Obituary| Volume 20, ISSUE 3, P206-207, July 2011

M.E. Tunstall (1928–2011)

      Mike Tunstall was easily the most important UK contributor to obstetric anaesthesia in the 20th century. His unassuming modesty gave no glimmer of this. He was a true original thinker and made a remarkable number of ground-breaking and life-saving advances in obstetric anaesthesia and neonatal resuscitation. The clarity of his thought is mirrored by clarity of expression in all his writing.
      Mike was instrumental in the development of neonatal tracheal tubes both for resuscitation and for anaesthesia. He also pioneered the use of neonatal mechanical ventilation. For his work with neonates he earned the respect of his paediatric colleagues; for an anaesthetist to be recognised by paediatricians is surely an achievement.
      Probably his best known advance was the invention of Entonox. When I first encountered women in labour, in the 1950s, they were given nitrous oxide mixed with air for pain relief. When the apparatus was working correctly (which it often was not), it delivered 10% oxygen, hardly suitable during labour. The British Oxygen Company (BOC) affirmed that nitrous oxide and oxygen, stored as a liquid and a gas, respectively, could not be combined in a single cylinder. Tunstall, evidently a better physicist than the scientists at BOC, and aware of the Poynting effect, was not to be put off. He set about showing that nitrous oxide and oxygen could be mixed in a single cylinder so as to form a stable 50:50 gas mixture, and so created Entonox, a far safer and more convenient way to give nitrous oxide than as gas and air. BOC, although more obstructive than helpful in its development, were not slow to patent Entonox, granting Tunstall no mention. Obstetric anaesthetists may look upon Entonox primarily as a method of labour analgesia, but it has, as we know, countless other applications, including providing safe analgesia while freeing trapped victims of traffic and other accidents, the Moorgate tube disaster, 7/7, etc. People suffering acute pain wherever Entonox is available have reason to be grateful to Mike Tunstall.
      To tackle the problem of awareness under light anaesthesia and muscle relaxation, Tunstall hit upon the brilliant solution, the isolated forearm technique. I remember him saying it was so simple he felt sure someone else would publish it first. By this means it became possible to identify and eliminate techniques that might lead not only to awareness but also to a state he was able to identify as amnesic wakefulness, which, although forgotten, could be traumatic.
      It is hard now to imagine life without a failed-intubation drill, but before Tunstall brought sanity to the situation, failed intubation was the cause of a series of maternal deaths in the Sixties and Seventies. Mike Tunstall said, in essence, “Don’t panic: plan!” and in 1971 developed the first failed-intubation drill, but I could not discover a description in print until an OAA meeting in 1976. Despite this delay, he was well in advance of his time and his development has saved countless lives.
      Mike Tunstall was born in India, but at the age of eight he was brought by his parents to go to prep school in Sheffield. There he stood on the steps of the school and waved good-bye to his parents for eight years. In those days there was no jetting about in the holidays, and World War 2 put a stop to inessential global travel. Sheffield never lost for him this tragic association. He was awarded a Foundation Scholarship to Monmouth School from where he went to the Chelsea Polytechnic and thence to University College Hospital Medical School. He qualified in 1952. After house jobs, National Service and some flirting with general practice, thankfully for the sake of obstetric anaesthesia he undertook prestigious anaesthetic training at Portsmouth, the Middlesex and Oxford. In 1962 he went to Aberdeen, where he stayed ever since. Although officially retired in 1992, and despite doing battle with leukaemia and head and neck cancer, he continued determinedly with his research into inhalational analgesia for several more years.
      His 96 publications span from 1959 to 2005. Amidst many honours and eponymous lectures, he was awarded the Gold Medal of the Obstetric Anaesthetists’ Association in 1990. The University of Aberdeen awarded him a DSc in 2006, the highest academic accolade that Universities bestow.
      He leaves his wife Anne of 57 years, their three children and six grandchildren.
      Obstetric anaesthetists have reason to be eternally grateful for his incredibly useful and productive life.