Compare the effects of altitude/depth verses pressure.
At the surface atmospheric pressure is 1 atmosphere (1 bar) by definition.
Consider a descent under water. At 10m below sea level the pressure is 2 atmospheres & at 20m it is 3 atmospheres. This continues in a roughly linear fashion due to water being incompressible.
Now consider a climb in an aircraft. 1 millibar (a thousandth of an atmosphere) = 27 feet at sea level (air of course is compressible so the pressure change is not linear but can be considered so over small altitude changes). So at 1500' the pressure will have changed by 55 millibars, ie 0.055 atmospheres.
For the bends to have been a concern a diver would need to go down to 20m & for a serious case probably significantly more. So having already had a 2 atmosphere pressure change another 0.055 is insignificant, & indeed the kind of altitudes a SAR helicopter would normally transit at will have little additional effect. That said obviously the lower you can safely fly the better.
As an aside it is normally recommended that leisure divers allow 24 hours before flying. This is not because normal cabin altitudes are likely to be a problem but a cabin decompression at 39000' could cause real problems for a diver.