The chance of a quick recovery from an almost fatal injury largely depended on the original trauma and the patient's fitness level, a medical expert said yesterday.Professor Wilf Yeo, of the University of Wollongong's Graduate School of Medicine, said a person who had ingested poison such as drugs usually recovered more quickly than one who had suffered physical trauma, such as a head injury.The Mercury spoke with Prof Yeo in the wake of Shannan Taylor's amazing recovery, although he did not want to speak specifically on the boxer's case.He said that people were put on life support as a protective measure to allow the body to heal itself."It's a therapy, in a way," he said. "In terms of toxicology, when a patient comes into hospital having taken a poison of any description, often we use supportive measures, which can include putting them on life support if that drug is affecting the heart or the brain, or breathing."Then you wait for the body to get rid of that toxin."Patients were placed on life support for a number of reasons, including unconsciousness, difficulty breathing, a heart rate that was either too fast or too slow, or medical staff needing to control the situation."The easier thing is to put them in intensive care and put them on life support where you can artificially force the respiration, control the blood pressure, control the heart, and stop people from either having a fit or fighting you," he said."Then you gradually withdraw the extra supports in the hope that the patient makes a full recovery."Prof Yeo said the speed of recovery depended on the original injury.A seven-day turnaround in someone who had a drug overdose was not considered miraculous if the patient had been extremely fit. Age was another factor."The deconditioning time in a young person who is incredibly fit, who's just had a week out of action is not that much."The simplest thing is some sort of acute poisoning. If you can provide the support and the poison gets out of the system within a few days, there's a very good chance of complete recovery."