As cold as it might sound, in air ambulance, you have to remember, you (the pilot), and your medcrew are already in good health. The aircraft is in good shape. The patient is already compromised. It is not worth it to take an unreasonable risk and endanger the lives of the ones who are healthy and possibly destroy the aircraft that could be used to transport many, many more patients in the future. In the long run, it's best for more people if you think of the patient in the back as a bag of hammers. You should not take unnecessary risks because you are worried that the patient might die, that's something that the pilot has to learn to desensitize himself/herself to. If it's unsafe to complete the mission as planned then change the plan, no ifs ands or buts about it.