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1.
Ann Surg ; 277(1): 101-108, 2023 01 01.
Article in English | MEDLINE | ID: mdl-33214486

ABSTRACT

OBJECTIVE: To determine if implementation of a simplified ERP across multiple surgical specialties in different hospitals is associated with improved short and long-term mortality. Secondary aims were to examine ERP effect on length of stay, 30-day readmission, discharge disposition, and complications. SUMMARY BACKGROUND DATA: Enhanced recovery after surgery and various derivative ERPs have been successfully implemented. These protocols typically include elaborate sets of multimodal and multidisciplinary approaches, which can make implementation challenging or are variable across different specialties. Few studies have shown if a simplified version of ERP implemented across multiple surgical specialties can improve clinical outcomes. METHODS: A simplified ERP with 7 key domains (minimally invasive surgical approach when feasible, pre-/intra-operative multimodal analgesia, postoperative multimodal analgesia, postoperative nausea and vomiting prophylaxis, early diet advancement, early ambulation, and early removal of urinary catheter) was implemented in 5 academic and community hospitals within a single health system. Patients who underwent nonemergent, major orthopedic or abdominal surgery including hip/knee replacement, hepatobiliary, colorectal, gynecology oncology, bariatric, general, and urological surgery were included. Propensity-matched, retrospective case-control analysis was performed on all eligible surgical patients between 2014 and 2017 after ERP implementation or in the 12 months preceding ERP implementation (control population). RESULTS: A total of 9492 patients (5185 ERP and 4307 controls) underwent ERP eligible surgery during the study period. Three thousand three hundred sixty-seven ERP patients were matched by surgical specialty and hospital site to control non-ERP patients. Short and long-term mortality was improved in ERP patients: 30 day: ERP 0.2% versus control 0.6% ( P = 0.002); 1-year: ERP 3.9% versus control 5.1% ( P < 0.0001); 2-year: ERP 6.2% versus control 9.0% ( P < 0.0001). Length of stay was significantly lower in ERP patients (ERP: 3.9 ± 3.8 days; control: 4.8 ± 5.0 days, P < 0.0001). ERP patients were also less likely to be discharged to a facility (ERP: 11.3%; control: 14.8%, P < 0.0001). There was no significant difference for 30-day readmission. All complications except venous thromboembolism were significantly reduced in the ERP population (P < 0.02). CONCLUSIONS: A simplified ERP can uniformly be implemented across multiple surgical specialties and hospital types. ERPs improve short and long-term mortality, clinical outcomes, length of stay, and discharge disposition to home.


Subject(s)
Laparoscopy , Specialties, Surgical , Humans , Retrospective Studies , Hospitals, Community , Universities , Laparoscopy/methods , Length of Stay , Postoperative Complications
2.
Anesthesiology ; 138(4): 372-387, 2023 04 01.
Article in English | MEDLINE | ID: mdl-36724342

ABSTRACT

BACKGROUND: Neuraxial modulation, including spinal cord stimulation, reduces cardiac sympathoexcitation and ventricular arrhythmogenesis. There is an incomplete understanding of the molecular mechanisms through which spinal cord stimulation modulates cardiospinal neural pathways. The authors hypothesize that spinal cord stimulation reduces myocardial ischemia-reperfusion-induced sympathetic excitation and ventricular arrhythmias through γ-aminobutyric acid (GABA)-mediated pathways in the thoracic spinal cord. METHODS: Yorkshire pigs were randomized to control (n = 11), ischemia-reperfusion (n = 16), ischemia-reperfusion plus spinal cord stimulation (n = 17), ischemia-reperfusion plus spinal cord stimulation plus γ-aminobutyric acid type A (GABAA) or γ-aminobutyric acid type B (GABAB) receptor antagonist (GABAA, n = 8; GABAB, n = 8), and ischemia-reperfusion plus GABA transaminase inhibitor (GABAculine, n = 8). A four-pole spinal cord stimulation lead was placed epidurally (T1 to T4). GABA modulating pharmacologic agents were administered intrathecally. Spinal cord stimulation at 50 Hz was applied 30 min before ischemia. A 56-electrode epicardial mesh was used for high-resolution electrophysiologic recordings, including activation recovery intervals and ventricular arrhythmia scores. Immunohistochemistry and Western blots were performed to measure GABA receptor expression in the thoracic spinal cord. RESULTS: Cardiac ischemia led to myocardial sympathoexcitation with reduction in activation recovery interval (mean ± SD, -42 ± 11%), which was attenuated by spinal cord stimulation (-21 ± 17%, P = 0.001). GABAA and GABAB receptor antagonists abolished spinal cord stimulation attenuation of sympathoexcitation (GABAA, -9.7 ± 9.7%, P = 0.043 vs. ischemia-reperfusion plus spinal cord stimulation; GABAB, -13 ± 14%, P = 0.012 vs. ischemia-reperfusion plus spinal cord stimulation), while GABAculine alone caused a therapeutic effect similar to spinal cord stimulation (-4.1 ± 3.7%, P = 0.038 vs. ischemia-reperfusion). The ventricular arrhythmia score supported these findings. Spinal cord stimulation during ischemia-reperfusion increased GABAA receptor expression with no change in GABAB receptor expression. CONCLUSIONS: Thoracic spinal cord stimulation reduces ischemia-reperfusion-induced sympathoexcitation and ventricular arrhythmias through activation of GABA signaling pathways. These data support the hypothesis that spinal cord stimulation-induced release of GABA activates inhibitory interneurons to decrease primary afferent signaling from superficial dorsal horn to sympathetic output neurons in the intermediolateral nucleus.


Subject(s)
Myocardial Ischemia , Spinal Cord Stimulation , Animals , Arrhythmias, Cardiac , gamma-Aminobutyric Acid/physiology , Ischemia , Receptors, GABA , Spinal Cord/physiology , Spinal Cord Dorsal Horn , Swine
3.
Anesth Analg ; 136(2): 418-420, 2023 02 01.
Article in English | MEDLINE | ID: mdl-36638519

ABSTRACT

The first Cardiovascular Outcomes Research in Perioperative Medicine (COR-PM) conference took place on May 13, 2022, in Palm Springs, CA, and online. Here, we: (1) summarize the background, objective, and aims of the COR-PM meeting; (2) describe the conduct of the meeting; and (3) outline future directions for scientific meetings aimed at fostering high-quality clinical research in the broader perioperative medicine community.


Subject(s)
Perioperative Medicine , Outcome Assessment, Health Care
4.
Lancet ; 396(10245): 177-185, 2020 07 18.
Article in English | MEDLINE | ID: mdl-32682483

ABSTRACT

BACKGROUND: Atrial fibrillation and delirium are common consequences of cardiac surgery. Dexmedetomidine has unique properties as sedative agent and might reduce the risk of each complication. This study coprimarily aimed to establish whether dexmedetomidine reduces the incidence of new-onset atrial fibrillation and the incidence of delirium. METHODS: A randomised, placebo-controlled trial was done at six academic hospitals in the USA. Patients who had had cardiac surgery with cardiopulmonary bypass were enrolled. Patients were randomly assigned 1:1, stratified by site, to dexmedetomidine or normal saline placebo. Randomisation was computer generated with random permuted block size 2 and 4, and allocation was concealed by a web-based system. Patients, caregivers, and evaluators were all masked to treatment. The study drug was prepared by the pharmacy or an otherwise uninvolved research associate so that investigators and clinicians were fully masked to allocation. Participants were given either dexmedetomidine infusion or saline placebo started before the surgical incision at a rate of 0·1 µg/kg per h then increased to 0·2 µg/kg per h at the end of bypass, and postoperatively increased to 0·4 µg/kg per h, which was maintained until 24 h. The coprimary outcomes were atrial fibrillation and delirium occurring between intensive care unit admission and the earlier of postoperative day 5 or hospital discharge. All analyses were intention-to-treat. The trial is registered with ClinicalTrials.gov, NCT02004613 and is closed. FINDINGS: 798 patients of 3357 screened were enrolled from April 17, 2013, to Dec 6, 2018. The trial was stopped per protocol after the last designated interim analysis. Among 798 patients randomly assigned, 794 were analysed, with 400 assigned to dexmedetomidine and 398 assigned to placebo. The incidence of atrial fibrillation was 121 (30%) in 397 patients given dexmedetomidine and 134 (34%) in 395 patients given placebo, a difference that was not significant: relative risk 0·90 (97·8% CI 0·72, 1·15; p=0·34). The incidence of delirium was non-significantly increased from 12% in patients given placebo to 17% in those given dexmedetomidine: 1·48 (97·8% CI 0·99-2·23). Safety outcomes were clinically important bradycardia (requiring treatment) and hypotension, myocardial infarction, stroke, surgical site infection, pulmonary embolism, deep venous thrombosis, and death. 21 (5%) of 394 patients given dexmedetomidine and 8 (2%) of 396 patients given placebo, had a serious adverse event as determined by clinicians. 1 (<1%) of 391 patients given dexmedetomidine and 1 (<1%) of 387 patients given placebo died. INTERPRETATION: Dexmedetomidine infusion, initiated at anaesthetic induction and continued for 24 h, did not decrease postoperative atrial arrhythmias or delirium in patients recovering from cardiac surgery. Dexmedetomidine should not be infused to reduce atrial fibrillation or delirium in patients having cardiac surgery. FUNDING: Hospira Pharmaceuticals.


Subject(s)
Atrial Fibrillation/prevention & control , Cardiac Surgical Procedures/adverse effects , Delirium/prevention & control , Dexmedetomidine/administration & dosage , Hypnotics and Sedatives/administration & dosage , Drug Administration Schedule , Female , Humans , Infusions, Intravenous , Length of Stay/statistics & numerical data , Male , Middle Aged , Postoperative Complications/prevention & control , Treatment Outcome
5.
Anesthesiology ; 134(3): 405-420, 2021 03 01.
Article in English | MEDLINE | ID: mdl-33411921

ABSTRACT

BACKGROUND: Cardiac sympathoexcitation leads to ventricular arrhythmias. Spinal anesthesia modulates sympathetic output and can be cardioprotective. However, its effect on the cardio-spinal reflexes and network interactions in the dorsal horn cardiac afferent neurons and the intermediolateral nucleus sympathetic neurons that regulate sympathetic output is not known. The authors hypothesize that spinal bupivacaine reduces cardiac neuronal firing and network interactions in the dorsal horn-dorsal horn and dorsal horn-intermediolateral nucleus that produce sympathoexcitation during myocardial ischemia, attenuating ventricular arrhythmogenesis. METHODS: Extracellular neuronal signals from the dorsal horn and intermediolateral nucleus neurons were simultaneously recorded in Yorkshire pigs (n = 9) using a 64-channel high-density penetrating microarray electrode inserted at the T2 spinal cord. Dorsal horn and intermediolateral nucleus neural interactions and known markers of cardiac arrhythmogenesis were evaluated during myocardial ischemia and cardiac load-dependent perturbations with intrathecal bupivacaine. RESULTS: Cardiac spinal neurons were identified based on their response to myocardial ischemia and cardiac load-dependent perturbations. Spinal bupivacaine did not change the basal activity of cardiac neurons in the dorsal horn or intermediolateral nucleus. After bupivacaine administration, the percentage of cardiac neurons that increased their activity in response to myocardial ischemia was decreased. Myocardial ischemia and cardiac load-dependent stress increased the short-term interactions between the dorsal horn and dorsal horn (324 to 931 correlated pairs out of 1,189 pairs, P < 0.0001), and dorsal horn and intermediolateral nucleus neurons (11 to 69 correlated pairs out of 1,135 pairs, P < 0.0001). Bupivacaine reduced this network response and augmentation in the interactions between dorsal horn-dorsal horn (931 to 38 correlated pairs out of 1,189 pairs, P < 0.0001) and intermediolateral nucleus-dorsal horn neurons (69 to 1 correlated pairs out of 1,135 pairs, P < 0.0001). Spinal bupivacaine reduced shortening of ventricular activation recovery interval and dispersion of repolarization, with decreased ventricular arrhythmogenesis during acute ischemia. CONCLUSIONS: Spinal anesthesia reduces network interactions between dorsal horn-dorsal horn and dorsal horn-intermediolateral nucleus cardiac neurons in the spinal cord during myocardial ischemia. Blocking short-term coordination between local afferent-efferent cardiac neurons in the spinal cord contributes to a decrease in cardiac sympathoexcitation and reduction of ventricular arrhythmogenesis.


Subject(s)
Anesthesia, Spinal/methods , Arrhythmias, Cardiac/etiology , Arrhythmias, Cardiac/prevention & control , Myocardial Ischemia/complications , Neurons/drug effects , Spinal Cord/drug effects , Action Potentials/drug effects , Animals , Disease Models, Animal , Female , Male , Swine
6.
J Cardiothorac Vasc Anesth ; 35(1): 222-232, 2021 Jan.
Article in English | MEDLINE | ID: mdl-32888802

ABSTRACT

OBJECTIVE: In this paper, the authors report their experience of perioperative transthoracic echocardiography (TTE) practice and its impact on perioperative patient management. DESIGN: Retrospective case series. SETTING: Single institution, tertiary university hospital. PARTICIPANTS: A total of 101 adult ASA II-V male and female patients >18 years old who were scheduled for or having surgery were included in this retrospective case series. INTERVENTIONS: All patients underwent a focused perioperative TTE exam performed by cardiac anesthesiologists with significant TTE experience, and further clinical management was based on echocardiography findings discussed with the anesthesia care team. MEASUREMENTS: Significant echocardiographic findings and changes in patient management were reported. Step-up management was a new intervention that was executed based on echocardiographic findings (volume infusion, inotropic therapy, cardiology consultation, and other interventions), and step-down management was avoidance of an unnecessary intervention based on echocardiographic findings (proceeding to surgery without cancellation, delay, cardiology consultation, and additional investigations/interventions). MAIN RESULTS: Fifty-three percent of TTEs were performed in the preoperative setting, 34% were intra-operative, and 13% were postoperative. No significant findings were detected in 38 patients, leading to step-down management in all of them. Among patients with positive findings, left ventricular dysfunction (12.8%), hypovolemia (10.8%), and right ventricular dysfunction (7.9%) were the most common. Step-up therapy included inotropic/vasopressor therapy (24.8%), intensive care admission after surgery for further management (13.8%), volume infusion (12.8%), and other interventions (additional monitoring, surgical delay, cardiology consultation, and modification of surgical technique). CONCLUSION: Perioperative focused TTE examination is useful in the diagnosis of new cardiac conditions for anesthesia management (intraoperative monitoring and hemodynamic therapy) and postoperative care (intensive care unit admissions). Perioperative TTE performed by anesthesiologists can also help avoid procedural delays and unnecessary consults.


Subject(s)
Anesthesiologists , Echocardiography , Adolescent , Adult , Female , Hemodynamics , Humans , Male , Monitoring, Intraoperative , Retrospective Studies
7.
J Card Surg ; 36(10): 3501-3508, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34241917

ABSTRACT

BACKGROUND: Socioeconomic status (SES) can be a powerful predictor of adverse outcomes among heart failure patients but its impact on survival and readmission following left ventricular assist device (LVAD) implantation surgery is poorly understood. We investigated if the LVAD recipients from more deprived neighborhoods experienced higher mortality and readmission rate after device implantation as compared to those from less deprived areas. METHODS: This is a single center, retrospective analysis evaluating adults who received Heartmate III and Heartware HVAD implants between 2009 and 2018. SES indicators were area of deprivation index (ADI), race and income. Our cohort was grouped by ADI quartiles from least deprived (Q1), Q2, Q3 to the most deprived (Q4). Outcomes included overall mortality and readmission following surgery. RESULTS: A total of 191 patients were included in the study. Demographics by SES indicators demonstrated that least deprived (Q1) patients were older than the most deprived (65 vs. 57, p < .01), African-American patients originated from more deprived neighborhoods than Caucasians (ADI 87 vs. 62, p < .001), and high-income patients had higher preoperative BUN and creatinine. Outcome differences included a decreased risk of death in most deprived patients (Q4) compared to the least deprived (Q1), however after adjusting for age, LVAD indication, and INTERMACS profile this was no longer significant. No differences in survival or readmission by race or income was observed CONCLUSION: SES does not independently impact survival and readmission after Heartware HVAD and Heartmate III LVAD implantation. More studies are needed to evaluate if other SES factors affect these outcomes.


Subject(s)
Heart Failure , Heart-Assist Devices , Adult , Cohort Studies , Heart Failure/therapy , Humans , Retrospective Studies , Social Class , Treatment Outcome
8.
Br J Anaesth ; 123(4): 408-420, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31320115

ABSTRACT

Preoperative cardiac function is an important predictor of postoperative outcomes. Patients with heart failure are at higher risk of perioperative morbidity and mortality. Left ventricular ejection fraction, derived by standard echocardiography, is most frequently used to assess cardiac function in the intraoperative and postoperative periods. Myocardial strain analysis, a measurement of myocardial deformation, can provide additional information to left venricular eject fraction estimation. Here, we provide an overview of myocardial strain and different methods used to evaluate strain, including speckle tracking echocardiography. Speckle tracking echocardiography is an imaging modality that can analyse and track small segments of the myocardium, which provides greater detail for assessing global and regional cardiac motion and function. We further review the literature to illustrate the value of speckle tracking echocardiography-derived myocardial strain in describing cardiac function and its association with adverse surgical outcomes in the perioperative period, including low cardiac output states, need for inotropic support, postoperative arrhythmias, subclinical myocardial ischaemia, and length of hospital stay.


Subject(s)
Cardiac Surgical Procedures/methods , Heart/diagnostic imaging , Perioperative Care/methods , Echocardiography , Heart Function Tests , Humans , Image Interpretation, Computer-Assisted , Myocardium , Stroke Volume
9.
Anesth Analg ; 128(5): 854-864, 2019 05.
Article in English | MEDLINE | ID: mdl-30896605

ABSTRACT

BACKGROUND: Three-dimensional (3D) strain is an echocardiographic modality that can characterize left ventricular (LV) function with greater accuracy than ejection fraction. While decreases in global strain have been used to predict outcomes after cardiac surgery, changes in regional 3D longitudinal, circumferential, radial, and area strain have not been well described. The primary aim of this study was to define differential patterns in regional LV dysfunction after cardiac surgery using 3D speckle tracking strain imaging. Our secondary aim was to investigate whether changes in regional strain can predict postoperative outcomes, including length of intensive care unit stay and 1-year event-free survival. METHODS: In this prospective clinical study, demographic, operative, echocardiographic, and clinical outcome data were collected on 182 patients undergoing aortic valve replacement, mitral valve repair or replacement, coronary artery bypass graft, and combined cardiac surgery. Three-dimensional transthoracic echocardiograms were performed preoperatively and on the second to fourth postoperative day. Blinded analysis was performed for LV regional longitudinal, circumferential, radial, and area strain in the 17-segment model. RESULTS: Regional 3D longitudinal, circumferential, radial, and area strains were associated with differential patterns of myocardial dysfunction, depending on the surgical procedure performed and strain measure. Patients undergoing mitral valve repair or replacement had reduced function in the majority of myocardial segments, followed by coronary artery bypass graft, while patients undergoing aortic valve replacement had reduced function localized only to apical segments. After all types of cardiac surgery, segmental function in apical segments was reduced to a greater extent as compared to basal segments. Greater decrements in regional function were seen in circumferential and area strain, while smaller decrements were observed in longitudinal strain in all surgical patients. Both preoperative regional strain and change in regional strain preoperatively to postoperatively were correlated with reduced 1-year event-free survival, while postoperative strain was not predictive of outcomes. Only preoperative strain values were predictive of intensive care unit length of stay. CONCLUSIONS: Changes in regional myocardial function, measured by 3D strain, varied by surgical procedure and strain type. Differences in regional LV function, from presurgery to postsurgery, were associated with worsened 1-year event-free survival. These findings suggest that postoperative changes in myocardial function are heterogeneous in nature, depending on the surgical procedure, and that these changes may have long-term impacts on outcome. Therefore, 3D regional strain may be used to identify patients at risk for worsened postoperative outcomes, allowing early interventions to mitigate risk.


Subject(s)
Cardiac Surgical Procedures/adverse effects , Echocardiography, Three-Dimensional , Ventricular Dysfunction, Left/physiopathology , Aged , Coronary Artery Bypass , Critical Care , Disease-Free Survival , Echocardiography , Female , Humans , Image Processing, Computer-Assisted , Length of Stay , Male , Middle Aged , Mitral Valve/surgery , Observer Variation , Perioperative Period , Postoperative Period , Prospective Studies , Reproducibility of Results , Stress, Mechanical , Treatment Outcome
10.
Am J Physiol Heart Circ Physiol ; 315(6): H1592-H1601, 2018 12 01.
Article in English | MEDLINE | ID: mdl-30216122

ABSTRACT

The pathological consequences of ischemic heart disease involve signaling through the autonomic nervous system. Although early activation may serve to maintain hemodynamic stability, persistent aberrant sympathoexcitation contributes to the development of lethal arrhythmias and heart failure. We hypothesized that as the myocardium reacts and remodels to ischemic injury over time, there is an analogous sequence of gene expression changes in the thoracic spinal cord dorsal horn, the processing center for incoming afferent fibers from the heart to the central nervous system. Acute and chronic myocardial ischemia (MI) was induced in a large animal model of Yorkshire pigs, and the thoracic dorsal horn of treated pigs, along with control nonischemic pigs, was harvested for transcriptome analysis. We identified 32 differentially expressed genes between healthy and acute ischemia cohorts and 46 differentially expressed genes between healthy and chronic ischemia cohorts. The canonical immediate-early gene c-fos was upregulated after acute MI, along with fosB, dual specificity phosphatase 1 and 2 ( dusp1 and dusp2), and early growth response 2 (egr2). After chronic MI, there was a persistent yet unique activation of immediate-early genes, including fosB, nuclear receptor subfamily 4 group A members 1-3 ( nr4a1, nr4a2, and nr4a3), egr3, and TNF-α-induced protein 3 ( tnfaip3). In addition, differentially expressed genes from the chronic MI signature were enriched in pathways linked to apoptosis, immune regulation, and the stress response. These findings support a dynamic progression of gene expression changes in the dorsal horn with maturation of myocardial injury, and they may explain how early adaptive autonomic nervous system responses can maintain hemodynamic stability, whereas prolonged maladaptive signals can predispose patients to arrhythmias and heart failure. NEW & NOTEWORTHY Activation of the autonomic nervous system after myocardial injury can provide early cardiovascular support or prolonged aberrant sympathoexcitation. The later response can lead to lethal arrhythmias and heart failure. This study provides evidence of ongoing changes in the gene expression signature of the spinal cord dorsal horn as myocardial injury progresses over time. These changes could help explain how an adaptive nervous system response can become maladaptive over time.


Subject(s)
Genes, Immediate-Early , Myocardial Reperfusion Injury/genetics , Spinal Cord Dorsal Horn/metabolism , Animals , Dual-Specificity Phosphatases/genetics , Dual-Specificity Phosphatases/metabolism , Early Growth Response Protein 3/genetics , Early Growth Response Protein 3/metabolism , Myocardial Reperfusion Injury/metabolism , Orphan Nuclear Receptors/genetics , Orphan Nuclear Receptors/metabolism , Swine , Tumor Necrosis Factor alpha-Induced Protein 3/genetics , Tumor Necrosis Factor alpha-Induced Protein 3/metabolism , Up-Regulation
11.
Am J Physiol Heart Circ Physiol ; 313(2): H421-H431, 2017 Aug 01.
Article in English | MEDLINE | ID: mdl-28576833

ABSTRACT

Myocardial ischemia creates autonomic nervous system imbalance and can trigger cardiac arrhythmias. We hypothesized that neuromodulation by spinal cord stimulation (SCS) will attenuate local cardiac sympathoexcitation from ischemia-induced increases in afferent signaling, reduce ventricular arrhythmias, and improve myocardial function during acute ischemia. Yorkshire pigs (n = 20) were randomized to SCS (50 Hz at 200-µs duration, current 90% motor threshold) or sham operation (sham) for 30 min before ischemia. A four-pole SCS lead was placed percutaneously in the epidural space (T1-T4), and a 56-electrode mesh was placed over the heart for high-resolution electrophysiological recordings, including activation recovery intervals (ARIs), activation time, repolarization time, and dispersion of repolarization. Electrophysiological and hemodynamic measures were recorded at baseline, after SCS/sham, during acute ischemia (300-s coronary artery ligation), and throughout reperfusion. SCS 1) reduced sympathoexcitation-induced ARI and repolarization time shortening in the ischemic myocardium; 2) attenuated increases in the dispersion of repolarization; 3) reduced ventricular tachyarrythmias [nonsustained ventricular tachycardias: 24 events (3 sham animals) vs. 1 event (1 SCS animal), P < 0.001]; and 4) improved myocardial function (dP/dt from baseline to ischemia: 1,814 ± 213 to 1,596 ± 282 mmHg/s in sham vs. 1,422 ± 299 to 1,380 ± 299 mmHg/s in SCS, P < 0.01). There was no change in ventricular electrophysiology during baseline conditions without myocardial stress or in the nonischemic myocardium. In conclusion, in a porcine model of acute ventricular ischemia, SCS reduced regional myocardial sympathoexcitation, decreased ventricular arrhythmias, and improved myocardial function. SCS decreased sympathetic nerve activation locally in the ischemic myocardium with no effect observed in the normal myocardium, thus providing mechanistic insights into the antiarrhythmic and myocardial protective effects of SCS.NEW & NOTEWORTHY In a porcine model of ventricular ischemia, spinal cord stimulation decreased sympathetic nerve activation regionally in ischemic myocardium with no effect on normal myocardium, demonstrating that the antiarrhythmic effects of spinal cord stimulation are likely due to attenuation of local sympathoexcitation in the ischemic myocardium and not changes in global myocardial electrophysiology.


Subject(s)
Arrhythmias, Cardiac/prevention & control , Heart/innervation , Myocardial Ischemia/therapy , Spinal Cord Stimulation , Sympathetic Nervous System/physiopathology , Action Potentials , Animals , Arrhythmias, Cardiac/etiology , Arrhythmias, Cardiac/physiopathology , Disease Models, Animal , Female , Heart Rate , Male , Myocardial Ischemia/complications , Myocardial Ischemia/physiopathology , Sus scrofa , Time Factors , Ventricular Function, Left , Ventricular Pressure
12.
Anesthesiology ; 126(6): 1096-1106, 2017 06.
Article in English | MEDLINE | ID: mdl-28358748

ABSTRACT

BACKGROUND: Imbalances in the autonomic nervous system, namely, excessive sympathoexcitation, contribute to ventricular tachyarrhythmias. While thoracic epidural anesthesia clinically suppresses ventricular tachyarrhythmias, its effects on global and regional ventricular electrophysiology and electrical wave stability have not been fully characterized. The authors hypothesized that thoracic epidural anesthesia attenuates myocardial excitability and the proarrhythmic effects of sympathetic hyperactivity. METHODS: Yorkshire pigs (n = 15) had an epidural catheter inserted (T1 to T4) and a 56-electrode sock placed on the heart. Myocardial excitability was measured by activation recovery interval, dispersion of repolarization, and action potential duration restitution at baseline and during programed ventricular extrastimulation or left stellate ganglion stimulation, before and 30 min after thoracic epidural anesthesia (0.25% bupivacaine). RESULTS: After thoracic epidural anesthesia infusion, there was no change in baseline activation recovery interval or dispersion of repolarization. During programmed ventricular extrastimulation, thoracic epidural anesthesia decreased the maximum slope of ventricular electrical restitution (0.70 ± 0.24 vs. 0.89 ± 0.24; P = 0.021) reflecting improved electrical wave stability. Thoracic epidural anesthesia also reduced myocardial excitability during left stellate ganglion stimulation-induced sympathoexcitation through attenuated shortening of activation recovery interval (-7 ± 4% vs. -4 ± 3%; P = 0.001), suppression of the increase in dispersion of repolarization (313 ± 293% vs. 185 ± 234%; P = 0.029), and reduction in sympathovagal imbalance as measured by heart rate variability. CONCLUSIONS: Our study describes the electrophysiologic mechanisms underlying antiarrhythmic effects of thoracic epidural anesthesia during sympathetic hyperactivity. Thoracic epidural anesthesia attenuates ventricular myocardial excitability and induces electrical wave stability through its effects on activation recovery interval, dispersion of repolarization, and the action potential duration restitution slope.


Subject(s)
Anesthesia, Epidural/methods , Bupivacaine/pharmacology , Electrophysiological Phenomena/drug effects , Heart Rate/drug effects , Heart Ventricles/drug effects , Action Potentials/drug effects , Anesthetics, Local/pharmacology , Animals , Electric Stimulation , Female , Male , Models, Animal , Swine
13.
Anesth Analg ; 124(2): 419-428, 2017 02.
Article in English | MEDLINE | ID: mdl-27782943

ABSTRACT

BACKGROUND: Echocardiography-based speckle-tracking strain imaging is an emerging modality to assess left ventricular function. The aim of this study was to investigate the change in left ventricular systolic function after cardiac surgery with 3-dimensional (3D) speckle-tracking strain imaging and to determine whether preoperative 3D strain is an independent predictor of acute and long-term clinical outcomes after aortic valve, mitral valve, and coronary artery bypass grafting operations. METHODS: In total, 163 adult patients undergoing aortic valve, mitral valve, and coronary artery bypass surgeries were enrolled prospectively and had complete data sets. Demographic, operative, and outcome data were collected. 3D transthoracic echocardiograms were preformed preoperatively and on second to fourth postoperative day. Blinded off-line analysis was performed for left ventricular 2-dimensional (2D) ejection fraction (EF2D) and 3D ejection fraction (EF3D) and global peak systolic area, longitudinal, circumferential, and radial strain. RESULTS: 3D global strain correlated well with EF3D. Ventricular function as measured by strain imaging decreased significantly after all types of cardiac surgery. When preoperative EF3D was used, receiver operating characteristic curves identified reference values for 3D global strain corresponding to normal, mildly reduced, and severely reduced ventricular function. Normal ventricular function (EF3D ≥ 50%) corresponded to 3D global area strain -25%, with area under curve = 0.86 (0.81-0.89). Patients with reduced preoperative 3D global area strain had worse postoperative outcomes, including length of intensive care unit stay (4 vs 3 days, P = .001), major adverse events (27% vs 11%, P = .03), and decreased 1-year event-free survival (69% vs 88%, P = .005). After we controlled for baseline preoperative risk models including European System for Cardiac Operative Risk Evaluation score and surgery type, preoperative strain was an independent predictor of both short- and long-term outcomes, including length of intensive care unit stay, postoperative inotrope score, and 1-year event-free survival. CONCLUSIONS: This study shows that cardiac surgery was associated with an acute reduction in postoperative left ventricular function, when evaluated with 3D strain imaging. In addition, preoperative 3D strain was demonstrated to be an independent predictor of acute and long-term clinical outcomes after cardiac surgery. The use of noninvasive 3D transthoracic echocardiogram strain imaging before cardiac surgery may provide added information to aid in perioperative risk stratification and management for these high-risk patients.


Subject(s)
Cardiac Surgical Procedures/methods , Heart Ventricles/diagnostic imaging , Ventricular Function, Left , Adult , Aged , Aortic Valve/surgery , Cardiac Surgical Procedures/adverse effects , Coronary Artery Bypass , Echocardiography , Echocardiography, Three-Dimensional , Female , Humans , Male , Middle Aged , Mitral Valve/surgery , Predictive Value of Tests , Prospective Studies , Reproducibility of Results , Risk Assessment , Survival Analysis , Treatment Outcome
14.
Am J Physiol Regul Integr Comp Physiol ; 310(5): R414-21, 2016 Mar 01.
Article in English | MEDLINE | ID: mdl-26661096

ABSTRACT

Sympathoexcitation is associated with ventricular arrhythmogenesis. The aim of this study was to determine the role of thoracic dorsal root afferent neural inputs to the spinal cord in modulating ventricular sympathetic control of normal heart electrophysiology. We hypothesize that dorsal root afferent input tonically modulates basal and evoked efferent sympathetic control of the heart. A 56-electrode sock placed on the epicardial ventricle in anesthetized Yorkshire pigs (n = 17) recorded electrophysiological function, as well as activation recovery interval (ARI) and dispersion in ARI, at baseline conditions and during stellate ganglion electrical stimulation. Measures were compared between intact states and sequential unilateral T1-T4 dorsal root transection (DRTx), ipsilateral ventral root transection (VRTx), and contralateral dorsal and ventral root transections (DVRTx). Left or right DRTx decreased global basal ARI [Lt.DRTx: 369 ± 12 to 319 ± 13 ms (P < 0.01) and Rt.DRTx: 388 ± 19 to 356 ± 15 ms (P < 0.01)]. Subsequent unilateral VRTx followed by contralateral DRx+VRTx induced no further change. In intact states, left and right stellate ganglion stimulation shortened ARIs (6 ± 2% vs. 17 ± 3%), while increasing dispersion (+139% vs. +88%). There was no difference in magnitude of ARI or dispersion change with stellate stimulation following spinal root transections. Interruption of thoracic spinal afferent signaling results in enhanced basal cardiac sympathoexcitability without diminishing the sympathetic response to stellate ganglion stimulation. This suggests spinal dorsal root transection releases spinal cord-mediated tonic inhibitory control of efferent sympathetic tone, while maintaining intrathoracic cardiocentric neural networks.


Subject(s)
Heart Rate , Heart Ventricles/innervation , Spinal Cord/physiology , Spinal Nerve Roots/physiology , Sympathetic Nervous System/physiology , Ventricular Function, Left , Action Potentials , Animals , Arrhythmias, Cardiac/physiopathology , Electric Stimulation , Female , Laminectomy , Male , Models, Animal , Neural Inhibition , Neurons, Afferent/physiology , Neurons, Efferent/physiology , Spinal Cord/surgery , Spinal Nerve Roots/surgery , Stellate Ganglion/physiology , Swine , Ventricular Pressure
15.
Anesthesiology ; 125(1): 221-9, 2016 Jul.
Article in English | MEDLINE | ID: mdl-27119434

ABSTRACT

BACKGROUND: This multicenter, retrospective study was conducted to determine how resident performance deficiencies affect graduation and board certification. METHODS: Primary documents pertaining to resident performance were examined over a 10-yr period at four academic anesthesiology residencies. Residents entering training between 2000 and 2009 were included, with follow-up through February 2016. Residents receiving actions by the programs' Clinical Competency Committee were categorized by the area of deficiency and compared to peers without deficiencies. RESULTS: A total of 865 residents were studied (range: 127 to 275 per program). Of these, 215 residents received a total of 405 actions from their respective Clinical Competency Committee. Among those who received an action compared to those who did not, the proportion graduating differed (93 vs. 99%, respectively, P < 0.001), as did the proportion achieving board certification (89 vs. 99%, respectively, P < 0.001). When a single deficiency in an Essential Attribute (e.g., ethical, honest, respectful behavior; absence of impairment) was identified, the proportion graduating dropped to 55%. When more than three Accreditation Council for Graduate Medical Education Core Competencies were deficient, the proportion graduating also dropped significantly. CONCLUSIONS: Overall graduation and board certification rates were consistently high in residents with no, or isolated, deficiencies. Residents deficient in an Essential Attribute, or multiple competencies, are at high risk of not graduating or achieving board certification. More research is needed on the effectiveness and selective deployment of remediation efforts, particularly for high-risk groups.


Subject(s)
Anesthesiology/education , Anesthesiology/standards , Internship and Residency/standards , Accreditation , Certification , Clinical Competence , Communication , Education, Medical, Graduate/standards , Educational Measurement , Health Knowledge, Attitudes, Practice , Humans , Professional Role , Retrospective Studies
17.
J Cardiothorac Vasc Anesth ; 29(4): 845-51, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25990266

ABSTRACT

OBJECTIVES: The primary aim of this study was to use speckle-tracking strain imaging to evaluate the effect of general anesthesia (GA) and positive-pressure ventilation (PPV) on left atrial (LA) mechanics. The authors hypothesized that GA and PPV would be associated with a decrease in LA strain. The secondary aims were to investigate the effects of GA and PPV on traditional Doppler-derived measures of LA function and Doppler echocardiographic grade of diastolic function. DESIGN: A prospective observational study. SETTING: A university hospital. PARTICIPANTS: Adult patients undergoing cardiac surgery. INTERVENTIONS: Transthoracic echocardiography was performed at baseline and under GA with PPV. MEASUREMENTS AND MAIN RESULTS: Changes in LA function associated with GA and PPV were assessed using LA speckle-tracking strain imaging. A reduction was observed in LA peak longitudinal strain (24% v 18%, p<0.001) and preatrial contraction strain (13% v 8%, p<0.001). No difference was seen in LA contraction strain or atrial ejection fraction. Indexed LA volume and Doppler diastolic indices also were reduced significantly, and 39% of patients had a change in measured diastolic grade under GA with PPV. CONCLUSIONS: Speckle-tracking strain imaging of the left atrium demonstrated that GA and PPV had a significant impact on LA mechanics by decreasing strain measures of LA preload, with a lesser effect on LA contractility.


Subject(s)
Anesthesia, General/adverse effects , Atrial Function, Left/physiology , Echocardiography/methods , Heart Atria/diagnostic imaging , Positive-Pressure Respiration/adverse effects , Aged , Female , Humans , Male , Middle Aged , Prospective Studies
18.
Am J Ther ; 21(4): 288-95, 2014.
Article in English | MEDLINE | ID: mdl-22975661

ABSTRACT

Since the advent of neonatal cardiac surgery in the 1970s, an increasing number of patients suffering from congenital heart disease (CHD) have survived into adulthood. In 2010, it is estimated that 1.2 million or 1 in 150 of young adults have some form of CHD in the United States. Current birth, incidence, and survival rate predict an increase in the CHD population between 10,000 and 300,000 patients per year. Data from large adult CHD (ACHD) centers (UCLA, Toronto, Mayo Clinic) show that as many as 50% of these patients with complex physiology are 40 years of age or older and that two-thirds of them can be categorized as medium or high risk to demonstrate signs and symptoms of low cardiac output. As this population ages, it is very likely for hospital-based physicians to encounter such patients in their procedural and/or surgical practice. Risk stratification and interdisciplinary approach in the care of these patients will assure a safe outcome. The assessment of the patient must consider the variable expression of CHD. Because most lesions are "fixed but not cured," the periprocedural practitioner must consider the altered physiology of the heart in context of the physiological challenges of percutaneous and open surgical interventions. The 2008 American Heart Association/American College of Cardiology guidelines for the Management of Adults with CHD establish for the first time a streamlined approach to the care of these patients. This review will apply these guidelines to the patients with ACHD undergoing noncardiac surgery and intervention.


Subject(s)
Heart Defects, Congenital/physiopathology , Perioperative Care/methods , Practice Guidelines as Topic , Adult , American Heart Association , Humans , Societies, Medical , Surgical Procedures, Operative/methods , United States
19.
20.
Anesth Analg ; 116(6): 1295-308, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23558832

ABSTRACT

BACKGROUND: Red blood cell (RBC) transfusions are associated with increased morbidity. Children receiving heart transplants constitute a unique group of patients due to their risk factors. Although previous studies in nontransplant patients have focused primarily on the effects of postoperative blood transfusions, a significant exposure to blood occurs during the intraoperative period, and a larger percentage of heart transplant patients require intraoperative blood transfusions when compared with general cardiac surgery patients. We investigated the relationship between clinical outcomes and the amount of blood transfused both during and after heart transplantation. We hypothesized that larger amounts of RBC transfusions are associated with worsening clinical outcomes in pediatric heart transplant patients. METHODS: A database comprising 108 pediatric patients undergoing heart transplantation from 2004 to 2010 was queried. Preoperative and postoperative clinical risk factors, including the amount of blood transfused intraoperatively and 48 hours postoperatively, were analyzed. The outcome measures were length of hospital stay, duration of tracheal intubation, inotrope score, and major adverse events. Bivariate and multivariate analyses were performed to control for simultaneous risk factors and determine outcomes in which the amount of blood transfused was an independent risk factor. RESULTS: Ninety-four patients with complete datasets were included in the final analysis. Eighty-eight percent received RBC transfusions, with a median transfusion amount of 38.7 mL/kg. A multivariate analysis correcting for 8 covariate risk factors, including the Index for Mortality Prediction After Cardiac Transplantation, age, weight, United Network for Organ Sharing status, warm and cold ischemia time, repeat sternotomy, and pretransplant hematocrit, showed RBC transfusions were independently associated with increased length of intensive care unit stay (means ratio = 1.34; 95% confidence interval, 1.03-1.76; P = 0.03), and increased inotrope score in the first postoperative 24 hour (mean ratio = 1.26; 95% confidence interval, 1.04-1.52; P = 0.04). Patients suffering major adverse events received significantly larger median amounts of blood RBC transfusions (P = 0.002). Transfusions >60 mL/kg were also associated with increased risk of major adverse events (accuracy 76%) including postoperative sepsis, extracorporeal membrane oxygenation, open chest, dialysis, and graft failure. CONCLUSION: The majority of pediatric patients undergoing orthotropic heart transplantation receive RBC transfusions, with the largest amount transfused in the operating room. Escalating amounts of RBC transfusions are independently associated with increased length of intensive care unit stay, inotrope scores, and major adverse events. Since heart allografts are a limited resource, improvement in the blood transfusion and conservation practices can enhance clinical outcomes in pediatric heart transplant patients.


Subject(s)
Erythrocyte Transfusion/adverse effects , Heart Transplantation/adverse effects , Adolescent , Child , Child, Preschool , Female , Heart Transplantation/mortality , Humans , Infant , Intensive Care Units , Length of Stay , Male , Outcome Assessment, Health Care
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