The preterm infant : evaluating and developing non-invasive respiratory strategies to avoid mechanical ventilation

Avoiding mechanical ventilation of preterm infants is important to prevent morbidity and mortality. Non-invasive ventilation and CPAP has been shown to be superior to intubation and mechanical ventilation in preventing chronic lung disease in very preterm infants.1 . CPAP for infants was first used in the early 70’s. Since then, several different CPAP devices have been developed. Some of them are designed to give long term respiratory support while others are designed for initial support, with the possibility to give positive pressure ventilation (PPV) if needed. Some are expensive and complicated with several add on features while other are cheap, with simple mechanisms and easy to use. The goal for CPAP treatment is to give continuous airway pressure to the infants in order to minimize the work of breathing and improve gas exchange. But are all CPAP systems the same? Do all CPAP systems deliver stable airway pressure which helps the infants with their work of breathing? The overall aim of this thesis was to evaluate existing and newly developed devices for noninvasive respiratory support used in neonates in the DR and the NICU. The focus was on device resistance, pressure stability, imposed work of breathing and interfaces used. The aim of Paper I was to examine the in vitro performance of a new system (rPAP) and to perform a clinical feasibility trial, comparing a T-piece system with face mask, and the new system with face mask or nasal prongs, for initial stabilization of preterm infants. The new device was shown in a mechanical lung model to be pressure stable and have low imposed work of breathing compared to the T-piece. The feasibility trial comparing these devices revealed no safety issues when stabilizing preterm infants with the new device. The aim of Paper II was to examine the in vitro performance of the Medijet CPAP reusable and disposable generators and compare them to other CPAP systems. The main mechanism of CPAP generation for the disposable Medijet generator was shown to be resistance. The Medijet systems shows increasing resistance to breathing with each design generation. Our results suggest that the disposable Medijet should be used cautiously in patients where lowresistance and pressure-stable CPAP is believed to be clinically important. The aim of Paper III was to compare the revised Pumani CPAP system with two traditional bubble CPAP systems, focusing on in-vitro performance and safety. The revised Pumani system had high resistance, high imposed work of breathing and submersion depth had almost no impact on the delivered pressure which is the main CPAP generating mechanism of true bubble CPAP systems. The aim of Paper IV was to evaluate if using the new system (rPAP) with nasal prongs as interface, could reduce the need for intubation of extremely preterm infants in the DR compared to using the standard T-piece system with face mask. The CORSAD randomized controlled trial showed that using the new system decreased delivery room intubations in extremely preterm infants and creates thereby a possibility to avoid mechanical ventilation

Effect of interface dead space on the time taken to achieve changes in set FiO2 during T-piece ventilation : is face mask the optimal interface for neonatal stabilisation?

Publisher Copyright: © Author(s) (or their employer(s)) 2024.Background T-piece is recommended for respiratory support during neonatal stabilisation. Bench studies have shown a delay >30 s in achieving changes in fraction of inspired oxygen (FiO2) at the airway when using the T-piece. Using a face mask adds dead space (DS) to the patient airway. We hypothesised that adding face mask to T-piece systems adversely affects the time required for a change in FiO2 to reach the patient. Methods Neopuff (Fisher and Paykel, Auckland, New Zealand) and rPAP (Inspiration Healthcare, Croydon, UK) were used to ventilate a test lung. DS equivalent to neonatal face masks was added between the T-piece and test lung. Additionally, rPAP was tested with nasal prongs. Time course for change in FiO2 to be achieved at the airway was measured for increase (0.3–0.6) and decrease (1.0–0.5) in FiO2. Primary outcome was time to reach FiO2+/−0.05 of the set target. One-way analysis of variance was used to compare mean time to reach the primary outcome between different DS volumes. Results In all experiments, the mean time to reach the primary outcome was significantly shorter for rPAP with prongs compared with Neopuff and rPAP with face mask DS (p<0.001). The largest observed difference occurred when testing a decrease in FiO2 with 10 mL tidal volume (TV) without leakage (18.3 s for rPAP with prongs vs 153.4 s for Neopuff with face mask DS). The shortest observed time was 13.3 s when increasing FiO2 with 10 mL TV with prongs with leakage and the longest time was 172.7 s when decreasing FiO2 with 4 mL TV and added face mask DS without leak. Conclusion There was a delay in achieving changes in oxygen delivery at the airway during simulated ventilation attributable to the mask volume. This delay was greatly reduced when using nasal prongs as an interface. This should be examined in clinical trials.Peer reviewe

The reading development project LiV : a quest for an equal education

Syftet med studien är att undersöka hur Läsutveckling i Varberg, LiV, praktiseras på kommunens olika skolor samt att undersöka hur LiV-handledare arbetar för att träna elevers avkodningsförmåga. Studien syftar också till att undersöka om Läsutveckling i Varberg, LiV, bidrar till en mer likvärdig utbildning. Läsutveckling i Varberg, LiV, är ett långsiktigt utvecklingsarbete som startade år 2010. LiV syftar till att alla elever ska ges förutsättningar att utveckla en god läsförmåga i grundskolans årskurs 2, där fokus speciellt är riktat på avkodningsförmågan. Studiens tre grundläggande frågeställningar är ”Vilka förutsättningar har LiV-handledare för att föra vidare sin kunskap om läsutveckling till kollegiet?”, ”Hur ser språk-, läs- och skrivutvecklarna samt LiV-handledarna på de metoder som förespråkas och används för att öka elevers läsutveckling?” och ”Vilka konsekvenser får en kommunstyrd satsning som LiV på elevers läsutveckling?”. Studien är utformad utefter en kvalitativ metod där totalt sex informanter har intervjuats genom semistrukturerade intervjuer. Urvalet bestod av fyra verksamma lärare från olika skolor i Varbergs kommun samt kommunens två språk-, läs- och skrivutvecklare. Strukturen för analysen i studien följer ett fenomenografiskt tillvägagångssätt som syftar till att undersöka och beskriva informanternas uppfattningar och erfarenheter av läsutvecklingsarbetet LiV. Resultatet visar att lästräning, med Rydaholmsmetoden, under korta och intensiva arbetspass, främjar elevernas läsutveckling. Det framkommer att läsutvecklingsarbetet LiV är beroende av rektorerna som är viktiga nyckelpersoner för att föra arbetet vidare på respektive skola. Resultatet visar att fortbildningen som ges är värdefull men att LiV-handledarna ser det som problematiskt att finna tid till att handleda övriga kollegor. Studien visar också att läsutvecklingsarbetet LiV bidrar till positiva erfarenheter och upplevelser för lärare i Varbergs kommun. Genom resultatet går det också att utläsa att LiV är effektfullt och att det har genererat i goda resultat för elever i årskurs 2. Det framkommer också att resultatet påverkas av olika faktorer. Sådana faktorer kan vara upptagningsområde, lärmiljöer, rektorbyten, lärarbyten samt socioekonomiska faktorer vilket är viktigt att ha i beaktning.

Correction: Infant CPAP for low-income countries: An experimental comparison of standard bubble CPAP and the Pumani system.

[This corrects the article DOI: 10.1371/journal.pone.0196683.]

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Infant CPAP for low-income countries: An experimental comparison of standard bubble CPAP and the Pumani system.

Access to inexpensive respiratory support to newborn infants improves survival in low-income countries. Standard bubble continuous positive airway pressure (CPAP) has been extensively used worldwide for more than 30 years. One project aimed at providing affordable CPAP is the Pumani system developed by Rice 360°. Compared to standard bubble CPAP the system has an unconventional design. The aim was to compare the Pumani system with two traditional bubble CPAP systems, focusing on in-vitro performance and safety.The Pumani system was compared to traditional bubble CPAP from Fisher & Paykel (Auckland, New Zealand) and Diamedica (Devon, United Kingdom). The systems were tested using static flow resistance and simulated breathing for a range of fresh gas flows and submersion levels.There were large differences between the Pumani CPAP and the conventional bubble CPAP systems. The Pumani system was not pressure stable, had high resistance and high imposed work of breathing. It was not possible to use submersion depth to adjust CPAP without accounting for fresh gas flow.The Pumani design is novel and not similar to any previously described CPAP system. The main mechanism for CPAP generation was resistance, not submersion depth. The system should therefore not be referred to as bubble CPAP. The clinical consequences of its pressure instability and high imposed work of breathing are not known and trials on outcome and safety are needed

Data from: Infant CPAP for low-income countries: an experimental comparison of standard bubble CPAP and the Pumani system

Introduction: Access to inexpensive respiratory support to newborn infants improves survival in low-income countries. Standard bubble continuous positive airway pressure (CPAP) has been extensively used worldwide for more than 30 years. One project aimed at providing affordable CPAP is the Pumani system developed by Rice 360. Compared to standard bubble CPAP the system has an unconventional design. The aim was to compare the Pumani system with two traditional bubble CPAP systems, focusing on in-vitro performance and safety. Methods: The Pumani system was compared to traditional bubble CPAP from Fisher & Paykel (Auckland, New Zealand) and Diamedica (Devon, United Kingdom). The systems were tested using static flow resistance and simulated breathing for a range of fresh gas flows and submersion levels. Results: There were large differences between the Pumani CPAP and the conventional bubble CPAP systems. The Pumani system was not pressure stable, had high resistance and high imposed work of breathing. It was not possible to use submersion depth to adjust CPAP without accounting for fresh gas flow. Discussion: The Pumani design is novel and not similar to any previously described CPAP system. The main mechanism for CPAP generation was resistance, not submersion depth. The system should therefore not be referred to as bubble CPAP. The clinical consequences of its pressure instability and high imposed work of breathing are not known and trials on outcome and safety are needed

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