Determining the frequency of pressure ulcers incidence and associated risk factors in critical care patients: A 3‐year retrospective study

Abstract

One of the key measures to prevent pressure ulcer is to identify the factors that influence them. This study aimed to assess the occurrence of pressure ulcers and their related risk factors in patients admitted to specialized care units. This research is a retrospective cohort study that was conducted in the critical care units of hospitals affiliated to Ardabil University of Medical Sciences. A total of 1158 patient records who were hospitalized in the intensive care unit (ICU) between 2021 and 2022 were selected from the research population using the available sampling method and based on the inclusion criteria. Data was collected using a researcher‐made checklist between April 2021 and December 2022. Data were analysed using analytical tests (chi‐squared test, regression test) and descriptive statistics (prevalence, mean, standard deviation, and median) tests. All 1158 patient files were examined without any sample loss. The average age of the patients was 58.59 ± 19.73 years. The study found a significant association between the occurrence of pressure ulcers and age, duration of hospitalization, weight, body temperature, and male gender (p‐value <0.001). Additionally, there was a significant association between the occurrence of pressure ulcers and the use of pain relievers, vasopressors, alpha‐blockers, calcium blockers, and angiotensin (p‐value 0.001). The study also investigated the association between nursing care practices and the development of pressure ulcers. The findings revealed that changing the angle of the bed, using a wavy mattress, repositioning the patient every 2 h, using a CPR bed for mobility, providing protective equipment, and applying physical restraint to the patient were all significantly associated with the likelihood of pressure ulcers (p < 0.001). The study showed that pressure ulcers in ICU patients are influenced by the type of disease and clinical factors in individuals. However, considering the conflicting results of this study with some other studies, more research is needed on this subject. It is suggested that appropriate measures be taken based on the patient's condition to prevent pressure ulcers in those admitted to the ICU.

1. INTRODUCTION

Patients admitted to the intensive care unit (ICU) often face challenges such as low mood and limited mobility due to factors like reduced consciousness, intubation, sedative medications, and communication barriers. These patients are at high risk of developing pressure ulcers, as they are unable to communicate discomfort caused by prolonged pressure on their bodies. ¹ Pressure ulcers are considered a key indicator of the quality of care provided, with their absence reflecting positive nursing care. ²

Although their percentage has decreased in recent decades due to the emphasis on repositioning and prevention of pressure ulcers, they are still one of the most important and complex problems in the ICU. More than half, around 60%, of all diagnosed pressure ulcers are created in the ICU.

Five million patients are admitted to intensive care units every year. The prevalence of pressure ulcers varies widely in each country and health system. In European hospitals, the prevalence ranges from 3.8% to 23%, while in American hospitals it is reported at 12.3%. A systematic review in Iran reported a prevalence of pressure ulcers in care departments, especially in Iran, at about 19.59%. ³

Additionally, the prevalence of pressure ulcers varies across clinical departments. It ranges from 2.3% to 23.9% in long‐term care, from 0.4% to 38.6% in acute care, from 0% to 17% at home, and from 0% to 6% in rehabilitation care. Overall, the prevalence of pressure ulcers in ICU patients is reported to be between 5% and 30%, with the intensive care unit having the highest incidence among healthcare units. ⁴

After cancer and cardiovascular diseases, pressure ulcers are considered the third most expensive disorder. The cost of treatment and management of these ulcers depends on their severity. Annually, over one billion dollars is spent on treating pressure ulcers. In England, approximately two billion pounds are spent each year on treating these wounds or complications resulting from them. In the United States, around 2.5 million pressure ulcers are treated annually at a cost of 11 billion dollars, presenting a costly and challenging issue for healthcare systems worldwide. ⁵ Unfortunately, there is a lack of statistics regarding the costs of pressure ulcers in Iran.

Nurses play a vital role in preventing and managing pressure ulcers by identifying risk factors and implementing effective preventive measures ⁶ that are simple, cost‐efficient, and aimed at reducing the incidence of pressure ulcers and related complications. ⁷ , ⁸

Several risk factors contribute to the development of pressure ulcers, including underlying health conditions, organizational practices, caregiver behaviours, healthcare personnel, and the nature of specialized care units. Factors like prolonged immobility, hemodynamic instability, vasopressor use, malnutrition, altered consciousness, low albumin levels, hypertension, obesity, elevated cholesterol, and diabetes have been identified as significant risk factors for pressure ulcers. ⁹ , ¹⁰ , ¹¹ The impact of BMI on pressure ulcer development remains unclear and requires further investigation. ¹² Patients with conditions like reduced consciousness, sepsis, cardiac arrest, or polytrauma are at higher risk for pressure ulcers, although there is conflicting data on specific risk factors. ¹³ Additionally, a review identified over 100 risk factors for pressure ulcers. However, the study highlighted the necessity for further research on the fundamental role of malnutrition, decreased albumin levels, and underlying conditions like high blood pressure. The only conclusive factor for the development of pressure ulcers identified in the study was the prolonged immobility of patients. ¹⁴ In a systematic review considered immobility, age, and vasopressor infusion as the most important causes of pressure ulcers. The importance of nutritional status and laboratory values such as haemoglobin and albumin levels were deemed to be of secondary importance. ¹⁵

Coleman et al. (2012), in a systematic review study examining 365 eligible articles, identified the most significant risk factors for pressure ulcers. These included mobility/activity, perfusion disorders (including diabetes), and pressure ulcer location. They also mentioned skin moisture, age, haematological indicators, nutrition, and general health status as important factors, but did not emphasize their significance as much as the three main areas. They expressed the need for further research in this area. Additionally, they noted that while temperature and the body's immune system may play a role in the development of pressure ulcers, more studies are required to determine their primary impact on pressure ulcer occurrence. ⁷ Regarding the importance and role of urinary incontinence in the occurrence of pressure ulcers, some believe that a patient admitted to the ICU usually has a Foley catheter, so urinary incontinence cannot be named as a cause of pressure ulcers. However, faecal incontinence, especially diarrhoea due to pH changes, can be a major factor in the development of pressure ulcers. ¹³ There is contradictory information regarding the role of vital signs in the occurrence of pressure ulcers. Some believe that changes in systolic and diastolic blood pressure do not significantly affect the occurrence of pressure ulcers, ¹⁶ while others have identified systolic blood pressure, diastolic blood pressure, and mean arterial pressure as important factors in the development of pressure ulcers. Studies have shown varying results based on gender. The prevalence of pressure ulcers in men is significantly higher than in women. ¹⁷ However, a review study indicated that there is still insufficient evidence regarding the role of race or gender in the occurrence of pressure ulcers. ⁷ Therefore, further research is needed to determine the role of gender as a risk factor for the development of pressure ulcers. ¹⁷

Of course, there is conflicting information regarding the risk factors of pressure ulcers. ¹⁸ , ¹⁹ , ²⁰ , ²¹ , ²² While elderly individuals are often more vulnerable to pressure ulcers due to factors like insensitivity, weakness, and compromised immunity, ²³ some studies have found no significant association between age and pressure ulcer incidence in certain patient populations. ²⁴ , ²⁵ , ²⁶

Various factors have been proposed as potential risk factors for pressure ulcers, with systematic reviews emphasizing the need for more research to clarify these factors. ⁸ , ⁹ , ¹³ Previous studies have examined variables such as nutrition, haematological markers, gender, underlying illnesses, age, and length of ICU stay in relation to pressure ulcers, yielding conflicting results and highlighting the need for further investigation. ²⁵ , ²⁶ , ²⁷ , ²⁸

This retrospective the study aims to determine the risk factors that contribute to the development of pressure injuries.

2. METHODS

2.1. Design

This retrospective cohort study was conducted from April 2021 to December 2022. Data collection took place from June 2021 to October 2022. The research samples were selected using an available sampling method from the research community based on the inclusion criteria.

2.2. Participants

The research population in this study included the records of all patients hospitalized in special care units of hospitals affiliated with Ardabil University of Medical Sciences (a province in the west of Iran). The study was conducted in the ICUs of four hospitals affiliated with Ardabil University of Medical Sciences, which have a total of 68 active ICU beds. The inclusion criteria were:

• Patients over 18 years old

• Hospitalization in the ICU

• Not having a pressure ulcer upon entering the hospital

• No hemiplegia or paraplegia

• No hospitalization period of <48 h in the ICU

• No occurrence of pressure ulcers within the first 48 h of hospitalization in the ICU

2.3. Exclusion criteria

Non‐availability or incompleteness of patients' records (must have at least 70% of the information on the study checklist, otherwise, they would be excluded from the study).

2.4. Audit tool

The method of data collection in this study was a researcher‐made audit tool. Data was extracted after conducting a literature review from 2010 to 2023. We searched various databases such as PubMed, Scopus, Web of Science, MagIran, and SID using relevant keywords such as pressure ulcer, related risk factors, pressure injury, decubitus ulcers, pressure ulcers, pressure ulcer, pressure wounds, and pressure‐induced skin and soft tissue injuries. A manual search in Google Scholar was also conducted. This questionnaire included demographic, clinical, and pathological variables (age, sex, BMI, underlying disease, smoking, and physiological variables) (Table 1). The validity of the audit tool was measured with the help of content validity. For this purpose, the audit tool was given to 10 members of the nursing faculty and resident anaesthesiologists in the intensive care department, and their comments were applied. Its reliability was also measured using Cronbach's alpha (α = 0.81). The cases used in the reliability phase were excluded from the study. For this purpose, the information of 20 cases was analysed, and its reliability was calculated.

TABLE 1.

Variables examined in the study based on the “researcher‐made questionnaire.”

Demographic variables Age

Variables related to pressure ulcers The onset time of pressure ulcer Number of pressure ulcers Location of pressure ulcers Progression of pressure ulcers Number of days hospitalized before pressure ulcers Previous history of pressure ulcer

Variables related to the disease Discharge time from ICU Length of stay in ICU Diagnosis at admission Previous history of hospitalizations Surgery time and type

Variables related to nutrition Albumin level a Malnutrition status Total protein intake b Nutrition protocol BMI (Body Mass Index) c

Health status and disease data Vital signs of patients, including body temperature, d systolic blood pressure, e diastolic blood pressure, mean arterial pressure, f arterial blood gas analysis results, fasting blood sugar, g blood oxygen saturation, h 24‐h intake and output, relevant laboratory values (blood glucose level, sodium, i haemoglobin, j creatinine, k urea, l leukocytes and haematocrit m ), level of consciousness, chip insertion and its duration, tracheostomy, occurrence or non‐occurrence of delirium, days of patient immobility and duration of fasting

Associated diseases Cardiovascular diseases, severe anaemia, peripheral vascular diseases, diabetes mellitus, kidney disease, liver disease, hemiplegia or paraplegia, spinal cord injury, high blood pressure, hyperlipidaemia, occurrence of sepsis or shock (septic shock, cardiogenic shock, hypovolemic shock), smoking history, alcohol consumption history, urinary and faecal incontinence, acute respiratory distress syndrome (ARDS) and respiratory status

Medications in use Vasopressor drugs (norepinephrine, epinephrine, vasopressin, phenylephrine, and dopamine) Drug dosage, duration of treatment, and maximum prescribed dose Use of painkillers and sedative drugs, duration, and maximum prescribed dose Level of sedation Treatment with corticosteroids, immunosuppressive drugs, kidney replacement therapy and its duration, prescription of muscle relaxants

^a Albumin levels in the blood range from 3.4 to 5.4 g/dL.

^b The normal range for adults is between 6.4 and 8.3 g/L.

^c The normal range for total body mass is between 18 and 25.

^d The normal internal body temperature ranges from 36.5°C to 37°C and skin temperature is around 37°C.

^e Blood pressure according to the American Heart Association: Normal blood pressure is 120/80 mm of mercury or lower. Readings below 90/60 mm of mercury indicate low blood pressure. Readings above 140/90 mm of mercury during pregnancy indicate high blood pressure or hypertension.

^f Normal average arterial pressure: The normal level is 120.

^g Fasting blood sugar: The normal range for fasting blood sugar is between 70 and 99 mg/dL.

^h Ideal blood oxygen level: Ideally, blood oxygen saturation should be as close to 100% as possible, but normal levels are above 95%.

ⁱ Normal sodium level: Sodium levels typically range between 135 and 145 mmol/L.

^j Normal haemoglobin level: Haemoglobin levels in the blood should be between 12 and 18 g/dL.

^k Normal creatinine levels: In men, the normal range is ~0.6 to 1.2 mg/dL. In women, the normal range is ~0.5 to 1.1 mg/dL.

^l Normal urea level in adults: The normal range for adults is 15–45 mg/dL.

^m Normal haematocrit levels: In men, the normal range is 41%–50%. In women, the normal range is 36%–48%. In children, the normal range is 30%–44%.

2.5. Data analysis

In this study, alpha values <0.05 were considered significant. Nominal and rank data were presented as absolute and relative frequencies, while numerical data with normal distribution were shown with mean and standard deviation, and numerical data with non‐normal distribution were presented with median and interquartile range. Nominal and rank variables were compared using Chi‐square test or Fisher's exact test in two groups: with and without pressure ulcers. Parametric numerical variables were compared using independent t‐tests, and non‐parametric variables were compared using the Kruskal–Wallis test between the two groups with and without pressure ulcers. All tests were two‐sided. Factors related to patients' pressure ulcers were investigated using univariate logistic regression models, and all variables with a p‐value higher than 0.20 in the univariate logistic regression test were included in the principal component analysis in multivariate model. Then the non‐significant variables were removed in a backward way.

2.6. Ethical considerations

This study is the result of a thesis approved by the ethics committee of Tehran University of Medical Sciences with the code IR.TUMS.FNM.REC.1399.172. Throughout the study, the researcher handled patient information discreetly and respected the confidentiality of the patients' demographic characteristics.

3. RESULTS

3.1. Demographic characteristics of patients

A total of 1158 records of patients in the special care units of X hospital during 2015–2018 were analysed. The average age of the patients was 58.59 ± 19.73 years, with a minimum and maximum age of 19 and 95 years. The mean age of the patients was 61. Results regarding the gender variable showed that most of the patients were male. The length of hospitalization for majority ranged between 6 and 30 days. Additionally, the majority of patients had no history of drug addiction. The study aims to determine the risk factors that led to the development of pressure ulcers.

In the first year, the incidence rate of pressure ulcers was 5.1%, in the second year, it was 4.2%, and in the third year, the incidence rate was 4.2%, and in the total of 3 years, it was 13.56%. Additional demographic information is provided in Table 2.

TABLE 2.

Demographic characteristics of patients participating in the study based on the information contained in the file.

Variable	Number	Relative frequency (%)
Gender
Male	676	58.38
Female	482	41.62
Total	1158	100
Number of hospitalized days before pressure ulcers accuracy a
Less than 10 days	652	56.5
More than 10 days	503	43.5
Total	1155	100
Length of stay in ICU
1–5 days	8	0.6
6–30 days	881	76
More than 31 days	269	23.4
Total	1155	100
Drug abuse b
Cigarette	134	11.62
Alcohol	8	0.1
Narcotics	37	3.2
Non	974	85.08
Total	1153	100
The occurrence of pressure ulcers	157	13.56
Braden scale	5	3
PONS tool c	152	97
Total	157	100
Mean/SD	58.59 ± 19.73

^a The days of hospitalization in the ICU are the days when the patient did not have a pressure ulcer.

^b The use of all kinds of drugs is like opium.

^c Preoperative Nutrition Score (PONS) is an assessment tool that helps identify high nutrition risk patients before surgery. This tool is used to develop a preoperative nutritional care pathway for these patients.

The clinical variables of the patients participating in the study, including the mean and standard deviation of clinical indicators, are presented in Table 3. The majority of patients in the ICU were mechanically ventilated, with majority having a duration of mechanical ventilation and endotracheal tube placement exceeding 10 days. The SIMV mode was the most commonly used mode in the mechanical ventilation device, accounting for 61% of cases. In terms of nutrition, the majority of patients were orally fed (70%), with majority receiving feeding for less than 10 days. Liquid oral feeding was the most common form of nutrition (57%), while continuous tube feeding was predominant (45%) for patients requiring tube feeding. Intravenous nutrition was administered in the form of amino acids (73%) and intralipid (27%). Additionally, 97% of patients were on absolute bed rest, and 49.2% had received narcotic painkillers.

TABLE 3.

Mean and standard deviation of clinical variables of patients participating in the study.

Variable	Mean	Standard deviation
FOUR score a	11.11	23.4
Diastolic blood pressure	90.15	13.76
Systolic blood pressure	124.91	35.27
Oxygen saturation	88.94	5
Ventricle pressure	33.11	42.6
PO2	70.35	32.70
PCO2	39.32	13.65
GSC index	12.47	3.58
PH	7.38	0.09
PCO2	39.32	13.65
BE	−1.25	7.10
PO2	70.35	32.70
HCO2	23.2	7.85
O2 saturation	91.06	7.08
Bed rest	9.52	11.46
Relative rest	3.12	2.3

^a FOUR Score is a clinical rating scale designed for use by medical professionals to evaluate patients with a low level of consciousness. It is a 16‐point scale with potential scores ranging from 0 to 16. A score of zero indicates a deep coma or brain death, while a score of 16 represents a fully conscious and alert patient.

3.2. Characteristics of pressure ulcers in patients

The results revealed that the majority of pressure ulcer occurred in winter (30%) and were predicted using the PONS tool (97%). Most of the patients had pressure ulcers in only one area of their body (80%). The location of the wounds is shown separately in Table 4 and was classified as Stage 1 pressure ulcers (77%). The wound size for majority was <4 cm² (80%), and the majority of pressure ulcers were observed without exudate (90.4%). The sacrum was the most common site for pressure ulcers (32.9%).

TABLE 4.

Frequency distribution location of pressure ulcers in patients admitted to the ICUs.

Location of pressure ulcers	N (%)
Sacrum	51 (39.2)
The shoulder a	2 (1.3)
Right shoulder	6 (3.9)
Left shoulder	1 (0.6)
Batex	17 (11)
Batex on the right	14 (9)
Batex on the left	12 (7.7)
Right ear	4 (2.6)
Left ear	4 (2.6)
Elbow	1 (0.6)
Right elbow	1 (0.6)
Left elbow	1 (0.6)
Right heel	1 (0.6)
Left heel	2 (1.3)
Behind the head	5 (1.9)
Other	35 (22.6)

^a The reason why “batex,” “shoulder,” and “elbow” are written in general and separated from “right” and “left” is because in some nursing reports, only the specific body part was mentioned without specifying whether it was on the right or left side.

3.3. Demographic characteristics and occurrence of pressure ulcers

The findings presented in Table 5 demonstrate a statistically significant association between the occurrence of pressure ulcers and factors such as age, duration of hospitalization, weight, body temperature, and gender (p < 0.001).

TABLE 5.

Association of demographic variables with the occurrence of pressure ulcers in study participants.

Dependent variable	Odds ratio	95% confidence interval	p‐value
Age (year)	1.01	1.11–1.15	0.001
Length of stay before pressure ulcer (day)	1.13	1–1.02	0.046
Length of stay (day)	2.43	1.78–2.43	0.001
Weight (kg)	1.45	1.07–1.94	0.001
Sex (male)	1.16	1.01–1.21	0.001
Body temperature (°C)	1.67	1.04–2.13	0.001
Background disease	2.78	1.08–2.06	0.02
Smoking	1.43	2.10–1.06	0.03

Specifically, for every year of increased age, the likelihood of experiencing pressure ulcers increased by 1%. Being male increased the chance of pressure ulcers increased by 16%. The regression test results showed that smoking increased the likelihood of pressure ulcers by 1.43 times compared with non‐smokers.

3.4. Clinical features and pressure ulcers

The results in Table 6 showed a significant association between the average level of consciousness upon admission to the hospital and at the time of discharge with the occurrence of pressure ulcers (p < 0.001). For each score increase in the level of consciousness upon admission and discharge, the chance of a pressure ulcer was 20%. There was also a significant association between hemodynamic indices, mean arterial blood pressure, mean systolic and diastolic blood pressure, and the incidence of pressure ulcers. The regression test revealed a significant association between the use of drugs such as sedatives, vasopressors, alpha blockers, calcium blockers, angiotensin, and the occurrence of pressure ulcers (p < 0.001). The use of sedatives, vasopressors, alpha blockers, calcium blockers, and angiotensin increased the incidence of pressure ulcers by 4.14, 1.82, 4.58, and 1.71 times, respectively. Conversely, the use of vitamin C, zinc, and albumin decreased the incidence of pressure ulcers by 0.86, 0.94, and 0.90 times. The regression test also showed that the BIPAP (bilevel positive airway pressure) mode increased the chance of pressure ulcers by 1.86 times compared with patients not connected to this mode.

TABLE 6.

Association of clinical variables with the occurrence of pressure ulcer in patients participating in the study.

Dependent variable	Odds ratio	95% confidence interval	p‐value
Mean level of consciousness upon administration	0.08	0.67–0.94	0.008
Mean level of consciousness at the time of discharge	0.88	0.84–0.92	0.001
Mean diastolic pressure (each point increase)	0.98	0.98–0.99	0.001
Mean systolic pressure (each point increase)	0.99	0.96–0.98	0.001
Albumin	0.94	0.51–0.97	0.001
Zinc (yes/no)	0.94	0.32–0.99	0.001
Vitamin C (yes/no)	0.86	0.51–0.94	0.001
Nitrogen (blood urea)	1.67	1.49–1.56	0.001
Creatinine	1.62	1.29–1.89	0.001
Uric acid	1.78	1.61–1.91	0.001
BIPAP	1.86	1.14–2.90	0.001
Tube feeding	1.54	1.46–2.32	0.001
Intravenous feeding	1.91	1.87–2.94	0.001
Liquids	0.65	0.46–1.96	0.001
High proteins	0.91	0.54–1.54	0.001

3.5. Pressure ulcers and nursing care

The results in Table 5 demonstrated a statistically significant association between changing the bed angle, using a wavy mattress, repositioning the patient every 2 h, utilizing a CPR bed, patient mobility, protective equipment, and physical restraint of the patient with the likelihood of pressure ulcers (p < 0.001). The odds ratio of pressure ulcer occurrence with the provision of nursing care is presented in Table 5.

4. DISCUSSION

The results of this study demonstrated an increased likelihood of pressure ulcers with age. Most studies also indicate that age is an independent and important factor in increasing the risk of pressure ulcers. ²⁹ , ³⁰ , ³¹ For example, in several study demonstrated that old age increases the likelihood of pressure ulcers in patients hospitalized in palliative care departments. ⁶ , ³⁰ , ³¹ , ³² , ³³ However, disagreement to another study, Manjo et al. showed no significant association between age and the incidence of pressure ulcers among patients with severe traumatic head injuries. ²⁴

One of the reasons age is associated with the risk of pressure ulcer is that the skin thins with age and can become very weak. Older people's skin may be damaged more easily and take longer to heal. Factors such as not eating and drinking enough, lack of mobility, memory and thinking problems, pain, and incontinence can lead to skin damage or ulcers. ³⁴

In this study, the average age of the patients was 58.59 ± 19.73 years old, indicating that the patients were either old or close to old age and were vulnerable in terms of the risk of pressure ulcer. Age is an important variable in the ICU, and old age plays a role in the occurrence and progression of pressure ulcers. Elderly people have less subcutaneous fat, skin thickness decreases, and sensory perception decreases.

A combination of these factors makes elderly patients prone to rapid tissue damage and less responsive to mechanical sensations as cues to change position than younger patients. Elderly people are more prone to pressure ulcers due to insensitivity, weakness, and low immunity. The most common stages observed in the ICU are pressure ulcers of the first and second degree. ²³

The study results also revealed a significant association between the length of hospitalization and the likelihood of ulceration. For instance, Peter's study et al. in England found that patients with pressure ulcers had longer hospital stays compared with the control group, with a statistically significant difference, ²⁷ Several studies focused on patients in ICUs, concluded that longer hospital stays increase the risk of pressure ulcers. ⁶ , ³² , ³³ , ³⁵ Overall, most scientific evidence supports the notion that hospitalization duration is linked to pressure ulcer risk. There is a consensus in the literature regarding this association, suggesting that hospitalization length is an important independent factor in pressure ulcer occurrence. Perhaps the prolonged duration of hospitalization causes the skin on body parts constantly in contact with the bed to become sensitive and susceptible, while also increasing the risk of pressure ulcer due to moisture build‐up. Additionally, lack of movement, advanced age, poor nutrition, and failure to change positions can further exacerbate the development of pressure ulcer.

Regarding the association between gender and pressure ulcer incidence, this study identified a significant association between being male and developing pressure ulcers. Studies by Kim et al. and Susan et al. both supported this finding. ³⁶ However, Efteli et al. reported conflicting results, showing no significant gender‐based association with pressure ulcers. ³⁷ Other studies by Maria and Sian also presented differing conclusions on this matter. ³⁶ , ³⁸ It is evident that additional variables beyond gender may influence the association with pressure ulcers, such as age and underlying health conditions. In this study, men were older on average and had more underlying diseases than women, potentially impacting the gender‐pressure ulcer association. As mentioned, one of the important factors contributing to bed sores is susceptible and fragile skin. Men are at a higher risk due to a lack of proper self‐care and skincare. Studies have also shown that non‐compliance with treatment and self‐care, including not following medical advice or recommendations, can increase the complications of hospitalization for patients. Therefore, men who pay little attention to these issues are at a greater risk. ³⁹ In the present study, the majority of participants were male (58.38%). On the other hand, men may be more likely to refuse certain nursing care tasks due to a lack of focus on health and skincare, as well as not fully adhering to treatment plans, which can further increase the risk for male patients.

The study also highlighted a significant association between body temperature and pressure ulcer occurrence. Higher body temperatures were linked to an increased risk of pressure ulcers, as metabolic activity rises with temperature elevation. ³⁶ , ⁴⁰ Various studies have supported this finding, ⁴¹ , ⁴² although conflicting results from Neleh et al. and Fredd et al. ⁴³ , ⁴⁴ suggest a need for further research in this area. Factors like medication use, environmental conditions, and disease complications can influence body temperature and subsequently impact pressure ulcer risk. Physiologically, an increase in skin temperature leads to an increase in tissue metabolic demand, approximately a 10% increase in metabolic demand for every 1°C increase in skin temperature. Increased skin temperature, especially in hospital mattresses when accompanied by increased humidity, can increase the risk of pressure ulcer. ⁴⁵ In this study, the average temperature of the patients was 37.66°C. The patients hospitalized in the special care department in this study were admitted due to different diagnoses. Since human body temperature is affected by environmental, therapeutic, care, and pharmaceutical factors, as well as unstable hemodynamic conditions of the patient, it is essential to control the patient's body temperature. This can be difficult. Therefore, patients are more prone to an increase in body temperature and, of course, an increase in skin temperature, which puts them at risk of pressure ulcers.

Additionally, the study indicated a significant association between weight gain and pressure ulcer occurrence. The association between body mass index and pressure ulcers, emphasising the need for more research in this area. ³⁶ , ⁴⁶ , ⁴⁷ The presence of underlying diseases was also found to significantly increase the likelihood of developing pressure ulcers, consistent with previous research. The results of the present study, were disagreement with Jan et al. (2014) found no significant relationship between body mass index and pressure ulcers. ⁴⁷ Evidence regarding the connection between weight gain and bed ulcer incidence is varied, with some studies indicating an increased risk, others suggesting a lower risk, and some showing no significant impact of weight on ulcer incidence. Research indicates that the risk of pressure ulcers is notably higher in individuals who are very obese compared with those with a normal body mass index. It appears that reduced mobility, particularly in chair and bed mobility, due to the issue of weight distribution in obese individuals has made these patients more vulnerable. ⁴⁸ In this study, the average weight of the patients was 76.43. Immobility, hormonal disorders, water and electrolyte imbalances, and the treatment process for these factors contribute to weight changes in ICU patients, putting them at risk for pressure ulcer.

Furthermore, hemodynamic indices such as mean arterial blood pressure, mean systolic and diastolic blood pressure were associated with pressure ulcer occurrence. Studies by Deborah et al. and Cox et al. supported these findings, although conflicting results exist due to various factors affecting blood pressure measurements and patient conditions. ⁴⁹ , ⁵⁰ The study population in this research had higher than normal average values for these variables, potentially contributing to the increased pressure ulcer risk. It appears that the mechanism of oxygen delivery is impacted in hypertensive patients. When blood pressure is elevated, oxygen flow becomes obstructed, leading to tissue death or decay. Consequently, the skin and underlying tissue are more susceptible to wounds and cracks. High blood pressure disrupts the circulation of oxygen in the body, decreasing tissue oxygenation and increasing the likelihood of scarring.

The study also identified a significant association between administered drugs and pressure ulcer occurrence, particularly vasopressors. Studies by Cox and Natalia confirmed the role of vasopressors in increasing pressure ulcer risk. ¹⁴ , ⁵⁰ The use of these drugs can impact blood pressure, temperature, and overall hemodynamics, thereby affecting pressure ulcer development. Vasopressors are medications used as a last resort to increase mean arterial pressure in critically ill patients suffering from hypoxia and impaired tissue perfusion. The pharmacodynamics of vasopressors suggests that these drugs may impact tissue tolerance and potentially contribute to the development of pressure ulcers. The vasoconstriction triggered by drug administration and the hypotension requiring their use can lead to inadequate perfusion of vital organs, including mesenteric organs and kidneys.

The findings of this study indicated that albumin can decrease the risk of pressure ulcers. Albumin plays a crucial role in patients experiencing acute events that necessitate prolonged hospitalization in the ICU. Its primary physiological functions include maintaining colloid osmotic pressure, binding and transporting metabolically active molecules, acting as an antioxidant, serving as a surrogate indicator of nutritional status, and exerting an antithrombotic effect on platelets. All of these functions contribute to skin integrity and overall bodily balance, helping to stabilize the body's hemodynamics. In the study, 20% of patients were administered vasopressor drugs. The use of vasopressor drugs poses a risk to patients by altering blood supply to the skin.

Moreover, average blood sugar, urea nitrogen, uric acid, creatinine, haemoglobin, and albumin levels were associated with pressure ulcer occurrence. Higher levels of blood sugar, urea nitrogen, and creatinine associated with increased ulcer risk, while elevated haemoglobin and albumin levels were linked to lower risk. ⁵¹ , ⁵² Studies by Raju et al. and other sources supported these findings, highlighting the importance of monitoring these biomarkers in pressure ulcer prevention. ⁵³ In our study, elevated haematological and laboratory indicators above normal levels are attributed to the patient's underlying disease, medication usage, and unstable hemodynamic conditions, thereby increasing the risk of pressure ulcer. High creatinine and urea nitrogen levels indicate elevated toxin levels in the body, some of which accumulate in the skin layers, posing a risk to patients.

The study also addressed the impact of mechanical ventilation, tube feeding, and intravenous infusion on pressure ulcer risk. Mechanical ventilation, particularly in ICU patients, led to a higher risk of pressure ulcers due to immobility and altered consciousness. Tube feeding and intravenous infusion were also linked to higher ulcer risk, whereas liquid, high‐protein, and high‐calorie diets were associated with lower risk. Preventive measures such as changing bed angles, using specialized mattresses, and repositioning patients were found to reduce pressure ulcer risk. These findings consistency with previous research emphasizing the importance of nursing interventions in preventing pressure ulcers. ⁵⁴ , ⁵⁵

In conclusion, this study contributes valuable insights into the multifaceted factors influencing pressure ulcer occurrence. By examining various demographic, clinical, and environmental variables, the study sheds light on the complex interplay of factors contributing to pressure ulcer development. Further research is warranted to explore these associations in more detail and develop targeted interventions to reduce pressure ulcer incidence.

4.1. Limitations

This study had several limitations. One of the main limitations was the lack of free access to hospital information. The storage of patient files in hospitals was disorganized and unsanitary, making it difficult to access relevant information. The files were still paper‐based, which prolonged the sampling process by nearly 2 years. Another significant issue was the inaccurate recording of patient information in the files and nursing reports. Incomplete nursing reports, illegible handwriting, improper report writing, and inaccurate recording of patient data were major problems. Additionally, there were very few mentions of nursing care in the reports. Specific statistics on the number of patients with pressure ulcers were not provided, only an index of the incidence of pressure ulcers. The validation department did not accurately register the number of pressure ulcer as it was considered a negative score. Lack of proper training in areas such as using specialized mattresses, physiotherapy, and feeding patients were also limitations during the research. The researcher created the checklist and questionnaire for this study. While their validity and reliability were assessed, using a standard questionnaire in this field may have yielded better results.

5. CONCLUSION

There is a significant relationship between hemodynamic indices, mean arterial blood pressure, mean systolic and diastolic blood pressure, and the occurrence of pressure ulcer. An increase of one unit of ART results in a decrease in the incidence of pressure ulcer by the coefficients of 0.97, 0.98, and 0.97 for systolic and diastolic blood pressure, respectively. Calcium blockers, angiotensin, and albumin also have a significant relationship with the occurrence of pressure ulcers. The use of sedatives, vasopressors, alpha‐blockers, calcium blockers, and angiotensin increases the incidence of pressure ulcers by 4.14, 1.82, 4.58, and 1.71 coefficients, respectively. However, the use of vitamin C, zinc, and albumin decreases the incidence of pressure ulcers with coefficients of 0.86, 0.94, and 0.90.

For every 1 year increase in age, the chance of pressure ulcers increases by 1%. The results also indicate that male gender has a significant relationship with the chance of pressure ulcers, with a coefficient of 1.16. A 1 kg weight gain and a one degree increase in body temperature result in an increased chance of wound occurrence by coefficients of 1.45 and 1.67, respectively. The duration of hospitalization is significantly related to an increase in the chance of pressure ulcers by a factor of 2.43. Additionally, having an underlying disease is significantly related to the chance of developing pressure ulcers, with an increase in the chance of pressure ulcers by 2.78.

The findings of the present study show a significant difference in the occurrence of pressure ulcers based on various factors. Changing the angle of the bed, using a wavy mattress, changing the patient's position every 2 h, moving with a CPR bed, patient mobility, and physical restraint all play a role in the development of pressure ulcers. Specifically, changing the bed angle to 45° decreases the chance of wound occurrence by a factor of 0.91. Conversely, not using a wavy mattress, failing to change the patient's position every 2 h, moving with a CPR bed, patient immobility, and physical restraint all increase the likelihood of pressure ulcers. The coefficients for these factors are 1.34, 1.78, 1.30, 1/60, and 1/38, respectively.

The results of this study have identified factors that can influence the occurrence of pressure ulcers. This data can help prevent pressure ulcers and their negative consequences, ultimately improving the health of patients in special care departments. The findings of this study offer valuable information for managing patients in special care units. It includes details on the incidence, demographic characteristics, and factors associated with pressure ulcers in these units, enabling better decision‐making to address this significant health issue.

CONFLICT OF INTEREST STATEMENT

The authors declare that they have no known competing financial interests or personal correlation that could have appeared to influence the work reported in this paper.

Noie A, Jackson AC, Taheri M, Sayadi L, Bahramnezhad F. Determining the frequency of pressure ulcers incidence and associated risk factors in critical care patients: A 3‐year retrospective study. Int Wound J. 2024;21(11):e70120. doi: 10.1111/iwj.70120

DATA AVAILABILITY STATEMENT

Data available on request from the authors.