Effect of Regional Analgesia Techniques on Opioid Consumption and Length of Stay After Thoracic Surgery.

BACKGROUND: We examined how intercostal nerve block (ICNB) with standard bupivacaine and ICNB with extended-release liposomal bupivacaine, compared with thoracic epidural analgesia (TEA), were associated with postoperative opioid pain medication consumption and hospital length of stay (LOS) after thoracic surgery. METHODS: We studied 1935 patients who underwent thoracic surgery between January 1, 2010, and November 30, 2017, at a tertiary academic center. Primary and secondary outcomes were postoperative opioid consumption expressed as morphine milligram equivalents (MMEs) at 24, 48, and 72 hours after surgery, the LOS, and total MME consumption from surgery to discharge. RESULTS: Of these patients, 888 (45.9%) received TEA, 730 (37.7%) ICNB with standard bupivacaine, 127 (6.6%) ICNB with liposomal bupivacaine, and 190 (9.8%) no regional analgesia. Compared with epidural analgesia, in 2017, ICNB liposomal bupivacaine provided similar pain control in terms of MME consumption at 24 and 72 hours, but decreased MME consumption at 48 hours (odds ratio [OR] = 0.33; confidence interval [CI] = 0.14-0.81) and at discharge (OR = 0.28; CI = 0.12-0.68) and was associated with a higher likelihood for a shorter LOS (hazard ratio = 3.46; CI = 2.42-4.96). Compared with TEA, ICNB with standard bupivacaine and no regional analgesia use showed varying impact on MME consumption between 24 and 72 hours after surgery, and their use was not associated with a significantly reduced MME consumption at discharge but with a shorter hospital LOS. CONCLUSIONS: Multimodal analgesia involving regional anesthetic alternatives to TEA could help manage postoperative pain in thoracic surgery patients.

Mean platelet volume and cardiac-surgery-associated acute kidney injury: a retrospective study.

PURPOSE: Increased mean platelet volume (MPV) may indicate platelet activation, platelet aggregation, and a resulting prothrombotic state. Such changes in the postoperative period have been associated with organ injury and adverse outcomes. We hypothesized that changes in MPV after cardiac surgery are associated with both a higher risk of acute kidney injury (AKI) and mortality. METHODS: In this retrospective study, we evaluated consecutive patients undergoing adult cardiac surgery patients between 12 December 2011 and 5 June 2018. The change in MPV was derived by calculating the difference between the baseline MPV before surgery and the average postoperative MPV just prior to the occurrence of AKI. We defined postoperative AKI according to Kidney Disease: Improving Global Outcomes Clinical Practice Guideline for Acute Kidney Injury as either a ≥ 50% increase in serum creatinine in the first ten postoperative days, or an increase of ≥ 0.3 mg·dL-1 during any 48-hr window across the ten-day postoperative period. Multivariable logistic regression analysis was used to examine the association between MPV change and postoperative AKI and mortality. RESULTS: Of the 4,204 patients studied, 1,373 (32.7%) developed postoperative AKI, including 83 (2.0%) and 38 (0.9%) who developed stages II and III AKI, respectively. Compared with patients who had an increase in median postoperative MPV of 0.2 femtolitre (fL), those with an increase of 0.8 fL had an 80% increase in the odds of developing AKI (adjusted odds ratio [aOR], 1.80; 95% confidence interval [CI],1.36 to 2.38; P < 0.001) and were almost twice as likely to progress to a higher severity AKI (aOR, 1.66; 95% CI, 1.28 to 2.16; P < 0.001). Change in MPV was not associated with mortality (aOR,1.32; 95% CI, 0.92 to 1.89; P = 0.14). CONCLUSION: Increased MPV change in the postoperative period was associated with both increased risk and severity of AKI, but not mortality.

RéSUMé: OBJECTIF: Un volume plaquettaire moyen (VPM) augmenté peut être indicatif d'une activation plaquettaire, d'une agrégation plaquettaire, et de l'état prothrombotique qui en résulte. De tels changements en période postopératoire ont été associés à des lésions aux organes et à des devenirs défavorables. Nous avons émis l'hypothèse que des changements du VPM après une chirurgie cardiaque seraient associés à un risque plus élevé d'insuffisance rénale aiguë et de mortalité. MéTHODE: Dans cette étude rétrospective, nous avons évalué des patients adultes consécutifs subissant une chirurgie cardiaque entre le 12 décembre 2011 et le 5 juin 2018. Le changement de VPM a été dérivé en calculant la différence entre le VPM de base avant la chirurgie et le VPM postopératoire moyen juste avant la survenue de l'IRA. Nous avons défini une IRA postopératoire sur la base des Directives Kidney Disease: Improving Global Outcomes Clinical Practice Guideline for Acute Kidney Injury (Les maladies rénales: Guide d'exercice clinique pour améliorer les devenirs globaux pour l'insuffisance rénale aiguë) en tant qu'une augmentation ≥ 50 % de la créatine sérique au cours des dix premiers jours postopératoires, ou une augmentation de ≥ 0,3 mg·dL−1 pendant toute fenêtre de 48 h au cours des dix premiers jours postopératoires. Une analyse multivariée de régression logistique a été utilisée pour examiner l'association entre le changement de VPM et l'IRA postopératoire et la mortalité. RéSULTATS: Parmi les 4204 patients à l'étude, 1373 (32,7 %) ont souffert d'IRA postopératoire, y compris 83 (2,0 %) et 38 (0,9 %) qui ont développé des IRA de stade II et III, respectivement. Par rapport aux patients ayant manifesté une augmentation du VPM postopératoire médian de 0,2 femtolitre (fL), ceux affichant une augmentation de 0,8 fL ont démontré une augmentation de 80 % de la probabilité d'IRA (rapport de cotes ajusté [RCA], 1,80; intervalle de confiance [IC] 95 %, 1,36 à 2,38; P < 0,001) et couraient un risque pratiquement deux fois plus élevé de voir leur IRA progresser à un stade plus grave (RCA, 1,66; IC 95 %, 1,28 à 2,16; P < 0,001). Les changements de VPM n'étaient pas associés à la mortalité (RCA, 1,32; IC 95 %, 0,92 à 1,89; P = 0,14). CONCLUSION: Une augmentation accrue du VPM en période postopératoire a été associée à un risque et une gravité accrus d'IRA, mais pas à la mortalité.

CYP2D6 Genotype-guided Metoprolol Therapy in Cardiac Surgery Patients: Rationale and Design of the Pharmacogenetic-guided Metoprolol Management for Postoperative Atrial Fibrillation in Cardiac Surgery (PREEMPTIVE) Pilot Study.

OBJECTIVES: The Preemptive Pharmacogenetic-guided Metoprolol Management for Atrial Fibrillation in Cardiac Surgery (PREEMPTIVE) pilot trial aims to use existing institutional resources to develop a process for integrating CYP2D6 pharmacogenetic test results into the patient electronic health record, to develop an evidence-based clinical decision support tool to facilitate CYP2D6 genotype-guided metoprolol administration in the cardiac surgery setting, and to determine the impact of implementing this CYP2D6 genotype-guided integrated approach on the incidence of postoperative atrial fibrillation (AF), provider, and cost outcomes. DESIGN: One-arm Bayesian adaptive design clinical trial. SETTING: Single center, university hospital. PARTICIPANTS: The authors will screen (including CYP2D6 genotype) up to 600 (264 ± 144 expected under the adaptive design) cardiac surgery patients, and enroll up to 200 (88 ± 48 expected) poor, intermediate, and ultrarapid CYP2D6 metabolizers over a period of 2 years at a tertiary academic center. INTERVENTIONS: All consented and enrolled patients will receive the intervention of CYP2D6 genotype-guided metoprolol management based on CYP2D6 phenotype classified as a poor, intermediate, extensive (normal), or ultrarapid metabolizer. MEASUREMENTS AND MAIN RESULTS: The primary outcome will be the incidence of postoperative AF. Secondary outcomes relating to rates of CYP2D6 genotype-guided prescription changes, costs, lengths of stay, and implementation metrics also will be investigated. CONCLUSIONS: The PREEMPTIVE pilot study is the first perioperative pilot trial to provide essential information for the design of a future, large-scale trial comparing CYP2D6 genotype-guided metoprolol management with a nontailored strategy in terms of managing AF. In addition, secondary outcomes regarding implementation, clinical benefit, safety, and cost-effectiveness in patients undergoing cardiac surgery will be examined.

Future Technology.

Mitral regurgitation is the most common valvular disease and significant (moderate/severe) mitral regurgitation is found in 2.3% of the population older than 65 years. New transcatheter minimally invasive technologies are being developed to address mitral valve disease in patients deemed too high a risk for conventional open-heart surgery. There are several features of the mitral valve (saddle-shaped noncalcified annulus with irregular leaflet geometry) that make a transcatheter approach to repair or replacing the valve more challenging compared with the aortic valve. Several devices are under investigation for transcatheter mitral valve replacement, and also for mitral valve repair targeting the mitral valve leaflets, chordae tendinae, and mitral annulus. The MitraClip device is the only Food and Drug Administration-approved device to treat mitral regurgitation by targeting the mitral leaflets. There are eight minimally invasive devices being studied in humans that target the mitral annulus, and at least two devices being studied in animal models. There are 5 devices in clinical trials for minimally invasive approaches targeting the chordae tendinae. More than 10 different transcatheter mitral valves are in various stages of development and clinical trials. These transcatheter mitral valves can be delivered either through a transseptal, transapical, transaortic, or left atriotomy approach. It seems likely that transcatheter treatment approaches to mitral valve disease will become more common, at least in the sick and elderly patient population.

Feasibility of left atrial appendage device closure following chronically failed surgical ligation.

BACKGROUND: Incomplete surgical left atrial appendage occlusion (S-LAAO) with a narrow neck has been shown to predict an increased rate of embolic stroke. Patients with a previously attempted S-LAAO were systematically excluded from all clinical trials of LAA closure devices. OBJECTIVE: The purpose of this study was to evaluate the feasibility of Watchman LAA device closure for patients referred with chronically incomplete S-LAAO. METHODS: A prospective single-arm feasibility cohort evaluated only subjects undergoing Watchman LAA closure following incomplete S-LAAO. Patients referred and implanted were followed in the Vanderbilt LAA Registry. Preprocedure computed tomographic angiography and transesophageal echocardiography (TEE) were performed to evaluate suitability for closure, with 45-day follow-up TEE postimplant. RESULTS: All attempted LAA closures after incomplete S-LAAO were successful (n = 6). Mean age was 76.3 ± 7 years. Mean CHADS2Vasc score was 3.8 ± 0.8, and HAS-BLED score was 3.5 ± 0.5. At 45-day follow up, all subjects had complete device seal with no thrombus on device and had transitioned to clopidogrel plus aspirin. Three subjects had narrow ostial necks with a maximum diameter ≤9 mm. In all cases, the 4.7-mm Watchman access sheath was able to cross the ostial stricture. Mean occluder size implanted was 28 ± 4 mm. Mean LAA dimension by TEE in the 45° and 135° views for depth was 31 mm and ostial diameter was 11 × 16 mm, below the minimum Watchman indication for use of 17 mm. No major intraoperative complications occurred. CONCLUSION: Watchman LAA closure seems to be feasible in patients with chronically incomplete S-LAAO, including subjects with a narrow neck ≤9 mm in width.

Fish Oil and Perioperative Bleeding.

Background Fish oil is among the most common natural supplements for treatment of hypertriglyceridemia or prevention of cardiovascular disease. However, concerns about theoretical bleeding risk have led to recommendations that patients should stop taking fish oil before surgery or delay in elective procedures for patients taking fish oil by some health care professionals. Methods and Results We tested the effect of fish oil supplementation on perioperative bleeding in a multinational, placebo-controlled trial involving 1516 patients who were randomized to perioperative fish oil (eicosapentaenoic acid+docosahexaenoic acid; 8-10 g for 2-5 days preoperatively, and then 2 g/d postoperatively) or placebo. Primary outcome was major perioperative bleeding as defined by the Bleeding Academic Research Consortium. Secondary outcomes include perioperative bleeding per thrombolysis in myocardial infarction and International Society on Thrombosis and Hemostasis definitions, chest tube output, and total units of blood transfused. Participants' mean (SD) age was 63 (13) years, and planned surgery included coronary artery bypass graft (52%) and valve surgery (50%). The primary outcome occurred in 92 patients (6.1%). Compared with placebo, risk of Bleeding Academic Research Consortium bleeding was not higher in the fish oil group: odds ratio, 0.81; 95% CI, 0.53-1.24; absolute risk difference, 1.1% lower (95% CI, -3.0% to 1.8%). Similar findings were seen for secondary bleeding definitions. The total units of blood transfused were significantly lower in the fish oil group compared with placebo (mean, 1.61 versus 1.92; P<0.001). Evaluating achieved plasma phospholipid omega-3 polyunsaturated fatty acids levels with supplementation (on the morning of surgery), higher levels were associated with lower risk of Bleeding Academic Research Consortium bleeding, with substantially lower risk in the third (odds ratio, 0.30 [95% CI, 0.11-0.78]) and fourth (0.36 [95% CI, 0.15-0.87]) quartiles, compared with the lowest quartile. Conclusions Fish oil supplementation did not increase perioperative bleeding and reduced the number of blood transfusions. Higher achieved n-3-PUFA levels were associated with lower risk of bleeding. These novel findings support the need for reconsideration of current recommendations to stop fish oil or delay procedures before cardiac surgery. Clinical Trial Registration URL: https://www.clinicaltrials.gov . Unique identifier: NCT00970489.

Point-of-Care Ultrasound Facilitated Detection of Femoral Occlusive Septic Emboli During Mitral Valve Surgery: A Case Report.

Acute lower extremity ischemia from septic emboli is a surgical emergency. Timely diagnosis and management are critical to improve patient outcome. However, traditional diagnostic modalities such as intraoperative angiogram are time-consuming, require special equipment and personnel, and introduce contrast exposure for critically ill patients. There are limited reports of utilization of point-of-care ultrasound to detect peripheral septic emboli. We present a case where femoral occlusive septic emboli were identified by point-of-care ultrasound after mitral valve replacement. This facilitated early surgical embolectomy and limb salvage. We suggest that perioperative point-of-care ultrasonography should be used as a first-line screening test in patients with acute lower extremity ischemia.

The Risk of Oxygen during Cardiac Surgery (ROCS) trial: study protocol for a randomized clinical trial.

BACKGROUND: Anesthesiologists administer excess supplemental oxygen (hyper-oxygenation) to patients during surgery to avoid hypoxia. Hyper-oxygenation, however, may increase the generation of reactive oxygen species and cause oxidative damage. In cardiac surgery, increased oxidative damage has been associated with postoperative kidney and brain injury. We hypothesize that maintenance of normoxia during cardiac surgery (physiologic oxygenation) decreases kidney injury and oxidative damage compared to hyper-oxygenation. METHODS/DESIGN: The Risk of Oxygen during Cardiac Surgery (ROCS) trial will randomly assign 200 cardiac surgery patients to receive physiologic oxygenation, defined as the lowest fraction of inspired oxygen (FIO2) necessary to maintain an arterial hemoglobin saturation of 95 to 97%, or hyper-oxygenation (FIO2 = 1.0) during surgery. The primary clinical endpoint is serum creatinine change from baseline to postoperative day 2, and the primary mechanism endpoint is change in plasma concentrations of F2-isoprostanes and isofurans. Secondary endpoints include superoxide production, clinical delirium, myocardial injury, and length of stay. An endothelial function substudy will examine the effects of oxygen treatment and oxidative stress on endothelial function, measured using flow mediated dilation, peripheral arterial tonometry, and wire tension myography of epicardial fat arterioles. DISCUSSION: The ROCS trial will test the hypothesis that intraoperative physiologic oxygenation decreases oxidative damage and organ injury compared to hyper-oxygenation in patients undergoing cardiac surgery. TRIAL REGISTRATION: ClinicalTrials.gov, ID: NCT02361944 . Registered on the 30th of January 2015.

Intraoperative cerebral oxygenation, oxidative injury, and delirium following cardiac surgery.

BACKGROUND: Delirium affects 20-30% of patients after cardiac surgery and is associated with increased mortality and persistent cognitive decline. Hyperoxic reperfusion of ischemic tissues increases oxidative injury, but oxygen administration remains high during cardiac surgery. We tested the hypothesis that intraoperative hyperoxic cerebral reperfusion is associated with increased postoperative delirium and that oxidative injury mediates this association. METHODS: We prospectively measured cerebral oxygenation with bilateral oximetry monitors in 310 cardiac surgery patients, quantified intraoperative hyperoxic cerebral reperfusion by measuring the magnitude of cerebral oxygenation above baseline after any ischemic event, and assessed patients for delirium twice daily in the ICU following surgery using the confusion assessment method for ICU (CAM-ICU). We examined the association between hyperoxic cerebral reperfusion and postoperative delirium, adjusted for the extent of cerebral hypoxia, the extent of cerebral hyperoxia prior to any ischemia, and additional potential confounders and risk factors for delirium. To assess oxidative injury mediation, we examined the association between hyperoxic cerebral reperfusion and delirium after further adjusting for plasma levels of F2-isoprostanes and isofurans at baseline and ICU admission, the association between hyperoxic cerebral reperfusion and these markers of oxidative injury, and the association between these markers and delirium. RESULTS: Ninety of the 310 patients developed delirium following surgery. Every 10%·hour of intraoperative hyperoxic cerebral reperfusion was independently associated with a 65% increase in the odds of delirium (OR, 1.65 [95% CI, 1.12-2.44]; P=0.01). Hyperoxia prior to ischemia was also independently associated with delirium (1.10 [1.01-1.19]; P=0.02), but hypoxia was not (1.12 [0.97-1.29]; P=0.11). Increased hyperoxic cerebral reperfusion was associated with increased concentrations of F2-isoprostanes and isofurans at ICU admission, increased concentrations of these markers were associated with increased delirium, and the association between hyperoxic cerebral reperfusion and delirium was weaker after adjusting for these markers of oxidative injury. CONCLUSIONS: Intraoperative hyperoxic cerebral reperfusion was associated with increased postoperative delirium, and increased oxidative injury following hyperoxic cerebral reperfusion may partially mediate this association. Further research is needed to assess the potential deleterious role of cerebral hyper-oxygenation during surgery.

Simultaneous comparisons of treatments at multiple time points: Combined marginal models versus joint modeling.

We discuss several aspects of multiple inference in longitudinal settings, focusing on many-to-one and all-pairwise comparisons of (a) treatment groups simultaneously at several points in time, or (b) time points simultaneously for several treatments. We assume a continuous endpoint that is measured repeatedly over time and contrast two basic modeling strategies: fitting a joint model across all occasions (with random effects and/or some residual covariance structure to account for heteroscedasticity and serial dependence), and a novel approach combining a set of simple marginal, i.e. occasion-specific models. Upon parameter and covariance estimation with either modeling approach, we employ a variant of multiple contrast tests that acknowledges correlation between time points and test statistics. This method provides simultaneous confidence intervals and adjusted p-values for elementary hypotheses as well as a global test decision. We compare via simulation the powers of multiple contrast tests based on a joint model and multiple marginal models, respectively, and quantify the benefit of incorporating longitudinal correlation, i.e. the advantage over Bonferroni. Practical application is illustrated with data from a clinical trial on bradykinin receptor antagonism.

Angiotensin converting enzyme inhibition increases ADMA concentration in patients on maintenance hemodialysis--a randomized cross-over study.

BACKGROUND: Endothelial dysfunction occurs in patients with end-stage renal disease (ESRD) and is associated with increased cardiovascular morbidity and mortality. Asymmetric dimethylarginine (ADMA) contributes to endothelial dysfunction in ESRD. In the general population, angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) decrease ADMA levels, but no study has compared the effect of these drugs in patients with ESRD on maintenance hemodialysis (MHD). METHODS: We evaluated the effect of 1-week treatment with ramipril (5 mg/d), valsartan (160 mg/d), and placebo on ADMA levels in 15 patients on MHD in a double-blind, placebo-controlled, three x three cross-over study. RESULTS: We found that ADMA levels were increased at baseline and throughout the dialysis session during ramipril treatment (p < 0.001 compared to both, placebo and valsartan). Ramipril did not increase ADMA levels in a study of patients without ESRD, suggesting that factors related to ESRD or hemodialysis contribute to the ACE inhibitor-induced increase in ADMA. We have previously shown that ACE inhibition increases bradykinin (BK) levels during hemodialysis. We therefore evaluated the effect of bradykinin on ADMA production in A549 cells; a cell line that expresses BK receptors. Incubation with BK increased intracellular ADMA concentration through BK B2-receptor stimulation. CONCLUSION: These data indicate that short-term ACE inhibition increases ADMA in patients on MHD whereas ARBs do not. In vitro studies further suggest that this may occur through BK-mediated increase in ADMA production during ACE inhibition. TRIAL REGISTRATION: Clinicaltrials.gov NCT00732069 August 6 2008 and NCT00607672 February 4 2008.

Perioperative intravenous acetaminophen attenuates lipid peroxidation in adults undergoing cardiopulmonary bypass: a randomized clinical trial.

BACKGROUND: Cardiopulmonary bypass (CPB) lyses erythrocytes and induces lipid peroxidation, indicated by increasing plasma concentrations of free hemoglobin, F2-isoprostanes, and isofurans. Acetaminophen attenuates hemeprotein-mediated lipid peroxidation, reduces plasma and urine concentrations of F2-isoprostanes, and preserves kidney function in an animal model of rhabdomyolysis. Acetaminophen also attenuates plasma concentrations of isofurans in children undergoing CPB. The effect of acetaminophen on lipid peroxidation in adults has not been studied. This was a pilot study designed to test the hypothesis that acetaminophen attenuates lipid peroxidation in adults undergoing CPB and to generate data for a clinical trial aimed to reduce acute kidney injury following cardiac surgery. METHODS AND RESULTS: In a prospective double-blind placebo-controlled clinical trial, sixty adult patients were randomized to receive intravenous acetaminophen or placebo starting prior to initiation of CPB and for every 6 hours for 4 doses. Acetaminophen concentrations measured 30 min into CPB and post-CPB were 11.9 ± 0.6 µg/mL (78.9 ± 3.9 µM) and 8.7 ± 0.3 µg/mL (57.6 ± 2.0 µM), respectively. Plasma free hemoglobin increased more than 15-fold during CPB, and haptoglobin decreased 73%, indicating hemolysis. Plasma and urinary markers of lipid peroxidation also increased during CPB but returned to baseline by the first postoperative day. Acetaminophen reduced plasma isofuran concentrations over the duration of the study (P = 0.05), and the intraoperative plasma isofuran concentrations that corresponded to peak hemolysis were attenuated in those subjects randomized to acetaminophen (P = 0.03). Perioperative acetaminophen did not affect plasma concentrations of F2-isoprostanes or urinary markers of lipid peroxidation. CONCLUSIONS: Intravenous acetaminophen attenuates the increase in intraoperative plasma isofuran concentrations that occurs during CPB, while urinary markers were unaffected. TRIAL REGISTRATION: ClinicalTrials.gov NCT01366976.

Hemodynamic instability in patients undergoing pulmonary embolectomy: institutional experience.

OBJECTIVES: Acute pulmonary embolism is a major cause of morbidity and mortality in patients presenting for emergent cardiac surgery with overall mortality ranging from 6% to as high as 85%. While the initial focus of treatment is nonsurgical or percutaneous interventions, surgical treatment continues to be a treatment for patients with refractory thrombus burden or cardiogenic shock. Our institution regularly performs surgical pulmonary embolectomy with improved outcomes compared to current reports. We thus performed a retrospective analysis of outcomes of pulmonary embolectomy patients and anesthetic management. DESIGN: A retrospective review of 40 patients undergoing emergent pulmonary embolectomy over a 4 year period (2008-2012) at our institution was performed to assess for a 2nd period of critical instability. SETTING: The study was conducted at a tertiary, level 1, trauma university medical center. PARTICIPANTS: The study was performed through chart review of patient hospital records. INTERVENTIONS: No interventions were performed. MEASUREMENTS: Anesthetic records were reviewed along with echocardiographic records and surgical reports to assess cardiac function, need for emergent cardiopulmonary bypass, and degree of patient morbidity. CONCLUSIONS: A total of 40 patients were studied. Hemodynamic instability occurred in 12.5% of patients at time of induction requiring emergent cardiopulmonary bypass. Another 17% of patients who remained stable following induction developed subsequent instability requiring emergent cardiopulmonary bypass during pericardial opening or manipulation which has not been previously reported. One patient died during hospitalization. Patients who required emergent bypass following induction of general anesthesia tended to receive higher doses of induction drugs than the other groups. In patients who needed emergent bypass during pericardial manipulation there were no identifiable factors suggesting that these patients remain at risk despite a stable post-induction course.