Core Domains for Research on Hospital Inactivity in Acutely Ill Older Adults: A Delphi Consensus Study.

OBJECTIVE: To identify core domains for research studies of physical activity and sedentary behavior during hospitalization for older adults with an acute medical illness. DESIGN: A 4-Round Delphi consensus process. Round 1 invited responses to open-ended questions to generate items for the core domains research. In rounds 2-4, participants were invited to use a Likert scale (1-9) to rate the importance of each core domain for research studies of physical activity and/or sedentary behavior in hospitalized older adults with an acute medical illness. SETTING: Online surveys. PARTICIPANTS: A total of 49 participants were invited to each round (international researchers, clinicians, policy makers and patients). Response rates across rounds 1-4 were 94%, 88%, 83% and 81%, respectively. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Consensus was defined a priori as ≥70% of respondents rating an item as "critical" (score≥7) and ≤15% of respondents rating an item as "not important" (score≤3). RESULTS: In round 2, a total of 9 of 25 core domains reached consensus agreement (physical functioning, general, role functioning, emotional functioning, global quality of life, hospital, psychiatric, cognitive functioning, carer burden). In round 3, an additional 8 reached consensus (adverse events, perceived health status, musculoskeletal, social functioning, vascular, cardiac, mortality, economic). Round 4 participants provided further review and a final rating of all 17 core domains that met consensus in previous rounds. Four core domains were rated as "critically important" to evaluate: physical functioning, social functioning, emotional functioning, and hospital outcomes. CONCLUSIONS: This preliminary work provides international and expert consensus-based core domains for development toward a core-outcome set for research, with the ultimate goal of fostering consistency in outcomes and reporting to accelerate research on effective strategies to address physical activity and/or sedentary behavior in older adults while hospitalized.

Evaluating Physical Functioning in Survivors of Critical Illness: Development of a New Continuum Measure for Acute Care.

OBJECTIVES: Evaluation of physical functioning is central to patient recovery from critical illness-it may enable the ability to determine recovery trajectories, evaluate rehabilitation efficacy, and predict individuals at highest risk of ongoing disability. The Physical Function in ICU Test-scored is one of four recommended physical functioning tools for use within the ICU; however, its utility outside the ICU is poorly understood. The De Morton Mobility Index is a common geriatric mobility tool, which has had limited evaluation in the ICU population. For the field to be able to track physical functioning recovery, we need a measurement tool that can be used in the ICU and post-ICU setting to accurately measure physical recovery. Therefore, this study sought to: 1) examine the clinimetric properties of two measures (Physical Function in ICU Test-scored and De Morton Mobility Index) and 2) transform these measures into a single measure for use across the acute care continuum. DESIGN: Clinimetric analysis. SETTING: Multicenter study across four hospitals in three countries (Australia, Singapore, and Brazil). PATIENTS: One hundred fifty-one ICU patients. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Physical function tests (Physical Function in ICU Test-scored and De Morton Mobility Index) were assessed at ICU awakening, ICU, and hospital discharge. A significant floor effect was observed for the De Morton Mobility Index at awakening (23%) and minimal ceiling effects across all time points (5-12%). Minimal floor effects were observed for the Physical Function in ICU Test-scored across all time points (1-7%) and a significant ceiling effect for Physical Function in ICU Test-scored at hospital discharge (27%). Both measures had strong concurrent validity, responsiveness, and were predictive of home discharge. A new measure was developed using Rasch analytical principles, which involves 10 items (scored out of 19) with minimal floor/ceiling effects. CONCLUSIONS: Limitations exist for Physical Function in ICU Test-scored and De Morton Mobility Index when used in isolation. A new single measure was developed for use across the acute care continuum.

A scoping review of interventions using accelerometers to measure physical activity or sedentary behaviour during hospitalization.

OBJECTIVE: To identify interventions using wearable accelerometers to measure physical activity and/or sedentary behaviour in adults during hospitalization for an acute medical/surgical condition. DATA SOURCES: Four databases were searched in August 2019 (MEDLINE, CINAHL, Scopus, EMBASE). REVIEW METHODS: Studies were selected if they described an intervention in adults with a medical/surgical condition, and concurrently reported an accelerometer-derived measure of physical activity and/or sedentary behaviour while participants were admitted. Items were screened for eligibility in duplicate. Included studies were synthesized to describe intervention types, feasibility and potential effectiveness. RESULTS: Twenty-two studies were included, reporting on 3357 participants (2040 with accelerometer data). Identified types of interventions were: pre-habilitation (n = 2) exercise (n = 3), patient behaviour change with self-monitoring (n = 6), models of care (n = 5), implementing system change (n = 2), surgical technique (n = 2) patients wearing day clothes (n = 1) and education about activity in hospital (n = 1). Of 16 studies that reported intervention effects on physical activity, 11 reported a favourable impact including studies of: pre-habilitation, self-monitoring (accelerometry or an activity whiteboard), physiotherapy, an early mobility bundle, minimally invasive surgery, an education booklet and by implementing system change. Of the six studies that reported intervention effects on sedentary behaviour, there was a favourable impact with an activity whiteboard, models of care and an education booklet. CONCLUSION: Accelerometer-derived measures of physical activity and/or sedentary behaviour have been used to describe sample characteristics and intervention effects in studies of hospitalized adults. Interventions may involve a range of health professionals, but less is known about sedentary behaviour in this setting.

Recommendations for older adults' physical activity and sedentary behaviour during hospitalisation for an acute medical illness: an international Delphi study.

BACKGROUND: Immobility is major contributor to poor outcomes for older people during hospitalisation with an acute medical illness. Yet currently there is no specific mobility guidance for this population, to facilitate sustainable changes in practice. This study aimed to generate draft physical activity (PA) and sedentary behaviour (SB) recommendations for older adults' during hospitalisation for an acute medical illness. METHODS: A 4-Round online Delphi consensus survey was conducted. International researchers, medical/nursing/physiotherapy clinicians, academics from national PA/SB guideline development teams, and patients were invited to participate. Round 1 sought responses to open-ended questions. In Rounds 2-3, participants rated the importance of items using a Likert scale (1-9); consensus was defined a priori as: ≥70% of respondents rating an item as "critical" (score ≥ 7) and ≤ 15% of respondents rating an item as "not important" (score ≤ 3). Round 4 invited participants to comment on draft statements derived from responses to Rounds 1-3; Round 4 responses subsequently informed final drafting of recommendations. RESULTS: Forty-nine people from nine countries were invited to each Round; response rates were 94, 90, 85 and 81% from Rounds 1-4 respectively. 43 concepts (items) from Rounds 2 and 3 were incorporated into 29 statements under themes of PA, SB, people and organisational factors in Round 4. Examples of the final draft recommendations (being the revised version of statements with highest participant endorsement under each theme) were: "some PA is better than none", "older adults should aim to minimise long periods of uninterrupted SB during waking hours while hospitalised", "when encouraging PA and minimising SB, people should be culturally responsive and mindful of older adults' physical and mental capabilities" and "opportunities for PA and minimising SB should be incorporated into the daily care of older adults with a focus on function, independence and activities of daily living". CONCLUSIONS: These world-first consensus-based statements from expert and stakeholder consultation provide the starting point for recommendations to address PA and SB for older adults hospitalised with an acute medical illness. Further consultation and evidence review will enable validation of these draft recommendations with examples to improve their specificity and translation to clinical practice.

The sedentary behaviour and physical activity patterns of survivors of a critical illness over their acute hospitalisation: An observational study.

BACKGROUND: Physical function is often poor in intensive care unit (ICU) survivors, yet objective descriptions of sedentary behaviour and physical activity during acute hospitalisation are lacking. OBJECTIVE: The objective of this study was to examine sedentary and activity patterns during patients' hospital-based recovery from a critical illness and associations with physical function, muscle strength, and length of stay (LOS). METHODS: This was a prospective cohort study in a tertiary ICU and acute hospital wards, which recruited 40 adults who required ≥5 days of mechanical ventilation. Data were collected at awakening (T1), ICU discharge (T2), and hospital discharge (T3), which included monitoring of body posture (sedentary behaviour) using the activPAL and activity intensity using the GENEActiv. Data were reported as time spent lying/sitting and upright, with the number of sit-to-stand transitions and upright bouts. Statistical analysis was conducted using repeated-measures analysis of variance and Spearman's rho. RESULTS: From awakening to hospital discharge (T1-T3, n = 23), there was a mean [95% confidence interval] decrease in % time spent lying/sitting (-3.0% [-4.6% to1.4%], p ≤ 0.001) corresponding to increased time spent upright (43.0 min [19.9, 66.1], p ≤ 0.001). Sit-to-stand transitions increased (18 [11, 28], p ≤ 0.001). The number of upright bouts ≥2 and ≥ 5 min increased (both p ≤ 0.001), but only from ICU to hospital discharge (T2-T3, 5.3 [3.1, 7.6] and 2.3 [0.9, 3.8] respectively). At ICU discharge (T2), less % of time spent lying/sitting, more minutes spent upright, and more transitions were associated with better physical function (Physical Function in Intensive Care Test-scored and de Morton Mobility Index; all rho ≥+/-0.730, p ≤ 0.001) and muscle strength (hand grip, Medical Research Council sum-score; all rho≥+/-0.505, p ≤ 0.001). There were no associations between accelerometry and hospital LOS. CONCLUSIONS: ICU survivors' transition from highly sedentary behaviour to low intensity activity over their acute hospitalisation. Sedentary breaks may be not spread over the day such that modifying sedentary behaviour to break up prolonged lying/sitting may be a focus for future research. CLINICAL TRIAL REGISTRATION: NCT02881801.

Early Detection of Muscle Weakness and Functional Limitations in the Critically Ill: A Retrospective Evaluation of Bioimpedance Spectroscopy.

BACKGROUND: The potential for bioimpedance spectroscopy (BIS) to identify muscle weakness and functional limitations in critical illness is unknown; this study aimed to determine association of BIS with strength/function and differences between 3 intensive care units (ICUs). METHODS: A retrospective post hoc analysis of BIS, strength, and functional data from adults who required ≥48 hours of mechanical ventilation was conducted. Measures of body composition included the proportion (%) of total body water (TBW), fat mass (FM), and fat-free mass (FFM). The Medical Research Council sum score (MRC-ss) and Physical Function in ICU Test-Scored (PFIT-s) were used for strength and functional assessments. Nonparametric cross-sectional analyses were done at enrollment (≤48 hours of admission: site-A, site-C) and awakening from sedation (site-A, site-B). Raw impedance variables including 50-kHz phase angle (PA) and impedance ratio (IR) were available from site-A and site-B. RESULTS: Participants were 135 adults (site-A n=59, site-B n=33, site-C n=44), with a median (interquartile range) age of 59 (50-69) years. At enrollment, TBW%, FM%, and FFM% were similar between site-A and site-C (P>.05); pooled data were not associated with MRC-ss at awakening or MRC-ss/PFIT-s at ICU discharge. At awakening, there was less TBW%, less FFM%, and greater FM% at site-B vs site-A (P≤.001) but no associations with MRC-ss/PFIT-s when using pooled data. Trends with pooled data of a lower PA and higher IR being associated with awakening MRC-ss were confirmed within site-B (PA ρ=0.70, P≤.001; IR ρ=-0.79, P≤.001). CONCLUSION: Site-by-site data suggest that raw impedance variables might be useful for screening weakness and poor function.

Physical Activity of ICU Survivors during Acute Admission: Agreement of the activPAL with Observation.

Purpose: We estimated the agreement of a thigh-worn accelerometer, the activPAL, used to measure activity and sedentary parameters, with observed mobility assessments of intensive care unit (ICU) survivors. Method: We prospectively compared activPAL measurements with direct observation during assessments at discharge from the ICU or acute hospital in eight participants with a median age of 56 (1st-3rd quartile 48-65) years and an Acute Physiology and Chronic Health Evaluation II score of 23 (1st-3rd quartile 17-24). Frequency of sit-to-stand transitions; time spent standing, stepping, upright (standing and stepping), and sedentary (lying/sitting); and total steps were described; analysis was performed using Bland-Altman plots and calculating the absolute percent error. Results: All sit-to-stand transitions were accurately detected. The mean difference on the Bland-Altman plots suggested an overestimation of standing time with the activPAL of 31 (95% CI: -9, 71) seconds and underestimation of stepping time by 25 (95% CI: -47, -3) seconds. The largest median absolute percent errors were for standing time (21.9%) and stepping time (18.7%); time spent upright (1.7%) or sedentary (0.3%) was more accurately estimated. The activPAL underestimated total steps per session, achieving the largest percent error (70.8%). Conclusion: Because it underestimated step count, the activPAL likely incorrectly recorded stepping time as standing time, so that time spent upright was the measure of activity with the smallest error. Sedentary behaviour, including frequency of transitions, was validly assessed.

Objectif : évaluer l'efficacité d'un accéléromètre porté sur la cuisse, l'activPAL, pour mesurer les paramètres d'activité et de comportement sédentaire par l'évaluation de la mobilité observée chez des survivants d'une unité de soins intensifs (USI). Méthodologie : les chercheurs ont procédé à la comparaison prospective du moniteur activPAL pour orienter l'observation de huit participants ayant un âge médian de 56 ans (premier au troisième quartile de 48 à 65 ans) et un score APACHE II de 23 (premier au troisième quartile de 17 à 24 ans) au moment des évaluations au congé de l'USI ou d'un hôpital de soins aigus. Ils ont décrit la fréquence des transitions assis-debout, le temps passé en position debout, les pas, la position verticale (position debout et pas) et les comportements sédentaires (couché, assis), de même que le total des pas. Ils ont effectué une analyse à l'aide du graphique de Bland-Altman et calculé l'erreur absolue en pourcentage. Résultats : toutes les transitions assis-debout ont été décelées correctement. La différence moyenne (IC à 95%) sur le graphique de Bland-Altman laissait croire à une surestimation de 31 secondes (IC à 95 % : −9 à 71) du temps passé en position debout selon le moniteur activPAL et à une sous-estimation de 25 secondes (IC à 95 % : −47 à −3) du temps passé à faire des pas. Le pourcentage d'erreur absolue médian le plus important touchait le temps passé en position debout (21,9 %) et le temps passé à faire des pas (18,7 %). L'évaluation du temps passé en position verticale (1,7 %) ou du comportement sédentaire (0,3 %) était plus précis. Le moniteur activPAL sous-estimait le nombre total de pas par séance, ce qui correspondait au plus grand pourcentage d'erreur (70,8 %). Conclusion : puisqu'il sous-estimait le nombre de pas, il est fort probable que le moniteur activPAL enregistrait à tort le temps passé à faire des pas comme s'il s'agissait de temps en position debout, de manière que la période passée en position verticale était la mesure d'activité comportant le plus petit taux d'erreur. L'évaluation du comportement sédentaire, y compris la fréquence des transitions, était valide.

Tracheostomy Tube Type and Inner Cannula Selection Impact Pressure and Resistance to Air Flow.

BACKGROUND: Advancements in tracheostomy tube design now provide clinicians with a range of options to facilitate communication for individuals receiving ventilator assistance through a cuffed tube. Little is known about the impact of these modern design features on resistance to air flow. METHODS: We undertook a bench model test to measure pressure-flow characteristics and resistance of a range of tubes of similar outer diameter, including those enabling subglottic suction and speech. A constant inspiratory ± expiratory air flow was generated at increasing flows up to 150 L/min through each tube (with or without optional, mandatory, or interchangeable inner cannula). Driving pressures were measured, and resistance was calculated (cm H2O/L/s). RESULTS: Pressures changed with increasing flow (P < .001) and tube type (P < .001), with differing patterns of pressure change according to the type of tube (P < .001) and direction of air flow. The single-lumen reference tube encountered the lowest inspiratory and expiratory pressures compared with all double-lumen tubes (P < .001); placement of an optional inner cannula increased bidirectional tube resistance by a factor of 3. For a tube with interchangeable inner cannulas, the type of cannula altered pressure and resistance differently (P < .001); the speech cannula in particular amplified pressure-flow changes and increased tube resistance by more than a factor of 4. CONCLUSIONS: Tracheostomy tube type and inner cannula selection imposed differing pressures and resistance to air flow during inspiration and expiration. These differences may be important when selecting airway equipment or when setting parameters for monitoring, particularly for patients receiving supported ventilation or during the weaning process.

Myopathic characteristics in septic mechanically ventilated patients.

PURPOSE OF REVIEW: Survivors of a critical illness may experience poor physical function and quality of life as a result of reduced skeletal muscle mass and strength during their acute illness. Patients diagnosed with sepsis are particularly at risk, and mechanical ventilation may result in diaphragm dysfunction. Interest in the interaction of these conditions is both growing and important to understand for individualized patient care. RECENT FINDINGS: This review describes developments in the presentation of both diaphragm and limb myopathy in critical illness, as measured from muscle biopsy and at the bedside with various imaging and strength-testing modalities. The influence of unloading of the diaphragm with mechanical ventilation and peripheral muscles with immobilization in septic patients has been recently questioned. Systemic inflammation appears to primarily accelerate and accentuate dysfunction, which may be remedied by early mobilization and augmented with developing muscle and/or nerve stimulation techniques. SUMMARY: Many acute muscle changes in septic patients are likely to stem from pre-existing impairments, which should provide context for clinical evaluations of strength. During illness, sarcolemmal injury promotes a cascade of intra-cellular abnormalities. As unique characteristics of ICU-acquired weakness and differential effects on muscle groups are understood, early diagnosis and management should be facilitated.

Expert consensus and recommendations on safety criteria for active mobilization of mechanically ventilated critically ill adults.

INTRODUCTION: The aim of this study was to develop consensus recommendations on safety parameters for mobilizing adult, mechanically ventilated, intensive care unit (ICU) patients. METHODS: A systematic literature review was followed by a meeting of 23 multidisciplinary ICU experts to seek consensus regarding the safe mobilization of mechanically ventilated patients. RESULTS: Safety considerations were summarized in four categories: respiratory, cardiovascular, neurological and other. Consensus was achieved on all criteria for safe mobilization, with the exception being levels of vasoactive agents. Intubation via an endotracheal tube was not a contraindication to early mobilization and a fraction of inspired oxygen less than 0.6 with a percutaneous oxygen saturation more than 90% and a respiratory rate less than 30 breaths/minute were considered safe criteria for in- and out-of-bed mobilization if there were no other contraindications. At an international meeting, 94 multidisciplinary ICU clinicians concurred with the proposed recommendations. CONCLUSION: Consensus recommendations regarding safety criteria for mobilization of adult, mechanically ventilated patients in the ICU have the potential to guide ICU rehabilitation whilst minimizing the risk of adverse events.

Alterations in respiratory and limb muscle strength and size in patients with sepsis who are mechanically ventilated.

BACKGROUND: Skeletal muscle wasting and weakness are common in patients with sepsis in the intensive care unit, although less is known about deficits in diaphragm and limb muscles when mechanical ventilation also is required. OBJECTIVE: The objective of this study was to concurrently investigate relative differences in both thickness and strength of respiratory and peripheral muscles during routine care. DESIGN: A prospective, cross-sectional study of 16 alert patients with sepsis and 16 people who were healthy (control group) was used. METHODS: Assessment was made of the diaphragm, upper arm, forearm, and thigh muscle thicknesses with the use of ultrasound; respiratory muscle strength by means of maximal inspiratory pressure; and isometric handgrip, elbow flexion, and knee extension forces with the use of portable dynamometry. To describe relative changes, data also were normalized to fat-free body mass (FFM) measured by bioelectrical impedance spectroscopy. RESULTS: Patients (9 men, 7 women; mean age=62 years, SD=17) were assessed after a median of 16 days (interquartile range=11-29) of intensive care unit admission. Patients' diaphragm thickness did not differ from that of the control group, even for a given FFM. When normalized to FFM, only the difference in patients' mid-thigh muscle size significantly deviated from that of the control group. Within the patient sample, all peripheral muscle groups were thinner compared with the diaphragm. Patients were significantly weaker than were the control group participants in all muscle groups, including for a given FFM. Within the critically ill group, limb weakness was greater than the already-significant respiratory muscle weakness. LIMITATIONS: Volitional strength tests were applied such that successive measurements from earlier in the course of illness could not be reliably obtained. CONCLUSIONS: When measured at bedside, survivors of sepsis and a period of mechanical ventilation may have respiratory muscle weakness without remarkable diaphragm wasting. Furthermore, deficits in peripheral muscle strength and size may exceed those in the diaphragm.

Fluid balance does not predict estimated sodium balance in critically ill mechanically ventilated patients.

BACKGROUND: Distribution of total body water (TBW) depends on local and systemic factors including osmolality, relative sodium content and permeability. Although positive fluid balance has been associated with increased morbidity and mortality in critically ill patients, the mechanisms and relative roles of sodium balance and water distribution are uncertain. OBJECTIVE: To track changes in sodium and fluid balance, respiratory function and body composition in patients who required mechanical ventilation for ≥48 hours. DESIGN, SETTING AND PARTICIPANTS: Prospective observational study, set in a tertiary intensive care unit, of 10 patients (seven men) with a mean age of 60 years (standard deviation [SD],12 years) and mean admission Acute Physiology and Chronic Health Evaluation (APACHE) III score of 71 (SD, 26). METHODS: Sodium and fluid balances were estimated daily for up to 5 days, following institution of mechanical ventilation on Day 0. Serum sodium level, oxygenation (PaO(2)/FIO(2)), body weight, intracellular and extracellular fluid (ECF) distribution (bioelectrical impedance spectroscopy), and blinded chest x-ray oedema scores were performed daily. RESULTS: After 5 days of mechanical ventilation, the cumulative fluid balance was - 954 mL (SD, 3181 mL) and estimated cumulative sodium balance was 253 mmol (SD, 346 mmol). Serum sodium had increased from 140 mmol/L (SD, 4 mmol/L) to 147 mmol/L (SD, 5 mmol/L). Cumulative sodium balance was weakly correlated with worsening chest x-ray score (r = 0.35, P = 0.004), a reduction in PaO(2)/ FIO(2) ratio (r = - 0.52, P = 0.001) and 24-hour urinary sodium (r = - 0.24, P = 0.02). Between Days 1 and 5, body weight decreased (- 2.7 kg; SD, 1.4 kg) and TBW decreased (- 3.4 L; SD, 1.3 L), despite a rise in ECF distribution (1.4% of TBW; SD, 1.9% of TBW). CONCLUSIONS: Fluid balance may not reflect sodium balance in critically ill patients. As sodium balance correlates with respiratory dysfunction and increased extracellular volume, further studies examining sodium balance and morbidity seem warranted.

Muscle strength assessment in critically ill patients with handheld dynamometry: an investigation of reliability, minimal detectable change, and time to peak force generation.

PURPOSE: Dynamometry is an objective tool for volitional strength evaluation that may overcome the limited sensitivity of the Medical Research Council scale for manual muscle tests, particularly at grades 4 and 5. The primary aims of this study were to investigate the reliability, minimal detectable change, and time to peak muscle force, measured with portable dynamometry, in critically ill patients. MATERIALS AND METHODS: Isometric hand grip, elbow flexion, and knee extension were measured with portable dynamometry. RESULTS: Interrater consistency (intraclass correlation coefficient [95% confidence interval]) (0.782 [0.321-0.930] to 0.946 [0.840-0.982]) and test-retest agreement (0.819 [0.390-0.943] to 0.918 [0.779-0.970]) were acceptable for all dynamometry forces, with the exception of left elbow flexion. Despite generally good reliability, a mean change (upper 95% confidence interval) of 2.8 (7.8) kg, 1.9 (5.2) kg, and 2.6 (7.1) kg may be required from a patient's baseline force measurement of right grip, elbow flexion, and knee extension to reflect real force changes. There was also a delay in the time for critically ill patients to generate peak muscle forces, compared with healthy controls (P ≤ .001). CONCLUSIONS: Dynamometry can provide reliable measurements in alert critically ill patients, but moderate changes in strength may be required to overcome measurement error, during the acute recovery period. Deficits in force timing may reflect impaired neuromuscular control.

Body composition analysis in critically ill survivors: a comparison of bioelectrical impedance spectroscopy devices.

BACKGROUND: Body composition is commonly altered in response to critical illness and can be estimated at the bedside with bioelectrical impedance spectroscopy (BIS). Different electrode configurations may be used to mitigate assumptions of the technique, but the reliability of tetra-polar and octo-polar arrangements has yet to be established. This study aimed to compare both configurations, in a prospective observational study of 17 critically ill survivors and 12 healthy controls. METHODS: Weight, supine body length, and BIS on both tetra-polar and octo-polar configured devices were recorded, then repeated 2 days later. Bioelectrical impedance vector analysis was subsequently performed using data from the tetra-polar device at a frequency of 50 kHz. RESULTS: Test-retest agreement was acceptable for the tetra-polar device (intraclass correlation coefficient range, patients: 0.876-0.988 vs controls: 0.983-0.998, P ≤ 0.001). However, lower and wider ranging test-retest intraclass correlation coefficients were obtained with the octo-polar instrument in both groups. Furthermore, there was a difference in the mass/volume of body compartments measured on each device in both patients (P ≤ .017) and controls (P ≤ .045). A change in the composition profile of critically ill males was evident between measurement occasions, which was reflected by a reduction in body weight of 1.6 (1.5) kg (P ≤ 0.001) across the sample over the same period. CONCLUSIONS: BIS devices should not be used interchangeably in the clinical setting. The reliability of the tetra-polar instrument was good, but daily fluctuations in body weight may have affected the results.

Diaphragm and peripheral muscle thickness on ultrasound: intra-rater reliability and variability of a methodology using non-standard recumbent positions.

BACKGROUND AND OBJECTIVE: Reliable measurement of diaphragm and peripheral muscle thickness, using diagnostic ultrasound, has only been validated in the erect posture. However, in many clinical populations, including critically ill patients, the erect posture presents logistic difficulties. This study aimed to validate ultrasound measurement of diaphragm and peripheral muscle thickness in the recumbent position. METHODS: An observational methodology of repeated but blind ultrasound and anthropometric measurements was applied, to assess inta-rater reliability. Thirteen healthy volunteers (aged 20-73years) participated. A pneumotachograph was used to target lung volume, as diaphragm thickness was measured from ultrasound at end-expiration, and both 25% and 50% of inspiratory capacity, while semi-recumbent. The thicknesses of the mid-upper arm, mid-forearm and mid-thigh musculature were also measured bilaterally while supine. RESULTS: Diaphragm thickness could be reliably measured at end-expiration (intra-class correlation coefficient (ICC)=0.990, 95% confidence interval: 0.918-0.998), 25% of inspiratory capacity (ICC=0.959 (0.870-0.988)) and 50% of inspiratory capacity (ICC=0.994 (0.980-0.998)). Peripheral muscle thickness measurements were also reliable (ICC=0.998-1.0). Supine anthropometric measurements of limb segment lengths and girths were highly reproducible. CONCLUSIONS: This ultrasound technique has good reliability in recumbent positions, making it useful for application to clinical populations when the erect posture is not practical.