Original Article
Near-Infrared Spectroscopy in Adult Cardiac Surgery Patients: A Systematic Review and Meta-Analysis

https://doi.org/10.1053/j.jvca.2017.02.187Get rights and content

Objectives

To identify the normal baseline preoperative range of cerebral tissue oxygen saturation (SctO2) derived using near-infrared spectroscopy (NIRS) and the efficacy of perioperative interventions designed to modulate SctO2 in cardiac surgical patients.

Design

Systematic review and meta-analysis of relevant randomized controlled trials (RCTs) extracted from the Medline, Embase, and Cochrane Central Register of Controlled Trials databases.

Setting

Hospitals performing cardiac surgery.

Participants

The study comprised 953 participants from 11 RCTs.

Interventions

Interventions included the following: (1) SctO2 monitoring protocol compared with no monitoring; (2) use of cardiopulmonary bypass (CPB) compared with no CPB; (3) normothermic CPB compared with hypothermic CPB; (4) glyceryl trinitrate during surgery compared with placebo; (5) midazolam during induction of anesthesia compared with propofol; (6) sevoflurane anesthesia compared with total intravenous anesthesia; (7) sevoflurane anesthesia compared with propofol-based anesthesia; and (8) norepinephrine during CPB compared with phenylephrine.

Measurements and Main Results

Eleven RCTs with 953 participants measured baseline preoperative SctO2 using NIRS. The pooled mean baseline SctO2 was 66.4% (95% CI 65.0-67.7), generating a reference range of 51.0% to 81.8%. Four interventions (1, 3, 4, and 6 described in the Interventions section above) increased intraoperative SctO2 across the majority of reported time points. Postoperative follow-up of SctO2 occurred in only 1 study, and postoperative cognitive assessment correlating SctO2 with cognitive function was applied in only 4 studies using variable methodology.

Conclusions

The authors have established that reference values for baseline NIRS-derived SctO2 in cardiac surgery patients are varied and have identified interventions that modulate SctO2. This information opens the door to standardized research and interventional studies in this field.

Section snippets

Methods

A protocol for this review was registered prospectively and published as part of the PROSPERO International Prospective Register of Systematic Reviews (CRD42016038410).7

Medline, Embase, and the Cochrane Central Registry of Controlled Trials were searched through April 15, 2016 for randomized controlled trials (RCTs) that included the evaluation of baseline preoperative SctO2 with NIRS in adult cardiac surgery patients, using “brain,” “oxygenation,” and “cardiac surgery” as initial search terms (

Results

The search strategy identified 601 reports for review: 140 in Medline, 256 in Embase, and 205 in Cochrane Central Registry of Controlled Trials. Of these, 11 RCTs with 953 randomized participants were included in the review (Fig 1). Characteristics of the included studies are shown in Table 1.1, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 There was a wide variation in methodologic quality of the included studies, with only 1 RCT12 satisfying a low risk of bias in all domains. Five RCTs were deemed

Key Findings

The authors conducted a systematic review of all RCTs of interventions measuring and designed to modify NIRS-derived SctO2 during CPB in adult patients and identified 11 RCTs that reported relevant information. From these studies, the pooled mean baseline preoperative SctO2 of this clinically heterogenous cohort of cardiac surgical patients was found to be approximately 66%, with a wide reference range. Moreover, the following 4 interventions were observed to possibly improve intraoperative SctO

Conclusions

This systematic review showed that the normal baseline SctO2 of cardiac surgery patients from 11 identified RCTs was approximately 66%, with a wide reference range. Moreover, this review suggested that intraoperative SctO2 may be modulated by particular interventions and confirmed there is a paucity of data on postoperative SctO2. Finally, the review demonstrated that there is very little or no RCT-derived information on any association between changes in intraoperative or postoperative SctO2

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  • Cited by (0)

    N.J. Glassford is supported by the Avant Doctors-in-Training Research Scholarship.

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