Michalopoulos 1998.
| Methods | Parallel‐group single‐blinded randomized controlled trial, conducted in Greece. Study dates not reported | |
| Participants | 144 elective coronary artery bypass patients younger than 70 years of age, with ejection fraction ≥ 35%, New York Heart Classification Class I to III, with normal preoperative respiratory function. Excluded were those with chronic renal failure, hepatic failure or cerebral dysfunction, and those who underwent redo CABG surgery | |
| Interventions | Low‐dose opioid, early extubation (4 to 7 hours) in 72 participants. Anaesthesia included fentanyl 15 to 20 μg/kg at induction and 5 μg/kg for maintenance, followed by ICU sedation and analgesia (morphine and propofol) for 2 hours. High‐dose opioid, usual care (extubation 8 to 14 hours) in 72 participants. Anaesthesia included fentanyl 50 μg/kg at induction and 10 to 15 μg/kg for maintenance, followed by ICU sedation and analgesia (morphine and midazolam) for 6 hours. Details of who decided when to extubate were not given. |
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| Outcomes | Risk of mortality in hospital Risk of myocardial infarction (new and persistent Q waves at ECG associated with an abrupt rise in CPK, CPK‐MB and troponin values) Risk of stroke Risk of sepsis Risk of major bleeding (blood loss > 500 mL during the first 6 postoperative hours, or blood loss necessitating transfusion of > 3 red cell units during the first 12 postoperative hours) Risk of acute renal failure Risk of tracheal reintubation Time to extubation Length of stay in the ICU Length of hospital stay |
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| Notes | No power calculation was done. No details were provided about funding source or any declarations of conflict of interest among study authors. | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | No details given |
| Allocation concealment (selection bias) | Unclear risk | No details given |
| Blinding (performance bias and detection bias) All outcomes | Low risk | "Operative and postoperative complications were assessed blinded to the randomization of the allocation" |
| Incomplete outcome data (attrition bias) All outcomes | Unclear risk | No details given |
| Selective reporting (reporting bias) | Low risk | All outcomes collected and reported |
| Other bias | Low risk | Participant characteristics between groups were similar for gender, smoking, age, preoperative LVEF (%) and NYHA classification |