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.).

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.

Shaping the Anesthetic Approach to TricValve Implantation: Insights From a Case Series.

OBJECTIVES: Caval valve implantation (CAVI) represents a minimally invasive strategy for managing severe tricuspid regurgitation in high-risk patients unsuitable for surgical or transcatheter tricuspid valve implantation. This case series aimed to assess the anesthesia management challenges and outcomes associated with this procedure, seeking to generate insights that can inform and refine anesthesia protocols. DESIGN: A case series. SETTING: At a cardiac catheterization laboratory of a teaching hospital. PARTICIPANTS: Eight patients undergoing CAVI with the Tricvalve system INTERVENTIONS: The anesthetic protocol included preprocedural planning, fast-track general anesthesia, and postprocedural debriefing. Intraoperative management involved anesthesia depth monitoring, real-time guidance via transesophageal echocardiography, and hemodynamic stability maintenance. Postoperative analgesia involved preemptive intravenous paracetamol and morphine as needed. MEASUREMENTS AND MAIN RESULTS: No anesthesia-related or implantation-related complications were observed, with a mean procedure duration of 112 ± 44 minutes. The median hospital stay was 4 days, and only 1 patient required brief intensive care unit monitoring. Postoperative right shoulder pain was reported by half of the patients, and was managed with morphine bolus administration (average dose 4.75 ± 3.6 mg). All patients had the device correctly positioned, as confirmed by postoperative transthoracic echocardiograms. None of the patients required outpatient analgesic therapy upon discharge. CONCLUSIONS: The authors' study demonstrated the potential of TricValve implantation in effectively managing severe tricuspid regurgitation with no procedure-related complications and a 100% survival rate. A collaborative, interdisciplinary approach and targeted anesthesia management proved crucial for this success. Postoperative shoulder pain emerged as a frequent complication, whose pathogenesis is still not clear, and successfully was managed using targeted analgesic therapy.

Macklin Effect: From Pathophysiology to Clinical Implication.

Air leak syndromes (such as pneumomediastinum, pneumothorax, or subcutaneous emphysema) are frequent complications of acute respiratory distress syndrome (ARDS). Unfortunately, the development of air leaks is associated with worse outcomes. In addition, it has been hypothesized that the development of pneumomediastinum could be a marker of disease severity in patients with respiratory failure receiving noninvasive respiratory support or assisted ventilation. The so-called Macklin effect (or pulmonary interstitial emphysema) is the air dissection of the lung bronchovascular tree from peripheral to central airways following injury to distal alveoli. Ultimately, the progression of the Macklin effect leads to the development of pneumomediastinum, subcutaneous emphysema, or pneumothorax. The Macklin effect is identifiable on a chest computed tomography (CT) scan. The Macklin effect could be an accurate predictor of barotrauma in patients with ARDS (sensitivity = 89.2% [95% CI: 74.6-96.9]; specificity = 95.6% [95% CI: 90.6-98.4]), and may be a marker of disease severity. Accordingly, the detection of the Macklin effect on a chest CT scan could be used to select which patients with ARDS might benefit from different treatment algorithms, including advanced respiratory monitoring, early intubation, or, potentially, the institution of early extracorporeal support with or without invasive ventilation. In this video, the authors summarize the pathophysiology and potential clinical significance and applications of the Macklin effect in patients with acute respiratory failure.

Safety of Levosimendan in Pediatric Patients: An Up-to-Date Systematic Review.

BACKGROUND: The potential risks associated with the use of levosimendan in the pediatric population has not been systematically evaluated. This study aimed to review the available evidence regarding the safety of this treatment. METHODS: Bio Med Central, PubMed, Embase, and the Cochrane Central Register of clinical trials were searched for studies describing levosimendan administration in the pediatric population in any setting. Relevant studies were independently screened, selected, and their data extracted by two investigators. The authors excluded: reviews, meta-analyses, as well as basic research and trials involving patients >18 years old. The primary outcome was the number and the type of adverse side effects reported during levosimendan administration. RESULTS: The updated systematic review included 48 studies, enrolling a total of 1,271 pediatric patients who received levosimendan as treatment (790 patients in the 11 studies that reported side effects). The primary adverse effects of levosimendan administration were hypotension and cardiac arrhythmias, particularly tachycardia. Hypotension occurred in approximately 28.9% of patients, while arrhythmia occurred in about 12.3% of patients. Meta analysis of RCTs revealed a rate of all-cause mortality of 2.0% (8 out of 385) in the levosimendan group compared to 3.9% (15 out of 378) in the control group (dobutamine, milrinone or placebo) (risk ratio [RR] = 0.55; 95% confidence interval [CI] = 0.25-1.21; P = 0.14; I2 = 0%) CONCLUSIONS: Hypotension and cardiac arrhythmia are the most reported side effects of levosimendan in pediatric patients. However, adverse events remain underreported, especially in randomized trials.

Norepinephrine Salt Formulations and Risk of Therapeutic Error: Results of a National Survey.

OBJECTIVES: Norepinephrine is available commercially in solution containing its salt (eg, tartrate), but only the base form (ie, norepinephrine base) is active pharmacologically. Unfortunately, the outer label of drug packages frequently reports the dosage of norepinephrine as a salt, which can lead potentially to therapeutic errors when prescribing norepinephrine. We performed a survey to assess the level of awareness of this issue. DESIGN: National survey. SETTING: Acute care units of Italian hospitals. PARTICIPANTS: Acute care physicians and nurses. INTERVENTIONS: A 15-item online survey was emailed to 305 critical care practitioners in Italy. Questions included information on the participants' background, methods of diluting norepinephrine, interpretation of recommended doses from guidelines, and a sample case related to the preparation and administration of the drug. MEASUREMENTS AND MAIN RESULTS: We collected 106 responses from 54 hospitals. All hospitals used norepinephrine bitartrate salt. Of the participants, 53% responded that the guidelines express norepinephrine dosages as a salt, 23% as the base form, and 24% were unsure or unaware about it. The simulated patient-dose calculation was resolved in 81% of cases with an incorrect calculation referring to the norepinephrine salt and only in 19% referring to the norepinephrine base. CONCLUSIONS: There is significant variability in dosage management of norepinephrine across different hospital units, as well as a lack of knowledge regarding the salt-to-base ratio. Scientific publications (eg, guidelines) should specify whether they are referring to the base or salt form of norepinephrine. The adoption of different labeling and national standards for dilution may decrease the risk of therapeutic errors.

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.

Volatile versus Total Intravenous Anesthesia for Coronary Artery Bypass Graft Surgery: Analysis of 1586 MYRIAD Trial Patients Managed with the Same Perioperative Protocol.

Background: This study investigated the influence of volatile anesthesia (VA) on major complications and mortality in patients undergoing coronary artery bypass graft surgery (CABG). Methods: This post-hoc analysis included 1586 patients from the MYRIAD trial managed using the same perioperative protocol at a single institution. Patients were randomized to receive either volatile anesthesia (sevoflurane, isoflurane, or desflurane) or total intravenous anesthesia (TIVA). The assessed study outcomes were the rate of complications, including: myocardial infarction, stroke, acute kidney injury, prolonged ventilation ( > 24 h), receipt of high-dose inotropic support (inotropic score > 10), and need for mechanical circulatory support. The duration of intensive care unit (ICU) stay, length of hospitalization, hospital readmission during follow-up, 30-days and 1-year mortality were also analyzed. Results: 1586 patients were enrolled between September 2014-September 2017 and randomly assigned to the volatile anesthesia group (n = 794) and the TIVA group (n = 792). The median patient age was 63 years, with a median ejection fraction of 60%. There were no significant differences in the rates of major complications, duration of ICU stay, and hospitalization between the groups. The median total dose of fentanyl was 12.0 mcg/kg in volatile group and 14.4 mcg/kg in TIVA group (p < 0.001). One-year mortality rates were 2.5% (n = 20) and 3.2% (n = 25) in the volatile and TIVA groups, respectively. Two patients were lost at the 30-day and 1-year follow-ups in the volatile group compared to four patients in TIVA group. Regression analysis showed that cardiopulmonary bypass (CPB) duration, fentanyl dose, and baseline serum creatinine level were associated with 30-days mortality, while ejection fraction was associated with 1-year mortality. Conclusions: The use of VA in patients undergoing CABG did not result in a reduction in major complications or mortality compared with TIVA. A higher dose of fentanyl was used in the TIVA group and was associated with an increase in the 30-days mortality. These findings warrant further investigation. Clinical Trial Registration: ClinicalTrials.gov (NCT02105610).

Acute normovolemic hemodilution in cardiac surgery: Rationale and design of a multicenter randomized trial.

BACKGROUND: Minimizing the use of blood component can reduce known and unknown blood transfusion risks, preserve blood bank resources, and decrease healthcare costs. Red Blood Cell (RBC) transfusion is common after cardiac surgery and associated with adverse perioperative outcomes, including mortality. Acute normovolemic hemodilution (ANH) may reduce bleeding and the need for blood product transfusion after cardiac surgery. However, its blood-saving effect and impact on major outcomes remain uncertain. METHODS: This is a single-blinded, multinational, pragmatic, randomized controlled trial with a 1:1 allocation ratio conducted in Tertiary and University hospitals. The study is designed to enroll patients scheduled for elective cardiac surgery with planned cardiopulmonary bypass (CPB). Patients are randomized to receive ANH before CPB or the best available treatment without ANH. We identified an ANH volume of at least 650 ml as the critical threshold for clinically relevant benefits. Larger ANH volumes, however, are allowed and tailored to the patient's characteristics and clinical conditions. RESULTS: The primary outcome is the percentage of patients receiving RBCs transfusion from randomization until hospital discharge, which we hypothesize will be reduced from 35% to 28% with ANH. Secondary outcomes are all-cause 30-day mortality, acute kidney injury, bleeding complications, and ischemic complications. CONCLUSION: The trial is designed to determine whether ANH can safely reduce RBC transfusion after elective cardiac surgery with CPB. STUDY REGISTRATION: This trial was registered on ClinicalTrials.gov in April 2019 with the trial identification number NCT03913481.