Investigation of frailty markers including a novel biomarker panel in emergency laparotomy: protocol of a prospective cohort study

BACKGROUND

Emergency laparotomy (EmLAP) is one of the commonest emergency operations performed in the United Kingdom (approximately 30, 000 laparotomies annually). These potentially high-risk procedures can be life changing with frail patients and/ or older adults (≥ 65 years) having the poorest outcomes, including mortality. There is no gold standard of frailty assessment and no clinical chemical biomarkers existing in practice. Early detection of subclinical changes or deficits at the molecular level are essential in improving our understanding of the biology of frailty and ultimately improving patient outcomes. This study aims primarily to compare preoperative frailty markers, including a blood-based biomarker panel, in their ability to predict 30 and 90-day mortality post-EmLAP. The secondary aim is to analyse the influence of perioperative frailty on morbidity and quality of life post-EmLAP.

METHODS

A prospective single centred observational study will be conducted on 150 patients ≥ 40 years of age that undergo EmLAP. Patients will be included according to the established NELA (National Emergency Laparotomy Audit) criteria. The variables collected include demographics, co-morbidities, polypharmacy, place of residence, indication and type of surgery (as per NELA criteria) and prognostic NELA score. Frailty will be assessed using: a blood sample for ultra-high performance liquid chromatography mass spectrometry analysis; preoperative CT abdomen pelvis (sarcopenia) and Rockwood Clinical Frailty Scale (CFS). Patients will be followed up for 90 days. Variables collected include blood samples (at post operative day 1, 7, 30 and 90), place of residence on discharge, morbidity, mortality and quality of life (EQ-5D-5 L). The frailty markers will be compared between groups of frail (CFS ≥ 4) and non-frail using statistical methods such as regression model and adjusted for appropriate confounding factors.

DISCUSSION

This study hypothesises that frailty level changes following EmLAP in frail and non- frail patients, irrespective of age. We propose that non- frail patients will have better survival rates and report better quality of life compared to the frail. By studying the changes in metabolites/ biomarkers in these patients and correlate them to frailty status pre-surgery, this highly novel approach will develop new knowledge of frailty and define a new area of clinical biomolecular research.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT05416047. Registered on 13/06/2022 (retrospectively registered).

Magnetic field therapy enhances muscle mitochondrial bioenergetics and attenuates systemic ceramide levels following ACL reconstruction: Southeast Asian randomized-controlled pilot trial

Background

Metabolic disruption commonly follows Anterior Cruciate Ligament Reconstruction (ACLR) surgery. Brief exposure to low amplitude and frequency pulsed electromagnetic fields (PEMFs) has been shown to promote in vitro and in vivo murine myogeneses via the activation of a calcium–mitochondrial axis conferring systemic metabolic adaptations. This randomized-controlled pilot trial sought to detect local changes in muscle structure and function using MRI, and systemic changes in metabolism using plasma biomarker analyses resulting from ACLR, with or without accompanying PEMF therapy.

Methods

20 patients requiring ACLR were randomized into two groups either undergoing PEMF or sham exposure for 16 weeks following surgery. The operated thighs of 10 patients were exposed weekly to PEMFs (1 ​mT for 10 ​min) for 4 months following surgery. Another 10 patients were subjected to sham exposure and served as controls to allow assessment of the metabolic repercussions of ACLR and PEMF therapy. Blood samples were collected prior to surgery and at 16 weeks for plasma analyses. Magnetic resonance data were acquired at 1 and 16 weeks post-surgery using a Siemens 3T Tim Trio system. Phosphorus (³¹P) Magnetic Resonance Spectroscopy (MRS) was utilized to monitor changes in high-energy phosphate metabolism (inorganic phosphate (P_i), adenosine triphosphate (ATP) and phosphocreatine (PCr)) as well as markers of membrane synthesis and breakdown (phosphomonoesters (PME) and phosphodiester (PDE)). Quantitative Magnetization Transfer (qMT) imaging was used to elucidate changes in the underlying tissue structure, with T1-weighted and 2-point Dixon imaging used to calculate muscle volumes and muscle fat content.

Results

Improvements in markers of high-energy phosphate metabolism including reductions in ΔP_i/ATP, P_i/PCr and (P_i ​+ ​PCr)/ATP, and membrane kinetics, including reductions in PDE/ATP were detected in the PEMF-treated cohort relative to the control cohort at study termination. These were associated with reductions in the plasma levels of certain ceramides and lysophosphatidylcholine species. The plasma levels of biomarkers predictive of muscle regeneration and degeneration, including osteopontin and TNNT1, respectively, were improved, whilst changes in follistatin failed to achieve statistical significance. Liquid chromatography with tandem mass spectrometry revealed reductions in small molecule biomarkers of metabolic disruption, including cysteine, homocysteine, and methionine in the PEMF-treated cohort relative to the control cohort at study termination. Differences in measurements of force, muscle and fat volumes did not achieve statistical significance between the cohorts after 16 weeks post-ACLR.

Conclusion

The detected changes suggest improvements in systemic metabolism in the post-surgical PEMF-treated cohort that accords with previous preclinical murine studies. PEMF-based therapies may potentially serve as a manner to ameliorate post-surgery metabolic disruptions and warrant future examination in more adequately powered clinical trials.

The Translational Potential of this Article

Some degree of physical immobilisation must inevitably follow orthopaedic surgical intervention. The clinical paradox of such a scenario is that the regenerative potential of the muscle mitochondrial pool is silenced. The unmet need was hence a manner to maintain mitochondrial activation when movement is restricted and without producing potentially damaging mechanical stress. PEMF-based therapies may satisfy the requirement of non-invasively activating the requisite mitochondrial respiration when mobility is restricted for improved metabolic and regenerative recovery.