Delivery of Positive End-Expiratory Pressure Using Self-Inflating Bags during Newborn Resuscitation Is Possible Despite Mask Leak

Neonatology ◽  
2020 ◽  
Vol 117 (3) ◽  
pp. 341-348 ◽  
Author(s):  
Øystein Herwig Gomo ◽  
Joar Eilevstjønn ◽  
Kari Holte ◽  
Anita Yeconia ◽  
Hussein Kidanto ◽  
...  
Keyword(s):  
Gas Flow ◽  
Ventilation Rate ◽  
Positive End Expiratory Pressure ◽  
Helping Babies Breathe ◽  
Rural Tanzania ◽  
Residual Capacity ◽  
Near Term ◽  
Lung Liquid ◽  
Bag Mask Ventilation ◽  
Ventilation Rates

<b><i>Background:</i></b> Ventilation is the key intervention to resuscitate non-breathing newborns. Positive end-expiratory pressure (PEEP) may facilitate lung-liquid clearance and help establish functional residual capacity. <b><i>Objectives:</i></b> The aim of this study was to describe how mask leak and ventilation rates affect delivered PEEP and tidal volumes during newborn resuscitations using a self-inflating bag with an integrated PEEP valve. <b><i>Methods:</i></b> This was an observational study including near-term/term newborns who received bag-mask ventilation (BMV) with a new self-inflating bag with a novel 6 mbar PEEP valve, without external gas flow, between October 1, 2016 and June 30, 2018 in rural Tanzania. Helping Babies Breathe-trained midwives performed most of the resuscitations. Pressures and flow were continuously measured and recorded by resuscitation monitors. <b><i>Results:</i></b> In total, 198 newborns with a median gestation of 39 weeks (25th, 75th percentiles 37, 40) and birth weight of 3,100 g (2,580, 3,500) were included. The median delivered PEEP and expired (tidal) volume at different levels of mask leak were 6.0 mbar and 11.3 mL/kg at 0–20% mask leak, 5.5 mbar and 9.3 mL/kg at 20–40%, 5.2 mbar and 7.8 mL/kg at 40–60%, 4.6 mbar and 5.0 mL/kg at 60–80%, and 1.0 mbar and 0.6 mL/kg at 80–100% mask leak. A high ventilation rate (&#x3e;60/min) nearly halved expired volumes compared to &#x3c;60/min for 0–60% leak. The BMV rate had a negligible effect on peak inflation pressure (PIP) and PEEP. <b><i>Conclusions:</i></b> Mask leak up to 80% did not impair the provision of recommended PEEP or tidal volumes during BMV with a self-inflating bag. High or low ventilation rates did not significantly affect PIP or PEEP. Expired volumes were reduced at ventilation rates &#x3e;60/min.

Animal Experiments on the Effects of PEEP and Different Ventilation-Compression Ratios in Neonatal Cardiopulmonary Resuscitation

1985 ◽  
Vol 1 (S1) ◽  
pp. 214-215
Author(s):  
W. F. Dick ◽  
E. Traub ◽  
K. Engels ◽  
K. -H. Lindner
Keyword(s):  
Body Weight ◽  
Cardiac Arrest ◽  
Artificial Ventilation ◽  
Animal Experiments ◽  
Ventilation Rate ◽  
Positive End Expiratory Pressure ◽  
Cardiac Compression ◽  
Ventilation Rates ◽  
Average Body ◽  
Average Body Weight

The physiological range of respiratory rates and heart rates in neonates is approximately 40 per min and 120 per min, respectively, which yields a theoretical ventilation-compression ratio of 1:3ratherthan 1:5.Thirty-six anesthetized pigs with an average body weight of 4–5 kg were used in the study. After establishing a steady state by artificial ventilation with 100% oxygen, a cardiac arrest was induced by an intravenous injection of potassium chloride. Following the cardiac arrest, the animals were resuscitated with ventilation rates of 30 and 40 per min, respectively, while external cardiac compression was performed at rates between 60 and 160 per min. Randomly selected animals were resuscitated with ventilation-compression ratios of 1:2, 1:3 and 1:4 for 10 min each, 6 animals each were ventilated using a ventilation rate of 30 per min, 40 per min, or positive end-expiratory pressure.

Inspiration regulates the rate and temporal pattern of lung liquid clearance and lung aeration at birth

2009 ◽  
Vol 106 (6) ◽  
pp. 1888-1895 ◽  
Author(s):  
Melissa L. Siew ◽  
Megan J. Wallace ◽  
Marcus J. Kitchen ◽  
Robert A. Lewis ◽  
Andreas Fouras ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Cesarean Section ◽  
Temporal Pattern ◽  
Phase Contrast ◽  
X Ray ◽  
Lung Aeration ◽  
X Ray Imaging ◽  
Residual Capacity ◽  
Near Term ◽  
Lung Liquid

At birth, the initiation of pulmonary gas exchange is dependent on air entry into the lungs, and recent evidence indicates that pressures generated by inspiration may be involved. We have used simultaneous plethysmography and phase-contrast X-ray imaging to investigate the contribution of inspiration and expiratory braking maneuvers (EBMs) to lung aeration and the formation of a functional residual capacity (FRC) after birth. Near-term rabbit pups ( n = 26) were delivered by cesarean section, placed in a water plethysmograph, and imaged during the initiation of spontaneous breathing. Breath-by-breath changes in lung gas volumes were measured using plethysmography and visualized using phase-contrast X-ray imaging. Pups rapidly (1–5 breaths) generate a FRC (16.2 ± 1.2 ml/kg) by inhaling a greater volume than they expire (by 2.9 ± 0.4 ml·kg−1·breath−1 over the first 5 breaths). As a result, 94.8 ± 1.4% of lung aeration occurred during inspiration over multiple breaths. The incidence of EBMs was rare early during lung aeration, with most (>80%) occurring after >80% of max FRC was achieved. Although EBMs were associated with an overall increase in FRC, 34.8 ± 5.3% of EBMs were associated with a decrease in FRC. We conclude that lung aeration is predominantly achieved by inspiratory efforts and that EBMs help to maintain FRC following its formation.

scholarly journals Proposing Alternative Solutions to Enhance Natural Ventilation Rates in Residential Buildings in the Cfa Climate Zone of Rasht

2021 ◽  
Vol 13 (2) ◽  
pp. 679
Author(s):  
Roya Aeinehvand ◽  
Amiraslan Darvish ◽  
Abdollah Baghaei Daemei ◽  
Shima Barati ◽  
Asma Jamali ◽  
...  
Keyword(s):  
Natural Ventilation ◽  
Residential Buildings ◽  
Residential Building ◽  
Ventilation Rate ◽  
Humid Climate ◽  
The Sustainable Development ◽  
Passive Strategies ◽  
Development Goals ◽  
Ventilation Rates ◽  
Ventilation Systems

Today, renewable resources and the crucial role of passive strategies in energy efficiency in the building sector toward the sustainable development goals are more indispensable than ever. Natural ventilation has traditionally been considered as one of the most fundamental techniques to decrease energy usage by building dwellers and designers. The main purpose of the present study is to enhance the natural ventilation rates in an existing six-story residential building situated in the humid climate of Rasht during the summertime. On this basis, two types of ventilation systems, the Double-Skin Facade Twin Face System (DSF-TFS) and Single-Sided Wind Tower (SSWT), were simulated through DesignBuilder version 4.5. Then, two types of additional ventilation systems were proposed in order to accelerate the airflow, including four-sided as well as multi-opening wind towers. The wind foldable directions were at about 45 degrees (northwest to southeast). The simulation results show that SSWT could have a better performance than the aforementioned systems by about 38%. Therefore, the multi-opening system was able to enhance the ventilation rate by approximately 10% during the summertime.

Canine thoracic electrical impedance with changes in pulmonary gas and blood volumes

1982 ◽  
Vol 53 (6) ◽  
pp. 1608-1613
Author(s):  
R. M. Smith ◽  
B. A. Gray
Keyword(s):  
Chest Wall ◽  
Blood Volume ◽  
Vena Cava ◽  
Systemic Circulation ◽  
Aortic Pressure ◽  
Right Atrial ◽  
Liquid Content ◽  
Primary Determinant ◽  
Residual Capacity ◽  
Lung Liquid

The purpose of this study was to evaluate transthoracic impedance (Z) as an index of total lung liquid content at constant lung gas volume (LGV). To this end we produced rapid changes in pulmonary blood volume (PBV) in anesthetized, paralyzed, closed-chest dogs with the airway occluded at functional residual capacity. Changes in PBV produced by inflation of balloons on catheters positioned in the left atrium (LA) or inferior vena cava (IVC) were estimated from the changes in chest wall recoil pressure, using the chest wall as a plethysmograph after calibration with changes in LGV. Whereas Z increased linearly with decreases in PBV (1–6 ml/kg) produced by the IVC balloon (% delta Z/delta PBV = -0.43 ml/kg, r = -0.81), Z did not change significantly with increases in PBV (1–6 ml/kg) produced by the LA balloon. These observations indicate that changes in PBV are not the primary determinant of changes in Z and raise the possibility that other hemodynamic events are more important. Whereas aortic pressure decreased with both IVC and LA balloon inflations, right atrial pressure (Pra) increased with mitral valve obstruction and decreased with IVC obstruction. Changes in chest wall blood volume in response to changes in Pra could explain the changes in thoracic impedance. Thus, even at constant LGV, events in the systemic circulation appear to invalidate Z as an indicator of lung liquid content.

Abstract 264: Automatic Detection of Ventilations Using the Thoracic Impedance Signal During Lucas Chest Compressions

Circulation ◽  
2019 ◽  
Vol 140 (Suppl_2) ◽  
Author(s):  
Xabier Jaureguibeitia ◽  
Unai Irusta ◽  
Elisabete Aramendi ◽  
Pamela Owens ◽  
Henry E Wang ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Minute Ventilation ◽  
Lung Ventilation ◽  
Detection Algorithm ◽  
Ventilation Rate ◽  
Thoracic Impedance ◽  
Chest Compressions ◽  
Signal Processing Algorithm ◽  
Ventilation Rates ◽  
Mechanical Cpr

Introduction: Resuscitation from out-of-cardiac arrest (OHCA) requires control of both chest compressions and lung ventilation. There are few effective methods for detecting ventilations during cardiopulmonary resuscitation. Thoracic impedance (TI) is sensitive to changes in lung air volumes and may allow detection of ventilations but has not been tested with concurrent mechanical chest compressions. Hypothesis: It is possible to automatically detect and characterize ventilations from TI changes during mechanical chest compressions. Methods: A cohort of 420 OHCA cases (27 survivors to hospital discharge) were enrolled in the Dallas-Fort Worth Center for Resuscitation Research cardiac arrest registry. These patients were treated with the LUCAS-2 CPR device and had concurrent TI and capnogram recordings from MRx (Philips, Andover, MA) monitor-defibrillators. We developed a signal processing algorithm to suppress chest compression artifacts from the TI signal, allowing identification of ventilations. We used the capnogram as gold standard for delivered ventilations. We determined the accuracy of the algorithm for detecting capnogram-indicated ventilations, calculating sensitivity, the proportion of true ventilations detected in the TI, and positive predictive value (PPV), the proportion of true ventilations within the detections. We calculated per minute ventilation rate and mean TI amplitude, as surrogate for tidal volume. Statistical differences between survivors and non-survivors were assessed using the Mann-Whitney test. Results: We studied 4331 minutes of TI during CPR. There were a median of 10 (IQR 6-14) ventilations per min and 52 (30-81) ventilations per patient. Sensitivity of TI was 95.9% (95% CI, 74.5-100), and PPV was 95.8% (95% CI, 80.0-100). The median ventilation rates for survivors and non-survivors were 7.75 (5.37-9.91) min -1 and 5.64 (4.46-7.15) min -1 (p<10 -3 ), and the median TI amplitudes were 1.33 (1.03-1.75) Ω and 1.14 (0.77-1.66) Ω (p=0.095). Conclusions: An accurate automatic TI ventilation detection algorithm was demonstrated during mechanical CPR. The relation between ventilation rate during mechanical CPR and survival was significant, but it was not for impedance amplitude.

Abstract P101: Comparison of Ventilation Rate Measured with Thoracic Bioimpedance and with Capnography during Out-of-Hospital Cardiopulmonary Resuscitation

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Ahamed H Idris ◽  
Sarah Beadle ◽  
Mohamud Daya ◽  
Dana Zive
Keyword(s):  
Cardiac Arrest ◽  
Ventilation Rate ◽  
Rater Agreement ◽  
Chest Compressions ◽  
Intra Class Correlation ◽  
Automated Software ◽  
Ventilation Rates ◽  
Patient File ◽  
Hospital Cardiac Arrest ◽  
Manual Review

Objective: To determine the ability of thoracic bioimpedance to measure ventilation rate during cardiac arrest and CPR. Methods: Philips MRx devices monitored 32 patients during out-of-hospital cardiac arrest and CPR. The devices recorded chest compressions with an accelerometer, continuous 1-lead EKG, thoracic bioimpedance, and continuous capnography. Of the 32 files, 4 were not used in this study because of incomplete recording. Two reviewers manually annotated ventilation waveforms independently using Laerdal QCPR software, which also automatically annotated ventilation through the bioimpedance channel. Reviewers manually measured ventilation rate (number of breaths/min) recorded with capnography for each 1 minute epoch, which were matched and compared with those measured through bioimpedance for each patient file (N = 28). A total of 585 1-minute epochs were measured and compared. We assessed intra-class correlation for 2 individual raters for ventilation rates measured with capnography and with annotated bioimpedance to establish inter-user reliability of measurements. Ventilation rate measured with capnography vs. bioimpedance was compared with simple regression. Results: The majority (60%) of ventilation rates measured with capnography and with automated software bioimpedance were within 2 breaths/min of each other. After manual annotation of the bioimpedance channel, 81% of 1-min epochs were within 2 breaths/min of rates measured with capnography. Ventilation rate measured with capnography had good correlation with bioimpedance (r = .82, p < .0001). Inter-rater agreement is estimated to be 0.96 for ventilation rate measured with capnography and 0.93 for rate measured with bioimpedance. Discussion: The software occasionally missed obvious ventilation waveforms and occasionally annotated waveforms obviously caused by chest compressions. Manual review and annotation improved the accuracy of ventilation rates measured with bioimpedance. Approximately 75% to 90% of recordings made with the Philips MRx device are expected to be useful for measurement. Conclusion: Ventilation rate measured with thoracic bioimpedance alone is acceptable using the Philips MRx device. Inter-rater agreement for measurements is excellent.

Ventilation of Wind-Permeable Clothed Cylinder Subject to Periodic Swinging Motion: Modeling and Experimentation

2008 ◽  
Vol 130 (9) ◽  
Author(s):  
N. Ghaddar ◽  
K. Ghali ◽  
B. Jreije
Keyword(s):  
Cotton Fabric ◽  
Current Model ◽  
Ventilation Rate ◽  
External Pressure ◽  
Motion Modeling ◽  
Tracer Gas ◽  
Wind Speeds ◽  
Air Speed ◽  
Local Thermal Comfort ◽  
Ventilation Rates

Abstract A theoretical and experimental study has been performed to determine the ventilation induced by swinging motion and external wind for a fabric-covered cylinder of finite length representing a limb. The estimated ventilation rates are important in determining local thermal comfort. A model is developed to estimate the external pressure distribution resulting from the relative wind around the swinging clothed cylinder. A mass balance equation of the microclimate air layer is reduced to a pressure equation assuming laminar flow in axial and angular directions and that the air layer is lumped in the radial direction. The ventilation model predicts the total renewal rate during the swinging cycle. A good agreement was found between the predicted ventilation rates at swinging frequencies between 40rpm and 60rpm and measured values from experiments conducted in a controlled environmental chamber (air velocity is less than 0.05m∕s) and in a low speed wind tunnel (for air speed between 2m∕s and 6m∕s) using the tracer gas method to measure the total ventilation rate induced by the swinging motion of a cylinder covered with a cotton fabric for both closed and open aperture cases. A parametric study using the current model is performed on a cotton fabric to study the effect of wind on ventilation rates for a nonmoving clothed limb at wind speeds ranging from 0.5m∕sto8m∕s, the effect of a swinging limb in stagnant air at frequencies up to 80rpm, and the combined effect of wind and swinging motion on the ventilation rate. For a nonmoving limb, ventilation rate increases with external wind. In the absence of wind, the ventilation rate increases with increased swinging frequency.

Positive end-expiratory pressure enhances development of a functional residual capacity in preterm rabbits ventilated from birth

2009 ◽  
Vol 106 (5) ◽  
pp. 1487-1493 ◽  
Author(s):  
Melissa L. Siew ◽  
Arjan B. te Pas ◽  
Megan J. Wallace ◽  
Marcus J. Kitchen ◽  
Robert A. Lewis ◽  
...  
Keyword(s):  
Functional Residual Capacity ◽  
Positive End Expiratory Pressure ◽  
Mechanically Ventilated ◽  
Very Preterm ◽  
Lung Aeration ◽  
X Ray Imaging ◽  
Airway Collapse ◽  
Distal Airway ◽  
Dead Space Volume ◽  
Residual Capacity

The factors regulating lung aeration and the initiation of pulmonary gas exchange at birth are largely unknown, particularly in infants born very preterm. As hydrostatic pressure gradients may play a role, we have examined the effect of a positive end-expiratory pressure (PEEP) on the spatial and temporal pattern of lung aeration in preterm rabbit pups mechanically ventilated from birth using simultaneous phase-contrast X-ray imaging and plethysmography. Preterm rabbit pups were delivered by caesarean section at 28 days of gestational age, anesthetized, intubated, and placed within a water-filled plethysmograph (head out). Pups were imaged as they were mechanically ventilated from birth with a PEEP of either 0 cmH2O or 5 cmH2O. The peak inflation pressure was held constant at 35 cmH2O. Without PEEP, gas only entered into the distal airways during inflation. The distal airways collapsed during expiration, and, as a result, the functional residual capacity (FRC) did not increase above the lung's anatomic dead space volume (2.5 ± 0.8 ml/kg). In contrast, ventilation with 5-cmH2O PEEP gradually increased aeration of the distal airways, which did not collapse at end expiration. The FRC achieved in pups ventilated with PEEP (19.9 ± 3.2 ml/kg) was significantly greater than in pups ventilated without PEEP (−2.3 ± 3.5 ml/kg). PEEP greatly facilitates aeration of the distal airways and the accumulation of FRC and prevents distal airway collapse at end expiration in very preterm rabbit pups mechanically ventilated from birth.

Effects of lung expansion on lung liquid production in vitro by lungs from fetal guinea-pigs. II. Evidence for generation of an inhibitory factor

1996 ◽  
Vol 8 (3) ◽  
pp. 347 ◽  
Author(s):  
PG Nelson ◽  
AM Perks
Keyword(s):  
Body Weight ◽  
Guinea Pigs ◽  
Inhibitory Factor ◽  
Dilution Method ◽  
Lung Fluid ◽  
Lung Expansion ◽  
Fluid Production ◽  
Near Term ◽  
Lung Liquid

Lungs from near-term fetal guinea-pigs were supported in vitro for 3 h; lung liquid production was measured by a dye-dilution method using Blue Dextran 2000 [fetuses 63 +/- 2 days of gestation, 97.6 +/- 19.8 (SD) g body weight]. Preparations were incubated in pairs taken from the same mother. Twenty lungs incubated in pairs without treatment (controls) showed no significant changes in fluid production throughout incubation (analysis of variance; regression analysis); rates in successive hours were: first lung, 1.36 +/- 0.39, 1.09 +/- 0.34 and 1.27 +/- 0.42 ml/kg body weight per h; second lung, 1.46 +/- 0.52, 1.09 +/- 0.41 and 1.18 +/- 0.43 ml/kg body weight per h. Twenty lungs were incubated similarly in pairs, but after one hour one lung from each pair was expanded with Krebs-Henseleit saline in volumes approximating those of the first breath (68 +/- 10% of lung volume). The expanded lungs began to reabsorb fluid immediately after expansion; the untreated lungs also stopped production or reached reabsorption by the final hour. Rates in successive hours were: expanded lungs; before expansion, 1.00 +/- 0.21, after expansion, -0.23 +/- 0.17 and 0.14 +/- 0.09 ml/kg body weight per h; unexpanded lungs, 1.27 +/- 0.49, 0.02 +/- 0.01 and -0.01 +/- 0.004 ml/kg body weight per h. The decrease in production was significant for each type of lung. The effects persisted in both expanded and unexpanded lungs in the presence of 1.78 x 10(-5) M phentolamine (n = 12; 70 +/- 2% expansion). The results suggest that expansion of the lungs at birth may release an unknown inhibitory factor, provisionally termed Expansion Factor (EF), within the lungs; this agent, probably not a catecholamine, can change lung fluid production into reabsorption and may partly account for the failure of beta-antagonists to prevent fluid reabsorption at delivery.

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