Effect of withdrawal of respiratory CO2 oscillations on respiratory control at rest

1991 ◽  
Vol 70 (4) ◽  
pp. 1601-1606 ◽  
Author(s):  
E. Takahashi ◽  
I. Tateishi ◽  
K. Yamamoto ◽  
T. Mikami
Keyword(s):  
Resting Metabolic Rate ◽  
Respiratory Control ◽  
Afferent Input ◽  
Respiratory Center ◽  
Arterial Pco2 ◽  
Baseline Drift ◽  
Double Lumen Endotracheal Tube ◽  
Arterial Ph ◽  
The Mean ◽  
The Difference

We examined the effect of sudden withdrawal of respiratory oscillations of arterial PCO2 (CO2 oscillations) at resting metabolic rate on the control of respiration in 11 anesthetized paralyzed vagotomized dogs in normoxic normocapnia. A double-lumen endotracheal tube was inserted so that the left and right lungs were ventilated independently. By alternately ventilating each lung, we could completely abolish CO2 oscillations without affecting the mean blood gas levels (withdrawal of CO2 oscillations). The CO2 oscillation was calculated from arterial pH oscillation measured by a rapidly responding intra-arterial pH electrode. Respiratory center output was monitored by use of a moving time average of the phrenic neurogram. A 3-min period of withdrawal of CO2 oscillations was bracketed by two control periods (simultaneous ventilation of lungs for 3 min) to avoid the confounding effect of the baseline drift in the respiratory center output. The amplitude of the CO2 oscillations in the control was 2.33 +/- 0.89 (SD) Torr. When the difference in the mean level of arterial PCO2 between the control and withdrawal of CO2 oscillations was minimized (-0.09 +/- 0.54 Torr; P greater than 0.25), we found negligible change in the minute phrenic activity during withdrawal of CO2 oscillations (-0.02 +/- 6.11% of the control, P greater than 0.98, n = 49; 99% confidence interval -2.36 to 2.32%). Thus we conclude that the maintenance of normal respiration at rest is not critically dependent on a phasic afferent input to the respiratory center arising from respiratory CO2 oscillations.

Mechanisms of gas exchange with different gases during constant-flow ventilation

1990 ◽  
Vol 68 (1) ◽  
pp. 88-93 ◽  
Author(s):  
F. J. Chen ◽  
A. S. Menon ◽  
S. V. Lichtenstein ◽  
N. Zamel ◽  
A. S. Slutsky
Keyword(s):  
Gas Exchange ◽  
Physical Properties ◽  
Flow Rate ◽  
Constant Flow ◽  
Catheter Position ◽  
Arterial Pco2 ◽  
The Mean ◽  
The Difference ◽  
The Individual ◽  
Different Gases

To investigate the mechanisms responsible for the difference in gas exchange during constant-flow ventilation (CFV) when using gases with different physical properties, we used mixtures of 70% N2-30% O2 (N2-O2) and 70% He-30% O2 (He-O2) as the insufflating gases in 12 dogs. All dogs but one had higher arterial PCO2 (PaCO2) with He-O2 compared with N2-O2. At a flow of 0.37 +/- 0.12 l/s, the mean PaCO2's with N2-O2 and He-O2 were 41.3 +/- 13.9 and 53.7 +/- 20.3 Torr, respectively (P less than 0.01); at a flow rate of 0.84 +/- 0.17 l/s, the mean PaCO2's were 29.1 +/- 11.3 and 35.3 +/- 13.6 Torr, respectively (P less than 0.01). The chest was then opened to alter the apposition between heart and the lungs, thereby reducing the extent of cardiogenic oscillations by 58.4 +/- 18.4%. This intervention did not significantly alter the difference in PaCO2 between N2-O2 and He-O2 from that observed in the intact animals, although the individual PaCO2 values for each gas mixture did increase. When the PaCO2 was plotted against stagnation pressure (rho V2), the difference in PaCO2 between N2-O2 and He-O2 was nearly abolished in both the closed- and open-chest animals. These findings suggest that the different PaCO2's obtained by insufflating gases with different physical properties at a fixed flow rate, catheter position, and lung volume result mainly from a difference in the properties of the jet.

The Effect of Vocabulary Intervention on Text Comprehension: Who Benefits?

2019 ◽  
Vol 50 (4) ◽  
pp. 562-578 ◽  
Author(s):  
Dawna Duff
Keyword(s):  
Middle School ◽  
Reading Comprehension ◽  
Text Comprehension ◽  
Classroom Instruction ◽  
Vocabulary Instruction ◽  
Clinical Intervention ◽  
Vocabulary Knowledge ◽  
Vocabulary Intervention ◽  
The Mean ◽  
The Difference

Purpose Vocabulary intervention can improve comprehension of texts containing taught words, but it is unclear if all middle school readers get this benefit. This study tests 2 hypotheses about variables that predict response to vocabulary treatment on text comprehension: gains in vocabulary knowledge due to treatment and pretreatment reading comprehension scores. Method Students in Grade 6 ( N = 23) completed a 5-session intervention based on robust vocabulary instruction (RVI). Knowledge of the semantics of taught words was measured pre- and posttreatment. Participants then read 2 matched texts, 1 containing taught words (treated) and 1 not (untreated). Treated texts and taught word lists were counterbalanced across participants. The difference between text comprehension scores in treated and untreated conditions was taken as a measure of the effect of RVI on text comprehension. Results RVI resulted in significant gains in knowledge of taught words ( d RM = 2.26) and text comprehension ( d RM = 0.31). The extent of gains in vocabulary knowledge after vocabulary treatment did not predict the effect of RVI on comprehension of texts. However, untreated reading comprehension scores moderated the effect of the vocabulary treatment on text comprehension: Lower reading comprehension was associated with greater gains in text comprehension. Readers with comprehension scores below the mean experienced large gains in comprehension, but those with average/above average reading comprehension scores did not. Conclusion Vocabulary instruction had a larger effect on text comprehension for readers in Grade 6 who had lower untreated reading comprehension scores. In contrast, the amount that children learned about taught vocabulary did not predict the effect of vocabulary instruction on text comprehension. This has implications for the identification of 6th-grade students who would benefit from classroom instruction or clinical intervention targeting vocabulary knowledge.

Efficacy and Safety of Oral Ivermectin and Topical Permethrin in the Treatment of Scabies

2020 ◽  
Vol 33 (1) ◽  
pp. 41-47
Author(s):  
Mohsena Akhter ◽  
Ishrat Bhuiyan ◽  
Zulfiqer Hossain Khan ◽  
Mahfuza Akhter ◽  
Gulam Kazem Ali Ahmad ◽  
...  
Keyword(s):  
Skin Diseases ◽  
Close Contact ◽  
Randomized Study ◽  
Sarcoptes Scabiei ◽  
Efficacy And Safety ◽  
Common Skin ◽  
Group A ◽  
The Mean ◽  
The Difference ◽  
Group B

Background: Scabies is one of the most common skin diseases in our country. It is caused by the mite Sarcoptes scabiei var hominis, which is an ecto-parasite infesting the epidermis. Scabies is highly contagious. Prevalence is high in congested or densely populated areas. Individuals with close contact with an affected person should be treated with scabicidal which is available in both oral and topical formulations. The only oral but highly effective scabicidal known to date is Ivermectin. Amongst topical preparations, Permethrin 5 % cream is the treatment of choice. Objective: To evaluate the efficacy & safety of oral Ivermectin compared to topical Permethrin in the treatment of scabies. Methodology: This prospective, non-randomized study was conducted at the out-patient department of Dermatology and Venereology of Shaheed Suhrawardy Medical College & Hospital over a period of 6 months, from August 2016 to January 2017. The study population consisted of one hundred patients having scabies, enrolled according to inclusion criteria. They were divided into two groups. group A was subjected to oral Ivermectin and the group B to Permethrin 5% cream. Patients were followed up on day 7 and 14 for assessment of efficacy and safety. Result: The mean scoring with SD in group A (Ivermectin) and group B (Permethrin) were 8.26 ± 2.22 and 7.59 ± 2.01 respectively at the time of observation. The difference between the mean score of the two group is not significant (p=0.117) the mean scoring with SD in group A and group B were 4.54 ± 2.05 and 1.64 ± 1.84 respectively at 7thdays. The difference between the mean score of the two group is significant (p<0.001). The mean scoring with SD in group A and group B were 2.68± 2.35 and .36± 1.10 respectively at 14th day difference between the mean score of the group is significant (p<0.001). Conclusion: Topical application of permethrin 5% cream is more effective and safer than oral Ivermectin in the treatment of scabies. TAJ 2020; 33(1): 41-47

EFFECTS OF SYNTHETIC LH/FSH-RELEASING HORMONE (LRH) ON PLASMA LH AND FSH IN AMENORRHOEIC WOMEN

1974 ◽  
Vol 75 (4) ◽  
pp. 647-652 ◽  
Author(s):  
G. Rannevik ◽  
J. Thorell
Keyword(s):  
Urinary Excretion ◽  
Initial Response ◽  
Releasing Hormone ◽  
The Mean ◽  
The Difference ◽  
Serial Measurements

ABSTRACT Eight amenorrhoeic women were given 100 μg synthetic LRH (Hoechst) iv and im, respectively, at an interval of 2 weeks. Four of the women received the iv injection first and four the im injection. The urinary excretion of oestrogens and pregnanediol was low and unaltered throughout the test weeks. The effects of LRH were compared by serial measurements of the plasma LH and FSH during 8 h. The initial response of LH for up to 25 min and that of FSH for up to 60 min were equal whether LRH was given iv or im. The difference appeared later. Four hours after the injection the mean increase of LH to iv injection was 0.5 ng/ml (N. S.), while that to im injection was 1.9 ng/ml (P < 0.01). The corresponding values for FSH were 1.3 (P < 0.05) and 3.2 (P < 0.001). The effect of LRH administration im was thus found to be larger and more prolonged.

Development of Prolonged Delivery of Tramadol and Dissolution Translation by Statistical Data Treatment

2011 ◽  
Vol 4 (1) ◽  
pp. 1331-1337
Author(s):  
P B Parejiya ◽  
B S Barot ◽  
P K Shelat
Keyword(s):  
Drug Release ◽  
Study Data ◽  
Stability Study ◽  
Dissolution Time ◽  
Matrix Tablet ◽  
Burst Effect ◽  
The Matrix ◽  
The Mean ◽  
The Difference ◽  
Dissolution Efficiency

The present study was carried out to fabricate a prolonged design for tramadol using Kollidon SR (Polyvinyl acetate and povidone based matrix retarding polymer). Matrix tablet formulations were prepared by direct compression of Kollidon SR of a varying proportion with a fixed percentage of tramadol. Tablets containing a 1:0.5 (Drug: Kollidon SR) ratio exhibited a rapid rate of drug release with an initial burst effect. Incorporation of more Kollidon SR in the matrix tablet extended the release of drug with subsequent minimization of the burst effect as confirmed by the mean dissolution time, dissolution efficiency and f2 value. Among the formulation batches, a direct relationship was obtained between release rate and the percentage of Kollidon SR used. The formulation showed close resemblance to the commercial product Contramal and compliance with USP specification. The results were explored and explained by the difference of micromeritic characteristics of the polymers and blend of drug with excipients. Insignificant effects of various factors, e.g. pH of dissolution media, ionic strength, speed of paddle were found on the drug release from Kollidon-SR matrix. The formulation followed the Higuchi kinetic model of drug release. Stability study data indicated stable character of Batch T6 after short-term stability study.

Seasonal trends in the stable isotopic composition of snow and meltwater runoff in a subarctic catchment at Okstindan, Norway

2004 ◽  
Vol 35 (2) ◽  
pp. 119-137 ◽  
Author(s):  
S.D. Gurney ◽  
D.S.L. Lawrence
Keyword(s):  
Isotopic Composition ◽  
Mean Value ◽  
Mean Values ◽  
Stable Isotopic Composition ◽  
Meltwater Runoff ◽  
Stable Isotopic ◽  
The Mean ◽  
The Difference ◽  
Δ18o And Δd

Seasonal variations in the stable isotopic composition of snow and meltwater were investigated in a sub-arctic, mountainous, but non-glacial, catchment at Okstindan in northern Norway based on analyses of δ18O and δD. Samples were collected during four field periods (August 1998; April 1999; June 1999 and August 1999) at three sites lying on an altitudinal transect (740–970 m a.s.l.). Snowpack data display an increase in the mean values of δ18O (increasing from a mean value of −13.51 to −11.49‰ between April and August), as well as a decrease in variability through the melt period. Comparison with a regional meteoric water line indicates that the slope of the δ18O–δD line for the snowpacks decreases over the same period, dropping from 7.49 to approximately 6.2.This change points to the role of evaporation in snowpack ablation and is confirmed by the vertical profile of deuterium excess. Snowpack seepage data, although limited, also suggest reduced values of δD, as might be associated with local evaporation during meltwater generation. In general, meltwaters were depleted in δ18O relative to the source snowpack at the peak of the melt (June), but later in the year (August) the difference between the two was not statistically significant. The diurnal pattern of isotopic composition indicates that the most depleted meltwaters coincide with the peak in temperature and, hence, meltwater production.

Study of pumping effect in flow-through electrolysers

1983 ◽  
Vol 48 (8) ◽  
pp. 2232-2248 ◽  
Author(s):  
Ivo Roušar ◽  
Michal Provazník ◽  
Pavel Stuhl
Keyword(s):  
Natural Convection ◽  
Balance Equation ◽  
Volume Fraction ◽  
Industrial Applications ◽  
Pumping Effect ◽  
Flow Through ◽  
The Mean ◽  
The Difference

In electrolysers with recirculation, where a gas is evolved, the pumping of electrolyte from a lower to a higher level can be effected by natural convection due to the difference between the densities of the inlet electrolyte and the gaseous emulsion at the outlet. An accurate balance equation for calculation of the rate of flow of the pumped liquid is derived. An equation for the calculation of the mean volume fraction of bubbles in the space between the electrodes is proposed and verified experimentally on a pilot electrolyser. Two examples of industrial applications are presented.

Propensity-adjusted cost analysis of radial versus femoral access for neuroendovascular procedures

2020 ◽  
pp. neurintsurg-2020-016728
Author(s):  
Joshua S Catapano ◽  
Andrew F Ducruet ◽  
Stefan W Koester ◽  
Tyler S Cole ◽  
Jacob F Baranoski ◽  
...  
Keyword(s):  
Hospital Stay ◽  
Hospital Costs ◽  
Length Of Hospital Stay ◽  
Diagnostic Procedures ◽  
Femoral Access ◽  
Catheter Size ◽  
The Mean ◽  
The Difference ◽  
Procedure Type ◽  
Angiographic Findings

BackgroundTransradial artery (TRA) access for neuroendovascular procedures is associated with fewer complications than transfemoral artery (TFA) access. This study compares hospital costs associated with TRA access to those associated with TFA access for neurointerventions.MethodsElective neuroendovascular procedures at a single center were retrospectively analyzed from October 1, 2018 to May 31, 2019. Hospital costs for each procedure were obtained from the hospital financial department. The primary outcome was the difference in the mean hospital costs after propensity adjustment between patients who underwent TRA compared with TFA access.ResultsOf the 338 elective procedures included, 63 (19%) were performed through TRA versus 275 (81%) through TFA access. Diagnostic procedures were more common in the TRA cohort (51 of 63, 81%) compared with the TFA cohort (197 of 275, 72%), but the difference was not significant (p=0.48). The TRA cohort had a shorter length of hospital stay (mean (SD) 0.3 (0.5) days) compared with the TFA cohort (mean 0.7 (1.3) days; p=0.02) and lower hospital costs (mean $12 968 ($6518) compared with the TFA cohort (mean $17 150 ($10 946); p=0.004). After propensity adjustment for age, sex, symptoms, angiographic findings, procedure type, sheath size, and catheter size, TRA access was associated with a mean hospital cost of $2514 less than that for TFA access (95% CI −$4931 to −$97; p=0.04).ConclusionNeuroendovascular procedures performed through TRA access are associated with lower hospital costs than TFA procedures. The lower cost is likely due to a decreased length of hospital stay for TRA.

Estimating Utility Values for Health States of DFU Patients Using EQ-5D-5L and cTTO

2021 ◽  
pp. 153473462110143
Author(s):  
Morteza Arab-Zozani ◽  
Hossein Safari ◽  
Zoha Dori ◽  
Somayeh Afshari ◽  
Hosein Ameri ◽  
...  
Keyword(s):  
Foot Ulcer ◽  
Diabetic Foot Ulcer ◽  
Economic Modeling ◽  
Health State ◽  
Health States ◽  
Utility Values ◽  
The Mean ◽  
The Difference ◽  
Diabetes Center ◽  
Health State Utility Values

Health-state utility values of diabetic foot ulcer (DFU) patients are necessary for clinical praxis and economic modeling. The purpose of this study was to estimate utility values in DFU patients using the EuroQol-5-dimension-5-level (EQ-5D-5L) and composite time trade-off (cTTO). The EQ-5D-5L and cTTO were used for estimating utility values. Data were collected from 228 patients referred to the largest governmental diabetes center in the South of Iran, Yazd province. When appropriate, independent sample t-test or analysis of variance test was used to test the difference in the utility values in each of the demographic and clinical characteristics of the patients. Finally, the BetaMix was used to identify predictors of the utility values. The means of EQ-5D-5L and cTTO values were 0.55( SD 0.21) and 0.67( SD 0.23), respectively. Anxiety and pain were the most common problems reported by the patients. The difference between the mean EQ-5D-5L values was significant for age, grade of ulcer, number of comorbidities, and having complications. In addition, variables of gender, age, grade of ulcer, and having complications were significant predictors of the EQ-5D-5L. The difference between the mean cTTO values was significant for age, employment status, grade of ulcer, number of comorbidities, and having complications. Moreover, variables of gender, age, grade of ulcer, number of comorbidities, and developing complications were significant predictors of cTTO. The current study provided estimates of utility values for DFU patients for clinical praxis and economic modeling. These estimates, similar to utilities reported in other studies, were low. Identifying strategies to decrease anxiety/depression and pain in patients is important to improve the utility values.

scholarly journals Analysis of National Healthcare Safety Network Clostridioides difficile Infection Standardized Infection Ratio by Test Type

2020 ◽  
Vol 41 (S1) ◽  
pp. s116-s118
Author(s):  
Qunna Li ◽  
Andrea Benin ◽  
Alice Guh ◽  
Margaret A. Dudeck ◽  
Katherine Allen-Bridson ◽  
...  
Keyword(s):  
Risk Adjustment ◽  
Healthcare Facility ◽  
Directional Pattern ◽  
Incidence Rates ◽  
Nucleic Acid Amplification ◽  
Test Type ◽  
Clostridioides Difficile ◽  
Clostridioides Difficile Infection ◽  
The Mean ◽  
The Difference

Background: The NHSN has used positive laboratory tests for surveillance of Clostridioides difficile infection (CDI) LabID events since 2009. Typically, CDIs are detected using enzyme immunoassays (EIAs), nucleic acid amplification tests (NAATs), or various test combinations. The NHSN uses a risk-adjusted, standardized infection ratio (SIR) to assess healthcare facility-onset (HO) CDI. Despite including test type in the risk adjustment, some hospital personnel and other stakeholders are concerned that NAAT use is associated with higher SIRs than are EIAs. To investigate this issue, we analyzed NHSN data from acute-care hospitals for July 1, 2017 through June 30, 2018. Methods: Calendar quarters for which CDI test type was reported as NAAT (includes NAAT, glutamate dehydrogenase (GDH)+NAAT and GDH+EIA followed by NAAT if discrepant) or EIA (includes EIA and GDH+EIA) were selected. HO CDI SIRs were calculated for facility-wide inpatient locations. We conducted the following analyses: (1) Among hospitals that did not switch their test type, we compared the distribution of HO incident rates and SIRs by those reporting NAAT vs EIA. (2) Among hospitals that switched their test type, we selected quarters with a stable switch pattern of 2 consecutive quarters of each of EIA and NAAT (categorized as pattern EIA-to-NAAT or NAAT-to-EIA). Pooled semiannual SIRs for EIA and NAAT were calculated, and a paired t test was used to evaluate the difference of SIRs by switch pattern. Results: Most hospitals did not switch test types (3,242, 89%), and 2,872 (89%) reported sufficient data to calculate SIRs, with 2,444 (85%) using NAAT. The crude pooled HO CDI incidence rates for hospitals using EIA clustered at the lower end of the histogram versus rates for NAAT (Fig. 1). The SIR distributions of both NAAT and EIA overlapped substantially and covered a similar range of SIR values (Fig. 1). Among hospitals with a switch pattern, hospitals were equally likely to have an increase or decrease in their SIR (Fig. 2). The mean SIR difference for the 42 hospitals switching from EIA to NAAT was 0.048 (95% CI, −0.189 to 0.284; P = .688). The mean SIR difference for the 26 hospitals switching from NAAT to EIA was 0.162 (95% CI, −0.048 to 0.371; P = .124). Conclusions: The pattern of SIR distributions of both NAAT and EIA substantiate the soundness of NHSN risk adjustment for CDI test types. Switching test type did not produce a consistent directional pattern in SIR that was statistically significant.Disclosures: NoneFunding: None

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