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.

TREATMENT WITH HUMAN UMBILICAL CORD-DERIVED MESENCHYMAL STEM CELLS IN A PIG MODEL OF SEPSIS-INDUCED ACUTE KIDNEY INJURY: EFFECTS ON MICROVASCULAR ENDOTHELIAL CELLS AND TUBULAR CELLS IN THE KIDNEY.

ABSTRACT: Background: Approximately 50% of patients with sepsis develop acute kidney injury (AKI), which is predictive of poor outcomes, with mortality rates of up to 70%. The endothelium is a major target for treatments aimed at preventing the complications of sepsis. We hypothesized that human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) could attenuate tubular and endothelial injury in a porcine model of sepsis-induced AKI. Methods: Anesthetized pigs were induced to fecal peritonitis, resulting in septic shock, and were randomized to treatment with fluids, vasopressors, and antibiotics (sepsis group; n = 11) or to that same treatment plus infusion of 1 × 10 6 cells/kg of hUC-MSCs (sepsis+MSC group; n = 11). Results: At 24 h after sepsis induction, changes in serum creatinine and mean arterial pressure were comparable between the two groups, as was mortality. However, the sepsis+MSC group showed some significant differences in comparison with the sepsis group: lower fractional excretions of sodium and potassium; greater epithelial sodium channel protein expression; and lower protein expression of the Na-K-2Cl cotransporter and aquaporin 2 in the renal medulla. Expression of P-selectin, thrombomodulin, and vascular endothelial growth factor was significantly lower in the sepsis+MSC group than in the sepsis group, whereas that of Toll-like receptor 4 (TLR4) and nuclear factor-kappa B (NF-κB) was lower in the former. Conclusion: Treatment with hUC-MSCs seems to protect endothelial and tubular cells in sepsis-induced AKI, possibly via the TLR4/NF-κB signaling pathway. Therefore, it might be an effective treatment for sepsis-induced AKI.

Perioperative blood transfusion decreases long-term survival in pediatric living donor liver transplantation.

BACKGROUND: The impact of perioperative blood transfusion on short- and long-term outcomes in pediatric living donor liver transplantation (PLDLT) must still be ascertained, mainly among young children. Clinical and surgical postoperative complications related to perioperative blood transfusion are well described up to three months after adult liver transplantation. AIM: To determine whether transfusion is associated with early and late postoperative complications and mortality in small patients undergoing PLDLT. METHODS: We evaluated the effects of perioperative transfusion on postoperative complications in recipients up to 20 kg of body weight, submitted to PLDLT. A total of 240 patients were retrospectively allocated into two groups according to postoperative complications: Minor complications (n = 109) and major complications (n = 131). Multiple logistic regression analysis identified the volume of perioperative packed red blood cells (RBC) transfusion as the only independent risk factor for major postoperative complications. The receiver operating characteristic curve was drawn to identify the optimal volume of the perioperative RBC transfusion related to the presence of major postoperative complications, defining a cutoff point of 27.5 mL/kg. Subsequently, patients were reallocated to a low-volume transfusion group (LTr; n = 103, RBC ≤ 27.5 mL/kg) and a high-volume transfusion group (HTr; n = 137, RBC > 27.5 mL/kg) so that the outcome could be analyzed. RESULTS: High-volume transfusion was associated with an increased number of major complications and mortality during hospitalization up to a 10-year follow-up period. During a short-term period, the HTr showed an increase in major infectious, cardiovascular, respiratory, and bleeding complications, with a decrease in rejection complications compared to the LTr. Over a long-term period, the HTr showed an increase in major infectious, cardiovascular, respiratory, and minor neoplastic complications, with a decrease in rejection complications. Additionally, Cox hazard regression found that high-volume RBC transfusion increased the mortality risk by 3.031-fold compared to low-volume transfusion. The Kaplan-Meier survival curves of the studied groups were compared using log-rank tests and the analysis showed significantly decreased graft survival, but with no impact in patient survival related to major complications. On the other hand, there was a significant decrease in both graft and patient survival, with high-volume RBC transfusion. CONCLUSION: Transfusion of RBC volume higher than 27.5 mL/kg during the perioperative period is associated with a significant increase in short- and long-term postoperative morbidity and mortality after PLDLT.

SARS-CoV-2 pneumonia-receptor binding and lung immunopathology: a narrative review.

The current pandemic of COVID-19 caused thousands of deaths and healthcare professionals struggle to properly manage infected patients. This review summarizes information about SARS-CoV-2 receptor binding dynamics and intricacies, lung autopsy findings, immune response patterns, evidence-based explanations for the immune response, and COVID-19-associated hypercoagulability.

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.

Nebulization of Vancomycin Provides Higher Lung Tissue Concentrations than Intravenous Administration in Ventilated Female Piglets with Healthy Lungs.

BACKGROUND: Intravenous vancomycin is used to treat ventilator-associated pneumonia caused by methicillin-resistant Staphylococcus aureus, but achieves high rates of failure. Vancomycin nebulization may be efficient to provide high vancomycin lung tissue concentrations. The aim of this study was to compare lung tissue and serum concentrations of vancomycin administered intravenously and by aerosol in mechanically ventilated and anesthetized healthy piglets. METHODS: Twelve female piglets received a single intravenous dose of vancomycin (15 mg/kg) and were killed 1 (n = 6) or 12 h (n = 6) after the end of administration. Twelve piglets received a single nebulized dose of vancomycin (37.5 mg/kg) and were killed 1 (n = 6) or 12 h (n = 6) after the end of the aerosol administration. In each group, vancomycin lung tissue concentrations were assessed on postmortem lung specimens using high-performance liquid chromatography. Blood samples were collected for serum vancomycin concentration measurement 30 min and 1, 2, 4, 6, 8, and 12 h after the end of vancomycin administration. Pharmacokinetics was analyzed by nonlinear mixed effect modeling. RESULTS: One hour after vancomycin administration, lung tissue concentrations in the aerosol group were 13 times the concentrations in the intravenous group (median and interquartile range: 161 [71, 301] µg/g versus 12 [4, 42] µg/g; P < 0.0001). Twelve hours after vancomycin administration, lung tissue concentrations in the aerosol group were 63 (23, 119) µg/g and 0 (0, 19) µg/g in the intravenous group (P < 0.0001). A two-compartment weight-scaled allometric model with first-order absorption and elimination best fit serum pharmacokinetics after both routes of administration. Area under the time-concentration curve from 0 to 12 h was lower in the aerosol group in comparison to the intravenous group (56 [8, 70] mg · h · l vs. 121 [103, 149] mg · h · l, P = 0.002). Using a population model, vancomycin bioavailability was 13% (95% CI, 6 to 69; coefficient of variation = 85%) and absorption rate was slow (absorption half life = 0.3 h). CONCLUSIONS: Administration of vancomycin by nebulization resulted in higher lung tissue concentrations than the intravenous route.

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.

Propensity score matching comparison of laparoscopic versus open surgery for rectal cancer in a middle-income country: short-term outcomes and cost analysis.

BACKGROUND: Laparoscopic surgery for rectal cancer is associated with improved postoperative outcomes compared to open surgery; however, economic studies have yielded contradictory results. The aim of this study was to compare the clinical and economic outcomes of laparoscopic versus open surgery for patients with rectal cancer. METHODS: Propensity score matching analysis was performed in a retrospective cohort of patients who underwent elective low anterior resection for rectal cancer treatment by laparoscopic and open surgery in a single Brazilian cancer center. Matched covariates included age, gender, body mass index, pTNM stage, American Society of Anesthesiologists score, type of anesthesia, neoadjuvant chemoradiotherapy, and interval between neoadjuvant chemoradiotherapy and index surgery. The clinical and economic outcomes were evaluated. The follow-up period was within 30 days of the index procedure. The clinical outcomes were reoperation, postoperative complications, operative time, length of stay in the intensive care unit, and postoperative hospital stay. For economic outcomes, a cost analysis was used to compare the costs. RESULTS: Initially, 220 patients were evaluated. After propensity score matching, 100 patients were included in the analysis (50 patients in the open surgery group and 50 patients in the laparoscopic surgery group). There were no differences in patients' baseline characteristics. Operative time was longer for laparoscopic surgery (247 minutes vs 285 minutes, P=0.006). There were no significant differences in other clinical outcomes. The hospital costs were similar between the two groups (Brazilian reais 21,233.15 vs Brazilian reais 21,529.28, P=0.115), although the intraoperative costs were higher for laparoscopic surgery, mainly owing to the surgical devices and the theater-related costs. The postoperative costs were lower for laparoscopic surgery, owing to lower intensive care unit, ward, and reoperation costs. CONCLUSION: Laparoscopic surgery for rectal cancer is not costlier than open surgery from the health care provider's perspective, since the intraoperative costs were offset by lower postoperative costs. Open surgery tends to have a longer length of stay.

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.

A pragmatic multi-center trial of goal-directed fluid management based on pulse pressure variation monitoring during high-risk surgery.

BACKGROUND: Intraoperative fluid therapy guided by mechanical ventilation-induced pulse-pressure variation (PPV) may improve outcomes after major surgery. We tested this hypothesis in a multi-center study. METHODS: The patients were included in two periods: a first control period (control group; n = 147) in which intraoperative fluids were given according to clinical judgment. After a training period, intraoperative fluid management was titrated to maintain PPV < 10% in 109 surgical patients (PPV group). We performed 1:1 propensity score matching to ensure the groups were comparable with regard to age, weight, duration of surgery, and type of operation. The primary endpoint was postoperative hospital length of stay. RESULTS: After matching, 84 patients remained in each group. Baseline characteristics, surgical procedure duration and physiological parameters evaluated at the start of surgery were similar between the groups. The volume of crystalloids (4500 mL [3200-6500 mL] versus 5000 mL [3750-8862 mL]; P = 0.01), the number of blood units infused during the surgery (1.7 U [0.9-2.0 U] versus 2.0 U [1.7-2.6 U]; P = 0.01), the fraction of patients transfused (13.1% versus 32.1%; P = 0.003) and the number of patients receiving mechanical ventilation at 24 h (3.2% versus 9.7%; P = 0.027) were smaller postoperatively in PPV group. Intraoperative PPV-based improved the composite outcome of postoperative complications OR 0.59 [95% CI 0.35-0.99] and reduced the postoperative hospital length of stay (8 days [6-14 days] versus 11 days [7-18 days]; P = 0.01). CONCLUSIONS: In high-risk surgeries, PPV-directed volume loading improved postoperative outcomes and decreased the postoperative hospital length of stay. TRIAL REGISTRATION: ClinicalTrials.gov Identifier; retrospectively registered- NCT03128190.

Effect of Intensive vs Moderate Alveolar Recruitment Strategies Added to Lung-Protective Ventilation on Postoperative Pulmonary Complications: A Randomized Clinical Trial.

Importance: Perioperative lung-protective ventilation has been recommended to reduce pulmonary complications after cardiac surgery. The protective role of a small tidal volume (VT) has been established, whereas the added protection afforded by alveolar recruiting strategies remains controversial. Objective: To determine whether an intensive alveolar recruitment strategy could reduce postoperative pulmonary complications, when added to a protective ventilation with small VT. Design, Setting, and Participants: Randomized clinical trial of patients with hypoxemia after cardiac surgery at a single ICU in Brazil (December 2011-2014). Interventions: Intensive recruitment strategy (n=157) or moderate recruitment strategy (n=163) plus protective ventilation with small VT. Main Outcomes and Measures: Severity of postoperative pulmonary complications computed until hospital discharge, analyzed with a common odds ratio (OR) to detect ordinal shift in distribution of pulmonary complication severity score (0-to-5 scale, 0, no complications; 5, death). Prespecified secondary outcomes were length of stay in the ICU and hospital, incidence of barotrauma, and hospital mortality. Results: All 320 patients (median age, 62 years; IQR, 56-69 years; 125 women [39%]) completed the trial. The intensive recruitment strategy group had a mean 1.8 (95% CI, 1.7 to 2.0) and a median 1.7 (IQR, 1.0-2.0) pulmonary complications score vs 2.1 (95% CI, 2.0-2.3) and 2.0 (IQR, 1.5-3.0) for the moderate strategy group. Overall, the distribution of primary outcome scores shifted consistently in favor of the intensive strategy, with a common OR for lower scores of 1.86 (95% CI, 1.22 to 2.83; P = .003). The mean hospital stay for the moderate group was 12.4 days vs 10.9 days in the intensive group (absolute difference, -1.5 days; 95% CI, -3.1 to -0.3; P = .04). The mean ICU stay for the moderate group was 4.8 days vs 3.8 days for the intensive group (absolute difference, -1.0 days; 95% CI, -1.6 to -0.2; P = .01). Hospital mortality (2.5% in the intensive group vs 4.9% in the moderate group; absolute difference, -2.4%, 95% CI, -7.1% to 2.2%) and barotrauma incidence (0% in the intensive group vs 0.6% in the moderate group; absolute difference, -0.6%; 95% CI, -1.8% to 0.6%; P = .51) did not differ significantly between groups. Conclusions and Relevance: Among patients with hypoxemia after cardiac surgery, the use of an intensive vs a moderate alveolar recruitment strategy resulted in less severe pulmonary complications while in the hospital. Trial Registration: clinicaltrials.gov Identifier: NCT01502332.

Liberal Versus Restrictive Transfusion Strategy in Critically Ill Oncologic Patients: The Transfusion Requirements in Critically Ill Oncologic Patients Randomized Controlled Trial.

OBJECTIVE: To assess whether a restrictive strategy of RBC transfusion reduces 28-day mortality when compared with a liberal strategy in cancer patients with septic shock. DESIGN: Single center, randomized, double-blind controlled trial. SETTING: Teaching hospital. PATIENTS: Adult cancer patients with septic shock in the first 6 hours of ICU admission. INTERVENTIONS: Patients were randomized to the liberal (hemoglobin threshold, < 9 g/dL) or to the restrictive strategy (hemoglobin threshold, < 7 g/dL) of RBC transfusion during ICU stay. MEASUREMENTS AND MAIN RESULTS: Patients were randomized to the liberal (n = 149) or to the restrictive transfusion strategy (n = 151) group. Patients in the liberal group received more RBC units than patients in the restrictive group (1 [0-3] vs 0 [0-2] unit; p < 0.001). At 28 days after randomization, mortality rate in the liberal group (primary endpoint of the study) was 45% (67 patients) versus 56% (84 patients) in the restrictive group (hazard ratio, 0.74; 95% CI, 0.53-1.04; p = 0.08) with no differences in ICU and hospital length of stay. At 90 days after randomization, mortality rate in the liberal group was lower (59% vs 70%) than in the restrictive group (hazard ratio, 0.72; 95% CI, 0.53-0.97; p = 0.03). CONCLUSIONS: We observed a survival trend favoring a liberal transfusion strategy in patients with septic shock when compared with the restrictive strategy. These results went in the opposite direction of the a priori hypothesis and of other trials in the field and need to be confirmed.

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.

Sevoflurane preconditioning during myocardial ischemia-reperfusion reduces infarct size and preserves autonomic control of circulation in rats.

PURPOSE: To investigate the myocardial ischemia-reperfusion with sevoflurane anesthetic preconditioning (APC) would present beneficial effects on autonomic and cardiac function indexes after the acute phase of a myocardial ischemia-reperfusion. METHODS: Twenty Wistar rats were allocated in three groups: control (CON, n=10), myocardial infarction with sevoflurane (SEV, n=5) and infarcted without sevoflurane (INF, n=5). Myocardial ischemia (60 min) and reperfusion were performed by temporary coronary occlusion. Twenty-one days later, the systolic and diastolic function were evaluated by echocardiography; spectral analysis of the systolic arterial pressure (SAPV) and heart rate variability (HRV) were assessed. After the recording period, the infarct size (IS) was evaluated. RESULTS: The INF group presented greater cardiac dysfunction and increased sympathetic modulation of the SAPV, as well as decreased alpha index and worse vagal modulation of the HRV. The SEV group exhibited attenuation of the systolic and diastolic dysfunction and preserved vagal modulation (square root of the mean squared differences of successive R-R intervals and high frequency) of HRV, as well as a smaller IS. CONCLUSION: Sevoflurane preconditioning better preserved the cardiac function and autonomic modulation of the heart in post-acute myocardial infarction period.

A comparison of the cardiopulmonary effects of pressure controlled ventilation and volume controlled ventilation in healthy anesthetized dogs.

OBJECTIVE: To compare the effects of pressure controlled ventilation (PCV) with volume-controlled ventilation (VCV) on lung compliance, gas exchange, and hemodynamics in isoflurane-anesthetized dogs. DESIGN: Prospective randomized study. SETTING: Veterinary teaching hospital. ANIMALS: Forty client-owned bitches undergoing elective ovariohysterectomy. INTERVENTIONS: Dogs were randomly assigned to be ventilated with 100% oxygen using PCV (n = 20) or VCV (n = 20). The respiratory rate was 20/min and positive end-expiratory pressure (PEEP) was 5 cm H2 O, with a tidal volume of 10 mL/kg. Cardiac output (CO) was measured using thermodilution. Cardiopulmonary and blood gas data were obtained during spontaneous ventilation and after 30 (T30) and 60 minutes (T60) of controlled ventilation. MEASUREMENTS AND MAIN RESULTS: In dogs ventilated with PCV, at T30 and T60, PIP was lower (11.4 ± 1.9 and 11.1 ± 1.5 cm H2 O, respectively) and static compliance (CST ) was higher (51 ± 7 and 56 ± 6 mL/cm H2 O, respectively) than in VCV group (PIP of 14.3 ± 1.3 and 15.5 ± 1.4 cm H2 O; CST of 34 ± 8 and 33 ± 9 mL/cm H2 O, P < 0.0001). Compared with spontaneous ventilation, both groups had decreased alveolar-arterial oxygen difference at T30 and T60 (PCV: 128 ± 32 mm Hg vs 108 ± 20 and 104 ± 16 mm Hg, respectively; VCV: 131 ± 38 mm Hg vs 109 ± 19 and 107 ± 14 mm Hg, respectively; P < 0.01), while CO was maintained at all time points. CONCLUSIONS: Compared to spontaneous ventilation, both ventilatory modes effectively improved gas exchange without hemodynamic impairment. PCV resulted in higher lung CST and lower PIP compared to VCV.

Perioperative cardiac arrest: an evolutionary analysis of the intra-operative cardiac arrest incidence in tertiary centers in Brazil / Parada cardíaca perioperatória: uma análise evolutiva da incidência de parada cardíaca intraoperatória em centros terciários no Brasil

ABSTRACT BACKGROUND: Great changes in medicine have taken place over the last 25 years worldwide. These changes in technologies, patient risks, patient profile, and laws regulating the medicine have impacted the incidence of cardiac arrest. It has been postulated that the incidence of intraoperative cardiac arrest has decreased over the years, especially in developed countries. The authors hypothesized that, as in the rest of the world, the incidence of intraoperative cardiac arrest is decreasing in Brazil, a developing country. OBJECTIVES: The aim of this study was to search the literature to evaluate the publications that relate the incidence of intraoperative cardiac arrest in Brazil and analyze the trend in the incidence of intraoperative cardiac arrest. CONTENTS: There were 4 articles that met our inclusion criteria, resulting in 204,072 patients undergoing regional or general anesthesia in two tertiary and academic hospitals, totalizing 627 cases of intraoperative cardiac arrest. The mean intraoperative cardiac arrest incidence for the 25 years period was 30.72:10,000 anesthesias. There was a decrease from 39:10,000 anesthesias to 13:10,000 anesthesias in the analyzed period, with the related lethality from 48.3% to 30.8%. Also, the main causes of anesthesia-related cause of mortality changed from machine malfunction and drug overdose to hypovolemia and respiratory causes. CONCLUSIONS: There was a clear reduction in the incidence of intraoperative cardiac arrest in the last 25 years in Brazil. This reduction is seen worldwide and might be a result of multiple factors, including new laws regulating the medicine in Brazil, incorporation of technologies, better human development level of the country, and better patient care.

RESUMO JUSTIFICATIVA: Nos últimos 25 anos ocorreram grandes mudanças na medicina em todo o mundo. Essas mudanças de tecnologias, riscos do paciente, perfil do paciente e leis que regulam medicamentos tiveram impacto na incidência de parada cardíaca (PC). Postula-se que a incidência de parada cardíaca intraoperatória (PCI) tem diminuído ao longo dos anos, especialmente em países desenvolvidos. A nossa hipótese foi que, como no resto do mundo, a incidência de PCI está diminuindo no Brasil, um país em desenvolvimento. OBJETIVOS: O objetivo deste estudo foi pesquisar e avaliar na literatura as publicações que relacionam a incidência de PCI no Brasil e analisar a tendência na incidência de PCI. CONTEÚDO: Descobrimos quatro artigos que atenderam aos critérios de inclusão, que resultaram em 204.072 pacientes submetidos à anestesia regional ou geral em dois hospitais terciários e acadêmicos e 627 casos de PCI. A média de incidência de PCI para o período de 25 anos foi de 30,72:10.000 anestesias. Houve uma diminuição de 39:10.000 anestesias para 13:10.000 anestesias no período analisado, com letalidade relacionada de 48,3% para 30,8%. Além disso, as principais causas de mortalidade relacionadas à anestesia mudaram de mau funcionamento de máquinas e overdose de medicamentos para hipovolemia e causas respiratórias. CONCLUSÕES: Houve uma clara redução na incidência de PCI nos últimos 25 anos no Brasil. Essa redução é observada em todo o mundo e pode ser o resultado de vários fatores, incluindo novas leis que regulam medicamentos no Brasil, incorporação de tecnologias, melhor nível de desenvolvimento humano do país e melhor assistência ao paciente.

Perioperative cardiac arrest: an evolutionary analysis of the intra-operative cardiac arrest incidence in tertiary centers in Brazil.

BACKGROUND: Great changes in medicine have taken place over the last 25 years worldwide. These changes in technologies, patient risks, patient profile, and laws regulating the medicine have impacted the incidence of cardiac arrest. It has been postulated that the incidence of intraoperative cardiac arrest has decreased over the years, especially in developed countries. The authors hypothesized that, as in the rest of the world, the incidence of intraoperative cardiac arrest is decreasing in Brazil, a developing country. OBJECTIVES: The aim of this study was to search the literature to evaluate the publications that relate the incidence of intraoperative cardiac arrest in Brazil and analyze the trend in the incidence of intraoperative cardiac arrest. CONTENTS: There were 4 articles that met our inclusion criteria, resulting in 204,072 patients undergoing regional or general anesthesia in two tertiary and academic hospitals, totalizing 627 cases of intraoperative cardiac arrest. The mean intraoperative cardiac arrest incidence for the 25 years period was 30.72:10,000 anesthesias. There was a decrease from 39:10,000 anesthesias to 13:10,000 anesthesias in the analyzed period, with the related lethality from 48.3% to 30.8%. Also, the main causes of anesthesia-related cause of mortality changed from machine malfunction and drug overdose to hypovolemia and respiratory causes. CONCLUSIONS: There was a clear reduction in the incidence of intraoperative cardiac arrest in the last 25 years in Brazil. This reduction is seen worldwide and might be a result of multiple factors, including new laws regulating the medicine in Brazil, incorporation of technologies, better human development level of the country, and better patient care.

[Perioperative cardiac arrest: an evolutionary analysis of the intra-operative cardiac arrest incidence in tertiary centers in Brazil]. / Parada cardíaca perioperatória: uma análise evolutiva da incidência de parada cardíaca intraoperatória em centros terciários no Brasil.

BACKGROUND: Great changes in medicine have taken place over the last 25 years worldwide. These changes in technologies, patient risks, patient profile, and laws regulating the medicine have impacted the incidence of cardiac arrest. It has been postulated that the incidence of intraoperative cardiac arrest has decreased over the years, especially in developed countries. The authors hypothesized that, as in the rest of the world, the incidence of intraoperative cardiac arrest is decreasing in Brazil, a developing country. OBJECTIVES: The aim of this study was to search the literature to evaluate the publications that relate the incidence of intraoperative cardiac arrest in Brazil and analyze the trend in the incidence of intraoperative cardiac arrest. CONTENTS: There were 4 articles that met our inclusion criteria, resulting in 204,072 patients undergoing regional or general anesthesia in two tertiary and academic hospitals, totalizing 627 cases of intraoperative cardiac arrest. The mean intraoperative cardiac arrest incidence for the 25 years period was 30.72:10,000 anesthesias. There was a decrease from 39:10,000 anesthesias to 13:10,000 anesthesias in the analyzed period, with the related lethality from 48.3% to 30.8%. Also, the main causes of anesthesia-related cause of mortality changed from machine malfunction and drug overdose to hypovolemia and respiratory causes. CONCLUSIONS: There was a clear reduction in the incidence of intraoperative cardiac arrest in the last 25 years in Brazil. This reduction is seen worldwide and might be a result of multiple factors, including new laws regulating the medicine in Brazil, incorporation of technologies, better human development level of the country, and better patient care.