What is the impact of a fast-track pathway on length of stay for adult patients with a hip fracture? A systematic review.

INTRODUCTION: In orthopaedic surgery, hip fracture patients represent one of the largest cohorts. Hip fracture is a serious injury commonly occurring in frail and elderly patients. Fast-track admission pathways aim to streamline patients through accident and emergency departments, resulting in shorter wait times and less negative patient outcomes. AIM: To examine the impact of a fast-track pathway on length of stay for adults admitted to an acute hospital with a hip fracture. METHODS: CINAHL Plus with Full text (via EBSCO host), MEDLINE, Cochrane Library, and Embase database searches were carried out in January 2021, to find all relevant literature for this review, as well as through searching additional sources. Eligible studies were quantitative primary research, focusing on the use of fast-track admission pathway care versus usual care, for adults with a hip fracture. The assessment of study suitability, data extraction, and critical appraisal was carried out by two independent authors. A narrative analysis of the data was conducted, and data were meta-analysed using RevMan where possible. Quality appraisal of the included studies was undertaken using the EBL checklist. RESULTS: Seven studies reporting data on 5723 patients were included. Length of stay, time to surgery, and mortality did not differ significantly between the fast-track care, and usual care. One study reported on delirium and found statistically significantly fewer encounters of delirium in fast-track care versus usual care. Four of the seven studies satisfied rigorous quality appraisal (> 75%) using the EBL. CONCLUSION: The fast-track pathway avoided unnecessary delays in emergency departments due to faster X-rays, direct admission to orthopaedic wards, and reduced delirium rates. However, results were unable to show the impact of fast-track on length of stay, time to surgery, and mortality.

Influences and Impact of Anxiety and Depression in the Setting of Inflammatory Bowel Disease.

Background: Individuals with inflammatory bowel disease (IBD) are at increased risk of developing anxiety or depression (A&D). Crohn's disease (CD) and ulcerative colitis (UC) with comorbid A&D are both more challenging to manage. IBD providers need to better understand the causes and impact of A&D in order to improve care for IBD patients. We sought to identify clinical factors that influence development of A&D and healthcare utilization in IBD. Methods: This is a retrospective analysis using an IBD natural history registry from a single tertiary care referral center. Presence of A&D was determined based upon responses to the Hospital Anxiety and Depression Scale. Demographic and clinical factors were abstracted to evaluate for significant associations. Results: Four hundred thirty-two IBD patients (132 UC, 256 CD, and 44 indeterminate colitis) were included in this study. One hundred ninety-two (44.4%) had anxiety or depression or both, and most were female (59.4%, P < 0.05). History of surgery (P < 0.05), female gender (P < 0.05), smoking (P < 0.05), and extra-intestinal manifestations (P < 0.01) were each independently predictive of A&D. Inflammatory bowel disease patients with A&D more often underwent imaging studies (53.6% vs 36.7%, P < 0.05), visited the ED (30.7% vs 20.8%, P < 0.05), or were hospitalized (31.7% vs 21.7%, P < 0.05). They were also more frequently prescribed corticosteroids (50.5% vs 36.7%, P < 0.01) and biologic medications (62.5% vs 51.3%, P < 0.05). Finally, they were more likely to have had at least 1 "no-show" (29.2% vs 16.7%, P < 0.01) and had a higher mean number of "no-shows" (0.69 +/- 0.1 vs 0.30 +/- 0.1, P < 0.01) over the study period. Discussion: Anxiety and depression are common in the setting of IBD and are strongly associated with surgical history, disease complications (including extra-intestinal manifestations), smoking, and female gender. Inflammatory bowel disease patients with A&D are also more likely to require therapy and to utilize healthcare resources. This study refines our understanding of A&D development and its impact in IBD and provides additional considerations for management in this setting.

Mechanistic link between diesel exhaust particles and respiratory reflexes.

BACKGROUND: Diesel exhaust particles (DEPs) are a major component of particulate matter in Europe's largest cities, and epidemiologic evidence links exposure with respiratory symptoms and asthma exacerbations. Respiratory reflexes are responsible for symptoms and are regulated by vagal afferent nerves, which innervate the airway. It is not known how DEP exposure activates airway afferents to elicit symptoms, such as cough and bronchospasm. OBJECTIVE: We sought to identify the mechanisms involved in activation of airway sensory afferents by DEPs. METHODS: In this study we use in vitro and in vivo electrophysiologic techniques, including a unique model that assesses depolarization (a marker of sensory nerve activation) of human vagus. RESULTS: We demonstrate a direct interaction between DEP and airway C-fiber afferents. In anesthetized guinea pigs intratracheal administration of DEPs activated airway C-fibers. The organic extract (DEP-OE) and not the cleaned particles evoked depolarization of guinea pig and human vagus, and this was inhibited by a transient receptor potential ankyrin-1 antagonist and the antioxidant N-acetyl cysteine. Polycyclic aromatic hydrocarbons, major constituents of DEPs, were implicated in this process through activation of the aryl hydrocarbon receptor and subsequent mitochondrial reactive oxygen species production, which is known to activate transient receptor potential ankyrin-1 on nociceptive C-fibers. CONCLUSIONS: This study provides the first mechanistic insights into how exposure to urban air pollution leads to activation of guinea pig and human sensory nerves, which are responsible for respiratory symptoms. Mechanistic information will enable the development of appropriate therapeutic interventions and mitigation strategies for those susceptible subjects who are most at risk.

Transient receptor potential cation channel, subfamily V, member 4 and airway sensory afferent activation: Role of adenosine triphosphate.

BACKGROUND: Sensory nerves innervating the airways play an important role in regulating various cardiopulmonary functions, maintaining homeostasis under healthy conditions and contributing to pathophysiology in disease states. Hypo-osmotic solutions elicit sensory reflexes, including cough, and are a potent stimulus for airway narrowing in asthmatic patients, but the mechanisms involved are not known. Transient receptor potential cation channel, subfamily V, member 4 (TRPV4) is widely expressed in the respiratory tract, but its role as a peripheral nociceptor has not been explored. OBJECTIVE: We hypothesized that TRPV4 is expressed on airway afferents and is a key osmosensor initiating reflex events in the lung. METHODS: We used guinea pig primary cells, tissue bioassay, in vivo electrophysiology, and a guinea pig conscious cough model to investigate a role for TRPV4 in mediating sensory nerve activation in vagal afferents and the possible downstream signaling mechanisms. Human vagus nerve was used to confirm key observations in animal tissues. RESULTS: Here we show TRPV4-induced activation of guinea pig airway-specific primary nodose ganglion cells. TRPV4 ligands and hypo-osmotic solutions caused depolarization of murine, guinea pig, and human vagus and firing of Aδ-fibers (not C-fibers), which was inhibited by TRPV4 and P2X3 receptor antagonists. Both antagonists blocked TRPV4-induced cough. CONCLUSION: This study identifies the TRPV4-ATP-P2X3 interaction as a key osmosensing pathway involved in airway sensory nerve reflexes. The absence of TRPV4-ATP-mediated effects on C-fibers indicates a distinct neurobiology for this ion channel and implicates TRPV4 as a novel therapeutic target for neuronal hyperresponsiveness in the airways and symptoms, such as cough.

Neurophenotypes in Airway Diseases. Insights from Translational Cough Studies.

RATIONALE: Most airway diseases, including chronic obstructive pulmonary disease (COPD), are associated with excessive coughing. The extent to which this may be a consequence of increased activation of vagal afferents by pathology in the airways (e.g., inflammatory mediators, excessive mucus) or an altered neuronal phenotype is unknown. Understanding whether respiratory diseases are associated with dysfunction of airway sensory nerves has the potential to identify novel therapeutic targets. OBJECTIVES: To assess the changes in cough responses to a range of inhaled irritants in COPD and model these in animals to investigate the underlying mechanisms. METHODS: Cough responses to inhaled stimuli in patients with COPD, healthy smokers, refractory chronic cough, asthma, and healthy volunteers were assessed and compared with vagus/airway nerve and cough responses in a cigarette smoke (CS) exposure guinea pig model. MEASUREMENTS AND MAIN RESULTS: Patients with COPD had heightened cough responses to capsaicin but reduced responses to prostaglandin E2 compared with healthy volunteers. Furthermore, the different patient groups all exhibited different patterns of modulation of cough responses. Consistent with these findings, capsaicin caused a greater number of coughs in CS-exposed guinea pigs than in control animals; similar increased responses were observed in ex vivo vagus nerve and neuron cell bodies in the vagal ganglia. However, responses to prostaglandin E2 were decreased by CS exposure. CONCLUSIONS: CS exposure is capable of inducing responses consistent with phenotypic switching in airway sensory nerves comparable with the cough responses observed in patients with COPD. Moreover, the differing profiles of cough responses support the concept of disease-specific neurophenotypes in airway disease. Clinical trial registered with www.clinicaltrials.gov (NCT 01297790).

Anti-inflammatory effects of PGE2 in the lung: role of the EP4 receptor subtype.

BACKGROUND: Asthma and chronic obstructive pulmonary disease (COPD) are chronic inflammatory diseases of the airway. Current treatment options (long acting ß-adrenoceptor agonists and glucocorticosteroids) are not optimal as they are only effective in certain patient groups and safety concerns exist regarding both compound classes. Therefore, novel bronchodilator and anti-inflammatory strategies are being pursued. Prostaglandin E2 (PGE2) is an arachidonic acid-derived eicosanoid produced by the lung which acts on four different G-protein coupled receptors (EP1-4) to cause an array of beneficial and deleterious effects. The aim of this study was to identify the EP receptor mediating the anti-inflammatory actions of PGE2 in the lung using a range of cell-based assays and in vivo models. METHODS AND RESULTS: It was demonstrated in three distinct model systems (innate stimulus, lipopolysaccharide (LPS); allergic response, ovalbumin (OVA); inhaled pollutant, cigarette smoke) that mice missing functional EP4 (Ptger4(-/-)) receptors had higher levels of airway inflammation, suggesting that endogenous PGE2 was suppressing inflammation via EP4 receptor activation. Cell-based assay systems (murine and human monocytes/alveolar macrophages) demonstrated that PGE2 inhibited cytokine release from LPS-stimulated cells and that this was mimicked by an EP4 (but not EP1-3) receptor agonist and inhibited by an EP4 receptor antagonist. The anti-inflammatory effect occurred at the transcriptional level and was via the adenylyl cyclase/cAMP/ cAMP-dependent protein kinase (PKA) axis. CONCLUSION: This study demonstrates that EP4 receptor activation is responsible for the anti-inflammatory activity of PGE2 in a range of disease relevant models and, as such, could represent a novel therapeutic target for chronic airway inflammatory conditions.

Role of the inflammasome-caspase1/11-IL-1/18 axis in cigarette smoke driven airway inflammation: an insight into the pathogenesis of COPD.

BACKGROUND: Chronic Obstructive Pulmonary Disease (COPD) is an inflammatory airway disease often associated with cigarette smoke (CS) exposure. The disease is increasing in global prevalence and there is no effective therapy. A major step forward would be to understand the disease pathogenesis. The ATP-P2X7 pathway plays a dominant role in murine models of CS induced airway inflammation, and markers of activation of this axis are upregulated in patients with COPD. This strongly suggests that the axis could be important in the pathogenesis of COPD. The aim of this study was to perform a detailed characterisation of the signalling pathway components involved in the CS-driven, P2X7 dependent airway inflammation. METHODS: We used a murine model system, bioassays and a range of genetically modified mice to better understand this complex signalling pathway. RESULTS: The inflammasome-associated proteins NALP3 and ASC, but not IPAF and AIM2, are required for CS-induced IL-1ß/IL-18 release, but not IL-1α. This was associated with a partial decrease in lung tissue caspase 1 activity and BALF neutrophilia. Mice missing caspase 1/11 or caspase 11 had markedly attenuated levels of all three cytokines and neutrophilia. Finally the mechanism by which these inflammatory proteins are involved in the CS-induced neutrophilia appeared to be via the induction of proteins involved in neutrophil transmigration e.g. E-Selectin. CONCLUSION: This data indicates a key role for the P2X7-NALP3/ASC-caspase1/11-IL-1ß/IL-18 axis in CS induced airway inflammation, highlighting this pathway as a possible therapeutic target for the treatment of COPD.

Role of transient receptor potential and pannexin channels in cigarette smoke-triggered ATP release in the lung.

BACKGROUND: COPD is an inflammatory disease usually associated with cigarette smoking (CS) with an increasing global prevalence and no effective medication. Extracellular ATP is increased in the COPD affected lung and may play a key role in driving CS-induced airway inflammation, but the mechanism involved in ATP release has eluded researchers. Recently, the transient receptor potential (TRP) and pannexin-1 channels have been suggested to play a role in other experimental paradigms. Thus, the aim of this work is to investigate if these channels are involved in CS-induced ATP release in the lung. METHODS: Primary human cells were exposed to CS and extracellular ATP levels measured. Mice were exposed to mainstream CS and airway inflammation assessed. TRPV1/4 mRNA expression was assessed in human lung parenchyma. RESULTS: CS exposure caused a dose-related increase in ATP from primary airway bronchial epithelial cells. This was attenuated by blockers of TRPV1, TRPV4 and pannexin-1 channels. Parallel data was obtained using murine acute CS-driven model systems. Finally, TRPV1/4 mRNA expression was increased in lung tissue samples from patients with COPD. CONCLUSIONS: Extracellular ATP is increased in the COPD affected lung and may play a key role in driving disease pathophysiology. These experiments uncover a novel mechanism which may be responsible for CS-induced ATP release. These findings highlight novel targets that could lead to the development of medicine to treat this devastating disease.

Theophylline inhibits the cough reflex through a novel mechanism of action.

BACKGROUND: Theophylline has been used in the treatment of asthma and chronic obstructive pulmonary disease for more than 80 years. In addition to bronchodilator and anti-inflammatory activity, clinical studies have suggested that theophylline acts as an antitussive agent. Cough is the most frequent reason for consultation with a family doctor, and treatment options are limited. Determining how theophylline inhibits cough might lead to the development of optimized compounds. OBJECTIVE: We sought to investigate the inhibitory activity of theophylline on vagal sensory nerve activity and the cough reflex. METHODS: Using a range of techniques, we investigated the effect of theophylline on human and guinea pig vagal sensory nerve activity in vitro and on the cough reflex in guinea pig challenge models. RESULTS: Theophylline was antitussive in a guinea pig model, inhibited activation of single C-fiber afferents in vivo and depolarization of human and guinea pig vagus in vitro, and inhibited calcium influx in airway-specific neurons in vitro. A sequence of pharmacological studies on the isolated vagus and patch clamp and single-channel inside-out experiments showed that the effect of theophylline was due to an increase in the open probability of calcium-activated potassium channels. Finally, we demonstrated the antitussive activity of theophylline in a cigarette smoke exposure model that exhibited enhanced tussive responses to capsaicin. CONCLUSION: Theophylline inhibits capsaicin-induced cough under both normal and "disease" conditions by decreasing the excitability of sensory nerves through activation of small- and intermediate-conductance calcium-activated potassium channels. These findings could lead to the development of optimized antitussive compounds with a reduced side effect potential.

TRPA1 is activated by direct addition of cysteine residues to the N-hydroxysuccinyl esters of acrylic and cinnamic acids.

The nociceptor TRPA1 is thought to be activated through covalent modification of specific cysteine residues on the N terminal of the channel. The precise mechanism of covalent modification with unsaturated carbonyl-containing compounds is unclear, therefore by examining a range of compounds which can undergo both conjugate and/or direct addition reactions we sought to further elucidate the mechanism(s) whereby TRPA1 can be activated by covalent modification. Calcium signalling was used to determine the mechanism of activation of TRPA1 expressed in HEK293 cells with a series of related compounds which were capable of either direct and/or conjugate addition processes. These results were confirmed using physiological recordings with isolated vagus nerve preparations. We found negligible channel activation with chemicals which could only react with cysteine residues via conjugate addition such as acrylamide, acrylic acid, and cinnamic acid. Compounds able to react via either conjugate or direct addition, such as acrolein, methyl vinyl ketone, mesityl oxide, acrylic acid NHS ester, cinnamaldehyde and cinnamic acid NHS ester, activated TRPA1 in a concentration dependent manner as did compounds only capable of direct addition, namely propionic acid NHS ester and hydrocinnamic acid NHS ester. These compounds failed to activate TRPV1 expressed in HEK293 cells or mock transfected HEK293 cells. For molecules capable of direct or conjugate additions, the results suggest for the first time that TRPA1 may be activated preferentially by direct addition of the thiol group of TRPA1 cysteines to the agonist carbonyl carbon of α,ß-unsaturated carbonyl-containing compounds.

TRPA1 agonists evoke coughing in guinea pig and human volunteers.

RATIONALE: Cough is the most frequent reason for consultation with a family doctor, or with a general or respiratory physician. Treatment options are limited and one meta-analysis concluded that over-the-counter remedies are ineffective. There is also increasing concern about their use in children. Environmental irritants such as air pollution and cigarette smoke are thought to evoke cough by stimulating airway sensory nerves; however, how this occurs is not fully understood. OBJECTIVES: We hypothesized that the TRPA1 (transient receptor potential cation channel, subfamily A, member 1) receptor may have a role as a novel target for tussive agents given that many potential irritants have been shown to activate this channel. METHODS: We investigated the effect of TRPA1 ligands on vagal sensory nerve activity in vitro and in guinea pig and human tussive challenge models. MEASUREMENTS AND MAIN RESULTS: We demonstrated that TRPA1 agonists such as acrolein activate cloned human TRPA1 channels in HEK293 cells and also vagal sensory nerves in murine, guinea pig, and human tissues. A role for TRPA1 was confirmed, using specific inhibitors and tissue from Trpa1(-/-) gene-deleted animals. Finally, TRPA1 ligands evoked reproducible tussive responses in both a guinea pig model and normal volunteers. CONCLUSIONS: This study identifies the TRPA1 receptor as a promiscuous receptor, activated by a wide range of stimuli, making it a perfect target for triggering cough and as such one of the most promising targets currently identified for the development of antitussive drugs.

Allergen sensitivity and asthma severity at an inner city asthma center.

The objective of this study was to examine the relationship of allergen sensitivity to asthma symptoms among inner-city asthmatics seen at our Brooklyn, NY, asthma center. We hypothesized that asthma severity would increase for adults and children with increased cockroach and dust mite allergen sensitivity. Data were gathered from retrospective chart review for all patients who were treated at the center with a diagnosis of asthma and had undergone skin-prick testing (SPT) for allergen sensitivity during 1998 (pediatric, n = 79; adult, n = 29). Asthma severity (determined by National Heart, Lung and Blood Institute [NHLBI] asthma severity class) was examined in relation to allergen sensitivity. Allergen sensitivity was measured by percent positive to skin-prick testing as well as by relative mean diameter of skin prick test wheals. For adults, mite sensitivity prevalence was 61% and cockroach sensitivity prevalence was 41%. For children, mite sensitivity prevalence was 49%; cockroach sensitivity prevalence was 42%. For adults, asthma severity correlated significantly with sensitivity to Cladosporium, tree, and grass as measured by percent positive skin tests and by increasing mean diameter of skin test wheals. There was a significant correlation with severity for adult dust mite sensitivity only as measured by increasing mean wheal diameter. Ragweed sensitivity showed a significant correlation with severity only as measured by percent positive skin tests. There was a significant positive association for adults between increasing asthma severity and total number of allergen sensitivities per subject. There was no significant correlation for children between asthma severity and total number of allergen sensitivities per subject. Among children, no specific allergen sensitization showed a significant positive association with asthma severity. By both measures of allergen sensitization, there was a significant negative association for children between Cladosporium and asthma severity. Among our inner-city asthmatic population significant correlation between mite sensitivity and asthma severity was found only in adults. No significant association was seen with cockroach. However, outdoor allergen sensitivity (Cladosporidium, tree, ragweed, and grass) significantly correlated with asthma for adults in this inner city population.