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Circulation Mar 2007More than 140 million people worldwide live >2500 m above sea level. Of them, 80 million live in Asia, and 35 million live in the Andean mountains. This latter region... (Review)
Review
More than 140 million people worldwide live >2500 m above sea level. Of them, 80 million live in Asia, and 35 million live in the Andean mountains. This latter region has its major population density living above 3500 m. The primary objective of the present study is to review the physiology, pathology, pathogenesis, and clinical features of the heart and pulmonary circulation in healthy highlanders and patients with chronic mountain sickness. A systematic review of worldwide literature was undertaken, beginning with the pioneering work done in the Andes several decades ago. Original articles were analyzed in most cases and English abstracts or translations of articles written in Chinese were reviewed. Pulmonary hypertension in healthy highlanders is related to a delayed postnatal remodeling of the distal pulmonary arterial branches. The magnitude of pulmonary hypertension increases with the altitude level and the degree of exercise. There is reversal of pulmonary hypertension after prolonged residence at sea level. Chronic mountain sickness develops when the capacity for altitude adaptation is lost. These patients have moderate to severe pulmonary hypertension with accentuated hypoxemia and exaggerated polycythemia. The clinical picture of chronic mountain sickness differs from subacute mountain sickness and resembles other chronic altitude diseases described in China and Kyrgyzstan. The heart and pulmonary circulation in healthy highlanders have distinct features in comparison with residents at sea level. Chronic mountain sickness is a public health problem in the Andean mountains and other mountainous regions around the world. Therefore, dissemination of preventive and therapeutic measures is essential.
Topics: Adaptation, Physiological; Adolescent; Adult; Aged; Aged, 80 and over; Altitude; Altitude Sickness; Animals; Cardiac Catheterization; Cardiac Output; Cattle; Cattle Diseases; Child; Child, Preschool; China; Chronic Disease; Diagnosis, Differential; Exercise; Female; Heart Ventricles; Humans; Hypertension, Pulmonary; Hypertrophy, Right Ventricular; Hypoxia; Infant; Infant, Newborn; Latin America; Male; Middle Aged; Muscle, Smooth, Vascular; Polycythemia; Pulmonary Artery; Pulmonary Circulation; Pulmonary Heart Disease; Vasodilator Agents; Ventricular Function
PubMed: 17339571
DOI: 10.1161/CIRCULATIONAHA.106.624544 -
Pediatrics Mar 2017Pulmonary hypertension (PH) is a syndrome that is of growing concern to pediatricians worldwide. Recent data led to concerns about the safety of phosphodiesterase type 5... (Review)
Review
Pulmonary hypertension (PH) is a syndrome that is of growing concern to pediatricians worldwide. Recent data led to concerns about the safety of phosphodiesterase type 5 (PDE5) inhibitors in children and a US Food and Drug Administration safety advisory. Our objective is to provide insight into therapies for PH in children and to systematically review the comparative effectiveness and safety of PDE5 inhibitors in the management of pediatric patients with PH. We searched the following databases through February 2015: Medline, Embase, SCOPUS, and the Cochrane Central Register of Controlled Trials. We included studies that examined PDE5 inhibitor use in children with PH. Allowed comparators were either no medication or other classes of medication for management of PH. Study inclusion was via a 2-stage process with 2 reviewers and a predesigned form. Of 1270 papers identified by the literature search, 21 were included: 8 randomized controlled trials and 13 observational studies (9 retrospective, 4 prospective). There is strong evidence that PDE5 inhibitor use improves echocardiography measurements, cardiac catheterization parameters, and oxygenation compared with baseline or placebo in pediatric patients with PH. Evidence suggests that low- and moderate-dose sildenafil are safe regimens for children. There are a relatively small number of randomized controlled trials that address use of PDE5 inhibitors in pediatric patients with PH. PDE5 inhibitors are effective agents for cardiovascular and oxygenation end points in pediatric PH and important components of a multimodal pharmacotherapeutic approach to this growing challenge. Additional studies are needed to define optimal PH therapy in childhood.
Topics: Blood Flow Velocity; Cardiac Catheterization; Cardiac Output; Cardiotonic Agents; Child; Dose-Response Relationship, Drug; Echocardiography; Exercise Tolerance; Humans; Hypertension, Pulmonary; Length of Stay; Off-Label Use; Oxygen; Oxygen Consumption; Phosphodiesterase 5 Inhibitors; Pulmonary Circulation; Respiration, Artificial; Sildenafil Citrate
PubMed: 28235796
DOI: 10.1542/peds.2016-1450 -
Annals of Translational Medicine Jan 2018It is well-known that positive end-expiratory pressure (PEEP) can prevent ventilator-induced lung injury (VILI) and improve pulmonary physiology in animals with injured... (Review)
Review
It is well-known that positive end-expiratory pressure (PEEP) can prevent ventilator-induced lung injury (VILI) and improve pulmonary physiology in animals with injured lungs. It's uncertain whether PEEP has similar effects in animals with uninjured lungs. A systematic review of randomized controlled trials (RCTs) comparing different PEEP levels in animals with uninjured lungs was performed. Trials in animals with injured lungs were excluded, as were trials that compared ventilation strategies that also differed with respect to other ventilation settings, e.g., tidal volume size. The search identified ten eligible trials in 284 animals, including rodents and small as well as large mammals. Duration of ventilation was highly variable, from 1 to 6 hours and tidal volume size varied from 7 to 60 mL/kg. PEEP ranged from 3 to 20 cmHO, and from 0 to 5 cmHO, in the 'high PEEP' or 'PEEP' arms, and in the 'low PEEP' or 'no PEEP' arms, respectively. Definitions used for lung injury were quite diverse, as were other outcome measures. The effects of PEEP, at any level, on lung injury was not straightforward, with some trials showing less injury with 'high PEEP' or 'PEEP' and other trials showing no benefit. In most trials, 'high PEEP' or 'PEEP' was associated with improved respiratory system compliance, and better oxygen parameters. However, 'high PEEP' or 'PEEP' was also associated with occurrence of hypotension, a reduction in cardiac output, or development of hyperlactatemia. There were no differences in mortality. The number of trials comparing 'high PEEP' or 'PEEP' with 'low PEEP' or 'no PEEP' in animals with uninjured lungs is limited, and results are difficult to compare. Based on findings of this systematic review it's uncertain whether PEEP, at any level, truly prevents lung injury, while most trials suggest potential harmful effects on the systemic circulation.
PubMed: 29430442
DOI: 10.21037/atm.2017.12.05 -
The Canadian Journal of Cardiology Dec 2016Combination therapy (CT) for patients with pulmonary arterial hypertension (PAH) has been recommended for many years, despite weak evidence of efficacy over monotherapy... (Review)
Review
BACKGROUND
Combination therapy (CT) for patients with pulmonary arterial hypertension (PAH) has been recommended for many years, despite weak evidence of efficacy over monotherapy (MT). A previous meta-analysis comparing CT vs MT with pulmonary vasodilators failed to demonstrate a clear reduction in clinical worsening events.
METHODS
We searched for relevant articles in PubMed, EMBASE, the Cochrane Database, and clinicaltrials.gov; we also manually searched review articles and conference abstracts from 1980-December 2015. Target articles were double-blinded studies of 2 or more pulmonary vasodilators given in combination vs monotherapy for treatment of patients with PAH. The principal outcome of interest was "combined clinical worsening" (CCW) events (including but not limited to death or hospitalization). Data on physiological outcomes were also explored. Meta-analysis was performed using the DerSimonian and Laird random-effects model.
RESULTS
We extracted data from 18 randomized controlled trials (RCTs) (N = 4162). CT was associated with a significant 38% reduction of risk of CCW (15 RCTs: n = 3906; risk ratio [RR], 0.62; 95% confidence interval [CI], 0.50-0.77). This reduction in risk was driven by a reduction in nonfatal end points (12 RCTs: n = 2611; RR, 0.56; 95% CI, 0.40-0.78) and not by a reduction of mortality (12 RCTs: n = 2717; RR, 0.79; 95% CI, 0.53-1.17). CT was also associated with improvement in 6-minute walking distance (10 RCTs: n = 1553; weighted mean difference [WMD], +23.0 m; 95% CI, 15.9-30.1), improved functional class (9 RCTs: n = 1737; RR, 1.26; 95% CI, 1.05-1.51), and beneficial effects on pulmonary hemodynamics such as cardiac index (WMD, +0.35 L/min/m; 95% CI, 0.14-0.56).
CONCLUSIONS
In this highly comprehensive meta-analysis, CT reduces the risk of CCW events in patients with PAH and brings physiological improvement.
Topics: Drug Therapy, Combination; Humans; Hypertension, Pulmonary; Pulmonary Circulation; Randomized Controlled Trials as Topic; Risk Assessment; Treatment Outcome; Vasodilation; Vasodilator Agents
PubMed: 27378592
DOI: 10.1016/j.cjca.2016.03.004 -
Journal of Intensive Care Medicine May 2024During cardiopulmonary resuscitation, intravenous thrombolytics are commonly used for patients whose underlying etiology of cardiac arrest is presumed to be related to... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
During cardiopulmonary resuscitation, intravenous thrombolytics are commonly used for patients whose underlying etiology of cardiac arrest is presumed to be related to pulmonary embolism (PE).
METHODS
We performed a systematic review and meta-analysis of the existing literature that focused on the use of thrombolytics for cardiac arrest due to presumed or confirmed PE. Outcomes of interest were return of spontaneous circulation (ROSC), survival to hospital discharge, neurologically-intact survival, and bleeding complications.
RESULTS
Thirteen studies with a total of 803 patients were included in this review. Most studies included were single-armed and retrospective. Thrombolytic agent and dose were heterogeneous between studies. Among those with control groups, intravenous thrombolysis was associated with higher rates of ROSC (OR 2.55, 95% CI = 1.50-4.34), but without a significant difference in survival to hospital discharge (OR 1.41, 95% CI = 0.79-2.41) or bleeding complications (OR 2.21, 0.95-5.17).
CONCLUSIONS
Use of intravenous thrombolytics in cardiac arrest due to confirmed or presumed PE is associated with increased ROSC but not survival to hospital discharge or change in bleeding complications. Larger randomized studies are needed. Currently, we recommend continuing to follow existing consensus guidelines which support use of thrombolytics for this indication.
Topics: Humans; Fibrinolytic Agents; Retrospective Studies; Pulmonary Embolism; Heart Arrest; Cardiopulmonary Resuscitation; Out-of-Hospital Cardiac Arrest
PubMed: 38037310
DOI: 10.1177/08850666231214754 -
Journal of Traditional Chinese Medicine... Feb 2015To assess the efficacy and safety of Chinese patent medicine (CPM) with the principle of tonifying Qi, promoting blood circulation by removing blood stasis, and... (Review)
Review
Chinese patent medicine for chronic obstructive pulmonary disease based on principles of tonifying Qi, promoting blood circulation by removing blood stasis, and resolving phlegm: a systematic review of randomized controlled trials.
OBJECTIVE
To assess the efficacy and safety of Chinese patent medicine (CPM) with the principle of tonifying Qi, promoting blood circulation by removing blood stasis, and resolving phlegm (TQ-PBC-RP) in the management of stable chronic obstructive pulmonary disease (COPD).
METHODS
A systematic review of randomized controlled trials (RCTs) identified from electronic databases and print was conducted. RCTs testing CPMs with TQ-PBC-RP against any type of controlled intervention in patients with stable COPD and assessing clinically relevant outcomes were included. Methodological quality was evaluated with the risk of bias tool according to systematic review handbook 5.0.2. Quality of evidence was estimated by the rating approach developed by the Grading of Recommendations, Assessment, Development, and Evaluation Working Group.
RESULTS
Thirteen eligible RCTs with 12 oral CPMs were tested. Significant differences between groups in favor of CPMs were not reported in all trials. Most trials included were deemed to be of low methodological quality with poor evidence quality. Because of large data heterogeneity, statistical pooling was not performed for all outcomes.
CONCLUSION
The effectiveness of CPM in the treatment of stable COPD is not supported by evidence. Currently, evidence from RCTs is scarce and methodologically weak. Considering the popularity of CPMs among patients undergoing COPD, rigorously designed trials are warranted.
Topics: Blood Circulation; Drugs, Chinese Herbal; Humans; Pulmonary Disease, Chronic Obstructive; Qi; Randomized Controlled Trials as Topic
PubMed: 25842721
DOI: 10.1016/s0254-6272(15)30001-7 -
Pulmonary Circulation 2020Acute pulmonary embolism is the third most common cause of cardiovascular death. Pulmonary embolism increases right ventricular afterload, which causes right ventricular... (Review)
Review
Acute pulmonary embolism is the third most common cause of cardiovascular death. Pulmonary embolism increases right ventricular afterload, which causes right ventricular failure, circulatory collapse and death. Most treatments focus on removal of the mechanical obstruction caused by the embolism, but pulmonary vasoconstriction is a significant contributor to the increased right ventricular afterload and is often left untreated. Pulmonary thromboembolism causes mechanical obstruction of the pulmonary vasculature coupled with a complex interaction between humoral factors from the activated platelets, endothelial effects, reflexes and hypoxia to cause pulmonary vasoconstriction that worsens right ventricular afterload. Vasoconstrictors include serotonin, thromboxane, prostaglandins and endothelins, counterbalanced by vasodilators such as nitric oxide and prostacyclins. Exogenous administration of pulmonary vasodilators in acute pulmonary embolism seems attractive but all come with a risk of systemic vasodilation or worsening of pulmonary ventilation-perfusion mismatch. In animal models of acute pulmonary embolism, modulators of the nitric oxide-cyclic guanosine monophosphate-protein kinase G pathway, endothelin pathway and prostaglandin pathway have been investigated. But only a small number of clinical case reports and prospective clinical trials exist. The aim of this review is to give an overview of the causes of pulmonary embolism-induced pulmonary vasoconstriction and of experimental and human investigations of pulmonary vasodilation in acute pulmonary embolism.
PubMed: 32180938
DOI: 10.1177/2045894019899775 -
Annals of the American Thoracic Society Jun 2023Transbronchial lung biopsies (TBLBs) are commonly performed by pulmonologists. Most providers consider pulmonary hypertension to be at least a relative contraindication... (Meta-Analysis)
Meta-Analysis
Transbronchial lung biopsies (TBLBs) are commonly performed by pulmonologists. Most providers consider pulmonary hypertension to be at least a relative contraindication to TBLB. This practice is based primarily on expert opinion, as there are very few patient outcomes data backing it. We performed a systematic review and meta-analysis of previously published studies to determine the safety of TBLB in patients with pulmonary hypertension. The MEDLINE, Embase, Scopus, and Google Scholar databases were searched for pertinent studies. The quality of the included studies was assessed using the Newcastle-Ottawa Scale. Meta-analysis was performed using MedCalc version 20.118 to calculate the weighted pooled relative risk of complications in patients with pulmonary hypertension. Nine studies with a total of 1,699 patients were included in the meta-analysis. On the basis of the Newcastle-Ottawa Scale, the risk of bias was low in the included studies. The overall weighted relative risk of bleeding with TBLB in patients with pulmonary hypertension was 1.01 (95% confidence interval, 0.71-1.45) compared with patients without pulmonary hypertension. Heterogeneity was low; therefore, the fixed-effects model was used. In a subgroup analysis of three studies, the overall weighted relative risk of significant hypoxia in patients with pulmonary hypertension was 2.06 (95% confidence interval, 1.12-3.76). Our results show that the patients with pulmonary hypertension do not have a significantly elevated risk of bleeding with TBLB compared with control subjects. We hypothesize that significant postbiopsy bleeding might be preferentially originating from bronchial artery circulation as opposed to pulmonary artery circulation, much like episodes of massive spontaneous hemoptysis. This hypothesis can explain our results, as in this scenario, elevated pulmonary arterial pressure would not be expected to have a bearing on the risk of post-TBLB bleeding. Most of the studies in our analysis included patients with mild to moderate pulmonary hypertension and it is not clear if our results can be extrapolated to patients with severe pulmonary hypertension. We noted that the patients with pulmonary hypertension were at a higher risk of developing hypoxia and needing a longer duration of mechanical ventilation with TBLB compared with control subjects. Further studies are needed to better understand the origin and pathophysiology of post-TBLB bleeding.
Topics: Humans; Hypertension, Pulmonary; Bronchoscopy; Biopsy; Lung Diseases; Hypoxia; Lung
PubMed: 36867520
DOI: 10.1513/AnnalsATS.202211-965OC -
International Journal of Cardiology Jan 2015
Meta-Analysis Review
Topics: Exercise Therapy; Humans; Hypertension, Pulmonary; Randomized Controlled Trials as Topic
PubMed: 25464238
DOI: 10.1016/j.ijcard.2014.10.161 -
Pulmonary Circulation Jul 2022Pulmonary thromboembolic events have been linked to coronavirus disease 2019 (COVID-19), but their incidence and long-term sequelae remain unclear. We performed a... (Review)
Review
Pulmonary thromboembolic events have been linked to coronavirus disease 2019 (COVID-19), but their incidence and long-term sequelae remain unclear. We performed a systematic literature review to investigate the incidence of pulmonary embolism (PE), microthrombi, thrombosis in situ (thromboinflammatory disease), and chronic thromboembolic pulmonary hypertension (CTEPH) during and after COVID-19. PubMed and the World Health Organization Global Research Database were searched on May 7, 2021. Hospital cohort and database studies reporting data for ≥1000 patients and autopsy studies reporting data for ≥20 patients were included. Results were summarized descriptively. We screened 1438 records and included 41 references (32 hospital/database studies and 9 autopsy studies). The hospital/database studies reported the incidence of PE but not CTEPH, microthrombi, or thromboinflammatory disease. PE incidence varied widely (0%-1.1% of outpatients, 0.9%-8.2% of hospitalized patients, and 1.8%-18.9% of patients in intensive care). One study reported PE events occurring within 45 days after hospital discharge (incidence in discharged patients: 0.2%). Segmental arteries were generally the most common location for PE. In autopsy studies, PE, thromboinflammatory disease, and microthrombi were reported in 6%-23%, 43%-100%, and 45%-84% of deceased patients, respectively. Overall, the included studies mostly focused on PE during the acute phase of COVID-19. The results demonstrate the challenges of identifying and characterizing vascular abnormalities using current protocols (e.g., visual computed tomography reads). Further research is needed to detect subtle pulmonary vascular abnormalities, distinguish thromboinflammatory disease from PE, optimize treatment, and assess the incidence of long-term sequelae after COVID-19.
PubMed: 35942076
DOI: 10.1002/pul2.12113