Blood bupivacaine concentrations after pecto-serratus and serratus anterior plane injections of plain and liposomal bupivacaine in robotically-assisted mitral valve surgery: Sub-study of a randomized trial.

STUDY OBJECTIVE: To investigate the timing of peak blood concentrations and potential toxicity when using a combination of plain and liposomal bupivacaine for thoracic fascial plane blocks. DESIGN: Pharmacokinetic analysis. SETTING: Operating room. PATIENTS: Eighteen adult patients undergoing robotically-assisted mitral valve surgery. INTERVENTIONS: Ultrasound-guided pecto-serratus and serratus anterior plane blocks using a mixture of 0.5% bupivacaine HCl up to 2.5 mg/kg and liposomal bupivacaine up to 266 mg. MEASUREMENTS: Arterial plasma bupivacaine concentration. MAIN RESULTS: Samples from 13 participants were analyzed. There was substantial inter-patient variability in plasma concentrations. A geometric mean maximum bupivacaine concentration was 1492 ng/ml (range 660 to 4650 ng/ml) at median time of 30 min after injection. In 4/13 (31%) patients, plasma bupivacaine concentrations exceeded our predefined 2000 ng/ml toxic threshold. A second much smaller peak was observed about 32 h after the injection. No obvious signs of local anesthetic toxicity were observed. CONCLUSIONS: Combined injection of plain and liposomal bupivacaine for pecto-serratus/serratus anterior plane blocks produced a biphasic pattern, with the highest arterial plasma concentrations observed within 30 min. Maximum concentrations exceeded the potential toxic threshold in nearly a third of patients, but without clinical evidence of toxicity. Clinicians should not assume that routine combinations of plain and liposomal bupivacaine for thoracic fascial plane blocks are inherently safe.

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.

Evaluation and Management of Pulmonary Hypertension in Noncardiac Surgery: A Scientific Statement From the American Heart Association.

Pulmonary hypertension, defined as an elevation in blood pressure in the pulmonary arteries, is associated with an increased risk of death. The prevalence of pulmonary hypertension is increasing, with an aging population, a rising prevalence of heart and lung disease, and improved pulmonary hypertension survival with targeted therapies. Patients with pulmonary hypertension frequently require noncardiac surgery, although pulmonary hypertension is associated with excess perioperative morbidity and death. This scientific statement provides guidance on the evaluation and management of pulmonary hypertension in patients undergoing noncardiac surgery. We advocate for a multistep process focused on (1) classification of pulmonary hypertension group to define the underlying pathology; (2) preoperative risk assessment that will guide surgical decision-making; (3) pulmonary hypertension optimization before surgery to reduce perioperative risk; (4) intraoperative management of pulmonary hypertension to avoid right ventricular dysfunction and to maintain cardiac output; and (5) postoperative management of pulmonary hypertension to ensure recovery from surgery. Last, this scientific statement highlights the paucity of evidence to support perioperative pulmonary hypertension management and identifies areas of uncertainty and opportunities for future investigation.

A nomogram to predict postoperative pulmonary complications after cardiothoracic surgery.

OBJECTIVE: The objective was to develop a novel scoring system that would be predictive of postoperative pulmonary complications in critically ill patients after cardiac and major vascular surgery. METHODS: A total of 17,433 postoperative patients after coronary artery bypass graft, valve, or thoracic aorta repair surgery admitted to the cardiovascular intensive care units at Cleveland Clinic Main Campus from 2009 to 2015. The primary outcome was the composite of postoperative pulmonary complications, including pneumonia, prolonged postoperative mechanical ventilation (>48 hours), or reintubation occurring during the hospital stay. Elastic net logistic regression was used on the training subset to build a prediction model that included perioperative predictors. Five-fold cross-validation was used to select an appropriate subset of the predictors. The predictive efficacy was assessed with calibration and discrimination statistics. Post hoc, of 13,353 adult patients, we tested the clinical usefulness of our risk prediction model on 12,956 patients who underwent surgery from 2015 to 2019. RESULTS: Postoperative pulmonary complications were observed in 1669 patients (9.6%). A prediction model that included baseline and demographic risk factors along with perioperative predictors had a C-statistic of 0.87 (95% confidence interval, 0.86-0.88), with a corrected Brier score of 0.06. Our prediction model maintains satisfactory discrimination (C-statistics of 0.87) and calibration (Brier score of 0.07) abilities when evaluated on an independent dataset of 12,843 recent adult patients who underwent cardiovascular surgery. CONCLUSIONS: A novel prediction nomogram accurately predicted postoperative pulmonary complications after major cardiac and vascular surgery. Intensivists may use these predictors to allow for proactive and preventative interventions in this patient population.

An Expert Review of Chest Wall Fascial Plane Blocks for Cardiac Surgery.

The recent integration of regional anesthesia techniques into the cardiac surgical patient population has become a component of enhanced recovery after cardiac surgery pathways. Fascial planes of the chest wall enable single-injection or catheter-based infusions to spread local anesthetic over multiple levels of innervation. Although median sternotomy remains a common approach to cardiac surgery, minimally invasive techniques have integrated additional methods of performing cardiac surgery. Understanding the surgical approach and chest wall innervation is crucial to success in choosing the appropriate chest wall block. Parasternal intercostal plane techniques (previously termed "pectointercostal fascial plane" and "transversus thoracic muscle plane") provide anterior chest and ipsilateral sternal coverage. Anterolateral chest wall coverage is feasible with the interpectoral plane and pectoserratus plane blocks (previously termed "pectoralis") and superficial and deep serratus anterior plane blocks. The erector spinae plane block provides extensive coverage of the ipsilateral chest wall. Any of these techniques has the potential to provide bilateral chest wall analgesia. The relative novelty of these techniques requires ongoing research to be strategic, thoughtful, and focused on clinically meaningful outcomes to enable widespread evidence-based implementation. This review article discusses the key perspectives for performing and assessing chest wall blocks in a cardiac surgical population.

Effectiveness and Safety of E-aminocaproic Acid in Overall and Less-Invasive Cardiac Surgeries.

OBJECTIVES: To examine E-aminocaproic acid effectiveness in reducing transfusion requirements in overall and less-invasive cardiac surgery, and to assess its safety. DESIGN: Retrospective cohort study. SETTING: Single-center tertiary academic medical center. PARTICIPANTS: A total of 19,111 adult patients who underwent elective surgery requiring cardiopulmonary bypass from January 1, 2008, through December 31, 2016. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Propensity matching was used to create well-balanced groups and separately compare both overall cohort and less-invasive surgery with and without E-aminocaproic acid. Supplementary zero-inflated negative binomial regression analysis was used because outcome data were zero-inflated. Effectiveness was assessed by transfusion requirements, and safety by comparison of in-hospital outcomes. In the overall cohort, patients receiving E-aminocaproic acid received fewer red blood cells postoperatively and fewer intra- and postoperativel blood products. In a less-invasive cohort, there was no significant difference in red blood cell transfusion either intra- or postoperatively, but the E-aminocaproic group received fewer intra- and postoperative platelets, intraoperative cryoprecipitate, and postoperative plasma. There were no significant differences for in-hospital outcomes in both less-invasive and overall cohorts. CONCLUSIONS: The reduction of postoperative red blood cell requirement observed when analyzing the overall cohort did not translate to less-invasive cardiac surgery in the authors' patient population; however, both overall and less-invasive cohorts had lower requirements for other blood components with E-aminocaproic acid. There was no association with major Society of thoracic surgeons (STS)-defined morbidity and mortality in both groups.

Regional anesthesia for thoracic surgery: a narrative review of indications and clinical considerations.

Background and Objective: Surgical procedures involving incisions of the chest wall regularly pose challenges for intra- and postoperative analgesia. For many decades, opioids have been widely administered to target both, acute and subsequent chronic incisional pain. Opioids are potent and highly addictive drugs that can provide sufficient pain relief, but simultaneously cause unwanted effects ranging from nausea, vomiting and constipation to respiratory depression, sedation and even death. Multimodal analgesia consists of the administration of two or more medications or analgesia techniques that act by different mechanisms for providing analgesia. Thus, multimodal analgesia aims to improve pain relief while reducing opioid requirements and opioid-related side effects. Regional anesthesia techniques are an important component of this approach. Methods: For this narrative review, authors summarized currently used regional anesthesia techniques and performed an extensive literature search to summarize specific current evidence. For this, related articles from January 1985 to March 2022 were taken from PubMed, Web of Science, Embase and Cochrane Library databases. Terms such as "pectoral nerve blocks", "serratus plane block", "erector spinae plane block" belonging to blocks used in thoracic surgery were searched in different combinations. Key Content and Findings: Potential advantages of regional anesthesia as part of multimodal analgesia regiments are reduced surgical stress response, improved analgesia, reduced opioid consumption, reduced risk of postoperative nausea and vomiting, and early mobilization. Potential disadvantages include the possibility of bleeding related to regional anesthesia procedure (particularly epidural hematoma), dural puncture with subsequent dural headache, systemic hypotension, urine retention, allergic reactions, local anesthetic toxicity, injuries to organs including pneumothorax, and a relatively high failure especially with continuous techniques. Conclusions: This narrative review summarizes regional anesthetic techniques, specific indications, and clinical considerations for patients undergoing thoracic surgery, with evidence from studies performed. However, there is a need for more studies comparing new block methods with standard methods so that clinical applications can increase patient satisfaction.

Bilateral continuous posterior quadratus lumborum block for analgesia after open abdominal surgery: A prospective case series.

The quadratus lumborum (QL) block provides analgesia to the abdominal wall while sparing the side effects of neuraxial blocks. We describe a case series of eight patients treated with a continuous infusion of local anesthetic via bilateral posterior QL catheters infusion block for analgesia after abdominal surgeries. We found that the median duration of the procedure was 26 min and the median opioid consumption over the first postoperative 72 h was 110 mg of morphine equivalents. The bilateral continuous posterior QL block is a feasible analgesic intervention and can be considered as a component of multimodal analgesic pathways.

Regional Anesthesia in Cardiac Surgery: An Overview of Fascial Plane Chest Wall Blocks.

Optimal analgesia is an integral part of enhanced recovery after surgery (ERAS) programs designed to improve patients' perioperative experience and outcomes. Regional anesthetic techniques in a form of various fascial plane chest wall blocks are an important adjunct to the optimal postoperative analgesia in cardiac surgery. The most common application of fascial plane chest wall blocks has been for minimally invasive cardiac surgical procedures. An abundance of case reports has been described in the anesthesia literature and reports appear promising, yet higher-level safety and efficacy evidence is lacking. Those providing anesthesia for minimally invasive cardiac procedures should become familiar with fascial plane anatomy and block techniques to be able to provide enhanced postsurgical analgesia and facilitate faster functional recovery and earlier discharge. The purpose of this review is to provide an overview of contemporary fascial plane chest wall blocks used for analgesia in cardiothoracic surgery. Specifically, we focus on relevant anatomic considerations and technical descriptions including pectoralis I and II, serratus anterior, pectointercostal fascial, transverse thoracic muscle, and erector spine plane blocks. In addition, we provide a summary of reported local anesthetic doses used for these blocks and a current state of the literature investigating their efficacy, duration, and comparisons with standard practices. Finally, we hope to stimulate further research with a focus on delineating mechanisms of action of novel emerging blocks, appropriate dosing regimens, and subsequent analysis of their effect on patient outcomes.

Predicting Right Ventricular Failure After LVAD Implantation: Role of Tricuspid Valve Annulus Displacement.

OBJECTIVES: Right ventricular failure after left ventricular assist device implantation increases postoperative morbidity and mortality. Whether intraoperative echocardiographic and hemodynamic measurements predict right ventricular failure is unclear. Speckle-tracking-derived tricuspid annulus displacement may provide a useful, effective, and straightforward predictor of severe right ventricular failure in patients having left ventricular device implantation. The aim of this study was to determine if intraoperative tricuspid annulus displacement is a stronger discriminator compared with the global longitudinal strain and modified tricuspid annular plane systolic excursion, the Michigan risk score, and pulmonary artery pulsatility index. DESIGN: Retrospective analysis. SETTING: A tertiary-care referral center. PARTICIPANTS: Patients scheduled for left ventricular assist device implantation from January 2010 to December 2017. INTERVENTIONS: None MEASUREMENTS AND MAIN RESULTS: The authors examined 86 patients undergoing left ventricular assist device implantation with adequate intraoperative echocardiographic images. The analyses did not demonstrate an association between tricuspid annulus displacement and severe right ventricular failure (univariate C-statistics <0.60 for all 4 echocardiographic measures). The discrimination ability was not significantly better than strain (DeLong test p = 0.44) and modified tricuspid annular plane systolic excursion (p = 0.89). The discrimination ability of tricuspid annulus displacement measurements was not better than the Michigan risk score (p = 0.65) and pulmonary artery pulsatility index (p = 0.73). CONCLUSIONS: Intraoperative echocardiographic parameters, including tricuspid annulus displacement, modified tricuspid annular plane systolic excursion, and strain, are poor discriminators of severe right ventricular failure after left ventricular assist device implantation. The preoperative Michigan risk-scoring system and intraoperative pulmonary artery pulsatility index are equally unreliable.

Fascial plane blocks in thoracic surgery: a new era or plain painful?

PURPOSE OF REVIEW: The demand for well-tolerated, effective, and opioid reducing pain management has become imperative in thoracic surgery. With the recent movement away from neuraxial analgesia for thoracic surgical patients, great interest in alternative analgesic techniques of the chest wall has developed. Multiple fascial plane blocks have been developed for pain management of the lateral chest wall and we present an up-to-date review of these popular new interventions. RECENT FINDINGS: The pectoralis and serratus anterior plane blocks may offer effective analgesia of the lateral chest wall for thoracic surgical patients. The erector spinae plane block may offer more extensive analgesic coverage but requires further investigation. SUMMARY: Fascial plane blocks hold the potential for well-tolerated and effective analgesia for thoracic surgical patients as part of a multimodal regimen of pain relief. However, many questions remain regarding block characteristics. As the literature matures, more formal recommendations will be made but quality trials are needed to provide this guidance.

Extracorporeal Membrane Oxygenation in Pulmonary Endarterectomy Patients.

OBJECTIVES: To investigate short-term outcomes in patients with chronic thromboembolic pulmonary hypertension (CTEPH) presenting for pulmonary endarterectomy (PEA) and requiring extracorporeal membrane oxygenation (ECMO) during the perioperative period. DESIGN: Retrospective observational case series involving patients who underwent PEA for CTEPH, with focus on a subpopulation requiring perioperative ECMO support. SETTING: Single academic tertiary center. PARTICIPANTS: Patients who underwent PEA for CTEPH between January 1997 and December 2015 and required ECMO support. INTERVENTIONS: PEA for CTEPH with ECMO support at any time during the perioperative period. MEASUREMENTS AND MAIN RESULTS: A total of 150 patients underwent PEA for CEPTH during the study period. Of the 150 patients, 14 (9.3%) required ECMO support and (43%) survived, were discharged, and were alive at the time of the review. A total of 8 (57%) ECMO patients died during hospitalization. Although indications and type of support changed in some patients during their hospital course, the majority of patients required venovenous ECMO support for hypoxia (N = 9) versus venoarterial ECMO for hemodynamic support (N = 5) as initial indication. The mean length of stay among survivors was 42.2 ± 22 days. Severe RV dysfunction was present preoperatively among 6 patients in the nonsurvivors group (75%) and 2 in the survivors group (33%). The overall mean duration of ECMO support was 7.3 ± 5.3 days (8.3 ± 7.3 days among survivors and 6.5 ± 3.5 days among nonsurvivors). Four patients died while on ECMO. CONCLUSIONS: Although still associated with high morbidity and mortality, ECMO appears to be an important treatment adjunct providing additional time for healing and recovery of cardiopulmonary function in patients who develop severe hypoxemia or right ventricular failure after PEA.

Patients at High Risk for Obstructive Sleep Apnea Are at Increased Risk for Atrial Fibrillation After Cardiac Surgery: A Cohort Analysis.

BACKGROUND: Patients with obstructive sleep apnea (OSA) experience intermittent hypoxia, hypercarbia, and sympathetic activation during sleep, which increases risk for paroxysmal atrial fibrillation and other cardiac arrhythmias. Whether patients with OSA experience increased episodes of atrial fibrillation after cardiac surgery is unclear. We examined whether patients at increased risk for OSA, assessed by the STOP-BANG (snoring, tired during the day, observed stop breathing during sleep, high blood pressure, body mass index more than 35 kg/m, age more than 50 years, neck circumference more than 40 cm, and male gender) questionnaire, had a higher incidence of new-onset postoperative atrial fibrillation after cardiac surgery. Because both postoperative atrial fibrillation and OSA increase resource utilization, we secondarily examined whether patients at increased OSA risk had longer duration of postoperative mechanical ventilation and intensive care unit (ICU) length of stay. METHODS: With institutional review board approval, this retrospective observational study evaluated adult patients who underwent elective cardiac surgery requiring cardiopulmonary bypass between 2014 and 2015 with preoperative assessment of OSA risk using the STOP-BANG questionnaire. Patients with a history of atrial fibrillation were excluded. The association between the STOP-BANG score and postoperative atrial fibrillation was examined using a multivariable logistic regression model. Secondarily, we estimated the association between the STOP-BANG score and duration of initial intubation using multivariable linear regression and ICU length of stay using Cox proportional hazards regression. We also descriptively summarized the percentage of patients requiring tracheal reintubation for mechanical ventilation. RESULTS: Of 4228 cardiac surgery patients, 1593 met inclusion and exclusion criteria. An increased STOP-BANG score was associated with higher odds of postoperative atrial fibrillation (odds ratio [95% confidence interval {CI}], 1.16 [1.09-1.23] per-point increase in the STOP-BANG score; P < .001). The STOP-BANG score was not associated with ICU length of stay (estimated hazard ratio [97.5% CI], 0.99 [0.96-1.03] per-point increase in the STOP-BANG score; P = .99) or duration of initial intubation (ratio of geometric means [97.5% CI], 1.01 [1.00-1.04]; P = .03; significance criterion [Bonferroni correction] < 0.025). One percent of patients required reintubation. DISCUSSION: Increasing risk for OSA, assessed by STOP-BANG, was associated with higher odds of postoperative atrial fibrillation, but not prolonged duration of mechanical ventilation or ICU length of stay.