Dr. Finn Dolan Cogswell, MD BSc
ABSTRACT
Background: The predominantly geriatric syndrome of frailty can result from the gradual reduction of function in multiple physiologic systems that occurs with increasing age. Critical illness accelerates the age-related loss of muscle that often accompanies frailty, and the combination of these two conditions creates a distinctly morbid state of vulnerability. Muscle wasting while in the intensive care unit (ICU) results in greater patient morbidity, making the preservation of muscle mass an important therapeutic target. This article narratively reviews the drug therapies that have been trialed for mitigating muscle wasting in older critically ill patients.
Materials and Methods: MEDLINE, PubMed, Web of Science and EMBASE were searched. Inclusion criteria were drug trials with muscle-related outcome measures in critically ill populations aged 50 or older. Exclusion criteria were non-pharmacological interventions, a lack of muscle related outcomes, review articles, case studies, case series and non-English articles.
Results: From 4586 identified articles, 27 articles were included in the final review. While burn populations benefitted from oxandrolone, the only pharmacotherapy that demonstrated an improvement of muscle outcomes in older general ICU patients was intensive insulin therapy. However, due to the risk of hypoglycaemia, the use of intensive insulin therapy remains largely unfavourable.
Discussion: The requirement for an effective drug therapy targeting the preservation of muscle mass in older ICU populations remains unfulfilled. Several novel drug therapies targeting myostatin and activin receptors have recently been studied in frail, non-critically ill populations. Future research should focus on studying novel pharmacotherapies in the frail and critically ill.