Unexpected at 24,000 Feet

Contributors Dr Toby Shipway and Flight Nurse Jodie Martin return with a little about something that would make any retrievalist sweat – delivering babies in the air. 

A call came into the Logistics Coordination centre from a nurse in a remote health centre, worried about new contractions in a pregnant woman who was 31 weeks pregnant. We decided to take a full retrieval team for the ‘just in case’ scenario.  Afraid of getting caught out, we had a big discussion to make sure we had all the right gear on board the aircraft and what our plan of action would be should we be faced with the rare event of an inflight birth. Why worry though? They’re rare, right?

We retrieved the woman from a remote airstrip and it became evident just after takeoff that she was in established labour. Even after tocolytic therapy, the preterm baby was born at the start of descent into Darwin. No one on the plane will forget the midwife examining the patient, looking up wide-eyed and shouting calmly down the plane ‘its coming out now’.  Never has a pilot descended at such a pace. After initial resuscitation of the baby, both mum and baby did well and were transferred safely to the hospital. Phew.

After this, we started researching how many in-flight births had been registered during CareFlight’s tenure in the Northern Territory (NT). This became the basis for a recent case series publication in the Airmedical Journal.

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The sort of view you don’t get to enjoy when it starts getting imminent.

The Big and Little Numbers

Four cases were found on searching through the database over a four-year period from 2011 to 2015. Over that four-year period there were 1311 retrievals associated with Obstetrics and Gynecology, out of a total number of 15967 retrievals in the NT. This means obstetric and gynecology related retrievals account for approximately 8.2% in our aeromedical retrieval service.

Looking at the obstetric retrievals in more detail, there were 436 cases associated with pre-term labour of which 4 progressed to in-flight births. This equates to an incidence of 0.92% of all women transferred in preterm labour. It is not a common clinical situation.

These numbers are similar to a paper from Ontario, Canada1, which showed an incidence of 2.25% (11 in-flight births from 488 pre-term labour patients over a 5 year period). A paper from RFDS in Western Australia from 20122 showed no in-flight births over a 26-month period, with 500 cases of women at risk of pre-term birth included. Our four cases aren’t the only ones happening in Australia though. There was a preterm birth on an aeromedical aircraft over the Bass Strait recently.

What About Those Cases Then?

Here’s a brief description of each of those 4 cases.

Case one was a 37 year old woman of gestational age 36+5 weeks, gravida 5 para 2. The retrieval was tasked in the early hours at 0010. Take off was at 0050 and contact was made with the patient at 0145 at the airstrip. She was contracting 3:10 at this point. Tocolytics had been administered according to protocol, which was 3 separate doses of nifedipine 20 mg initially, at 30 mins and at 1 hour.  Return takeoff was at 0210 with progression to spontaneous vaginal delivery of the baby at 0245. 10 unit of syntocinon was administered intramuscularly with approximately 300 mL of blood loss measured with delivery of the placenta. Apgars of 61 and 95 were recorded. Both baby and mother were discharged at 3 days from hospital with routine follow-up from the community nurse.

Case two was a 25 year old woman of 31week’s gestation, G2P1 – this was the case from the top.  Again this was an early morning flight, tasking was at 0052 and take off was 0128.  Patient contact was made at 0250, where the patient walked onto the plane contracting 1:10. The clinic team had given nifedipine as per protocol. Return takeoff was at 0300 with progression to spontaneous vaginal delivery at 0400. Apgars were 61 and 85 with the baby needing some supportive ventilation. Mother and baby were transferred to hospital where on assessment in the neonatal unit positive pressure ventilation was stopped. Length of stay for this little one with intrauterine growth retardation was 22 days; there were no complications with the mother.

Case three was a 31 year old woman of 22 week’s gestation, G6P2. This one came up in a previous post as it involved a complicated resuscitation of mother and baby. The midwife was en-route back to home base on another task when the referral call to divert to this case was made. This again was in the early morning with the re-tasking occurring at 0330. On assessment at 0450 the patient was contracting 3:10, and the clinic reported a large clot was passed in clinic. Return takeoff was at 0500, with progression to spontaneous vaginal delivery at 0522. Apgars were recorded as 61 55 510 as neonatal resuscitation was ongoing. The mother delivered the placenta at 0548, which was accompanied by a PPH of 1 L dropping maternal BP to 42/38. Fundal massage and a blood transfusion were started. On landing the retrieval team was met by a ground crew – the neonate was transferred in a separate ambulance with ongoing resuscitation by the Medical Retrieval Consultant and a flight nurse. On reaching the Emergency Department the multi-disciplinary team decided to cease resuscitation of the baby at 0645. The mother received further blood products and stayed in hospital for 4 days.

Case four was a 26 year old woman of 28+5 week’s gestation, G2P1. This was the only retrieval in daytime hours with tasking at 1040 and take off recorded as 1135. The retrieval team went into clinic on arrival, making contact at 1245. On assessment the patient was contracting 1:10. Return takeoff was at 1345 and patient passed a large blood clot at 1410 with rapid progress to spontaneous vaginal delivery at 1418. Apgars recorded were 61 95 and some respiratory support with nasal high-flow was given. The placenta was passed at 1425 and the total blood loss was estimated to be 250 mL. The patient had no documented cardiovascular instability. The patient and baby were transferred to hospital with no further issues. However the baby stayed in hospital for 66 days needing long-term respiratory and feeding support. It was diagnosed with a dilated cardiomyopathy and on follow-up review was listed for a heart transplant.

 

What About the Treatment?

All women received the recommended preterm labour treatment, being intravenous antibiotics and steroid therapy. Three out of four patients received tocolysis – the fourth case did not as the blood clot passed in clinic was deemed a contraindication. It was reported vaginal examinations upon referral were conducted in 3 out of 4 of these cases. Interestingly, the reports of those examinations found the cervix to be closed or an undetermined dilation.  It goes to show that despite our best estimates from a physical examination we need to be prepared that inflight birth may in fact occur, even though it is a rare occurrence.

In transferring women in pre-term labour, the aim is to keep the baby in utero, as the evidence relevant to our setting indicates that in utero transfer is associated with much improved maternal and neonatal outcomes. The NT has a particularly high proportion (10.6%) of preterm births prior to hospital arrival and although multifactorial the large distances are likely to play a significant role.  Prompt retrieval and the involvement of a team with the right skill mix to make a detailed obstetric/midwifery risk assessment would hopefully lessen the chances of inflight birth. But very rare still doesn’t mean never.

Notes:

Here are those other papers again:

McCubbin K, Moore S, MacDonald R. Medical transfer of patients in preterm

labor: treatment and tocolytics. Prehosp Emerg Care. 2015;19:103e109.

and

Akl N, Coghlan EA, Nathan EA, Langford SA, Newnham JP. Aeromedical transfer

of women at risk of preterm delivery in remote and ruralWestern Australia: why

are there no births in flight? Aust N Z J Obstet Gynaecol. 2012;52:327e333.

and of course the trigger paper from our NT experience is here:

Shipway T, Johnson E, Bell S, Martin J, Clark P. A Case Review: In-Flight Births Over a 4-Year Period in the Northern Territory, Australia. Air Med Journal. 2016;315:317-20. 

 

 

 

 

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