Assessment of Pressure Injuries Following Surgery: A Descriptive Study

Pressure injuries are common and a major health care problem worldwide.^1-5 The National Pressure Ulcer Advisory Panel (NPUAP) describes a pressure injury as “localized damage to the skin and/or underlying soft tissue usually over a bony prominence or related to a medical device or other device.”⁶ A systematic review by Gaspar et al⁷ indicated that pressure injuries cause complications such as increased pain, delayed recovery time and hospital discharge, reduced quality of life, increased treatment costs, and death. A pressure injury cost analysis study,⁸ conducted in Turkey and published in 2014, determined that the total cost of treating all pressure injuries ranged from $340 077 to $2 452 686 per year.

Ninety-five percent (95%) of pressure injuries are preventable with appropriate interventions and early risk assessments.⁹ Although a multidisciplinary team approach has been found to be key in reducing pressure injuries,⁴ preventing and treating pressure injuries in the health care environment remains primarily a nursing responsibility.¹ Pressure injuries are regarded as a key performance indicator of the quality of care, particularly nursing care, provided by health facilities.¹⁰ Prevention of pressure injuries is also an important factor in reducing costs, make nursing care visible, and affecting patient safety.⁸

Patients undergoing surgery are at high risk of pressure injury development. The incidence of operating room–acquired pressure injuries ranges from 8.5% to 66% depending on the research population, length of surgical procedure, and type of surgery.^3,11-15 In a prospective-analytic-descriptive study conducted in Turkey (n = 84 patients), the incidence of postoperative pressure injuries in surgical patients was found to be 54.8% and the incidence of pressure injuries due to surgery was 39.1% at the first postoperative day.¹⁶ In a descriptive study by Celik et al¹⁷ conducted among 151 surgical patients, the incidence of perioperative pressure injuries was 40.4%; for most patients (63.9%), the pressure injury developed on the third postoperative day. In addition, the majority of pressure injuries (93.4%) were stage 1.¹⁷

Surgical patients are at risk of the development of a pressure injury because of extrinsic and intrinsic factors.³ Extrinsic factors include the temperature of the operating room, type of anesthesia, position in which the patient is located, mattress surface, length of the operation, and devices used.^3,5 Intrinsic factors that increase susceptibility to a pressure injury include nutritional status, patient comorbidities, age, and incontinence.^3,5 Important risk factors for intraoperatively acquired pressure injuries include type of surgery, length of surgery, warming devices, positioning devices, positioning, hypothermia, anesthetic agents, vasoactive medications, sedation, moisture, and hemodynamic factors (hypotensive state, extracorporeal circulation, and blood loss).^3,17-20

Surgical nurses are responsible for identifying patients at risk of pressure injuries and for performing preventive measures. For surgical nurses to be able to work to prevent surgery-related pressure injury, it is essential for them to know the factors that play a role in the development of a pressure injury during the perioperative period and how to use instruments that measure pressure injury risk. In Turkey, there are a limited number of studies that investigate factors that play a role in the development of pressure injuries during the perioperative period. Therefore, the purpose of the current study was to determine pressure injury risk in surgical patients. It is hoped that the results will help guide surgical nursing practices, direct future studies, and contribute to the relevant literature.

Study design and sample. In this descriptive study, data were collected from May to December 2019. The study population consisted of consecutive patients who planned to undergo surgery in a university hospital operating room in Turkey.

The sample size was calculated by taking into account the incidence of pressure injury among surgical patients (54.8%) obtained from the work of Karadağ and Gümüşkaya.¹⁶ With the apparent deviation value of 1 from the mean, the smallest sample size calculated at 99% confidence level was 145, and the total sample size was determined as 160 with a back-up of 10%. Patients who were older than 18 years of age, had a surgical procedure lasting at least 2 hours, and who did not have a history of pressure injury in the preoperative period were eligible for study participation.

Ethical approval and patient consent. Ethical approval was obtained from the university ethics committee (reference number: 24/04/2019-20.478.486). Institutional permission was obtained from the hospital where the study was conducted. The purpose of the study was explained, information about the study was provided, and written participant informed consent was obtained during the preoperative visit the day before surgery. Patient names were not recorded to ensure confidentiality.

Data collection methods. Data were collected during the perioperative (preoperative, intraoperative, and postoperative) period. The researcher interviewed all patients face to face. Statements were recorded with paper and pencil on printed forms. Patients were visited 3 times by the researcher, and the data forms were completed at each visit. The researcher completed a personal information form and the Braden Scale when patients were admitted to the clinics in the preoperative period. During the surgery, the 3S Intraoperative Risk Assessment Scale and personal information form were completed. The presence of pressure injury symptoms in the postoperative period (immediately after surgery and 24 hours after surgery) was evaluated with the Postoperative Pressure Injury Observation Form. Preoperative and postoperative visits typically lasted approximately 15 to 20 minutes. To collect intraoperative data, the researcher remained with the patient in the operating room.

Preoperatively, patients completed the personal information form and were assessed for pressure injury risk using the Braden Scale. Additional sociodemographic and disease characteristics (nutritional type, albumin, hemoglobin, hematocrit level, concomitant diseases, smoking status, preoperative activity level, and American Society of Anesthesiologists (ASA) score were obtained from the paper medical records and from the patient interview. During surgery, operation time, surgery position, intraoperative body temperature, blood pressure, wetness under the patient, and the reason for the wetness were recorded. Also the 3S Intraoperative Risk Assessment Scale of Pressure Injury was completed during surgery.

The patients were evaluated in the recovery room immediately after surgery and in the clinic where they were hospitalized 24 hours after the surgery. In this evaluation, the patient’s skin integrity, skin moisture, vital signs, level of consciousness, activity level, and diet were checked. The postoperative evaluation form was completed through interview of the patient and observation.

The presence of pressure injury symptoms in the postoperative period (immediately after surgery and 24 hours after surgery) was evaluated using the Postoperative Pressure Injury Observation Form. In the postoperative period, patients who were at risk of pressure injury and their family members or caretakers received instructions regarding pressure injuries, preventive measures, and care by using a training booklet prepared by the research team. Routine nursing care provided during the intraoperative period consisted of continuing the assessment of the patient’s psychological and physiological status, promoting safety, and maintaining privacy.

Data collection tools.

Personal information form. This form was used to obtain data collected in the preoperative and intraoperative periods. In addition to demographic characteristics of individuals (such as age, weight, height, body mass index [BMI], sex, and marital status) and hospital departments, data collected also included method of nutritional intake (oral, enteral, or parenteral); albumin, hemoglobin, and hematocrit levels; comorbid diseases; smoking status; preoperative activity level; ASA score; presence of incontinence; type of surgical procedure; preoperative length of stay; and preoperative length of fasting time. For the intraoperative period, operation time, surgery position, intraoperative body temperature, blood pressure, wetness under the patient, and reason for wetness were recorded.

3S Intraoperative Risk Assessment Scale. This scale was developed by Gao et al²¹ in 2015 based on pressure injury risk factors of patients who underwent surgery. The scale includes 9 items: skin of the whole body, preoperative limb activity (limitations), body height/weight ratio, the skin under stress, intraoperative bleeding, operation time, intraoperative stress, intraoperative body temperature, and intraoperative body position (Figure 1). Scores for each item are determined on a 4-point (1 = low risk; 4 = high risk) Likert-type scale, and a lower score correlates with lower risk. The total score of the scale (ranging from 9 to 36) is obtained by summing the scores from each of the scale items. A patient with a score of 23 or higher is considered to be at high risk of pressure injury. The scale was adapted for use in Turkey by Soyer and Özbayir.²²

The Braden Scale. Developed by Braden and Bergstrom,²³ the scale was adapted into Turkish by Oğuz and Olgun²⁴ and its validity-reliability was found to be high. The scale includes 6 risk factors: sensory perception, moisture, activity, mobility, nutrition, and friction/shear. Friction/shear scores range from 1 to 3 points, and the other 5 risk items from 1 to 4 points, for a total score of 6 to 23. Scores 12 points and below indicate high risk, 13 to 14 points medium risk, and 15 to 16 points low risk. For people older than 75 years, a score of 15 to 18 points is considered low risk. This scale is used to assess the risk of pressure injuries in the hospital where the study was conducted, and it is also included in the nurse observation form.²⁴ This tool was used for preoperative assessment.

Postoperative Pressure Injury Observation Form. This form was created by the researchers to assess the patient’s postoperative skin integrity, vital signs, state of consciousness, activity level, and nutritional type. Skin integrity assessment was performed according to the National Pressure Ulcer Advisory Panel, European Pressure Ulcer Advisory Panel, and Pan Pacific Pressure Injury Alliance guidelines.²⁵ Intact skin was evaluated visually. The activity level was defined by moving the patient.

Data management and analysis. Data were recorded using paper and pencil and then entered into the computer by the researchers. Data were analyzed using SPSS Statistics 25.0 (SPSS Statistics for Windows, Version 25.0; IBM). In the data analysis, descriptive findings were presented in the form of number and percentage distributions as well as mean ± standard deviation, median interquartile range, and minimum and maximum values. The Shapiro Wilk test was used for compliance with normal distribution. A chi-square test was used for testing relationships between categorical variables. The Student t test, the Mann–Whitney U test, one-way analysis of variance, and the Kruskal–Wallis test were used for analysis. The results were evaluated in the 95% confidence range, and the significance level was P <.05.

The final study sample included 164 patients (mean age, 51.58 ± 15.96 years; range, 18–80 years); 89 patients (54.3%) were 52 years and younger. More than half of the patients (91, 55.5%) were female, and 76 patients (46.3%) were overweight (25.0–29.9 kg/m²).The majority (124, 75.6%) were married; 61 patients (37.2%) were high school graduates, and less than half of the patients (57, 34.7%) were employed. The breakdown by hospital department found is as follows: 47 (28.7%) participants had orthopedic surgery, 33 (20.1%) brain/nerve surgery, 22 (13.4%) general surgery, 19 (11.6%) urological surgery, 18 (11%) plastic surgery, 17 (10.4%) obstetrics and gynecology, and 8 (4.8%) ear, nose, and throat.

Preoperatively, the majority of participants (119, 72.6%) were nonsmokers, able to consume food orally (159, 97%), and had normal albumin, hemoglobin, and hematocrit levels (Table 1, Part 1 and Part 2). Among all patients, 67 (40.9%) had a comorbidity (hypertension, diabetes, vascular disease). In the preoperative period, 8 patients (4.9%) had urinary incontinence and 89 (54.3%) were scored as ASA I. Preoperative activity levels of 116 patients (70.7%) were either not limited or only slightly limited. Ninety-three (93) patients (56.7%) had a preoperative hospital stay longer than 2 days, 8 (4.9%) had same-day surgery, and 114 (69.5%) had a preoperative fasting period less than 12 hours.

The mean Braden Scale score in the preoperative period was 19.96 ± 1.81 (range, 11–23); 134 patients (81.7%) were evaluated as not at risk, 27 (16.5%) as low risk, 2 (1.2%) as moderate risk, and 1 (0.6%) as high risk. The 3S Intraoperative Risk Assessment Scale mean score was 17.92 ± 3.03 (range, 10–26). Of the participants, 152 (92.7%) were evaluated as low risk and 12 (7.3%) as high risk (Table 2).

The mean duration of surgery was 169.51 ± 32.79 minutes (range, 120–285). Surgery positions included supine (90 patients, 54.9%), prone (41 patients, 25%), lithotomy (28 patients, 17.1%), and lateral (5 patients, 3%). During the operation, 133 patients (81.1%) experienced hypothermia, 40 (24.4%) had hypotension, and 87 (53%) had wetness underneath them (this was caused by the antiseptic solution used in 54 patients [62.1%]) (Table 3).

Skin assessment conducted immediately after surgery showed blanchable redness of a localized area (105 patients, 64%) and nonblanchable redness of a localized area, usually over a bony prominence (11 patients, 6.7%), indicating pressure injury (Table 4). Locations included the iliac (3, 27.27%), sacrum (6, 54.55%), gluteal (1, 9.09%), and hip (1, 9.09%) areas. In 48 patients (29.3%), intact skin was noted immediately after surgery. In the skin assessment conducted 24 hours after surgery, 8 patients (4.9%) had blanchable erythema and 156 patients (95.1%) had intact skin. Also in the assessment conducted 24 hours after surgery, 54.9% of patients were mobile with help, 39.6% were mobile, and 5.5% were not mobile. All patients were conscious, oriented, and receiving oral nutrition after surgery.

Nonblanchable erythema (stage 1 pressure injury) occurred in 100% of patients who were nonsmokers, 8 patients (72.7%) with comorbidities, 9 (81.8%) hospitalized for more than 2 days before surgery, 8 (72.7%) with ASA II, 6 (54.5%) who underwent surgery in the lithotomy position, 10 (90.9%) with body temperature < 36.1°C  (± 2), 3 (27.3%) who had hypotension during surgery, 10 (90.9%) who had wetness under gluteal and sacral areas during surgery, and in all 11 patients with a long operation time (median, 240 minutes). Locations included the iliac region (3 patients in prone position), sacrum (6 patients in lithotomy position), gluteal (1 patient in supine position), and hip (1 patient in lateral position).

A statistically significant difference was noted between patients who had intact skin (48 patients, 29.3%) and those who had blanchable redness of a localized area (105 patients, 64.0%) and nonblanchable redness (11 patients, 6.7%) in the immediate postoperative period (P <.05). Values of Cramér’s V, used to determine the effect size (size of the difference) of these variables, were observed to have low and moderate effects (Table 5, Part 1 and Part 2).

When the comparisons between the Braden Scale score and the factors affecting the risk of pressure injuries were examined, a statistically significant difference was found between the Braden Scale score and the following variables: nutrition type (z = -3.273; P = .001); albumin (z = -4.148; P = .000), hemoglobin (z = -3.658; P = .000), and hematocrit (z = -4.002; P = .000) values; presence of comorbidity (z = -2.350; P = .019); ASA score (X² = 18.837; P = .000); preoperative activity level (z = -7.576; P = .000); duration of preoperative hospital stay (X² = 13.907; P = .001); surgery position (X² = 25.829; P = .000); and the status of hypotension during surgery (z = -3.175; P = .001). Patients with enteral-parenteral feeding; low albumin, hemoglobin, and hematocrit values; a comorbid condition; high ASA score; limited preoperative activity; preoperative hospital stay longer than 2 days; surgery in the prone position; and hypotension during surgery had lower scores on the Braden Scale (Table 6, Part 1, Part 2, Part 3, Part 4).

When the comparisons between the 3S Intraoperative Risk Assessment Scale scores and the factors affecting the risk of pressure injuries were examined, the following variables were found to be statistically significantly different: BMI (X² = 22.902; P = .000), hemoglobin (z = -2.881; P = .004), hematocrit (z = -2.258; P = .024), presence of concomitant disease (z = -2.297; P =.022), ASA score (X²= 8.712; P = .013), preoperative activity level (z = -5.326; P = .000), duration of preoperative hospital stay (X² = 21.543; P = .000), surgery position (X² = 77.905; P = .000), intraoperative body temperature (z= -5.516; P = .000), and hypotension (z= -5.726; P = .000). Patients, with high BMI, low hemoglobin and hematocrit values, comorbidity, ASA score II and above, activity limitation in the preoperative period, long preoperative hospital stay, hypothermia, and hypotension during surgery had higher scores on the 3S Intraoperative Risk Assessment Scale (Table 6).

In summary, 11 patients (6.7%) had immediately postoperative intact skin with nonblanchable erythema (stage 1 pressure injury). High BMI, low hemoglobin and hematocrit values, concomitant disease, ASA score of II and above, activity limitation in the preoperative period, length of preoperative hospital stay, hypothermia, and hypotension during surgery were found to increase the risk of pressure injury.

In this descriptive study, the surgery-related pressure injury incidence was 6.7% immediately after surgery. The results of this study indicated that intraoperative risk factors, such as long operation time, wetness under the patient, and hypotension, play a role in the development of pressure injuries.

Other studies have found the incidence of surgery-related pressure injuries to have a large range (from 8.5% to 66%).^3,11-15 The incidence in this study of 6.7% is lower than the range stated in the literature. The low incidence of pressure injuries may be explained by the lower surgery times compared with other studies.

BMI is a factor affecting the development of a pressure injury.^10,18,26 In the current study, 46.3% of patients were overweight, and 45.5% who had nonblanchable redness after surgery were overweight. However, this study found no significant difference between the development of pressure injuries and BMI. In their prospective study among 172 patients conducted to evaluate the incidence of injury due to surgical positioning, as well as to try to identify pressure injury risk factors, Menezes et al²⁷ found a significant relationship between pressure injury and BMI. The incidence of pressure injury was found to be higher in patients with a BMI greater than 30 kg/m² compared with patients with a BMI less than 30 kg/m² in other studies.^28-31

Nutritional status is another factor affecting pressure injury development in patients undergoing surgery.^10,18,26 Inadequate nutrient intake and malnutrition can increase the risk of pressure injuries.²⁵ In the current study, nearly all patients (97%) were able to consume food orally.

Studies also have shown that an albumin level less than or equal to 3 g/dL can affect the development of pressure injuries during the surgical process.^2,27,32,33 In the present study, most patients (85.4%) had normal albumin levels (3.5–5.2 g/dL). Nonblanchable redness was observed in 27.3% of those with low albumin levels in this study. Because low hemoglobin levels allow less nutrient and oxygen transport to tissues, negatively affecting the preservation of skin integrity,^{2,27,28,32,33} they are also factors that will affect pressure injury development. However, in the current study, patients who received oral nutrition and had normal albumin, hemoglobin, and hematocrit values were found to be at increased risk of pressure injury (P < .05), which is supported by Braden Scale assessment.

Nearly half of the patients in this study had ASA scores of II and III. As noted by Menezes et al,²⁷ patients with ASA scores of II and III have a higher risk of pressure injuries and pressure injury incidence during the perioperative period compared with patients who have an ASA score of I. In this study, patients with ASA scores of III had a higher risk than patients with ASA scores of I and II in terms of pressure injury, according to the Braden Scale assessment.

A systematic review by Torossian et al³⁴ showed that inadvertent hypothermia occurs in approximately 25% to 90% of surgical patients during surgical and postoperative periods; factors such as duration of anesthesia greater than 2 hours, low ambient temperature (18 to 21° C) in the operating room, and intraoperative infusion of large volumes of unwarmed solutions or transfusion of cold red blood cell concentrates (4° C) cause body temperature to drop.³⁴ In a cross-sectional and analytical study, 88.6% of patients had hypothermia with a minimum temperature of 31.4° C at the end of anesthesia.³⁵

A 1° F (0.55° C) drop in body temperature has been found to cause a 20.2% increase in the risk of developing operation room–acquired pressure injuries.³⁶ Most patients (81.1%) in the current study were hypothermic during surgery. A warming device was not used. Patients with hypothermia had high scores on the 3S Intraoperative Risk Assessment Scale.

One of the most important risk factors for the development of an operating room–acquired pressure injury is the duration of anesthesia. Prolonged immobility and pressure exposure cause anoxia, tissue necrosis, and, as a result, skin damage.^37,38 A 1-hour surgery can increase the risk of pressure injury development by 1.07 times.³⁹ In surgeries exceeding 2 hours, the risk of pressure injury increases as the oxygenation of the compressed tissues will be affected.³⁰ The mean duration of surgery in this study was approximately 3 hours (169.51 ± 32.79 minutes). Only patients whose surgery took more than 2 hours were included in the study.

This study included patients who had surgery in various surgical positions. Most underwent surgery in the supine or prone position. Studies have shown that pressure injury risk is greater in the prone and lithotomy positions.^{10, 21,40} In the supine position, complications may occur if the patient is not placed in the correct position, stays in the same position for too long, or pressure points are not supported.^2,33 In this study, patients who had surgery in the prone position had a higher risk of developing a pressure injury according to 3S Intraoperative Risk Assessment Scale.

Preoperative risk of pressure injury was evaluated using the Braden Scale. The majority of patients (81.7%) were assessed as not being at risk of pressure injury development. Immediately after surgery, 29.3% of patients had skin integrity. In the literature, the Braden Scale is the most frequently used instrument to determine the risk of pressure injury development in surgical patients.^12,16 An experimental study conducted by Gül and Karadağ³⁸ in Turkey found an association between the Braden Scale score and the development of pressure injury in surgical patients. A retrospective case–control study by Kim et al⁴¹ stated that higher Braden Scale scores upon admission were correlated with surgery-related pressure injuries. Conversely, other studies reported that the Braden Scale was not effective in defining the risk of perioperative pressure injury.^14,42 A meta-analysis conducted by He et al⁴² found that the Braden Scale had low predictive validity for hospital-related pressure injuries in surgical patients. Although the Braden Scale is effective in evaluating pressure injury in home care patients, it may not be appropriate for determining the risk of perioperative pressure injury. These findings show the importance of using risk assessment tools that are specific to surgical patients.

This study was conducted with patients who had surgery at 1 university hospital. Therefore, the results can only be generalized to patients representing the characteristics of this sample group. The patients were not followed for an extended period after surgery, and some pressure injuries may not have been visible within the study timeframe. Only patients with an operative time of more than 2 hours were included in the study. The mean duration of the surgeries included was 3 hours. The occurrence of operating room–acquired pressure injury is higher in the literature than in the current study. This may be because the number of long operations in this study was relatively low and patients were not followed for a longer period.

This descriptive study was conducted to determine pressure injury risk factors in surgical patients. According to the Braden Scale, the majority of patients participating in the study were not at risk, and according to the 3S Intraoperative Risk Assessment Scale, all surgical patients were at risk of pressure injury; the majority of patients were at low risk. Among the 6.7% of patients who developed a stage 1 pressure injury (nonblanchable redness) immediately after surgery, high BMI (30.0–34.9 kg/m²), low hemoglobin (<12.5 g/dL) values, low hematocrit (<35%) values, a comorbid condition, ASA II and III scores, activity limitations in the preoperative period, length of preoperative hospital stay, hypothermia, and hypotension during surgery were found to significantly increase the risk of pressure injury. The 2 scales used to assess the risk of pressure injuries in surgical patients presented differing results.

Surgical nurses should assess pressure injury risks with appropriate risk assessment scales in order to apply interventions to avoid pressure injuries at various stages of the perioperative period. These interventions can contribute to ensuring patient safety and quality care. More study is required to further understand the risk factors that contribute to the development of pressure injuries during surgery.

The authors thank all the patients involved in this study and the surgical team.

Dr. Yılmaz is a professor and Dr. Başlı is a research assistant, Manisa Celal Bayar University, Faculty of Health Science Department of Surgical Nursing, Manisa, Turkey. Address all correspondence to: Emel Yılmaz, PhD, Manisa Celal Bayar University, Faculty of Health Science, Department of Surgical Nursing, 45030 Yunusemre Manisa, Turkey; tel: +90 236 233 09 04; fax: +90 236 233 71 69; GSM: +90 535 4684874; email: emelyilmazcbu@gmail.com.