Table 3.
Summary of outcomes reported by each study
| Author | Monitor | Effect on opioid consumption during anesthesia | Absolute difference in opioid consumption (converted to morphine equivalents) | Hemodynamic variables | Efficiency variables (i.e. time to extubation) | Postoperative pain and opioid consumption | Other |
|---|---|---|---|---|---|---|---|
| Won [21] | SPI | 30% Reduction in oxycodone consumption in the SPI group (p = 0.012) | 2.8 mg | No significant differences | Extubation time 3.4 min shorter with SPI (p = 0.03) | No significant differences | |
| Bergmann [17] | SPI | 25% Reduction in remifentanil consumption in SPI group (p < 0.05) | 0.12 mg kg−1 h−1 | No differences in mean HD variables (apart from intubation: Δ MAP 9 mmHg, p < 0.005) | Recovery times were reduced by 3–4 min in the SPI group (p < 0.05) | No significant differences | |
| Chen [18] | SPI | 23% Reduction in remifentanil consumption in the SPI group (p < 0.05) | 0.3 mg kg−1 h−1 |
No significant difference in mean values Number of episodes with hypertension, hypotension or bradycardia significantly reduced (p < 0.01) |
No significant differences | No significant differences | |
| Colombo [19] | SPI | No significant differences | NA | There was less sympathetic modulation as measured by heart rate variability indices in the SPI group (p < 0.01) | No significant differences | No significant differences | |
| Gruenewald [20] | SPI | No significant differences | NA | No differences in mean values or number of episodes | No significant differences | No significant differences | |
| Jain [16] | SPI | 12% Increase in fentanyl consumption in the SPI group (p = 0.017) | 0.024 mg kg−1 h−1 | No significant differences | Duration of surgery was 9.8 min reduced in SPI group (p = 0.03) | Fentanyl consumption was 7 μg less in SPI group (p = 0.01) and VAS was 0.6 points lower in SPI group (p = 0.04) | |
| Dundar [22] | ANI | 30% Reduction in remifentanil consumption in the ANI group (p = 0.027) | 33.5 mg | No significant differences | No significant differences | No significant differences | |
| Upton [24] | ANI | No significant differences | No significant differences | No significant differences (only total surgery time reported) | No significant differences | Pain scores in the first 90 min of PACU stay were on average 1.3 units lower pain scores in the ANI group (p = 0.01) | |
| Szental [23] | ANI | No significant differences | No significant differences | No significant differences | No significant differences | No significant differences | |
| Meijer [15] | NOL | 28% Reduction in remifentanil consumption in the NOL group (p < 0.001) | 0.18 mg kg−1 h−1 | No significant differences | Reversal to extubation time was 2 min shorter in NOL group (p = 0.03) | No significant differences | |
| Martinez [25] | CARDEAN |
No significant difference in alfentanil consumption (dose corrected for duration) Increased number of patients in the CARDEAN group received alfentanil (83% vs. 61%; p = 0.003) |
NA | No significant differences | No significant differences | No significant differences | There was a 50% reduction in unwanted movements with CARDEAN monitoring at BIS values < 60 (p = 0.001) |
| Sabourdin [26] | Pupillometry | 48% Reduction in remifentanil consumption in pupillometry group (p < 0.001) | 0.42 mg kg−1 h−1 | More patients required nicardipine in pupillometry group (42.3% vs. 0%; p < 0.001) | No significant differences |
Reduced morphine consumption 0–12 h (mean difference 0.1 mg kg−1) No difference in pain scores |
Significant correlation between remifentanil consumption and postoperative morphine requirements |
Intraoperative opioid consumption was converted to morphine equivalents in mg kg−1 h−1 if possible
ANI analgesia nociception index, BIS bispectral index, CARDEAN cardiovascular depth of anesthesia index, ENT ear-nose-and-throat, HD hemodynamic, NA not available, NOL nociception level, SE state entropy, SPI surgical plethysmographic index