Coroners Act 1995
Coroners Rules 2006
Rule 11

I, Michael Brett, Coroner, having investigated the death of

Jonathan Paul DENT



(a) Jonathan Paul Dent (Mr Dent) died on or about 19 April 2011 in the Dial Ranges at North Motton;

(b) Mr Dent was born on 24 September 1981 in Victoria.  He was aged 30 years at the time of his death;

(c) Mr Dent died from natural causes after becoming lost and disorientated whilst bushwalking.  Although the cause of death cannot be determined with certainty, it is probable that he suffered a condition of exercise related hyponatremia during the bushwalk, which has resulted in death;

(d) No other person contributed to the cause of Mr Dent’s death.


Circumstances Surrounding the Death: 

Mr Dent set out for a bushwalk alone at approximately 9:30am on 19 April 2011 from Wings Wildlife Park at Gunns Plains.  His intention was to follow a walking track to Foggs Flat at Gunns Plains.  This was an estimated walk of approximately four hours.  He had arranged to meet his wife at the Foggs Flat footbridge at 1:30pm.

Mr Dent was in apparent good health, and well equipped for the walk.  He was wearing appropriate clothing and was carrying a day pack which contained among other items, a compass, maps, food and a first aid kit.  He was carrying a one litre bottle of water.  He believed that that would be sufficient for the planned walk, and was aware that he could obtain water from streams if that became necessary.  He was also carrying a fully charged mobile telephone.

At about 1:30pm, Mr Dent’s wife received a telephone call from him, indicating that he was lost, but would still attempt to make his way to the planned meeting spot.  Throughout the course of the afternoon, Mrs Dent received a number of further calls from him, each indicating that he was still lost.  At 4:00pm she received a telephone call from Mr Dent indicating that he was tired and dehydrated.  He was breathing heavily and coughing, and indicated to her that he was lying down.  She received a further call at 4:30pm in which she described him as sounding flustered and out of character.  He said to her “Where are you.  I thought you were coming to get me.  I need you to help me”.  The last telephone call she received was at 5:00pm.  At that point, he indicated that he thought he was getting close to the meeting point.

Mrs Dent sought assistance from nearby residents. At 8:25pm she reported Mr Dent missing to Ulverstone Police.

A search was activated shortly thereafter.  Some preliminary measures were taken, including activating local SES search teams, clearing a track for the entry of vehicles the following morning and having a police car activate its siren at the destination point on a regular basis to provide some orientation to Mr Dent if he was close by.  However, a full search could not be commenced at that time due to safety concerns, given that it was dark.

Walking search teams searched for the whole of the next day and the following day.  At 1:10pm Mr Dent was located by one of the search teams on a track known as the Tramway Track, north of Foggs Flats, North Motton.  Mr Dent was deceased.  He was laying face down with his backpack and gaitors removed.  The area around his feet was disturbed by what appeared to be scuff marks, and a fallen tree was lying in the vicinity of his body.

The post mortem report found no signs of significant external trauma, nor was it able to determine a cause of death.  There were some signs of dehydration.  The Pathologist has postulated that Mr Dent may have suffered an epileptic episode as a result of dehydration.  This was said to be consistent with the scuff marks around his feet.

Mr Dent was in apparent good health.  Family members confirm that there was no history of illness or any significant medical condition.  He had experience as a bushwalker, and was experienced in map reading and navigation.  He had undertaken some short walks since arriving in Tasmania 3 months earlier. He was employed as a minister for religion with the Salvation Army and was committed and passionate in his work. He had a close and loving relationship with his wife.

Given the findings of the post mortem and the lack of any other clear evidence pointing to a cause of death, I arranged for the evidence in this matter to be reviewed by a medical expert, Clinical Professor Anthony Bell.  I have been provided with Professor Bell’s report.

Professor Bell’s opinion is that the evidence leads to the conclusion that death has resulted from a condition described as exercise-associated hyponatremia (EAH). The condition consists of a dilution of serum sodium which occurs during or up to 24 hours after prolonged (greater than 4 hours) activity.  Professor Bell’s opinion is based on the following:

(a) That Mr Dent’s fitness and conditioning would have been relatively low, particularly having regard to the nature of the bushwalk that he was undertaking.  Although Mrs Dent’s evidence is to the effect that Mr Dent had performed a number of walks and that they walked regularly for exercise, she also concedes that he was “not as fit as he would have liked to be”.  Further, it is likely that the walk became far more strenuous once Mr Dent became lost and disoriented. He probably wandered over a much greater distance than would have been the case had he not become lost and simply walked a direct line along his original route.

(b) There are numerous other indications that Mr Dent was suffering from the said condition.  His conversations with Mrs Dent, particularly the last conversation, and his unusual presentation to her is consistent with the onset of the condition.  Professor Bell has also noted that the autopsy showed a swollen brain with signs of herniation, which is again consistent with water excess, rather than dehydration.  Professor Bell is clear that the deceased was not dehydrated.

Professor Bell provides some further comments relating to the condition in the context of this case as follows:

The clinical manifestations of acute hyponatremia due to exercise-associated hyponatremia (EAH) vary with severity and are at least in part related to cerebral oedema resulting from osmotic water movement from the extracellular fluid into the brain.  Nausea and malaise, which are the earliest findings, may be seen when the serum sodium concentration falls.  Headache, lethargy, obtundation and eventually seizures, coma, and respiratory arrest can occur.  Some athletes complain only of feeling ill, lie quietly, often in a foetal position, and want to avoid light and contact with other people.  They appear lucid, but cannot concentrate and may be a little confused.  The telephone conversations between Mr Dent and Mrs Dent suggest that this process is happening, especially the “hanging up” and the non-answering of the telephone. Once the process has started the ability to concentrate and solve the “I’m lost” problem is diminished significantly, as appears to be to have happened in this case.

Severe manifestations of EAH include seizures, confusion, coma, and death.  Cerebral oedema can often be demonstrated on CT scan or at post-mortem examination.  Although the mechanism is uncertain, non-cardiogenic pulmonary oedema has also been described in these patients and causes shortness of breath, but the autopsy did not reveal pulmonary oedema.  The clinical manifestations of seizure were suggested by the disturbances at the scene as described in the report and the opinion of Dr Brain.  The autopsy showed a swollen brain with signs of herniation the cause of death in this syndrome.  As the weight of the brain decreases with dehydration and increases with water excess (hyponatremia) a heavier than usual brain weight is indicative that the brain contained extra fluid. Thus the deceased was not dehydrated.  The evidence to suggest dehydration, an empty bladder and an empty water bottle are soft evidence. In EAH the urine volume is minimal, and the sufferer is drinking water so the empty bladder and empty water bottle may represent EAH.

I accept Professor Bell’s opinion.  I find that the most likely cause of death was exercise related hyponatremia, which itself resulted from excessive consumption of water during the course of the prolonged exertion of the bushwalk.  It is impossible to determine whether the condition resulted from the circumstances after Mr Dent had become lost and disoriented, or alternatively was in fact the reason why he became lost and disoriented. 

Comments & Recommendations:

I have decided not to hold an inquest into Mr Dent’s death.  It seems to me that the investigation has elicited all possible information surrounding this death and that nothing more could be gained by the holding of an inquest.

It seems to me that this case highlights two specific concerns:

(a) Professor Bell is highly critical of the general public perception, particularly prevalent among those pursuing athletic activities, and based on common recommendations, that one should drink “as much as possible” and avoid becoming dehydrated, during prolonged strenuous exercise.  He notes that excessive consumption of fluid is poorly understood in the community.  He notes further that “Some 10% of people running the Boston Marathon suffered from EAH.  In the Christchurch Marathon where drink stations are 5 kilometres apart (Boston 1.6 kilometres apart) the incidence is significantly lower”.

Professor Bell’s comments, and the circumstances of this case, suggest that there is a need for greater education in the community in relation to the danger associated with excessive consumption of fluid during exercise.  I recommend that health authorities consider and address the question of whether public health education in this area is adequate and/or accurate, having regard to current scientific knowledge.

(b) The danger involved in bushwalking alone.  Had Mr Dent been in company, whilst it cannot be said that he would not have suffered the condition that led to his death, I suspect that he would have been in a substantially better condition to cope with the disorientation and fear that arose from becoming lost.  It is possible, although far from certain, that had he been in company, and as a consequence, had assistance in finding his way to his destination, that he may have survived. At the very least, his chances of survival would have been significantly enhanced.

Having said this, it is well known in the community that bushwalking is an inherently dangerous activity.  The dangers, and the need for appropriate preparation are well publicised by the appropriate authorities.  Apart from my comments above, I do not see any need to make any further recommendation as a result of this case.

I take this opportunity to convey my sincere condolences to Mr Dent’s family and loved ones.

The matter is now concluded.

DATED: 31 August 2012 at Devonport in the State of Tasmania


Michael Brett