UDOPAL Study: Home-Based Interventional Approach to Pain Management in Home-Hospitalized Patients

Introduction Pain is one of the most prevalent and distressing symptoms among patients receiving home hospitalization, especially those with chronic or oncologic conditions. Despite the advances in home-based medicine, the management of moderate to severe pain continues to be a clinical challenge. Conventional pharmacological treatment alone is often insufficient, and access to specialized interventional pain techniques remains limited to hospital settings. In traditional care models, patients experiencing uncontrolled pain must be transferred to the hospital for evaluation or intervention, leading to fragmentation of care, increased healthcare costs, and a significant emotional burden for patients and families. These transfers often disrupt the continuity of palliative and supportive care that the home-hospitalization environment seeks to provide. The UDOPAL Study (from Unidad del Dolor + Hospitalización Domiciliaria) was designed to address this gap by introducing a structured, collaborative model that enables interventional pain management to be performed safely and effectively at home. This initiative positions home-hospital professionals at the center of the intervention, empowering them to deliver advanced pain procedures within the patient's own environment, supported by the Pain Medicine Unit when required. The study reflects an evolution in the concept of pain management-shifting from a hospital-centered model to an integrated, patient-centered continuum of care. The UDOPAL model aligns with the principles of the World Health Organization and modern palliative medicine, emphasizing early, multidisciplinary, and accessible interventions that improve comfort, dignity, and quality of life. Beyond clinical innovation, the UDOPAL project also represents an organizational and educational advance: it introduces a systematic training framework for home-hospital professionals to perform ultrasound-guided and minimally invasive procedures for pain control, under a protocolized supervision system. This dual focus-clinical and educational-aims to ensure safety, reproducibility, and scalability of the model. Objectives and Hypothesis The UDOPAL Study is based on the hypothesis that interventional pain management procedures-when adapted, standardized, and safely performed by trained Home Hospitalization Unit (UHD) professionals-can improve pain control, functionality, and patient satisfaction while optimizing healthcare resource utilization. Primary Objective To evaluate the feasibility and safety of performing interventional pain management techniques at home by UHD professionals within the UDOPAL model. Secondary Objectives To describe the prevalence and intensity of pain among patients admitted to a Home Hospitalization Unit and to determine the proportion experiencing mild, moderate, or severe pain. To measure the reduction in opioid consumption, assessing whether improved pain control leads to decreased opioid requirements and fewer adverse effects. To analyze the improvement in patient functionality, evaluating whether better pain management reduces physical limitations and enhances functional capacity. To assess whether the UDOPAL model contributes to an increase in patients' quality of life. To evaluate patient and family satisfaction with pain management and overall home-based care. To explore the professional perception of the model's clinical impact among UHD and Pain Unit staff. To assess the implementation of the UDOPAL model in real clinical practice, identifying facilitators and barriers to its adoption. To analyze the healthcare demand generated by the UDOPAL model, including its influence on workload, care coordination, and service utilization. The working hypothesis is that the UDOPAL model will demonstrate high feasibility, a favorable safety profile, and significant clinical and organizational benefits compared to conventional home-based care, contributing to a more integrated, efficient, and patient-centered approach to pain management at home. Study Design The UDOPAL Study is an observational, prospective study designed to evaluate the early implementation of a novel home-based model for pain management in patients admitted to the Home Hospitalization Unit (UHD). The model integrates interventional pain procedures into standard clinical practice at home, performed by UHD professionals trained in the UDOPAL protocol, with support from the Pain Medicine Unit. The study assesses the impact of this integrated model on clinical, organizational, and perceived-quality outcomes, comparing results obtained before and after the implementation of the UDOPAL protocol. Particular attention is given to the effects of early intervention during the initial stages of clinical complexity, when timely pain control may influence the overall course of illness and quality of life. Study Population Adult patients (≥18 years) admitted to the Home Hospitalization Unit who present acute, chronic, or oncologic pain and may benefit from interventional pain procedures. Patients are identified by UHD professionals and managed according to the UDOPAL protocol once the intervention phase begins. Inclusion Criteria Patients admitted to the UHD. Presence of acute, chronic, or oncologic pain requiring advanced pain management. Indication for interventional pain techniques (e.g., peripheral nerve blocks, infiltrations, pulsed radiofrequency). Ability to understand and sign informed consent (or through a legal representative). Exclusion Criteria Contraindication to interventional techniques (coagulopathy, local infection, allergy to local anesthetics). Cognitive impairment or communication barrier that prevents adequate assessment. Absence of safe or logistically feasible home environment. Intervention and Comparison The UDOPAL model is implemented as an early intervention protocol combining pharmacologic optimization with minimally invasive pain procedures performed at the patient's home. UHD professionals trained under the UDOPAL framework conduct the interventions using portable ultrasound guidance and aseptic technique. The study compares two periods: Pre-intervention phase: standard home-hospitalization care before UDOPAL implementation. Post-intervention phase: care delivered under the UDOPAL protocol, integrating interventional pain management. Variables and Data Collection Clinical and service indicators are prospectively collected and compared between phases, including: Pain intensity (VAS/NRS). Opioid consumption (morphine-equivalent daily dose). Functional capacity and mobility. Quality of life and satisfaction of patients and families. Professional perception of impact on care quality. Resource utilization: emergency visits, hospital readmissions, and assistance demand. Sample Size and Duration Approximately 80-100 patients are expected to be included during a 12-month recruitment period. The sample size is pragmatic, based on UHD patient flow and expected feasibility of early intervention. Statistical Analysis Descriptive statistics will be used for baseline characteristics. Continuous variables will be compared between pre- and post-intervention phases using paired t-test or Wilcoxon signed-rank test, as appropriate. Categorical variables will be compared using χ² or Fisher's exact test. A p-value \<0.05 will be considered statistically significant. Ethical Considerations The study was approved by the Ethics Committee (CEIm Hospital Universitario y Politécnico La Fe, Acta No. 600, 08/10/2025). Written informed consent will be obtained from all participants. The study follows the Declaration of Helsinki and Good Clinical Practice guidelines. Implementation and Training Framework The UDOPAL Study is both a clinical and educational initiative aimed at ensuring that interventional pain techniques can be safely and effectively performed within the home-hospitalization environment. The model is implemented through structured professional training, standardized clinical protocols, and continuous quality evaluation. Professional Training Before implementation, UHD professionals (physicians and nurses) participate in a dedicated educational program coordinated by the Pain Medicine Unit. The curriculum combines theoretical modules-covering pain pathophysiology, pharmacologic optimization, and indications for interventional techniques-with practical ultrasound-guided workshops. Training emphasizes aseptic technique, patient selection, prevention of complications, and post-procedure follow-up. Clinical Implementation After completing training, UHD professionals progressively incorporate interventional pain procedures into their clinical practice, following the standardized UDOPAL protocol. Pain specialists from the Pain Medicine Unit remain available for consultation and case review, ensuring adherence to safety standards and technical consistency. Safety and Quality Assurance Safety is continuously monitored through the recording of procedure-related complications, unplanned hospital visits, and any adverse events. A predefined escalation pathway allows for immediate hospital transfer if necessary. All data are documented in a secure electronic case report form and reviewed monthly by the UDOPAL coordination team. Implementation Assessment The implementation process is evaluated using both quantitative and qualitative indicators: Quantitative indicators: number and type of procedures performed, success rate, complication rate, and time to pain relief. Qualitative indicators: professional perception of feasibility, coordination between units, and satisfaction with the training received. Expected Impact and Conclusions The UDOPAL Study seeks to generate clinical evidence supporting the feasibility and safety of performing interventional pain procedures within the home-hospitalization setting. By incorporating these techniques into early stages of patient management, the model aims to achieve more effective pain control, reduce opioid requirements, and improve functional capacity and perceived quality of life. In addition to its direct clinical benefits, the project is expected to strengthen collaboration between the Home Hospitalization Unit and the Pain Medicine Unit, promoting shared decision-making and continuity of care. The implementation process will also provide valuable insight into the practical challenges of integrating interventional pain management into routine domiciliary care. The results of this study will help define safe practice standards for interventional pain techniques performed at home and may inform future guidelines for comprehensive pain management in home-based patients. The UDOPAL Study represents a step toward more personalized, multidisciplinary, and accessible care for patients experiencing pain during home hospitalization.