Exploring The Diagnostic Accuracy of Ineffective Peripheral Tissue Perfusion For Nursing Care in Diabetic Foot Patients

Summary

This study evaluates the diagnostic accuracy of the nursing diagnosis "Ineffective Peripheral Tissue Perfusion" in diabetic foot patients against TcPO₂ as the gold standard and identifies key defining characteristics for a more precise diagnostic model.

Abstract

“Ineffective Peripheral Tissue Perfusion" is a recognized NANDA-I nursing diagnosis, but its diagnostic accuracy for diabetic foot patients lacks evidence-based support. This study aimed to evaluate the diagnostic accuracy of this nursing diagnosis in hospitalized diabetic foot patients. A retrospective study of 89 diabetic foot patients was conducted from January 2023 to December 2024. Trained nurses independently applied the NANDA-I diagnosis. Transcutaneous oxygen pressure (TcPO₂) < 30 mmHg served as the gold standard. Receiver operating characteristic (ROC) curves were plotted to calculate the area under the curve (AUC), sensitivity, and specificity for the overall diagnosis and for each of its 12 defining characteristics. The top three characteristics were combined into a new diagnostic model.

Compared to the TcPO₂ gold standard, the nursing diagnosis showed a sensitivity of 83.33% and a specificity of 86.96%, with an AUC of 0.851. Among the diagnostic performances of the 12 defining characteristics, "Color does not return to lowered limb after 1 min leg elevation" had the best performance (AUC=0.881), followed by "Edema" (AUC=0.835), and "Absence of peripheral pulses" had moderate performance (AUC=0.712). The combined diagnosis had a sensitivity of 84.85%, a specificity of 91.30%, PLR and NLR values of 9.76 and 0.17, respectively, and an increased AUC of 0.904, indicating superior overall diagnostic performance of the combined diagnosis. The AUC of the combined diagnosis was 0.053 higher than that of the nursing diagnosis, with a statistically significant difference (p=0.048).

The nursing diagnosis "Ineffective Peripheral Tissue Perfusion" is a valid tool for assessing diabetic foot patients. However, a focused assessment for "Color does not return to lowered limb after 1 min leg elevation," "Edema," and "Absence of peripheral pulses" provide even greater diagnostic accuracy.

Introduction

In the global spectrum of chronic diseases, diabetes has emerged as a significant public health threat to human health, with its prevalence increasing annually¹. According to the latest epidemiological survey released by the International Diabetes Federation (IDF), the global prevalence of diabetes among individuals aged 20-79 was 10.5% in 2021, with the number of affected individuals reaching 537 million. It is projected that this proportion will rise to 12.2% by 2045, with the number of patients reaching 783 million². Diabetic foot is one of the complications that severely endanger the life and health of diabetic patients, and its pathogenesis involves multiple pathological changes, including vascular disease, neuropathy, infection, and internal environment imbalance^3,4. If timely and appropriate treatment measures are not taken for patients with diabetic foot, the ulcer symptoms in their feet may continuously deteriorate, leading to severe infection and even amputation⁵. Diabetic foot refers to the presence of infection, ulcer, or tissue destruction in the feet of patients who are newly diagnosed with diabetes or have a pre-existing history of diabetes, often accompanied by peripheral neuropathy and peripheral arterial disease⁶. Even among patients who achieve clinical healing through standardized treatment, the one-year recurrence rate of diabetic foot ulcers is 40%, while the three-year recurrence rate rises to 65%^7,8. The lifetime incidence of amputation among patients with diabetic foot is as high as 20%, with a 5-year mortality rate ranging from 50% to 70%⁹. Therefore, early identification and timely intervention of diabetic foot are of positive significance for improving the quality of life of diabetic patients.

In the progression of diabetic foot disease, inadequate peripheral tissue perfusion, as a critical pathophysiological link, significantly promotes the occurrence and deterioration of foot ulcers, infections, and gangrene, and independently increases the risk of amputation, serving as an insidious yet decisive factor in determining disease outcomes¹⁰. The term "perfusion" originates from the Latin word "perfusio," meaning "to flow through or into." In an anatomical context, it refers to the dynamic process by which blood delivers oxygen and nutrients to tissues and removes metabolic waste products through the arterial-capillary-venous pathway¹¹. For patients with diabetic foot, long-term hyperglycemia leads to vascular endothelial damage, basement membrane thickening, enhanced platelet aggregation, and decreased red blood cell deformability. Coupled with lipid metabolism disorders, oxidative stress, and chronic inflammatory responses, these factors ultimately result in peripheral arterial stenosis or even occlusion, causing localized microcirculatory hypoperfusion¹². Once the perfusion threshold falls below the tissue's metabolic demands, "Ineffective Peripheral Tissue Perfusion" occurs, manifesting as limb pallor, decreased skin temperature, weakened pulses, prolonged capillary refill time, Edema, pain, and even ulceration and gangrene. Therefore, accurately assessing the peripheral tissue perfusion status in patients with diabetic foot is of great importance.

In clinical nursing practice, nursing diagnoses serve as a crucial bridge linking nursing assessment and nursing intervention, playing an irreplaceable role in guiding nurses to provide scientific and effective nursing services to patients¹³. The North American Nursing Diagnosis Association International (NANDA-I), as a globally authoritative organization for nursing diagnoses, has formulated nursing diagnosis standards that are widely applied in clinical nursing work worldwide. The NANDA-I 2021-2023 classification officially established "Ineffective Peripheral Tissue Perfusion" as an independent entry, defining it as "inadequate blood supply due to reduced peripheral circulation, insufficient to meet tissue metabolic demands"¹⁴. As one of the formally recognized nursing diagnoses by NANDA-I, "Ineffective Peripheral Tissue Perfusion" should ideally serve as an important basis for nurses to assess the peripheral tissue perfusion status of patients with diabetic foot and to develop targeted nursing measures. However, regrettably, despite its frequent use in clinical settings, research on the diagnostic accuracy of this nursing diagnosis in the specific population of patients with diabetic foot remains relatively scarce, lacking sufficient evidence-based support to demonstrate its ability to accurately and reliably reflect the true peripheral tissue perfusion status of these patients. In actual clinical nursing assessment processes, nurses typically evaluate patients with diabetic foot for "Ineffective Peripheral Tissue Perfusion" based on the relevant standards established by NANDA-I. However, due to the complex and diverse conditions of patients with diabetic foot, along with significant individual differences, and the current assessment standards' inherent ambiguities and subjectivity in terms of indicator definition and judgment methods, there can be substantial discrepancies in the assessment results of the same patient by different nurses, making it difficult to effectively ensure the accuracy and consistency of assessments. This situation not only affects nurses' accurate judgment of patients' conditions but may also lead to a lack of targeted nursing intervention measures, thereby impacting nursing outcomes and delaying treatment opportunities for patients. For example, some nurses may misinterpret foot symptoms caused by non-perfusion-related issues as "Ineffective Peripheral Tissue Perfusion" due to an inadequate understanding of the assessment standards, leading to the implementation of unnecessary nursing interventions. Conversely, other nurses may overlook patients with genuine peripheral tissue perfusion deficiencies, failing to promptly implement effective interventions and allowing the patients' conditions to progress further.

Given the aforementioned clinical scenario, conducting research on the diagnostic accuracy of the nursing diagnosis "Ineffective Peripheral Tissue Perfusion" in patients with diabetic foot has become particularly urgent and necessary. This study utilized a retrospective cohort of 89 patients with diabetic foot hospitalized from January 2023 to December 2024. Transcutaneous oxygen pressure measurement (TcPO₂) < 30 mmHg was employed as the gold standard. Trained and consistent responsible nurses independently assessed "Ineffective Peripheral Tissue Perfusion" in accordance with the NANDA-I 2021-2023 classification. Receiver operating characteristic (ROC) curve analysis was conducted to calculate the area under the curve (AUC), 95% CI, sensitivity, and specificity of the diagnosis and its 12 defining characteristics. The objective was to quantify the diagnostic accuracy and identify key characteristics, thereby providing evidence-based support for nursing assessment in patients with diabetic foot. This study aimed to thoroughly investigate the diagnostic accuracy of the nursing diagnosis "Ineffective Peripheral Tissue Perfusion" in patients with diabetic foot through scientific and rigorous research methods, offering robust evidence-based support for the scientific application of this nursing diagnosis in clinical nursing assessment for patients with diabetic foot.

Protocol

The study was conducted in accordance with the Declaration of Helsinki¹⁷ and the protocol was approved by the Zhejiang Medical and Health Group Hangzhou Hospital Ethics Committee (Approval No.: 202604281616000065088). Written informed consent was obtained from all participants prior to inclusion in the study. All patient data were anonymized and handled confidentially to ensure privacy and data protection.

1. Preparation of study materials and personnel training

1. Development of assessment forms
   1. Create a standardized assessment form listing all 12 defining characteristics for “Ineffective Peripheral Tissue Perfusion” as per NANDA-I 2021-2023^{14,15,16,17,18}.
   2. Include fields for patient identifiers, assessment date, nurse signature, and TcPO₂ results.
   3. Design the form in both paper and digital formats to ensure consistency in data recording.
2. Training of nursing staff
   1. Recruit registered nurses with at least 2 years of clinical experience in diabetic foot care.
   2. Conduct a 4 h training session covering:
      1. Theoretical background of the nursing diagnosis.
      2. Standardized assessment techniques for each defining characteristic.
      3. Use of TcPO₂ monitor (demonstration only—actual operation is performed by trained technicians).
   3. Use case-based simulations to practice assessment and diagnosis.
   4. Administer a post-training evaluation consisting of 10 case scenarios.
   5. Certify only nurses who achieve ≥ 90% accuracy in the evaluation.
      NOTE: Training materials include the NANDA-I 2021-2023 manual, a protocol booklet, and video demonstrations of physical assessment techniques.
3. Preparation of TcPO₂ Equipment
   1. Calibrate the TcPO₂ monitor according to the manufacturer’s instructions before each use.
   2. Ensure an adequate supply of single-use heated electrodes and calibration gas.
   3. Verify that the device display and thermal regulation function correctly.

2. Patient screening and enrollment

1. Application of inclusion criteria
   1. Screen hospital admissions from January 2023 to December 2024 for patients with diagnosis of diabetic foot.
   2. Confirm that the patient is > 18 years of age.
   3. Verify diabetes diagnosis using WHO criteria (either all or anyone of the following):
      1. Previous specialist diagnosis documented in medical records
      2. Fasting plasma glucose ≥ 7.0 mmol·L^-1 on two occasions ≥ 24 hours apart
      3. HbA1c ≥ 6.5% (NGSP-certified method)
      4. Random plasma glucose ≥ 11.1 mmol·L^-1 with typical symptoms.
   4. Confirm diabetic foot diagnosis using IWGDF 2023 criteria¹⁶.
   5. Ensure the patient is undergoing first-time assessment for “Ineffective Peripheral Tissue Perfusion” during hospitalization.
   6. Confirm availability of complete clinical data, including all 12 defining characteristics and TcPO₂ results.
   7. Exclude patients with severe cognitive impairment or psychiatric disorders.
2. Application of exclusion criteria
   1. Exclude patients with non-diabetic foot lesions (e.g., trauma, infection, autoimmune, tumor).
   2. Exclude patients with a history of lower extremity revascularization within the past 3 months.
   3. Exclude patients with acute conditions affecting perfusion assessment (e.g., deep vein thrombosis, septic shock).
   4. Exclude patients with terminal malignancy, pregnancy, or lactation.
3. Informed Consent and Data Anonymization
   1. Obtain written informed consent from eligible patients prior to assessment.
   2. Assign a unique study identification number to each patient.
   3. Store all data in an encrypted database accessible only to authorized researchers.

3. Nursing diagnosis assessment

1. Environmental Preparation
   1. Conduct assessments in a quiet, well-lit room with a stable temperature of 22–24 °C.
   2. Ensure the patient is in a supine position with legs fully exposed.
   3. Allow the patient to rest for 10 min prior to assessment to stabilize circulation.
2. Assessment of defining characteristics
   1. Perform each assessment in the following order:
      1. Color does not return to lowered limb after 1 min leg elevation: Elevate the leg at 45° for 1 min. Lower the leg and observe the dorsal foot skin color. Record “positive” if color does not return within 1 min after lowering.
      2. Edema: Apply firm pressure over the dorsal foot for 5 s. Record “positive” if a visible pit remains after release.
      3. Absence of peripheral pulses: Palpate the dorsalis pedis and posterior tibial pulses bilaterally. Record “positive” if pulses are absent on the affected limb.
      4. Assess the remaining 9 characteristics using standardized definitions from the assessment form.
   2. Record all findings immediately on the assessment form.
   3. Do not discuss findings with the patient during assessment.
      NOTE: If the patient reports pain or discomfort during assessment, pause briefly and resume once comfortable.
3. Determination of nursing diagnosis
   1. Review all 12 recorded characteristics.
   2. Apply the NANDA-I 2021-2023 diagnostic criteria for “Ineffective Peripheral Tissue Perfusion.”
   3. Classify the diagnosis as “positive” if ≥ 6 defining characteristics are present, or as per institutional nursing diagnostic guidelines.
   4. Sign and date the assessment form.

4. TcPO₂ Measurement (Gold Standard)

1. Patient Preparation
   1. Position the patient supine with the foot fully supported.
   2. Clean the dorsal foot skin with a 70% alcohol swab and allow it to dry.
      ​CAUTION: Avoid using skin creams or ointments prior to measurement, as they may interfere with electrode adhesion and oxygen diffusion.
2. Electrode placement and measurement
   1. Attach a new heated electrode to the TcPO₂ monitor.
   2. Place the electrode on the dorsal foot, avoiding areas with ulcers, scars, or edema.
   3. Secure the electrode with adhesive tape to prevent movement.
   4. Initiate the measurement and allow 15-20 min for stabilization.
   5. Record the TcPO₂ value once it stabilizes (fluctuation < 2 mmHg over 2 min).
   6. Repeat the measurement on the contralateral foot if bilateral assessment is required.
   7. Classify TcPO₂ < 30 mmHg as indicative of “Ineffective Peripheral Tissue Perfusion”^20,21.
3. Post-measurement procedures
   1. Remove the electrode and clean the skin with alcohol.
   2. Discard the used electrode in a biohazard container.
   3. Document the TcPO₂ value in the patient’s study record.

5. Data compilation and analysis

1. Data entry and validation
   1. Enter all assessment and TcPO₂ data into a pre-designed spreadsheet.
   2. Verify entries against original assessment forms for accuracy.
   3. Resolve any discrepancies by reviewing the original nurse notes or repeating assessments if necessary.
2. Statistical analysis using SPSS
   1. Open SPSS and import the dataset.
   2. Code nursing diagnosis and TcPO₂ results as binary variables (1 = positive, 0 = negative).
   3. Generate a 2×2 contingency table to calculate sensitivity, specificity, PLR, and NLR.
   4. Perform ROC analysis for the nursing diagnosis:
      1. Select Analyze > ROC Curve.
      2. Set the nursing diagnosis as the test variable and TcPO₂ as the state variable.
      3. Output AUC with 95% CI.
   5. Repeat ROC analysis for each of the 12 defining characteristics.
   6. Rank characteristics by AUC and select the top three for combined modeling.
   7. Create a combined diagnostic variable defined as positive if ≥ 2 of the top three characteristics are present.
   8. Compare AUC of the combined model versus the original nursing diagnosis using DeLong’s test.

6. Combined diagnostic model application

1. Bedside assessment using top three characteristics
   1. Perform only the assessments for: Color return after leg elevation; Edema; Peripheral pulse absence.
   2. Score each characteristic as present (1) or absent (0).
   3. Sum the scores.
   4. Classify as “positive for perfusion deficit” if the sum is ≥ 2.
   5. If sum = 1, proceed to full 12-characteristic assessment for confirmation.
2. Integration into Nursing Workflow
   1. Incorporate the combined assessment into daily nursing rounds for diabetic foot patients.
   2. Document findings in the electronic health record using a structured template.
   3. Flag positive cases for further vascular evaluation and tailored nursing interventions.

Results

Table 1 presents the baseline characteristics of the 89 hospitalized patients with diabetic foot included in this study. In terms of gender distribution, there were 46 males (51.69%) and 43 females (48.31%), indicating a relatively balanced gender composition. The mean age of the patients was 68.55 ± 5.12 years, and the mean body mass index (BMI) was 24.64 ± 1.56 kg·(m²)^-1. The median disease duration was 9 (8, 11) years, suggesting that the majority of patients had long-standing di...

Discussion

Diabetic foot, as one of the most devastating chronic complications of diabetes, poses a severe challenge to global healthcare systems due to its high rates of amputation, recurrence, and mortality²². Insufficient peripheral tissue perfusion, a core pathophysiological mechanism underlying the development and progression of diabetic foot, results from the combined effects of vascular endothelial dysfunction, microcirculatory remodeling, and atherosclerosis induced by chronic hyperglycemia

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
75g Oral Glucose Tolerance Test (OGTT) Kit	Various (hospital supply)	Standardized medical-grade OGTT solution	Administered according to WHO diagnostic criteria for diabetes confirmation.
Ankle-Brachial Index (ABI) Measurement System	Hokanson, USA	MD6 / Doppler probe	Optional perfusion assessment tool referenced in discussion; not used as primary outcome.
Blood Glucose Monitoring System	Roche Diagnostics, Switzerland	Accu-Chek® Performa	Used for fasting and random plasma glucose measurements, calibrated regularly per manufacturer guidelines.
Capillary Refill Time Assessment Tool (Digital Timer)	Omron, Japan	HS-36T	Used for standardized measurement of capillary refill time (>3 seconds).
Edema Assessment Scale (Pitting Edema Grading)	Self-developed / Clinical standard	N/A	Used to classify edema severity (1+ to 4+) during physical examination.
HbA1c Analyzer	Bio-Rad Laboratories, USA	D-100™ System	NGSP-certified method with CV < 3% for diabetes diagnosis and monitoring.
Inter-Rater Reliability Checklist	Self-developed	N/A	Used during training to evaluate consistency among nurses in assessing defining characteristics.
Laser Doppler Perfusion Imager	Perimed AB, Sweden	PIM 3	Referenced in discussion for microvascular assessment; not used in current study.
Limb Elevation Support Pillow	Medical-grade foam	Standard hospital issue	Used for standardized 1-minute leg elevation test.
Peripheral Pulse Palpation Simulator (Training)	Kyoto Kagaku Co., Japan	M55A	Used during nurse training for pulse assessment consistency.
Statistical Analysis Software	IBM, USA	SPSS Statistics 25.0	Used for ROC curve analysis, AUC calculation, sensitivity, specificity, and other diagnostic performance metrics.
Transcutaneous Oxygen Pressure (TcPO2) Monitor	Radiometer, Denmark	TCM4	Used to measure tissue oxygen tension with heated electrode set at 43–44°C, following established protocols for peripheral perfusion assessment in diabetic foot.