Exploring the needs of healthcare workers receiving psychological first aid during the COVID19 pandemic.

BACKGROUND: Healthcare workers (HCW; e.g., nurses, social workers) work in stressful conditions, a situation that has been further exacerbated by the COVID-19 pandemic. A review of the supportive role of Psychological first aid (PFA) suggested that it can protect HCW from psychological distress. Despite the growing interest of PFA among public health organizations, there is a dearth of literature on its potential impact for the psychological well-being of HCW and its implementation within organizations. OBJECTIVE: This study aimed to evaluate whether PFA met the psychological needs of HCW in Montreal, Quebec. METHODS: A sample of 15 HCW who received PFA by a peer within their organization were recruited to participate in semi-structured interviews. Qualitative research using thematic analysis was conducted. RESULTS: Five themes were identified: 1) PFA satisfied participants' psychosocial needs; 2) PFA provided by peers allowed participants to feel understood and supported; 3) High availability and multiple modalities facilitated PFA access; 4) Occupational and organizational cultures hindered PFA access; and 5) Recommendations to promote the use of the PFA service. CONCLUSION: Results describe four psychosocial needs met by the PFA intervention: to have resources/strategies, to be validated, to obtain a better understanding of the psychological reactions they were experiencing, and to be guided and supported in their difficulties at work. Overall, these findings illustrate how PFA goes beyond the reduction of distress symptoms in the aftermath of a potentially traumatic event. The relevance to further the assessment of PFA's positive effects on psychological adaptation and/or recovery is also highlighted.

A feasibility study of psychological first aid as a supportive intervention among police officers exposed to traumatic events.

Introduction: Police officers are often exposed to traumatic events, which can induce psychological distress and increase the risk of developing post-traumatic stress injuries. To date, little is known about support and prevention of traumatic events in police organizations. Psychological first aid (PFA) has been promoted as a promising solution to prevent psychological distress following exposure to a traumatic event. However, PFA has not yet been adapted to policing reality, let alone to the frequent exposure to traumatic events faced by this population. This study aimed to evaluate the feasibility of PFA as an early intervention for the prevention of post-traumatic stress injuries among police officers in Quebec, Canada. Specifically, the objectives were to evaluate: (1) the demand. (2) the practicality, and (3) the acceptability of PFA in a police organization. Methods: A feasibility study was conducted to evaluate the implementation of PFA among Quebec's provincial police force. To do so, 36 police officers participated in semi-structured interviews between October 26th, 2021, and July 23rd, 2022. Participants were comprised of responders (n = 26), beneficiaries (n = 4) and managers (n = 6). Interviews were transcribed, coded, and evaluated according to a thematic analysis. Results: Eleven themes emerged from participants' responses. Results suggested that PFA met individual and organizational needs. References were also made regarding the impacts of this intervention. Moreover, participants provided feedback for improving the implementation and sustainability of a PFA program. All three groups of participants shared similar thematic content. Discussion: Findings revealed that implementation of a PFA program in a law enforcement agency was feasible and could be accomplished without major issues. Importantly, PFA had beneficial consequences within the organization. Specifically, PFA destigmatized mental health issues and renewed a sense of hope among police personnel. These findings are in line with previous research.

Heliox administration in anesthetized rabbits with spontaneous inspiratory flow limitation.

We investigated the effects of heliox administration (80% helium in O2) on tidal inspiratory flow limitation (tIFL) occurring in supine anesthetized spontaneously breathing rabbits, regarded as an animal model of obstructive apnea-hypopnea syndrome. 22 rabbits were instrumented to record oro-nasal mask flow, airway opening, tracheal and esophageal pressures, and diaphragm and genioglossus electromyographic activities while breathing either room air or heliox, and, in 12 rabbits, also during the application of continuous positive airway pressure (CPAP; 6 cmH2O). For the group, heliox increased peak inspiratory flow, ventilation (18 ± 11%), peak inspiratory tracheal and dynamic transpulmonary pressures, but in no animal eliminated tIFL, as instead CPAP did in all. Muscle activities were unaffected by heliox. In the presence of IFL the increase in flow with heliox (ΔV̇ifl) varied markedly among rabbits (2 to 49%), allowing the distinction between responders and non-responders. None of the baseline variables discriminated responders and non-responders. However, fitting the Rohrer equation (R = K1 + K2V̇) to the tracheal pressure-flow relationship over the first 0.1 s of inspiration while breathing air allowed such discrimination on the basis of larger K2 in responders (0.005 ± 0.002 versus 0.002 ± 0.001 cmH2O·s2·ml-2; P < 0.001), suggesting a corresponding difference in the relative contribution of laminar and turbulent flow. The differences in ΔV̇ifl between responders and non-responders were simulated by modeling the collapsible segment of the upper airways as a non-linear resistor and varying its pressure-volume curve, length, and diameter, thus showing the importance of mechanical and geometrical factors in determining the response to heliox in the presence of tIFL.NEW & NOTEWORTHY In an obstructive sleep apnea rabbit model, heliox never abolishes tidal inspiratory flow limitation (IFL), but increases inspiratory flow and tidal volume, substantially in some and nearly nil in other animals. Positive response to heliox cannot be predicted on the basis of breathing pattern characteristics or upper airway resistance that preceded IFL onset, but is related to the mechanical and geometrical features of upper airway collapsible segment, as indicated by model simulation.

Sternum length and rib cage dimensions compared with bodily proportions in adults with cystic fibrosis.

BACKGROUND: A greater structural expansion of the rib cage in females compared with males has been described in cystic fibrosis (CF) patients; however, conflicting data exist as to whether an elongation of the bony ribs and sternum contributes to this expansion. OBJECTIVES: To compare height-adjusted anthropometric measures and sternum length between a group of normal subjects and a group of CF patients of both sexes. METHODS: Anthropometric measurements including body weight, height, upper and lower limb lengths, biacromial distance and pelvic width were measured in the standing position in 30 CF patients (13 males) and 28 normal subjects (14 males). Body surface measurements of anterior-posterior and lateral diameters of the rib cage at functional residual capacity, and sternum length were also obtained. RESULTS: Compared with normal subjects, CF patients had lower body weight, shorter standing height and shorter height-adjusted upper and lower limb lengths. Rib cage diameters were greater in CF patients than in normal subjects of either sex, but height-adjusted sternum length was not different. CONCLUSION: Significant differences in bodily proportions were found between normal subjects and CF patients, suggesting a differential growth pattern for the trunk and limbs. However, increased rib cage dimensions with lung hyperinflation and airway obstruction was not associated with an elongation of the sternum.

Use of chlorophyll a fluorescence to detect the effect of microcystins on photosynthesis and photosystem II energy fluxes of green algae.

The phenomenon of cyanobacteria bloom occurs widely in lakes, reservoirs, ponds and slow flowing rivers. Those blooms can have important repercussions, at once on recreational and commercial activities but also on the health of animals and human beings. Indeed, many species are known to produce toxins which are released in water mainly at cellular death. The cyanotoxin most frequently encountered is the microcystin (MC), a hepatotoxin which counts more than 70 variants. The use of fast tests for the detection of this toxin is thus a necessity for the protection of the ecosystems and the human health. A promising method for their detection is a bioassay based on the chlorophyll a fluorescence of algae. Many studies have shown that algae are sensible to diverse pollutants, but were almost never used for cyanotoxins. Therefore, our goals were to evaluate the effect of microcystin on the fluorescence of different species of algae and how it can affect the flow of energy through photosystem II. To reach these objectives, we exposed four green algae (Scenedesmus obliquus CPCC5, Chlamydomonas reinhardtii CC125, Pseudokirchneriella subcapitata CPCC37 and Chlorella vulgaris CPCC111) to microcystin standards (variants MC-LF, LR, RR, YR) and to microcystin extracted from Microcystis aeruginosa (CPCC299), which is known to produce mainly MC-LR. Chlorophyll a fluorescence was measured by PEA (Plant Efficiency Analyzer) and LuminoTox. The results of our experiment showed that microcystins affect the photosynthetic efficiency and the flow of energy through photosystem II from 0.01 µg/mL, within only 15 min. From exposure to standard of microcystin, we showed that MC-LF was the most potent variant, followed by MC-YR, LR and RR. Moreover, green algae used in this study demonstrated different sensitivity to MCs, S. obliquus being the more sensitive. We finally demonstrated that LuminoTox was more sensitive to MCs than parameters measured with PEA, although the latter brings indication on the mode of action of MCs at the photosynthetic apparatus level. This is the first report showing a photosynthetic response within 15 min of exposure. Our results suggest that bioassay based on chlorophyll fluorescence can be used as a rapid and sensitive tool to detect microcystin.

The Epworth Sleepiness Scale: self-administration versus administration by the physician, and validation of a French version.

BACKGROUND/OBJECTIVES: The Epworth Sleepiness Scale (ESS) measures sleepiness and is used for, among others, patients with obstructive sleep apnea (OSA). The questionnaire is usually self-administered, but may be physician administered. The aim was to compare the two methods of administration and to validate a French version. METHODS: Consecutive patients presenting to the sleep clinic at a tertiary care centre completed a self-administered questionnaire containing the ESS. During the medical interview the same day, one of three pulmonologists who specialized in sleep medicine administered the ESS. Correlations with the apnea-hypopnea index and mean sleep latencies were used to assess construct validity, while results of previous self-administered ESS questionnnaires in untreated and recently treated OSA patients were used to test reproducibility and longitudinal construct validity, respectively. RESULTS: In OSA patients, the ESS weakly correlated with the apnea-hypopnea index (r=0.224; P=0.05; n=120) and negatively with mean sleep latency. For untreated patients (test-retest), the mean (+/- SD) average score was unchanged (10.3+/-6.0 to 10.8+/-6.5; P=0.35; n=56) after a median of seven months. With continuous positive airway pressure use, the mean score decreased from 12.4+/-6.8 to 7.6+/-5.0 after 40.2 months (P<0.0001; n=68). For all subjects, the ESS score obtained by the physician was less than that of the self-administered result (9.4+/-5.9 versus 8.5+/-5.8; P<0.0001 [paired t test]; n=188). CONCLUSIONS: In a sleep clinic population, the French version of the ESS performed similarly to the English version. However, the systematic underscoring during physician administration may be important to consider in the research setting if questionnaire administration methods are not consistent.

Estimated prevalence of obstructive sleep apnea-hypopnea syndrome after cervical cord injury.

OBJECTIVES: To estimate the prevalence of obstructive sleep apnea-hypopnea syndrome (OSAHS) in patients with cervical cord injury and to identify predictive factors. DESIGN: Cross-sectional study. SETTING: Rehabilitation center. PARTICIPANTS: Forty-one adults with cervical cord injury of more than 6 months in duration. INTERVENTIONS: Medical history, physical exam, and full in home overnight polysomnography were undertaken. Data were collected on characteristics of spinal cord injury, current medication, sleeping habits, daytime sleepiness, body mass index (BMI), and neck circumference. MAIN OUTCOME MEASURE: Presence or absence of OSAHS as defined by the American Academy of Sleep Medicine criteria (1999). RESULTS: Twenty-two (53%) patients (95% confidence interval [CI], 38.4%-68.9%) had OSAHS. Daytime sleepiness (odds ratio [OR], 41.1; 95% CI, 2.3-739.7; P=.02), BMI of 30 kg/m2 or higher (OR=17.2; 95% CI, 1.4-206.4; P=.03), and 3 or more awakenings during sleep (OR=34; 95% CI, 1.6-744.8; P=.03) were the best predictive factors of OSAHS obtained by a forward stepwise multiple logistic regression. CONCLUSIONS: The estimated prevalence of OSAHS is high after cervical cord injury. OSAHS should be suspected, especially in patients with daytime sleepiness, obesity, and frequent awakenings during sleep.

Combined use of photosynthetic enzyme complexes and microalgal photosynthetic systems for rapid screening of wastewater toxicity.

Because of the often episodic nature of wastewater toxicity, routine monitoring using expensive and time consuming tests can constitute an inefficient means of toxicity evaluation, particularly when negative results are generated. Cost-effective screening tests enabling the rapid detection of effluent toxicity are clearly needed, and they should be used to rapidly determine where in-depth investigations should be focused. The LuminoTox is a recently-developed screening test enabling the rapid determination of wastewater toxicity. This test is based on the inhibition of chlorophyll fluorescence emitted by photosynthetic systems. The combined use of photosynthetic enzyme complexes (PECs), isolated from higher plants, and whole photosynthetic organisms (algae) allows a wide range of toxic inhibitors to be detected within 10-15 min. The detection thresholds obtained for individual toxic chemicals indicate that algae are less sensitive to metal cations than PECs, because of the algal cell wall being ion selective. However, other toxic chemicals, such as phenolic compounds and nitrogen ammonia, acting on the last constituents of the photosynthetic enzyme complex that are degraded during the PEC extraction process, are more easily detected with algae after just 10 min of exposure. The combination of PECs and algae is not only useful for rapid toxicity screening, but yields results that are as sensitive as those of standard bioassays. Toxicity data generated with mining industry effluents demonstrate that PECs routinely prove to be as sensitive as daphnia, while algal sensitivity is comparable to that of the standard trout bioassay. An important feature of LuminoTox and algal photosynthetic system testing, however, resides in the production of their rapid and sensitive responses (10-15 min) in comparison with those of the more traditional tests (48-96 h for daphnia and trout, respectively).

Modelling and simulation of an infant's whole body plethysmograph.

In this paper, we describe a computational model dedicated to building an apnoea monitoring system for newborn babies. The proposed model is based on whole body plethysmography, which involves non-invasive measurement of lung ventilation indirectly from the pressure deflections generated when a subject breathes inside a chamber of fixed volume (Bert in C R Soc Biol Paris 20:22-23, 1868). The computational model simulates thermal and environmental flow conditions occurring in the neonate chamber, especially steady state flow with heat transfer and carbon dioxide (CO2) transport during the exhalation phase. This permits the variance of all critical parameters and the analysis of their effects on the distributions of interest. The main objective is to study thermal and air quality comfort conditions under which infants can be monitored for long-term periods. The method deploys computational fluid dynamics techniques and parametric modelling which, by allowing input parameters to be modulated, represent a more efficient and flexible analytical tool than previous experimental techniques. Simulation data reveal that the largest flow rates occur in areas near the openings with slight formation of air recirculation zones; temperature distribution shows signs of stratification, with higher temperatures than the supplied air, CO2 distribution presents acceptable air quality level and predicted mean vote index affords a relatively acceptable thermal comfort level. This analytical approach can be considered as innovative, and can find a new application in clinical infant apnoea monitoring in a way that allows determination of the optimal location for placing a sensor to detect respiration activity without any contact with the infant's body, and without any risk, in contrast to available whole body plethysmography techniques previously tested in infants (Fleming et al. in J Appl Physiol 55:1924-1931, 1983).

Sexual dimorphism of human ribs.

The volume of the rib cage is about 10% smaller in females than in males having the same height although the reason for this is presently unclear. The cranio-caudal inclination of ribs is greater in females than males but the length of ribs has not previously been compared between the sexes. In 23 males and 23 females studied at necropsy, body length, the length of the upper and lower limbs and the length of the thoracic spine were all smaller in females but the ratios of upper and lower limb lengths to body length and of thoracic spine length to body length were not different. By contrast, the lengths of the third, sixth and ninth ribs were not significantly different between males and females and the ratios of rib length to body length were all significantly greater in females. We conclude that in females the ribs grow longer in relation to the axial skeleton than in males.

Reversibility of airflow obstruction by hypoglossus nerve stimulation in anesthetized rabbits.

RATIONALE: Anesthesia-induced uncoupling of upper airway dilating and inspiratory pump muscles activation may cause inspiratory flow limitation, thereby mimicking obstructive sleep apnea/hypopnea. OBJECTIVES: Determine whether inspiratory flow limitation occurs in spontaneously breathing anesthetized rabbits and whether this can be reversed by direct hypoglossal nerve stimulation and by the application of continuous positive airway pressure. METHODS: Ten New Zealand White rabbits were anesthetized, instrumented, and studied supine while breathing spontaneously at ambient pressure or during the application of positive or negative airway pressure. Under each of these conditions, the effect of unilateral or bilateral hypoglossal nerve stimulation was investigated. MEASUREMENTS: Inspiratory flow and tidal volume were measured together with esophageal pressure and the electromyographic activity of diaphragm, alae nasi, and genioglossus muscles. MAIN RESULTS: Anesthesia caused a marked increase in inspiratory resistance, snoring, and in eight rabbits, inspiratory flow limitation. Hypoglossus nerve stimulation was as effective as continuous positive airway pressure in reversing inspiratory flow limitation and snoring. Its effectiveness increased progressively as airway opening pressure was lowered, reached a maximum at -5 cm H2O, but declined markedly at lower pressures. With negative airway opening pressure, airway collapse eventually occurred during inspiration that could be prevented by hypoglossus nerve stimulation. The recruitment characteristics of hypoglossus nerve fibers was steep, and significant upper airway dilating effects already obtained with stimulus intensities 36 to 60% of maximum. CONCLUSION: This study supports hypoglossus nerve stimulation as a treatment option for obstructive sleep apnea.

Sex differences in thoracic dimensions and configuration.

The volume of adult female lungs is typically 10-12% smaller than that of males who have the same height and age. In this study, we investigated how this volume difference is distributed between the rib cage and the diaphragm abdomen compartments. Internal rib cage dimensions, diaphragm position relative to spine, and diaphragm length were compared in 21 normal male and 19 normal female subjects at three different lung volumes using anterior-posterior and lateral chest radiographs. At all lung volumes examined, females had smaller radial rib cage dimensions in relationship to height than males, a greater inclination of ribs, a comparable diaphragm dome position relative to the spine, and a shorter diaphragm length. Female subjects exhibited a greater inspiratory rib cage muscle contribution during resting breathing than males, presumably reflecting an improved mechanical advantage conferred to these muscles by the greater inclination of ribs. Because of a greater inclination of ribs, female rib cages could accommodate a greater volume expansion. The results suggest a disproportionate growth of the rib cage in females relative to the lung, which would be well suited to accommodate large abdominal volume displacements as in pregnancy.

Effects of abdominal distension on breathing pattern and respiratory mechanics in rabbits.

The effects of acute abdominal distension (AD) on the electromechanical efficiency (Eff) of the inspiratory muscles were investigated in anesthetized rabbits by recording the electrical activity (A), pressure (P) exerted by the diaphragm (di) and parasternal intercostal muscles (ic), and lung volume changes when an abdominal balloon was inflated to various degrees. Eff,ic increased with increasing AD both in supine and upright postures. In upright rabbits Eff,di increased for intermediate but decreased at higher levels of AD, whilst it decreased at all levels of AD in supine rabbits. Tidal volume (VT) response followed that of Eff,di. Tonic Aic and Adi and inspiratory prolongation were elicited by AD. The effects of these neural mechanisms, acting to limit end-expiratory lung volume and VT changes, were however small since vagotomy prevented tonic Adi and inspiratory prolongation and reduced tonic Aic, but changed lung volume responses to AD only little. Hence, reduced respiratory system compliance and changes in inspiratory muscle electromechanical efficiency dominate lung volume responses to acute AD.

Effects of emphysema and lung volume reduction surgery on transdiaphragmatic pressure and diaphragm length.

STUDY OBJECTIVES: To determine the effect of emphysema and lung volume reduction surgery (LVRS) on diaphragm length (Ldi) and its capacity to generate transdiaphragmatic pressure (Pdi). DESIGN: Prospective clinical trial with a parallel group design. SETTING: Laboratory investigations in normal volunteers recruited by advertisement and in emphysema outpatients being evaluated for elective LVRS. STUDY POPULATION: Thirteen normal subjects and 13 emphysema patients matched for age and sex. Six emphysema patients underwent LVRS. MEASUREMENTS: Ldi and maximal Pdi during static inspiratory efforts (PdiMax) were measured at three different lung volumes (LVs). Pdi during maximal bilateral phrenic nerve twitch stimulation (PdiTw) was measured at functional residual capacity (FRC). All measurements were repeated at 3, 6, and 12 months postoperatively. RESULTS: Ldi, PdiMax, and PdiTw were lower in emphysema patients than in normal subjects at their respective LVs. PdiMax and PdiTw at FRC returned within the normal range after LVRS in emphysema patients. The relationships between PdiMax and LV or Ldi were shifted respectively to higher LV and shorter Ldi in emphysema patients relative to normal subjects, both before and after LVRS. LVRS effected craniad displacement of the diaphragm but no change in rib cage dimensions. Improvements in dyspnea and quality of life after LVRS correlated with changes in LV and Ldi but not with changes in airway caliber. CONCLUSION: Adaptive mechanisms, consistent with sarcomere deletion, tend to restore diaphragm strength in emphysema patients at FRC, which are fully expressed after LVRS. Lung remodeling by LVRS may alter pleural surface pressure distribution, causing a sustained change in chest wall shape.