Can newborn twins be transported on a single ventilator?

By Lorraine L. Janeczko

NEW YORK (Reuters Health) -- A highly specialized neonatal transport service can safely transport newborn twins who need respiratory support together, according to a new retrospective audit of practice from Italy.

In the authors' experience, "the simultaneous transport of twin newborns who need respiratory support is feasible, safe, and effective," they say.

In email to Reuters Health, lead author Dr. Carlo Bellini posed the question: "Should we leave a twin in a peripheral hospital without skilled assistance for hours, or should an experienced and highly skilled team simultaneously transport both twins?"

"While it is highly unlikely that two adults could be considered similar enough to allow simultaneous ventilation -- twin infants of, for example, 30 weeks gestational age, can be expected to have very similar lung conditions," he said.

Dr. Bellini and his colleagues reviewed 3,400 medical charts over sixteen years from the Neonatal Emergency Transport Service (NETS) of the Gaslini Children's Hospital, the main pediatric hospital in Italy and the sole tertiary neonatal intensive center in the region. Dr. Bellini is director of the NETS there.

They reviewed the data of twin infants with respiratory distress syndrome (RDS) who had received respiratory support including nasal continuous positive airway pressure (nCPAP) or mechanical synchronized intermittent positive pressure ventilation (SIPPV) from a single ventilator during transport equipped with a T-shaped connector that split the air flow to both infants.

Each pair of twins was intubated using the same-sized endotracheal tube (2.5- or 3.0-mm internal diameter). Physicians and nurses skilled in neonatal resuscitation and stabilization procedures monitored the infants and the ventilator settings.

NETS transported 46 pairs of twins, with a median gestational age of 31 weeks and a median body weight of 1,770 g. Overall, nCPAP was given to 30 of 46 pairs (all ground transports) and SIPPV was used in 16 of 46 (eight ground transports and eight air transports).

No newborns received endotracheal surfactant before the transport. All eight pairs transported by helicopter were treated by SIPPV. The median transport time was 2 hours 20 minutes by ground and 30 minutes by air.

As reported online in the November issue of Air Medical Journal, the babies' pCO2, base excess (BE), and transport risk index of physiologic stability (TRIPS) scores recorded at the time of NETS arrival were significantly better than matched values recorded at NETS departure (p<0.05).

There were no significant differences in the transport of twin newborns compared with matched singleton newborns transferred using a single ventilator/nCPAP device in collected blood gas results, pH and BE values, blood saturation, and body temperature, the authors said.

Nor did they see any significant adverse events during nCPAP treatment or during SIPPV in either the twins or the singletons. (The authors do not present the comparative data, which is available "upon request.")

The authors cautioned, "In many instances, lung dynamics may be similar between twins, although in the immediate postnatal period they may not be. Therefore, the two twins may require different ventilator approaches. We are aware that asynchrony between the ventilator and one of the infants could lead to excessive pressure being delivered to the sibling."

Dr. Debra Teasdale, dean of the Faculty of Health and Social Care of Canterbury Christ Church University in Canterbury, Kent, UK, told Reuters Health in an email, "The study highlights a pragmatic approach to care provision which appears to be limited by the economic situation locally and does not reflect current practice worldwide."

She had concerns about the study and the lack of details provided by the authors.

"What is clear is that the majority of twins received CPAP but this is referred to as nCpap, so it is unclear if all babies were actually intubated, or if short-prong CPAP was used," she said.

Also, she said, "It is helpful to see the comparison against singleton transfers, but there is no data supplied, which leaves questions regarding the validity of such a claim that the data suggested outcomes were comparable," she said.

"In addition, this was on eight sets of twins over a significant time period, with no indication of variables, such as the staff. This small sample size is problematic and cannot support generalization. A prospective trial would be required."

Dr. Rich Branson, registered respiratory therapist and professor of surgery at the University of Cincinnati, added in an email, "The real issues have to do with how wise it is to do this. The T-piece extends to each patient with a piece of tubing. This tubing is 'deadspace' and the infants re-breathe the gas in the tubing that contains their exhaled carbon dioxide. This means that each infant has to breathe more often (faster respiratory rate) or deeper (larger tidal volume) to eliminate this additional carbon dioxide."

"The authors mention that different patient sizes can present a problem. When you connect a ventilator to two test lungs or to two patients, and the ventilator is at a given setting, the distribution of gas depends on the lung characteristics. If both lungs are the same (highly unlikely), the gas is distributed evenly. However, if one lung is stiffer than the other, the stiff lung gets a smaller amount of gas and the softer (more normal) lung gets more gas. This is important because too large a volume of gas can injure the lung and too small a volume will not allow for appropriate gas exchange," he said.

"I think this is still a technique that can be used when necessary, as the authors say, by experienced and trained personnel. But this is not an in-depth study of how much gas went to each infant or how outcomes might have been affected. This technique has been used by the authors but not evaluated scientifically for safety and efficacy," he said.

SOURCE: http://bit.ly/1fYJoju

Air Medical Journal 2013.

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