None listed
Conditions
Brief summary
The ENIGMA (Evaluation of Nitrous oxide In the Gas Mixture in Anaesthesia) Trial was a large (n = 2,050) pragmatic multicentre randomised trial in patients undergoing major surgery. The incidence of clinically significant postoperative pulmonary complications (PPCs) measured by routine chest radiography and postoperative full blood and microbiology testing, as well a septic complications, were found to be increased with N2O. The larger ENIGMA 2 Trial (n = 7,000) did not confirm the findings of ENIGMA that N2O increased rates of wound infection or sepsis. Unfortunately, ENIGMA 2 did not prospectively collect data on pulmonary complications. Given the pragmatic nature of the protocol for measurement of PPC incidence used in ENIGMA, it was seen as feasible to replicate it post hoc in the ENIGMA 2 trial sample, using data collected as part of routine postoperative clinical management in these patients. This was done in the cohort of patients recruited to the ENIGMA 2 Trial within Australia, which consisted of over 2,500 patients or approximately 35% of total trial recruitment.
Interventions
This study is investigating additional postoperative patient outcomes within 30 days of index suergy in pre-existing patients who were recruited to the ENIGMA 2 Trial (which was conducted between May 30, 2008 and Sept 28, 2013), which did not collect pulmonary complications data at the time of the trial. Data collection for the study involves retrospective inspection of individual patient hospital medical records from the index hospital admission and surgery, to collect the required data on post
This study is investigating additional postoperative patient outcomes within 30 days of index suergy in pre-existing patients who were recruited to the ENIGMA 2 Trial (which was conducted between May 30, 2008 and Sept 28, 2013), which did not collect pulmonary complications data at the time of the trial. Data collection for the study involves retrospective inspection of individual patient hospital medical records from the index hospital admission and surgery, to collect the required data on postoperative pulmonary complications following the index surgery. The trial intervention group received 70% nitrous oxide in oxygen inspired in the breathing circuit as part of inhalational general anaesthesia, delivered from post-induction of anaesthesia until end of surgery. The N2O concentration could be adjusted if the FIO2 is required to be increased due to arterial oxygen saturation measurements on the judgement of the attending anaesthetist.
Sponsors
Austin Health
Eligibility
Sex/Gender
All
Age
45 Years to No maximum
Healthy volunteers
No
Inclusion criteria
Participants randomised to the ENIGMA 2 Trial within Australia, according to the ENIGMA 2 inclusion criteria: Adult males and females age >/= 45 years, undergoing noncardiac surgery and general anaesthesia expected to exceed two hours. At increased risk of cardiac events, defined as any of history of coronary artery disease as defined by a history of any one of the following: i. angina ii. MI iii. segmental wall motion abnormality on echocardiography or a fixed defect on radionuclide imaging iv. a positive exercise stress test for cardiac ischaemia v. a positive radionuclide exercise, echocardiographic exercise, or pharmacological cardiovascular stress test for cardiac ischaemia vi. coronary revascularization (CABG or PTCA) vii. angiographic evidence of atherosclerotic stenosis > 50% of the diameter of any coronary artery viii. ECG with pathological Q waves in two contiguous leads heart failure cerebrovascular disease thought due to atherothrombotic disease aortic or peripheral vascular disease or three or more of the following risk factors: age >/=70 years any history of congestive heart failure diabetes and currently on an oral hypoglycaemic agent or insulin therapy current treatment for hypertension preoperative serum creatinine >175 micro mol/L (> 2.0 mg/dl) current or previous high cholesterol >6.2 mmol/L (> 240 mg/dl) history of a transient ischemic attack (TIA) (i.e. a transient focal neurological deficit that lasted less than 24 hours and thought to be vascular in origin) emergency/urgent surgery (i.e. surgery which must be undertaken within 24 hours of acute presentation to hospital) high-risk type of surgery (i.e. intrathoracic or intraperitoneal)
Exclusion criteria
having cardiac surgery marked impairment of gas-exchange expected to require Fi02> 0.5 intraoperatively specific circumstances where N2O is contraindicated (eg. volvulus, pulmonary hypertension, raised intracranial pressure) or the anaesthetist plans to use supplemental oxygen (eg. colorectal surgery) N2O unavailable for use.
Outcome results
None listed