Dataset Information

Infant tidal flow-volume parameters and arousal state.

ABSTRACT:

Background

Infant lung function can be assessed with tidal flow-volume (TFV) loops. While TFV loops can be measured in both awake and sleeping infants, the influence of arousal state in early infancy is not established. The aim of the present study was to determine whether TFV loop parameters in healthy infants differed while awake compared to the sleeping state at 3 months of age.

Methods

From the population-based Scandinavian Preventing Atopic Dermatitis and ALLergies in children (PreventADALL) birth cohort, 91 infants had reproducible TFV loops measured with Exhalyzer^® D in both the awake and sleeping state at 3 months of age. The TFV loops were manually selected according to a standardised procedure. The ratio of time to peak tidal expiratory flow (t _PTEF) to expiratory time (t _E) and the corresponding volume ratio (V _PTEF/V _E), as well as tidal volume (V _T) and respiratory rate were compared using nonparametric tests.

Results

The mean (95% CI) t _PTEF/t _E was significantly higher while awake compared to the sleeping state: 0.39 (0.37-0.41) versus 0.28 (0.27-0.29); with the corresponding V _PTEF/V _E of 0.38 (0.36-0.40) versus 0.29 (0.28-0.30). The V _T was similar, while the respiratory rate was higher while awake compared to the sleeping state: 53 (51-56) breaths·min^-1 versus 38 (36-40) breaths·min^-1.

Conclusion

Higher t _PTEF/t _E, V _PTEF/V _E and respiratory rate, but similar V _T while awake compared to the sleeping state suggests that separate normative TFV loop values according to arousal state may be required in early infancy.

SUBMITTER: Bains KES

PROVIDER: S-EPMC9574559 | biostudies-literature | 2022 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Infant tidal flow-volume parameters and arousal state.

Bains Karen Eline Stensby KES Färdig Martin M Gudmundsdóttir Hrefna Katrín HK Almqvist Catarina C Hedlin Gunilla G Nordhagen Live S LS Rehbinder Eva M EM Skjerven Håvard O HO Söderhäll Cilla C Vettukattil Riyas R Nordlund Björn B Lødrup Carlsen Karin C KC

ERJ open research 20221017 4

<h4>Background</h4>Infant lung function can be assessed with tidal flow-volume (TFV) loops. While TFV loops can be measured in both awake and sleeping infants, the influence of arousal state in early infancy is not established. The aim of the present study was to determine whether TFV loop parameters in healthy infants differed while awake compared to the sleeping state at 3 months of age.<h4>Methods</h4>From the population-based Scandinavian Preventing Atopic Dermatitis and ALLergies in childre ...[more]

PMID: 36267897

Similar Datasets

Project description:BackgroundWe observed that increasing fresh gas flow (FGF) decreased exhaled tidal volume (VT) during pressure control ventilation (PCV). A literature search produced no such description whereby unintended VT changes occur with FGF changes during PCV.MethodsTo model an infant's lungs, 1 lung of a mechanical lung model (Dual Adult TTL 1600; Michigan Instruments, Inc, Grand Rapids, MI) was set at a compliance of 0.0068 L/cm H2O. An Rp50 resistor (27.2 cm H2O/L/s at 15 L/min) simulated normal bronchial resistance. The simulated lung was connected to a pediatric breathing circuit via a 3.5-mm cuffed endotracheal tube. A ventilator with PCV capability (Model 7900; Aestiva, GE Healthcare, Madison, WI) measured exhaled VT, and a flow monitor (NICO; Respironics, Murraysville, PA) measured peak inspiratory flow, positive end-expiratory pressure (PEEP), and peak inspiratory pressure. In PCV mode, exhaled VT displayed by the ventilator at FGF rates of 1, 6, 10, and 15 L/min was manually recorded across multiple ventilator settings. This protocol was repeated for the Avance CS2 anesthesia machine (GE Healthcare).ResultsFor the Aestiva, higher FGF rates in PCV mode decreased exhaled VT. Exhaled VT for FGFs of 1, 6, 10, and 15 L/min were on average 48, 34.9, 16.5, and 10 mL, respectively, at ventilator settings of inspiratory pressure of 10 cm H2O, PEEP of 0 cm H2O, and respiratory rate of 20 breaths/min. This is a decrease by up to 27%, 65.6%, and 79.2% when FGFs of 6, 10, and 15 L/min are compared with a FGF of 1 L/min, respectively. In the GE Avance CS2 at the same ventilator settings, VT for FGF rates of 1, 6, 10, and 15 L/min were on average 46, 43, 40.4, and 39.7 mL, respectively. The FGF effect on VT was not as pronounced with the GE Avance CS2 as with the GE Aestiva.ConclusionsFGF has a significant effect on VT during PCV in the Aestiva bellows ventilator, suggesting caution when changing FGF during PCV in infants. Our hypothesis is that at higher FGF rates, an inadvertent PEEP is developed by the flow resistance of the ventilator relief valve that is not recognized by the ventilator. In turn, less change in pressure is needed to reach the set inspiratory pressure, resulting in lower VT delivery at higher FGF rates. This underappreciated FGF-VT interaction during PCV with a bellows ventilator may be clinically significant in pediatric patients; prospective data collection in patients is needed for further evaluation.

Project description:ImportanceIn patients who undergo mechanical ventilation during surgery, the ideal tidal volume is unclear.ObjectiveTo determine whether low-tidal-volume ventilation compared with conventional ventilation during major surgery decreases postoperative pulmonary complications.Design, setting, and participantsSingle-center, assessor-blinded, randomized clinical trial of 1236 patients older than 40 years undergoing major noncardiothoracic, nonintracranial surgery under general anesthesia lasting more than 2 hours in a tertiary hospital in Melbourne, Australia, from February 2015 to February 2019. The last date of follow-up was February 17, 2019.InterventionsPatients were randomized to receive a tidal volume of 6 mL/kg predicted body weight (n = 614; low tidal volume group) or a tidal volume of 10 mL/kg predicted body weight (n = 592; conventional tidal volume group). All patients received positive end-expiratory pressure (PEEP) at 5 cm H2O.Main outcomes and measuresThe primary outcome was a composite of postoperative pulmonary complications within the first 7 postoperative days, including pneumonia, bronchospasm, atelectasis, pulmonary congestion, respiratory failure, pleural effusion, pneumothorax, or unplanned requirement for postoperative invasive or noninvasive ventilation. Secondary outcomes were postoperative pulmonary complications including development of pulmonary embolism, acute respiratory distress syndrome, systemic inflammatory response syndrome, sepsis, acute kidney injury, wound infection (superficial and deep), rate of intraoperative need for vasopressor, incidence of unplanned intensive care unit admission, rate of need for rapid response team call, intensive care unit length of stay, hospital length of stay, and in-hospital mortality.ResultsAmong 1236 patients who were randomized, 1206 (98.9%) completed the trial (mean age, 63.5 years; 494 [40.9%] women; 681 [56.4%] undergoing abdominal surgery). The primary outcome occurred in 231 of 608 patients (38%) in the low tidal volume group compared with 232 of 590 patients (39%) in the conventional tidal volume group (difference, -1.3% [95% CI, -6.8% to 4.2%]; risk ratio, 0.97 [95% CI, 0.84-1.11]; P = .64). There were no significant differences in any of the secondary outcomes.Conclusions and relevanceAmong adult patients undergoing major surgery, intraoperative ventilation with low tidal volume compared with conventional tidal volume, with PEEP applied equally between groups, did not significantly reduce pulmonary complications within the first 7 postoperative days.Trial registrationANZCTR Identifier: ACTRN12614000790640.

Dataset Information

Infant tidal flow-volume parameters and arousal state.

Background

Methods

Results

Conclusion

Publications

Infant tidal flow-volume parameters and arousal state.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets