The following is a summary of “Blood Pressure and Oxygen Targets on Kidney Injury After Cardiac Arrest,” published in the December 2023 issue of Nephrology by Rasmussen et al.
Researchers started a retrospective study to investigate whether specific post-resuscitation blood pressure and oxygenation targets in out-of-hospital cardiac arrest patients influence the development of acute kidney injury (AKI).
They conducted a sub-study within a randomized 2-by-2 factorial trial, where 789 comatose adults with out-of-hospital cardiac arrest and sustained return of spontaneous circulation were randomly assigned to achieve a target mean arterial blood pressure of either 63 or 77 mm Hg. Simultaneously, patients were randomly assigned to a restrictive oxygen target (Pao2 of 9 to 10 kPa) or a liberal oxygenation target (Pao2 of 13 to 14 kPa). Low post-cardiac arrest blood pressure and high oxygen boosted mild AKI risk in survivors but not severe or long-term kidney issues (based on a 759-patient, 48-hour+ survival study with KDIGO AKI classification).
The results showed that, at admission, the main population characteristics included an age of 64 years (54–73), 80% male, 90% with shockable rhythm, and a time to return of spontaneous circulation at 18 minutes (12–26). Those assigned to low blood pressure and liberal oxygen target exhibited a higher risk of AKI compared to those with high blood pressure and liberal oxygen target (84/193 [44%] vs. 56/187 [30%]; aOR, 1.87 [95% CI, 1.21–2.89]). Multinomial logistic regression showed that elevated AKI risk was explicitly associated with mild-stage AKI (KDIGO stage 1), with no difference in other risk groups. Despite higher in-hospital creatinine with low BP + high O2, AKI resolved by follow-up (6 & 12 months).
They concluded that low BP plus high oxygen post-cardiac arrest led to more mild AKI but not severe or long-term kidney issues.
Source: ahajournals.org/doi/10.1161/CIRCULATIONAHA.123.066012