Energy expenditure in acute posttraumatic amputation: comparison of four methods for assessment

Gait Alteration in Individual with Limb Loss: The Role of Inertial Sensors

Amputation has a big impact on the functioning of patients, with negative effects on locomotion and dexterity. In this context, inertial measurement units represent a useful tool in clinical practice for motion analysis, and in the development of personalized aids to improve a patient's function. To date, there is still a gap of knowledge in the scientific literature on the application of inertial sensors in amputee patients. Thus, the aim of this narrative review was to collect the current knowledge on this topic and stimulate the publication of further research. Pubmed, Embase, Scopus, and Cochrane Library publications were screened until November 2022 to identify eligible studies. Out of 444 results, we selected 26 articles focused on movement analysis, risk of falls, energy expenditure, and the development of sensor-integrated prostheses. The results showed that the use of inertial sensors has the potential to improve the quality of life of patients with prostheses, increasing patient safety through the detection of gait alteration; enhancing the socio-occupational reintegration through the development of highly technologic and personalized prosthesis; and by monitoring the patients during daily life to plan a tailored rehabilitation program.

The influence of traumatic transfemoral amputation on metabolic cost across walking speeds

BACKGROUND

Recent literature indicates equivalent costs of walking can be achieved after a transtibial amputation when the individual is young, active, and/or has extensive access to rehabilitative care. It is unknown if a similar cohort with transfemoral amputation can also achieve lower metabolic costs of walking than previously reported.

OBJECTIVE

Compare metabolic cost in individuals with a transfemoral amputation to controls and to the literature across a range of walking speeds.

STUDY DESIGN

Cross-sectional.

METHODS

A total of 14 individuals with a unilateral transfemoral amputation (27 ± 5 years, N = 4 mechanical knee, N = 10 microprocessor knee) and 14 able-bodied controls (26 ± 6 years) walked at self-selected and four standardized speeds. Heart rate, metabolic rate (mL O₂/kg/min), metabolic cost (mL O₂/kg/m), and rating of perceived exertion were calculated.

RESULTS

Self-selected speed was 8.6% slower in the transfemoral amputation group ( p = 0.031). Across standardized speeds, both metabolic rate and metabolic cost ranged from 44%-47% greater in the transfemoral amputation group ( p < 0.001), heart rate was 24%-33% greater ( p < 0.001), and perceived exertion was 24%-35% greater ( p < 0.009).

CONCLUSION

Although the transfemoral amputation group was relatively young, physically fit, and had extensive access to rehabilitative care, the metabolic cost of walking fell within the ranges of the literature on older or presumably less fit individuals with transfemoral amputation. Clinical relevance Developments in prosthetic technology and/or rehabilitative care may be warranted and may reduce the metabolic cost of walking in individuals with a transfemoral amputation.

Indirect calorimetry using a ventilated hood may be easier than using a facemask to achieve steady state when measuring resting energy expenditure

Previous studies have demonstrated differences in subjective comfort between different gas collecting methods during resting energy expenditure (REE) measurement. We hypothesized that gas collecting methods may have an influence on the time to achieve steady state and the optimum abbreviated period to estimate REE. Gas exchange variables were obtained using IIM-IC-100 (ventilated hood) and VO2000 (facemask) alternately among 32 healthy adults. A 10-minute test period was divided into 5-minute sliding time windows to obtain a subtle profile process of the coefficient of variation (CV) and REE. Friedman's test was used to compare the CVs during the test process. To compare the REE between abbreviated measurements and the reference, paired t test, linear regression, and Bland-Altman test were used. There were no significant differences between the CVs in each adjacent group of 5-minute intervals for IIM-IC-100 (P = .896). CV1 and CV2 were significantly higher than CV3-CV6 for VO2000 (P = .001). The proportion of subjects achieving steady state was lower with VO2000 (59.4-81.3%) than with IIM-IC-100 (84.4-91.8%). REE of the 2nd and 3rd 5-minute intervals did not differ from the reference, and they explained 94.7% (P < .001) and 94.9% (P < .001) of the last 5-minute REE variance, with the 95% limits of agreement ranging from -100.0 to 139.2 kcal/d and -139.5 to 182.5 kcal/d for IIM-IC-100 and VO2000, respectively. In conclusion, using a ventilated hood may be easier than using a facemask to achieve steady state and reduce the time required to estimate REE.

Energy and Protein in Critically Ill Patients with AKI: A Prospective, Multicenter Observational Study Using Indirect Calorimetry and Protein Catabolic Rate

The optimal nutritional support in Acute Kidney Injury (AKI) still remains an open issue. The present study was aimed at evaluating the validity of conventional predictive formulas for the calculation of both energy expenditure and protein needs in critically ill patients with AKI. A prospective, multicenter, observational study was conducted on adult patients hospitalized with AKI in three different intensive care units (ICU). Nutrient needs were estimated by different methods: the Guidelines of the European Society of Parenteral and Enteral Nutrition (ESPEN) for both calories and proteins, the Harris-Benedict equation, the Penn-State and Faisy-Fagon equations for energy. Actual energy and protein needs were repeatedly measured by indirect calorimetry (IC) and protein catabolic rate (PCR) until oral nutrition start, hospital discharge or renal function recovery. Forty-two patients with AKI were enrolled, with 130 IC and 123 PCR measurements obtained over 654 days of artificial nutrition. No predictive formula was precise enough, and Bland-Altman plots wide limits of agreement for all equations highlight the potential to under- or overfeed individual patients. Conventional predictive formulas may frequently lead to incorrect energy and protein need estimation. In critically ill patients with AKI an increased risk for under- or overfeeding is likely when nutrient needs are estimated instead of measured.

Can real-time visual feedback during gait retraining reduce metabolic demand for individuals with transtibial amputation?

The metabolic demand of walking generally increases following lower extremity amputation. This study used real-time visual feedback to modify biomechanical factors linked to an elevated metabolic demand of walking in individuals with transtibial amputation. Eight persons with unilateral, traumatic transtibial amputation and 8 uninjured controls participated. Two separate bouts of real-time visual feedback were provided during a single session of gait retraining to reduce 1) center of mass sway and 2) thigh muscle activation magnitudes and duration. Baseline and post-intervention data were collected. Metabolic rate, heart rate, frontal plane center of mass sway, quadriceps and hamstrings muscle activity, and co-contraction indices were evaluated during steady state walking at a standardized speed. Visual feedback successfully decreased center of mass sway 12% (p = 0.006) and quadriceps activity 12% (p = 0.041); however, thigh muscle co-contraction indices were unchanged. Neither condition significantly affected metabolic rate during walking and heart rate increased with center-of-mass feedback. Metabolic rate, center of mass sway, and integrated quadriceps muscle activity were all not significantly different from controls. Attempts to modify gait to decrease metabolic demand may actually adversely increase the physiological effort of walking in individuals with lower extremity amputation who are young, active and approximate metabolic rates of able-bodied adults.

Assessing resting energy expenditure in overweight and obese adolescents in a clinical setting: validity of a handheld indirect calorimeter

BACKGROUND

Accurately determining energy requirements is key for nutritional management of pediatric obesity. Recently, a portable handheld indirect calorimeter, MedGem (MG) has become available to measure resting energy expenditure (REE). Our work aims to determine the clinical validity and usefulness of MG to measure REE in overweight and obese adolescents.

METHODS

Thirty-nine overweight and obese adolescents (16 male (M): 23 female (F), 15.2 ± 1.9 y, BMI percentile: 98.6 ± 2.2%) and 15 normal weight adolescents (7M: 8F, age 15.2 ± 2.0 y, BMI percentile: 39.2 ± 20.9%) participated. REE was measured with both MG and standard indirect calorimeter (VMax) in random order.

RESULTS

MG REE (1,600 ± 372 kcal/d) was lower than VMax REE (1,727 ± 327 kcal/) in the overweight and obese adolescents. Bland Altman analysis (MG -VMax) showed a mean bias of -127 kcal/d (95% CI = -72 to -182 kcal/d, P < 0.001), and a proportional bias existed such that lower measured REE by VMax was underestimated by MG, and higher measured REE by VMax were overestimated by MG.

CONCLUSION

MG systematically underestimates REE in the overweight and adolescent population, thus the MG portable indirect calorimeter is not recommended for routine use. Considering that it is a systematic underestimation of REE, MG may be clinically acceptable, only if used with caution.

Provision of nutrition support therapies in the recent Iraq and Afghanistan conflicts

This article describes the experience of nutrition support practitioners, specifically dietitians, providing care to combat casualties. It provides a brief overview of dietitians' induction into armed service but focuses primarily on their role in providing nutrition support during the most recent conflicts in Iraq and Afghanistan. The current system of combat casualty care is discussed with specific emphasis on providing early and adequate nutrition support to U.S. combat casualties from injury, care in theater combat support hospitals (CSHs)/expeditionary medical support (EMEDs), and en route care during critical care air transport (CCAT) up to arrival at treatment facilities in the United States. The article also examines practices and challenges faced in the CSHs/EMEDs providing nutrition support to non-U.S. or coalition patients. Over the past decade in armed conflicts, dietitians, physicians, nurses, and other medical professionals have risen to challenges, have implemented systems, and continue working to optimize treatment across the spectrum of combat casualty care.