Pre-Extubation Ultrasound Measurement of In Situ Cuffed Endotracheal Tube Laryngeal Air Column Width Difference: Single-Center Pilot Study of Relationship With Post-Extubation Stridor in Subjects Younger Than 5 Years Old.

OBJECTIVES: Post-extubation stridor (PES) is difficult to predict before extubation. We therefore evaluated the potential diagnostic performance of pre-extubation laryngeal air column width difference (LACWD) measurement, as assessed by intensivist-performed point-of-care laryngeal ultrasound, in relation to clinically important PES. DESIGN: Prospective observational cohort study. SETTING: Single quaternary care PICU (July 19, 2021, to October 31, 2022). PATIENTS: Included subjects were younger than 5 years old, intubated with a cuffed endotracheal tube, requiring invasive mechanical ventilation for greater than 24 hours, and nearing extubation. Subjects at high risk for supraglottic airway obstruction were excluded. INTERVENTIONS: Laryngeal ultrasound with measurement of laryngeal air column width with the endotracheal tube cuff inflated and deflated. Clinically important PES was defined as a high-pitched inspiratory respiratory noise suspected to be from a subglottic focus necessitating received medical intervention or reintubation. MEASUREMENTS AND MAIN RESULTS: Among 53 enrolled subjects, 18 of 53 (34%) experienced PES and three of 53 (6%) were reintubated because of severe subglottic upper airway obstruction. Median LACWD was significantly lower in the stridor group compared with the nonstridor group (∆ 0.41 mm; 95% CI, 0.37-0.48; p < 0.001). The area under the receiver operating characteristic curve for LACWD as a diagnosis of PES was 0.94 (95% CI, 0.89-1.00; p < 0.001). The LACWD cutoff for PES was less than or equal to 0.47 mm, which yielded a diagnostic sensitivity of 91.4% and specificity of 88.9%. In this population, the pre-to-post-test change in probability of PES for LACWD less than or equal to 0.47 mm is 0.34 to 0.81. CONCLUSIONS: Pre-extubation LACWD is a novel, noninvasive assessment that can be performed and interpreted by the intensivist at the bedside. There is, however, diagnostic uncertainty in the use of this measurement for identifying those at-risk of PES and larger validation studies are needed.

Pediatric ventilation liberation: evaluating the role of endotracheal secretions in an extubation readiness bundle.

BACKGROUND: An evidence gap exists regarding the role of endotracheal secretions in pediatric extubation decisions. This study aims to evaluate whether endotracheal secretion burden independently correlates with pediatric extubation failure. METHODS: This is a single-center, prospective cohort study of children aged <19 years requiring intubation. Nurses (RN) and respiratory therapists (RT) independently used a novel secretion assessment score focusing on secretion volume, character, and trend. We hypothesized that the RN and RT secretion scores would not correlate with extubation outcome and inter-rater reliability would be poor. RESULTS: RN secretion character sub-score (OR 3.3, 95% CI 1.1-11.1, p = 0.048) was independently associated with extubation failure. RN and RT inter-rater reliability was poor (correlation 0.385, 95% CI 0.339-0.429, p < 0.001). A failure prediction model incorporating the RN secretion character sub-score as well as indication for mechanical ventilation and spontaneous breathing trial result demonstrated an area under the receiver operating curve of 0.817 (95% CI 0.730-0.904, p < 0.001). CONCLUSIONS: In the general pediatric population, the RN assessment of endotracheal secretion character was independently associated with extubation failure. A model incorporating indication for mechanical ventilation, spontaneous breathing result, and RN assessment of endotracheal secretion character demonstrated reasonable accuracy in predicting failure in those clinically selected for extubation. IMPACT: Development of comprehensive and sensitive extubation readiness bundles are key to balancing the competing risks of prolonged invasive mechanical ventilation duration and extubation failure. Evidence for clinical factors linked to extubation outcomes in children are limited. Endotracheal secretion burden is a common factor considered but has not been studied. This study supports a role for endotracheal secretion burden, as assessed by the bedside nurse, in extubation readiness bundles. Inter-rater reliability with respiratory therapists was poor. A model incorporating other key factors showed good discrimination for extubation outcome and sets the stage for prospective evaluation in the general population and diagnosis-specific subgroups.

A Respiratory Therapist-Driven Pathway Improves Timeliness of Extubation Readiness Assessment in a Single PICU.

OBJECTIVES: Our smart aim was to decrease the time between when a mechanically ventilated patient was eligible for and when they underwent their first extubation readiness test (delta time) by 50% within 3 months through the development and implementation of a respiratory therapist-driven extubation readiness test pathway. DESIGN: Quality improvement project. SETTING: Single, tertiary care, 24-bed, academic PICU. PATIENTS: Pediatric patients admitted to the PICU and requiring mechanical ventilation for a primary pulmonary process. INTERVENTIONS: We developed an extubation readiness test pathway that consisted of an eligibility screen and a standard testing process. Patients were screened every 3 hours. Upon passing the screen and being cleared by a prescriber, a test was initiated. No clinical management was dictated to prescribers. MEASUREMENTS AND MAIN RESULTS: The preintervention and intervention cohorts included 109 and 43 mechanical ventilation courses, respectively. The mean delta time decreased from 33.77 hours to 2.92 hours after pathway implementation (p = 0.000). The medical length of stay decreased from 196.6 to 177.2 hours (p = 0.05). There were no statistically significant changes in duration of mechanical ventilation until first extubation (112.9 vs 122.3 hr; p = 0.651) and 48-hour extubation failure rate (16.5% vs 4.8%; p = 0.056). The sensitivity and positive predictive value for the extubation readiness test were 89.5% and 94.4%, respectively. The mean for all process compliance measures was 91.5%. CONCLUSIONS: A respiratory therapist-driven extubation readiness test pathway can be safely implemented in a large, academic PICU. The pathway resulted in earlier extubation readiness testing without increasing key balancing measures-the duration of mechanical ventilation, PICU length of stay, or the extubation failure rate.

Clinically-relevant cardiopulmonary interactions for the pediatric intensivist.

A thorough understanding of cardiorespiratory interactions is essential when caring for critically ill children. These interactions are linked to changes in intrathoracic pressure and their impact on cardiac preload and afterload. The predominant effect of positive-pressure ventilation in children with normal cardiac function is to decrease preload to the right heart with an eventual decrease in left ventricular stroke volume. This can be anticipated and mitigated by judicious fluid resuscitation. The effect of positive-pressure ventilation on right heart afterload is more complex and variable depending on lung volume. In patients with diminished left ventricular contractility, positive pressure reduces afterload to the left heart, significantly improving stroke volume. Monitoring of cardiorespiratory interactions in critically ill children is beneficial in assessing volume status and predicting fluid responsiveness.

Differential Modulation of Endophytic Microbiome of Ginger in the Presence of Beneficial Organisms, Pathogens and Both as Identified by DGGE Analysis.

Endophytic microorganisms play a significant role in plants response to beneficial organisms and pathogens. In the current study, endophytic microorganisms from Zingiber officinale were screened for in vitro inhibition against Pythium myriotylum. From this, Burkholderia vietnamiensis ZoB74 was selected as an organism with remarkable antifungal effect. Further, the study focussed on analysis of in vivo changes in endophytic bacterial community of Z. officinale in presence of selected organisms and the pathogen P. myriotylum by PCR-DGGE. 16S rDNA sequencing of bacterial community after DGGE has resulted in the identification of a group of uncultured bacteria as the predominant microbial community of rhizome under various conditions of treatment. High frequency dominance of these endophytic bacteria suggests their role in disease resistance to soft rot in ginger. This also revealed the variation of endophytic microbiome of Z. officinale under biotic stress. Hence the study provides molecular insight into uncultured microbiome and its stress-inducible variation in ginger rhizome.

Ventilator graphics.

Providing optimal mechanical ventilation to critically-ill children remains a challenge. Patient-ventilator dyssynchrony results frequently with numerous deleterious consequences on patient outcome including increased requirement for sedation, prolonged duration of ventilation, and greater imposed work of breathing. Most currently used ventilators have real-time, continuously-displayed graphics of pressure, volume, and flow versus time (scalars) as well as pressure, and flow versus volume (loops). A clear understanding of these graphics provides a lot of information about the mechanics of the respiratory system and the patient ventilator interaction in a dynamic fashion. Using this information will facilitate tailoring the support provided and the manner in which it is provided to best suit the dynamic needs of the patient. This paper starts with a description of the scalars and loops followed by a discussion of the information that can be obtained from each of these graphics. A review will follow, on the common types of dyssynchronous interactions and how each of these can be detected on the ventilator graphics. The final section discusses how graphics can be used to optimize the ventilator support provided to patients.

Simulating natural light and temperature cycles in the laboratory reveals differential effects on activity/rest rhythm of four Drosophilids.

Recent studies under semi-natural conditions have revealed various unique features of activity/rest rhythms in Drosophilids that differ from those under standard laboratory conditions. An additional afternoon peak (A-peak) has been reported for Drosophila melanogaster and another species D. malerkotliana while D. ananassae exhibited mostly unimodal diurnal activity. To tease apart the role of light and temperature in mediating these species-specific behaviours of four Drosophilid species D. melanogaster, D. malerkotliana, D. ananassae, and Zaprionus indianus we simulated gradual natural light and/or temperature cycles conditions in laboratory. The pattern observed under semi-natural conditions could be reproduced in the laboratory for all the species under a variety of simulated conditions. D. melanogaster and D. malerkotliana showed similar patterns where as D. ananassae consistently exhibited predominant morning activity under almost all regimes. Z. indianus showed clearly rhythmic activity mostly when temperature cycles were provided. We find that gradually changing light intensities reaching a sufficiently high peak value can elicit A-peak in D. melanogaster, D. malerkotliana, and D. ananassae even at mild ambient temperature. Furthermore, we show that high mid-day temperature could induce A-peak in all species even under constant light conditions suggesting that this A-peak is likely to be a stress response.

3D Bilayered Hydrogel and Nanofiber Multifunctional Sponge Dressing: An Efficacious Healing Agent for Chronic Wound Healing.

Chronic wound management using biomaterial-based dressings has significantly impacted the standard and efficiency of wound healing. However, various available wound healing aids are ineffective in treating deep open injuries and chronic wounds such as diabetic wounds. Herein, we developed a 3D bilayered multifunctional sponge, which addresses the structural and functional issues faced by biomaterial dressings in treating deep and chronic wounds. The 3D bilayered sponge consists of a hydrogel base functionalized with wound healing peptide (Tylotoin)-carrying nanoparticles and topped with a nanofiber layer functionalized with an antimicrobial peptide (LLKKK18). The 3D bilayered sponge, with its highly porous, elastic, and enhanced fluid absorption ability, makes it a suitable wound treatment aid. The developed multifunctional 3D sponge shows antibacterial action and promotes a microenvironment similar to the extracellular matrix (ECM) in regulating dermal cell survival and migration. Study in a full-thickness skin defect diabetic mouse model has shown that the developed 3D bilayered sponge accelerated wound closure and promoted functional skin regeneration through reduced inflammation, faster granulation tissue formation, re-epithelialization, neovascularization, and skin appendage restoration, which make the developed 3D bilayered multifunctional sponge an efficient and advanced chronic wound management aid with potential for future clinical application.

Insights into differential activity patterns of drosophilids under semi-natural conditions.

We showed recently that Drosophila ananassae, a closely related and sympatric species of the commonly studied fruitfly D. melanogaster, shows distinctly deviant patterns in circadian activity/rest rhythm from the latter under a variety of laboratory conditions. To examine whether such differences extend to more natural conditions where a variety of time cues and similar environmental pressures might force different species to adopt similar temporal patterns, we examined these two species under semi-natural conditions over a span of 1.5 years. Furthermore, we asked to what extent features of activity/rest rhythm of flies are conserved across species under changing environmental conditions encountered across seasons, and to do so, we studied two more drosophilid species. We found that while each species exhibits seasonality in activity patterns, this seasonality is marked by interesting inter-specific differences. Similar to laboratory studies, D. ananassae showed activity mostly during the day, while D. melanogaster and D. malerkotliana exhibited almost similar activity patterns across seasons, with predominantly two peaks of activity, one in the morning and another in the evening. Throughout the year, Zaprionus indianus displayed very low levels of activity compared with D. melanogaster, yet, compared with those seen in standard laboratory assays, this species exhibited more robust rhythms under semi-natural conditions. We hypothesise that different ecological factors may have influenced these species to adopt different temporal niches.