Carbon dioxide clearance using bubble CPAP with superimposed high-frequency oscillations in a premature infant lung model with abnormal lung mechanics

Comparison of nasal intermittent positive pressure ventilation and bubble CPAP with an in-line high-frequency interrupter in a premature infant lung model

INTRODUCTION

Noninvasive ventilation has become a staple in the care of premature infants. However, failure rates continue to be high in this population. Modifications to noninvasive support, such as nasal intermittent positive pressure ventilation (NIPPV), are used clinically to reduce such failure. Previous in vitro studies have shown improved CO₂ clearance when superimposing high-frequency oscillations onto bubble continuous positive airway pressure (BCPAP).

OBJECTIVE

To compare the CO₂ clearance of NIPPV to BCPAP with an in-line high-frequency interrupter (HFI) in a premature infant lung model.

METHODS

A premature infant lung model was connected to either a Dräger VN500 for delivery of NIPPV or a BCPAP device with superimposed high-frequency oscillations generated by an in-line HFI. Change in end-tidal CO₂  (ETCO₂ ) and mean airway pressure at the simulated trachea were measured and compared for both noninvasive modalities.

RESULTS

Superimposing HF oscillations onto BCPAP with an in-line HFI resulted in improved CO₂ clearance relative to BCPAP alone for all tested oscillation frequencies at all CPAP levels (p < 0.001). NIPPV also resulted in improved CO₂  clearance relative to nasal CPAP (NCPAP) alone (p < 0.001). Among the tested settings, BCPAP with an in-line HFI resulted in decreased ETCO₂ relative to BCPAP ranging from -14% to -36%, while NIPPV resulted in decreased ETCO₂  relative to NCPAP ranging from -2% to -12%.

CONCLUSION

Superimposing high-frequency oscillations onto BCPAP using a novel in-line HFI was found to be more effective at clearing CO₂ than NIPPV in a premature infant lung model.

Effect of Continuous Nutrition Management Intervention on Nutritional Status and Development of Premature Infants Based on Mobile Medical APP

Objective

To explore the effect of continuous nutrition management intervention based on mobile medical APP on the nutritional status and development of premature infants.

Methods

Eighty premature infants treated in our hospital from May 2019 to April 2021 were enrolled. The patients were randomly divided into the control group and research group. The control group received routine nursing, and the research group received continuous nutrition management intervention based on mobile medical APP. The Neonatal Behavioral Neurological Assessment (NBNA) score, pain score, height, weight, head circumference, intellectual development score, serum Prealbumin (PA), retinol-binding protein (RBP), and disease occurrence were elucidated.

Results

First of all, the NBNA scores of the two groups were compared. The behavioral ability, passive muscle tension, active muscle tension, original reflex, and general evaluation scores of the research group were significantly higher when compared to the control. Secondly, we compared the pain scores of the two groups, there was no significant difference between the two groups before nursing (P > 0.05), but the pain scores of the research group were lower compared to the control group during the period of blood collection, recovery, discharge, and 6 months after discharge (P < 0.05). Compared with the growth and development indexes of the two groups, there was no significant difference between the two groups before nursing (P > 0.05). After nursing, the GDS score of the two groups increased, and the GDS score of the research group was higher than that of the control group. The difference of data was statistically significant (P < 0.05). Compared with the motor scores of the two groups, there was no significant difference between the two groups before nursing (P > 0.05). After nursing, the motor scores of the two groups increased, and the scores of PDMS-2 and TIMP in the research group were higher than those in the control group, and the difference was statistically significant (P < 0.05). There was no significant difference in serum PA and RBP before nursing, but the serum PA and RBP in the two groups increased after nursing, and the PA and RBP in the research group were higher than those in the control group, and the difference was statistically significant (P < 0.05). Finally, we compared the incidence of diseases between the two groups. Before nursing, the incidence of infection, retinopathy, chronic lung injury and anemia in the research group was lower, when compared to the control, and the difference was statistically significant (P < 0.05).

Conclusion

The intervention strategy of continuous nutrition management based on mobile medical APP for premature infants can significantly strengthen their nutritional status after discharge, promote their growth and development, improve their nutritional status, reduce the incidence of diseases in premature infants, and then enhance their quality of life.

A novel in-line high frequency interrupter for use with bubble CPAP: A feasibility study in a premature lamb model

BACKGROUND

Recent in vitro testing of high frequency (HF) oscillation applied to bubble continuous positive airway pressure (BCPAP) using a novel flow interrupter device (HFI) demonstrated significantly improved CO2 washout while not altering delivered mean airway pressure (MAP) in a premature infant lung model. This study's aim was to evaluate the safety and efficacy of the HFI paired with BCPAP in an animal model of prematurity prior to clinical testing.

DESIGN/METHODS

Twelve fetal lambs, 131-135 days gestation, weight 3.51±0.42 kg, were delivered by Cesarean section. The lambs were supported by mechanical ventilation and weaned to spontaneous breathing with BCPAP at 6 cmH2O. A combined CO2/airflow sensor measured end-tidal (EtCO2) and tidal volume (VT). Blood gases, heart rate (HR), arterial pressure (Part), minute ventilation (MV), MAP, ventilatory efficiency index (VEI), thoracoabdominal phase angle and labored breathing index (LBI) were recorded over a 10-minute baseline period followed by four randomized 10-minute intervals with HFI set to either 8, 10, 12 or 15 Hz.

RESULTS

EtCO2 decreased from baseline by 11.1±2.2SE%, 16.6±4.3SE%, 13.5±4.9SE%, and 19.5±4.5SE% at 8, 10, 12, and 15 Hz respectively (p <  0.001). Blood gases, SpO2, HR, Part, MAP, VT, MV, esophageal pressure, phase angle, and LBI underwent no significant change with HF. Respiratory rate decreased, and VEI increased, by 14.9±4.5SD% (p = 0.037) and 83±22SD% (p <  0.011) respectively, averaged over all frequencies.

CONCLUSIONS

We demonstrated the safety and efficacy of a novel BCPAP flow interrupter device. HF applied to the respiratory system resulted in significantly improved CO2 clearance and ventilation efficiency with no deleterious physiological effects in a pre-term lamb model.

Conceptual model of low-cost improvised bubble continuous positive airway pressure device for adults and its potential use in the COVID-19 pandemic

Low-cost improvised continuous positive airway pressure (CPAP) device is safe and efficacious in neonatal respiratory distress. There is a great necessity for similar device in adults, and this has been especially made apparent by the recent Coronavirus Disease 2019 (COVID-19) pandemic, which is unmasking the deficiencies of healthcare system in several low-resource countries. We propose a simplified and inexpensive model of improvised CPAP in adults using locally available resources including aquarium air pumps and a novel pressure release mechanism. Although the safety and efficacy of improvised CPAP in adults are not established, the conceptual model we propose has the potential to serve as a lifesaving technology in many low-resource settings during this ongoing pandemic and thus calls for expedited research.

An aquarium air pump, few plastic tubes, and a tight-fitting mask can be used to form an improvised continuous positive airway pressure (CPAP) device that could be lifesaving for many in low-resource countries. Although the device seems promising, further research is needed to establish its safety and efficacy.

Pediatric pulmonology year in review 2020: Physiology

Pulmonary physiology is a core element of pediatric pulmonology care and research. This article reviews some of the notable publications in physiology that were published in Pediatric Pulmonology in 2020.

Preserved pressure delivery during high-frequency oscillation of bubble CPAP in a premature infant lung model with both normal and abnormal lung mechanics

BACKGROUND

Bubble continuous positive airway pressure (BCPAP) generates pressure oscillations which are suggested to improve gas exchange through mechanisms similar to high frequency (HF) ventilation. In a previous in-vitro lung model with normal lung mechanics, significantly improved CO₂ washout was demonstrated using an HF interrupter in the supply flow of a BCPAP system. The effect of HF with BCPAP on delivered airway pressure (Paw) has not been fully investigated in a lung model having abnormal pulmonary mechanics.

OBJECTIVE

To measure Paw in an infant lung model simulating normal and abnormal pulmonary compliance and resistance while connected to a BCPAP system with superimposed HF oscillations created using an in-line flow interrupter.

DESIGN/METHODS

A premature infant lung model with either: normal lung mechanics, compliance 1.0 ml/cm H₂ O, airway resistance 56 cm H₂ O/(L/s); or abnormal mechanics, compliance 0.5 ml/cm H₂ O, airway resistance 136 cm H₂ O/(L/s), was connected to BCPAP with HF at either 4, 6, 8, 10, or 12 Hz. Paw was measured at BCPAPs of 4, 6, and 8 cm H₂ O and respiratory rates (RR) of 40, 60, and 80 breaths/min and 6.0 ml tidal volume.

RESULTS

Mean Paw averaged over all five frequencies showed no significant change from non-oscillated levels at all BCPAPs and RRs for both lung models. Paw amplitudes (peak-to-trough) during oscillation were significantly greater than the non-oscillated levels by an average of 1.7 ± 0.5 SD and 2.6 ± 0.5 SD cm H₂ O (p < .001) for the normal and abnormal models, respectively.

CONCLUSIONS

HF oscillation of BCPAP using a flow interrupter did not alter mean delivered Paw compared to non-oscillated BCPAP for both normal and abnormal lung mechanics models. This simple modification to BCPAP may be a useful enhancement to this mode of non-invasive respiratory support.