Cerebral Oximetry Monitoring to Maintain Normal Cerebral Oxygen Saturation during High-risk Cardiac Surgery

Abstract

Background Cerebral oxygen desaturation during cardiac surgery has been associated with adverse perioperative outcomes. Before a large multicenter randomized controlled trial (RCT) on the impact of preventing desaturations on perioperative outcomes, the authors undertook a randomized prospective, parallel-arm, multicenter feasibility RCT to determine whether an intervention algorithm could prevent desaturations. Methods Eight Canadian sites randomized 201 patients between April 2012 and October 2013. The primary outcome was the success rate of reversing cerebral desaturations below 10% relative to baseline in the intervention group. Anesthesiologists were blinded to the cerebral saturation values in the control group. Intensive care unit personnel were blinded to cerebral saturation values for both groups. Secondary outcomes included the area under the curve of cerebral desaturation load, enrolment rates, and a 30-day follow-up for adverse events. Results Cerebral desaturations occurred in 71 (70%) of the 102 intervention group patients and 56 (57%) of the 99 control group patients (P = 0.04). Reversal was successful in 69 (97%) of the intervention group patients. The mean cerebral desaturation load (SD) in the operating room was smaller for intervention group patients compared with control group patients (104 [217] %.min vs. 398 [869] %.min, mean difference, −294; 95% CI, −562 to −26; P = 0.03). This was also true in the intensive care unit (P = 0.02). There were no differences in adverse events between the groups. Conclusions Study sites were successful in reversal of desaturation, patient recruitment, randomization, and follow-up in cardiac surgery, supporting the feasibility of conducting a large multicenter RCT.

Diagnostic and therapeutic medical devices for safer blood management in cardiac surgery: systematic reviews, observational studies and randomised controlled trials

“…Random sequence generation was adequate in seven trials, 45,154,235,240,241,243,246 and unclear in two trials. 242,245 There was a high risk of bias for random sequence generation in one trial.…”

“…In seven trials NIRS values were measured in the control group, although this was hidden from the clinical personnel. 154,235,[241][242][243]245,246 No trial considered an alternative patient-specific goal-directed algorithm.…”

“…There was evidence of blinding of participants and clinical staff caring for participants postoperatively in four trials, 45,154,242,244 with unclear evidence in six trials. 235,240,241,243,245,246 Three trials reported the frequency of protocol compliance. 45,154,241 In seven trials non-compliance was not monitored or not specified.…”

“…In one trial 241 three different devices were used: INVOS, FORE-SIGHT (CAS Medical Systems Inc., USA) and EQUANOX Classic 7600 (Nonin Medical Inc., USA). In two trials the target NIRS value was > 75% of baseline.…”

“…154 In one trial the intervention threshold was specified as a 10% decrease in the regional cerebral oxygen saturation (rSO 2 ) value relative to baseline for a duration exceeding 15 seconds. 241 Seven trials used a version of the Murkin algorithm to optimise NIRS values. 154,235,240,242,243,245,246 Three studies used non-Murkin algorithms.…”