The effect of endotracheal suction on regional tidal ventilation and end-expiratory lung volume

Tingay, David G.; Copnell, Beverley; Grant, Caroline A.; Dargaville, Peter A.; Dunster, Kimble; Schibler, Andreas

doi:10.1007/s00134-010-1849-x

Cited by 53 publications

(64 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…All signals were sampled at 1,000 Hz and acquired using a Powerlab/ Lab Chart system (Version 7, AD Instruments, Sydney, Australia). Relative changes in regional thoracic volume were measured using the Thorascan software package sampling at 25 Hz (37,38). Arterial blood gas analysis was performed at 5, 10, and 15 min of life, and then 15-minutely until 90 min life and then 30-minutely until completion of the study.…”

Section: Experimental Set-upmentioning

confidence: 99%

Intratracheal atomized surfactant provides similar outcomes as bolus surfactant in preterm lambs with respiratory distress syndrome

et al. 2016

View full text Add to dashboard Cite

Background: Aerosolization of exogenous surfactant remains a challenge. This study is aimed to evaluate the efficacy of atomized poractant alfa (Curosurf ) administered with a novel atomizer in preterm lambs with respiratory distress syndrome. Methods: Twenty anaesthetized lambs, 127 ± 1 d gestational age, (mean ± SD) were instrumented before birth and randomized to receive either (i) positive pressure ventilation without surfactant (Control group), (ii) 200 mg/kg of bolus instilled surfactant (Bolus group) at 10 min of life or (iii) 200 mg/kg of atomized surfactant (Atomizer group) over 60 min from 10 min of life. All lambs were ventilated for 180 min with a standardized protocol. Lung mechanics, regional lung compliance (electrical impedance tomography), and carotid blood flow (CBF) were measured with arterial blood gas analysis. results: Dynamic compliance and oxygenation responses were similar in the Bolus and Atomizer groups, and both better than Control by 180 min (all P < 0.05; two-way ANOVA). Both surfactant groups demonstrated more homogeneous regional lung compliance throughout the study period. There were no differences in CBF conclusion: In a preterm lamb model, atomized surfactant resulted in similar gas exchange and mechanics as bolus administration. This study suggests evaluation of supraglottic atomization with this system when noninvasive support is warranted. s urfactant replacement therapy is a well-established standard of care for the treatment and prevention of neonatal respiratory distress syndrome (RDS), significantly reducing mortality and morbidity (1). Currently, endotracheal instillation is the only approved method of administration. However, over the last decade, the management of mild to moderate RDS has dramatically changed, endotracheal tube (ETT) intubation is often avoided and infants were managed with noninvasive modalities, such as continuous positive airway pressure whilst spontaneously breathing. In this population, surfactant administration is generally only provided when oxygen requirement increases and intubation is necessary (2,3).The increase in noninvasive ventilation use has led to less invasive methods of surfactant delivery during continuous positive airway pressure being developed (4,5). All reported methods require technical skills, some degree of invasive intervention, and still involve instillation of liquid surfactant directly into the trachea via a process that is not dissimilar to intubation (6-8). Nebulization of surfactant offers an attractive alternative. Unfortunately, studies of nebulized surfactant have shown inconsistent clinical response and surfactant distribution (9-16). Moreover, most of the studies, even those in which a lung function improvement was observed, reported very low (<10%) fractions of surfactant deposition into the lung (9,12,(17)(18)(19)(20). Notwithstanding differences in nebulizer design, and thus particle size production, such modest deposition is likely due to the fact that most studies used aerosols generated extracorporeally by ...

show abstract

Section: Experimental Set-upmentioning

confidence: 99%

Intratracheal atomized surfactant provides similar outcomes as bolus surfactant in preterm lambs with respiratory distress syndrome

et al. 2016

View full text Add to dashboard Cite

show abstract

“…V LRIP voltage signals were calibrated to the known volumes from the static pressure-volume curve using the in-built multipoint linear calibration module in LabChart. Relative impedance measured by EIT was analyzed offline (AUSPEX V1.6; Carefusion) using our previously described method (32,35,36). The EIT recordings were referenced to the signal immediately prior to ventilation to determine relative change in impedance (ΔZ) from birth.…”

Section: Stepwise Peep Vs Si At Birthmentioning

confidence: 99%

Effect of sustained inflation vs. stepwise PEEP strategy at birth on gas exchange and lung mechanics in preterm lambs

et al. 2013

View full text Add to dashboard Cite

Background: Sustained inflation (SI) at birth facilitates establishment of functional residual capacity (FRC) in the preterm lung, but the ideal lung recruitment strategy is unclear. We have compared the effect of SI and a stepwise positive endexpiratory pressure (PEEP; SEP) strategy in a preterm model. Methods: 127 d gestation lambs received either 20-s SI (n = 9) or 2 cmH 2 O stepwise PEEP increases to 20 cmH 2 O every 10 inflations, and then decreases to 6 cmH 2 O (n = 10). Ventilation continued for 70 min, with surfactant administered at 10 min. Alveolar-arterial oxygen gradient (AaDO 2 ), compliance (C dyn ), end-expiratory thoracic volume (EEV RIP ; respiratory inductive plethysmography), and EEV and C dyn in the gravitydependent and nondependent hemithoraces (electrical impedance tomography) were measured throughout. Early mRNA markers of lung injury were analyzed using quantitative real-time PCR. results: From 15 min of life, AaDO2 was lower in SEP group (P < 0.005; two-way ANOVA). SEP resulted in higher and more homogeneous C dyn (P < 0.0001). Mean (SD) EEV RIP at 5 min was 18 (9) ml/kg and 6 (5) ml/kg following SEP and SI, respectively (P = 0.021; Bonferroni posttest); this difference was due to a greater nondependent hemithorax EEV. There was no difference in markers of lung injury. conclusion: An SEP at birth improved gas exchange, lung mechanics, and EEV, without increasing lung injury, compared to the SI strategy used.

show abstract

“…P AO and flow signals were digitized (DAQCARD 6036-E, National Instruments, Austin, TX) at a sampling rate of 600 Hz and recorded to a laptop computer using custom-built programs for data acquisition developed using LabVIEW software (National Instruments). Changes in global and regional electrical impedance, which are related to V L , were measured by EIT sampling at 44 Hz using the methodology we described previously (36). All parameters were measured continuously throughout mapping of the pressure-volume relationship described as follows.…”

Section: Articles Zannin Et Almentioning

confidence: 99%

Optimal mean airway pressure during high-frequency oscillatory ventilation determined by measurement of respiratory system reactance

et al. 2013

View full text Add to dashboard Cite

Background:The aims of the present study were (i) to characterize the relationship between mean airway pressure (P AW ) and reactance measured at 5 Hz (reactance of the respiratory system (X RS ) , forced oscillation technique) and (ii) to compare optimal P AW (P opt ) defined by X RS , oxygenation, lung volume (V L ), and tidal volume (V T ) in preterm lambs receiving high-frequency oscillatory ventilation (HFOV). Methods: Nine 132-d gestation lambs were commenced on HFOV at P AW of 14 cmH 2 O (P start ). P AW was increased stepwise to a maximum pressure (P max ) and subsequently sequentially decreased to the closing pressure (P cl , oxygenation deteriorated) or a minimum of 6 cmH 2 O, using an oxygenation-based recruitment maneuver. X RS , regional V L (electrical impedance tomography), and V T were measured immediately after (t 0min ) and 2 min after (t 2min ) each P AW decrement. P opt defined by oxygenation, X RS , V L , and V T were determined. results: The P AW -X RS and P AW -V T relationships were dome shaped with a maximum at P cl +6 cmH 2 O, the same point as P opt defined by V L . Below P cl +6 cmH 2 O, X RS became unstable between t 0min and t 2min and was associated with derecruitment in the dependent lung. P opt , as defined by oxygenation, was lower than the P opt defined by X RS , V L , or V T . conclusion: X RS has the potential as a bedside tool for optimizing P AW during HFOV. h igh-frequency oscillatory ventilation (HFOV) is used to treat severe neonatal lung disease and has the potential to reduce ventilator-induced lung injury when applied optimally (1,2). HFOV optimally applied aims to recruit the lung and subsequently reduce mean airway pressure (P AW ) to an optimal pressure (P opt ) that achieves optimal lung recruitment at the lowest distending pressure (open lung strategy) (3,4). However, identification and maintenance of P opt remains challenging, particularly in the newly born, whose lungs are in a highly dynamic state because of fluid reabsorption and establishment of functional residual capacity (5). The lack of appropriate tools for the bedside assessment and continuous monitoring of lung function in infants makes targeting of P opt even more difficult.Oxygenation, evaluated by monitoring oxygen saturation (Sp O2 ), is most commonly used for targeting P opt during HFOV in clinical practice (6). However, Sp O2 is an imperfect guide for P AW titration as it is relatively uniform over a wide range of airway pressures and volumes (7). Beginning with the observations of Suter et al. (8), the notion that lung mechanics can guide pressure settings during mechanical ventilation has been examined carefully. For conventional ventilation, a relationship between end-expiratory lung volume (V L ), recruitment, and tidal breath mechanics has been demonstrated repeatedly (9,10). During HFOV, the same theoretical considerations apply (3), but the best means of assessing the mechanics of the oscillated lung remains unclear.A promising approach to noninvasive bedside assessment of lung mechanics ...

show abstract

The effect of endotracheal suction on regional tidal ventilation and end-expiratory lung volume

Abstract: ETT suction causes transient loss of EELV and V(T) throughout the lung. Catheter size exerts a greater influence than suction method, with CS only protecting against derecruitment when a small catheter is used, especially in the non-dependent lung.

Cited by 53 publications

References 43 publications

Intratracheal atomized surfactant provides similar outcomes as bolus surfactant in preterm lambs with respiratory distress syndrome

Intratracheal atomized surfactant provides similar outcomes as bolus surfactant in preterm lambs with respiratory distress syndrome

Effect of sustained inflation vs. stepwise PEEP strategy at birth on gas exchange and lung mechanics in preterm lambs

Optimal mean airway pressure during high-frequency oscillatory ventilation determined by measurement of respiratory system reactance

Contact Info

Product

Resources

About