A coroner has highlighted the importance of using CPAP and oxygen monitoring immediately after surgery to correct severe obstructive sleep apnea, in the case of a man who died from complications of hypoxia.
The Tasmanian coroner investigated the death of a 50-year-old man who developed deadly multiple pulmonary thromboemboli in the weeks after surgery to remove obstructive tissues to widen his airway at Calvary St John’s Hospital in Hobart.
His investigation concluded this would likely not have occurred had the man had oxygen saturation monitoring in the post-operative period and used the CPAP device he had been used for two years and had brought to the hospital from home.
Neither of these interventions occurred, partly because the hospital did not have in place a post-operative care pathway for the uvulopalatopharyngoplasty (UPPP) procedure he underwent.
The man had a long history of OSA, along with allergic rhinitis and a deviated nasal septum, and was first recommended a mandibular advancement device in 2001.
In 2014 moved onto CPAP and also saw surgeon who recommended a two-step surgery consisting of septoplasty and a reduction of the inferior turbinates followed by UPPP. The man underwent the first surgery in 2015. On August 2016, he was admitted to Calvary for the UPPP.
After uneventful surgery he was moved to the ward where nurses worked off a post-operative care pathway for adult tonsillectomy, in the absence of a specific protocol for UPPP.
There was also post-operative instructions from the surgeon, but these did not include instructions to administer oxygen saturation monitoring or the CPAP which she had advised the patient to bring from home.
At 5 am the morning after the surgery a nurse noted that the man was snoring loudly, but at 5.30 am became quiet.
When she went to wake him at 6.15 am he was unresponsive, and it was subsequently discovered that he had oxygen saturation levels of 22% and a pulse of 85bpm and.
The patient was transferred to the Royal Hobart Hospital where he was stabilised, but almost three weeks later a CT scan found a saddle embolism with a near total occlusion of the right pulmonary artery. Despite treatment with continuous heparin, the man developed bilateral deep vein thrombosis and died on September 5 2016.
The coroner noted that the surgeon and anaesthetist had advised the patient that his CPAP machine should be used post operatively, but there was no written order to staff to ensure this.
The two nurses on the ward held a mistaken belief that CPAP was unsafe to use following UPPP, saying they thought it would harm the fragile tissues that had been subject to surgery.
“In my experience, in relation to airway operations, CPAP machines are not usually used because of the positive pressure that it creates on the airway, sutures and throat. If a patient has had surgery on the throat, I understand that the pressure on the airway may cause additional damage/bleeding and not assist healing,” one said.
The coroner also noted that a proper standard of post-operative care would include continuous oxygen saturation monitoring, and had it been in place, the life-threatening hypoxia could have been averted.
“In all likelihood, [the patient’s] death would have been prevented if both or either of these steps had been taken during his post-operative phase,” he said.
The coroner noted that Calvary Hospital had since introduced a specific post-operative clinical pathway for UCCC which includes the use of CPAP and continuous oxygen saturation monitoring. The hospital had also made 28 additional recommendations that if fully implemented would reduce the chances of a similar tragedy occurring.