2025/01/01 by Guerrero, Maria Camila Ojeda, Yenifer Clarena Henao Ramirez, Arteaga, Brenda Doris Sanchez +1
Medicine · Nursing · #Clinical Nutrition and Gastroenterology #Infant Development and Preterm Care #Intensive Care Unit Cognitive Disorders #Medicine and Health Sciences #Muscle weakness #Pediatrics #Respiratory Function Tests #cardiovascular deconditioning
paper · doi:10.17605/osf.io/q6u9h
openalex publication_date 2025/01/01 · openalex created_date 2025/12/04 · openalex updated_date 2026/07/01
Admissions to Pediatric Intensive Care Units (PICUs) have increased, exposing more children to the risks of critical illness and life-support therapies such as mechanical ventilation. Due to their unique physiological development, children are more vulnerable to immobility and prolonged sedation, which rapidly cause muscle loss, decreased cardiac function, and reduced physical capacity. Although no global prevalence of physical deconditioning in children exists, studies report functional impairment in 20–40% of critically ill pediatric patients in the United States and 10–36% in Singapore, with deficits persisting for years. In Latin America, prolonged PICU stays contribute significantly to deconditioning, particularly among children with complex chronic conditions. National data are lacking. Despite improvements in critical care, many survivors develop Post-Intensive Care Syndrome (PICS). In children (PICS-p), impairments are particularly consequential because of their growth demands, resulting in long-term functional deterioration, increased healthcare utilization, and reduced quality of life. Aerobic capacity, an important marker of pediatric fitness associated with adiposity and cardiovascular risk, declines notably after critical illness, causing exercise intolerance and fatigue. Muscle strength is also compromised due to systemic inflammation, excessive protein degradation, satellite-cell dysfunction, myosin loss, and fiber-type shifts from Type I to Type II, reducing endurance. Although tools such as the Medical Research Council (MRC) scale, ICU Mobility Scale (IMS), handgrip dynamometry, and the Six-Minute Walk Test (6MWT) exist, most were designed for adults, and no consensus identifies the most appropriate methods for children. This gap leads to the research question: What are the characteristics of aerobic capacity and muscle strength in children from birth to 18 years after PICU hospitalization? A scoping review is proposed to identify measurement tools used previously to assess aerobic capacity and muscle strength in pediatric PICU survivors. This is essential to avoid relying on adult-based evidence and to develop safe, effective, age-appropriate rehabilitation protocols. PICS-p includes physical, cognitive, mental, and social sequelae. Although PICU mortality is low (2.4–4.0%), survivors often experience neurocognitive and psychological complications, including ADHD in 9–50% of cases, especially after stays longer than seven days or mechanical ventilation. Physical deconditioning affects multiple systems. Cardiopulmonary alterations include elevated resting heart rate, exaggerated heart-rate response during activity, shorter diastolic time, reduced left ventricular ejection fraction, restrictive lung patterns, and ventilation/perfusion mismatch. Musculoskeletal effects include atrophy, reduced flexibility, joint stiffness, mitochondrial dysfunction, and loss of functional capacity; key affected muscles include the psoas, quadriceps, and hamstrings. Immobility may cause 2–4% muscle loss per day in adults and similar rapid loss in children, including >11% diaphragm thinning and 1.5% daily quadriceps loss. Nearly half of pediatric patients develop diaphragmatic atrophy after >48 hours of mechanical ventilation. Neurological effects include axonal transport dysfunction and peripheral neuropathy. The study is based on the biopsychosocial model, which views health as the interaction of biological, psychological, and social factors. PICS, conceptualized in 2012, encompasses physical dysfunction, cognitive impairment, psychological distress, chronic inflammation, immune suppression, and persistent catabolism. Aerobic capacity refers to the maximal ability of the pulmonary and cardiovascular systems to deliver oxygen to muscles, typically measured through VO₂max during progressive cardiopulmonary exercise testing. Muscle strength is the ability of a muscle group to generate maximum force and is necessary for daily activities. General Objective: To determine the characteristics of aerobic capacity and muscle strength in children from birth to 18 years after PICU stays. Specific Objectives: To identify validated tools used to measure aerobic capacity and muscle strength in this population. To describe the ages of the pediatric populations assessed after PICU stays. Methodology: A scoping review following the Joanna Briggs Institute (JBI) framework and PRISMA-ScR guidelines will be conducted. The protocol is registered in OSF. The PCC framework defines the population (newborns–18 years), concept (aerobic capacity and muscle strength), and context (post-PICU). Searches will be conducted in PubMed, ProQuest, Scopus, SciELO, and gray literature. Inclusion criteria include studies up to 2025 in English, Spanish, or Portuguese involving pediatric patients and reporting measurement tools. Exclusion criteria include prematurity and studies not reporting relevant instruments. A comprehensive search strategy using MeSH and DeCS terms will be adapted for each database. References will also be screened. Citations will be managed in Rayyan, with independent screening by three reviewers. Data extraction will include participant characteristics, PICU details, measurement methods, study design, context, and key findings. Discrepancies will be resolved through discussion or a fourth reviewer.