Association of Mechanical Energy and Power with Postoperative Pulmonary Complications in Lung Resection Surgery: A Post Hoc Analysis of Randomized Clinical Trial Data.

BACKGROUND: Mechanical power (MP), the rate of mechanical energy (ME) delivery, is a recently introduced unifying ventilator parameter consisting of tidal volume, airway pressures, and respiratory rates, which predicts pulmonary complications in several clinical contexts. However, ME has not been previously studied in the perioperative context, and neither parameter has been studied in the context of thoracic surgery utilizing one-lung ventilation. METHODS: The relationships between ME variables and postoperative pulmonary complications were evaluated in this post hoc analysis of data from a multicenter randomized clinical trial of lung resection surgery conducted between 2020 and 2021 (n = 1,170). Time-weighted average MP and ME (the area under the MP time curve) were obtained for individual patients. The primary analysis was the association of time-weighted average MP and ME with pulmonary complications within 7 postoperative days. Multivariable logistic regression was performed to examine the relationships between energy variables and the primary outcome. RESULTS: In 1,055 patients analyzed, pulmonary complications occurred in 41% (431 of 1,055). The median (interquartile ranges) ME and time-weighted average MP in patients who developed postoperative pulmonary complications versus those who did not were 1,146 (811 to 1,530) J versus 924 (730 to 1,240) J (P < 0.001), and 6.9 (5.5 to 8.7) J/min versus 6.7 (5.2 to 8.5) J/min (P = 0.091), respectively. ME was independently associated with postoperative pulmonary complications (ORadjusted, 1.44 [95% CI, 1.16 to 1.80]; P = 0.001). However, the association between time-weighted average MP and postoperative pulmonary complications was time-dependent, and time-weighted average MP was significantly associated with postoperative pulmonary complications in cases utilizing longer periods of mechanical ventilation (210 min or greater; ORadjusted, 1.46 [95% CI, 1.11 to 1.93]; P = 0.007). Normalization of ME and time-weighted average MP either to predicted body weight or to respiratory system compliance did not alter these associations. CONCLUSIONS: ME and, in cases requiring longer periods of mechanical ventilation, MP were independently associated with postoperative pulmonary complications in thoracic surgery.

Practice and proficiency: Factors that facilitate infant walking skill.

Infant walking skill improves with practice-crudely estimated by elapsed time since walk onset. However, despite the robust relation between elapsed time (months walking) and skill, practice is likely constrained and facilitated by infants' home environments, sociodemographic influences, and spontaneous activity. Individual pathways are tremendously diverse in the timing of walk onset and the trajectory of improvement, and presumably, in the amount and type of practice. So, what factors affect the development of walking skill? We examined the role of months walking, walk onset age, spontaneous locomotor activity, body dimensions, and environmental factors on the development of walking skill in two sociodemographically distinct samples (ns = 38 and 44) of 13-, 15-, and 19-month-old infants. Months walking best predicted how well infants walked, but environmental factors and spontaneous activity explained additional variance in walking skill. Specifically, less crowded homes, a larger percentage of time in spontaneous walking, and a smaller percentage of short walking bouts predicted more mature walking. Walk onset age differed by sample but did not affect walking skill. Findings indicate that elapsed time since walk onset remains a robust predictor of walking skill, but environmental factors and spontaneous activity also contribute to infants' practice, thereby affecting walking skill.

Early Treadmill Practice in Infants Born With Myelomeningocele: A Pilot Study.

PURPOSE: To determine the feasibility of an early treadmill training program for infants with myelomeningocele (MMC) and to measure changes in overt infant motor development and control, including mechanisms underlying the overt changes. METHODS: Ten infants with MMC were initially enrolled: 8 infants completed 12 consecutive months of training, and 2 completed 6 months of training. Training consisted primarily of home-based, parent-administered treadmill stepping practice 5 days per week, 10 minutes per day starting within 6 months postbirth. We measured motor milestones, treadmill steps, spinal-level reflexes, and body composition. RESULTS: Infants showed earlier acquisition of gross motor skills than previously reported. The number of alternating steps performed increased, indicating more complex neuromotor control and strength. Integrity of monosynaptic pathways and body composition were improved after controlling for chronological age. CONCLUSIONS: This study demonstrates the feasibility of using early, home-based treadmill training for infants with MMC starting within 6 months postbirth.

The cost of simplifying complex developmental phenomena: a new perspective on learning to walk.

Researchers can study complex developmental phenomena with all the inherent noise and complexity or simplify behaviors to hone in on the essential aspects of a phenomenon. We used the development of walking as a model system to compare the costs and benefits of simplifying a complex, noisy behavior. Traditionally, researchers simplify infant walking by recording gait measures as infants take continuous, forward steps along straight paths. Here, we compared the traditional straight-path task with spontaneous walking during 20 minutes of free play in 97 infants (10.75-19.99 months of age). We recorded infants' footfalls on an instrumented floor to calculate gait measures in the straight-path and free-play tasks. In addition, we scored videos for other critical aspects of spontaneous walking-steps per bout, shape of walking path, and step direction. Studying infant walking during free play incurred no cost compared with the straight-path task, but considerable benefits. Straight-path gait was highly correlated with spontaneous gait and both sets of measures improved with walking age, validating use of the straight-path task as an index of development. However, a large proportion of free-play bouts were too short to permit standard gait measures, and most bouts were curved with omnidirectional steps. The high prevalence of these "non-canonical" bouts was constant over development. We propose that a focus on spontaneous walking, the phenomenon we ostensibly wish to explain, yields important insights into the problems infants solve while learning to walk. Other areas of developmental research may also benefit from retaining the complexity of complex phenomena.

Bone Mineral Content in Infants With Myelomeningocele, With and Without Treadmill Stepping Practice.

PURPOSE: To study development of bone mineral content (BMC) in infants with myelomeningocele (MMC) who did or did not receive upright supported stepping practice (USSP) and in infants with typical development (TD). METHODS: We tested 36 infants across the ages of 1 to 18 months. Dual-energy x-ray absorptiometry was used to collect raw BMC data for the whole body, legs, and arms, which were normalized using anthropometrics. RESULTS: Whole-body BMC generally increased with age; values for infants with MMC were slightly lower than those for infants with TD. Bone mineral content for legs and arms was lower for infants with MMC than for infants with TD. Between MMC groups, the group receiving USSP showed increases in BMC with age. CONCLUSION: Bone mineralization in infants with MMC begins to lag compared with infants with TD across infancy, and daily USSP can improve BMC as early as the first year of life.

Early gait development in human infants: Plasticity and clinical applications.

In this paper we focus on how a developmental perspective on plasticity in the control of human movement can promote early therapy and improve gait acquisition in infants with developmental disabilities. Current knowledge about stepping development in healthy infants across the first year of life highlights strong plasticity, both in behavioral outcome and in underlying neuro-muscular activation. These data show that stepping, like other motor skills, emerges from the interaction between infant's maturation and the environment. This view is reinforced by showing that infants with different internal resources (like genetic disorder or neural tube defect) show unique developmental trajectories when supported on a treadmill, yet do respond. Moreover, we will show that their behavior can be improved by context manipulations (mostly sensory stimulation) or practice. Overall, plasticity in the neural, skeletal, and muscle tissues create new opportunities for optimizing early intervention by creatively tapping into the same developmental processes experienced by healthy infants.

Flow-Field Inference for Turbulent Exhale Flow Measurement.

BACKGROUND: Vision-based pulmonary diagnostics present a unique approach for tracking and measuring natural breathing behaviors through remote imaging. While many existing methods correlate chest and diaphragm movements to respiratory behavior, we look at how the direct visualization of thermal CO2 exhale flow patterns can be tracked to directly measure expiratory flow. METHODS: In this work, we present a novel method for isolating and extracting turbulent exhale flow signals from thermal image sequences through flow-field prediction and optical flow measurement. The objective of this work is to introduce a respiratory diagnostic tool that can be used to capture and quantify natural breathing, to identify and measure respiratory metrics such as breathing rate, flow, and volume. One of the primary contributions of this work is a method for capturing and measuring natural exhale behaviors that describe individualized pulmonary traits. By monitoring subtle individualized respiratory traits, we can perform secondary analysis to identify unique personalized signatures and abnormalities to gain insight into pulmonary function. In our study, we perform data acquisition within a clinical setting to train an inference model (FieldNet) that predicts flow-fields to quantify observed exhale behaviors over time. RESULTS: Expiratory flow measurements capturing individualized flow signatures from our initial cohort demonstrate how the proposed flow field model can be used to isolate and analyze turbulent exhale behaviors and measure anomalous behavior. CONCLUSIONS: Our results illustrate that detailed spatial flow analysis can contribute to unique signatures for identifying patient specific natural breathing behaviors and abnormality detection. This provides the first-step towards a non-contact respiratory technology that directly captures effort-independent behaviors based on the direct measurement of imaged CO2 exhaled airflow patterns.

Natural Products for Liver Cancer Treatment: From Traditional Medicine to Modern Drug Discovery.

Primary liver cancer was the seventh most diagnosed cancer and the second leading cause of cancer death with about 906,000 cases and 830,000 deaths, respectively, in 2020. Conventional treatment for liver cancer, such as transarterial chemoembolization (TACE) or sorafenib, has limitations in that there is the recurrence of cancer, drug inefficacy, and adverse effects. Traditional medicine and natural products of several regions including Korea, China, Europe, North America, India, and the Middle East have attracted a lot of attention since they have been reported to have anticancer effects with low adverse effects. In this review, several in vivo studies on the effects of natural compounds on liver cancer and clinical trials approving their therapeutic benefits were selected and discussed. As a result of the analysis of these studies, the effects of natural compounds were classified into a few mechanisms: apoptosis, anti-metastasis, and antiangiogenesis. In addition, medications including natural products in clinical trials were observed to exhibit improvements in various liver cancer symptoms and patients' survival rates. This study presents findings suggestive of the anticancer potential of natural products and their properties in relieving related symptoms.

Preoperative hyperlactatemia and early mortality after liver transplantation: selection of important variables using random forest survival analysis.

BACKGROUND: Generally, lactate levels > 2 mmol/L represent hyperlactatemia, whereas lactic acidosis is often defined as lactate > 4 mmol/L. Although hyperlactatemia is common finding in liver transplant (LT) candidates, association between lactate and organ failures with Acute-on-chronic Liver Failure (ACLF) is poorly studied. We searched the important variables for pre-LT hyperlactatemia and examined the impact of preoperative hyperlactatemia on early mortality after LT. METHODS: A total of 2,002 patients from LT registry between January 2008 and February 2019 were analyzed. Six organ failures (liver, kidney, brain, coagulation, circulation, and lung) were defined by criteria of EASL-CLIF ACLF Consortium. Variable importance of preoperative hyperlactatemia was examined by machine learning using random survival forest (RSF). Kaplan-Meier Survival curve analysis was performed to assess 90-day mortality. RESULTS: Median lactate level was 1.9 mmol/L (interquartile range: 1.4, 2.4 mmol/L) and 107 (5.3%) patients showed > 4.0 mmol/L. RSF analysis revealed that the four most important variables for hyperlactatemia were MELD score, circulatory failure, hemoglobin, and respiratory failure. The 30-day and 90-day mortality rates were 2.7% and 5.1%, whereas patients with lactate > 4.0 mmol/L showed increased rate of 15.0% and 19.6%, respectively. CONCLUSIONS: About 50% and 5% of LT candidates showed pre-LT hyperlactatemia of > 2.0 mmol/L and > 4.0 mmol/L, respectively. Pre-LT lactate > 4.0 mmol/L was associated with increased early post-LT mortality. Our results suggest that future study of correcting modifiable risk factors may play a role in preventing hyperlactatemia and lowering early mortality after LT.

Programmed Intermittent Epidural Bolus versus Continuous Epidural Infusion in Major Upper Abdominal Surgery: A Retrospective Comparative Study.

Although recent evidence shows that the programmed intermittent epidural bolus can provide improved analgesia compared to continuous epidural infusion during labor, its usefulness in major upper abdominal surgery remains unclear. We evaluated the effect of programmed intermittent epidural bolus versus continuous epidural infusion on the consumption of postoperative rescue opioids, pain intensity, and consumption of local anesthetic by retrospective analysis of data of patients who underwent major upper abdominal surgery under ultrasound-assisted thoracic epidural analgesia between July 2018 and October 2020. The primary outcome was total opioid consumption up to 72 h after surgery. The data of postoperative pain scores, epidural local anesthetic consumption, and adverse events from 193 patients were analyzed (continuous epidural infusion: n = 124, programmed intermittent epidural bolus: n = 69). There was no significant difference in the rescue opioid consumption in the 72 h postoperative period between the groups (33.3 mg [20.0-43.3] vs. 28.3 mg [18.3-43.3], p = 0.375). There were also no significant differences in the pain scores, epidural local anesthetic consumption, and incidence of adverse events. Our findings suggest that the quality of postoperative analgesia and safety following major upper abdominal surgery were comparable between the groups. However, the use of programmed intermittent epidural bolus requires further evaluation.

Object interaction and walking: Integration of old and new skills in infant development.

Manual skills such as reaching, grasping, and exploring objects appear months earlier in infancy than locomotor skills such as walking. To what extent do infants incorporate an old skill (manual actions on objects) into the development of a new skill (walking)? We video recorded 64 sessions of infants during free play in a laboratory playroom. Infants' age (12.7-19.5 months), walking experience (0.5-10.3 months), and walking proficiency (speed, step length, etc.) varied widely. We found that the earlier developing skills of holding and exploring objects are immediately incorporated into the later developing skill of walking. Although holding incurred a reliable cost to infants' gait patterns, holding and exploring objects in hand were relatively common activities, and did not change with development. Moreover, holding objects was equally common in standing and walking. However, infants did not interact with objects indiscriminately: Object exploration was more frequent while standing than walking, and infants selectively chose lighter objects to carry and explore. Findings suggest that the earlier appearance of some skills may serve to motivate and enrich later appearing skills.

A comparison of using the DSM-5 and MABC-2 for estimating the developmental coordination disorder prevalence in Korean children.

BACKGROUND: Previous literature has shown inconsistency in the prevalence of developmental coordination disorder (DCD). The Movement Assessment Battery for Children, Second Edition (MABC-2) is often used for DCD prevalence studies, although the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) recommends four criteria. AIMS: The purpose of this study was to compare the prevalence of DCD in Korean children using the DSM-5 and MABC-2. METHODS: A total of 548 Korean elementary school students (mean age: 8.5 years ± 4.5 months) completed this study procedure. All four criteria defined by the DSM-5 were used to classify children with DCD. MABC-2 test scores were used to classify students into four subgroups: high-risk DCD, mild-risk DCD, probable DCD and typical development. RESULTS: Cohen's kappa revealed that the estimates of DCD prevalence were not significantly different between MABC-2 and DSM-5. When DSM-5 criteria were applied, 60 children out of 548 were classified as probable DCD (10.94%) compared to 70 children with probable DCD (12.77%) when MABC-2 was used. CONCLUSIONS: DCD prevalence based on DSM-5 is not significantly different from MABC-2, though it tends to estimate less than MABC-2. Future studies should consider our findings when selecting an assessment tool.

The Use of Cuff Weights for Aquatic Gait Training in People Post-Stroke with Hemiparesis.

BACKGROUND AND PURPOSE: This study aimed to examine how spatiotemporal and kinematic gait variables are influenced by the application of a cuff weight during aquatic walking in people post-stroke. The secondary purpose was to compare the differences in gait responses between the placements of cuff weights on the proximal (knee weight) and distal end (ankle weight) of the shank. METHODS: Twenty-one participants post-stroke with hemiparesis aged 66.3 ± 11.3 years participated in a cross-sectional comparative study. Participants completed two aquatic walking trials at their self-selected maximum walking speed across an 8-m walkway under each of the three conditions: 1) walking with a knee weight; 2) walking with an ankle weight; and 3) walking with no weight. Cuff weights were worn on the paretic leg of each participant. Gait speed, cadence, step width and joint kinematics of the hip, knee and ankle joints were recorded by a customized three-dimensional underwater motion analysis system. RESULTS: Mean aquatic walking speeds significantly increased with the use of cuff weights when compared to walking with no weight. Changes in gait variables were found in the non-paretic leg with the addition of weight, while no significant changes were found in the paretic leg. CONCLUSION: The results suggest that the use of additional weight can be helpful if the goal of gait training is to improve walking speed of people post-stroke during pool floor walking. However, it is interesting to note that changes in gait variables were not found in the paretic limb where favourable responses were expected to occur.

Functioning of peripheral Ia pathways in leg muscles of newly walking toddlers.

Monosynaptic and polysynaptic spinal level reflexes in the leg muscles of infants show significant dispersion across muscles, high variability, and no change in response patterns over the first 10 months. Here we tested the hypothesized relation between early walking experience and the tuning of these responses in three primary gait muscles of participants in four subgroups: cruisers (n=7) and toddlers with one (n=5), two (n=5), or three (n=5) months of walking experience. Reflex responses in multiple Ia pathways - tendon reflex (T-reflex), vibration-induced inhibition of the T-reflex (VIM-T-reflex), and tonic vibration-induced reflex (VIR), were elicited by mechanical stimuli applied to the distal tendons of the quadriceps, gastrocnemius-soleus, and tibialis anterior of both legs. Walking skill was assessed via a GAITRite mat. Generally, walking experience seemed to be related to slowly emerging improvements and, depending on muscle tested and pathway, progress was quite varied. Amplitude and latency of reflex responses were more clearly impacted by age or leg length while the ratio or distribution pattern of reflex response among antagonist pairs of muscles was impacted by walking experience and skill. As walking experience increased, the ratio of reflex responses tended to increase for the stimulated and decrease for the antagonist reflex loops with distribution of the pattern shifting gradually toward a single type of reflex response in all tested muscles. The very slow tuning of these reflexes may underlie the many missteps and falls reported to occur during early walking and suggest that subsequent studies should continue to follow the developmental trajectory through the first year of walking experience.