Assessment of a goal-directed perfusion strategy through an oxygen delivery audit

Evidence supports the role of oxygen delivery (DO₂) in ameliorating acute kidney injury (AKI). While instrumentation for continuous DO₂ measurement exists, a simplified method has been reported for targeting a specific DO₂ index (DO₂i), commonly referred to as a goal-directed perfusion (GDP) strategy, by using a reference table and available data such as body surface area and continuous haematocrit values. This simplified approach can also be used for quality auditing via archived data.

This retrospective sequential audit was conducted to assess the impact of employing a GDP strategy within our institution by examining perfusion practices, DO₂ levels and renal outcomes before and after implementation. A total of 246 patients undergoing elective primary coronary revascularisation were included: 125 patients in the pre-change group and 121 patients in the post-change group. A DO₂i threshold above 280 mL/min/m² was targeted in the post-GDP group.

While both groups maintained a mean DO₂ above the threshold, the post-GDP group exhibited a higher average DO₂i (311 vs 291 mL/min/m²). The GDP strategy led to higher nadir DO₂i (255 vs 225, p < .001) and was coupled with a reduction in the time below the 280 mL/min/m² threshold (30 min vs 50 min, p < .001). The average cardiac index in the post-GDP group was higher (1.87 vs 1.65, p < .001) while also demonstrating a smaller creatinine rise of 6.8% compared to 13.5% in the control group (p = .035). There was no difference in AKI or mortality rates between the groups.

The implementation of the GDP strategy demonstrated an enhancement in oxygen delivery during cardiopulmonary bypass, primarily attributable to elevated pump flow rates. A statistically significant decrease in serum creatinine levels was observed. The published reference table emerged as a simple yet effective tool in optimising our GDP strategy.