scholarly journals SYSVENT: Prova de Conceito de um Protótipo para Ventilar Doentes em Cuidados Intensivos

2020 ◽  
Vol 33 (13) ◽  
Author(s):  
Nuno Cortesão ◽  
Marco Fernandes ◽  
Danielson Pina ◽  
Felipe Fernandes ◽  
José Vale Machado ◽  
...  
Keyword(s):  
Intensive Care ◽  
Tidal Volume ◽  
Mean Value ◽  
Artificial Lung ◽  
Inspiratory Pressure ◽  
Prototype Model ◽  
Positive End Expiratory Pressure ◽  
The Mean ◽  
Set Up ◽  
Accuracy Performance

Introduction: The new coronavirus pandemic has led to scarcity of invasive ventilation resources in hospitals in several countries. In this context, the Portuguese Medical Association invited intensive care physicians who, in collaboration with SYSADVANCE S.A., developed SYSVENT OM1, a ventilator capable of operating in controlled and assisted modes (volume and pressure) and able to treat patients admitted to intensive care units. In this study we do the proof of concept comparing programmed tidal volume, inspiratory pressure and positive end-expiratory pressure with those measured by the ventilator and an external measuring equipment.Material and Methods: We set up the ventilator in tandem with an artificial lung and a flow analyzer. We measured expiratory tidal volume, and inspiratory pressure against three levels of compliance, each with six steps of tidal volume. Positive end-expiratory pressure was measured at 2 cmH2O incremental along eight steps. For each measurement, we performed three readings.Results: Considering each of the three single variables, the mean value of the highest difference between programmed values andmeasured values is, for all of them, within what we considered to be acceptable for a prototype model (tidal volume = -28.1 mL, inspiratory pressure = 0.8 cmH2O and positive end-expiratory pressure = -1.1 cmH2O). This difference is greater when evaluated with the external measuring equipment in comparison with the ventilator.Discussion: The results showed a good monitoring and accuracy performance. Technical limitations related with the artificial lung and the flow analyzer have been documented, which do not compromise the results, but limit their amplitude.Conclusion: For tested parameters, the ventilator has a good operating performance, is in accordance with the initial premises and has potential for clinical use.

scholarly journals Prophylactic Positive End-Expiratory Pressure and Postintubation Hemodynamics: An Interventional, Randomized Study

2010 ◽  
Vol 17 (3) ◽  
pp. e45-e50 ◽  
Author(s):  
Olivier Lesur ◽  
Marie-Anaïs Remillard ◽  
Catherine St-Pierre ◽  
Simon Falardeau
Keyword(s):  
Intensive Care ◽  
Randomized Study ◽  
Final Analysis ◽  
Study Cohort ◽  
Emergency Setting ◽  
Positive End Expiratory Pressure ◽  
Medical Intensive Care ◽  
The Mean ◽  
The Difference ◽  
Present Trial

OBJECTIVE: To investigate the hemodynamic and outcome effects of implementing prophylactic positive end-expiratory pressure (PEEP) versus zero end-expiratory pressure (ZEEP) in patients during the postintubation period in the emergency setting.METHODS: The present study was a prospective, single-centre, interventional, single-blinded randomized trial performed in a 16-bed medical intensive care unit. The study cohort consisted of consecutive patients who urgently required intubation. During the postintubation period, patients received either 5 cmH2O PEEP or ZEEP. The primary aim was to assess the variation in mean arterial pressure (MAP) from baseline up to 90 min postintubation. The secondary aim was to determine the mean duration of intubation, level of MAP support after intubation and 28-day mortality.RESULTS: Seventy-five consecutive patients with similar mean (± SD) baseline characteristics and preintubation MAP (76±18 mmHg in the ZEEP group and 78.5±23 mmHg in the PEEP group, P=Not significant [NS]) were studied. The final analysis was performed in 33 patients in the ZEEP group and 30 patients in the PEEP group. Regarding outcome measures following intubation, delta MAP (ie, the difference between the lowest MAP values from baseline) was not differentially affected in either group (P=NS); the mean durations of intubation were similar (ZEEP 9.2±8.5 days versus PEEP 9.2±8.8 days, P=NS); 28-day mortality was not discriminative (ZEEP 14 of 33, PEEP nine of 30; P=NS); and levels of MAP support after intubation were comparable between the two groups.CONCLUSION: In the present trial, there was no evidence that implementing a prophylactic PEEP of 5 cmH2O adversely affects short-term hemodynamics or outcome in medical intensive care patients during the postintubation period.

Effect of lung volume on interrupter resistance in cats challenged with methacholine

1988 ◽  
Vol 64 (1) ◽  
pp. 360-366 ◽  
Author(s):  
P. D. Sly ◽  
K. A. Brown ◽  
J. H. Bates ◽  
P. T. Macklem ◽  
J. Milic-Emili ◽  
...  
Keyword(s):  
Respiratory System ◽  
Lung Volume ◽  
Mean Value ◽  
Positive End Expiratory Pressure ◽  
Response Curves ◽  
Residual Capacity ◽  
Respiratory System Resistance ◽  
The Mean ◽  
Pressure Changes ◽  
Induced Changes

To examine the effects of changes in lung volume on the magnitude of maximal bronchoconstriction, seven anesthetized, paralyzed, tracheostomized cats were challenged with aerosolized methacholine (MCh) and respiratory system resistance (Rss) was measured at different lung volumes using the interrupter technique. Analysis of the pressure changes following end-inspiratory interruptions allowed us to partition Rss into two quantities with the units of resistance, one (Rinit) corresponding to the resistance of the airways and the other (Rdif) reflecting the viscoelastic properties of the tissues of the respiratory system as well as gas redistribution following interruption of flow. Rinit and Rdif were used to construct concentration-response curves to MCh. Lung volume was increased by the application of 5, 10, and 15 cmH2O of positive end-expiratory pressure. The curve for Rinit reached a plateau in all cats, demonstrating a limit to the degree of MCh-induced bronchoconstriction. The mean value of Rinit (cmH2O.ml-1.s) for the group under control conditions was 0.011 and rose to 0.058 after maximal bronchoconstriction; the volume at which the flow was interrupted was 11.5 +/- 0.5 (SE) ml/kg above functional residual capacity (FRC). It then fell progressively to 0.029 at 21.2 +/- 0.8 ml/kg above FRC, 0.007 at 35.9 +/- 1.3 ml/kg above FRC, and 0.005 at 52.0 +/- 1.8 ml/kg above FRC. Cutting either the sympathetic or parasympathetic branches of the vagi had no significant effect on the lung volume-induced changes in MCh-induced bronchoconstriction.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals The 4-year Experience of Nursing Activities Score Use in a Brazilian Cardiac Intensive Care Unit

2021 ◽  
Vol 9 (5) ◽  
pp. 382-401
Author(s):  
Elias Rodrigues de Almeida Júnior ◽  
Daniel Braga de Oliveira ◽  
Gabriela Rodrigues dos Santos ◽  
Rosângela de Oliveira Felice ◽  
Fabiola Alves Gomes ◽  
...  
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Patient Care ◽  
Service Management ◽  
Mean Value ◽  
Nursing Workload ◽  
Mean Values ◽  
Day Of The Week ◽  
The Mean ◽  
Nursing Professional

The assessment of nursing workload offers both support for patient care planning and service management. In an Intensive Care Unit (ICU) this workload is measured by the Nursing Activities Scores (NAS), although in specialized areas such as Cardiology, its use is still diminished. Objective: To describe NAS and the prevalence of its sub-items in a Brazilian Cardiac ICU. We also aimed to evaluate NAS oscillation since the opening of the unit, and according to the day of the week. Methods: Daily NAS records collected from November 2014 to October 2018 were assessed, totaling 8600 assessments distributed over 49 months. The data were analyzed according to time, day of the week, number of records per day, and dichotomizing if NAS was higher or lower than 50 points. Results: NAS presented mean value of 52.91 points and a median of 53.40 points. The mean NAS values per month ranged from 45.00 to 59.10 points. The percentage of NAS assessments above 50 points ranged from 20.59 to 92.34% per month and proved to be a better indicator for assessing the variability of the monthly workload. When combined two by two, 66.01% of NAS combinations scored more than 100 points, suggesting the need for more than one nursing professional per day. When the data were stratified by year, 2018 had the lowest means compared to the others. When compared to the mean values in function of the day of the week, it was observed that Monday to Friday (with the highest mean on Wednesday, the predominant day for cardiac surgeries) showed higher values than weekends. Conclusions: Overall, NAS showed low values compared to other general or cardiac ICUs, it also presented temporal variability and our results showed risk of workload overload which can compromise patient care and safety. Such results reinforce the importance of the administrative and assistant aspects of the routine use of NAS in ICUs specially in specialized environments as Cardiac ICU.

scholarly journals Changes in selected electrolytes in adult intensive care patients at the University Teaching Hospital, Lusaka, Zambia

2020 ◽  
Vol 4 (1) ◽  
pp. 28-34
Author(s):  
Ninza Sheyo ◽  
◽  
Bellington Vwalika ◽  
John Kinnear ◽  
◽  
...  
Keyword(s):  
Renal Function ◽  
Intensive Care ◽  
Sodium Level ◽  
Mean Value ◽  
University Teaching ◽  
P Value ◽  
The Mean ◽  
The University ◽  
Renal Function Tests ◽  
Sodium And Potassium

Background: The importance of regulating electrolyte levels is well recognized in most Intensive Care Units (ICU). Various institutions across the globe have found varying figures on the extent and causes of electrolytes derangements in ICUs. The extent of electrolyte and fluid imbalance in patients being admitted and already admitted to the Main ICU (MICU) at the University Teaching Hospital (UTH) Lusaka Zambia is unknown. This study aimed to explore the 24hour changes in sodium and potassium in adult MICU patients at the UTH, Lusaka, Zambia. Methods: This was a prospective cohort study of the patients admitted to the MICU at UTH, Lusaka, Zambia. Data was collected over a four-month period (August to November) in 2017. Only consenting patients 18 years and above admitted for at least 24 hours in the unit were enrolled. On admission, routine baseline investigations were obtained from every patient which included a full blood count and renal function tests. The second set of investigations was collected 24 hours post MICU admission. The blood samples were obtained from a peripheral vein in heparinized bottles for renal function tests. Serum electrolyte analysis was done was at UTH. Normal serum concentrations of sodium and potassium were considered as 135-145mmol/l and 3.5 - 4.5mmol/L, respectively. Comparisons between means were done with the Wilcoxon signed-rank test. Logistic regression analysis was used to investigate the relationship between dependent and independent variables. A p-value < 0.05 was considered statistically significant. Statistical analysis was performed with STATA 13 SE. Results: A total number of 100 patients were included in this study with a mean age of 36.8 years (SD = 12.1). The mean value of sodium level was 136.7 (SD = 8.9) mmol/L and 139.0 (SD = 11.6) mmol/L, on admission and 24 hours post-admission respectively. This difference in serum sodium level was shown to be statistically significant with a P-value = 0.0051. Hypernatremia was shown to be associated with an increased risk of death (p = 0.021) in the Unit with an odds ratio of 4.0 at 95% confidence interval of 1.3 to 13.8. Hyponatremia was the most prevalent electrolyte imbalance but was neither shown to be associated with mortality (P-value = 0.18) nor prolonged ICU stay (0.56) at 24 hours post-admission. The mean value of potassium level was 4.2 (SD = 1.1) mmol/L and 4.3 (SD = 1.1), on admission and 24 hours post-admission respectively. This difference was not statistically significant (P-value = 0.57). Conclusion: There was a statistically significant change in serum sodium levels after 24 hours post-admission but there was no statistically significant change in potassium. Hyponatremia was the most prevalent abnormality whilst hypernatremia had a statistically significant association with mortality. Therefore, electrolyte imbalances can occur as early as the first day of admission in ICU with fatal complications. Correcting electrolyte imbalances in MICU patients is an urgent necessity and should not be delayed.

scholarly journals On the normal weston cadmium cell

1907 ◽  
Vol 80 (535) ◽  
pp. 75-76 ◽  
Keyword(s):  
Sulphuric Acid ◽  
Chemical Precipitation ◽  
Mean Value ◽  
Experimental Investigations ◽  
Guiding Principle ◽  
The Past ◽  
Primary Object ◽  
The Mean ◽  
Mercurous Nitrate ◽  
Set Up

The experimental investigations described had as their primary object the improvement of the Clark and cadmium cells as standards of electromotive force. In the past many investigators have pointed out that the mercurous sulphate used as a depolariser may produce variations in the E. M. F. as great as 0·002 volt, and the first thing sought by us was a mode of manufacture of the sulphate which could be relied on to give a constant product. We have prepared the salt in four ways: (1) Electrolytically (the method is due to Carhart and Hulett, and Wolff); (2) by chemical precipitation, mercurous nitrate being added to sulphuric acid; (3) by the recrystallisation of purchased samples of mercurous sulphate from strong sulphuric acid; and (4) by the action of fuming sulphuric acid on mercury. The mean value of the cells set up with the electrolytic salt is 1·01828 volts; with the sulphate prepared by (2) the E. M. F. is 1·01830 volts; (3) gives 1·01832 volts, and (4) gives 1·01831 volts. We conclude that the mode of manufacture of the depolariser is immaterial, provided that certain conditions are observed, and our guiding principle in the manufacture of the salt and the preparation of the paste is to prevent hydrolysis by keeping the salt in contact with dilute sulphuric acid (1 to 6) or with saturated cadmium sulphate solution.

Using Conventional Infant Ventilators at Unconventional Rates

PEDIATRICS ◽  
1984 ◽  
Vol 74 (4) ◽  
pp. 487-492 ◽  
Author(s):  
Stephen J. Boros ◽  
Dennis R. Bing ◽  
Mark C. Mammel ◽  
Erik Hagen ◽  
Margaret J. Gordon
Keyword(s):  
Tidal Volume ◽  
Airway Pressure ◽  
Important Determinant ◽  
Peak Inspiratory Pressure ◽  
Lung Compliance ◽  
Minute Volume ◽  
Inspiratory Pressure ◽  
Positive End Expiratory Pressure ◽  
Inspiratory Time ◽  
Pressure Monitor

The effect of progressive increases in ventilator rate on delivered tidal and minute volumes, and the effect of changing peak inspiratory pressure (Pmax), positive end-expiratory pressure (PEEP), and inspiration to expiration (I:E) ratio at different ventilator rates were examined. Five different continuous-flow, time-cycled, pressure-preset infant ventilators were studied using a pneumotachograph, an airway pressure monitor, and a lung simulator. As rates increased from 10 to 150 breaths per minute, tidal volume stayed constant until 25 to 30 breaths per minute; then progessively decreased. In all, tidal volume began to decrease when proximal airway pressure waves lost inspiratory pressure plateaus. As rates increased, minute volume increased until 75 breaths per minute, then leveled off, then decreased. Substituting helium for O2 increased the ventilator rate at which this minute volume plateau effect occurred. Increasing peak inspiratory pressure consistently increased tidal volume. Increasing positive end-expiratory pressure decreased tidal volume. At rates less than 75 breaths per minute, inspiratory time (inspiration to expiration ratio) had little effect on delivered volume. At rates greater than 75 breaths per minute, inspiratory time became an important determinant of minute volume. For any given combination of lung compliance and airway resistance: (1) there is a maximum ventilator rate beyond which tidal volume progressively decreases and another maximum ventilator rate beyond which minute volume progressively decreases; (2) at slower rates, delivered volumes are determined primarily by changes in proximal airway pressures; (3) at very rapid rates, inspiratory time becomes a key determinant of delivered volume.

scholarly journals Impact of the Anesthetic Conserving Device on Respiratory Parameters and Work of Breathing in Critically Ill Patients under Light Sedation with Sevoflurane

2014 ◽  
Vol 121 (4) ◽  
pp. 808-816 ◽  
Author(s):  
Russell Chabanne ◽  
Sebastien Perbet ◽  
Emmanuel Futier ◽  
Nordine Ait Ben Said ◽  
Samir Jaber ◽  
...  
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Work Of Breathing ◽  
Inspiratory Pressure ◽  
Heated Humidifier ◽  
Intravenous Sedation ◽  
Positive End Expiratory Pressure ◽  
Respiratory Parameters ◽  
Ventilatory Parameters ◽  
Light Sedation

Abstract Background: Sevoflurane sedation in the intensive care unit is possible with a special heat and moisture exchanger called the Anesthetic Conserving Device (ACD) (AnaConDa®; Sedana Medical AB, Uppsala, Sweden). The ACD, however, may corrupt ventilatory mechanics when used during the weaning process of intensive care unit patients. The authors compared the ventilatory effects of light-sedation with sevoflurane administered with the ACD and those of classic management, consisting of a heated humidifier and intravenous sedation, in intensive care unit patients receiving pressure-support ventilation. Methods: Fifteen intensive care unit patients without chronic pulmonary disease were included. A target Richmond Agitation Sedation Scale level of −1/−2 was obtained with intravenous remifentanil (baseline 1-condition). Two successive interventions were tested: replacement of the heated humidifier by the ACD without sedation change (ACD-condition) and sevoflurane with the ACD with an identical target level (ACD-sevoflurane-condition). Patients finally returned to baseline (baseline 2-condition). Work of breathing, ventilatory patterns, blood gases, and tolerance were recorded. A steady state of 30 min was achieved for each experimental condition. Results: ACD alone worsened ventilatory parameters, with significant increases in work of breathing (from 1.7 ± 1.1 to 2.3 ± 1.2 J/l), minute ventilation, P0,1, intrinsic positive end-expiratory pressure (from 1.3 ± 2.6 to 4.7 ± 4.2 cm H2O), inspiratory pressure swings, and decreased patient comfort. Sevoflurane normalized work of breathing (from 2.3 ± 1.2 to 1.8 ± 1 J/l), intrinsic positive end-expiratory pressure (from 4.7 ± 4.2 to 1.8 ± 2 cm H2O), inspiratory pressure swings, other ventilatory parameters, and patient tolerance. Conclusions: ACD increases work of breathing and worsens ventilatory parameters. Sevoflurane use via the ACD (for a light-sedation target) normalizes respiratory parameters. In this patient’s population, light-sedation with sevoflurane and the ACD may be possible during the weaning process.

Long-period modulated superstructures in Pd-12.5 at.%Ce and Pd-15 at.%Ce alloys

1990 ◽  
Vol 48 (4) ◽  
pp. 164-165
Author(s):  
Noriyuki Kuwano ◽  
Masaru Itakura ◽  
Kensuke Oki
Keyword(s):  
Electron Microscopy ◽  
Mean Value ◽  
Heavy Elements ◽  
Arc Furnace ◽  
X Ray ◽  
Long Period ◽  
Ultra High Purity ◽  
Heat Treated ◽  
Atomic Scattering ◽  
The Mean

Pd-Ce alloys exhibit various anomalies in physical properties due to mixed valences of Ce, and the anomalies are thought to be strongly related with the crystal structures. Since Pd and Ce are both heavy elements, relative magnitudes of (fcc-fpd) are so small compared with <f> that superlattice reflections, even if any, sometimes cannot be detected in conventional x-ray powder patterns, where fee and fpd are atomic scattering factors of Ce and Pd, and <f> the mean value in the crystal. However, superlattices in Pd-Ce alloys can be analyzed by electron microscopy, thanks to the high detectability of electron diffraction. In this work, we investigated modulated superstructures in alloys with 12.5 and 15.0 at.%Ce.Ingots of Pd-Ce alloys were prepared in an arc furnace under atmosphere of ultra high purity argon. The disc specimens cut out from the ingots were heat-treated in vacuum and electrothinned to electron transparency by a jet method.

Partition Coefficient Ratios and Tumour Perfusion Studied with 85mKr and 133Xe

1987 ◽  
Vol 26 (06) ◽  
pp. 253-257
Author(s):  
M. Mäntylä ◽  
J. Perkkiö ◽  
J. Heikkonen
Keyword(s):  
Partition Coefficient ◽  
Partition Coefficients ◽  
Regional Blood Flow ◽  
Blood Perfusion ◽  
Compartmental Analysis ◽  
Malignant Tumour ◽  
Mean Value ◽  
Perfusion Rate ◽  
Biological Variables ◽  
The Mean

The relative partition coefficients of krypton and xenon, and the regional blood flow in 27 superficial malignant tumour nodules in 22 patients with diagnosed tumours were measured using the 85mKr- and 133Xe-clearance method. In order to minimize the effect of biological variables on the measurements the radionuclides were injected simultaneously into the tumour. The distribution of the radiotracers was assumed to be in equilibrium at the beginning of the experiment. The blood perfusion was calculated by fitting a two-exponential function to the measuring points. The mean value of the perfusion rate calculated from the xenon results was 13 ± 10 ml/(100 g-min) [range 3 to 38 ml/(100 g-min)] and from the krypton results 19 ± 11 ml/(100 g-min) [range 5 to 45 ml/(100 g-min)]. These values were obtained, if the partition coefficients are equal to one. The equations obtained by using compartmental analysis were used for the calculation of the relative partition coefficient of krypton and xenon. The partition coefficient of krypton was found to be slightly smaller than that of xenon, which may be due to its smaller molecular weight.

Detection of Soluble Fibrin Monomer Complexes in Blood by Means of Protamine Sulphate Test

1968 ◽  
Vol 20 (01/02) ◽  
pp. 044-049 ◽  
Author(s):  
B Lipiński ◽  
K Worowski
Keyword(s):  
Human Subjects ◽  
Coronary Thrombosis ◽  
Mean Value ◽  
Healthy Human ◽  
Protamine Sulphate ◽  
Soluble Fibrin ◽  
Fibrin Monomer ◽  
Dog Plasma ◽  
The Mean ◽  
Precipitable Protein

SummaryIn the present paper described is a simple test for detecting soluble fibrin monomer complexes (SFMC) in blood. The test consists in mixing 1% protamine sulphate with diluted oxalated plasma or serum and reading the optical density at 6190 Å. In experiments with dog plasma, enriched with soluble fibrin complexes, it was shown that OD read in PS test is proportional to the amount of fibrin recovered from the precipitate. It was found that SFMC level in plasma increases in rabbits infused intravenously with thrombin and decreases after injection of plasmin with streptokinase. In both cases PS precipitable protein in serum is elevated indicating enhanced fibrinolysis. In healthy human subjects the mean value of OD readings in plasma and sera were found to be 0.30 and 0.11, while in patients with coronary thrombosis they are 0.64 and 0.05 respectively. The origin of SFMC in circulation under physiological and pathological conditions is discussed.

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