Neonatal transports—risks and opportunities

doi:10.4236/ojped.2011.14013

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Open Journal of Pediatrics, 2011, 1, 45-50

doi:10.4236/ojped.2011.14013 Published Online December 2011 (http://www.SciRP.org/journal/ojped/

OJPed

)

Published Online December 2011 in SciRes. http://www.scirp.org/journal/OJPed

Neonatal transports—risks and opportunities

Alf Meberg1*, Thor W ill y Ruud Hansen2,3

1Department of Paediatrics, Vestfold Hospital Trust, Tønsberg, Norway;

2Department of Neonatology, Women & Children’s Division, Oslo University Hospital HC—Rikshospitalet, Oslo, Norway;

3Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.

Email: *[email protected]

Received 22 September 2011; revised 30 October 2011; accepted 3 November 2011.

ABSTRACT

Aim: To assess the need for and quality of neonatal

transports. Material and methods: Prospective ob-

servational study of consecutive transports from a

level II neonatal unit. Results: 500 transports were

undertaken 1982-2010 in 445 patients, representing

0.7% of liveborn infants (n = 61,450). Indications

were congenital malformations in 223 (45%), pre-

maturity/respiratory distress syndrome (RDS) in 87

(17%), and other conditions in 190 (38%). For pa-

tients ventilated during transport (n = 121) mean

pCO2 was improved at arrival, and for spontaneously

breathing patients mean pH, pCO2, and base excess

(p < 0.05). After establishing a local respirator pro-

gramme from 1989, transports for prematurity/RDS

declined from 3.4 per 1000 live born infants in

1982-1988 to 0.8 per 1000 in 1989-2010 (p < 0.0001),

and night-time transports (departure between 22.00

pm - 06.00 am) declined from 24/119 (20%) to 38/381

(10%) (p = 0.003). Technical mishaps or severe clini-

cal deterioration occurred in 16 (3%) of the trans-

ports. Conclusions: Neonatal transport carries risks,

but also an opportunity for further stabilization and

improvement. A local respirator programme reduced

the need for transfer of premature infants with RDS

as well as for transports during night-time.

Keywords: Acidosis; Hypothermia; Newborn Infants;

Transport

1. INTRODUCTION

In an unselected population of newborn infants 1% - 2%

are estimated to be in need of advanced care in a level III

neonatal unit [1]. Postnatal transports of such patients

from level II units may cause discontinuity in monitoring

and treatment, with increased risk for deterioration [2,3].

A high-quality neonatal transport system thus is a key

element in regionalized perinatal care programmes [4].

The aim of the present study was to assess the quality

of 500 consecutive transports from a level II neonatal

unit in infants born 1982-2010, as judged from clinical

data, laboratory tests and technical mishaps. Our hy-

pothesis was that the transit time was an opportunity for

further stabilization with clinical and laboratory im-

provement, and that a local ventilator treatment pro-

gramme (established 1989) would cause a decline in the

need for transports, especially for preterm infants with

respiratory distress syndome (RDS).

2. MATERIAL AND METHODS

2.1. Population

Vestfold Hospital serves a population of 220,000 inhabi-

tants in the County of Vestfold, Norway. The hospital

has the only delivery and neonatal unit in the county,

where 90% of the pregnant women deliver their babies

(about 2000 each year). The neonatal unit is a level II

unit undertaking some level III tasks (such as short term

ventilator treatment, established from 1989). In threat-

ened preterm delivery before week 28 of gestation, and

when severe fetal malformations have been diagnosed,

the pregnant woman is transferred to the regional hospi-

tal for delivery. Steroid treatment to promote fetal lung

function in preterm delivery was introduced 1991, and

surfactant treatment for severe RDS from 1992.

During the 29-year period 1982-2010 data from 500

consecutive transports from the neonatal unit were re-

corded prospectively (clinical and laboratory data, tech-

nical mishaps). The study was approved by the regional

committee for medical research ethics.

2.2. Transport System

The vast majority of transports were by ground vehicle

(ambulance) to the regional hospital, a distance of 100

km. A Dräger Medical transport incubator 5400 with a

Babylog 2000 respirator and monitoring equipment in-

cluding electrocardiogram, respirogram, continuous rec-

tal temperature sensor and pulse oximeter was used.

A. Meberg et al. / Open Journal of Pediatrics 1 (2011) 45-50

Blood samples and X-ray pictures were taken at depar-

ture for final stabilizing procedures at the discretion of

the attending pediatrician, and at arrival, especially in

patients recognised as unstable or potentially unstable.

Transports were organized and carried out by per-

sonell from the local neonatal unit after necessary diag-

nostic evaluation and stabilizion. Depending on the cli-

nical condition, transports were attended by a paediatri-

cian (unstable, sick patients) or neonatal nurse (stable

patients). The organizing, equipment (except for pulse

oximetry introduced 1986) and guidelines for transports

remained the same during the whole period. Nasal con-

tinuous positive airway pressure (CPAP) was not used.

2.3. Statistics

Statistical calculations were done by paired two group

t-test, Fisher’s exact test, and chi-sqare-test. The com-

puter programme StatView II, Abacus Concepts, Berkely,

USA was used for the analyses. A p-value < 0.05 was

considered statistically significant.

3. RESULTS

3.1. Need for Transports

During the 29-year period 1982-2010 61,450 infants

were born alive at the hospital. Of these 445 (0.7%) were,

following admission to the neonatal unit, transferred to

another hospital. 404 (91%) were transported to the re-

gional/national hospital for specialized care, and the re-

maining 41 transferred to their home hospital in other

provinces in Norway or abroad. 37 patients were trans-

ported more than once (range 2 - 4), accounting for a

total of 55 retransports. Thus, a total of 500 transports

were carried out, 466 (93%) by ambulance, 22 by taxi

(4%), 9 (2%) by aeroplane, and 3 (0.6%) by helicopter.

184 transports (37%) occurred during the first 24

hours after birth, and an additional 120 (24%) later on

the first week of life. Figure 1 shows the time of day of

departure. Most of the transports departed in the morn-

ing, while 62 (12%) left the hospital during the night-

time (between 22.00 pm and 06.00 am). The percentage

of night-time transports, after establishing a local venti-

lator programme 1989, declined from 24/119 (20%) for

infants born 1982-1988 to 38/381 (10%) for infants born

1989-2010 (p = 0.003).

Table 1 shows the number of transports for malforma-

tions, prematurity/RDS and other conditions. The inci-

dence of transports was unchanged. 119 transports (0.8%)

in 14,271 live born infants were undertaken 1982-88

compared to 381 (0.8%) in 47 179 infants born in 1989-

2010 (p = 0.76). Transports of infants with congenital

malformations were done in 48/14,271 (3.4 per 1000)

and 175/47 179 (3.7 per 1000) respectively in the two

periods (p = 0.55). There was a highly significant reduc-

Figure 1. Time for departure from the neonatal unit in 500

transports.

tion in transfer of preterm infants with RDS, from 48/14

271 (3.4 per 1000 live born) 1982-1988 to 39/47 179

(0.8 per 1000) born 1989-2010 (p < 0.0001). For the

other conditions respectively 23/14 271 (1.6 per 1000)

and 167/47,179 (3.5 per 1000) were transported (p =

0.0003). This increase was partly caused by more pa-

tients belonging to other provinces who needed transfer

to their home hospitals after birth and initial care in our

hospital, respectively 4/14 271 (0.3 per 1000) 1982-88

and 37/47,179 (0.8 per 1000) 1989-2010 (p = 0.04). Re-

transports to the regional hospital also increased signifi-

cantly from 3/14,271 (0.2 per 1 000) to 52/47,179 (1.1

per 1000) (p = 0.001). In 121 transports (24%) the pa-

tient was mechanically ventilated.

3.2. Temperature and Laboratory Tests

Table 2 shows body temperature and laboratory values

before departure and at arrival where paired values were

available. No significant change in mean body tempera-

ture occurred, while blood glucose increased and hemo-

globin concentration decreased significantly (p < 0.05).

For the acid-base parameters significant changes oc-

curred for mean pH, pCO2 and base excess. In patients

on ventilator during transport (n = 121) pH was 7.26 ±

0.17 (mean ± SD) and 7.29 ± 0.16 (p = 0.12), pCO2 7.6

± 3.5 kPa and 6.9 ± 3.5 kPa (p = 0.01), and BE −2.6 ±

6.9 mmol/l and −3.3 ± 6.7 mmol/l (p = 0.26) respec-

tively at departure and arrival. The corresponding values

in patients breathing spontaneously during transport

were pH 7.34 ± 0.08 and 7.36 ± 0.08 (p = 0.006), pCO2

6.3 ± 1.4 kPa and 5.9 ± 1.3 kPa (p = 0.0001), and BE

−2.3 ± 4.5 mmol/l and −0.8 ± 5.0 mmol/l (p = 0.046). In

patients with critical heart defects given prostaglandin E1

(PGE) infusion during transport (n = 30) pH was 7.29 ±

0.13 and 7.34 ± 0.10 (p = 0.05), pCO2 7.1 ± 2.3 kPa and

5.6 ± 1.3 kPa (p = 0.002), and BE −3.8 ± 5.0 mmol/l and

−3.2 ± 4.1 mmol/l (p = 0.68) respectively at departure

A. Meberg et al. / Open Journal of Pediatrics 1 (2011) 45-50

OJPed

Table 1. Indications for 500 consecutive transports 1982-2010.

1982-1988 1989-2010 Total

n % n % n %

Malformations

- heart

- gastrointestinal tract

- central nervous system

- other

40 175

46 223

Prematurity/RDS 48 40 39a 10 87 17

Miscellaneous 23 19 167a 44 190 38

Total 119 100 381 100 500 100

ap < 0.05; statistically significant difference from 1982-1988; RDS = respiratory disress syndrome.

Table 2. Body temperature and laboratory tests before departure and at arrival.

Before departure At arrival

n Mean Range Mean Range p-value

Tp (˚C) 293 36.9 33.5 - 38.5 36.9 34 - 39.7 0.769

Glucose (mmol/l) 226 4.6 0.3 - 16.7 5.1 0.5 - 19.9 0.006

Hemoglobin (g/100 ml)a 188 18.1 11 - 26.2 17.1 10.3 - 27.1 0.0001

pH 310 7.31 6.66 - 7.58 7.33 6.74 - 7.63 0.005

pCO2 303 6.7 2 - 20.3 6.2 2.7 - 19.2 0.0001

Base excess (mmol/l) 309 −1.2 −24.4 - 20 −1.7 −25 - 19.1 0.038

aTransport before 72 hours after birth.

and arrival.

Figure 2 shows the number of infants with extreme

values before departure and at arrival. Although there

appeared to be a trend towards more patients with hypo-

and hyperthermia, hyperglychemia, anemia (only cases

transported <72 hours of age were included to minimize

the interference from the physiological decline in hemo-

globlin concentration), alkalosis, hypocapnea, and major

base deficit at arrival, the numbers were not significantly

different from the numbers with extreme values at de-

parture (p > 0.05). Some patients with extreme values at

departure also had extreme values at arrival. Two se-

verely asphyxiated infants were intentionally hypother-

mic both at departure and arrival. Ten out of 18 patients

(56%) with body temperature <36˚C at arrival had low

birth weight (<2500 g). Of 14 patients with severe aci-

dosis (pH < 7.10) at arrival five were transported for

prematurity/RDS, three for persistent pulmonary hyper-

tension, two for critical heart defects, and one each for

group B streptococcal septicemia, diaphragmatic hernia,

asphyxia and Potter syndrome.

3.3. Technical Mishaps-Clinical Complications

In 16 transports (3%) severe technical failure or clinical

complications were recorded. Accidental extubation,

tube dislocation into the right main bronchus or tube

dislocation from the connector occurred in eight patients,

7% of the patients who were ventilated. In two patients

umbilical catheter complications occurred (bleeding be-

cause of catheter dislocation). In one transport the respi-

rator failed, in one the oxygen supply ran out, and in one

the ambulance broke down. One case developed pneu-

mothorax (mechanically ventilated during transport) and

in two spontaneously breathing infants severe apnoea

requiring manual mask ventilation occurred.

3.4. Mortality

No infant died during transport, however, 14 died within

24 hours after arrival, accounting for a transport related

mortality of 3%. Six of these had letal malformations. A

total of 58 infants (13%) died before discharge from the

regional hospital. Mortality declined from 27/116 infants

(23%) transported 1982-1988 to 31/329 (9%) transported

1989-2010 (p = 0.0001).

4. DISCUSSION

4.1. Need and Time for Transports

Of all live born infants 0.7% were transported to another

A. Meberg et al. / Open Journal of Pediatrics 1 (2011) 45-50

Figure 2. Number of infants with extreme values for body temperature, blood glucose, hemoglobin concen-

tration (transports before 72 hours of age) and acid-base values before departure and at arrival.

hospital, of whom more than 90% to a regional hospital

for advanced diagnostic procedures and therapeutic in-

terventions. If in utero transports from the population are

added, 1% of newborn infants were in need of treatment

at the regional hospital (A Meberg, upublished data).

This is in accordance with estimated needs for level III

care in an unselected population of newborns [1]. How-

ever, the need for postnatal transports from level II neo-

natal units may vary according to local resources (ability

to undertake selected level III tasks) and the quality of

obstetric programmes to select high-risk pregnancies for

ante natal transfer (maternal disease, fetal disease or

malformations).

Most of the transfers occurred soon after birth, more

than 1/3 during the first 24 hours and 2/3 during the first

week. Infants with congenital malformations constituted

the largest group. Although antenatal detection of such

conditions has improved in recent years, with possibility

for in utero transfer, the impact on postnatal transports

was not significant. A substantial percentage of severe

congenital malformations are still diagnosed postnatally.

For preterm infants with RDS, however, a significant

decline in transfer needs occurred after establishing a

local ventilator treatment programme. Prenatal steroid

treatment and surfactant in severe RDS most probably

also have contributed to this [5]. At the same time the

demand for night-time transports was halved. A local

respirator programme provides opportunities for better

stabilization of the patient, and allocation to day-time

transportation, when resources for transfer are more op-

timal.

The increasing number of infants transferred to their

home hospitals may be an indicator for more cooperation

between health regions. An increase of infants in need of

more than one transport indicates a more dynamic inter-

action between the regional and the subregional hospital.

4.2. Clinical and Laboratory Results

The present study emphasizes the risk for clinical and

laboratory deterioration of infants undergoing transport

(Figure 2). A higher blood glucose level at arrival may

be an indicator of stress, and decline in hemoglobin con-

centration may represent fluid overload or blood loss.

On the other hand, significant normalization of acid-base

parameters shows that transferral may also be an oppor-

tunity for further stabilization and improvement. This

was well demonstrated in the subgroup of infants with

critical heart defects who received PGE infusion. Im-

proved clinical condition of newborns at the end of

transfer has also been found in other studies [6,7].

A. Meberg et al. / Open Journal of Pediatrics 1 (2011) 45-50 49

Most of the patients with hypothermia (body tem-

perature <36˚C) at arrival were low birthweight infants,

caused by insufficient temperature regulation and in-

creased heat loss because of a large body surface to

weight ratio in these patients. Our experiences are in

agreement with other studies [8]. Temperature monitor-

ing, best performed continuously with a rectal probe,

thus is an important procedure in neonatal transports.

There was a trend for more infants with extreme val-

ues for body temperature, blood glucose, hemoglobin,

and acid-base parameters at arrival (Figure 2). It is a

matter of concern that some patients with extreme values

at departure also had extreme values at arrival. This sug-

gests insufficient stabilization, or that the condition

could not be stabilized. When a specialized retrieval

team carries out the transport, the quality of transports

has been shown to be improved compared to local ad

hoc teams [9,10]. A special challenge is pulmonary hy-

pertension, causing severe hypoxia and metabolic acido-

sis. The risk for death or sequelae is high in these pa-

tients, who may need ventilation with nitric oxide to

reduce pulmonary vascular resistance [11] or extractor-

poral membrane oxygenation to ensure oxygenation [12].

Few hospitals have the possibility to provide such treat-

ment during transport, and will need help from sentral-

ized transport systems with advanced technology.

4.3. Technical Mishaps

Technical errors occurred in some of the transports. This

emphasizes the importance of a high-quality work with

focus on technical details, especially in the pretransport

stabilization period. Proper fixation of the tracheal tube,

X-ray control of tube position and necessary correction

before departure, sedation of active infants (e.g. when

mechanically ventilated) are important points in order to

avoid tube dislocation. The same principles apply for

umbilical vessel catheters.

4.4. Mortality

The transport-related mortality (dead during the first 24

hours after arrival) was low (3%), with nearly half dying

from letal malformations. Better diagnostics could pos-

sibly have avoided some of these futile transports.

A considerable decline in mortality of transported in-

fants occurred without contemporary increasing mortal-

ity in the referring hospital (A Meberg, unpublished

data). The reason for this is multifactorial, reflecting

progress of neonatal care. Better organization of trans-

ports, and better stabilization and treatment of the pa-

tients are important factors. An indicator for this may be

the reduced percentage of night-time transports follow-

ing improvements in the local intensive care programme.

However, in spite of high quality postnatal transports, in

utero transfer is, when possible, the better choice [13,

14].

5. CONCLUSIONS

Neonatal transport carries risks, but also an opportunity

for further stabilization and improvement. A local respi-

rator programme reduced the need for transfer of pre-

mature infants with RDS as well as for transports during

night-time.

6. ACKNOWLEDGEMENTS

The study was supported by a grant from Vestfold Hospital Trust.

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