Flying and midface fractures: the truth is out there

Abstract

There are no clear, evidence-based guidelines that dictate when it is safe for a patient to fly after sustaining a midface fracture. From January 2006 to December 2009, the Royal Darwin Hospital Maxillofacial Unit had 48 out of 201 patients with an orbital fracture that involved a paranasal air sinus transported by a variety of aircraft to the unit for definitive management. No orbital complications were recorded for the 24% of patients requiring air travel to our tertiary referral centre. Furthermore, there were no recorded deviations from the standard flight plan. We believe that this demonstrates there are no absolute contraindications to flying on a variety of aircraft with a midface fracture, but clinical assessment remains crucial for an informed decision to transport these patients by air.

Fractures involving the midface often involve an adjacent air sinus. In the absence of evidence-based guidelines, expert opinion advocates that such patients avoid flying for a period of 2 weeks after injury, whether the fractures are treated conservatively or operatively. This advice is based on an understanding of the physics of the paranasal sinuses and air travel, and on expert opinion. However, there is no evidence in the current literature to support this advice.

The Royal Darwin Hospital (RDH) is the single tertiary referral centre for all facial trauma in the Northern Territory (NT) of Australia, and provides a service for all victims of facial trauma in an area that covers almost 1.5 million square kilometres. The travel time by road to reach RDH can take over 24 h from some locations, and the roads are impassable during certain parts of the year. Air travel is the most time-efficient manner by which to transport patients in the NT. It is, in some cases, unavoidable as alternate road-based transport forms are rendered impossible by the tyranny of remoteness and due to extreme weather conditions, e.g. floods.

Furthermore, remote clinics may lack the resources to definitively image patients in cases of suspected facial fractures, and travel to RDH must be organized without the benefit of confirmation of the presence of these injuries prior to transfer.

We reviewed all cases of patients who had been flown to the RDH for the management of maxillofacial trauma and who had radiological confirmation of midface fractures. We limited our review to those patients with an orbital fracture and communication into the adjacent sinus, e.g. orbital floor fracture with communication into the corresponding maxillary sinus. We excluded isolated nasal bone fractures that did not involve the paranasal sinuses. In doing so, we aimed to elucidate the effect of flying on patients with midface fractures, and in particular, on those with fractures where there was potential for exertion of a pressure effect from the gas in the adjacent anatomical air space into the orbital cavity.

Materials and methods

Utilizing unit records and the Department’s trauma database, we retrieved the details of all patients who suffered a midface fracture over a 3-year period, between January 2006 and December 2009. These details were cross-referenced with the Patient Accommodation and Travel Service (PATS) records, which is the NT Government’s travel organization for subsidized transport for medical treatment. All patients requiring transport for medical treatment within the NT are entitled to this subsidy. Patients requiring transport for medical treatment interstate are also entitled to this subsidy. The mode of transport can be either by road or by air travel, and is determined by the PATS team based upon the availability of the various transport modes. There are remote locations where travel by road (either by car or bus) is not possible due to distance or lack of a sealed road.

The data from the PATS records were collated by a single member of the research team.

We reviewed the charts, electronic notes, and radiology of the relevant patients. In particular, we looked at the following parameters: (1) the location of the midfacial injury. (2) Whether patients arrived at RDH with any new complications, including orbital emphysema, visual loss, and sinus pain. The complications were recorded only if they occurred during or after the flight, and were not present prior to the flight. (3) Whether patients had symptoms during the flight, at altitude, which required a change in flight path, altitude, or any other intervention.

We also recorded the air services utilized by the PATS to transport patients to Darwin. We then performed an internet search to determine the specific aircraft used by the respective air services, and we looked at the maximum altitude capabilities of the aircraft.

The inclusion criteria for this study were: patients with orbital fractures that involved the adjacent air sinus and who were flown with their fresh fractures for treatment.

Results

Two hundred and one patients presented to the RDH Maxillofacial Unit with orbital fractures that involved the adjacent air sinus during the 3-year period from January 2006 to December 2009. Forty-eight of these patients were transported by air to the RDH. This represents 24% of all patients with orbital fractures. A chart review of the 48 patients was performed and any complications entered into a Microsoft Excel spreadsheet. No further information about the patients was recorded.

The minimum delay recorded for a patient to be assessed and managed prior to air travel to the RDH is approximately 2 h. This includes the time required for assessment and initial management of the patient, discussion with the ‘on call’ maxillofacial registrar, and organization of flights. This time delay can vary significantly and is dependent on a variety of factors, including departure schedule, priority (in the case of aeromedical retrieval services), location of an escort for the patient, and extreme weather.

The average duration of flight during transport varies depending upon the type of flight (e.g. aeromedical retrieval or commercial, helicopter, or fixed-wing aircraft). The longest flight was from Port Keats to Darwin, totalling an approximate flight time of 5 h on a fixed-wing aircraft ( Table 1 ).

Table 1
Locations, distance by road, average flight time, and number of patients transported from the location to the RDH.
Location Distance by road; Google Maps a Average flight time Number of patients
Alice Springs 1497 km 2 h 14
Gove 1031.6 km 1.5 h 10
Katherine 316.1 km 1 h 6
Maningrida 511.1 km 1 h Maningrida; 3 h Pearl Aviation 4
Port Keats/Wadeye 393.6 km 1 h Pearl Aviation; 5 h Murin 3
Daly River 222 km 1 h 2
Borroloola 970 km Not recorded b 2
Groote Eylandt Requires sea crossing 1.75 h 2
Gapuwiyak 885 km Not recorded b 1
Milingimbi Requires sea crossing 1 h 1
Elcho Island Requires sea crossing 2 h total; 2 flights of 1 h duration 1
East Arnhem 636 km Not recorded b 1
MacArthur Mines 1016 km Not recorded b 1
Total 48
RDH, Royal Darwin Hospital.

a Available at: maps.google.com.au .

b Not recorded on the Patient Accommodation and Travel Service system due to aeromedical retrieval or chartered flights. This information is not publicly available.

The three most common aircraft utilized during the study period were the Boeing 717, Beechcraft Super King Air, and the Metroliner Fairchild Metro 23. All of these craft have pressurized cabins and the maximum altitude that the aircraft can reach ranges from 7600 to 11,300 m ( Table 2 ). In addition to these aircraft, CareFlight, a medical retrieval organization, utilizes unpressurized helicopters in both patient rescue and transfer scenarios. The maximum altitude flown by these aircraft is 4572 m during the period of observation.

Table 2
List of aircraft flown in Northern Territory and their maximum altitudes.
Company Aircraft Maximum altitude
Qantas Boeing 717-220 11,300 m (37,100 ft)
Pearl Aviation B200 King Air 10,668 m (35,000 ft)
Metro 23 Airliner 7600 m (25,000 ft)
RFDS Pilatus PC 12 9144 m (30,000 ft)
AirNorth Embraer 170 11,900 m (39,000 ft)
Embraer EMB 120 Brasilia 9144 m (30,000 ft)
Fairchild Metro 23 7620 m (25,000 ft)
CareFlight Helicopter, Kawasaki BK117 B2 4572 m (15,000 ft)
Helicopter, Agusta A109E 6096 m (20,000 ft)
Helicopter, Bell 412EP 6069 m (20,000 ft)
B200 King Air 10,668 m (35,000 ft)
Vincent Aviation Beechcraft 1900 7600 m (25,000 ft)
SAAB 340 9450 m (31,000 ft)
BAe146 8840 m (29,000 ft)
Aboriginal Air Pilatus PC 12 9144 m (30,000 ft)
Murin Unavailable Unavailable
Chartered unspecified Unavailable Unavailable
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Jan 20, 2018 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Flying and midface fractures: the truth is out there
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