Lung Ultrasonography and Cardiac Surgery: A Narrative Review.

Pulmonary complications are common after cardiac surgery and are closely related to postoperative heart failure and adverse outcomes. Lung ultrasonography (LUS) is currently a widely accepted diagnostic approach with well-established methodology, nomenclature, accuracy, and prognostic value in numerous clinical conditions. The advantages of LUS are universally recognized and include bedside applicability, high diagnostic sensitivity and reproducibility, no radiation exposure, and low cost. However, routine perioperative ultrasonography during cardiac surgery generally is limited to echocardiography, diagnosis of pleural effusion, and as a diagnostic tool for postoperative complications in different organs, and few studies have explored the clinical outcomes in relation to LUS among cardiac patients. This narrative review presents the clinical evidence regarding LUS application in intensive care and during the perioperative period for cardiac surgery. Furthermore, this review describes the methodology and the diagnostic and prognostic accuracies of LUS. A summary of ongoing clinical trials evaluating the clinical outcomes related to LUS also is provided. Finally, this review discusses the rationale for upcoming clinical research regarding whether routine use of LUS can modify current intensive care practice and potentially affect the clinical outcomes after cardiac surgery.

History and Current Status of Cardiac Anesthesiology in Russia.

Anesthesiology, the branch of medicine concerning anesthesia and management of the vital functions of patients undergoing surgery, has played an important role in the development of cardiac surgery. In the middle of the last century, medical professionals had little experience in the treatment of congenital and acquired heart diseases. Progress of cardiac anesthesiology in Russia, as well as in countries across the globe, was due to requests to increase the safety of surgical procedures and to improve survival rates for the increasing number of patients with complex heart diseases. The development of cardiac surgery and anesthesiology in Russia evolved in 2 directions simultaneously in the mid-1950s. Some surgeons widely accepted the use of perfusionless hypothermia (hypothermia caused by surface cooling without perfusion); others were in favor of cardiopulmonary bypass technology. This review focuses on major historic milestones of cardiac anesthesiology in Russia, including its current status and the major problems it faces today.

Hypothermic versus normothermic cardiopulmonary bypass in patients with valvular heart disease.

OBJECTIVE: The aim of this study was to test the hypothesis that normothermic cardiopulmonary bypass (CPB) is as effective as hypothermic CPB in terms of cardiac protection (cTnI level) and outcome in patients with valvular heart disease. DESIGN: Prospective randomized study. SETTING: A tertiary cardiothoracic referral center. PARTICIPANTS: 140 patients who had valvular heart disease, with/without coronary artery disease, surgically treated under CPB. INTERVENTIONS: The patients were allocated randomly to undergo either hypothermic (temperature [T], 31 °C-32 °C) or normothermic CPB (T>36 °C). MEASUREMENTS AND MAIN RESULTS: The primary endpoint was the dynamics of troponin I. The secondary endpoints were ventilation time, the need for inotropic support, intensive care unit (ICU) and hospital stay durations, complications, and mortality. There were no significant intergroup differences in dynamics of troponin I. Ventilation time was significantly lower in the hypothermic group (6 (5-9) and 8 (5-12); p = 0.01). CONCLUSIONS: Normothermic CPB in patients with valvular heart disease was as effective as hypothermic perfusion in terms of myocardial protection after the surgery assessed by cTnI release. The short ventilation duration in patients who underwent hypothermic CPB needs to be confirmed in a future investigation.

Randomized trial of fish oil infusion to prevent atrial fibrillation after cardiac surgery: data from an implantable continuous cardiac monitor.

OBJECTIVE: To test the hypothesis that perioperative OMEGA-3 polyunsaturated fatty acid infusion would reduce the incidence of postoperative atrial fibrillation in patients after coronary artery bypass grafting as assessed by an implantable continuous cardiac monitor. DESIGN: Prospective, randomized, double-blind, placebo-controlled study. SETTING: Tertiary cardiothoracic referral center. PARTICIPANTS: Thirty-nine patients with coronary artery disease who underwent surgery with cardiopulmonary bypass. INTERVENTIONS: Patients were assigned randomly to receive either OMEGA-3 polyunsaturated fatty acids (200 mg/kg/day starting before anesthesia induction for 24 hours followed by 100 mg/kg/day for 7 days) or placebo. The primary outcome was freedom from atrial fibrillation at 2-year follow-up. Reveal(®) cardiac monitor was implanted subcutaneously in all patients. Data from the cardiac monitor were collected on the 10th day and 3, 6, 12, and 24 months postoperatively. MEASUREMENT AND MAIN RESULTS: Postoperative atrial fibrillation developed in 4 (19%) patients in the control group and in 5 (27.8%) patients in the study group at 10-day follow-up (p = 0.88). At 2-year follow-up, 5 (27.8%) patients in the control group and 6 (35.3%) patients in the study group had atrial fibrillation (p = 0.9). Atrial fibrillation duration predicted risk of cardiovascular hospitalization at the 2-year follow-up (regression coefficient estimate = 0.24, standard error 0.02, p<0.0001; R(2) = 0.74). CONCLUSIONS: Infusion of OMEGA-3 polyunsaturated fatty acids failed to prevent the occurrence of atrial fibrillation in 2 years after coronary artery bypass grafting surgery. The cumulative atrial fibrillation duration registered by the continuous cardiac monitor at the 2-year follow-up was a significant predictor of an adverse outcome.

Mortality prediction in patients with dialysis-dependent acute kidney injury after cardiac surgery with cardiopulmonary bypass.

BACKGROUND: To build a predictive model for patients with dialysis-dependent acute kidney injury (AKI-D) after cardiac surgery with the cardiopulmonary bypass (CPB), according to disease severity. METHODS: A single-centre, retrospective cohort study was performed to determine the demographic and clinical parameters (including the specific factor, CPB duration) for risk of poor outcome in patients requiring RRT after cardiac surgery with CPB. A new model was built for mortality prediction in these patients on the basis of the identified risk factors and Sequential Organ Failure Assessment score. RESULTS: The newly developed model showed good discriminatory ability for predicting death in patients with AKI-D after cardiac surgery with CPB. The area under the receiver-operating characteristic (ROC) curve for the score was 0.892 (95% confidence interval, 0.852-0.925). We also determined the criterion for the choice of RRT modality by applying this model. On applying the new model in intermittent haemodialysis patients, a score of ≤3.2 was found safe for selecting the RRT modality. CONCLUSIONS: The new scoring system was valid and accurate in predicting death for AKI-D patients after open-heart surgery. This system and value for choice of RRT were determined for guidance only, to facilitate decision-making in difficult situations.

Evaluation of nutritional screening tools among patients scheduled for heart valve surgery.

BACKGROUND AND AIM OF THE STUDY: The study aim was to detect the most sensitive nutritional screening tool and to assess its prognostic value with regards to an adverse clinical course in patients with heart valve disease undergoing cardiopulmonary bypass (CPB). METHODS: This prospective cohort study included 441 adult patients who were screened using four nutritional screening tools: Nutritional Risk Screening 2002 (NRS-2002); Malnutrition Universal Screening Tool (MUST); Mini Nutritional Assessment (MNA); and Short Nutritional Assessment Questionnaire (SNAQ). Nutritional assessment was performed using a Subjective Global Assessment (SGA). In-hospital mortality, postoperative complications, and duration of hospital stay were each analyzed. RESULTS: With regards to the detection of malnutrition, the sensitivities of MUST, SNAQ, MNA and NRS-2002 were 100%, 92%, 84.6% and 43.6%, respectively. Malnutrition identified by MUST and MNA were associated with postoperative complications (OR 1.63, p = 0.033 and OR 1.6, p = 0.035) and prolonged hospitalization (OR 1.57, p = 0.048 and OR 1.7, p = 0.02). According to multivariate logistic regression analysis, along with well-known age and duration of CPB, malnutrition identified by MUST and MNA was associated with a risk of development of complications (OR 1.6, p = 0.049 and OR 1.6, p = 0.04, respectively). The sensitivities of SNAQ, MUST, NRS-2002 and MNA with regards to postoperative complications were 26.8%, 28.8%, 10%, and 31.6%, respectively. CONCLUSION: The MUST tool is preferable with regards to the detection of malnutrition. Both, MUST and MNA independently predicted postoperative complications. SNAQ and NRS-2002 proved insensitive with regards to the postoperative course among patients with heart valve disease who were scheduled for cardiothoracic surgery.

Hypertonic solution decreases extravascular lung water in cardiac patients undergoing cardiopulmonary bypass surgery.

OBJECTIVE: To test the hypothesis that the infusion of hypertonic solution would decrease extravascular lung water postoperatively and thus improve pulmonary function. DESIGN: Prospective, randomized, blinded trial. SETTING: Tertiary cardiothoracic referral center. PARTICIPANTS: Twenty-six patients with coronary artery disease who underwent surgery with cardiopulmonary bypass (CPB). INTERVENTIONS: Patients were allocated randomly to receive 4 mL/kg of 7.2% NaCl/hydroxyethyl starch, 200/0.5 (HSH group) or an equal volume of 0.9% NaCl (control group) for 30 minutes starting after anesthesia induction. The extravascular lung water index, hemodynamic and biochemical data, and the rate of complications were analyzed. MEASUREMENTS AND MAIN RESULTS: The extravascular lung water index was significantly lower (7 v 9.5 mL/kg) in the HSH group at the first postoperative day (p < 0.01). The index of arterial oxygenation efficiency was significantly higher at 5 minutes and 2 and 4 hours after cardiopulmonary bypass (CPB) in the HSH group (p < 0.05). The alveolar-arterial oxygen tension difference was significantly lower at 5 minutes and 2 and 4 hours after CPB in the HSH group (p < 0.01). The cardiac index was significantly higher at 5 minutes after infusion in the HSH group (p < 0.05). CONCLUSIONS: The infusion of HSH leads to significant decreases in the extravascular lung water index during and after cardiac surgery and is associated with better preservation of pulmonary function and transient increases in the cardiac index. Further trials are needed to clarify the clinical advantages of hypertonic solution administration in patients undergoing surgery with CPB.

Methylprednisolone use is associated with endothelial cell activation following cardiac surgery.

BACKGROUND: The objective of this study was to investigate the effect of the perioperative use of methylprednisolone in medium doses on markers of endothelial cell activation in patients with coronary artery disease undergoing cardiopulmonary bypass. METHODS: In this prospective, double-blinded, placebo-controlled, randomised study, 44 patients, undergoing a coronary artery bypass graft surgery received either methylprednisolone 20 mg/kg or a placebo intraoperatively after anaesthesia induction. The primary endpoint was endothelin-1, and secondary endpoints were E-selectin, interleukin (IL)-6 and IL-10, PaO(2)/FiO(2) coefficient, and microalbuminuria. RESULTS: Endothelin-1 was higher in the study group postoperatively at 10 min (p=0.0008), 2 h (p=0.02), 4 h (p=0.005), and 24 h (p=0.004). IL-6 was lower in the study group postoperatively at 2 h (p=0.03), 4 h (p=0.04), and 24 h (p<0.0001). IL-10 was higher in the study group postoperatively at 10 min (p<0.0001), 2 h (p=0.009), and 4 h (p=0.001). PaO(2)/FiO(2) was lower in the study group at 24 h after surgery (p=0.03). Microalbuminuria was similar in both groups. CONCLUSION: Despite an obvious anti-inflammatory effect, methylprednisolone causes endothelial cell activation in patients undergoing cardiopulmonary bypass.

Does glutamine promote benefits for patients with diabetes mellitus scheduled for cardiac surgery?

BACKGROUND: We hypothesised, that perioperative use of N(2)-L-alanyl-L-glutamine confers cardioprotection and improves insulin resistance in diabetic patients with coronary artery disease operated under cardiopulmonary bypass. METHODS: This double-blind, placebo-controlled, randomised study included 64 patients with diabetes mellitus type 2 who were scheduled for on-pump coronary artery bypass graft surgery. The protocol group (32 patients) and the control group (32 patients) glutamine (0.4 g/kg/day of 20% solution of N(2)-L-alanyl-L-glutamine ("Dipeptiven(®)" Fresenius Kabi, Germany)) and placebo (0.9% NaCl), respectively. Perioperative concentration of troponin I in plasma was considered as the primary end-point. Whereas the secondary end-points were insulin resistance, insulin sensitivity, ß-cell function, blood glucose, plasma triglycerides and free fatty acids concentrations. Insulin resistance, insulin sensitivity and ß-cell function were measured using HOMA equation. Thermodilution method was used to measure haemodynamics in all the patients. RESULTS: No differences have been found in perioperative dynamics of troponin I, insulin resistance, insulin sensitivity, ß-cell function, blood glucose, plasma triglycerides free fatty acids concentrations and haemodynamics. CONCLUSION: Our results have failed to confirm the cardioprotective properties and modulatory effect on perioperative insulin resistance that are thought to be attributable to parenteral glutamine administration in dose 0.4 g/kg/day among cardiac patients with DM operated on under CPB.

Levosimendan versus an intra-aortic balloon pump in high-risk cardiac patients.

OBJECTIVE: To test the hypothesis that levosimendan is more effective than intra-aortic balloon pump (IABP) support in cardiac surgical patients with low left ventricular ejection fraction to decrease cardiac troponin I levels (primary endpoint) and improve hemodynamics. DESIGN: Prospective randomized trial. SETTING: Tertiary cardiothoracic referral center. PARTICIPANTS: Ninety patients with coronary artery disease and left ventricular ejection fraction <35% who underwent surgery with cardiopulmonary bypass. INTERVENTION: Patients were assigned randomly to 1 of 3 groups. Group A received a prophylactic IABP one day before surgery. Group B received a prophylactic IABP one day before surgery and a levosimendan infusion at a dose of 0.1 µg/kg/min with an initial bolus (12 µg/kg for 10 minutes) after anesthesia induction. Group C received a levosimendan infusion at a dose of 0.1 µg/kg/min with an initial bolus (12 µg/kg for 10 minutes) after anesthesia induction. Hemodynamic and biochemical data and rate of complications were analyzed. MEASUREMENTS AND MAIN RESULTS: The cardiac troponin I level in group C 6 hours after surgery was lower than in group A (p = 0.048). The cardiac index in group A was significantly lower than in groups B and C. The intensive care unit stay was significantly shorter in group C than in groups A and B (p = 0.001). The need for inotropic support, the rate of complications, and mortality among groups did not differ. CONCLUSIONS: The infusion of levosimendan after anesthesia induction in cardiac surgical patients contributes to lower cardiac troponin I levels and improved hemodynamics compared with a preoperative IABP.

Preoperative total lymphocyte count in peripheral blood as a predictor of poor outcome in adult cardiac surgery.

OBJECTIVE: The aim of this study was to investigate the prognostic value of the preoperative total lymphocyte count in peripheral blood as a predictor of postoperative complications and mortality in cardiac surgery. DESIGN: A retrospective, observational study. SETTING: The Novosibirsk State Research Institute of Circulation Pathology (single institution). PARTICIPANTS: All adults undergoing primary cardiopulmonary bypass in 2009. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The cohort size was 1,368 patients operated upon with cardiopulmonary bypass. Patient characteristics, hospital mortality, postoperative complications, ventilation time, intensive care unit, and hospital stay were analyzed. A preoperative total lymphocyte count <1,500 cells/µL was associated with significantly higher mortality by univariate (p < 0.0001) and multivariate (p < 0.044) analyses. A low preoperative total lymphocyte count was associated with more frequent inotropic support (p < 0.001); postoperative heart arrhythmia (p < 0.001); dialysis-dependent acute renal failure (p < 0.001); and a prolonged ventilation time (p = 0.001), intensive care unit stay (p < 0.001), and hospital stay (p = 0.007). CONCLUSIONS: A low preoperative total lymphocyte count in peripheral blood is a useful prognostic criterion for the evaluation of a complicated postoperative period in cardiac patients operated under cardiopulmonary bypass.

Glutamine is cardioprotective in patients with ischemic heart disease following cardiopulmonary bypass.

BACKGROUND: The aim of the present study was to investigate the cardioprotective effects of the perioperative use of N(2)-L-alanyl-L-glutamine (GLN) in patients with ischemic heart disease (IHD) who undergo their operations under cardiopulmonary bypass (CPB). METHODS: This double-blind, placebo-controlled, randomized study included 50 patients who underwent cardiac surgery with CPB. Exclusion criteria were a left ventricular ejection fraction <50%, diabetes mellitus, <3 months since the onset of myocardial infarction, and emergency surgery. Patients in the study group (n = 25) received 0.4 g/kg GLN (Dipeptiven, 20% solution) per day. Patients in the control group (n = 25) were administered a placebo (0.9% NaCl). The primary end point was the dynamics of troponin I at the following stages: (1) prior to anesthesia, (2) 30 minutes after CPB, (3) 6 hours after CPB, (4) 24 hours after surgery, and (5) 48 hours after surgery. Secondary end points included measurements of hemodynamics with a Swan-Ganz catheter. RESULTS: On the first postoperative day after the surgery, the median troponin I level was significantly lower in the study group than in the placebo group: 1.280 ng/mL (interquartile range [IQR], 0.840-2.230 ng/mL) versus 2.410 ng/mL (IQR, 1.060-6.600 ng/mL) (P = .035). At 4 hours after cardiopulmonary bypass (CPB), the median cardiac index was higher in the patients in the study group: 2.58 L/min per m2 (IQR, 2.34-2.91 L/min per m2) versus 2.03 L/min per m2 (IQR, 1.76-2.32 L/min per m2) (P = .002). The median stroke index also was higher in the patients who received GLN: 32.8 mL/m2 (IQR, 27.8-36.0 mL/m2) versus 26.1 mL/m2 (IQR, 22.6-31.8 mL/m2) (P = .023). The median systemic vascular resistance index was significantly lower in the study group than in the placebo group: 1942 dyn·s/cm5 per m2 (IQR, 1828-2209 dyn·s/cm5 per m2) versus 2456 dyn·s/cm5 per m2 (IQR, 2400-3265 dyn·s/cm5 per m2) (P = .001). CONCLUSION: Perioperative administration of GLN during the first 24 hours has cardioprotective effects in IHD patients following CPB. This technique enhances the troponin concentration at 24 hours after surgery and is associated with improved myocardial function.

Impact of malnutrition on survival in adult patients after elective cardiac surgery: Long-term follow up data.

The data article refers to the paper titles "Impact of malnutrition on long-term survival in adult patients after elective cardiac surgery" [1]. The data refer to the analysis of the relationship between baseline malnutrition and long-term mortality after cardiac surgery. Baseline demographic, nutritional, and medical history data were collected for each enrolled patient. Baseline serum albumin and C-reactive (CRP) protein levels were also obtained. Surgical risk was assessed in accordance with the logistic EuroSCORE. Intraoperative data including cardiopulmonary bypass (CPB) time and postoperative characteristics, such as postoperative complications, number of days in the ICU, and hospitalization duration, were also collected. Data on nutritional status were collected using four nutritional screening tools: (1) malnutrition universal screening tool (MUST), (2) short nutritional assessment questionnaire (SNAQ), (3) mini-nutritional assessment (MNA), and (4) nutritional risk screening 2002 (NRS-2002). Both electronic medical records and phone interviews were used for survival data collection. ROC analysis was performed to analyze prognostic value of baseline and perioperative variables on long-term mortality. Univariate and multivariate logistic regression analysis of predictors of 3- and 8-year mortality were performed. Kaplan-Meyer curves, describing the impact of baseline and perioperative characteristics on 3- and 8-year survival were also performed.

Effects of malnutrition on long-term survival in adult patients after elective cardiac surgery.

OBJECTIVES: The aim of this study was to investigate the relationship between malnutrition and long-term survival in patients who underwent cardiopulmonary bypass (CPB). METHODS: This study analyzed the long-term survival data of a mixed cohort of 1187 cardiac patients previously enrolled in a prospective observational study of nutritional screening in cardiac surgery. Nutritional status was assessed using the Malnutrition Universal Screening Tool (MUST). The mean age of patients was 58.86 ± 10.07 y (95% confidence interval [CI], 58.2-59.4). The median time of follow-up was 73.4 mo (25th-75th percentiles, 18.3-101.3). RESULTS: In all, 449 patients (37.8%) were lost to follow-up after hospitalization. For the remaining participants, the overall 8-y survival was 68% (95% CI, 59-76) and 77% (95% CI, 73-80; log-rank, P = 0.12) in patients with and without malnutrition risk, respectively. Statistically significant differences in survival were found during the 3-y follow-up of patients with heart valve disease: 83% (95% CI, 74-92) with malnutrition versus 93% (95% CI, 90-96) without malnutrition (log-rank, P = 0.03). The final multivariate Cox regression model revealed logistic EuroSCORE (hazard ratio (HR), 1.337; 95% CI, 1.110-1.612), cardiopulmonary bypass time <110.5 min (HR 0.463, 95% CI 0.255-0.842), preoperative albumin (HR 0.799, 95% CI 0.691-0.924), and C-reactive protein (HR, 1.106; 95% CI, 1.018-1.202) as independent predictors of 3-y survival. CONCLUSION: Preoperative malnutrition is not associated with 8-y mortality in a mixed cardiac surgery cohort. However, it may be associated with worse 3-y outcomes in patients with heart valve disease.

Prediction of Prolonged ICU Stay in Cardiac Surgery Patients as a Useful Method to Identify Nutrition Risk in Cardiac Surgery Patients: A Post Hoc Analysis of a Prospective Observational Study.

BACKGROUND: Cardiovascular surgery patients with a prolonged intensive care unit (ICU) stay may benefit most from early nutrition support. Using established scoring systems for nutrition assessment and operative risk stratification, we aimed to develop a model to predict a prolonged ICU stay ≥5 days in order to identify patients who will benefit from early nutrition interventions. METHODS: This is a retrospective analysis of a prospective observational study of patients undergoing elective valvular, coronary artery bypass grafting, or combined cardiac surgery. The nutrition risk was assessed by well-established screening tools. Patients' preoperative EuroSCORE (European System for Cardiac Operative Risk Evaluation), primary disease, and intraoperative cardiopulmonary bypass (CPB) time were included as independent variables in a multivariate logistic regression analysis to predict a prolonged ICU stay (>4 days). RESULTS: The number of cardiac surgery patients included was 1193. Multivariate analysis revealed that for prediction of ICU stay >4 days, both Nutritional Risk Screening 2002 (area under the curve (AUC): 0.716, P = .020) and Mini Nutritional Assessment (MNA) score (AUC: 0.715, P = .037) were significant, whereas for prediction of ICU stay >5 days, only the MNA score showed significant results (AUC: 0.762, P = .011). CONCLUSION: Present data provide first evidence about the combined use of EuroSCORE, primary disease, CPB time, and nutrition risk screening tools for prediction of prolonged ICU stay in cardiac surgery patients. If prospectively evaluated in adequately designed studies, this model may help to identify patients with prolonged ICU stay to initiate early postoperative nutrition therapy and thus, facilitate an enhanced recovery.