Neopuff T-piece mask resuscitator: is mask leak related to watching the pressure dial?

One-rescuer newborn CPR using a face mask or an i-gel supraglottic airway and two-finger compressions – A manikin study with cross-over desgin

Introduction

When unanticipated neonatal asphyxia occurs, it may be necessary for a single resuscitator to commence advanced resuscitation before others arrive. We hypothesised that a single rescuer can provide positive pressure ventilations and chest compressions using higher inflation pressures and better adherence to the recommended compression rate with an i-gel supraglottic airway than with a face mask.

Method

A manikin-based cross-over study was conducted. Twenty-one midwives performed both positive pressure ventilation using a T-piece and chest compressions with the two-finger technique on a newborn manikin alone. They performed ventilation with a face mask or an i-gel. The peak inspiratory pressure (PIP) was set to 30 cmH₂O. The actual PIPs were evaluated based on the values displayed on the manometer. The total amount of time taken to complete 30 cycles of three compressions and one ventilation was also evaluated.

Results

The mean of the average PIP for each participant was significantly lower with a face mask than with an i-gel (17.3 ± 4.4 vs 28.2 ± 2.0 cmH₂O, p < 0.00001). The amount of time taken to complete 30 cycles was significantly longer with a face mask than with an i-gel (66.2 ± 6.1 vs 60.6 ± 3.4 seconds, p < 0.0001).

Conclusion

During one-rescuer newborn resuscitation using a T-piece and the two-finger technique, the PIPs are consistently high and 30 cycles of CPR are better adhered to 60 seconds using an i-gel.

Novel Neonatal Simulator Provides High-Fidelity Ventilation Training Comparable to Real-Life Newborn Ventilation

Face mask ventilation of apnoeic neonates is an essential skill. However, many non-paediatric healthcare personnel (HCP) in high-resource childbirth facilities receive little hands-on real-life practice. Simulation training aims to bridge this gap by enabling skill acquisition and maintenance. Success may rely on how closely a simulator mimics the clinical conditions faced by HCPs during neonatal resuscitation. Using a novel, low-cost, high-fidelity simulator designed to train newborn ventilation skills, we compared objective measures of ventilation derived from the new manikin and from real newborns, both ventilated by the same group of experienced paediatricians. Simulated and clinical ventilation sequences were paired according to similar duration of ventilation required to achieve success. We found consistencies between manikin and neonatal positive pressure ventilation (PPV) in generated peak inflating pressure (PIP), mask leak and comparable expired tidal volume (eV_T), but positive end-expiratory pressure (PEEP) was lower in manikin ventilation. Correlations between PIP, eV_T and leak followed a consistent pattern for manikin and neonatal PPV, with a negative relationship between eV_T and leak being the only significant correlation. Airway obstruction occurred with the same frequency in the manikin and newborns. These findings support the fidelity of the manikin in simulating clinical conditions encountered during real newborn ventilation. Two limitations of the simulator provide focus for further improvements.

Newborn resuscitation devices: The known unknowns and the unknown unknowns

Infant resuscitation devices used at birth must be capable of delivering adequate and consistent ventilation in a controlled and predictable manner to a wide patient weight range, and combinations of transitional lung states. Manual inflation resuscitation devices delivering positive pressure lung inflation at birth can be classified broadly into two types: 1) flow generating, ie silicone self-inflating bags (SIB) also known as bag valve mask (BVM) and 2) flow dependent, ie anaesthetic flow inflating bag (FIB) and t-piece resuscitator (TPR) systems (eg: Neopuff, GE Panda and Draeger Resuscitaires). Globalization, lower production costs, and an expanding market need for devices, has led to a proliferation of brands (both reusable and single use) within a class type. T-piece resuscitators have become the dominant device particularly in high income countries. There remains a paucity of information on the performance characteristics of these devices and their ability to provide the required respiratory parameters for effective and safe ventilation across the full-expected weight range and lung states to which they will be applied. This review aims to inform current clinical practise on the biomechanical efficiency, reliability and efficacy of the most common devices used to apply PPV to newborns and infants ≤10 kgs.

Neopuff T-piece resuscitator mask ventilation: Does mask leak vary with different peak inspiratory pressures in a manikin model?

AIM

The aim of this study was to compare mask leak with three different peak inspiratory pressure (PIP) settings during T-piece resuscitator (TPR; Neopuff) mask ventilation on a neonatal manikin model.

METHODS

Participants were neonatal unit staff members. They were instructed to provide mask ventilation with a TPR with three PIP settings (20, 30, 40 cm H₂ O) chosen in a random order. Each episode was for 2 min with 2-min rest period. Flow rate and positive end-expiratory pressure (PEEP) were kept constant. Airway pressure, inspiratory and expiratory tidal volumes, mask leak, respiratory rate and inspiratory time were recorded. Repeated measures analysis of variance was used for statistical analysis.

RESULTS

A total of 12 749 inflations delivered by 40 participants were analysed. There were no statistically significant differences (P > 0.05) in the mask leak with the three PIP settings. No statistically significant differences were seen in respiratory rate and inspiratory time with the three PIP settings. There was a significant rise in PEEP as the PIP increased. Failure to achieve the desired PIP was observed especially at the higher settings.

CONCLUSIONS

In a neonatal manikin model, the mask leak does not vary as a function of the PIP when the flow rate is constant. With a fixed rate and inspiratory time, there seems to be a rise in PEEP with increasing PIP.

Neopuff T-piece resuscitator: does device design affect delivered ventilation?

BACKGROUND

The T-piece resuscitator (TPR) is in common use worldwide to deliver positive pressure ventilation during resuscitation of infants <10 kg. Ease of use, ability to provide positive end-expiratory pressure (PEEP), availability of devices inbuilt into resuscitaires and cheaper disposable options have increased its popularity as a first-line device for term infant resuscitation. Research into its ventilation performance is limited to preterm infant and animal studies. Efficacy of providing PEEP and the use of TPR during term infant resuscitation are not established.

AIM

The aim of this study is to determine if delivered ventilation with the Neopuff brand TPR varied with differing (preterm to term) test lung compliances (Crs) and set peak inspiratory pressures (PIP).

DESIGN

A single operator experienced in newborn resuscitation provided positive pressure ventilation in a randomised sequence to three different Crs models (0.5, 1 and 3 mL/cmH₂O) at three different set PIP (20, 30 and 40 cmH₂O). Set PEEP (5 cmH₂O), gas flow rate and inflation rate were the same for each sequence.

RESULTS

A total of 1087 inflations were analysed. The delivered mean PEEP was Crs dependent across set PIP range, rising from 4.9 to 8.2 cmH₂O. At set PIP 40 cmH₂O and Crs 3 mL/cmH₂O, the delivered mean PIP was significantly lower at 35.3 cmH₂O.

CONCLUSIONS

As Crs increases, the Neopuff TPR can produce clinically significant levels of auto-PEEP and thus may not be optimal for the resuscitation of term infants with healthy lungs.

Mask leak increases and minute ventilation decreases when chest compressions are added to bag ventilation in a neonatal manikin model

AIM

To determine changes in respiratory mechanics when chest compressions are added to mask ventilation, as recommended by the International Liaison Committee on Resuscitation (ILCOR) guidelines for newborn infants.

METHODS

Using a Laerdal Advanced Life Support leak-free baby manikin and a 240-mL self-inflating bag, 58 neonatal staff members were randomly paired to provide mask ventilation, followed by mask ventilation with chest compressions with a 1:3 ratio, for two minutes each. A Florian respiratory function monitor was used to measure respiratory mechanics, including mask leak.

RESULTS

The addition of chest compressions to mask ventilation led to a significant reduction in inflation rate, from 63.9 to 32.9 breaths per minute (p < 0.0001), mean airway pressure reduced from 7.6 to 4.9 cm H2 O (p < 0.001), minute ventilation reduced from 770 to 451 mL/kg/min (p < 0.0001), and there was a significant increase in paired mask leak of 6.8% (p < 0.0001).

CONCLUSION

Adding chest compressions to mask ventilation, in accordance with the ILCOR guidelines, in a manikin model is associated with a significant reduction in delivered ventilation and increase in mask leak. If similar findings occur in human infants needing an escalation in resuscitation, there is a potential risk of either delay in recovery or inadequate response to resuscitation.

Leak during manual neonatal ventilation and its effect on the delivered pressures and volumes: an in vitro study

BACKGROUND

Mask leak is a frequent problem during manual ventilation. Our aim was to investigate the effect of predefined leaks on delivered peak inflation pressure (PIP), positive end-expiratory pressure (PEEP) and tidal volume (V(t)) when using different neonatal manual ventilation devices.

METHODS

A neonatal-lung model was ventilated at different respiratory rates (RRs, 40, 60, 80/min) using a mechanically operated self-inflating bag (SIB) and a manually operated T-piece resuscitator (PIP = 20 cm H(2)O, PEEP = 5 cm H(2)O). Four open tubes of different lengths, which produced up to 90% leak, were consecutively attached between the ventilation device and the lung model. A pneumotachograph was used to measure pressures, flow and volume.

RESULTS

With increasing leak (0-90%) PIP and PEEP decreased significantly (p < 0.001) for both devices. Using the SIB, the mean ± SD PIP fell from 20.1 ± 0.3 to 15.9 ± 7 cm H(2)O and PEEP fell from 5.0 ± 0 to 0.3 ± 0.5 cm H(2)O, leading to an increased pressure difference (Δp); V(t) increased from 8.8 ± 0.7 to 11.1 ± 0.8 ml (p < 0.001). With increasing RRs, the leak-dependent changes were significantly lower (p < 0.001). Using the T-piece resuscitator, PIP dropped independent of RRs from 20.3 ± 0.5 to 18.5 ± 0.6 cm H(2)O and PEEP from 5.1 ± 0.4 to 4.0 ± 0 cm H(2)O, while Δp and V(t) did not differ significantly.

CONCLUSION

The decrease in PIP and PEEP with increasing leak is RR dependent and distinctly higher when using an SIB compared to a T-piece device. In contrast to V(t) delivered with the SIB, V(t) delivered by the T-piece resuscitator was nearly constant even for leaks up to 90%.