A Randomized Trial of Intravenous Amino Acids for Kidney Protection.

BACKGROUND: Acute kidney injury (AKI) is a serious and common complication of cardiac surgery, for which reduced kidney perfusion is a key contributing factor. Intravenous amino acids increase kidney perfusion and recruit renal functional reserve. However, the efficacy of amino acids in reducing the occurrence of AKI after cardiac surgery is uncertain. METHODS: In a multinational, double-blind trial, we randomly assigned adult patients who were scheduled to undergo cardiac surgery with cardiopulmonary bypass to receive an intravenous infusion of either a balanced mixture of amino acids, at a dose of 2 g per kilogram of ideal body weight per day, or placebo (Ringer's solution) for up to 3 days. The primary outcome was the occurrence of AKI, defined according to the Kidney Disease: Improving Global Outcomes creatinine criteria. Secondary outcomes included the severity of AKI, the use and duration of kidney-replacement therapy, and all-cause 30-day mortality. RESULTS: We recruited 3511 patients at 22 centers in three countries and assigned 1759 patients to the amino acid group and 1752 to the placebo group. AKI occurred in 474 patients (26.9%) in the amino acid group and in 555 (31.7%) in the placebo group (relative risk, 0.85; 95% confidence interval [CI], 0.77 to 0.94; P = 0.002). Stage 3 AKI occurred in 29 patients (1.6%) and 52 patients (3.0%), respectively (relative risk, 0.56; 95% CI, 0.35 to 0.87). Kidney-replacement therapy was used in 24 patients (1.4%) in the amino acid group and in 33 patients (1.9%) in the placebo group. There were no substantial differences between the two groups in other secondary outcomes or in adverse events. CONCLUSIONS: Among adult patients undergoing cardiac surgery, infusion of amino acids reduced the occurrence of AKI. (Funded by the Italian Ministry of Health; PROTECTION ClinicalTrials.gov number, NCT03709264.).

Ketamine versus etomidate as an induction agent for tracheal intubation in critically ill adults: a Bayesian meta-analysis.

BACKGROUND: Tracheal intubation is a high-risk intervention commonly performed in critically ill patients. Due to its favorable cardiovascular profile, ketamine is considered less likely to compromise clinical outcomes. This meta-analysis aimed to assess whether ketamine, compared with other agents, reduces mortality in critically ill patients undergoing intubation. METHODS: We searched MEDLINE, Embase, and the Cochrane Library from inception until April 27, 2023, for randomized controlled trials and matched observational studies comparing ketamine with any control in critically ill patients as an induction agent. The primary outcome was mortality at the longest follow-up available, and the secondary outcomes included Sequential Organ Failure Assessment score, ventilator-free days at day 28, vasopressor-free days at day 28, post-induction mean arterial pressure, and successful intubation on the first attempt. For the primary outcome, we used a Bayesian random-effects meta-analysis on the risk ratio (RR) scale with a weakly informative neutral prior corresponding to a mean estimate of no difference with 95% probability; the estimated effect size will fall between a relative risk of 0.25 and 4. The RR and 95% credible interval (CrI) were used to estimate the probability of mortality reduction (RR < 1). The secondary outcomes were assessed with a frequentist random-effects model. We registered this study in Open Science Framework ( https://osf.io/2vf79/ ). RESULTS: We included seven randomized trials and one propensity-matched study totaling 2978 patients. Etomidate was the comparator in all the identified studies. The probability that ketamine reduced mortality was 83.2% (376/1475 [25%] vs. 411/1503 [27%]; RR, 0.93; 95% CrI, 0.79-1.08), which was confirmed by a subgroup analysis excluding studies with a high risk of bias. No significant difference was observed in any secondary outcomes. CONCLUSIONS: All of the included studies evaluated ketamine versus etomidate among critically ill adults requiring tracheal intubation. This meta-analysis showed a moderate probability that induction with ketamine is associated with a reduced risk of mortality.

Renin as a Prognostic Marker in Intensive Care and Perioperative Settings: A Scoping Review.

Serum renin increases in response to sympathetic nerve activation and hypotension. Recent studies have reported the association of serum renin levels with adverse clinical outcomes in acute care settings. This scoping review aimed to systematically review the available literature on renin as a prognostic marker in intensive care and perioperative patients. We searched for studies published since inception until March 31, 2023, which assessed the association between serum renin levels and clinical outcomes or the effect of synthetic angiotensin II administration on serum renin levels in critically ill and perioperative patients in PubMed, Embase, and the Cochrane Library. The primary outcome was mortality at the longest follow-up; the secondary outcomes were adverse renal outcomes (ie, acute kidney injury, the need for renal replacement therapy, and major adverse kidney events), hemodynamic instability, outcomes to angiotensin II administration, and prognostic performance for mortality when compared with lactate. Among the 2081 studies identified, we included 16 studies with 1573 patients (7 studies on shock, 5 on nonspecific critical illness, 2 on cardiac surgery, 1 on noncardiac surgery, and 1 on coronavirus disease 2019). A significant association between serum renin levels and poor outcomes was identified in 14 studies, with 10 studies demonstrating an association with mortality. One post hoc analysis found that angiotensin II administration reduced mortality in patients with markedly elevated renin values. Two studies showed that renin was superior to lactate as a prognostic marker of mortality. Our scoping review showed that elevated serum renin levels may be associated with clinically relevant outcomes among various perioperative and intensive care populations. Increased serum renin levels may identify patients in which synthetic angiotensin II administration improves clinical outcomes and may outperform serum lactate in predicting mortality.

Haptoglobin Administration for Intravascular Hemolysis: A Systematic Review.

Introduction Exogenous haptoglobin administration may enhance plasma-free hemoglobin (pfHb) clearance during hemolysis, and reduce its end-organ damage: we sought to systematically review and summarize available evidence on the use of haptoglobin as a treatment for hemolysis of any cause. Methods We included studies describing haptoglobin administration as treatment or prevention of hemolysis-related complications. Only studies with a control group reporting at least one of the outcomes of interest were included in the quantitative synthesis. Primary outcome was the change in pfHb concentration 1 hour after haptoglobin infusion. Results Among 573 articles, 13 studies were included in the review (677 patients, 52.8% received haptoglobin). Median initial haptoglobin intravenous bolus was 4000 (2000, 4000) IU. Haptoglobin was associated with lower pfHb 1 hour (SMD -11.28; 95% CI -15.80 to -6.75; p<0.001) and 24 hours (SMD -2.65; 95% CI -4.73 to -0.57; p=0.001) after infusion. There was no difference in all-cause mortality between haptoglobin-treated patients and control group (OR 1.41; 95% CI 0.49 to 4.95; p=0.520). Haptoglobin was associated with a lower incidence of acute kidney injury (OR 0.64; 95% CI 0.44-0.93; p=0.020). No adverse events or side effects associated with haptoglobin use were reported. Conclusions Haptoglobin administration has been used in patients with hemolysis from any cause to treat or prevent hemolysis-associated adverse events. Haptoglobin may reduce levels of pfHb and preserve kidney function without increase in adverse events.

Effect of Urine Output on the Predictive Precision of NephroCheck in On-Pump Cardiac Surgery With Crystalloid Cardioplegia: Insights from the PrevAKI Study.

OBJECTIVES: Previous studies in other settings suggested that urine output (UO) might affect NephroCheck predictive value. We investigated the correlation between NephroCheck and UO in cardiac surgery patients. DESIGN: Post hoc analysis of a multicenter study. SETTING: University hospital. PARTICIPANTS: Patients who underwent cardiac surgery using cardiopulmonary bypass (CPB) and crystalloid cardioplegia. MEASUREMENTS AND MAIN RESULTS: All patients underwent NephroCheck testing 4 hours after CPB discontinuation. The primary outcome was the correlation between UO, NephroCheck results, and acute kidney injury (AKI, defined according to Kidney Disease: Improving Global Outcomes). Of 354 patients, 337 were included. Median NephroCheck values were 0.06 (ng/mL)2/1,000) for the overall population and 0.15 (ng/mL)2/1,000) for patients with moderate to severe AKI. NephroCheck showed a significant inverse correlation with UO (ρ = -0.17; p = 0.002) at the time of measurement. The area under the receiver characteristic curve (AUROC) for NephroCheck was 0.60 (95% confidence interval [CI], 0.54-0.65), whereas for serum creatinine was 0.82 (95% CI, 0.78-0.86; p < 0.001). When limiting the analysis to the prediction of moderate to severe AKI, NephroCheck had a AUROC of 0.82 (95% CI, 0.77 to 0.86; p<0.0001), while creatinine an AUROC of 0.83 (95% CI, 0.79-0.87; p = 0.001). CONCLUSIONS: NephroCheck measured 4 hours after the discontinuation from the CPB predicts moderate to severe AKI. However, a lower threshold may be necessary in patients undergoing cardiac surgery with CPB. Creatinine measured at the same time of the test remains a reliable marker of subsequent development of renal failure.

Meta-Analysis of Glucocorticoids for Covid-19 Patients Not Receiving Oxygen.

BACKGROUND: Glucocorticoids reduce mortality in hospitalized patients with severe and critical coronavirus disease 2019 (Covid-19), although a possible harm was documented in patients with Covid-19 not requiring oxygen. METHODS: We searched Embase, BioMed Central, medRxiv, bioRxiv, PubMed, and the Cochrane Central Register of Controlled Trials for any randomized trial or matched study ever performed on adult patients with Covid-19 not receiving oxygen therapy treated with intravenous or oral glucocorticoids versus any comparator (standard therapy or placebo); there were no restrictions on dose or time of administration. The primary end point was all-cause mortality at the longest available follow-up. RESULTS: Five randomized trials and one propensity-matched study involving 6634 hospitalized patients not on oxygen were finally included (3704 received glucocorticoids and 2930 received standard treatment). The overall mortality of patients treated with glucocorticoids was significantly higher than the mortality of patients in the control group (509 of 3704 [14%] in the glucocorticoid group vs. 294 of 2930 [10%] in the control group; odds ratio, 1.56 [95% confidence interval, 1.27 to 1.92], with three articles reporting mortality events and contributing to the combined odds ratio; P<0.001; number needed to harm=27). CONCLUSIONS: Glucocorticoid use likely increases mortality in hospitalized patients with Covid-19 not receiving oxygen, with a number needed to harm of 27. (PROSPERO number CRD42022342996.)