Combined pectoralis and serratus anterior plane blocks with or without liposomal bupivacaine for minimally invasive thoracic surgery: A randomized clinical trial.

BACKGROUND: Minimally invasive thoracic surgery is associated with substantial pain that can impair pulmonary function. Fascial plane blocks may offer a favorable alternative to opioids, but conventional local anesthetics provide a limited duration of analgesia. We therefore tested the primary hypothesis that a mixture of liposomal bupivacaine and plain bupivacaine improves the overall benefit of analgesia score (OBAS) during the first three postoperative days compared to bupivacaine alone. Secondarily, we tested the hypotheses that liposomal bupivacaine improves respiratory mechanics, and decreases opioid consumption. METHODS: Adults scheduled for robotically or video-assisted thoracic surgery with combined ultrasound-guided pectoralis II and serratus anterior plane block were randomized to bupivacaine or bupivacaine combined with liposomal bupivacaine. OBAS was measured on postoperative days 1-3 and was analyzed with a linear mixed regression model. Postoperative respiratory mechanics were estimated using a linear mixed model. Total opioid consumption was estimated with a simple linear regression model. RESULTS: We analyzed 189 patients, of whom 95 were randomized to the treatment group and 94 to the control group. There was no significant treatment effect on total OBAS during the initial three postoperative days, with an estimated geometric mean ratio of 0.93 (95% CI: 0.76, 1.14; p = 0.485). There was no observed treatment effect on respiratory mechanics, total opioid consumption, or pain scores. Average pain scores were low in both groups. CONCLUSIONS: Liposomal bupivacaine did not improve OBAS during the initial postoperative three days following minimally invasive thoracic procedures. Furthermore, there was no improvement in respiratory mechanics, no reduction in opioid consumption, and no decrease in pain scores. Thus, the data presented here does not support the use of liposomal bupivacaine over standard bupivacaine to enhance analgesia after minimally invasive thoracic surgery. SUMMARY STATEMENT: For minimally invasive thoracic procedures, addition of liposomal bupivacaine to plain bupivacaine for thoracic fascial plane blocks does not improve OBAS, reduce opioid requirements, improve postoperative respiratory mechanics, or decrease pain scores.

Video Laryngoscopy vs Direct Laryngoscopy for Endotracheal Intubation in the Operating Room: A Cluster Randomized Clinical Trial.

Importance: Endotracheal tubes are typically inserted in the operating room using direct laryngoscopy. Video laryngoscopy has been reported to improve airway visualization; however, whether improved visualization reduces intubation attempts in surgical patients is unclear. Objective: To determine whether the number of intubation attempts per surgical procedure is lower when initial laryngoscopy is performed using video laryngoscopy or direct laryngoscopy. Design, Setting, and Participants: Cluster randomized multiple crossover clinical trial conducted at a single US academic hospital. Patients were adults aged 18 years or older having elective or emergent cardiac, thoracic, or vascular surgical procedures who required single-lumen endotracheal intubation for general anesthesia. Patients were enrolled from March 30, 2021, to December 31, 2022. Data analysis was based on intention to treat. Interventions: Two sets of 11 operating rooms were randomized on a 1-week basis to perform hyperangulated video laryngoscopy or direct laryngoscopy for the initial intubation attempt. Main Outcomes and Measures: The primary outcome was the number of operating room intubation attempts per surgical procedure. Secondary outcomes were intubation failure, defined as the responsible clinician switching to an alternative laryngoscopy device for any reason at any time, or by more than 3 intubation attempts, and a composite of airway and dental injuries. Results: Among 8429 surgical procedures in 7736 patients, the median patient age was 66 (IQR, 56-73) years, 35% (2950) were women, and 85% (7135) had elective surgical procedures. More than 1 intubation attempt was required in 77 of 4413 surgical procedures (1.7%) randomized to receive video laryngoscopy vs 306 of 4016 surgical procedures (7.6%) randomized to receive direct laryngoscopy, with an estimated proportional odds ratio for the number of intubation attempts of 0.20 (95% CI, 0.14-0.28; P < .001). Intubation failure occurred in 12 of 4413 surgical procedures (0.27%) using video laryngoscopy vs 161 of 4016 surgical procedures (4.0%) using direct laryngoscopy (relative risk, 0.06; 95% CI, 0.03-0.14; P < .001) with an unadjusted absolute risk difference of -3.7% (95% CI, -4.4% to -3.2%). Airway and dental injuries did not differ significantly between video laryngoscopy (41 injuries [0.93%]) vs direct laryngoscopy (42 injuries [1.1%]). Conclusion and Relevance: In this study among adults having surgical procedures who required single-lumen endotracheal intubation for general anesthesia, hyperangulated video laryngoscopy decreased the number of attempts needed to achieve endotracheal intubation compared with direct laryngoscopy at a single academic medical center in the US. Results suggest that video laryngoscopy may be a preferable approach for intubating patients undergoing surgical procedures. Trial Registration: ClinicalTrials.gov Identifier: NCT04701762.

Arterial Hyperoxemia During Cardiopulmonary Bypass Was Not Associated With Worse Postoperative Pulmonary Function: A Retrospective Cohort Study.

BACKGROUND: Arterial hyperoxemia may cause end-organ damage secondary to the increased formation of free oxygen radicals. The clinical evidence on postoperative lung toxicity from arterial hyperoxemia during cardiopulmonary bypass (CPB) is scarce, and the effect of arterial partial pressure of oxygen (Pa o2 ) during cardiac surgery on lung injury has been underinvestigated. Thus, we aimed to examine the relationship between Pa o2 during CPB and postoperative lung injury. Secondarily, we examined the relationship between Pa o2 and global (lactate), and regional tissue malperfusion (acute kidney injury). We further explored the association with regional tissue malperfusion by examining markers of cardiac (troponin) and liver injury (bilirubin). METHODS: This was a retrospective cohort study including patients who underwent elective cardiac surgeries (coronary artery bypass, valve, aortic, or combined) requiring CPB between April 2015 and December 2021 at a large quaternary medical center. The primary outcome was postoperative lung function defined as the ratio of Pa o2 to fractional inspired oxygen concentration (F io2 ); P/F ratio 6 hours following surgery or before extubation. The association between CPB in-line sample monitor Pa o2 and primary, secondary, and exploratory outcomes was evaluated using linear or logistic regression models adjusting for available baseline confounders. RESULTS: A total of 9141 patients met inclusion and exclusion criteria, and 8429 (92.2%) patients had complete baseline variables available and were included in the analysis. The mean age of the sample was 64 (SD = 13), and 68% were men (n = 6208). The time-weighted average (TWA) of in-line sample monitor Pa o2 during CPB was weakly positively associated with the postoperative P/F ratio. With a 100-unit increase in Pa o2 , the estimated increase in postoperative P/F ratio was 4.61 (95% CI, 0.71-8.50; P = .02). Our secondary analysis showed no significant association between Pa o2 with peak lactate 6 hours post CPB (geometric mean ratio [GMR], 1.01; 98.3% CI, 0.98-1.03; P = .55), average lactate 6 hours post CPB (GMR, 1.00; 98.3% CI, 0.97-1.03; P = .93), or acute kidney injury by Kidney Disease Improving Global Outcomes (KDIGO) criteria (odds ratio, 0.91; 98.3% CI, 0.75-1.10; P = .23). CONCLUSIONS: Our investigation found no clinically significant association between Pa o2 during CPB and postoperative lung function. Similarly, there was no association between Pa o2 during CPB and lactate levels, postoperative renal function, or other exploratory outcomes.

Serratus anterior and pectoralis plane blocks for robotically assisted mitral valve repair: a randomised clinical trial.

BACKGROUND: Minimally invasive cardiac surgery provokes substantial pain and therefore analgesic consumption. The effect of fascial plane blocks on analgesic efficacy and overall patient satisfaction remains unclear. We therefore tested the primary hypothesis that fascial plane blocks improve overall benefit analgesia score (OBAS) during the initial 3 days after robotically assisted mitral valve repair. Secondarily, we tested the hypotheses that blocks reduce opioid consumption and improve respiratory mechanics. METHODS: Adults scheduled for robotically assisted mitral valve repairs were randomised to combined pectoralis II and serratus anterior plane blocks or to routine analgesia. The blocks were ultrasound-guided and used a mixture of plain and liposomal bupivacaine. OBAS was measured daily on postoperative Days 1-3 and were analysed with linear mixed effects modelling. Opioid consumption was assessed with a simple linear regression model and respiratory mechanics with a linear mixed model. RESULTS: As planned, we enrolled 194 patients, with 98 assigned to blocks and 96 to routine analgesic management. There was neither time-by-treatment interaction (P=0.67) nor treatment effect on total OBAS over postoperative Days 1-3 with a median difference of 0.08 (95% confidence interval [CI]: -0.50 to 0.67; P=0.69) and an estimated ratio of geometric means of 0.98 (95% CI: 0.85-1.13; P=0.75). There was no evidence of a treatment effect on cumulative opioid consumption or respiratory mechanics. Average pain scores on each postoperative day were similarly low in both groups. CONCLUSIONS: Serratus anterior and pectoralis plane blocks did not improve postoperative analgesia, cumulative opioid consumption, or respiratory mechanics during the initial 3 days after robotically assisted mitral valve repair. CLINICAL TRIAL REGISTRATION: NCT03743194.

Association of Conventional Ultrafiltration on Postoperative Pulmonary Complications.

BACKGROUND: Postoperative pulmonary complications increase mortality after cardiac surgery. Conventional ultrafiltration may reduce pulmonary complications by removing mediators of bypass-induced inflammation and countering hemodilution. We tested the primary hypothesis that conventional ultrafiltration reduces postoperative pulmonary complications, and secondarily, improves early pulmonary function assessed by the ratio of PaO2 to fractional inspired oxygen concentration. METHODS: This retrospective analysis compared the incidence of postoperative pulmonary complications in adult patients who underwent cardiac surgery, with and without the use of conventional ultrafiltration, by using logistic regression with adjustment for confounding variables. The primary outcome was a composite of reintubation, prolonged ventilation, pneumonia, or pleural effusion. Secondarily, we examined early postoperative lung function using a quantile regression model. We also explored whether red blood cell transfusion differed between groups. RESULTS: Of 8026 patients, 1043 (13%) received conventional ultrafiltration. After adjustment for confounding variables, the incidence of the composite primary outcome was higher in the conventional ultrafiltration group (12.1% vs 9.9%; P = .03), with an estimated odds ratio of 1.25 (95% CI, 1.02-1.53; P = .03). The median (quantiles) PaO2-to-fractional inspired oxygen concentration ratio was 373 (303-433) vs 368 (303-428), with the estimated adjusted difference in medians of 5 (95% CI, -5.9 to 16; P = .37). The estimated odds ratio of intraoperative transfusion was 1.38 (95% CI, 1.19-1.60; P < .0001) and for postoperative transfusion was 1.30 (95% CI, 1.14-1.49; P = .0001). CONCLUSIONS: Use of conventional ultrafiltration was not associated with a reduction in the composite of postoperative pulmonary complications or improved early pulmonary function. We found no evidence of benefit from use of conventional ultrafiltration during cardiac surgery.

Derivation and Validation of Clinical Phenotypes of the Cardiopulmonary Bypass-Induced Inflammatory Response.

BACKGROUND: Precision medicine aims to change treatment from a "one-size-fits-all" approach to customized therapies based on the individual patient. Applying a precision medicine approach to a heterogeneous condition, such as the cardiopulmonary bypass (CPB)-induced inflammatory response, first requires identification of homogeneous subgroups that correlate with biological markers and postoperative outcomes. As a first step, we derived clinical phenotypes of the CPB-induced inflammatory response by identifying patterns in perioperative clinical variables using machine learning and simulation tools. We then evaluated whether these phenotypes were associated with biological response variables and clinical outcomes. METHODS: This single-center, retrospective cohort study used Cleveland Clinic registry data from patients undergoing cardiac surgery with CPB from January 2010 to March 2020. Biomarker data from a subgroup of patients enrolled in a clinical trial were also included. Patients undergoing emergent surgery, off-pump surgery, transplantation, descending thoracoabdominal aortic surgery, and planned ventricular assist device placement were excluded. Preoperative and intraoperative variables of patient baseline characteristics (demographics, comorbidities, and laboratory data) and perioperative data (procedural data, CPB duration, and hemodynamics) were analyzed to derive clinical phenotypes using K-means-based consensus clustering analysis. Proportion of ambiguously clustered was used to assess cluster size and optimal cluster numbers. After clusters were formed, we summarized perioperative profiles, inflammatory biomarkers (eg, interleukin [IL]-6 and IL-8), kidney biomarkers (eg, urine neutrophil gelatinase-associated lipocalin [NGAL] and IL-18), and clinical outcomes (eg, mortality and hospital length of stay). Pairwise standardized difference was reported for all summarized variables. RESULTS: Of 36,865 eligible cardiac surgery cases, 25,613 met inclusion criteria. Cluster analysis derived 3 clinical phenotypes: α, ß, and γ. Phenotype α (n = 6157 [24%]) included older patients with more comorbidities, including heart and kidney failure. Phenotype ß (n = 10,572 [41%]) patients were younger and mostly male. Phenotype γ (n = 8884 [35%]) patients were 58% female and had lower body mass index (BMI). Phenotype α patients had worse outcomes, including longer hospital length of stay (mean = 9 days for α versus 6 for both ß [absolute standardized difference {ASD} = 1.15] and γ [ASD = 1.08]), more kidney failure, and higher mortality. Inflammatory biomarkers (IL-6 and IL-8) and kidney injury biomarkers (urine NGAL and IL-18) were higher with the α phenotype compared to ß and γ immediately after surgery. CONCLUSIONS: Deriving clinical phenotypes that correlate with response biomarkers and outcomes represents an initial step toward a precision medicine approach for the management of CPB-induced inflammatory response and lays the groundwork for future investigation, including an evaluation of the heterogeneity of treatment effect.

Double Valve Replacement in a Patient With Hunter Syndrome.

Hunter syndrome is a rare disorder in which affected patients have significant airway abnormalities (macroglossia, small mouth opening, and supraglottic narrowing) that complicate their management. Deposition of glycosaminoglycans in the heart leads to cardiomyopathy, and cardiac valve dysplasia that can lead to valvular stenosis or regurgitation or both, necessitating valve replacement. Management of patients with Hunter syndrome is complex and needs a multidisciplinary team approach. Mechanical valve replacement is a suitable treatment option.

Post-cardiopulmonary bypass longitudinal strain provides higher prognostic ability than baseline strain or change in strain.

Context: Global longitudinal strain (GLS) measured by speckle-tracking echocardiography demonstrates excellent prognostic ability in predicting major adverse cardiac events after cardiac surgery. However, the optimal timing of intraoperative GLS measurement that provides the best prognostic value is unclear. Aim: Our goal was to evaluate whether GLS measured prior to cardiopulmonary bypass (pre-CPB GLS), following CPB (post-CPB GLS), or change in GLS provides the strongest association with postoperative complications. Setting and Design: Post hoc analysis of prospectively collected data from a clinical trial (NCT01187329). 72 patients with aortic stenosis undergoing elective AVR ± coronary artery bypass grafting between January 2011 and August 2013. Material and Methods: Myocardial deformation analysis from standardized transesophageal echocardiographic examinations were performed after anesthetic induction and chest closure. We evaluated the association between pre-CPB GLS, post-CPB GLS, and change in GLS (percent change from pre-CPB baseline) with postoperative atrial fibrillation and hospitalization >7 days. The association of post-CPB GLS with duration of mechanical ventilation, N-terminal pro-BNP (NT-proBNP) and troponin T were also assessed. Statistical Analysis: Multivariable logistic regression. Results: Risk-adjusted odds (OR[97.5%CI] of prolonged hospitalization increased an estimated 27% (1.27[1.01 to 1.59];Padj =0.035) per 1% decrease in absolute post-CPB GLS. Mean[98.3%CI] NT-proBNP increased 98.4[20 to 177]pg/mL; Padj =0.008), per 1% decrease in post-CPB GLS. Pre-CPB GLS or change in GLS were not associated with any outcomes. Conclusions: Post-CPB GLS provides the best prognostic value in predicting postoperative outcomes. Measuring post-CPB GLS may improve risk stratification and assist in future study design and patient outcome research.

Incidence, Outcomes, and Risk Factors for Preincision Cardiac Arrest in Cardiac Surgery Patients.

BACKGROUND: We examined the incidence, postoperative outcomes, and patient-related factors associated with preincision cardiac arrest in patients undergoing cardiac surgery. METHODS: We retrospectively examined adult patients undergoing elective or urgent cardiac surgery at the Cleveland Clinic between 2008 and 2019. The incidence of preincision cardiac arrest, defined as arrest between induction of general anesthesia and surgical incision, was reported. In a secondary analysis, we assessed the association between preincision cardiac arrest and major postoperative outcomes. In a tertiary analysis, we used adjusted linear regression models to explore the association between preincision cardiac arrest and prespecified patient risk factors, including severe left main coronary artery stenosis, left ventricular ejection fraction, moderate/severe right ventricular dysfunction, low-flow low-gradient aortic stenosis, and moderate/severe pulmonary hypertension. RESULTS: Preincision cardiac arrests occurred in 75 of 41,238 (incidence of 0.18%; 95% CI, 0.17-0.26) patients who had elective or urgent cardiac surgery. Successful cardiopulmonary resuscitation with return of spontaneous circulation or bridge to cardiopulmonary bypass occurred in 74 of 75 (98.6%) patients. Patients who experienced preincision cardiac arrest had significantly higher in-hospital mortality than those who did not (11% vs 2%; odds ratio [OR] (95% CI), 4.14 (1.94-8.84); P < .001). They were also more likely to suffer postoperative respiratory failure (46% vs 13%; OR [95% CI], 3.94 [2.40-6.47]; P < .001), requirement for renal replacement therapy (11% vs 2%; OR [95% CI], 3.90 [1.82-8.35]; P < .001), neurologic deficit (7% vs 2%; OR [95% CI], 2.49 (1.00-6.21); P = .05), and longer median hospital stay (15 vs 8 days; hazard ratio (HR) [95% CI], 0.68 [0.55-0.85]; P < .001). Reduced left ventricular ejection fraction (per 5% decrease) (OR [95% CI], 1.13 [1.03-1.22]; P = .006) and moderate/severe pulmonary hypertension (OR [95% CI], 3.40 [1.95-5.90]; P < .001) were identified as independent risk factors for cardiac arrest. CONCLUSIONS: Cardiac arrest after anesthetic induction is rare in cardiac surgical patients in our investigation. Though most patients are rescued, morbidity and mortality remain higher. Reduced left ventricular ejection fraction and moderate/severe pulmonary hypertension are associated with greater risk for preincision cardiac arrest.

Predictors and associated clinical outcomes of low cardiac output syndrome following cardiac surgery: insights from the LEVO-CTS trial.

AIMS: High-risk cardiac surgery is commonly complicated by low cardiac output syndrome (LCOS), which is associated with high mortality. There are limited data derived from multi-centre studies with adjudicated endpoints describing factors associated with LCOS and its downstream clinical outcomes. METHODS AND RESULTS: The Levosimendan in Patients with Left Ventricular Systolic Dysfunction Undergoing Cardiac Surgery Requiring Cardiopulmonary Bypass (LEVO-CTS) trial evaluated prophylactic levosimendan vs. placebo in patients with a reduced ejection fraction undergoing coronary artery bypass grafting (CABG) and/or valve surgery. We conducted a pre-specified analysis on LCOS, which was characterized by a four-part definition. We constructed a multivariable logistical regression model to evaluate risk factors associated with LCOS and performed Cox proportional hazards modelling to determine the association of LCOS with 90-day mortality. A total of 186 (22%) of 849 patients in the LEVO-CTS trial developed LCOS. The factors most associated with a higher adjusted risk of LCOS were pre-operative ejection fraction [odds ratio (OR) 1.26; 95% confidence interval (CI): 1.08-1.46 per 5% decrease] and age (OR 1.13; 95% CI: 1.04-1.24 per 5-year increase), whereas isolated CABG surgery (OR 0.44, 95% CI: 0.31-0.64) and levosimendan use (OR 0.65; 95% CI: 0.46-0.92) were associated with a lower risk of LCOS. Patients with LCOS had worse outcomes, including renal replacement therapy at 30-day (10 vs. 1%) and 90-day mortality (16 vs. 3%, adjusted hazard ratio of 5.04, 95% CI: 2.66-9.55). CONCLUSION: Low cardiac output syndrome is associated with a high risk of post-operative mortality in high-risk cardiac surgery.

Left Ventricular Twist Mechanics Before and After Aortic Valve Replacement: A Feasibility Study and Exploratory Analysis.

Introduction. We examined whether intraoperative assessment of left ventricular (LV) twist mechanics is feasible with transesophageal echocardiography (TEE). We then explored whether twist mechanics were altered by hemodynamic conditions or patient comorbidities. Methods. In this sub-analysis of clinical trial data, transgastric short-axis echocardiographic images of the LV base and apex were collected in patients having aortic valve replacement (AVR) at baseline and end of surgery. Transvalvular gradients and LV systolic and diastolic function were assessed using two-dimensional (2D) and Doppler echocardiography. 2D speckle-tracking echocardiography was used for off-line analysis of LV twist, twisting rate, and untwisting rate. We examined the intraoperative change in twist mechanics before and after AVR. LV twist mechanics were also explored by diabetic status, need for coronary artery bypass grafting (CABG), and use of epinephrine/norepinephrine. Results. Of 40 patients, 16 patients had acceptable TEE images for off-line LV twist analysis. Baseline median [Q1, Q3] LV twist was 12 [7, 16]°, twisting rate was 72 [41, 97]°/sec, and untwisting rate was -91 [-154, -56]°/s. Median [Q1, Q3] change in LV twist at end of surgery was -2 [-5, 3]°, twisting rate was 7 [-33, 31]°/s, and untwisting rate was 0 [-11, 43]°/s. No difference was noted between diabetic and non-diabetic patients or AVR and AVR-CABG patients. Conclusion. LV twist was augmented in patients with aortic stenosis, though twist indices were not affected by reduced afterload, diabetes, or coronary artery disease. Intraoperative assessment of twist mechanics may provide unique information on LV systolic and diastolic function, though fewer than 50% of TEE examinations successfully assessed twist. Clinical Trial Registry. This work is a sub-analysis of a clinical trial, registered on ClinicalTrials.gov on August 19, 2010 (NCT01187329), Andra Duncan, Principal Investigator.

Procedure-Specific Relationships Between Postoperative Troponin T and a Composite of Mortality and Low Cardiac Output Syndrome: A Retrospective Cohort Analysis.

BACKGROUND: Myocardial injury after coronary artery bypass grafting (CABG) is defined as troponin concentrations >10 times 99th percentile upper reference limit (URL) according to the Fourth Universal Definition. However, troponin concentrations after non-CABG cardiac surgery which indicate greater-than-expected myocardial injury and increased risk for complications remain unclear. Our goal was to assess procedure-specific relationships between troponin T and a composite outcome of low cardiac output syndrome and in-hospital mortality in cardiac surgical patients. METHODS: Patients having cardiac surgery between January 2010 and December 2017 were categorized into 4 groups by procedure: (1) CABG; (2) mitral valve repair; (3) aortic valve repair/replacement (AVR); (4) mitral valve replacement (MVR) or CABG + valve surgeries. Exclusion criteria were elevated preoperative troponin T, preoperative kidney failure, circulatory arrest, or preoperative/planned mechanical circulatory support. Logistic regression was used to assess the association between troponin T and composite outcome, both overall and by procedure, including assessment of the interaction between procedure and troponin T on outcome. RESULTS: Among 10,253 patients, 37 (0.4%) died and 393 (3.8%) developed the primary outcome. Troponin T concentrations differed by procedure (P < .001). Compared to CABG, AVR had 0.53 (99.2% confidence interval [CI], 0.50-0.56; unadjusted P < .001) times lower troponin T concentrations, while MVR/CABG + valve were 1.54 (99.2% CI, 1.45-1.62, unadjusted P < .001) times higher. There were linear relationships between log2 troponin T concentration and log odds mortality/low cardiac output syndrome. The (unadjusted) relationships were parallel for various types of surgery (interaction P = .59), but at different levels of the outcome. CONCLUSIONS: The relative increase in odds for mortality/low cardiac output syndrome per a similar increase in troponin T concentrations did not differ among cardiac surgical procedures, but the absolute troponin T concentrations did. Troponin concentrations should thus be interpreted in context of surgical procedure.

Patient characteristics and surgical variables associated with intraoperative reduced right ventricular function.

OBJECTIVE: Perioperative right ventricular function is a significant predictor of patient outcomes after cardiac surgery. This prospective study aimed to identify perioperative factors associated with reduced intraoperative right ventricular function. METHODS: Right ventricular function was assessed at the beginning and end of surgery by standardized transesophageal echocardiographic measurements, including tricuspid annular plane systolic excursion, peak systolic longitudinal right ventricular strain, and fractional area change, in 109 adult patients undergoing cardiac surgery at Cleveland Clinic. Associations between right ventricular function and 33 patient characteristics and perioperative factors were analyzed by random forest machine learning. The relative importance of each variable in predicting right ventricular function at the end of surgery was determined. RESULTS: Longer aortic clamp duration and lower baseline right ventricular function were highly important variables for predicting worse right ventricular function measured by tricuspid annular plane systolic excursion, right ventricular strain, and fractional area change at the end of surgery. For example, right ventricular function after longer aortic clamp times of 100-120 minutes was worse (median [Q1, Q3] tricuspid annular plane systolic excursion 1.0 [0.9, 1.1] cm) compared with right ventricular function after shorter aortic clamp times of 50 to 70 minutes (tricuspid annular plane systolic excursion 1.5 [1.3, 1.7]; P = .001). Right ventricular strain at the end of surgery was reduced in patients with worse baseline right ventricular function compared with those with higher baseline right ventricular function (end of surgery right ventricular strain in lowest quartile -13.7 [-16.6, -12.4]% vs highest quartile -17.7 [-18.6, -15.3]% of baseline right ventricular function; P = .043). CONCLUSIONS: Intraoperative decline in right ventricular function is associated with longer aortic clamp time and worse baseline right ventricular function. Efforts to optimize these factors, including better myocardial protection strategies, may improve perioperative right ventricular function.

Risk factors, resource use, and cost of postoperative low cardiac output syndrome.

OBJECTIVE: Low cardiac output syndrome complicates recovery after cardiac surgery. We examined the incidence and risk factors for low cardiac output syndrome and its association with postoperative mortality, morbidity, resource use, and cost. METHODS: This cross-sectional retrospective observational study examined patients having cardiac surgery captured in the Premier Healthcare Database. Low cardiac output syndrome was defined as the requirement for postoperative mechanical circulatory support and/or hemodynamic instability requiring prolonged inotropic support. Incidence, risk factors, and association of low cardiac output syndrome with postoperative outcomes, including mortality, hospital and intensive care unit length of stay, hospital readmission, and cost at 30 days, 90 days, and 6 months, were examined. RESULTS: Among 59,810 patients from 164 hospitals having cardiac surgery between July 1, 2012, and June 30, 2014, low cardiac output syndrome developed in 6067 (10.1%) patients. Patients presenting in cardiogenic shock or systolic (± diastolic) heart failure were at greatest risk. Risk-adjusted in-hospital mortality was 12-fold greater with low cardiac output syndrome (odds ratio, 12.0; 95% confidence interval, 10.6-13.5). Risk-adjusted hospital costs (2019$; median [Q1, Q3]) were $64,041 [21,439] in patients who developed low cardiac output syndrome versus $48,086 [16,098] without; P < .001. Increased costs were driven by longer risk-adjusted hospital stay (10.1 [4.5] vs 8.5 [3.8] days); P < .001, intensive care unit (5.5 [2.5] vs 3.3 [1.5] days; P < .001) stay, and all-cause 30-day adjusted hospital readmission rates (mean [SD] 16.6 [8.2]% vs 13.9 [7.2]%; P < .001). CONCLUSIONS: Cardiac surgical patients who develop postoperative low cardiac output syndrome suffer greater mortality and have greater resource use, health care costs, and all-cause readmission, which informs perioperative decision making, and impacts hospital performance metrics and federal priority to reduce health care costs.

Effect of 6% Hydroxyethyl Starch 130/0.4 on Inflammatory Response and Pulmonary Function in Patients Having Cardiac Surgery: A Randomized Clinical Trial.

BACKGROUND: Cardiac surgery with cardiopulmonary bypass induces a profound inflammatory response that, when severe, can lead to multiorgan system dysfunction. Preliminary data suggest that administration of hydroxyethyl starch (HES) solutions may mitigate an inflammatory response and improve pulmonary function. Our goal was to examine the effect of 6% HES 130/0.4 versus 5% human albumin given for intravascular plasma volume replacement on the perioperative inflammatory response and pulmonary function in patients undergoing cardiac surgery. METHODS: This was a subinvestigation of a blinded, parallel-group, randomized clinical trial of patients undergoing elective aortic valve replacement surgery at the Cleveland Clinic main campus, titled "Effect of 6% Hydroxyethyl Starch 130/0.4 on Kidney and Haemostatic Function in Cardiac Surgical Patients." Of 141 patients who were randomized to receive either 6% HES 130/0.4 or 5% human albumin for intraoperative plasma volume replacement, 135 patients were included in the data analysis (HES n = 66, albumin n = 69). We assessed the cardiopulmonary bypass-induced inflammatory response end points by comparing the 2 groups' serum concentrations of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and macrophage migration inhibitory factor (MIF), measured at baseline and at 1 and 24 hours after surgery. We also compared the 2 groups' postoperative pulmonary function end points, including the ratio of partial pressure of arterial oxygen to fraction of inspired oxygen (Pao2:Fio2 ratio), dynamic lung compliance, oxygenation index (OI), and ventilation index (VI) at baseline, within 1 hour of arrival to the intensive care unit, and before tracheal extubation. The differences in the postoperative levels of inflammatory response and pulmonary function between the HES and albumin groups were assessed individually in linear mixed models. RESULTS: Serum concentrations of the inflammatory markers (TNF-α, IL-6, MIF) were not significantly different (P ≥ .05) between patients who received 6% HES 130/0.4 or 5% albumin, and there was no significant heterogeneity of the estimated treatment effect over time (P ≥ .15). The results of pulmonary function parameters (Pao2:Fio2 ratio, dynamic compliance, OI, VI) were not significantly different (P ≥ .05) between groups, and there was no significant heterogeneity of the estimated treatment effect over time (P ≥ .15). CONCLUSIONS: Our investigation found no significant difference in the concentrations of inflammatory markers and measures of pulmonary function between cardiac surgical patients who received 6% HES 130/0.4 versus 5% albumin.

Prognostic Utility of KDIGO Urine Output Criteria After Cardiac Surgery.

OBJECTIVES: Kidney Disease: Improving Global Outcomes (KDIGO) guidelines include assessment of creatinine and urine output to identify acute kidney injury (AKI). Whether urine output is an accurate indicator of AKI after cardiac surgery, however, is unclear. The authors' goal was to examine whether cardiac surgery patients who fulfilled criteria for AKI by KDIGO urine output criteria also demonstrated kidney injury by elevated creatinine, other kidney biomarkers, or had worse clinical outcomes. DESIGN: Secondary analysis of prospectively collected data from a clinical trial, "6% Hydroxyethyl starch 130/0.4 in Cardiac Surgery (NCT02192502)." SETTING: Academic, quaternary care hospital. PARTICIPANTS: Patients undergoing elective aortic valve replacement INTERVENTIONS: None MEASUREMENTS AND MAIN RESULTS: One hundred forty-one patients were classified into AKI stage by KDIGO urine output criteria within 24 hours after surgery. Kidney biomarkers (serum creatinine, urinary neutrophil gelatinase-associated lipocalin [NGAL], urinary interleukin-18 [IL-18]) and hospital and intensive care unit length of stay were analyzed across AKI stages. Urine output criteria classified four times as many patients with AKI than creatinine criteria (95 [67%] v 21 [15%]). Most patients meeting KDIGO urine output criteria for AKI postoperatively did not satisfy KDIGO creatinine criteria for AKI within one week (77 of 95 [81%]) or six-to-12 months (27 of 29 [93%]). Higher AKI stage assessed by urine output was not associated with higher NGAL, IL-18, or longer hospital or intensive care unit stays. CONCLUSIONS: Acute kidney injury classified by KDIGO urine output criteria was not associated with other biomarkers of kidney injury or worse patient outcomes. These data suggested that KDIGO urine output criteria after cardiac surgery may overclassify AKI stage; further research is needed.