Clinical and Functional Characteristics of Patients Admitted for Severe COVID-19 Pneumonia

This study aims to evaluate the long-term impact of severe COVID-19 pneumonia on patients requiring invasive mechanical ventilation (IMV) for more than 72 hours. Specifically, it examines health-related quality of life (HRQoL), functional capacity, muscle strength, nutritional status, and work reintegration at various time points up to one year after ICU discharge. Additionally, it assesses one-year post-hospital discharge mortality and the time required for patients to return to work. The study employs a prospective, longitudinal design, following a cohort of patients aged 18 years and older discharged alive from the ICU. Participants were selected based on strict inclusion criteria, such as confirmed COVID-19 pneumonia requiring IMV for over 72 hours and the ability to provide informed consent. Exclusion criteria included cognitive impairment, prior tracheostomy, or pre-existing indications for home mechanical ventilation. The population was evaluated across four defined time points: before hospital discharge (Visit 0), at one month (Visit 1), at six months (Visit 2), and at one year post-discharge (Visit 3). Clinical, demographic, and functional data were collected through validated tools. HRQoL was assessed using the EQ-5D-3L index and visual analog scale (VAS), while functional capacity was measured with the Katz Index and the Timed Up and Go (TUG) test. Muscle strength was evaluated using the Medical Research Council (MRC) scale, and nutritional status was determined through BMI and anthropometric measurements, including arm, waist, and calf circumferences. Additional data included work reintegration and mortality outcomes, tracked through patient interviews and medical records. Data analysis employed robust statistical methods to identify trends and differences across time points. Descriptive statistics summarized demographic and baseline clinical characteristics. Longitudinal comparisons were conducted using repeated measures ANOVA or Friedman tests, with post-hoc analysis (Bonferroni or Dunn-Bonferroni) to evaluate significant pairwise differences. For comparisons involving only two time points, paired t-tests or Wilcoxon signed-rank tests were used as appropriate. All analyses adhered to a significance threshold of p \< 0.05, and data visualization was performed using SPSS and R software packages. Ethical considerations were rigorously maintained. The study was approved by the Ethics Committee of the Hospital Nacional Prof. Alejandro Posadas, and informed consent was obtained from all participants. Patient anonymity was preserved using unique coded identifiers, and all procedures complied with established guidelines for research integrity and participant safety. Preliminary results indicate significant improvements in HRQoL, functional capacity, and muscle strength over the one-year follow-up period. However, persistent challenges such as delayed work reintegration and moderate mortality rates highlight the complex recovery trajectory of critically ill COVID-19 survivors. This study underscores the importance of structured, multidisciplinary follow-up programs to address the physical, nutritional, and psychosocial needs of this vulnerable population.