Establishing ventilation in the delivery room: T-piece resuscitator versus self-inflating bag

MANUSCRIPT CITATION

Szyld E, Aguilar A, Musante GA, et al. Comparison of devices for newborn ventilation in the delivery room. J Pediatr 2014;165:234-9. PMID 24690329

REVIEWED BY

Elizabeth Foglia, MD
Instructor in Pediatrics
Division of Neonatology
Children’s Hospital of Philadelphia

TYPE OF INVESTIGATION

Therapeutics

QUESTION

In infants ≥ 26 weeks gestation who require positive pressure ventilation (PPV) after birth during neonatal transition, which device: self-inflating bag (SIB) versus T-piece resuscitator (T-piece), more effectively establishes lung ventilation, indicated by heart rate (HR) ≥100 beats per minute (bpm) at 2 minutes of life?

METHODS

  • Design: Cluster randomized 2-period crossover trial. Cluster design chosen for ‘ethical reasons’. Clinicaltrials.gov Identifier NCT00443118.
  • Allocation: Initial order of intervention randomly computer-generated by study statistician. Cross-over after each 50 patients enrolled per site, initially with interval “washout period” where training given on use of the alternate device.
  • Blinding: Unblinded for providers in the delivery room and assessors of primary outcome and delivery room secondary outcomes. Blinding unclear for assessors of hospital-based outcomes.
  • Follow-up period: Until hospital discharge, or at least until 36 weeks postmenstrual age for infants <32 weeks gestational age (GA) and until 28 days of life for infants ≥32 weeks GA.
  • Setting: 11 centers from 5 countries (Argentina, Chile, Peru, Italy, and USA)
  • Patients: 1,032 newborns ≥ 26 weeks GA receiving PPV at birth with a facemask.   Exclusion criteria included infants requiring immediate endotracheal intubation at birth, presenting with a major congenital malformation, or members of a multiple birth.
  • Intervention: At each site, providers were trained in the use of the first randomly assigned device: T-piece or SIB. Fifty infants were then enrolled and treated with that device. During a subsequent washout period, the health team was trained in the use of the alternative device. Fifty subjects were then enrolled and treated with the alternative device.
  • Outcomes:
    • Primary outcome: Proportion of newborns with HR ≥100 bpm at 2 minutes of life.
    • Secondary delivery room outcomes: Time to HR ≥100 bpm, time to initiation of spontaneous breathing, oxygen saturation at 2 minutes of life, intubation after mask PPV failure, chest compressions or medication use, 1 and 5 minute Apgar scores, air leaks, and maximum ventilation pressures and FiO2
    • Secondary hospital outcomes: Air leaks, use and duration of oxygen administration, duration of mechanical ventilation and/or continuous positive airway pressure, hypoxic ischemic encephalopathy, bronchopulmonary dysplasia (BPD)
  • Analysis and Sample Size: Estimated approximately 5% of newborns require PPV for resuscitation at birth. The sample size assumed 50 patients for each center–period combination and a proportion of newborns with HR <100 bpm at 2 minutes after cord clamping of 0.8: For 80% power and alpha of 0.05 (2-sided), at least 10 centers were needed to detect a difference of 0.1.
  • Patient follow-up: 1027/1032, (99.5%) of randomized infants included in primary analysis.

MAIN RESULTS:

Results summarized in table.

PRIMARY ANALYSIS
Outcome T piece (n=511) SIB (n=516) OR (95%CI) P value
Primary outcome:HR ≥100 bpm at 2 minutes 94% 90% 0.65 (0.41, 1.05) 0.08
Intubation in the delivery room 17% 26% 0.58 (0.4, 0.8) 0.002
Peak inspiratory pressure, mean +/- SD (cm H2O) 26 +/-2 28 +/-5 N/A <0.001
POST-HOC SUBGROUP ANALYSIS OF VLBW INFANTS        
Outcome T piece (n=85) SIB (n=110) OR (95%CI) P value
HR ≥100 bpm at 2 minutes 88% 76% 0.43 (0.19, 0.95) 0.037
Intubation in the delivery room 53% 69% 2.01 (1.12, 3.60) 0.019
BPD 25% 40% 2.03 (1.09, 3.79) 0.036

Table: Primary and post-hoc analysis of trial outcomes

Abbreviations: bpm, beats per minute; BPD, bronchopulmonary dysplasia; CI, confidence interval; HR, heart rate; OR, odds ratio; SIB: self-inflating bag; SD, standard deviation; VLBW, very low birthweight.

CONCLUSION:

There was no significant difference between the T-piece and SIB in establishing ventilation, as assessed by heart rate. However, the T-piece was associated with lower rates of intubation in the delivery room.

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COMMENTARY:

Establishing effective ventilation is the cornerstone of neonatal resuscitation. 1 Positive pressure ventilation (PPV) can be delivered via a self-inflating bag, flow-inflating bag, or T-piece resuscitator. Although the T-piece is more effective at delivering targeted peak pressures and positive end expiratory pressure (PEEP) in manikins2,3 and in a small clinical study,4 no device has been shown to be superior with regards to clinical outcomes in the delivery room.

The Delivery Room Ventilation Devices (DVD) trial was designed to determine whether the T-piece or SIB is more effective at establishing ventilation after birth, using the clinical indicator of HR ≥100 bpm at 2 minutes of life. The primary outcome did not significantly differ between intervention groups. Yet in the T-piece group, peak inspiratory pressures were lower and less variable, and significantly fewer infants were intubated in the delivery room. Finally, in post-hoc analysis of very low birth weight infants (VLBW), a higher proportion of infants in the T piece group had HR ≥100 bpm at 2 minutes while significantly fewer were intubated in the delivery room or developed BPD.

The study has limitations. Clinical providers’ prior familiarity with a given device may have influenced the quality of PPV performed. The primary outcome, HR, was recorded from the pulse oximeter in only 69% of infants. The remaining HR assessments were made by auscultation, which is notoriously inaccurate.5 Next, providers followed international resuscitation guidelines, but the decision to intubate in the delivery room remains influenced by provider factors. Further, a study team member recorded peak inspiratory pressures from visual assessment of the manometer during PPV; this may have introduced imprecision and bias. Last, the analysis of VLBW infants was performed post-hoc and as authors themselves agree should be interpreted cautiously.

Despite these limitations, the study provides evidence that PPV performed with the T-piece resuscitator is less injurious to the lung. Positive end expiratory pressure (PEEP) helps facilitate clearance of fetal lung fluid and maintain the functional residual capacity (FRC).6 Pulmonary function measurements during PPV indicate that the T-piece delivers significantly more PEEP and less variable peak pressures than the SIB.4 The T-piece may better facilitate lung recruitment by improving PEEP delivery (reducing atelectrauma), delivering lower and less variable peak pressures (reducing volutrauma), and eventually decreasing the need for endotracheal intubation. The potential impact of delivery room management on long-term respiratory outcomes in preterm infants was reviewed as an accompanying editorial to this trial and the Breathings Outcomes Study. 7

Future clinical studies should define the relationship between the characteristics of PPV (such as measured PEEP, peak pressures, and tidal volumes) during neonatal transition and respiratory outcomes in preterm infants. Meanwhile, the Delivery Room Ventilation Devices trial results do not demonstrate either the SIB or T-piece to be more effective in establishing ventilation after birth for all comers, based on the surrogate measure of HR. However, the study findings do suggest the T-piece to be a safer device for ventilation, particularly for preterm infants.

REFERENCES

  1. Kattwinkel J, Perlman JM, Aziz K, et al. Neonatal resuscitation: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Pediatrics 2010;126:e1400-13.
  2. Hawkes CP, Ryan CA, Dempsey EM. Comparison of the T-piece resuscitator with other neonatal manual ventilation devices: a qualitative review. Resuscitation 2012;83:797-802.
  3. Dawson JA, Gerber A, Kamlin COF, Davis PG, Morley CJ. Providing PEEP during neonatal resuscitation: which device is best? J Paediatr Child Health 2011;47:698-703.
  4. Dawson JA, Schmölzer GM, Kamlin COF, et al. Oxygenation with T-piece versus self-inflating bag for ventilation of extremely preterm infants at birth: a randomized controlled trial. J Pediatr 2011;158:912-8.e1-2.
  5. Kamlin COF, O’Donnell CPF, Everest NJ, Davis PG, Morley CJ. Accuracy of clinical assessment of infant heart rate in the delivery room. Resuscitation 2006;71:319-21.
  6. Hooper SB, Siew ML, Kitchen MJ, te Pas AB. Establishing functional residual capacity in the non-breathing infant. Semin Fetal Neonatal Med 2013;18:336-43.
  7. Foglia EE, Kirpalani H, DeMauro SB. J Pediatr. Long-term respiratory morbidity in preterm infants: is noninvasive support in the delivery room the solution? United States2014:222-5.