End Stage Lung Disease, Lung Transplantation
Conditions
Keywords
lung transplant candidates, diaphragm ultrasound, limb muscles ultrasound, respiratory muscles, quadriceps muscles, rehabilitation
Brief summary
The goal of this observational study is to evaluate respiratory and limb muscle properties in adults awaiting lung transplantation and determine how these measures relate to physical performance, symptoms, and recovery after transplantation. Respiratory and limb muscle weakness may contribute to impaired mobility, frailty, and delayed postoperative recovery, but their specific role in lung transplant candidates is not well understood. Participants will undergo muscle ultrasound imaging at weekly basis, respiratory and limb strength testing, physical performance assessments, and symptom questionnaires once before and after transplantation. Researchers will also collect information from medical records regarding intensive care unit stay, hospital length of stay, rehabilitation participation, and postoperative recovery outcomes.
Detailed description
Respiratory and peripheral muscle dysfunction are common in individuals with advanced lung disease awaiting lung transplantation. Muscle weakness, atrophy, and impaired contractile function may contribute to reduced physical performance, frailty, symptom burden, and delayed recovery after transplantation. Although physical function tests provide an overall assessment of performance, they provide limited information regarding specifics of respiratory and limb muscle impairments. Ultrasound imaging is a noninvasive and reliable method to evaluate muscle structure, quality, and contractile function and has been associated with clinical outcomes in several critically ill populations, including prolonged mechanical ventilation, longer intensive care unit (ICU) and hospital stays, and increased morbidity. The purpose of this study is to characterize respiratory and limb muscle properties before and after lung transplantation and determine how these measures relate to physical performance, patient-reported outcomes, and postoperative recovery. Respiratory muscle function will be assessed using maximal respiratory pressure testing and ultrasound evaluation of the diaphragm and abdominal muscles. Limb muscle function will be assessed using ultrasound imaging and strength testing of the quadriceps muscles. Physical performance, frailty, dyspnea, pain, fatigue, anxiety, and ICU/hospital-related outcomes will also be evaluated. The central hypothesis of this study is that respiratory and limb muscle weakness, atrophy, and impaired contractile function are associated with poorer physical performance, greater symptom burden, and delayed postoperative recovery after lung transplantation. To test this hypothesis, a prospective observational study of adult lung transplant candidates will be conducted from their hospital admission to their post-operative day 14. Participants will undergo serial ultrasound imaging assessments before transplantation and during the early postoperative period along with symptom questionnaires; while respiratory and limb strength testing, functional assessments, symptom questionnaires will be collected on the first and last day of research visit. Collection of ICU and hospital outcomes will occur from the electronic medical record. The central hypothesis will be evaluated through the following aims: Aim 1: Evaluate relationships between respiratory strength and ultrasound measurements of contractile dysfunction in candidates awaiting lung transplant. Aim 2: Characterize the associations between respiratory and limb muscle properties (atrophy, strength), physical performance, and patient-centered outcomes (dyspnea, frailty, pain, fatigue, and anxiety) in pre-lung transplant candidates. Aim 3: Identify the influence of preoperative respiratory and quadriceps contractile function on the early postoperative mobility progression in lung transplant recipients Aim 4: Determine relationships between postoperative diaphragm dysfunction and functional status at hospital discharge
Interventions
DIAGNOSTIC_TESTRespiratory and Limb Muscle Assessment
Participants undergo serial assessments of respiratory and limb muscle structure and function before and after lung transplantation. Assessments include ultrasound imaging of the diaphragm, rectus abdominis, and quadriceps muscles; respiratory muscle strength testing; handgrip strength testing; knee extension strength testing; physical performance measures; and patient-reported outcome questionnaires.
Sponsors
University of Florida
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* 18 years or older. * Hospitalized as potential candidates for single- or bilateral-lung transplant surgery. * Hemodynamically stable for out-of-bed mobilization
Exclusion criteria
* Baseline cognitive impairment * History of previous solid organ transplantation or thoracic surgery * Existing phrenic nerve lesion * Lower limb amputation or fracture * External fixators or open wounds of the lower extremities * Diagnosed neuromuscular disorder. * Morbid obesity (body mass index \>45 kg/m²). * Any other medical condition that, in the opinion of the investigators, would make participation unsuitable.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Diaphragm structure | Weekly from baseline through postoperative day 14 (±2 days) | Diaphragm thickness (unit of measure: mm) assessed by ultrasonography |
| Respiratory Muscle Strength | Baseline and at postoperative day 14 (±2 days) | Maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) obtained during maximal respiratory efforts against a one-way valve. |
| Abdominal muscle structure | Baseline through postoperative day 14 (±2 days) | Rectus abdominis muscle thickness (measurement unit: mm) assessed by ultrasonography. |
| Limb muscle strength | At the first baseline visit and postoperative day 14 (±2 days) | Handgrip force and knee extension force measured using dynamometry. |
| Rectus femoris thickness | Baseline through postoperative day 14 (±2 days) | Rectus femoris muscle thickness (unit of measurement: mm) assessed by ultrasonography. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Five-Repetition Sit-to-Stand Test | Baseline and hospital discharge | Time required to complete five sit-to-stand repetitions as a measure of physical performance. Retrieved from the medical record. |
| Frailty Status | Baseline and at postoperative day 14 (±2 days) | Frailty assessed using the Clinical Frailty Scale (CFS), a 9-point scale ranging from 1 to 9, where 1 = Very Fit and 9 = Terminally Ill. Higher scores indicate greater frailty and a worse clinical status. |
| patient-reported symptoms | Baseline and at postoperative day 14 (±2 days) | Dyspnea, physical fatigue, and pain assessed using an 11-point numeric rating scale ranging from 0 to 10, where 0 indicates no symptom and 10 indicates the worst symptom severity ever experienced. Higher scores indicate worse symptom burden. |
| Six-Minute Walk Distance | Baseline and at hospital discharge, an average of 3 weeks after surgery. | Distance walked during the Six-Minute Walk Test (6MWT), retrieved from the medical record. |
| Anxiety | Baseline and at hospital discharge, up to an average of 3 weeks after surgery. | Anxiety assessed using the State-Trait Anxiety Inventory (STAI). The STAI score ranges from 20 to 80, with higher scores indicating greater anxiety and a worse outcome. Data will be retrieved from the medical record. |
Countries
United States
Contacts
CONTACTBarbara K Smith, PhD, PT
CONTACTWagner Souza Leite, PT
Outcome results
None listed