Mr Saint went into cardiac arrest during routine knee replacement surgery on June 23 last year after a breathing tube was wrongly inserted into his oesophagus.The 71-year-old received no lung ventilation for 21 minutes during a period in which three senior anaesthetists failed to spot the error. He suffered irreversible brain damage and died five days later in the hospitals critical care unit. During the inquest, the theatre department at Hinchingbrooke was described as hierarchical and questions were raised about whether non-medical, and less senior staff, were listened to or had a voice. Hinchingbrooke commissioned an independent report into the incident and an action plan was devised, which included human factors, difficult airway and skills training. Dr Kanchan Rege, medical director at North West Anglia NHS Foundation Trust, which oversees the running of Hinchingbrooke Hospital, said: Following Mr Saints death, a report from an independent anaesthetist was obtained and formed the basis of an extensive action plan, on which good progress has already been made. A general training programme across our medical workforce has addressed some of the staffing issues raised in the report and some individual retraining has also taken place. The anaesthetist in charge that day was Dr Ingo Hille who admitted he made a crucial error, in his misplacement of the tube, but the inquest heard this was compounded by a failure on the part of fellow anaesthetists, Dr Abdu Ayman and Dr Vaithseewaran Silva, to identify the error. Mr Saint underwent general anaesthetic at about 3pm and orthopaedic surgeon Mairwann El-Kaubaisy began the surgery, but at 3.40pm the monitoring equipment flagged up problems. The surgery was halted and Mr Saints breathing mask was removed, at which point he regurgitated a large amount of brown liquid. Dr Hille fitted a new mask and when, at 4pm, Mr Saint was still in some difficulty, Dr Hille wrongly inserted the breathing tube. Mr Saint went into cardiac arrest at 4.05pm. The inquest was told that during this time, a monitor, recording the CO2 levels, would have shown a flat white line and a zero reading, indicating Mr Saint had no lung ventilation. Operating department practitioner, Mick Collins entered the theatre after Mr Saint was in cardiac arrest and pointed out three times that the tube was not in the right place, but his view was rejected. Mr Collins was described as a highly respected and valued member of the team, but the three anaesthetists were fixated on resolving side issues, said coroner Sean Horstead. Mr Horstead added: Dr Hilles error was, in effect, reinforced by Dr Abdu and Dr Silva and provided a confirmatory bias that the tube had been placed correctly. At 4.25pm, Dr Muhammad Asif confirmed the misplaced tube and relocated it. Mr Horstead said he would be writing to the head of anaesthesia at Hinchingbrooke Hospital and the Royal College of Anaesthetists to raise concerns about aspects of the evidence he had heard in relation to the misinterpretation of the monitoring equipment readings.Inquest verdictCoroner Sean Horstead said Mr Saints death had been caused by human factors and the hierarchical culture in the theatre had played a significant role in the error not being spotted sooner. He found no fault with the pre-operative procedure, carried out by Alison Glass-Parker and Dr Hille. There was no issue with Dr Hilles choice of anaesthetic mask and no fault with the monitoring equipment or the layout of the readings. He said misplacing breathing tubes was an occupational hazard for anaesthetists, but in Mr Horsteads view, there was a secondary element and that was checking it had been inserted correctly. He said the gold standard for this was the monitor recording CO2 readings and a fleeting glance was not enough and 15-20 seconds was more appropriate. He said: A failure to engage in such a check was a serious and fundamental error on the part of all three anaesthetists. The medical cause of death was recorded as the result of oesophageal tube placement, which caused a cardiac arrest and led to brain damage after lack of oxygen supply for 21 minutes.