scholarly journals Right Ventricular Response to Acute Hypoxia Exposure: A Systematic Review

2022 ◽  
Vol 12 ◽  
Author(s):  
Argen Mamazhakypov ◽  
Meerim Sartmyrzaeva ◽  
Nadira Kushubakova ◽  
Melis Duishobaev ◽  
Abdirashit Maripov ◽  
...  
Keyword(s):  
Systematic Review ◽  
High Altitude ◽  
Prospective Studies ◽  
Acute Hypoxia ◽  
Small Sample ◽  
Reproducible Research ◽  
Simulated Altitude ◽  
Hypoxia Exposure ◽  
Study Designs ◽  
Rv Function

Background: Acute hypoxia exposure is associated with an elevation of pulmonary artery pressure (PAP), resulting in an increased hemodynamic load on the right ventricle (RV). In addition, hypoxia may exert direct effects on the RV. However, the RV responses to such challenges are not fully characterized. The aim of this systematic review was to describe the effects of acute hypoxia on the RV in healthy lowland adults.Methods: We systematically reviewed PubMed and Web of Science and article references from 2005 until May 2021 for prospective studies evaluating echocardiographic RV function and morphology in healthy lowland adults at sea level and upon exposure to simulated altitude or high-altitude.Results: We included 37 studies in this systematic review, 12 of which used simulated altitude and 25 were conducted in high-altitude field conditions. Eligible studies reported at least one of the RV variables, which were all based on transthoracic echocardiography assessing RV systolic and diastolic function and RV morphology. The design of these studies significantly differed in terms of mode of ascent to high-altitude, altitude level, duration of high-altitude stay, and timing of measurements. In the majority of the studies, echocardiographic examinations were performed within the first 10 days of high-altitude induction. Studies also differed widely by selectively reporting only a part of multiple RV parameters. Despite consistent increase in PAP documented in all studies, reports on the changes of RV function and morphology greatly differed between studies.Conclusion: This systematic review revealed that the study reports on the effects of acute hypoxia on the RV are controversial and inconclusive. This may be the result of significantly different study designs, non-compliance with international guidelines on RV function assessment and limited statistical power due to small sample sizes. Moreover, the potential impact of other factors such as gender, age, ethnicity, physical activity, mode of ascent and environmental factors such as temperature and humidity on RV responses to hypoxia remained unexplored. Thus, this comprehensive overview will promote reproducible research with improved study designs and methods for the future large-scale prospective studies, which eventually may provide important insights into the RV response to acute hypoxia exposure.

A historical cohort of temporal lobe surgery for medically refractory epilepsy: a systematic review and meta-analysis to guide future nonrandomized controlled trial studies

2020 ◽  
Vol 133 (1) ◽  
pp. 71-78 ◽  
Author(s):  
Anthony T. Lee ◽  
John F. Burke ◽  
Pranathi Chunduru ◽  
Annette M. Molinaro ◽  
Robert Knowlton ◽  
...  
Keyword(s):  
Systematic Review ◽  
Temporal Lobe ◽  
Epilepsy Surgery ◽  
Refractory Epilepsy ◽  
Meta Analysis ◽  
Small Sample ◽  
Seizure Freedom ◽  
Level I ◽  
Study Designs ◽  
Medically Refractory Epilepsy

OBJECTIVERecent trials for temporal lobe epilepsy (TLE) highlight the challenges of investigating surgical outcomes using randomized controlled trials (RCTs). Although several reviews have examined seizure-freedom outcomes from existing data, there is a need for an overall seizure-freedom rate estimated from level I data as investigators consider other methods besides RCTs to study outcomes related to new surgical interventions.METHODSThe authors performed a systematic review and meta-analysis of the 3 RCTs of TLE in adults and report an overall surgical seizure-freedom rate (Engel class I) composed of level I data. An overall seizure-freedom rate was also collected from level II data (prospective cohort studies) for validation. Eligible studies were identified by filtering a published Cochrane meta-analysis of epilepsy surgery for RCTs and prospective studies, and supplemented by searching indexed terms in MEDLINE (January 1, 2012–April 1, 2018). Retrospective studies were excluded to minimize heterogeneity in patient selection and reporting bias. Data extraction was independently reverified and pooled using a fixed-effects model. The primary outcome was overall seizure freedom following surgery. The historical benchmark was applied in a noninferiority study design to compare its power to a single-study cohort.RESULTSThe overall rate of seizure freedom from level I data was 72.4% (55/76 patients, 3 RCTs), which was nearly identical to the overall seizure-freedom rate of 71.7% (1325/1849 patients, 18 studies) from prospective cohorts (z = 0.134, p = 0.89; z-test). Seizure-freedom rates from level I and II studies were consistent over the years of publication (R2< 0.01, p = 0.73). Surgery resulted in markedly improved seizure-free outcomes compared to medical management (RR 10.82, 95% CI 3.93–29.84, p < 0.01; 2 RCTs). Noninferiority study designs in which the historical benchmark was used had significantly higher power at all difference margins compared to using a single cohort alone (p < 0.001, Bonferroni’s multiple comparison test).CONCLUSIONSThe overall rate of seizure freedom for temporal lobe surgery is approximately 70% for medically refractory epilepsy. The small sample size of the RCT cohort underscores the need to move beyond standard RCTs for epilepsy surgery. This historical seizure-freedom rate may serve as a useful benchmark to guide future study designs for new surgical treatments for refractory TLE.

scholarly journals The impact of selection criteria and study design on reported survival outcomes in extracorporeal oxygenation cardiopulmonary resuscitation (ECPR): a systematic review and meta-analysis

2021 ◽  
Vol 29 (1) ◽  
Author(s):  
Sameer Karve ◽  
Dominique Lahood ◽  
Arne Diehl ◽  
Aidan Burrell ◽  
David H. Tian ◽  
...  
Keyword(s):  
Systematic Review ◽  
Study Design ◽  
Prospective Studies ◽  
Selection Criteria ◽  
Meta Analysis ◽  
Inclusion Criteria ◽  
Newcastle Ottawa Scale ◽  
Study Designs ◽  
Based Medicine ◽  
The Impact

Abstract Background The use of extracorporeal membrane oxygenation (ECMO) during cardiac arrest (ECPR) has increased exponentially. However, reported outcomes vary considerably due to differing study designs and selection criteria. This review assessed the impact of pre-defined selection criteria on ECPR survival. Methods Systematic review applying PRISMA guidelines. We searched Medline, Embase, and Evidence-Based Medicine Reviews for RCTs and observational studies published from January 2000 to June 2021. Adult patients (> 12 years) receiving ECPR were included. Two investigators reviewed and extracted data on study design, number and type of inclusion criteria. Study quality was assessed using the Newcastle–Ottawa Scale (NOS). Outcomes included overall and neurologically favourable survival. Meta-analysis and meta-regression were performed. Results 67 studies were included: 14 prospective and 53 retrospective. No RCTs were identified at time of search. The number of inclusion criteria to select ECPR patients (p = 0.292) and study design (p = 0.962) was not associated with higher favourable neurological survival. However, amongst prospective studies, increased number of inclusion criteria was associated with improved outcomes in both OHCA and IHCA cohorts. (β = 0.12, p = 0.026) and arrest to ECMO flow time was predictive of survival. (β = -0.023, p < 0.001). Conclusions Prospective studies showed number of selection criteria and, in particular, arrest to ECMO time were associated with significant improved survival. Well-designed prospective studies assessing the relative importance of criteria as well as larger efficacy studies are required to ensure appropriate application of what is a costly intervention.

Ventilatory interaction between hypoxia and [H+] at chemoreceptors of man

1975 ◽  
Vol 39 (2) ◽  
pp. 292-296 ◽  
Author(s):  
R. A. Gabel ◽  
R. B. Weiskopf
Keyword(s):  
Experimental Design ◽  
High Altitude ◽  
Sea Level ◽  
Acute Hypoxia ◽  
Simulated Altitude ◽  
Peripheral Chemoreceptor ◽  
Peripheral Chemoreceptors ◽  
Central Chemoreceptors ◽  
Progressive Hypoxia ◽  
The Mean

By measuring ventilation during isocapnic progressive hypoxia, peripheral chemoreceptor sensitivity to acute hypoxia (deltaV40) was measured in five normal young men under four sets of conditions: 1) at sea level at the subject's resting PCO2, 2) at sea level with PCO2 5 Torr above resting PCO2, 3) after 24 h at a simulated altitude of 4,267 m (PB = 447 Torr) at the subject's resting PCO2 measured during acute hyperoxia, and 4) after 24 h at high altitude, with PCO2 elevated to the subject's sea-level resting PCO2. With this experimental design, we were able to systematically vary the PCO2 and [H+] at the peripheral and central chemoreceptors of man. When mean pHa was decreased from 7.424 to 7.377 without significant change in PACO2, the mean deltaV40 increased from 18.0 to 55.9 1/min. Conversely, when mean PACO2 was altered between 33.8 and 41.6 Torr with pHa held relatively constant, the mean deltaV40 did not change. This suggests that it is the H+ and not CO2 which interacts with hypoxia in stimulating the ventilation of man. An additional finding was that the intrinsic sensitivity of the peripheral chemoreceptors to acute hypoxia did not change during 24 h of acclimatization to high altitude.

scholarly journals Physical Rehabilitation Interventions for Post-mTBI Symptoms Lasting Greater Than 2 Weeks: Systematic Review

2016 ◽  
Vol 96 (11) ◽  
pp. 1753-1763 ◽  
Author(s):  
Catherine Quatman-Yates ◽  
Amanda Cupp ◽  
Cherryanne Gunsch ◽  
Tonya Haley ◽  
Steve Vaculik ◽  
...  
Keyword(s):  
Systematic Review ◽  
Physical Therapists ◽  
Data Extraction ◽  
Small Sample ◽  
Physical Rehabilitation ◽  
Cochrane Library ◽  
Minimal Risk ◽  
Exercise Interventions ◽  
Small Sample Sizes ◽  
Study Designs

Abstract Background Heightened awareness of the lasting effects of mild traumatic brain injury (mTBI) has amplified interest in interventions that facilitate recovery from persistent post-mTBI symptoms. Purpose The purpose of this study was to systematically review the literature to identify potential physical rehabilitation interventions that are safe, feasible, and appropriate for physical therapists to utilize with patients with persistent mTBI-related symptoms. Data Sources The electronic databases PubMed, Cochrane Library, CINAHL, Scopus, SPORTDiscus, and Web of Science were systematically searched from database inception until June 2015. Study Selection Studies were included if they utilized physical rehabilitation interventions and the study's participants had a diagnosis of mTBI, a mean age of 8 years or older, and symptoms persisting an average of 2 weeks or longer. Exclusion criteria included blast injuries, diagnosis of moderate or severe TBI, or psychosis. Data Extraction Data extraction and methodological risk of bias assessments were performed for each study. Data Synthesis Eight studies with a range of study designs, intervention types, and outcome measures were included. The interventions investigated by the included studies were categorized into 3 types: physiological, vestibulo-ocular, and cervicogenic. Limitations The identified studies had several significant limitations including: small sample sizes and low-level study designs. Conclusions The results of this systematic review indicate that several physical rehabilitation options with minimal risk for negative outcomes are available for treating patients experiencing persistent post-mTBI symptoms. These options include: vestibular, manual, and progressive exercise interventions. Conclusions surrounding efficacy and ideal dosing parameters for these interventions are limited at this time due to the small number of studies, the range of interventional protocols, and lower levels of study design.

Transplantation of Adipose-derived Cells for Periodontal Regeneration: A Systematic Review

2019 ◽  
Vol 14 (6) ◽  
pp. 504-518 ◽  
Author(s):  
Dilcele Silva Moreira Dziedzic ◽  
Bassam Felipe Mogharbel ◽  
Priscila Elias Ferreira ◽  
Ana Carolina Irioda ◽  
Katherine Athayde Teixeira de Carvalho
Keyword(s):  
Systematic Review ◽  
Animal Models ◽  
Platelet Rich Plasma ◽  
Periodontal Regeneration ◽  
In Vitro Studies ◽  
In Vivo Studies ◽  
Cell Sources ◽  
Study Designs

This systematic review evaluated the transplantation of cells derived from adipose tissue for applications in dentistry. SCOPUS, PUBMED and LILACS databases were searched for in vitro studies and pre-clinical animal model studies using the keywords “ADIPOSE”, “CELLS”, and “PERIODONTAL”, with the Boolean operator “AND”. A total of 160 titles and abstracts were identified, and 29 publications met the inclusion criteria, 14 in vitro and 15 in vivo studies. In vitro studies demonstrated that adipose- derived cells stimulate neovascularization, have osteogenic and odontogenic potential; besides adhesion, proliferation and differentiation on probable cell carriers. Preclinical studies described improvement of bone and periodontal healing with the association of adipose-derived cells and the carrier materials tested: Platelet Rich Plasma, Fibrin, Collagen and Synthetic polymer. There is evidence from the current in vitro and in vivo data indicating that adipose-derived cells may contribute to bone and periodontal regeneration. The small quantity of studies and the large variation on study designs, from animal models, cell sources and defect morphology, did not favor a meta-analysis. Additional studies need to be conducted to investigate the regeneration variability and the mechanisms of cell participation in the processes. An overview of animal models, cell sources, and scaffolds, as well as new perspectives are provided for future bone and periodontal regeneration study designs.

scholarly journals Spleen contraction elevates hemoglobin concentration at high altitude during rest and exercise

2020 ◽  
Vol 120 (12) ◽  
pp. 2693-2704
Author(s):  
Erika Schagatay ◽  
Alexander Lunde ◽  
Simon Nilsson ◽  
Oscar Palm ◽  
Angelica Lodin-Sundström
Keyword(s):  
High Altitude ◽  
Acute Hypoxia ◽  
Arterial Oxygen Saturation ◽  
Hemoglobin Concentration ◽  
Step Test ◽  
Arterial Oxygen ◽  
Spleen Volume ◽  
Spleen Contraction ◽  
Response To Exercise ◽  
Rest And Exercise

Abstract Purpose Hypoxia and exercise are known to separately trigger spleen contraction, leading to release of stored erythrocytes. We studied spleen volume and hemoglobin concentration (Hb) during rest and exercise at three altitudes. Methods Eleven healthy lowlanders did a 5-min modified Harvard step test at 1370, 3700 and 4200 m altitude. Spleen volume was measured via ultrasonic imaging and capillary Hb with Hemocue during rest and after the step test, and arterial oxygen saturation (SaO2), heart rate (HR), expiratory CO2 (ETCO2) and respiratory rate (RR) across the test. Results Resting spleen volume was reduced with increasing altitude and further reduced with exercise at all altitudes. Mean (SE) baseline spleen volume at 1370 m was 252 (20) mL and after exercise, it was 199 (15) mL (P < 0.01). At 3700 m, baseline spleen volume was 231 (22) mL and after exercise 166 (12) mL (P < 0.05). At 4200 m baseline volume was 210 (23) mL and after exercise 172 (20) mL (P < 0.05). After 10 min, spleen volume increased to baseline at all altitudes (NS). Baseline Hb increased with altitude from 138.9 (6.1) g/L at 1370 m, to 141.2 (4.1) at 3700 m and 152.4 (4.0) at 4200 m (P < 0.01). At all altitudes Hb increased from baseline during exercise to 146.8 (5.7) g/L at 1370 m, 150.4 (3.8) g/L at 3700 m and 157.3 (3.8) g/L at 4200 m (all P < 0.05 from baseline). Hb had returned to baseline after 10 min rest at all altitudes (NS). The spleen-derived Hb elevation during exercise was smaller at 4200 m compared to 3700 m (P < 0.05). Cardiorespiratory variables were also affected by altitude during both rest and exercise. Conclusions The spleen contracts and mobilizes stored red blood cells during rest at high altitude and contracts further during exercise, to increase oxygen delivery to tissues during acute hypoxia. The attenuated Hb response to exercise at the highest altitude is likely due to the greater recruitment of the spleen reserve during rest, and that maximal spleen contraction is reached with exercise.

scholarly journals The Use of Pulse Oximetry in the Assessment of Acclimatization to High Altitude

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1263
Author(s):  
Tobias Dünnwald ◽  
Roland Kienast ◽  
David Niederseer ◽  
Martin Burtscher
Keyword(s):  
Pulse Oximetry ◽  
High Altitude ◽  
Acute Mountain Sickness ◽  
Measurement Methods ◽  
Peripheral Oxygen Saturation ◽  
Hypoxia Exposure ◽  
Lower Spo2 ◽  
Time Courses ◽  
Finger Pulse ◽  
Pulse Oximeters

Background: Finger pulse oximeters are widely used to monitor physiological responses to high-altitude exposure, the progress of acclimatization, and/or the potential development of high-altitude related diseases. Although there is increasing evidence for its invaluable support at high altitude, some controversy remains, largely due to differences in individual preconditions, evaluation purposes, measurement methods, the use of different devices, and the lacking ability to interpret data correctly. Therefore, this review is aimed at providing information on the functioning of pulse oximeters, appropriate measurement methods and published time courses of pulse oximetry data (peripheral oxygen saturation, (SpO2) and heart rate (HR), recorded at rest and submaximal exercise during exposure to various altitudes. Results: The presented findings from the literature review confirm rather large variations of pulse oximetry measures (SpO2 and HR) during acute exposure and acclimatization to high altitude, related to the varying conditions between studies mentioned above. It turned out that particularly SpO2 levels decrease with acute altitude/hypoxia exposure and partly recover during acclimatization, with an opposite trend of HR. Moreover, the development of acute mountain sickness (AMS) was consistently associated with lower SpO2 values compared to individuals free from AMS. Conclusions: The use of finger pulse oximetry at high altitude is considered as a valuable tool in the evaluation of individual acclimatization to high altitude but also to monitor AMS progression and treatment efficacy.

scholarly journals Vital Pulp Therapy in Permanent Mature Posterior Teeth with Symptomatic Irreversible Pulpitis: A Systematic Review of Treatment Outcomes

Medicina ◽  
2021 ◽  
Vol 57 (6) ◽  
pp. 573
Author(s):  
João Miguel Santos ◽  
Joana F. Pereira ◽  
Andréa Marques ◽  
Diana B. Sequeira ◽  
Shimon Friedman
Keyword(s):  
Systematic Review ◽  
Root Canal ◽  
Small Sample ◽  
Risk Of Bias ◽  
Root Canal Treatment ◽  
Cochrane Library ◽  
Posterior Teeth ◽  
Pulp Therapy ◽  
Vital Pulp Therapy ◽  
Irreversible Pulpitis

Background and Objectives: Symptomatic irreversible pulpitis in permanent mature teeth is a common indication for nonsurgical root canal treatment (NSRCT), but contemporary studies have reported on vital pulp therapy (VPT) applied in such teeth as a less invasive treatment. This systematic review assessed the outcomes of VPT, including partial and full pulpotomy performed with hydraulic calcium silicate cements (HCSCs) in permanent mature posterior teeth diagnosed with symptomatic irreversible pulpitis. Materials and Methods: The PRISMA guidelines were followed. The search strategy included PubMed®, EMBASE, Cochrane library and grey literature electronic databases. The quality assessment of the identified studies followed the Cochrane Collaboration Risk of Bias, ROBINS-I and Newcastle–Ottawa Scale tools. Results: The search of primary databases identified 142 articles, of which 9 randomized controlled trials and 3 prospective cohort studies were selected for review. The risk-of-bias was assessed as ‘high’ or ‘serious’, ‘fair’, and ‘low’ for three, seven and two articles, respectively. One to five years after VPT using HCSCs, the success rates mostly ranged from 78 to 90%. Based on two articles, the outcomes of the VPT and NSRCT were comparable at one and five years. Despite the necessity for the intra-operative pulp assessment in VPT procedures, the majority of the studies did not fully report on this step or on the time needed to achieve hemostasis. Small sample sizes, of under 23 teeth, were reported in three studies. Conclusions: The reviewed 12 articles reported favorable outcomes of the VPT performed with HCSCs in permanent mature posterior teeth with symptomatic irreversible pulpitis, with radiographic success in the range of 81 to 90%. Two articles suggested comparable outcomes of the VPT and root canal treatment. Universal case selection and outcome criteria needs to be established for VPT when considered as an alternative to NSRCT. This evidence supports the need for further research comparing longer-term outcomes of both of the treatment modalities.

scholarly journals Treatment strategies for cerebrospinal shunt infections: a systematic review of observational studies

BMJ Open ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. e038978
Author(s):  
Joan L Robinson ◽  
Dolores Freire ◽  
Liza Bialy
Keyword(s):  
Systematic Review ◽  
Small Sample Size ◽  
Treatment Strategies ◽  
Small Sample ◽  
Cochrane Library ◽  
Csf Shunt ◽  
Entry Site ◽  
Recurrence Rates ◽  
Ovid Medline ◽  
Shunt Infections

ObjectiveA systematic review was conducted of studies comparing time to cerebrospinal fluid (CSF) sterilisation or rate of recurrence with different treatment strategies for CSF shunt infections.MethodsA librarian-directed search was conducted of Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Ovid Medline Daily and Ovid Medline, Ovid Embase, Wiley Cochrane Library, CINAHL Plus with Full Text via EBSCOhost, Scopus Advanced Search, and Web of Science Core Collection from 1990 to May 2019. Studies of any design that compared outcomes in groups of any age with different management strategies were included. Studies that compared complete versus incomplete shunt removal were excluded. Quality assessment was performed with the Newcastle-Ottawa Scale.ResultsThe search identified 2208 records, of which 8 met the inclusion criteria. All were cohort studies of moderate quality. Four studies compared the duration of antibiotics; none demonstrates that a longer course prevented recurrences. Two studies analysed addition of rifampin, with one showing a decrease in recurrences while the other had a small sample size. No studies analysed the addition of intraventricular antibiotics, but one showed equally good results with once versus twice daily administration. One study reported no difference in recurrences with placement of antibiotic-impregnated catheters. Recurrence rates did not differ with shunt replacement minimum of 7 days vs less than 7 days after CSF became sterile. There were no recurrences in either group when shunt replacement was performed after sterile CSF cultures were obtained at 24 vs 48 hours after antibiotics were discontinued. A new shunt entry site did not decrease recurrences.DiscussionThe main limitations are the lack of high-quality studies, the small sample sizes and the heterogeneity which precluded meta-analysis. Addition of rifampin for staphylococcal infections may decrease relapse but requires further study.

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