Newborn manikin study shows that physicians often fail to detect correct lung compliance when using a self-inflating bag

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.

T-piece resuscitators: can they provide safe ventilation in a low compliant newborn lung?

BACKGROUND

T-piece resuscitators (TPRs) are used for primary newborn resuscitation in birthing and emergency rooms worldwide. A recent study has shown spikes in peak inflation pressure (PIP) over set values with two brands of TPRs inbuilt into infant warmer/resuscitation platforms. We aimed to compare delivered ventilation between two TPR drivers with inflation pressure spikes to a standard handheld TPR in a low test lung compliance (Crs), leak-free bench test model.

METHODS

A single operator provided positive pressure ventilation to a low compliance test lung model (Crs 0.2-1 mL/cmH₂O) at set PIP of 15, 25, 35 and 40 cmH₂O. Two TPR devices with known spikes (Draeger Resuscitaire, GE Panda) were compared with handheld Neopuff (NP). Recommended settings for positive end-expiratory pressure (5 cmH₂O), inflation rate of 60/min and gas flow rate 10 L/min were used.

RESULTS

2293 inflations were analysed. Draeger and GE TPR drivers delivered higher mean PIP (Panda 18.9-49.5 cmH2O; Draeger 21.2-49.2 cmH2O and NP 14.8-39.9 cmH2O) compared with set PIP and tidal volumes (TVs) compared with the NP (Panda 2.9-7.8 mL; Draeger 3.8-8.1 mL; compared with NP 2.2-6.0 mL), outside the prespecified acceptable range (±10% of set PIP and ±10% TV compared with NP).

CONCLUSION

The observed spike in PIP over set values with Draeger and GE Panda systems resulted in significantly higher delivered volumes compared with the NP with identical settings. Manufacturers need to address these differences. The effect on patient outcomes is unknown.

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.

A Novel Prototype Neonatal Resuscitator That Controls Tidal Volume and Ventilation Rate: A Comparative Study of Mask Ventilation in a Newborn Manikin

The objective of this randomized controlled manikin trial was to examine tidal volume (V_T) delivery and ventilation rate during mask positive pressure ventilation (PPV) with five different devices, including a volume-controlled prototype Next Step™ device for neonatal resuscitation. We hypothesized that V_T and rate would be closest to target with the Next Step™. Twenty-five Neonatal Resuscitation Program providers provided mask PPV to a newborn manikin (simulated weight 1 kg) in a randomized order with a self-inflating bag (SIB), a disposable T-piece, a non-disposable T-piece, a stand-alone resuscitation system T-piece, and the Next Step™. All T-pieces used a peak inflation pressure of 20 cmH₂O and a positive end-expiratory pressure of 5 cmH₂O. The participants were instructed to deliver a 5 mL/kg V_T (rate 40-60/min) for 1 min with each device and each of three test lungs with increasing compliance of 0.5, 1.0, and 2.0 mL/cmH₂O. V_T and ventilation rate were compared between devices and compliance levels (linear mixed model). All devices, except the Next Step™ delivered a too high V_T, up to sixfold the target at the 2.0-mL/cmH₂O compliance. The Next Step™ V_T was 26% lower than the target in the low compliance. The ventilation rate was within target with the Next Step™ and SIB, and slightly lower with the T-pieces. In conclusion, routinely used newborn resuscitators over delivered V_T, whereas the Next Step™ under delivered in the low compliant test lung. The SIB had higher V_T and rate than the T-pieces. More research is needed on volume-controlled delivery room ventilation.