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Certainly, Darren's view is borne out by the Bolkow 105 flown in Lincolnshire. The requirement to reverse the patient's orientation would place them face up in a tunnel, and render all but their knees and ankles inaccessible. By definition, helicopters are difficult working environments: I feel we are more likely to prevent secondary injury by good airway control, adequate oxygenation, and maintenance of adequate cerebral perfusion pressure. Incidentally, we seem to be coming across more and more "Flight Phobic" patients. Any anecdotes? -----Original Message----- From: Darren Walter <[log in to unmask]> To: acad-ae-med <[log in to unmask]> Date: 06 October 1998 10:51 Subject: Head First >Simon Carley wrote: > >>Helicopters fly forward by angling their rotors forward thereby creating a >>component of their lifting force rearward. Initially this causes the body >>of the aircraft to tip nose down. In level flight the body of the helo >>balnces forward and starts to become horizontal again. Does this happen >>when gaining altitude? It is sadly a little time since I have flown and I >>cannot remember. If this is the case then (as all the helo's I know carry >>the patient head first) the simple act of putting the patient (effectivly >>head down) may increase ICP. Any helo persons out there to give this some >>thought? > >>On a separate thought. Theoretically placing a head injured patient head >>first in an ambulance is less advantageous than feet first as decelaration >>forces in an ambulance are greater than accelaratory forces. Going head >>first should produce more profound and greater rises in venous pressure >>(and hence ICP) than going feet first. Unfortunately few ambulances are >>configured for taking a patient feet first. > >Simon is correct that on transition from a stationary position to forward >motion there is inclination of the nose of a helicopter for a few moments ( >5 to 10 seconds) before leveling out, although there is always a small >(less than 10 degree) residual inclination. > >Changing the location of the head of the casualty would also mean the need >to move the attendant so that they can attend to and continue to assess the >airway / communicate with the patient. The shift in weight in the HEMS >Dauphin would alter the centre of gravity of the aircraft and create >aviation problems. > >In a Twin Squirrel (Kent / Lancashire / HEMS stand-in aircraft) the head is >at the rear, again so that the head can be attended to. > >I worry about significant issues such as adequate oxygenation and cerebral >perfusion pressure in the critical heads, rather than a degree of "head >down" for for the relatively short flight times. This is where the >secondary injury can be minimised. Only in an ITU setting where inclination >is maintained for long periods might there be a significant difference in >ICP. > >In an ambulance that goes from stationary point to stationary point the >acceleration and deceleration forces must be equal - Isaac Newton ;-) > >Let's try keep things in perspective and be practical. > >DPW >Yorkshire > %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%