Methylene blue as an adjuvant during cardiopulmonary resuscitation: an experimental study in rats.

INTRODUCTION: Methylene Blue (MB) has been shown to attenuate oxidative, inflammatory, myocardial, and neurological lesions during ischemia-reperfusion and has great potential during cardiac arrest. This study aimed to determine the effects of MB combined with epinephrine during cardiac arrest on myocardial and cerebral lesions. METHOD: Thirty-eight male Wistar rats were randomly assigned to four groups: the sham group (SH, n = 5), and three groups subjected to cardiac arrest (n = 11/group) and treated with EPI 20 µg.kg-1 (EPI), EPI 20 µg.kg-1 + MB 2 mg.kg-1 (EPI + MB), or saline 0.9% 0.2 ml (CTL). Ventricular fibrillation was induced by direct electrical stimulation in the right ventricle for 3 minutes, and anoxia was maintained for 5 minutes. Cardiopulmonary Resuscitation (CPR) consisted of medications, ventilation, chest compressions, and defibrillation. After returning to spontaneous circulation, animals were observed for four hours. Blood gas, troponin, oxidative stress, histology, and TUNEL staining measurements were analyzed. Groups were compared using generalized estimating equations. RESULTS: No differences in the Returning of Spontaneous Circulation (ROSC) rate were observed among the groups (EPI: 63%, EPI + MB: 45%, CTL: 40%, p = 0.672). The mean arterial pressure immediately after ROSC was higher in the EPI+MB group than in the CTRL group (CTL: 30.5 [5.8], EPI: 63 [25.5], EPI+MB: 123 [31] mmHg, p = 0.007). Serum troponin levels were high in the CTL group (CTL: 130.1 [333.8], EPI: 3.70 [36.0], EPI + MB: 43.7 [116.31] ng/mL, p < 0.05). CONCLUSION: The coadministration of MB and epinephrine failed to yield enhancements in cardiac or brain lesions in a rodent model of cardiac arrest.

Intraoperative pulmonary hyperdistention estimated by transthoracic lung ultrasound: A pilot study.

INTRODUCTION: Transthoracic lung ultrasound can assess atelectasis reversal and is considered as unable to detect associated hyperdistention. In this study, we describe an ultrasound pattern highly suggestive of pulmonary hyperdistention. METHODS: Eighteen patients with normal lungs undergoing lower abdominal surgery were studied. Electrical impedance tomography was calibrated, followed by anaesthetic induction, intubation and mechanical ventilation. To reverse posterior atelectasis, a recruitment manoeuvre was performed. Positive-end expiratory pressure (PEEP) titration was then obtained during a descending trial - 20, 18, 16, 14, 12, 10, 8, 6 and 4cmH2O. Ultrasound and electrical impedance tomography data were collected at each PEEP level and interpreted by two independent observers. Spearman correlation test and receiving operating characteristic curve were used to compare lung ultrasound and electrical impedance tomography data. RESULTS: The number of horizontal A lines increased linearly with PEEP: from 3 (0, 5) at PEEP 4cmH2O to 10 (8, 13) at PEEP 20cmH2O. The increase number of A lines was associated with a parallel and significant decrease in intercostal space thickness (p=0.001). The lung ultrasound threshold for detecting pulmonary hyperdistention was defined as the number of A lines counted at the PEEP preceding the PEEP providing the best respiratory compliance. Six A lines was the median threshold for detecting pulmonary hyperdistention. The area under the receiving operating characteristic curve was 0.947. CONCLUSIONS: Intraoperative transthoracic lung ultrasound can detect lung hyperdistention during a PEEP descending trial. Six or more A lines detected in normally aerated regions can be considered as indicating lung hyperdistention. TRIAL REGISTRATION: NCT02314845 Registered on ClinicalTrials.gov.

Lactated Ringer's Versus 4% Albumin on Lactated Ringer's in Early Sepsis Therapy in Cancer Patients: A Pilot Single-Center Randomized Trial.

OBJECTIVE: To investigate the effects of the administration of 4% albumin on lactated Ringer's, when compared with lactated Ringer's alone, in the early phase of sepsis in cancer patients. DESIGN: Single-center, randomized, double-blind, controlled-parallel trial. SETTING: A tertiary care university cancer hospital. PATIENTS: Cancer patients with severe sepsis or septic shock. INTERVENTIONS: Between October 2014 and December 2016, patients were randomly assigned to receive either bolus of albumin in a lactated Ringer's solution or lactated Ringer's solution alone during the first 6 hours of fluid resuscitation after intensive care medicine (ICU) admission. Primary outcome was defined as death from any cause at 7 days. Secondary outcomes were defined as death from any cause within 28 days, change in Sequence Organ Failure Assessment scores from baseline to day 7, days alive and free of mechanical ventilation, days alive and free of vasopressor, renal replacement therapy during ICU stay, and length of ICU and hospital stay. MEASUREMENTS AND MAIN RESULTS: A total of 360 patients were enrolled in the trial. At 7 days, 46 of 180 patients (26%) died in the albumin group and 40 of 180 (22%) died in the lactated Ringer's group (p = 0.5). At 28 days, 96 of 180 patients (53%) died in the albumin group and 83 of 180 (46%) died in the lactated Ringer's group (p = 0.2). No significant differences in secondary outcomes were observed. CONCLUSIONS: Adding albumin to early standard resuscitation with lactated Ringer's in cancer patients with sepsis did not improve 7-day survival.

Effect of a Perioperative Intra-Aortic Balloon Pump in High-Risk Cardiac Surgery Patients: A Randomized Clinical Trial.

OBJECTIVES: The aim of this study was to evaluate the efficacy of perioperative intra-aortic balloon pump use in high-risk cardiac surgery patients. DESIGN: A single-center randomized controlled trial and a meta-analysis of randomized controlled trials. SETTING: Heart Institute of São Paulo University. PATIENTS: High-risk patients undergoing elective coronary artery bypass surgery. INTERVENTION: Patients were randomized to receive preskin incision intra-aortic balloon pump insertion after anesthesia induction versus no intra-aortic balloon pump use. MEASUREMENTS AND MAIN RESULTS: The primary outcome was a composite endpoint of 30-day mortality and major morbidity (cardiogenic shock, stroke, acute renal failure, mediastinitis, prolonged mechanical ventilation, and a need for reoperation). A total of 181 patients (mean [SD] age 65.4 [9.4] yr; 32% female) were randomized. The primary outcome was observed in 43 patients (47.8%) in the intra-aortic balloon pump group and 42 patients (46.2%) in the control group (p = 0.46). The median duration of inotrope use (51 hr [interquartile range, 32-94 hr] vs 39 hr [interquartile range, 25-66 hr]; p = 0.007) and the ICU length of stay (5 d [interquartile range, 3-8 d] vs 4 d [interquartile range, 3-6 d]; p = 0.035) were longer in the intra-aortic balloon pump group than in the control group. A meta-analysis of 11 randomized controlled trials confirmed a lack of survival improvement in high-risk cardiac surgery patients with perioperative intra-aortic balloon pump use. CONCLUSIONS: In high-risk patients undergoing cardiac surgery, the perioperative use of an intra-aortic balloon pump did not reduce the occurrence of a composite outcome of 30-day mortality and major complications compared with usual care alone.

Vasopressin versus Norepinephrine in Patients with Vasoplegic Shock after Cardiac Surgery: The VANCS Randomized Controlled Trial.

BACKGROUND: Vasoplegic syndrome is a common complication after cardiac surgery and impacts negatively on patient outcomes. The objective of this study was to evaluate whether vasopressin is superior to norepinephrine in reducing postoperative complications in patients with vasoplegic syndrome. METHODS: This prospective, randomized, double-blind trial was conducted at the Heart Institute, University of Sao Paulo, Sao Paulo, Brazil, between January 2012 and March 2014. Patients with vasoplegic shock (defined as mean arterial pressure less than 65 mmHg resistant to fluid challenge and cardiac index greater than 2.2 l · min · m) after cardiac surgery were randomized to receive vasopressin (0.01 to 0.06 U/min) or norepinephrine (10 to 60 µg/min) to maintain arterial pressure. The primary endpoint was a composite of mortality or severe complications (stroke, requirement for mechanical ventilation for longer than 48 h, deep sternal wound infection, reoperation, or acute renal failure) within 30 days. RESULTS: A total of 330 patients were randomized, and 300 were infused with one of the study drugs (vasopressin, 149; norepinephrine, 151). The primary outcome occurred in 32% of the vasopressin patients and in 49% of the norepinephrine patients (unadjusted hazard ratio, 0.55; 95% CI, 0.38 to 0.80; P = 0.0014). Regarding adverse events, the authors found a lower occurrence of atrial fibrillation in the vasopressin group (63.8% vs. 82.1%; P = 0.0004) and no difference between groups in the rates of digital ischemia, mesenteric ischemia, hyponatremia, and myocardial infarction. CONCLUSIONS: The authors' results suggest that vasopressin can be used as a first-line vasopressor agent in postcardiac surgery vasoplegic shock and improves clinical outcomes.

A liberal strategy of red blood cell transfusion reduces cardiogenic shock in elderly patients undergoing cardiac surgery.

OBJECTIVE: The aim of this study was to compare outcomes in patients undergoing cardiac surgery who are aged 60 years or more or less than 60 years after implementation of a restrictive or a liberal transfusion strategy. METHODS: This is a substudy of the Transfusion Requirements After Cardiac Surgery (TRACS) randomized controlled trial. In this subgroup analysis, we separated patients into those aged 60 years or more (elderly) and those aged less than 60 years randomized to a restrictive or a liberal strategy of red blood cell transfusion. The primary outcome was a composite defined as a combination of 30-day all-cause mortality and severe morbidity. RESULTS: Of the 502 patients included in the Transfusion Requirements After Cardiac Surgery study, 260 (51.8%) were aged 60 years or more and 242 (48.2%) were aged less than 60 years and were included in this study. The primary end point occurred in 11.9% of patients in the liberal strategy group and 16.8% of patients in the restrictive strategy group (P = .254) for those aged 60 years or more and in 6.8% of patients in the liberal strategy group and 5.6% of patients in the restrictive strategy group for those aged less than 60 years (P = .714). However, in the older patients, cardiogenic shock was more frequent in patients in the restrictive transfusion group (12.8% vs 5.2%, P = .031). Thirty-day mortality, acute respiratory distress syndrome, and acute renal injury were similar in the restrictive and liberal transfusion groups in both age groups. CONCLUSIONS: Although there was no difference between groups regarding the primary outcome, a restrictive transfusion strategy may result in an increased rate of cardiogenic shock in elderly patients undergoing cardiac surgery compared with a more liberal strategy. Cardiovascular risk of anemia may be more harmful than the risk of blood transfusion in older patients.