The Neopuff's PEEP valve is flow sensitive

Oxygen supplementation in the delivery room: T-piece resuscitator cap open or occluded?

OBJECTIVE

Updated neonatal resuscitation guidelines for free-flow oxygen administration with a T-piece resuscitator recommend higher gas flow and an open T-piece cap. We aimed to determine the effect of gas inflow rate and cap occlusion on oxygen delivery through a T-piece resuscitator.

STUDY DESIGN

Using a NeoPuff™ T-piece, oxygen inflow was randomly adjusted from 4 to 10 liters per minute (LPM). Gas outflow and oxygen concentration were measured with the T-piece cap open and occluded. Data were analyzed with repeated measures 2-way ANOVA.

RESULT

Gas outflow was significantly decreased with the T-piece cap open compared with occluded at each inflow rate (p < 0.001). There was no difference in oxygen concentration of the outflow gas.

CONCLUSION

Gas flow from the T-piece is affected by the inflow rate and cap occlusion but oxygen concentration is not. To deliver 5 LPM of free-flow oxygen with the cap open, a minimum of 8 LPM gas inflow is required.

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.

Do we deliver the pressures we intend to when using a T-piece resuscitator?

Background

A T-piece resuscitator (TPR) uses a built-in manometer to set the inflation pressures, but we are not informed what pressures are actually delivered distally. Aim of this study was to measure the proximal and distal pressures under different gas conditions when using a TPR.

Methodology/Findings

A test lung was ventilated using a TPR (PIP 25 cmH₂O, PEEP 5 cmH₂O) with a gas flow rate of 8 L/min. A) Pressure delivered by six different TPRs was tested. To test variability 20 participants were asked to set PEEP and PIP pressures to 25/5 cmH₂O. B) PIP and PEEP were measured proximal and distal of the TPR when using standard tubing or heated tubing with or without a humidifier. In experiment A mean (SD) proximal PIP and PEEP of the TPRs were respectively 20.3 (0.3) cmH₂O (19.9–20.6 cmH₂O) and 4.9 (0.1) cmH₂O. When 20 participants set pressures; PIP 26.7 (0.5) cm H₂O and PEEP 5.9 (0.44) cmH₂O were measured. Experiment B showed that the decrease of PIP between proximal and distal pressures was not clinically significant. However there was a significant decrease of PEEP using the standard tubing (5.1 (0.1) cmH₂O proximally versus 4.8 (0.2) cmH₂O distally; p<0.001) compared to, when using a humidifier with associated tubing and the humidifier turned on, 5.1 (0.1) proximally versus 3.9 (0.2) cmH₂O distally; (p<0.001).

Conclusion/Significance

The accuracy of the built-in manometer of a TPR is acceptable. Most pressures set proximally are comparable to the actual pressures delivered distally. However, when using tubing associated with the humidifier PEEP decreases distally by 1.1–1.2 cmH₂O and users should anticipate on this.

New concepts in neonatal resuscitation

PURPOSE OF REVIEW

There has been a substantial increase in the number of studies of neonatal resuscitation and it is timely to review the accumulating evidence.

RECENT FINDINGS

There have been major changes in the way that newly born infants are managed in the delivery room. Colour is no longer recommended as a useful indicator of oxygenation or effectiveness of resuscitation. Pulse oximetry provides rapid, continuous and accurate information on both oxygenation and heart rate. Resuscitation of term infants should begin with air, with the provision of blended oxygen to maintain oxygen saturations similar to those of term infants requiring no resuscitation. Positive end-expiratory pressure during initial ventilation aids lung aeration and establishment of functional residual capacity. Respiratory function monitoring allows operators to identify factors adversely affecting ventilation, including leak around the face mask and airway obstruction. Clamping of the umbilical cord should be delayed for at least 1 min for infants not requiring resuscitation.

SUMMARY

The International Liaison Committee on Resuscitation guidelines on the management of newborn infants were updated in 2010 and incorporate much of the newly available evidence. The use of intensive care techniques in the delivery room is promising but requires further evaluation. Monitoring techniques and interventions need to be adapted for use in developing countries.