Pilot Study to Investigate the Benefits of the InnoSpire Go Mesh Nebulizer Compared to Jet Nebulizers in the Treatment of Stable COPD.

Background: Nebulizers are widely used for the delivery of aerosols to patients with chronic obstructive pulmonary disease (COPD). The InnoSpire Go mesh nebulizer has been designed to improve upon the ease of use and convenience of existing nebulizers for the treatment of COPD. Methods: This was a pilot, single-center, randomized, open-label crossover study conducted over 2 months to investigate the use of the InnoSpire Go mesh nebulizer compared to the patient's own compressor driven jet nebulizer in ambulatory patients with stable COPD. Patient preference was assessed at the end of the study; quality of life, symptom scores, treatment time, and satisfaction were assessed at multiple points during the study. Results: Data for 17 patients were eligible for analysis, patients had a mean age of 64.6 years, and 64.7% were graded 3 on the modified Medical Research Council dyspnea scale. All patients preferred the InnoSpire Go mesh nebulizer over their own compressor driven jet nebulizer (p < 0.001). Nebulization of study drugs using the InnoSpire Go mesh nebulizer was associated with statistically significant increases in health-related quality of life over baseline (Dyspnea p = 0.003, Emotion p = 0.043, Mastery p = 0.011). A mixed model analysis of Borg dyspnea scores before and after exercise showed significantly (p = 0.043) lower scores for the InnoSpire Go mesh nebulizer compared with the compressor driven nebulizers. Patient satisfaction was statistically significantly higher for each of 10 questions covering ease of use, confidence, burden of use, satisfaction, and how well the device fit into their lifestyle. Treatment time was significantly shorter with the InnoSpire Go mesh nebulizer (p = 0.003). Conclusions: Patients preferred and were more satisfied with the InnoSpire Go mesh nebulizer. Nebulization of study drugs using the InnoSpire Go mesh nebulizer resulted in improved quality of life compared with baseline, and treatments were delivered in a shorter period than the compressor driven jet nebulizers. Clinical Trial Registration number: ClinicalTrials.gov: NCT03933462.

Estimating sleep stages using cardiorespiratory signals: validation of a novel algorithm across a wide range of sleep-disordered breathing severity.

STUDY OBJECTIVES: We have developed the CardioRespiratory Sleep Staging (CReSS) algorithm for estimating sleep stages using heart rate variability and respiration, allowing for estimation of sleep staging during home sleep apnea tests. Our objective was to undertake an epoch-by-epoch validation of algorithm performance against the gold standard of manual polysomnography sleep staging. METHODS: Using 296 polysomnographs, we created a limited montage of airflow and heart rate and deployed CReSS to identify each 30-second epoch as wake, light sleep (N1 + N2), deep sleep (N3), or rapid eye movement (REM) sleep. We calculated Cohen's kappa and the percentage of accurately identified epochs. We repeated our analyses after stratification by sleep-disordered breathing (SDB) severity, and after adding thoracic respiratory effort as a backup signal for periods of invalid airflow. RESULTS: CReSS discriminated wake/light sleep/deep sleep/REM sleep with 78% accuracy; the kappa value was 0.643 (95% confidence interval, 0.641-0.645). Discrimination of wake/sleep demonstrated a kappa value of 0.711 and accuracy of 89%, non-REM sleep/REM sleep demonstrated a kappa of 0.790 and accuracy of 94%, and light sleep/deep sleep demonstrated a kappa of 0.469 and accuracy of 87%. Kappa values did not vary by more than 0.07 across subgroups of no SDB, mild SDB, moderate SDB, and severe SDB. Accuracy increased to 80%, with a kappa value of 0.680 (95% confidence interval, 0.678-0.682), when CReSS additionally utilized the thoracic respiratory effort signal. CONCLUSIONS: We observed substantial agreement between CReSS and the gold-standard comparator of manual sleep staging of polysomnographic signals, which was consistent across the full range of SDB severity. Future research should focus on the extent to which CReSS reduces the discrepancy between the apnea-hypopnea index and the respiratory event index, and the ability of CReSS to identify REM sleep-related obstructive sleep apnea.

Acoustic enhancement of slow wave sleep on consecutive nights improves alertness and attention in chronically short sleepers.

INTRODUCTION: Chronic sleep restriction has been linked to occupational errors and motor vehicle crashes. Enhancing slow wave sleep may alleviate some of the cognitive deficits associated with chronic sleep restriction. However, the extent to which acoustic stimulation of slow wave activity (SWA) may improve alertness and attention is not well established, particularly with respect to consecutive nights of exposure. METHODS: Twenty-five healthy adults (32.9 ± 8.2 years; 16 female) who self-restricted their sleep during workdays participated in a randomized, double-blind, cross-over study. Participants wore an automated acoustic stimulation device for two consecutive nights. Acoustic tones (50 ms long) were delivered on the up-phase of the slow wave first and then at constant 1-s inter-tone-intervals once N3 was identified (STIM), until an arousal or shift to another sleep stage occurred, or at inaudible decibels during equivalent stimulation periods (SHAM). Subjective alertness/fatigue (KSS, Samn-Perelli) was assessed across both days, and objective measures of alertness (MSLT) and attention (PVT) were assessed after two nights of stimulation. RESULTS: After one night of acoustic stimulation, increased slow wave energy was observed in 68% of participants, with an average significant increase of 17.7% (p = 0.01), while Night 2 was associated with a 22.2% increase in SWA (p = 0.08). SWE was highly stable across the two nights of STIM (ICC 0.93, p < 0.001), and around half (56%) of participants were consistently classified as responders (11/25) or non-responders (3/25). Daytime testing showed that participants felt more alert and awake following each night of acoustic stimulation (p < 0.05), with improved objective attention across the day following two nights of acoustic stimulation. DISCUSSION: Consecutive nights of acoustic stimulation enhanced SWA on both nights, and improved next day alertness and attention. Given large individual differences, we highlight the need to examine both the long-term effects of stimulation, and to identify inter-individual differences in acoustic stimulation response. Our findings suggest that the use of an acoustic device to enhance slow wave sleep may alleviate some of the deficits in alertness and attention typically associated with sleep restriction.

Closed-loop system to enhance slow-wave activity.

OBJECTIVE: Recent evidence reports cognitive, metabolic, and sleep restoration benefits resulting from the enhancement of sleep slow-waves using auditory stimulation. Our objective is to make this concept practical for consumer use by developing and validating an electroencephalogram (EEG) closed-loop system to deliver auditory stimulation during sleep to enhance slow-waves. APPROACH: The system automatically detects slow-wave sleep with 74% sensitivity and 97% specificity and optimally delivers stimulation in the form of 50 ms-long tones separated by a constant one-second inter-tone interval at a volume that is dynamically modulated such that louder tones are delivered when sleep is deeper. The system was tested in a study involving 28 participants (18F, 10M; 36.9 ± 7.3 years old; median age: 40 years old) who used the system for ten nights (five nights in a sham condition and five in a stimulation condition). Four nights in each condition were recorded at-home and the fifth one in-lab. MAIN RESULTS: The analysis in two age groups defined by the median age of participants in the study shows significant slow wave activity enhancement (+16.1%, p < 0.01) for the younger group and absence of effect on the older group. However, the older group received only a fraction (57%) of the stimulation compared to the younger group. Changes in sleep architecture and EEG properties due to aging have influenced the amount of stimulation. The analysis of the stimulation timing suggests an entrainment-like phenomenon where slow-waves align to the stimulation periodicity. In addition, enhancement of spindle power in the stimulation condition was found. SIGNIFICANCE: We show evidence of the viability of delivering auditory stimulation during sleep, at home, to enhance slow wave activity. The system ensures the stimulation delivery to be at the right time during sleep without causing disturbance.

Revision extensor mechanism allografting after total knee arthroplasty.

This study analyzed the outcomes of revision extensor mechanism allografting (EMA) in 8 patients with failures of previous EMA after total knee arthroplasty. Fresh-frozen allografts were used. Knee Society Clinical Rating System (KSS) scores were used to measure clinical outcomes, with special attention given to presence of extensor lag and assistive ambulatory devices. Patients were observed for an average of 3.1 years. Two patients were considered failures due to infection within the first postoperative year of the revision EMA. In the remaining 6 patients, the average KSS score at most recent follow-up showed no improvement when compared with preoperative scores. Revisions of the failed EMA resulted in a high incidence of functional limitations, which continue to deteriorate over time.

Anthropomorphic differences between the distal femora of men and women.

There is debate about whether distinct designs of femoral components for men and women are needed based on morphologic and size differences between genders. We asked whether anthropomorphic differences exist between the distal femoral dimensions in women and men. We measured the distal femora of 100 women and 100 men intraoperatively after preparation for prosthetic implantation. The measured dimensions included the anteroposterior height from the posterior edge of the medial femoral condyle to the flush anterior cut, the mediolateral width at the transepicondylar axis, the anterior and posterior edges of the anterior chamfer, and the medial and lateral trochlear flanges. These measurements were compared between genders using independent-samples t test. The aspect ratio (a measure of the shape of the distal femur), the ratio between the anteroposterior and mediolateral dimensions, was calculated for men and women to determine whether there is a shape difference between genders. The mean aspect ratio was larger for women than for men (0.84 [range, 0.57-1.03] versus 0.81 [range, 0.066-1.34], respectively). The standard deviation and range of each measurement of size and morphology suggest variability not only between genders but also within genders. Whether the aspect ratios and variations will reflect clinically important differences in outcomes after TKA with available prostheses will require additional study.

Morbidity of sequential bilateral revision TKA performed under a single anesthetic.

UNLABELLED: There are little data reporting perioperative morbidity and postoperative complications of bilateral sequential revision total knee arthroplasties (TKAs) performed in one anesthetic setting. We retrospectively reviewed 49 patients undergoing 51 complete (tibial and femoral components) bilateral revision TKAs under a single anesthetic between 1999 and 2006. The average age was 65 years; the minimum followup was 1 month (average, 12 months; range, 1-38 months). Comorbidities included cardiovascular (n = 32), pulmonary (n = 13), endocrine (n = 22), gastrointestinal (n = 30), and neurologic (n = 18). Average surgical time was 64 minutes per limb. Six patients received no stems, six received two stems, two patients received three stems, and 37 received four stems. We encountered no intraoperative complications and no patients with postoperative cardiovascular compromise, stroke, or death. Postoperative complications included confusion in three patients, one pulmonary embolism treated successfully with extended anticoagulation, one patient with posterior compartment syndrome treated with fasciotomy, and one with bilateral stiffness who underwent manipulation under anesthesia at 3 months. In our patients the perioperative medical risks of bilateral TKA performed under a single anesthetic were low, even with the use of stemmed components. LEVEL OF EVIDENCE: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Incidence of patellar clunk with a modern posterior-stabilized knee design.

Patellar clunk is an uncommon complication of posterior-stabilized total knee arthroplasty (TKA), though the incidence has been reported to be as high as 7.5% with some posterior-stabilized implants, and the etiology is multifactorial. Femoral component design has been implicated as a major cause of this complication. This series compares the incidence of patellar clunk with 2 different knee prostheses, the Insall-Burstein II (IB) and the NexGen Legacy PS (NG), both manufactured by Zimmer (Warsaw, Ind). One-hundred fifty consecutive posterior-stabilized TKAs were in each group, and the groups were similar in surgical approaches and techniques. Insall-Salvati (IS) ratios and joint-line positions were measured on preoperative and postoperative x-rays. Knee Society Clinical and Functional scores were calculated. Incidence of patellar clunk was reduced from 4% with the IB design to 0% with the NG design. IS ratios, joint-line positions, and clinical outcomes were no different between the groups. It appears that femoral component design may play a substantial role in development of patellar clunk after posterior-stabilized TKA.

Revision of a failed patellofemoral arthroplasty to a total knee arthroplasty.

BACKGROUND: Patellofemoral arthroplasty is an effective treatment for isolated arthritis of the anterior compartment of the knee, but it is unclear whether it compromises the results of total knee arthroplasty if revision is necessary. The purpose of this study was to review the results of total knee arthroplasty after a prior patellofemoral arthroplasty. METHODS: Twelve failed patellofemoral replacements in ten patients were revised to total knee arthroplasties for isolated progressive tibiofemoral arthritis (six knees), isolated patellofemoral catching and maltracking (three), or a combination of both (three). Revisions were performed at a mean of four years after the patellofemoral arthroplasty. A posterior stabilized implant was used in each knee, without a need for stems, augments, or structural bone graft. Patients were assessed by clinical and radiographic follow-up, including Knee Society clinical and functional scores. Baseline preoperative Knee Society scores were obtained at the time of evaluation of the failed patellofemoral arthroplasty. RESULTS: At a mean follow-up of 3.1 years, the mean Knee Society clinical and functional scores had increased from 57 points preoperatively to 96 points and from 51 points preoperatively to 91 points, respectively. At the most recent follow-up, there was no clinical or radiographic evidence of patellofemoral maltracking, loosening, or wear. CONCLUSIONS: On the basis of our experience in this relatively small series with short-term follow-up, the results of total knee arthroplasty do not seem to be compromised after revision of the failed patellofemoral replacement.

The influence of dynamic visual cues for postural control in children aged 7-12 years.

Young children rely heavily on vision for postural control during the transition to walking. Although by 10 years of age, children have automatic postural responses similar to adults, it is not clear when the integration of sensory inputs becomes fully developed. The purpose of this study was to examine this transition in the sensory integration process in children aged 7-12 years. Healthy children and adults stood on a fixed or sway-referenced support surface while viewing full-field optic flow scenes that moved sinusoidally (0.1 and 0.25 Hz) in an anterior-posterior direction. Center of pressure was recorded, and measures of sway amplitude and phase were calculated at each stimulus frequency. Children and adults had significant postural responses during approximately two-thirds of the trials. In adults, there was a 90% decrease in sway on the fixed surface compared with the sway-referenced surface, but only a 50% decrease in children. The phase between the optic flow stimulus and postural response in children led that of adults by 52 degrees at 0.1 Hz and by 15 degrees at 0.25 Hz. Adults and children aged 7-12 years have similar ability to use dynamic visual cues for postural control. However, 7-12-year-old children do not utilize somatosensory cues to stabilize posture to the same extent as adults when visual and somatosensory cues are conflicting.