Chronic critical illness after hypothermia in trauma patients

Definitions, epidemiology, and outcomes of persistent/chronic critical illness: a scoping review for translation to clinical practice

BACKGROUND

Medical advances in intensive care units (ICUs) have resulted in the emergence of a new patient population-those who survive the initial acute phase of critical illness, but require prolonged ICU stays and develop chronic critical symptoms. This condition, often termed Persistent Critical Illness (PerCI) or Chronic Critical Illness (CCI), remains poorly understood and inconsistently reported across studies, resulting in a lack of clinical practice use. This scoping review aims to systematically review and synthesize the existing literature on PerCI/CCI, with a focus on definitions, epidemiology, and outcomes for its translation to clinical practice.

METHODS

A scoping review was conducted using MEDLINE and Scopus, adhering to the PRISMA-ScR guidelines. Peer-reviewed original research articles published until May 31, 2024 that described adult PerCI/CCI in their definitions of patient populations, covariates, and outcomes were included. Data on definitions, epidemiology, and outcomes were extracted by a data charting process from eligible studies and synthesized.

RESULTS

Ninety-nine studies met the inclusion criteria. Of these studies, 64 used the term CCI, 18 used PerCI, and 17 used other terms. CCI definitions showed greater variability, while PerCI definitions remained relatively consistent, with an ICU stay ≥ 14 days for CCI and ≥ 10 days for PerCI being the most common. A meta-analysis of the prevalence of PerCI/CCI among the denominators of "all ICU patients", "sepsis", "trauma", and "COVID-19" showed 11% (95% confidence interval 10-12%), 28% (22-34%), 24% (15-33%), and 35% (20-50%), respectively. A meta-analysis of in-hospital mortality was 27% (26-29%) and that of one-year mortality was 45% (32-58%). Meta-analyses of the prevalence of CCI and PerCI showed 17% (16-18%) and 18% (16-20%), respectively, and those for in-hospital mortality were 28% (26-30%) and 26% (24-29%), respectively. Functional outcomes were generally poor, with many survivors requiring long-term care.

CONCLUSIONS

This scoping review synthesized many studies on PerCI/CCI, highlighting the serious impact of PerCI/CCI on patients' long-term outcomes. The results obtained underscore the need for consistent terminology with high-quality research for PerCI/CCI. The results obtained provide important information to be used in discussions with patients and families regarding prognosis and care options.

The injured monocyte: The link to chronic critical illness and mortality following injury

BACKGROUND

This study aimed to understand the altered innate immune response in severely injured patients leading to chronic critical illness (CCI). Specifically, it focused on characterizing the monocyte populations and their correlation with CCI development and long-term complications.

METHODS

Over a 3-year period, we monitored patients with severe injuries for up to 1-year postinjury. Chronic critical illness was defined as an ICU stay exceeding 14 days with persistent organ failure. Blood samples were collected on Days 1 and 5 for monocyte phenotypic expression analysis using cytometry by time flight. The monocyte subpopulations studied were classical (CL), intermediate (INT), and nonclassical (NC), along with cell surface receptor expression and activation.

RESULTS

Out of 80 enrolled patients, 26 (32.5%) developed CCI. Patients with CCI had more severe injuries (Injury Severity Score, 32.4 + 5.2 vs. 29.6 + 4.1, p = 0.01) and received a higher number of red blood cells (8.9 + 4.1 vs. 4.7 + 3.8 units, p < 0.01) compared with those without CCI. In patients with CCI, the NC monocytes were significantly reduced by over twofold early, and significantly increased later, compared with those without CCI. Moreover, significant changes in intracellular cytokine expression and cell receptors were observed within each monocyte subpopulation in patients with CCI, indicating an increased proinflammatory phenotype but decreased phagocytic capacity and antigen presentation. The development of CCI and the presence of this unique monocyte phenotype were associated with a significantly increased risk of infection, discharge to a long-term care facility, and 1-year mortality of 27%.

CONCLUSION

Development of CCI following severe injury is associated with significant long-term morbidity and unacceptably high mortality. The altered NC phenotype with reduced phagocytic capacity and antigen presentation in patients developing CCI after severe injury is appears partially responsible. Early identification of this unique phenotype may help predict and treat patients at risk for CCI, leading to improved outcomes.

LEVEL OF EVIDENCE

Prognostic and Epidemiological; Level III.