barriers to effective communication in surgery, including inadequate verbal handover and documentation 20,34 .In two of the review studies, improvements were noted in verbal communication and documentation following an educational intervention 12 , and in post-operative PI incidence 16 .
One included article focused on the use of medical devices to prevent intraoperative HAPI 15 .The use of medical devices and/or equipment related to PI accounted for approximately 50 per cent of HAPI development, similar to what has been reported elsewhere 35 .Those patients with a medical device were 2.4 times more likely to develop a PI in an atypical place 36 and later during their hospital admission 37 .PI related to medical devices is more likely to occur in certain locations in the body, such as the head, face, neck and ears, which are areas characterised by less subcutaneous tissue, for which PI progression can be rapid 38 .Therefore, the location of PI is one of the significant indicators that differentiates PI related to medical devices from PI not related to medical devices in the operating room.
In this review, Nilsson 19 reported no association between the number of monitoring devices on the patients' arms and the development of PI.However, Goodwin et al. 15 found that using a Mayfield clamp to position patients' head in jackknife surgical position potentially prevented the development of PI.Further, no other reviewed studies examined medical devices and/or equipment use in relation to PIP.As Apold and Rydrycb 13 suggested, there is a lack of consensus on best practice for the inspection and management of skin around medical devices in relation to intervals for repositioning devices that can be removed for pressure relief purposes and processes for replacing ill-fitting devices.
Minnich et al 16 focused on perioperative skin inspection for PIP purposes.Skin inspection, an essential perioperative PIP assessment, was not the focus but has been mentioned in other reviewed studies 12,20,21 .Skin inspection was compromised because of nonadherence to the clinical practice guidelines.This was related to staff's inadequate knowledge of using the guidelines, negative attitudes towards PIP because of lack of time or nursing staff, lack of awareness of PIP or involvement of practitioners at all levels, as identified in the reviewed studies and the broader literature 12,20,34,[39][40][41][42][43] .In this review, frequent skin inspection as a PIP strategy has been recommended, especially during the intra-operative phase when the patient is positioned according to the surgical procedure, and at each perioperative stage 16,19,20 .Two studies found increased use of skin assessment tools in relation to perioperative PIP following educational interventions 12,20 .
Post-operative PI incidence was measured in most included studies (nine out of ten) at different time points, from immediately following a procedure until 30 days afterwards 9,[12][13][14][15][16][17][18][19] , as the presentation of PI originating from the intraoperative phase may be delayed 8,44 .One reviewed quality improvement study 16 did not specify the breakdown of location or stage of post-operative PI's in its sample, and post-operative PI was only reported in general terms following process change.Therefore, it is difficult to accurately ascertain the incidence of perioperativeoriginated PI.
The most often reported locations of post-operative PI such as the coccyx and/or heel and/or buttock are related to supine surgical position being the most common for surgery 12,13,17,18 , and the forehead and/or chin in prone or jackknife positions 14,15 .Patients undergoing cardiac and vascular surgery were identified as being at greater risk of developing PI post-operatively than in other surgical specialties due to associated length of surgery and/or less repositioning during surgery 12,13,17,18 .A number of studies assessed skin at different postoperative time points for up to seven days following surgery, with Stage 1 or Stage 2 PI frequently reported 12,13,17,18 .More studies identified the multiple risk factors associated with postoperative PI, and tested some interventions for post-operative PIP e.g. the use of pressure-redistribution surfaces [45][46][47][48] .
In summary, five key PIP strategies based on modifiable PI risk factors were identified in the review and were also supported in the current clinical practice guidelines 8 .The frequency of the five PIP strategies reviewed in the selected articles is displayed in Table 3. Support surfaces in relation to surgical position were frequently examined [13][14][15][17][18][19][20] , while thermoregulation 9,13 and the use of medical devices and/or equipment were less frequently reported 15,19 .
While the main focus of the selected articles was different, there were some similarities in the selection of PIP risk factors and strategies, as shown in Table 4. Patients undergoing cardiac surgery were the population of interest in four studies 12,13,17,18 .In addition to other identified risk factors, length of surgery was found to be a risk factor associated with developing PI in three studies 9,13,18 , while another study found no such association 19 .Patients' comorbidities were examined in two studies, with positive associations found with PI development 13,18 .

Limitations and strengths
This review has several limitations related to data searching and study methods and appraisal.Some papers may have been missed, even though the search was systematic and the terms used were broad.Some selected studies used secondary data that could have been inaccurate or incomplete.
Although there may have been some variability of data appraisal because of individual perceptions, attempts were made to reduce this via the independent assessment by two raters, with adjudication by a third rater when necessary.As such, this method achieved a high ICC.The overall quality of this review was strengthened by the use of a systematic and rigorous approach when undertaking this review 1,10 .

Conclusion
This paper has presented a comprehensive review of the literature related to PIP in the perioperative setting.Five key PIP strategies were identified and categorised according to the published literature.Implementation of these key five PIP strategies should be based on consideration of patients, case-related and environmental factors.This review has identified a lack of research related to the observed PIP practices of health professionals in the perioperative setting.Therefore, a further research study is needed to address this knowledge gap.

Table 1 :
Screening results

Table 2 :
Characteristics of included studies

Table 3 :
Number of selected studies that examined the five key PIP strategies

Table 4 :
Number of key variables examined across selected articles