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Seminars in Respiratory and Critical... Oct 2023While static mechanical forces govern resting lung volumes, dynamic forces determine tidal breathing, airflow, and changes in airflow and lung volume during normal and...
While static mechanical forces govern resting lung volumes, dynamic forces determine tidal breathing, airflow, and changes in airflow and lung volume during normal and abnormal breathing. This section will examine the mechanisms, measurement methodology, and interpretation of the dynamic changes in airflow and lung volume that occur in health and disease. We will first examine how the total work of breathing can be described by the parameters of the equation of motion, which determine the pressure required to move air into and out of the lung. This will include a detailed description of airflow characteristics and airway resistance. Next, we will review the changes in pressure and flow that determine maximal forced inspiration and expiration, which result in the maximal flow-volume loop and the clinically important forced expired volume in 1 second. We will also assess the mechanisms and interpretation of bronchodilator responsiveness, dynamic hyperinflation, and airways hyperresponsiveness.
Topics: Humans; Lung; Bronchodilator Agents
PubMed: 37429331
DOI: 10.1055/s-0043-1770058 -
The American Journal of Gastroenterology Aug 2021Chronic abdominal pain is a common gastrointestinal (GI) symptom that characterizes many functional GI disorders/disorders of gut-brain interaction, including irritable... (Review)
Review
Chronic abdominal pain is a common gastrointestinal (GI) symptom that characterizes many functional GI disorders/disorders of gut-brain interaction, including irritable bowel syndrome, functional dyspepsia, and centrally mediated abdominal pain syndrome. The symptoms of abdominal pain in these highly prevalent disorders are often treated with antispasmodic agents. Antispasmodic treatment includes a broad range of therapeutic classes with different mechanisms of action, including anticholinergic/antimuscarinic agents (inhibition of GI smooth muscle contraction), calcium channel inhibitors (inhibition of calcium transport into GI smooth muscle), and direct smooth muscle relaxants (inhibition of sodium and calcium transport). The aim of this review article was to examine the efficacy and safety of antispasmodics available in North America (e.g., alverine, dicyclomine, hyoscine, hyoscyamine, mebeverine, otilonium, pinaverium, and trimebutine) for the treatment of chronic abdominal pain in patients with common disorders of gut-brain interaction. For the agents examined, comparisons of studies are limited by inconsistencies in treatment dosing and duration, patient profiles, and diagnostic criteria employed. Furthermore, variability in study end points limits comparisons. Risk of selection, performance, detection, attrition, and reporting bias also differed among studies, and in many cases, risks were considered "unclear." The antispasmodics evaluated in this review, which differ in geographic availability, were found to vary dramatically in efficacy and safety. Given these caveats, each agent should be considered on an individual basis, rather than prescribed based on information across the broad class of agents.
Topics: Abdominal Pain; Chronic Pain; Humans; North America; Parasympatholytics
PubMed: 33993133
DOI: 10.14309/ajg.0000000000001266 -
Health Technology Assessment... Oct 2016Nausea and vomiting in pregnancy (NVP) affects up to 85% of all women during pregnancy, but for the majority self-management suffices. For the remainder, symptoms are... (Review)
Review
BACKGROUND
Nausea and vomiting in pregnancy (NVP) affects up to 85% of all women during pregnancy, but for the majority self-management suffices. For the remainder, symptoms are more severe and the most severe form of NVP - hyperemesis gravidarum (HG) - affects 0.3-1.0% of pregnant women. There is no widely accepted point at which NVP becomes HG.
OBJECTIVES
This study aimed to determine the relative clinical effectiveness and cost-effectiveness of treatments for NVP and HG.
DATA SOURCES
MEDLINE, EMBASE, Cumulative Index to Nursing and Allied Health Literature, Cochrane Central Register of Controlled Trials, PsycINFO, Commonwealth Agricultural Bureaux (CAB) Abstracts, Latin American and Caribbean Health Sciences Literature, Allied and Complementary Medicine Database, British Nursing Index, Science Citation Index, Social Sciences Citation Index, Scopus, Conference Proceedings Index, NHS Economic Evaluation Database, Health Economic Evaluations Database, China National Knowledge Infrastructure, Cochrane Database of Systematic Reviews and Database of Abstracts of Reviews of Effects were searched from inception to September 2014. References from studies and literature reviews identified were also examined. was hand-searched, as were websites of relevant organisations. Costs came from NHS sources.
REVIEW METHODS
A systematic review of randomised and non-randomised controlled trials (RCTs) for effectiveness, and population-based case series for adverse events and fetal outcomes. Treatments: vitamins B6 and B12, ginger, acupressure/acupuncture, hypnotherapy, antiemetics, dopamine antagonists, 5-hydroxytryptamine receptor antagonists, intravenous (i.v.) fluids, corticosteroids, enteral and parenteral feeding or other novel treatment. Two reviewers extracted data and quality assessed studies. Results were narratively synthesised; planned meta-analysis was not possible due to heterogeneity and incomplete reporting. A simple economic evaluation considered the implied values of treatments.
RESULTS
Seventy-three studies (75 reports) met the inclusion criteria. For RCTs, 33 and 11 studies had a low and high risk of bias respectively. For the remainder ( = 20) it was unclear. The non-randomised studies ( = 9) were low quality. There were 33 separate comparators. The most common were acupressure versus placebo ( = 12); steroid versus usual treatment ( = 7); ginger versus placebo ( = 6); ginger versus vitamin B6 ( = 6); and vitamin B6 versus placebo ( = 4). There was evidence that ginger, antihistamines, metoclopramide (mild disease) and vitamin B6 (mild to severe disease) are better than placebo. Diclectin [Duchesnay Inc.; doxylamine succinate (10 mg) plus pyridoxine hydrochloride (10 mg) slow release tablet] is more effective than placebo and ondansetron is more effective at reducing nausea than pyridoxine plus doxylamine. Diclectin before symptoms of NVP begin for women at high risk of severe NVP recurrence reduces risk of moderate/severe NVP compared with taking Diclectin once symptoms begin. Promethazine is as, and ondansetron is more, effective than metoclopramide for severe NVP/HG. I.v. fluids help correct dehydration and improve symptoms. Dextrose saline may be more effective at reducing nausea than normal saline. Transdermal clonidine patches may be effective for severe HG. Enteral feeding is effective but extreme method treatment for very severe symptoms. Day case management for moderate/severe symptoms is feasible, acceptable and as effective as inpatient care. For all other interventions and comparisons, evidence is unclear. The economic analysis was limited by lack of effectiveness data, but comparison of costs between treatments highlights the implications of different choices.
LIMITATIONS
The main limitations were the quantity and quality of the data available.
CONCLUSION
There was evidence of some improvement in symptoms for some treatments, but these data may not be transferable across disease severities. Methodologically sound and larger trials of the main therapies considered within the UK NHS are needed.
STUDY REGISTRATION
This study is registered as PROSPERO CRD42013006642.
FUNDING
The National Institute for Health Research Health Technology Assessment programme.
Topics: Antiemetics; Clinical Trials as Topic; Complementary Therapies; Cost-Benefit Analysis; Female; Fluid Therapy; Humans; Hyperemesis Gravidarum; Nausea; Pregnancy
PubMed: 27731292
DOI: 10.3310/hta20740 -
Canadian Family Physician Medecin de... Jun 2022
Topics: Bronchiolitis, Viral; Bronchodilator Agents; Humans
PubMed: 35701205
DOI: 10.46747/cfp.6806429 -
British Medical Journal Feb 1968
Topics: Antiemetics; Gastrointestinal Motility; Humans; Radiography; Stomach
PubMed: 5639631
DOI: No ID Found -
Public Health Reports (Washington, D.C.... Oct 1960
Topics: Antiemetics; Fluorescent Antibody Technique
PubMed: 13695290
DOI: No ID Found -
Advances in Experimental Medicine and... 2019Several review articles have been published on the neurobehavioral actions of acetaldehyde and other ethanol metabolites as well as in major alcohol-related disorders... (Review)
Review
Several review articles have been published on the neurobehavioral actions of acetaldehyde and other ethanol metabolites as well as in major alcohol-related disorders such as cancer and liver and lung disease. However, very few reviews dealt with the role of alcohol metabolism in the adverse cardiac and autonomic effects of alcohol and their potential underlying mechanisms, particularly in vulnerable populations. In this chapter, following a brief overview of the dose-related favorable and adverse cardiovascular effects of alcohol, we discuss the role of ethanol metabolism in its adverse effects in the brainstem and heart. Notably, current knowledge dismisses a major role for acetaldehyde in the adverse autonomic and cardiac effects of alcohol because of its low tissue level in vivo. Contrary to these findings in men and male rodents, women and hypertensive individuals are more sensitive to the adverse cardiac effects of similar amounts of alcohol. To understand this discrepancy, we discuss the autonomic and cardiac effects of alcohol and its metabolite acetaldehyde in a model of hypertension, the spontaneously hypertensive rat (SHR) and female rats. We present evidence that enhanced catalase activity, which contributes to cardioprotection in hypertension (compensatory) and in the presence of estrogen (inherent), becomes detrimental due to catalase catalysis of alcohol metabolism to acetaldehyde. Noteworthy, studies in SHRs and in estrogen deprived or replete normotensive rats implicate acetaldehyde in triggering oxidative stress in autonomic nuclei and the heart via (i) the Akt/extracellular signal-regulated kinases (ERK)/nitric oxide synthase (NOS) cascade and (ii) estrogen receptor-alpha (ERα) mediation of the higher catalase activity, which generates higher ethanol-derived acetaldehyde in female heart. The latter is supported by the ability of ERα blockade or catalase inhibition to attenuate alcohol-evoked myocardial oxidative stress and dysfunction. More mechanistic studies are needed to further understand the mechanisms of this public health problem.
Topics: Acetaldehyde; Animals; Autonomic Agents; Ethanol; Female; Heart; Male; Myocardium; Oxidative Stress; Rats; Rats, Inbred SHR
PubMed: 31368095
DOI: 10.1007/978-981-13-6260-6_1 -
The European Respiratory Journal Nov 2017
Topics: Algorithms; Bronchodilator Agents; Humans; Pulmonary Disease, Chronic Obstructive
PubMed: 29097436
DOI: 10.1183/13993003.01733-2017 -
The Cochrane Database of Systematic... Jun 2013Prolonged labour can lead to increased maternal and neonatal mortality and morbidity due to increased risks of maternal exhaustion, postpartum haemorrhage and sepsis,... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Prolonged labour can lead to increased maternal and neonatal mortality and morbidity due to increased risks of maternal exhaustion, postpartum haemorrhage and sepsis, fetal distress and asphyxia and requires early detection and appropriate clinical response. The risks for complications of prolonged labour are much greater in poor resource settings. Active management of labour versus physiological, expectant management, has shown to decrease the occurrence of prolonged labour. Administering antispasmodics during labour could also lead to faster and more effective dilatation of the cervix. Interventions to shorten labour, such as antispasmodics, can be used as a preventative or a treatment strategy in order to decrease the incidence of prolonged labour. As the evidence to support this is still largely anecdotal around the world, there is a need to systematically review the available evidence to obtain a valid answer.
OBJECTIVES
To assess the effects of antispasmodics on labour in term pregnancies.
SEARCH METHODS
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (28 February 2013), the ProQuest dissertation and thesis database, the dissertation database of the University of Stellenbosch and Google Scholar (28 February 2013) and reference lists of articles. We also contacted pharmaceutical companies and experts in the field. We did not apply language restrictions.
SELECTION CRITERIA
Randomised controlled trials comparing antispasmodics with placebo or no medication in women with term pregnancies.
DATA COLLECTION AND ANALYSIS
Two review authors independently screened abstracts and selected studies for inclusion, assessed risk of bias and extracted data. Data were checked for accuracy. We contacted trial authors when data were missing.
MAIN RESULTS
Twenty-one trials (n = 3286) were included in the review. Seventeen trials (n = 2617) were included in the meta-analysis. Antispasmodics used included valethamate bromide, hyoscine butyl-bromide, drotaverine hydrochloride, rociverine and camylofin dihydrochloride. Most studies included antispasmodics as part of their package of active management of labour. Overall, the quality of studies was poor, as only four trials were assessed as low risk of bias. Thirteen trials (n = 1995) reported on the duration of first stage of labour, which was significantly reduced by an average of 74.34 minutes when antispasmodics were administered (mean difference (MD) -74.34 minutes; 95% confidence Interval (CI) -98.76 to -49.93). Seven studies (n = 797) reported on the total duration of labour, which was significantly reduced by an average of 85.51 minutes (MD -85.51 minutes; 95% CI -121.81 to -49.20). Six studies (n = 820) had data for the outcome: rate of cervical dilatation. Administration of antispasmodics significantly increased the rate of cervical dilatation by an average of 0.61 cm/hour (MD 0.61 cm/hour; 95% CI 0.34 to 0.88). Antispasmodics did not affect the duration of second and third stage of labour. The rate of normal vertex deliveries was not affected either. Only one study explored pain relief following administration of antispasmodics and no conclusions can be drawn on this outcome. There was significant heterogeneity for most outcomes and therefore, we undertook random-effects meta-analysis. Subgroup analysis was undertaken to explore heterogeneity, but remained largely unexplained. Maternal and neonatal adverse events were reported inconsistently. The main maternal adverse event reported was tachycardia. No serious neonatal adverse events were reported.
AUTHORS' CONCLUSIONS
There is low quality evidence that antispasmodics reduce the duration of first stage of labour and increase the cervical dilatation rate. There is very low quality evidence that antispasmodics reduce the total duration of labour. There is moderate quality evidence that antispasmodics do not affect the rate of normal vertex deliveries. There is insufficient evidence to make any conclusions regarding the safety of these drugs for both mother and baby. Large, rigorous randomised controlled trials are needed to evaluate the effect of antispasmodics on prolonged labour and to evaluate their effect on labour in a context of expectant management of labour.
Topics: Female; Humans; Labor Stage, First; Obstetric Labor Complications; Parasympatholytics; Pregnancy; Randomized Controlled Trials as Topic; Tachycardia
PubMed: 23737030
DOI: 10.1002/14651858.CD009243.pub3 -
Pharmacological Reviews Jan 2017Primary neurodegenerative autonomic disorders are characterized clinically by loss of autonomic regulation of blood pressure. The clinical picture is dominated by... (Review)
Review
Primary neurodegenerative autonomic disorders are characterized clinically by loss of autonomic regulation of blood pressure. The clinical picture is dominated by orthostatic hypotension, but supine hypertension is also a significant problem. Autonomic failure can result from impairment of central autonomic pathways (multiple system atrophy) or neurodegeneration of peripheral postganglionic autonomic fibers (pure autonomic failure, Parkinson's disease). Pharmacologic probes such as the ganglionic blocker trimethaphan can help us in the understanding of the underlying pathophysiology and diagnosis of these disorders. Conversely, understanding the pathophysiology is crucial in the development of effective pharmacotherapy for these patients. Autonomic failure patients provide us with an unfortunate but unique research model characterized by loss of baroreflex buffering. This greatly magnifies the effect of stimuli that would not be apparent in normal subjects. An example of this is the discovery of the osmopressor reflex: ingestion of water increases blood pressure by 30-40 mm Hg in autonomic failure patients. Animal studies indicate that the trigger of this reflex is related to hypo-osmolality in the portal circulation involving transient receptor potential vanilloid 4 receptors. Studies in autonomic failure patients have also revealed that angiotensin II can be generated through noncanonical pathways independent of plasma renin activity to contribute to hypertension. Similarly, the mineralocorticoid receptor antagonist eplerenone produces acute hypotensive effects, highlighting the presence of non-nuclear mineralocorticoid receptor pathways. These are examples of careful clinical research that integrates pathophysiology and pharmacology to advance our knowledge of human disease.
Topics: Animals; Autonomic Agents; Autonomic Nervous System; Autonomic Nervous System Diseases; Baroreflex; Blood Pressure; Cardiovascular Agents; Cardiovascular System; Ganglionic Blockers; Humans; Hypertension; Hypotension; Neurotransmitter Agents; Nitric Oxide; Renin-Angiotensin System; Supine Position; Sympathomimetics; Vasoconstrictor Agents
PubMed: 28011746
DOI: 10.1124/pr.115.012161