Computed tomography abbreviated assessment of sarcopenia following trauma: The CAAST measurement predicts 6-month mortality in older adult trauma patients

Effectiveness of sarcopenia screening markers in predicting out-of-hospital death in the oldest (≥80 years) older

OBJECTIVE

The goal of this investigation was to elucidate the correlation between sarcopenia screening indicators (aspartate transaminase/alanine transaminase (AST/ALT) and creatinine/cystatin C*100 (Cr/CysC*100)) and the risk of out-of-hospital (OFH) death among the very advanced age (≥80 years) population.

METHODS

We conducted a retrospective cohort investigation, involving internal medicine inpatients aged ≥80 years of age, who sought treatment at a teaching hospital in western China. We obtained OFH mortality information from telephonic interviews. Subsequently, we employed Cox proportional hazards models to analyze the links between AST/ALT and Cr/CysC*100 and OFH all-cause mortality among the very advanced age (≥80 years old) population.

RESULTS

In all, we recruited 398 subjects, among which 51.51% were male. The median age of OFH deceased male patients was 85 years, and the same for female patients was 87 years. The total quantity of OFH deaths was 164 (41.21%). Among the oldest male population, those who died OFH exhibited enhanced AST/ALT, relative to those who survived (death vs. survival: 1.5 vs 1.3, P=0.008). However, among the oldest female, there was no difference in AST/ALT between patients who expired OFH, and those who survived. Among the oldest elders (male and female), Cr/CysC*100 did not significantly differ between surviving and OFH deceased patients. Additional analysis involving the Cox proportional hazards model revealed that among the oldest male population, an enhanced AST/ALT denoted an augmented risk of OFH death (hazard ratios (HRs) =1.797, 95%CI: 1.2-2.691). However, Cr/CysC*100 was not correlated with OFH mortality risk. Among the oldest female population, neither AST/ALT nor Cr/CysC*100 was correlated with OFH mortality risk.

CONCLUSIONS

Enhanced AST/ALT was correlated with an augmented OFH mortality risk among the oldest male, but not female population. Alternately, Cr/CysC*100 was not linked to OFH mortality risk among any population.

Body composition parameters in initial CT imaging of mechanically ventilated trauma patients: Single-centre observational study

BACKGROUND

Body composition parameters provide relevant prognostic significance in critical care cohorts and cancer populations. Published results regarding polytrauma patients are inconclusive to date. The goal of this study was to analyse the role of body composition parameters in severely injured trauma patients.

METHODS

All consecutive patients requiring emergency tracheal intubation and mechanical ventilation before initial computed tomography (CT) at a level-1 trauma centre over a 12-year period (2008-2019) were reanalysed. The analysis included CT-derived body composition parameters based upon whole-body trauma CT as prognostic variables for 30-day mortality, intensive care unit length of stay (ICU LOS) and mechanical ventilation duration.

RESULTS

Four hundred seventy-two patients (75% male) with a median age of 49 years, median injury severity score of 26 and 30-day mortality rate of 22% (104 patients) met the inclusion criteria and were analysed. Regarding body composition parameters, 231 patients (49%) had visceral obesity, 75 patients had sarcopenia (16%) and 35 patients had sarcopenic obesity (7.4%). After adjustment for statistically significant univariable predictors age, body mass index, sarcopenic obesity, visceral obesity, American Society of Anesthesiologists classification ≥3, injury severity score and Glasgow Coma Scale ≤ 8 points, the Cox proportional hazard model identified sarcopenia as significant prognostic factor of 30-day mortality (hazard ratio 2.84; 95% confidence interval 1.38-5.85; P = 0.004), which was confirmed in Kaplan-Meier survival analysis (log-rank P = 0.006). In a subanalysis of 363 survivors, linear multivariable regression analysis revealed no significant associations of body composition parameters with ICU LOS and duration of mechanical ventilation.

CONCLUSIONS

In a multivariable analysis of mechanically ventilated trauma patients, CT-defined sarcopenia was significantly associated with 30-day mortality whereas no associations of body composition parameters with ICU LOS and duration of mechanical ventilation were observed.

Severe trauma leads to sustained muscle loss, induced frailty, and distinct temporal changes in myokine and chemokine profiles of older patients

INTRODUCTION

Sarcopenia is a known risk factor for adverse outcomes across multiple disease states, including severe trauma. Factors such as age, hyperinflammation, prolonged immobilization, and critical illness may not only exacerbate progression of this disease but may also contribute to the development of induced sarcopenia, or sarcopenia secondary to hospitalization. This study seeks to (1) determine the effects of severe traumatic injury on changes in skeletal muscle mass in older adults; (2) test whether changes in skeletal muscle mass are associated with clinical frailty, physical performance, and health-related quality of life; and (3) examine trauma-induced frailty and temporal changes in myokine and chemokine profiles.

METHODS

A prospective, longitudinal cohort study of 47 critically ill, older (≥45 years) adults presenting after severe blunt trauma was conducted. Repeated measures of computed tomography-based skeletal muscle index, frailty, and quality of life were obtained in addition to selected plasma biomarkers over 6 months.

RESULTS

Severe trauma was associated with significant losses in skeletal muscle mass and increased incidence of sarcopenia from 36% at baseline to 60% at 6 months. Severe trauma also was associated with a transient worsening of induced frailty and reduced quality of life irrespective of sarcopenia status, which returned to baseline by 6 months after injury. Admission biomarker levels were not associated with skeletal muscle index at the time points studied but demonstrated distinct temporal changes across our entire cohort.

CONCLUSIONS

Severe blunt trauma in older adults is associated with increased incidence of induced sarcopenia and reversible induced frailty. Despite muscle wasting, functional decline is transient, with a return to baseline by 6 months, suggesting a need for holistic definitions of sarcopenia and further investigation into long-term functional outcomes in this population.

Epicardial adipose tissue defined by initial polytrauma CT of mechanically ventilated trauma patients: retrospective single-center cohort study to predict short-term outcomes

PURPOSE

Epicardial adipose tissue (EAT) detected by computed tomography (CT) is associated with morbidity and mortality in patients with COVID-19 and other critical care patient cohorts, whereas their prognostic relevance in trauma patients remains unclear. The present study explored associations with four potential short-term outcomes in trauma patients.

METHODS

All consecutive trauma patients requiring emergency tracheal intubation and mechanical ventilation before initial whole-body CT imaging at a level-1 trauma center over a 12-year period (2008-2019) were reanalyzed for this study. EAT was measured semiquantitatively in initial CT and analyzed regarding associations with 24-hour and 30-day mortality using Cox proportional hazard models. In survivors, associations of EAT with intensive care unit length of stay (ICU LOS) and mechanical ventilation duration were analyzed using linear regression analyses.

RESULTS

Four hundred fifty-five patients (74.7% male) with a median age of 49 years, and a median injury severity score (ISS) of 26 points were analyzed. In univariable analysis, EAT index was significantly associated with 24-hour and 30-day mortality (p = 0.007, and p = 0.013, respectively). After adjustment for significant predictors age, body mass index, and ISS, no significant associations were confirmed (p = 0.622, and p = 0.903, respectively). In a subanalysis of 353 survivors, EAT index was significantly associated with ICU LOS and mechanical ventilation duration in univariable analyses (p = 0.031, and p = 0.014, respectively), but not in multivariable analyses (p = 0.81 and p = 0.46, respectively).

CONCLUSION

EAT index was associated with short-term outcomes in severely injured trauma patients, which not remained significant in multivariable analysis, suggesting that its prognostic capability is limited.

Pectoralis Muscle Index as Predictor of Outcomes in Patients With Severe Blunt Chest Wall Injury

INTRODUCTION

Sarcopenia has been shown to portend worse outcomes in injured patients; however, little is known about the impact of thoracic muscle wasting on outcomes of patients with chest wall injury. We hypothesized that reduced pectoralis muscle mass is associated with poor outcomes in patients with severe blunt chest wall injury.

METHODS

All patients admitted to the intensive care unit between 2014 and 2019 with blunt chest wall injury requiring mechanical ventilation were retrospectively identified. Blunt chest wall injury was defined as the presence of one or more rib fractures as a result of blunt injury mechanism. Exclusion criteria included lack of admission computed tomography imaging, penetrating trauma, <18 y of age, and primary neurologic injury. Thoracic musculature was assessed by measuring pectoralis muscle cross-sectional area (cm2) that was obtained at the fourth thoracic vertebral level using Slice-O-Matic software. The area was then divided by the patient height in meters2 to calculate pectoralis muscle index (PMI) (cm2/m2). Patients were divided into two groups, 1) the lowest gender-specific quartile of PMI and 2) second-fourth gender-specific PMI quartiles for comparative analysis.

RESULTS

One hundred fifty-three patients met the inclusion criteria with a median (interquartile range) age 48 y (34-60), body mass index of 30.1 kg/m2 (24.9-34.6), and rib score of 3.0 (2.0-4.0). Seventy-five percent of patients (116/153) were male. Fourteen patients (8%) had prior history of chronic lung disease. Median (IQR) intensive care unit length-of-stay and duration of mechanical ventilation (MV) was 18.0 d (13.0-25.0) and 15.0 d (10.0-21.0), respectively. Seventy-three patients (48%) underwent tracheostomy and nine patients (6%) expired during hospitalization. On multivariate linear regression, reduced pectoralis muscle mass was associated with increased MV duration when adjusting for rib score and injury severity score (β 5.98, 95% confidence interval 1.28-10.68, P = 0.013).

CONCLUSIONS

Reduced pectoralis muscle mass is associated with increased duration of MV in patients with severe blunt chest wall injury. Knowledge of this can help guide future research and risk stratification of critically ill chest wall injury patients.

The 2023 WSES guidelines on the management of trauma in elderly and frail patients

BACKGROUND

The trauma mortality rate is higher in the elderly compared with younger patients. Ageing is associated with physiological changes in multiple systems and correlated with frailty. Frailty is a risk factor for mortality in elderly trauma patients. We aim to provide evidence-based guidelines for the management of geriatric trauma patients to improve it and reduce futile procedures.

METHODS

Six working groups of expert acute care and trauma surgeons reviewed extensively the literature according to the topic and the PICO question assigned. Statements and recommendations were assessed according to the GRADE methodology and approved by a consensus of experts in the field at the 10th international congress of the WSES in 2023.

RESULTS

The management of elderly trauma patients requires knowledge of ageing physiology, a focused triage, including drug history, frailty assessment, nutritional status, and early activation of trauma protocol to improve outcomes. Acute trauma pain in the elderly has to be managed in a multimodal analgesic approach, to avoid side effects of opioid use. Antibiotic prophylaxis is recommended in penetrating (abdominal, thoracic) trauma, in severely burned and in open fractures elderly patients to decrease septic complications. Antibiotics are not recommended in blunt trauma in the absence of signs of sepsis and septic shock. Venous thromboembolism prophylaxis with LMWH or UFH should be administrated as soon as possible in high and moderate-risk elderly trauma patients according to the renal function, weight of the patient and bleeding risk. A palliative care team should be involved as soon as possible to discuss the end of life in a multidisciplinary approach considering the patient's directives, family feelings and representatives' desires, and all decisions should be shared.

CONCLUSIONS

The management of elderly trauma patients requires knowledge of ageing physiology, a focused triage based on assessing frailty and early activation of trauma protocol to improve outcomes. Geriatric Intensive Care Units are needed to care for elderly and frail trauma patients in a multidisciplinary approach to decrease mortality and improve outcomes.

The Emerging Role and Clinical Applications of Morphomics in Diagnostic Imaging

Analytic morphomics refers to the accurate measurement of specific biological markers of human body composition in diagnostic medical imaging. The increasing prevalence of disease processes that alter body composition including obesity, cachexia, and sarcopenia has generated interest in specific targeted measurement of these metrics to possibly prevent or reduce negative health outcomes. Typical morphomic measurements include the area and density of muscle, bone, vascular calcification, visceral fat, and subcutaneous fat on a specific validated axial level in the patient's cross-sectional diagnostic imaging. A distinct advantage of these measurements is that they can be made retrospectively and opportunistically with pre-existing datasets. We provide a narrative review of the current state of art in morphomics, but also consider some potential future directions for this exciting field. Imaging based quantitative assessment of body composition has enormous potential across the breadth and scope of modern clinical practice. From risk stratification to treatment planning, and outcome assessment, all can be enhanced with the use of analytic morphomics. Moreover, it is likely that many new opportunities for personalized medicine will emerge as the field evolves. As radiologists, embracing analytic morphomics will enable us to contribute added value in the care of every patient.

Adiposity and Coagulation: Predicting Postinjury Coagulation With Advanced Imaging Analysis

INTRODUCTION

Anatomic distribution of adipose tissue has demonstrated variable associations with hypercoagulability. Utilizing a retrospective analysis of a previously enrolled prospective cohort, we assessed computed tomography (CT) scan-based anthropometric and volumetric measures of adiposity as predictors of postinjury hypercoagulability.

METHODS

Segmentation analysis of arrival CT scans in significantly injured patients at a single level-I trauma center enrolled from December 2017 to August 2021 were analyzed for anthropometric indices of waist circumference (WC) and sagittal abdominal diameter (SAD), and volumetric parameters of visceral adipose tissue, superficial/deep subcutaneous adipose tissue, psoas/paravertebral muscle volume, and abdominal wall muscle volume. Associations with thromboelastography (TEG) were explored.

RESULTS

Data from 91 patients showed strong correlations between body mass index and standard anthropometric measures of WC and SAD (P < 0.001); calculated volumes of subcutaneous adipose tissue and visceral adipose tissue (P < 0.001); and ratios of subcutaneous adipose:psoas muscle (SP ratio) and visceral adipose:psoas muscle ratio (both with P < 0.001, respectively). Correlation between TEG maximal amplitude (MA) and body mass index and SAD were not significant, with only weak correlation between TEG-MA and WC (r = 0.238, P = 0.041). Moderate but significant correlations existed between SP ratio and TEG-MA (r = 0.340, P = 0.005), but not visceral adipose:psoas muscle ratio (r = 0.159, P = 0.198). The relationship between TEG-MA and SP ratio remained significant when adjusted for injury severity score and lactate level (b = 0.302, P = 0.001).

CONCLUSIONS

SP ratio is more strongly correlated with TEG-MA than standard obesity measures, and independently predicts increasing clot strength/stability after injury. Coagulation-relevant measures of sarcopenic obesity can be measured on CT scan, and may be used to optimize thromboprophylaxis strategies for obese injured patients.

Acute Changes in Body Muscle Mass and Fat Depletion in Hospitalized Young Trauma Patients: A Descriptive Retrospective Study

Background: Loss of muscle mass, and its strength, is associated with adverse outcomes in many medical and surgical conditions. Trauma patients may get malnourished during their hospital course due to many interrelated contributing factors. However, there is insufficient knowledge on the acute muscle and fat changes in young trauma patients in the early days post-admission. Objective: to explore the diagnosis, feeding status, and outcome of muscle mass loss among young abdominal polytrauma patients. Methods: It was a retrospective study including hospitalized abdominal trauma patients who underwent an abdominal computerized tomographic (CT) examination initially and a follow-up one week later. CT scan-based automatic and manual analysis of the muscles and fat of the abdominal region was calculated and compared. Also, we evaluated the feeding and nutritional values to explore the adequacy of the provided calories and proteins and the potential influence of enteral feeding on the CT-based parameters for muscle loss and fat depletion. Results: There were 138 eligible subjects with a mean age of 32.8 ± 13.5 years; of them, 92% were males. Operative interventions were performed on two-thirds of the patients, including abdominal surgery (43%), orthopedic surgeries (34%), and neurosurgical procedures (8.1%). On admission, 56% received oral feeding, and this rate slightly increased to 58.4% after the first week. Enteral feed was prescribed for the remaining, except for two patients. The percentage of change in the total psoas muscle area was significantly reduced after one week of admission in patients on enteral feed as compared to those in the oral feeding group (p = 0.001). There were no statistically significant differences in the percentages of changes in the CT scan findings except for the total psoas muscle area (p = 0.001) and para-spinal muscle area (p = 0.02), which reduced significantly in the those who underwent laparotomy as compared to those who did not need laparotomy. Trauma patients who underwent emergency abdominal surgery lost muscle and fat over time. Conclusions: Loss of muscle mass and body fat is not uncommon among young trauma patients. Patients who underwent laparotomy are more likely to be affected. Further larger studies are needed to assess the specific features in the younger trauma population and how far this can be influenced by the nutrition status and its impact on the clinical outcomes. It could be early or impending stages of sarcopenia linked to trauma patients, or just acute changes in the muscle and fat, that need further investigation and follow-up after hospital discharge.

Psoas Muscle Morphology as a Sarcopenia Marker to Predict Outcomes of Geriatric Trauma Patients: A Systematic Review and Meta-analysis

Objective

To provide pooled evidence on the association between central sarcopenia and risk of mortality and/or complications among geriatric patients with moderate to severe trauma.

Methods

We conducted a systematic search in PubMed, EMBASE, and Scopus databases for relevant observational studies documenting the association of central sarcopenia with the risk of mortality and/or complications in geriatric patients with moderate to severe trauma. The studies reported computerized tomography (CT) based assessments of the psoas muscle cross-sectional area. We used a random effects model for the analysis and reported effect sizes as pooled odds ratios (ORs) or hazards ratios (HRs) along with 95% confidence intervals.

Results

We analyzed data from 13 studies and found an association between the presence of psoas muscle size reduction and the risk of in-hospital mortality (OR, 1.47; 95% CI, 1.13, 1.90). In addition, we found increased risk of mortality within 24 months of follow-up in patients with sarcopenia (HR, 2.40; 95% CI, 1.11-5.17). We found each unit increase in psoas muscle cross-sectional area to be significantly associated with reduced risk of mortality within 24 months of follow-up (HR, .92; 95% CI, .90-.95). Patients with sarcopenia also had an increased risk of complications (OR, 1.69; 95% CI, 1.08-2.63).

Conclusion

Central sarcopenia, assessed using psoas muscle morphology, among geriatric patients with moderate to severe trauma appears to be significantly associated with increased risks of mortality and complications.

Application of creatinine height index in patients with trauma for the evaluation of psoas muscle mass: A clinical validation study

BACKGROUND

The creatinine height index (CHI) is an estimate of lean body mass. We hypothesize that a modified CHI estimate using serum creatinine (sCr) levels in patients with normal renal function when performed soon after injury would reflect preinjury protein nutrition status.

METHODS

The urine CHI (uCHI) was calculated using the 24-h urine sample. The serum-derived estimated CHI (sCHI) was calculated using the sCr on admission. Correlation between abdominal computed tomography images at specific lumbar vertebral levels and total body fat and muscle content was used for comparison as an independent measurement of nutrition status unlikely to be substantially altered by trauma.

RESULTS

A total of 45 patients were enrolled, all with a significant injury burden (median injury severity score [ISS] = 25; interquartile range, 17-35). The calculated sCHI on admission was 71.0% (SD = 26.9%) and likely underestimates the CHI when compared with uCHI (mean = 112.5%, SD = 32.6%). Stratifying by degree of stress demonstrated that in a group of 23 moderately and severely stressed patients, uCHI (mean = 112.7%, SD = 5.7%) and sCHI (mean = 60.8%, SD = 1.9%) were significantly different and without correlation (r = -0.26, P = 0.91). In patients without stress, there was a significant negative correlation between sCHI and psoas muscle area (r = -0.869, P = 0.03), and in patients with severe stress there was a significant positive correlation between uCHI and psoas muscle area (r = 0.733, P = 0.016).

CONCLUSION

The CHI calculated from the initial sCr is not an appropriate estimate of uCHI in critically ill trauma patients and is not a valid measure of psoas muscle mass in this setting.

Utilizing psoas muscle cross-sectional area to predict functional outcome

Background

This study evaluated psoas muscle area (PMA) as a predictor of frailty and functional outcome in trauma patients.

Methods

The cohort included 211 trauma patients admitted to an urban level I trauma center from March 2012 to May 2014 who consented to participate in a longitudinal study and underwent abdominal-pelvic computed tomography scans during their initial evaluation. Physical component scores (PCS) of the Veterans RAND 12-Item Health Survey were administered to assess physical functionality at baseline and at 3, 6, and 12 months after injury. PMA in mm² and Hounsfield units was calculated using the Centricity PACS system. Statistical models were stratified by injury severity score (ISS), <15 or ≥15, and adjusted for age, sex, and baseline PCS. Follow-up PCS were analyzed using general linear regression models.

Results

For participants with an ISS <15, increased PMA was significantly associated with higher PCS at 3 (P = 0.008), 6 (P = 0.02), and 12 months (P = 0.002), although this relationship was not statistically significant for ISS ≥15 (P = 0.85, 0.66, 0.61).

Conclusion

For mild to moderately injured (but not seriously injured) patients, those with larger psoas muscles experience better functional outcomes after injury.

The more you have, the more you lose: Muscle mass changes in trauma patients with prolonged hospitalizations

INTRODUCTION

Sarcopenia is a clinically relevant loss of muscle mass with implications of increased morbidity and mortality in adult trauma populations.  Our study aimed to evaluate loss of muscle mass change in adult trauma patients with prolonged hospital stays.

METHODS

Retrospective analysis using institutional trauma registry to identify all adult trauma patients with hospital length of stay >14 days admitted to our Level 1 center between 2010 and 2017. All CT images were reviewed, and cross-sectional area (cm²) of the left psoas muscle was measured at the level of the third lumbar vertebral body to determine total psoas area (TPA) and Total Psoas Index (TPI) normalized for patient stature.  Sarcopenia was defined as a TPI on admission below gender specific thresholds of 5.45(cm²/m²) in men and 3.85(cm²/m²) in women.  TPA, TPI, and rates of change in TPI were then evaluated and compared between sarcopenic and non-sarcopenic adult trauma patients.

RESULTS

There were 81 adult trauma patients who met inclusion criteria. The average change in TPA was -3.8 cm² and TPI was -1.3 cm². On admission, 23% (n = 19) of patients were sarcopenic while 77% (n = 62) were not. Non-sarcopenic patients had a significantly greater change in TPA (-4.9 vs. -0.31, p<0.0001), TPI (-1.7 vs. -0.13, p<0.0001), and rate of decrease in muscle mass (p = 0.0002). 37% of patients who were admitted with normal muscle mass developed sarcopenia during admission.  Older age was the only risk factor independently associated with developing sarcopenia (OR: 1.04, 95%CI 1.00-1.08, p = 0.045).

CONCLUSION

Over a third of patients with normal muscle mass at admission subsequently developed sarcopenia with older age as the primary risk factor. Patients with normal muscle mass at admission had greater decreases in TPA and TPI, and accelerated rates of muscle mass loss compared to sarcopenic patients.

Musculus psoas major morphology - a novel predictor of mortality in elderly polytraumatized patients

INTRODUCTION

Numerous papers in different fields have already shown that CT imaging of the Musculus Psoas Major (MPM) can be used to predict patient outcome. Unfortunately, most of the methods presented in the literature are very complex and not easy to perform in the clinic. Therefore, the objectives of the study were to introduce a novel and convenient method for measuring the MPM to trauma surgeons and to prove the association between MPM morphology and mortality in elderly polytraumatized patients.

MATERIAL AND METHODS

The retrospective outcome study was conducted at our level I trauma center. All patients admitted from 2006 to 2020 were included if they (1) presented with multiple injuries (≥2 body regions) and an Injury Severity Score (ISS) ≥16, (2) were at least 65 years of age, and (3) were diagnosed using a whole-body computed tomography. Subsequently, the ratios of short-axis to long-axis of both MPM were measured, and their mean value was evaluated as a candidate predictor of 31-day mortality.

RESULTS

Our study group consisted of 158 patients (63.3% male; median age, 76 years; median ISS, 25). In the survivors (55.7%), the mean MPM score was significantly higher compared to the fatalities (0.57 versus 0.48; p < 0.0001). Multivariate binary logistic regression analysis identified the MPM score as a protective predictor of 31 day-mortality (OR = 0.92, p < 0.001), whereas age (OR 1.08, p = 0.002 and ISS (OR 1.06, p = 0.006) revealed as significant risk factors for mortality. ROC statistics provided an AUC = 0.724 (p < 0.0001) and a cut-off level of 0,48 (sensitivity, 80.7%; specificity, 54.3%).

CONCLUSION

The present study demonstrated that MPM score levels lower than 0.48 might be considered an additional tool to identify elderly patients at high risk of death following major trauma. In our opinion, the assessment of the MPM score is an easy, convenient, and intuitive method to gain additional information quickly after admission to the hospital that could be implemented without great effort into daily clinical practice.

Deep learning for automatic segmentation of paraspinal muscle on computed tomography

BACKGROUND

Muscle quantification is an essential step in sarcopenia evaluation.

PURPOSE

To develop and evaluate an automated machine learning (ML) algorithm for segmenting the paraspinous muscles on either abdominal or lumbar (L) computed tomography (CT) scans.

MATERIAL AND METHODS

A novel deep neural network algorithm for automated segmentation of paraspinous muscle was developed, CT scans of 504 consecutive patients conducted between January 2019 and February 2020 were assembled. The muscle was manually segmented at L3 vertebra level by three radiologists as ground truth, divided into training and testing subgroups. Muscle cross-sectional area (CSA) was recorded. Dice similarity coefficients (DSCs) and CSA errors were calculated to evaluate system performance. The degree of muscle fat infiltration (MFI) recording by percentage value was the fat area within the region of interest divided by the muscle area. An analysis of the factors influencing the performance of the V-net-based segmentation system was also implemented.

RESULTS

The mean DSCs for paraspinous muscles were high for both the training (0.963, 0.970, 0.941, and 0.968, respectively) and testing (0.950, 0.960, 0.929, and 0.961, respectively) datasets, while the CSA errors were low for both training (1.9%, 1.6%, 3.1%, and 1.3%, respectively) and testing (3.4%, 3.0%, 4.6%, and 1.9%, respectively) datasets. MFI and muscle area index (MI) were major factors affecting DSCs of the posterior paraspinous and paraspinous muscle groups.

CONCLUSION

The ML algorithm for the measurement of paraspinous muscles was compared favorably to manual ground truth measurements.

Sarcopenia Is Associated With Increased Mortality in Patients With Necrotizing Soft Tissue Infections

INTRODUCTION

Necrotizing soft tissue infections (NSTIs) are surgical emergencies associated with high morbidity and mortality. Identifying risk factors for poor outcome is a critical part of preoperative decision-making and counseling. Sarcopenia, the loss of lean muscle mass, has been associated with an increased risk of mortality and can be measured using cross-sectional imaging. Our aim was to determine the impact of sarcopenia on mortality in patients with NSTI. We hypothesized that sarcopenia would be associated with an increased risk of mortality in patients with NSTI.

METHODS

This is a retrospective cohort study of NSTI patients admitted from 1995 to 2015 to two academic institutions. Operative and pathology reports were reviewed to confirm the diagnosis in all cases. Average bilateral psoas muscle cross-sectional area at L4, normalized for height (Total Psoas Index [TPI]), was calculated using computed tomography (CT). Sarcopenia was defined as TPI in the lowest sex-specific quartile. Primary outcome was in-hospital mortality. Multivariate logistic regression was performed to assess the association between sarcopenia and in-hospital mortality.

RESULTS

There were 115 patients with preoperative imaging, 61% male and a median age of 57 y interquartile range (IQR 46.6-67.0). Overall in-hospital mortality was 12.1%. There was no significant difference in sex, body mass index (BMI), comorbidities and American Society of Anesthesiologists classification (Table 1). After multivariate analysis, sarcopenia was independently associated with increased in-hospital mortality (Odds ratio, 3.5; 95% Confidence Interval [CI], 1.05-11.8).

CONCLUSIONS

Sarcopenia is associated with increased risk of in-hospital mortality in patients with NSTIs. Sarcopenia identifies patients with higher likelihood of poor outcomes, which can possibly help surgeons in counseling their patients and families.

Acute post-traumatic muscle atrophy on CT scan predicts prolonged mechanical ventilation and a worse outcome in severe trauma patients

BACKGROUND

The aim of present study was to assess the association between acute post-traumatic atrophy (APTMA) determined on psoas computed tomography [CT] scan and the duration of mechanical ventilation and outcomes in severe trauma patients.

METHODS

A retrospective analysis of severe trauma patients (Injury Severity Score [ISS], >15) hospitalized in the intensive care unit (ICU) for more than 7 days between January 2010 and December 2015 was performed. The psoas muscle index (PMI) was measured on admission and at delayed CT scan. ΔPMI was calculated as the percentage PMI loss between these two scans. Three groups were defined and compared a posteriori using the quartiles of the ΔPMI values: low (lower quartile), moderate, and severe (higher quartile) APTMA groups. Linear regression analysis was performed to predict the duration of mechanical ventilation, of catecholamines, length of stay (LOS) in the ICU and hospital, and complications were assessed.

RESULTS

A total of 114 trauma patients were included (median age, 40 years; [IQR, 25-54 years]; ISS, 33 [IQR, 25-41]). Based on the ΔPMI determination, 29 patients were allocated in the low APTMA group (range ∆PMI, 0%-6%), 56 in the moderate APTMA group (range ∆PMI, 6%-18%), and 29 in the APTMA group (range ∆PMI, ≥19%). Severity of APTMA was significantly associated with the duration of mechanical ventilation and catecholamines, ICU and hospital LOS (P<0.001). Delayed pneumonia (P=0.006) and other delayed infections (P=0.014), as well as thromboembolic events (P=0.04) were statistically associated with the severity of APTMA, whereas mortality did not differ between the three groups (P=0.20). Using linear regression analysis, each ∆PMI increase of 1% was significantly associated with 0.90 supplementary days of mechanical ventilation (P<0.001), 0.29 supplementary days of catecholamines (P<0.001) and 0.82 supplementary days of hospitalization (P<0.001). All these statistical associations were confirmed in multivariate analysis (P<0.001).

CONCLUSION

Acute muscle atrophy diagnosed on CT scan by psoas area measurement (ΔPMI) was strongly associated with poor outcomes in severe trauma patients.

Predicting mortality in elderly trauma patients: a review of the current literature

PURPOSE OF REVIEW

Advances in medical care allow patients to live longer, translating into a larger geriatric patient population. Adverse outcomes increase with older age, regardless of injury severity. Age, comorbidities, and physiologic deterioration have been associated with the increased mortality seen in geriatric trauma patients. As such, outcome prediction models are critical to guide clinical decision making and goals of care discussions for this population. The purpose of this review was to evaluate the various outcome prediction models for geriatric trauma patients.

RECENT FINDINGS

There are several prediction models used for predicting mortality in elderly trauma patients. The Geriatric Trauma Outcome Score (GTOS) is a validated and accurate predictor of mortality in geriatric trauma patients and performs equally if not better to traditional scores such as the Trauma and Injury Severity Score. However, studies recommend medical comorbidities be included in outcome prediction models for geriatric patients to further improve performance.

SUMMARY

The ideal outcome prediction model for geriatric trauma patients has not been identified. The GTOS demonstrates accurate predictive ability in elderly trauma patients. The addition of medical comorbidities as a variable in outcome prediction tools may result in superior performance; however, additional research is warranted.

The associations of psoas and masseter muscles with sarcopenia and related adverse outcomes in older trauma patients: a retrospective study

Background

There is an emerging role for radiological evaluation of psoas muscle as a marker of sarcopenia in trauma patients. Older trauma patients are more likely to undergo cranial than abdomino-pelvic imaging. Identifying sarcopenia using masseter cross-sectional area (M-CSA) has shown correlation with mortality. We sought to determine the correlation between psoas: lumbar vertebral index (PLVI) and the M-CSA, and their association with health outcomes.

Methods

Patients aged 65 or above, who presented as a trauma call over a 1-year period were included if they underwent cranial or abdominal CT imaging. Images were retrospectively analysed to obtain PLVI and mean M-CSA measurements. Electronic records were abstracted for outcomes. Logistic regression methods, log scale analyses, Cox regression model and Kaplan–Meier plots were used to determine association of sarcopenia with outcomes.

Results

There were 155 eligible patients in the M-CSA group and 204 patients in the PLVI group. Sarcopenia was defined as the lowest quartile in each group. Pearson’s correlation indicated a weakly positive linear relationship (r = 0.35, p < 0.001) between these. There was no statistical association between M-CSA sarcopenia status and any measured outcomes. Those with PLVI sarcopenia were more likely to die in hospital (adjusted OR 3.38, 95% CI 1.47–9.73, p = 0.006) and at 2 years (adjusted HR 1.90, 95% CI 1.11–3.25, p = 0.02). Only 29% patients with PLVI sarcopenia were discharged home, compared with 58% without sarcopenia (p = 0.001).

Conclusion

Sarcopenia, defined by PLVI, is predictive of increased in-patient and 2-year mortality. Our study did not support prognostic relevance of M-CSA.

Musculoskeletal trauma and artificial intelligence: current trends and projections

Musculoskeletal trauma accounts for a significant fraction of emergency department visits and patients seeking urgent care, with a high financial cost to society. Diagnostic imaging is indispensable in the workup and management of trauma patients. However, diagnostic imaging represents a complex multifaceted system, with many aspects of its workflow prone to inefficiencies or human error. Recent technological innovations in artificial intelligence and machine learning have shown promise to revolutionize our systems for providing medical care to patients. This review will provide a general overview of the current state of artificial intelligence and machine learning applications in different aspects of trauma imaging and provide a vision for how such applications could be leveraged to enhance our diagnostic imaging systems and optimize patient outcomes.

Rib Fracture Mortality: Are there clues in the core?

BACKGROUND

Sarcopenia is associated with increased morbidity and mortality in the trauma patient. The primary objective of this study was to determine the relationship of psoas cross sectional area with hospital mortality in patients with rib fractures over the age of 55 years.

MATERIALS AND METHODS

We retrospectively reviewed 1223 patients presenting to a Level 1 Trauma Center between 1/1/2002 and 1/31/2019. Psoas cross sectional area was measured using a polygonal tracing tool. Patients were stratified into four quartiles based on sex-specific values.

RESULTS

There was increased in-hospital mortality for patients with a lower psoas cross sectional area (10 %, 8%, 6%, and 4%, Q1-Q4 respectively; P=0.021). The logistic regression model determined for every increase in psoas cross sectional area by 1 cm² the odds of in-hospital mortality decreased by 4%.

CONCLUSIONS

In-hospital mortality is multifactorial; however, psoas cross sectional area may provide a clue in predicting adverse outcomes after traumatic rib fractures.

Handgrip strength as a valid practical tool to screen early-onset sarcopenia in acute care wards: a first evaluation

BACKGROUND/OBJECTIVES

Sarcopenia is an age-related muscle disease associated with higher mortality, morbidity risk and health costs. An easy and convenient sarcopenia screening test would be hugely valuable for clinical critical care. The study aimed to assess handgrip strength (HGS) as a screening tool for sarcopenia in acute care-unit inpatients, using the EWGSOP 1 reference-standard definition.

SUBJECTS/METHODS

Inpatients, aged 75 years old or above, of two acute care wards-a multidisciplinary care unit (MCU) and a geriatric care unit (GCU), were included between September 2017 and June 2018 in a cross-sectional study. HGS, sarcopenia, nutritional status, functional status, number of medications and sociodemographic data were collected. The accuracy of HGS as a screening test for sarcopenia was assessed by gender using receiver operating characteristic (ROC) curves and area under the curve (AUC) in a population of older patients (n = 223; age: 85.8 yrs; BMI: 26.7 kg/m²).

RESULTS

Screening was positive (patients confirmed with sarcopenia by the HGS test) with cut-off values of 18 kg for women and 25.5 kg for men, with ROC analysis giving a sensitivity of 92.9% in women and 78.6% in men. ROC curve analysis found also that HGS should be strictly higher than 15 kg in women and 18 kg in men to maximise AUC. Prevalence of sarcopenia according to the EWGSOP1 definition was 31.8% (95% CI: 22.1-41.6%) in the MCU and 27.8% (95% CI: 19.6-36.0%) in the GCU.

CONCLUSIONS

Acute care wards can use HGS as a valid, easy tool for early screening of sarcopenia.

Systematic review and meta-analysis of lean mass and mortality: Rationale and study description

Objectives

Muscle mass is one of the key components in defining sarcopenia and is known to be important for locomotion and body homeostasis. Lean mass is commonly used as a surrogate of muscle mass and has been shown to be associated with increased mortality. However, the relationship of lean mass with mortality may be affected by different clinical conditions, modalities used, cut-off point to define low or normal lean mass, and even types of cancer among cancer patients. Thus, we aim to perform a comprehensive meta-analysis of lean mass with mortality by considering all these factors.

Methods

Systematic search was done in PubMed, Cochrane Library and Embase for articles related to lean mass and mortality. Lean mass measured by dual X-ray absorptiometry, bioelectrical impedance analysis, and computerized tomography were included.

Results

The number of relevant studies has increased continuously since 2002. A total of 188 studies with 98 468 people were included in the meta-analysis. The association of lean mass with mortality was most studied in cancer patients, followed by people with renal diseases, liver diseases, elderly, people with cardiovascular disease, lung diseases, and other diseases. The meta-analysis can be further conducted in subgroups based on measurement modalities, site of measurements, definition of low lean mass adopted, and types of cancer for studies conducted in cancer patients.

Conclusions

This series of meta-analysis provided insight and evidence on the relationship between lean mass and mortality in all directions, which may be useful for further study and guideline development.

Automated Muscle Measurement on Chest CT Predicts All-Cause Mortality in Older Adults From the National Lung Screening Trial

BACKGROUND

Muscle metrics derived from computed tomography (CT) are associated with adverse health events in older persons, but obtaining these metrics using current methods is not practical for large datasets. We developed a fully automated method for muscle measurement on CT images. This study aimed to determine the relationship between muscle measurements on CT with survival in a large multicenter trial of older adults.

METHOD

The relationship between baseline paraspinous skeletal muscle area (SMA) and skeletal muscle density (SMD) and survival over 6 years was determined in 6,803 men and 4,558 women (baseline age: 60-69 years) in the National Lung Screening Trial (NLST). The automated machine learning pipeline selected appropriate CT series, chose a single image at T12, and segmented left paraspinous muscle, recording cross-sectional area and density. Associations between SMA and SMD with all-cause mortality were determined using sex-stratified Cox proportional hazards models, adjusted for age, race, height, weight, pack-years of smoking, and presence of diabetes, chronic lung disease, cardiovascular disease, and cancer at enrollment.

RESULTS

After a mean 6.44 ± 1.06 years of follow-up, 635 (9.33%) men and 265 (5.81%) women died. In men, higher SMA and SMD were associated with a lower risk of all-cause mortality, in fully adjusted models. A one-unit standard deviation increase was associated with a hazard ratio (HR) = 0.85 (95% confidence interval [CI] = 0.79, 0.91; p < .001) for SMA and HR = 0.91 (95% CI = 0.84, 0.98; p = .012) for SMD. In women, the associations did not reach significance.

CONCLUSION

Higher paraspinous SMA and SMD, automatically derived from CT exams, were associated with better survival in a large multicenter cohort of community-dwelling older men.

High Prevalence of Sarcopenia in Older Trauma Patients: A Pilot Study

Sarcopenia is related to adverse outcomes in various populations. However, little is known about the prevalence of sarcopenia in polytrauma patients. Identifying the number of patients at risk of adverse outcome will increase awareness to prevent further loss of muscle mass. We utilized data from a regional prospective trauma registry of all polytrauma patients presented between 2015 and 2019 at a single level-I trauma center. Subjects were screened for availability of computed tomography (CT)-abdomen and height in order to calculate skeletal mass index, which was used to estimate sarcopenia. Additional parameters regarding clinical outcome were assessed. Univariate analysis was performed to identify parameters related adverse outcome and, if identified, entered in a multivariate regression analysis. Prevalence of sarcopenia was 33.5% in the total population but was even higher in older age groups (range 60–79 years), reaching 82 % in patients over 80 years old. Sarcopenia was related to 30-day or in-hospital mortality (p = 0.032), as well as age (p < 0.0001), injury severity score (p = 0.026), and Charlson comorbidity index (p = 0.001). Log rank analysis identified sarcopenia as an independent predictor of 30-day mortality (p = 0.032). In conclusion, we observed a high prevalence of sarcopenia among polytrauma patients, further increasing in older patients. In addition, sarcopenia was identified as a predictor for 30-day mortality, underlining the clinical significance of identification of low muscle mass on a CT scan that is already routinely obtained in most trauma patients.

Approaches to Assessment of Muscle Mass and Myosteatosis on Computed Tomography: A Systematic Review

BACKGROUND/OBJECTIVE

There is increasing use of computed tomography (CT) in sarcopenia research using a wide variety of techniques. We performed a systematic review of the CT literature to identify the differences between approaches used.

METHODS

A comprehensive search of PubMed from 1983 to 2017 was performed to identify studies that used CT muscle measurements to assess muscle mass and myosteatosis. The CT protocols were evaluated based on anatomic landmark(s), thresholding, muscle(s) segmented, key measurement (ie, muscle attenuation, cross-sectional area, volume), derived variables, and analysis software. From the described search, 657 articles were identified and 388 studies met inclusion criteria for this systematic review.

RESULTS

Muscle mass was more commonly assessed than myosteatosis (330 vs. 125). The most commonly assessed muscle or muscle groups were total abdominal wall musculature (142/330 and 49/125 for muscle mass and myosteatosis, respectively) and total thigh musculature (90/330 and 48/125). The most commonly used landmark in the abdomen was the L3 vertebra (123/142 and 45/49 for muscle mass and myosteatosis, respectively). Skeletal muscle index and intermuscular adipose tissue were the most commonly used measures of abdominal wall muscle mass (114/142) and myosteatosis (27/49), respectively. Cut points varied across studies. A significant majority of studies failed to report important CT technical parameters, such as use of intravenous contrast and slice thickness (94% and 63%, respectively).

CONCLUSIONS

There is considerable variation in the CT approaches used for the assessment of muscle mass and myosteatosis. There is a need to develop consensus for CT-based evaluation of sarcopenia and myosteatosis.

A retrospective observational study of sarcopenia and outcomes in critically ill patients

Frailty assessment in patients admitted to intensive care is often limited using traditional clinical frailty assessment tools. Opportunistic use of contemporary computed tomography (CT) can provide an objective estimate of low skeletal muscle mass (sarcopenia) as a proxy for frailty. The aim of this study was to establish the prevalence of sarcopenia in an Australian intensive care unit (ICU) population and to examine the relationship between sarcopenia and clinical outcomes. We undertook a single centre retrospective study of 1085 adult patients admitted to a single ICU over 12 months. Patients with a contemporary CT scan including the L3 vertebral body were included. Patients were categorised as sarcopenic or non-sarcopenic using previously published data. A total of 279 patients with a mean age of 67 years had an eligible CT scan; 163 (58%) were male. Higher 30-day mortality was associated with the use of CRRT (continuous renal replacement therapy) during the ICU admission (OR 6.84, P < 0.001) and also associated with lower cross-sectional muscle area (odds ratio (OR) 0.98, P = 0.004). Sarcopenia was found to be highly prevalent in this particular Australian ICU population (68%) and associated with older age (68 versus 55 years, P < 0.001), lower body mass index (27 versus 32 kg m^-2, P < 0.001), more comorbidities (3 versus 2, P = 0.009), and longer stays in hospital (279 versus 223 h, P = 0.043). As a continuous predictor, lumbar muscle mass was associated with 30-day mortality with and without adjusting for other covariates.

One-year mortality in geriatric trauma patients: Improving upon the geriatric trauma outcomes score utilizing the social security death index

BACKGROUND

Geriatric Trauma Outcomes Score (GTOS) predicts in-patient mortality in geriatric trauma patients and has been validated in a prospective multicenter trial and expanded to predict adverse discharge (GTOS II). We hypothesized that these formulations actually underestimate the downstream sequelae of injury and sought to predict longer-term mortality in geriatric trauma patients.

METHODS

The Parkland Memorial Hospital Trauma registry was queried for patients 65 years or older from 2001 to 2013. Patients were then matched to the Social Security Death Index. The primary outcome was 1-year mortality. The original GTOS formula (variables of age, Injury Severity Score [ISS], 24-hour transfusion) was tested to predict 1-year mortality using receiver operator curves. Significant variables on univariate analysis were used to build an optimal multivariate model to predict 1-year mortality (GTOS III).

RESULTS

There were 3,262 patients who met inclusion. Inpatient mortality was 10.0% (324) and increased each year: 15.8%, 1 year; 17.8%, 2 years; and 22.6%, 5 years. The original GTOS equation had an area under the curve of 0.742 for 1-year mortality. Univariate analysis showed that patients with 1-year mortality had on average increased age (75.7 years vs. 79.5 years), ISS (11.1 vs. 19.1), lower GCS score (14.3 vs. 10.5), more likely to require transfusion within 24 hours (11.5% vs. 31.3%), and adverse discharge (19.5% vs. 78.2%; p < 0.0001 for all). Multivariate logistic regression was used to create the optimal equation to predict 1-year mortality: (GTOSIII = age + [0.806 × ISS] + 5.55 [if transfusion in first 24 hours] + 21.69 [if low GCS] + 34.36 [if adverse discharge]); area under the curve of 0.878.

CONCLUSION

Traumatic injury in geriatric patients is associated with high mortality rates at 1 year to 5 years. GTOS III has robust test characteristics to predict death at 1 year and can be used to guide patient centered goals discussions with objective data.

LEVEL OF EVIDENCE

Prognostic, level III.

Opportunistic Measurement of Skeletal Muscle Size and Muscle Attenuation on Computed Tomography Predicts 1-Year Mortality in Medicare Patients

BACKGROUND

Opportunistic assessment of sarcopenia on CT examinations is becoming increasingly common. This study aimed to determine relationships between CT-measured skeletal muscle size and attenuation with 1-year risk of mortality in older adults enrolled in a Medicare Shared Savings Program (MSSP).

METHODS

Relationships between skeletal muscle metrics and all-cause mortality were determined in 436 participants (52% women, mean age 75 years) who had abdominopelvic CT examinations. On CT images, skeletal muscles were segmented at the level of L3 using two methods: (a) all muscles with a threshold of -29 to +150 Hounsfield units (HU), using a dedicated segmentation software, (b) left psoas muscle using a free-hand region of interest tool on a clinical workstation. Muscle cross-sectional area (CSA) and muscle attenuation were measured. Cox regression models were fit to determine the associations between muscle metrics and mortality, adjusting for age, sex, race, smoking status, cancer diagnosis, and Charlson comorbidity index.

RESULTS

Within 1 year of follow-up, 20.6% (90/436) participants died. In the fully-adjusted model, higher muscle index and muscle attenuation were associated with lower risk of mortality. A one-unit standard deviation (SD) increase was associated with a HR = 0.69 (95% CI = 0.49, 0.96; p = .03) for total muscle index, HR = 0.67 (95% CI = 0.49, 0.90; p < .01) for psoas muscle index, HR = 0.54 (95% CI = 0.40, 0.74; p < .01) for total muscle attenuation, and HR = 0.79 (95% CI = 0.66, 0.95; p = .01) for psoas muscle attenuation.

CONCLUSION

In older adults, higher skeletal muscle index and muscle attenuation on abdominopelvic CT examinations were associated with better survival, after adjusting for multiple risk factors.

The psoas muscle index distribution and influence of outcomes in an Asian adult trauma population: an alternative indicator for sarcopenia of acute diseases

BACKGROUND

Sarcopenia has been shown to be an independent negative predictor in various diseases. The measurement of pre-defined criteria of skeletal muscle in patients with acute disease is usually unavailable. Therefore, we evaluate the psoas muscle area based on computed tomography (CT) imaging as an alternative for sarcopenia in an Asian trauma population.

METHODS

939 trauma patients were enrolled and had CT imaging performed primarily for trauma indications. The cross-sectional area of psoas muscle at the base of the fourth lumbar vertebral was measured on these CTs. Psoas muscle index (PMI) was calculated and analyzed to determine sex-specific cut-off values to define the "extremely low psoas muscle index" (ELPMI) group.

RESULTS

Psoas muscle index was significantly higher in males (1065.09 ± 230.51 mm²/m² in males vs 719.57 ± 147.39 mm²/m² in females, p < 0.001) and decreased gradually with aging (p < 0.001). PMI of the subset of patients aged 18-40 (n = 462) weas analyzed to determine sex-specific cut-off values for ELPMI. PMI cut-off values for ELPMI (2 SD below mean) were 675 mm²/m² for males and 490 mm²/m² for females. The entire trauma cohort was further analyzed, and ELPMI was identified as an independent risk factor for a longer length of intensive unit stay (β coefficient = 3.881, p = 0.011).

CONCLUSION

Data from young trauma adults were used to establish cut-off values for ELPMI, which is a longer ICU stay predictor. These cut-off values for ELPMI may apply to other acute disease entities.

Radiographic assessment of sarcopenia in the trauma setting: a systematic review

Background

Compared with similarly injured patients of a younger age, elderly patients have worse outcomes from acute injury. One factor adversely affecting outcomes is sarcopenia, which has been assessed in healthy elderly populations through established clinical and radiological criteria. However, in the acute care setting, no such criteria have been established. Sarcopenia has been opportunistically assessed via radiographic means but there is as of yet no gold standard. The purpose of this review is to summarize the radiological methods used to diagnose sarcopenia in the acute care setting, and suggest ways in which these methods may lead to a consensus definition of sarcopenia and its relationship to patient outcomes.

Methods

A systematic survey of medical databases was conducted, with 902 unique publications identified. After screening and application of inclusion and exclusion criteria, data regarding study population, outcome, imaging modality, and criteria for assessment of sarcopenia were extracted from 20 studies. Quality was assessed with the Newcastle-Ottawa Scale.

Results

CT was the imaging modality for 18 of the studies, with total psoas muscle cross-sectional area at the level of L3 and L4 being the dominant method for assessing sarcopenia. Adjustment for body morphology most commonly used patient height or L4 vertebral body area. The majority of articles found radiographically assessed sarcopenia to be significantly correlated to outcomes such as mortality, length of hospital stay, morbidity, and in-hospital complications

Conclusions

Establishing a consistent definition would strengthen its applicability and generalizability to admission and discharge planning.

Level of evidence

Systematic review, level III.

The psoas muscle index as a predictor of mortality and morbidity of geriatric trauma patients: experience of a major trauma center in Kobe

PURPOSE

An association between the prognoses of trauma and sarcopenia has not been well documented. The purpose of this study was to compare the outcomes of elderly Japanese trauma patients with sarcopenia and those without sarcopenia.

METHODS

The medical records of patients aged ≧ 65 years old and Injury Severity Scores above 15 treated for trauma between 2010 and 2017 were reviewed, retrospectively. We measured the psoas muscle index (PMI), defined as the psoas muscle area at the third lumbar vertebra level divided by the body surface area. Patients of each gender with a PMI less than the lower interquartile range were included in the sarcopenia group. A questionnaire was mailed to the patients or their families to collect data on 1-year mortality and activities of daily living.

RESULTS

There were 405 patients included in this study: 304 in the non-sarcopenia group (Group NS) and 101 in the sarcopenia group (Group S). Mortality was significantly higher in Group S than in Group NS (NS; 7.9% vs. S; 15.8%, OR, 2.20; 95% CI, 1.12-4.32; p = 0.027). Only 175 of the questionnaires were completed and the responses did not reveal any significant differences between the groups.

CONCLUSIONS

Sarcopenia as defined by the PMI may be used as an indicator for mortality risk for geriatric trauma patients.

A Machine Learning Algorithm to Estimate Sarcopenia on Abdominal CT

RATIONALE AND OBJECTIVES

To assess whether a fully-automated deep learning system can accurately detect and analyze truncal musculature at multiple lumbar vertebral levels and muscle groupings on abdominal CT for potential use in the detection of central sarcopenia.

MATERIALS AND METHODS

A computer system for automated segmentation of truncal musculature groups was designed and created. Abdominal CT scans of 102 sequential patients (mean age 68 years, range 59-81 years; 53 women, 49 men) conducted between January 2015 and February 2015 were assembled as a data set. Truncal musculature was manually segmented on axial CT images at multiple lumbar vertebral levels as reference standard data, divided into training and testing subsets, and analyzed by the system. Dice similarity coefficients were calculated to evaluate system performance. IRB approval was obtained, with waiver of informed consent in this retrospective study.

RESULTS

System performance as gauged by the Dice coefficients, for detecting the total abdominal muscle cross-section at the level of the third and fourth lumbar vertebrae, were, respectively, 0.953 ± 0.015 and 0.953 ± 0.011 for the training set, and 0.938 ± 0.028 and 0.940 ± 0.026 for the testing set. Dice coefficients for detecting total psoas muscle cross-section at the level of the third and fourth lumbar vertebrae, were, respectively, 0.942 ± 0.040 and 0.951 ± 0.037 for the training set, and 0.939 ± 0.028 and 0.946 ± 0.032 for the testing set.

CONCLUSION

This system fully-automatically and accurately segments multiple muscle groups at all lumbar spine levels on abdominal CT for detection of sarcopenia.

Assessing Low Skeletal Mass in Patients Undergoing Hip Surgery: The Role of Sonoelastography

Purpose

To analyze the utility of sonoelastography—a radiation-free procedure to characterize muscle properties—as an instrument to qualitatively and quantitatively assess the rectus femoris muscle.

Materials and Methods

Fifty-one consecutive patients who underwent a pelvic computed tomography (CT) exam were enrolled prospectively. The final analysis was conducted using data from 39 patients after 12 were removed due to exclusion criteria (muscle strength could not be measured due to poor cognition [n=11]; too young [n=1]). The potential correlation between average Hounsfield unit (HFU) at the rectus femoris muscle (measured by CT) and muscle quality grade (determined by sonoelastography) was assessed along with a retrospective analysis of the relationship between hand grip strength, knee extensor power, history of intensive care unit stay, length of hospital day and sonoelastographic grade.

Results

There was a significant correlation between sonoelastographic grade and the average HFU (P<0.001). Furthermore, hand grip strength (P<0.001) and knee extensor power (P<0.001) decreased significantly as the sonoelastographic grade increased. The likelihood of an intensive care unit stay and prevalence of low skeletal mass increased significantly with an increase in sonoelastography grade (P=0.037, P<0.001, respectively). The sensitivity, specificity, and accuracy of sonoelastographic images for predicting low skeletal mass were 77.3%, 100%, and 87.5%, respectively.

Conclusion

Sonoelastography advantages, including the lack of radiation and greater accessibility, may make it a valuable alternative to qualitatively and quantitatively identify sarcopenia and low skeletal mass.

Impact of sarcopenia in trauma and surgical patient population: A literature review

Sarcopenia refers to the progressive and generalised loss of skeletal muscle mass and strength with a risk of adverse outcomes such as physical disability, poor quality of life and mortality. The present review explored the impact, diagnosis, prevention and management of sarcopenia in surgical and trauma patients. Recent evidence suggests that there are many factors contributing to its development other than age. Pathophysiology of sarcopenia is complex which makes its diagnosis difficult and there is no universal approach. It is a predictor of poor outcomes including post-operative complications, length of hospital stay and mortality in trauma and surgery patients. Sedentary lifestyle, age-dependent hormone and cytokine imbalance, decreased protein synthesis and regeneration, and motor unit remodelling are some of the main risk factors for sarcopenia. Dual energy X-ray absorptiometry, bio-electrical impedance analysis and computed tomography are frequently utilized for its diagnosis. Management of sarcopenia involves appropriate management of comorbidities, interventions to facilitate physical activities, nutrition interventions and pharmacotherapy.

Sarcopenia is Predictive of Functional Outcomes in Older Trauma Patients

Introduction: Older patients are more vulnerable to poor outcomes after trauma than younger patients. Sarcopenia, loss of skeletal mass, is prevalent in trauma patients admitted to the intensive care unit (ICU), and it has been shown to correlate with adverse outcomes, such as mortality and ICU days. Yet, little is known whether it predicts other outcomes. We hypothesized that sarcopenia independently predicts poor functional outcomes in older trauma patients admitted to the ICU.

Methods: We performed a retrospective review of patients aged >55 admitted to a surgical ICU in a Level I trauma center for two years. Sarcopenic status was determined by measuring total skeletal muscle cross-sectional area at the L3 level on admission computed tomography (CT), normalized for height with sex-specific cutoffs. Primary outcome measures were in-hospital mortality, functional outcomes measured by the Glasgow Outcome Scale (GOS) at discharge, and discharge disposition. Multivariable logistic regression was used to determine predictors of primary outcomes.

Results: Out of 230 patients, 32% were sarcopenic. The overall mortality was 20%, and 30% were discharged with poor functional outcomes. A higher proportion of sarcopenic patients among survivors had poor functional outcomes at discharge (55% vs. 30%, p=0.002). Sarcopenia was not predictive of in-hospital mortality but was an independent predictor of poor functional outcomes at discharge (OR 2.6; 95% confidence interval [CI] 1.3-5.5), adjusting for age, Glasgow Coma Scale (GCS) on admission, diagnosis of traumatic brain injury (TBI), Injury Severity Score (ISS), and the number of life-limiting illnesses.

Conclusions: Sarcopenia is prevalent in geriatric trauma ICU patients and is an independent predictor of poor functional outcomes. Assessing for sarcopenia has an important potential as a prognostic tool in older trauma patients.

Duration of Respiratory Failure After Trauma Is Not Associated With Increased Long-Term Mortality

OBJECTIVES

Although 1-year survival in medically critically ill patients with prolonged mechanical ventilation is less than 50%, the relationship between respiratory failure after trauma and 1-year mortality is unknown. We hypothesize that respiratory failure duration in trauma patients is associated with decreased 1-year survival.

DESIGN

Retrospective cohort of trauma patients.

SETTING

Single center, level 1 trauma center.

PATIENTS

Trauma patients admitted from 2011 to 2014; respiratory failure is defined as mechanical ventilation greater than or equal to 48 hours, excluded head Abbreviated Injury Score greater than or equal to 4.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Mortality was calculated from the Washington state death registry. Cohort was divided into short (≤ 14 d) and long (> 14 d) ventilation groups. We compared survival with a Cox proportional hazard model and generated a receiver operator characteristic to describe the respiratory failure and mortality relationship. Data are presented as medians with interquartile ranges and hazard ratios with 95% CIs. We identified 1,503 patients with respiratory failure; median age was 51 years (33-65 yr) and Injury Severity Score was 19 (11-29). Median respiratory failure duration was 3 days (2-6 d) with 10% of patients in the long respiratory failure group. Cohort mortality at 1 year was 16%, and there was no difference in mortality between short and long duration of respiratory failure. Predictions for 1-year mortality based on respiratory failure duration demonstrated an area under the receiver operator characteristic curve of 0.57. We determined that respiratory failure patients greater than or equal to 75 years had an increased hazard of death at 1 year, hazard ratio, 6.7 (4.9-9.1), but that within age cohorts, respiratory failure duration did not influence 1-year mortality.

CONCLUSIONS

Duration of mechanical ventilation in the critically injured is not associated with 1-year mortality. Duration of ventilation following injury should not be used to predict long-term survival.

The impact of computed tomography-assessed sarcopenia on outcomes for trauma patients - a systematic review and meta-analysis

INTRODUCTION

Sarcopenia is the progressive loss of skeletal muscle mass, strength and general decline in function associated with age, and has previously been shown to be a predictor of poor outcomes following surgery. Computed tomography (CT)-assessed sarcopenia has been proposed to be an independent predictor of outcomes for trauma patients. This systematic review aims to determine the impact of CT-assessed sarcopenia on patient mortality following trauma.

MATERIALS AND METHODS

A systematic review and meta-analysis of the literature was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. EMBASE, MEDLINE and CENTRAL databases were searched from database inception to 26 November 2018. Bibliographies of included articles were hand searched for potential articles. All observational studies which included trauma patients who had skeletal muscle mass or density assessed by CT were included in the review. Two authors independently performed the search with decisions reached by consensus. Meta-analysis was performed using Review Manager v5.3 using a random effects model. The primary outcome was all cause mortality, as established a priori.

RESULTS

Following an initial search of 1984 records, a total of 20 retrospective observational studies were included for qualitative analysis. Ten of these studies consisting of a pooled, partly-overlapping, 2867 patients were included in the meta-analysis. There was a wide variation in the reported prevalence of sarcopenia (25.0-71.1%). Sarcopenia patients were at a significantly increased risk of mortality during inpatient stay (RR 1.96 [95%CI 1.30-2.94], p =  0.001), at 30 days (RR 1.60 [95%CI 1.21-2.13], p =  0.001) and at 1-year (RR 3.11 [95%CI 1.94-4.96], p <  0.00001). There was no significant difference in total complications encountered, ICU duration or total inpatient stay.

CONCLUSION

Sarcopenia identified by CT is associated with increased risk of inpatient, 30-day, and 1-year mortality in trauma patients.

Sarcopenia is an effective predictor of difficult-to-wean and mortality among critically ill surgical patients

BACKGROUND

Critically-ill surgical patients are at higher risk for sarcopenia, which is associated with worse survival. Sarcopenia may impair the respiratory musculature, which can subsequently influence the outcome of ventilator weaning. Although there are a variety of weaning parameters predictive of weaning outcomes, none have tried to incorporate "muscle strength" or "sarcopenia". The aim of the current study was to explore the association between sarcopenia and difficult-to-wean (DtW) in critically-ill surgical patients. The influence of sarcopenia on ICU mortality was also analyzed.

METHODS

Ninety-six patients undergoing mechanical ventilation in the surgical intensive care unit (ICU) were enrolled. Demographic data and weaning parameters were recorded from the prospectively collected database, and the total psoas muscle area (TPA) was determined at the level of the 3rd lumbar vertebra by computed tomography. Sarcopenia was defined by previously established cut-off points and its influence on clinical outcomes was examined. Receiver operating characteristic (ROC) curve analysis was conducted to investigate the predictive capability of TPA and weaning parameters for predicting weaning outcomes.

RESULTS

The median age of the studied patients was 73 years. Thirty patients (31.3%) were sarcopenic and 30 (31.3%) were defined as DtW. Eighteen patients (18.8%) had ICU mortality. Multivariate logistic regression analyses revealed that sarcopenia was an independent risk factor for DtW and ICU mortality. The area under the ROC curve (AUC) of TPA for predicting successful weaning was 0.727 and 0.720 in female and male patients, respectively. After combining TPA and conventional weaning parameters, the AUC for DtW increased from 0.836 to 0.911 and from 0.835 to 0.922 in female and male patients, respectively.

CONCLUSION

Sarcopenia is an independent risk factor for DtW and ICU mortality. TPA has predictive value when assessing weaning outcomes and can be used as an effective adjunct predictor along with conventional weaning parameters.

Frailty assessment: from clinical to radiological tools

Frailty is a syndrome of cumulative decline across multiple physiological systems, which predisposes vulnerable adults to adverse events. Assessing vulnerable patients can potentially lead to interventions that improve surgical outcomes. Anaesthesiologists who care for older patients can identify frailty to improve preoperative risk stratification and subsequent perioperative planning. Numerous clinical tools to diagnose frailty exist, but none has emerged as the standard tool to be used in clinical practice. Radiological modalities, such as computed tomography and ultrasonography, are widely performed before surgery, and are therefore available to be used opportunistically to objectively evaluate surrogate markers of frailty. This review presents the importance of frailty assessment by anaesthesiologists; lists common clinical tools that have been applied; and proposes that utilising radiological imaging as an objective surrogate measure of frailty is a novel, expanding approach for which anaesthesiologists can significantly contribute to broad implementation.

Sarcopenia predicts 90-day mortality in elderly patients undergoing emergency abdominal surgery

PURPOSE

Image-based measurement of sarcopenia is an established predictor of a decreased outcome for a large variety of surgical procedures. Sarcopenia in elderly patients undergoing emergency abdominal surgery has not been well studied. This study aims to investigate the association between the total psoas area (TPA) and postoperative mortality after 90 days in a group of elderly emergency laparotomy patients.

METHODS

We retrospectively reviewed the emergency CT-scans of 150 elderly patients from a consecutive cohort undergoing emergency abdominal surgery at our surgical center. TPA was measured manually at the level of L3 and indexed to patient height. Sarcopenia was defined as having a TPA index below the first quartile for gender in the cohort. Other collected variables were age, vital status/date of death, ASA-score, surgical procedure, and WHO performance score.

RESULTS

Overall 90-day mortality was 42.7%. Sarcopenic patients had a higher 90-day mortality (60.5%) than non-sarcopenic patients (36.6%), corresponding to an odds ratio of 2.66 (95% confidence interval 1.2-5.7, p = 0.01). Sarcopenic patients had an increased mortality compared with non-sarcopenic patients (p = 0.0009, Log-rank test), with a clear separation of the two groups within 30 days postoperatively. In a multivariate logistic regression model, with age, ASA-score, and WHO performance score as covariates, sarcopenia was independently associated with 90-day mortality.

CONCLUSION

Manual measurement of TPA on an abdominal CT-scan is a relevant risk factor for postoperative mortality in elderly patients undergoing high-risk emergency abdominal surgery. Incorporation of sarcopenia in postoperative risk-prediction models in emergency abdominal surgery should be considered.

Comparison of individual and composite radiographic markers of frailty in trauma

BACKGROUND

Clinical frailty scores usually involve questionnaires or physical testing. Many trauma patients are not able to participate in these. Radiographic measurement of frailty may be a viable alternative. Individual radiographic markers of frailty have been investigated, such as sarcopenia or osteopenia. The ideal radiographic variable (or variables) to measure frailty in trauma is unknown.

STUDY DESIGN

A retrospective review was performed of restrained drivers ages 40 and greater at a single institution from 2010-2015. Multiple markers of radiographic frailty were measured including: sarcopenia, osteopenia, vascular calcifications, sarcopenic obesity, emphysema, renal volume, cervical spine degeneration, and cerebral atrophy. Frailty was defined as the worst quartile for each radiographic variable, and these values were summed to create a composite marker of frailty. The primary outcome was discharge disposition. We hypothesized that a composite frailty score would be associated with discharge disposition while individual markers would not be associated with discharge disposition.

RESULTS

Overall 489 patients were included in this study. Cerebral atrophy (p = 0.05), renal volume (p = 0.004), sarcopenia (p = 0.05), vascular calcifications (p = 0.02) and sarcopenic obesity (p = 0.01) were associated with discharge disposition. Pearson's correlation coefficients between radiographic frailty markers were all less than 0.4. Youden's Index was 0.26 (p < 0.001) at a composite score of 3. In multivariable analysis, the composite score of 3 or greater was associated with poor discharge disposition (OR 2.39, 95% CI 1.10-5.18, p = 0.03).

CONCLUSIONS

Individual radiographic frailty markers are inadequate markers of frailty, as they may miss patients who are frail. This study also suggests that a composite radiographic frailty score may better predict patient outcome than individual radiographic markers of frailty.

Decreased Lean Psoas Cross-Sectional Area Is Associated With Increased 1-Year All-Cause Mortality in Male Elderly Orthopaedic Trauma Patients

OBJECTIVES

To investigate the association between lean psoas cross-sectional area (CSA) and 1-year all-cause mortality in elderly patients sustaining pelvic and long bone fractures.

DESIGN

Retrospective cohort.

SETTING

Level I trauma center.

PATIENTS

Elderly trauma patients admitted from 2007 to 2014.

METHODS

We reviewed demographic and clinical data, injury mechanism, fracture OTA/AO classification, and mortality. Axial computed tomography images were used to measure lean psoas CSA at the L3-L4 disk space. Cox proportional hazard regression analysis was used to estimate 1-year mortality association with psoas CSA in crude and adjusted for age, body mass index, Injury Severity Score, medical comorbidities, and discharge destination in total population and stratified by sex.

MAIN OUTCOME MEASUREMENT

One-year all-cause mortality defined as death within 12 months from date of hospitalization.

RESULTS

Five hundred fifty-eight patients (54% female, 46% male) were analyzed. The pelvis was most commonly fractured (37.81%). A statistically significant association was observed between decreased lean psoas CSA and 1-year mortality in total population {hazard ratio [HR] = 0.93 [95% confidence interval (CI) = 0.90-0.96], P < 0.0001}. Stratification by gender revealed a statistically significant mortality HR in male patients [HR = 0.89 (95% CI = 0.84-0.96), P = 0.002]. We did not find a statistically significant mortality HR in female patients [HR = 0.95 (95% CI = 0.89-1.01), P = 0.103].

CONCLUSIONS

In this cohort of elderly orthopaedic trauma patients, decreased lean psoas CSA was associated with increased 1-year all-cause mortality in total population and males. Further investigation of the association of sarcopenia with mortality in the elderly is warranted.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Implications of low muscle mass across the continuum of care: a narrative review

Abnormalities in body composition can occur at any body weight. Low muscle mass is a predictor of poor morbidity and mortality and occurs in several populations. This narrative review provides an overview of the importance of low muscle mass on health outcomes for patients in inpatient, outpatient and long-term care clinical settings. A one-year glimpse at publications that showcases the rapidly growing research of body composition in clinical settings is included. Low muscle mass is associated with outcomes such as higher surgical and post-operative complications, longer length of hospital stay, lower physical function, poorer quality of life and shorter survival. As such, the potential clinical benefits of preventing and reversing this condition are likely to impact patient outcomes and resource utilization/health care costs. Clinically viable tools to measure body composition are needed for routine screening and intervention. Future research studies should elucidate the effectiveness of multimodal interventions to counteract low muscle mass for optimal patient outcomes across the healthcare continuum. Key messages Low muscle mass is associated with several negative outcomes across the healthcare continuum. Techniques to identify and counteract low muscle mass in clinical settings are needed.

Screening for low muscularity in colorectal cancer patients: a valid, clinic-friendly approach that predicts mortality

BACKGROUND

Low skeletal muscle quantified using computed tomography (CT) scans is associated with morbidity and mortality among cancer patients. However, existing methods to assess skeletal muscle from CT are time-consuming, expensive, and require training. Clinic-friendly tools to screen for low skeletal muscle in cancer patients are urgently needed.

METHODS

We included 807 scans from non-metastatic colorectal cancer patients. With the digital ruler available in most radiological software, we implemented an abbreviated method to assess skeletal muscle area at the third lumbar vertebra (L3), which consisted of assessing the height and width of the psoas and paraspinal muscles and computing their combined 'linear area' in centimetres squared (cm2 ). A subset of CT scans was assessed twice by two analysts to compute intra-rater and inter-rater reliability. We derived cut-points for 'low' linear area using optimal stratification and then calculated the sensitivity and specificity of these cut-points relative to standard methods (total L3 cross-sectional area assessed with Slice-O-Matic research software). We further evaluated the association of low linear area with death from any cause after colorectal cancer diagnosis in Cox proportional hazards models adjusting for demographics, smoking, body mass index category, and tumour characteristics.

RESULTS

The linear area was highly correlated with total cross-sectional area assessed using standard methods [r = 0.92; 95% confidence interval (CI): 0.91, 0.93] overall and within subgroups defined by age, sex, and body mass index group. Intra-rater and inter-rater reliability were equally high (both intra-class correlations = 0.98). Cut-points for low linear area were sensitive (0.75; 95% CI: 0.70, 0.80) and specific (0.77; 95% CI: 0.73, 0.80) for identifying low skeletal muscle relative to the standard of total L3 cross-sectional area. The hazard ratio and 95% CI for death associated with a low linear area were hazard ratio = 1.66; 95% CI: 1.22, 2.25.

CONCLUSIONS

Clinic-friendly methods that assess linear area from CT scans are an accurate screening tool to identify low skeletal muscle among non-metastatic colorectal cancer patients. These linear measures are associated with mortality after colorectal cancer, suggesting they could be clinically useful both to improve prognostication and to provide a practical screening tool to identify cancer patients who require nutrition or exercise intervention.

One-year and three-year mortality prediction in adult major blunt trauma survivors: a National Retrospective Cohort Analysis

Background

Survivors of trauma are at increased risk of dying after discharge. Studies have found that age, head injury, injury severity, falls and co-morbidities predict long-term mortality. The objective of our study was to build a nomogram predictor of 1-year and 3-year mortality for major blunt trauma adult survivors of the index hospitalization.

Methods

Using data from the Singapore National Trauma Registry, 2011–2013, we analyzed adults aged 18 and over, admitted after blunt injury, with an injury severity score (ISS) of 12 or more, who survived the index hospitalization, linked to death registry data. The study population was randomly divided 60/40 into separate construction and validation datasets, with the model built in the construction dataset, then tested in the validation dataset. Multivariable logistic regression was used to analyze 1-year and 3-year mortality.

Results

Of the 3414 blunt trauma survivors, 247 (7.2%) died within 1 year, and 551 (16.1%) died within 3 years of injury. Age (OR 1.06, 95% CI 1.05–1.07, p < 0.001), male gender (OR 1.53, 95% CI 1.12–2.10, p < 0.01), low fall from 0.5 m or less (OR 3.48, 95% CI 2.06–5.87, p < 0.001), Charlson comorbidity index of 2 or more (OR 2.26, 95% CI 1.38–3.70, p < 0.01), diabetes (OR 1.31, 95% CI 1.68–2.52, p = 0.04), cancer (OR 1.76, 95% CI 0.94–3.32, p = 0.08), head and neck AIS 3 or more (OR 1.79, 95% CI 1.13–2.84, p = 0.01), length of hospitalization of 30 days or more (OR 1.99, 95% CI 1.02–3.86, p = 0.04) were predictors of 1-year mortality. This model had a c-statistic of 0.85. Similar factors were found significant for the model predictor of 3-year mortality, which had a c-statistic of 0.83. Both models were validated on the second dataset, with an overall accuracy of 0.94 and 0.84 for 1-year and 3-year mortality respectively.

Conclusions

Adult survivors of major blunt trauma can be risk-stratified at discharge for long-term support.