Analysis of Maternal and Fetal Oxidative Stress During Delivery with Epidural Analgesia.

Childbirth is a stressful event for mothers, and labor epidural analgesia (LEA) may reduce mental stress. Mental stressors include labor pain, fear, and anxiety, which induce oxidative stress. In this study, we focused on oxidative stress during delivery and conducted a cross-sectional analysis of maternal and fetal oxidative stress. The participants included 15 women who received LEA (LEA group) and 15 who did not (No LEA group). Participants with a gestational age of < 37 weeks, BMI of ≥ 35 kg/m2, cerebrovascular or cardiovascular complications, multiple pregnancies, gestational hypertension, gestational diabetes, chronic hypertension, thyroid disease, birth weight of < 2,500 g, emergency cesarean section, or cases in which epidural anesthesia was re-administered during delivery were excluded from the study. Maternal blood was collected on admission, and immediately after delivery, and umbilical artery blood was collected from the fetus. The oxidative stress status was assessed by measuring diacron-reactive oxygen metabolite (an index of the degree of lipid peroxide oxidation), biological antioxidant potential (an index of antioxidant capacity) and calculating the ratio of BAP/d-ROMs (an index of the oxidative stress). The results showed that maternal oxidative stress immediately after delivery was lower in the LEA group than in the No LEA group. Moreover, the fetuses experienced less oxidative stress in the LEA group than in the No LEA group. Taken together, these results suggest that LEA may reduce maternal and fetal oxidative stress associated with childbirth.

Outcomes of severe peripartum cardiomyopathy and mechanical circulatory support: a case series.

BACKGROUND: We present three cases of severe peripartum cardiomyopathy (PPCM) that required mechanical circulatory supports. CASE PRESENTATION: Case 1: A 33-year-old woman developed acute heart failure (AHF) after normal spontaneous delivery. Intra-aortic balloon pump (IABP) was inserted on postpartum day (PD) 10 with a peripartum cardiomyopathy (PPCM), which was withdrawn on PD 30 after medical treatment including anti-prolactin drugs. Case 2: A 44-year-old woman developed AHF 1 month after vaginal delivery. IABP or extra-corporeal membrane oxygenation (ECMO) was not effective and a biventricular assist device was inserted. It was withdrawn on PD 85 after improvement of left ventricular ejection fraction (LVEF). Case3: A 37-year-old woman was transferred with a diagnosis of PPCM. Cardiac function unimproved by IABP or ECMO, and a left ventricular assist device was implanted. It was withdrawn on PD 386 after recovery of LVEF. CONCLUSION: All the cases with PPCM recovered after mechanical circulatory supports and resumed social lives.

Use of Continuous Electrical Impedance Measurement for Accurate Nerve Block in Rabbits.

OBJECTIVE: To perform an effective and safe nerve block, the needle must be placed near the target nerve while avoiding nerve damage. Our objective was to conduct an animal study to determine whether changes in electrical impedance (EI) could be used to guide the needle and achieve a safe and accurate nerve block. METHODS: We measured the EI of rabbit tissues during ultrasound-guided sciatic nerve block using a bipolar needle via the in-plane needle approach. The EI values and needle track on the ultrasound monitor were video-recorded. When there was a change in the EI, the needle advancement was stopped, and a stained anesthetic was injected. Subsequently, the animals were euthanized, and the anesthetic-stained tissue was examined via dissection, while the other tissue was preserved at -80°C for microscopic analysis. RESULTS: The EI remained stable as the needle advanced through the muscle (extraneural); however, it markedly decreased when the needle tip contacted the nerve or slightly punctured the epineurium (paraneural). The mean extra- and paraneural EIs were 4.92 ± 1.31 kΩ (range, 2.39-9.67 kΩ) and 2.86 ± 0.96 kΩ (range, 1.66-5.13 kΩ), respectively. Examination of the dissections and cryostat sections showed anesthetic delivery around the nerve. CONCLUSIONS: EI values differed between extra- and paraneural sites, and monitoring these values allowed prediction of the needle tip location with respect to the target nerve. Real-time EI measurement could improve the nerve block.

A case of amniotic fluid embolism successfully treated by multidisciplinary treatment.

BACKGROUND: Amniotic fluid embolism (AFE) is a life-threatening obstetric emergency. Because the maternal mortality associated with AFE is very high, early recognition and prompt treatment are important for improving the prognosis. We report a case of amniotic fluid embolism successfully treated by multidisciplinary treatment. CASE PRESENTATION: A 39-year-old woman with fetal congenital heart anomaly and polyhydramnios was scheduled for induction of delivery at 37 weeks of gestation with labor epidural analgesia. Uncontrollable bleeding occurred 30 min after vaginal delivery. Based on the clinical diagnosis of AFE, massive blood transfusion, insertion of an aortic occlusion balloon catheter, and hysterectomy was performed. Total blood loss was 12,000 mL. The diagnosis of AFE was confirmed by pathological examination. She was discharged with no complications. CONCLUSION: We report a case of AFE who were rescued by prompt diagnosis and treatment.

Successful pulmonary embolectomy for massive pulmonary embolism during pregnancy: a case report.

BACKGROUND: Pulmonary embolism (PE) resulting from venous thromboembolism is a leading cause of maternal mortality in pregnancy. In patients with massive PE and hemodynamic instability, the treatment options often considered are thrombolytics, inferior vena caval filters, or embolectomy. We report here the case of a patient with massive PE at 28 weeks' gestation, who underwent emergency pulmonary embolectomy via cardiopulmonary bypass. CASE PRESENTATION: A 35-year old primigravida with a history of massive PE at 25 weeks of gestation was referred to our hospital at 28 weeks of gestation, following treatment failure after insertion of an inferior vena cava filter and heparin administration. Emergency thrombectomy was performed, and intracardiac echography was used for intraoperative fetal heart rate monitoring. However, the patient developed hemodynamic collapse following anesthesia induction; hence, emergency cardiopulmonary bypass (CPB) was performed via median sternotomy. Thrombectomy and tricuspid valve plication were performed under cardiac arrest. After confirming postoperative hemostasis, heparin administration was resumed. At 40 weeks of gestation, labor was induced under epidural analgesia. Both mother and child were discharged with no complications. CONCLUSION: In conclusion, intracardiac echography is useful for fetal heart rate monitoring during emergency cardiac surgery in pregnancy. Careful CPB management is important to maintain uteroplacental blood flow. Although there is no consensus on the delivery methods in such cases, epidural analgesia during labor was useful in reducing cardiac load and wound traction.

A case of laparotomic cholecystectomy in a patient with biventricular assist devices.

We describe a patient with biventricular assist devices who had systemic inflammation because of cholecystitis that required open cholecystectomy, and we discuss the anesthetics and monitors that should be used in unstable patients with ventricular assist devices (VADs) who are undergoing major surgery. The patient was a 40-year-old man in the dilated phase of hypertrophic obstructive cardiomyopathy, who was implanted with an internal left VAD and external right VAD. We anesthetized the patient with a combination of a low dose of sevoflurane and ketamine to minimize vasodilation. We chose ketamine because we expected it to have a postoperative analgesic effect. An INVOS™ (Medtronic) monitor was beneficial, especially since the pulse oximeter did not work because of a pulse deficit. The FloTrach™ (Edwards Lifesciences) failed to measure the stroke volume and its variability. The left VAD, the Jarvik2000, did not show its flow rate. However, we were able to estimate that the flow was stabilized, because the flow rate of the right VAD was stable, and there was no significant change in both ventricles and septa, as shown on transesophageal echocardiography.

Periarteritis in lung from a continuous-flow right ventricular assist device: role of the local Renin-Angiotensin system.

BACKGROUND: We previously reported renal arterial periarteritis after implantation of a continuous-flow left ventricular assist device in calves. The purpose of the present study was to investigate whether the same periarteritis changes occur in the intrapulmonary arteries after implantation of a continuous-flow right ventricular assist device (CFRVAD) in calves and to determine the mechanism of those histologic changes. METHODS: Ten calves were implanted with a CFRVAD for 29 ± 7 days, and we compared pulmonary artery samples and hemodynamic data before and after CFRVAD implantation prospectively. RESULTS: After implantation, the pulsatility index (pulmonary arterial pulse pressure/pulmonary arterial mean pressure) significantly decreased (0.88 ± 0.40 before vs 0.51 ± 0.22 after; p < 0.05), with severe periarteritis of the intrapulmonary arteries in all animals. Periarterial pathology included hyperplasia and inflammatory cell infiltration. The number of inflammatory cells positive for the angiotensin II type 1 receptor was significantly higher after implantation (7.8 ± 6.5 pre-CFRVAD vs 313.2 ± 145.2 at autopsy; p < 0.01). Serum angiotensin-converting enzyme activity significantly decreased after implantation from 100% to 49.7 ± 17.7% at week 1 (p = 0.01). Tissue levels of angiotensin-converting enzyme also demonstrated a significant reduction (0.381 ± 0.232 before implantation vs 0.123 ± 0.096 at autopsy; p = 0.043). CONCLUSIONS: Periarteritis occurred in the intrapulmonary arteries of calves after CFRVAD implantation. The local renin-angiotensin system (not the angiotensin-converting enzyme pathway) plays an important role in such changes.

Does general anesthesia increase the diagnostic yield of endoscopic ultrasound-guided fine needle aspiration of pancreatic masses?

BACKGROUND: : Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) of the pancreas has become the preferred method for tissue diagnosis for pancreatic solid masses. The yield of EUS-FNA in this setting is influenced by multiple factors. We hypothesized that general anesthesia (GA) may improve EUS-FNA yield by improving patient cooperation and stillness during the procedure. Our objective was to assess the association between the sedation method employed and the diagnostic yield of EUS-FNA. METHODS: : A retrospective cohort study was conducted involving consecutive patients who received EUS-FNA for diagnosis of a solid pancreatic mass at the Cleveland Clinic (Cleveland, OH) gastrointestinal endoscopy units from 2007 to 2009. We compared the diagnostic yield of EUS-FNA between patients receiving GA provided by an anesthesiologist (GA group) and patients receiving conscious sedation (CS) provided by a qualified registered nurse (CS group). RESULTS: : Of 371 patients, a cytological diagnosis was obtained in 73/88 patients (83%) in the GA group and 206/283 patients (73%) in the CS group. Anesthesiologist-delivered GA was associated with an increased odds of having a successful diagnosis as compared with CS (adjusted odds ratio [95% CI]: 2.56 [1.27-5.17], P = 0.01). However, the incidence of complication during or after the procedure was not different between the groups (P > 0.99). CONCLUSIONS: : Anesthesiologist-delivered GA was associated with a significantly higher diagnostic yield of EUS-FNA. GA should be considered a preferred sedation method for EUS-FNA of a solid pancreatic mass.

[A day in the busy obstetric unit from the anesthesiologist point of view, experience at the Cleveland clinic; Cleveland, Ohio].

Cleveland Clinic Labor and Delivery Unit is a syntactical delivery facility and comprised of 16 delivery rooms, 3 operating rooms, 3 triage rooms, and 1 recovery room that has a capacity of 6 beds, 43 postpartum rooms, 2 nurseries, and 1 neonatal intensive care unit (NICU). Cleveland Clinic Labor and Delivery Unit (LDU) had 3,691 delivery cases in 2007. The ratio of neuraxial analgesia (NA) during labor is 84.2% (2,348/ 2,787), using epidural anesthesia or combined spinalepidural anesthesia (CSEA). This article introduces the obstetrical (OB) anesthesia practice at the Cleveland Clinic and our novel anesthetic regime as typical of one typical busy day.

[Obstetric anesthesia training in the USA, experience of the Cleveland Clinic; Cleveland, Ohio].

In Japan, the re-organization of obstetrical medical system is needed and this project is ongoing under Japanese government initiative. However the ratio of using neuraxial analgesia (NA) during labor in Japan has been low and, increased demand for NA during labor is anticipated in near future. To prepare for these demands, the adequate number of obstetrical (OB) anesthesia specialists in the advanced OB hospital is necessary. However, there is no official training program for OB anesthesiologists in Japan. This article reports the clinical practice of the OB anesthesia in one of the biggest hospitals in the United State, the Cleveland Clinic, from the view of an OB anesthesia clinical fellow.

Novel implantable device to detect cardiac allograft rejection.

BACKGROUND: Allograft rejection remains the nemesis of solid organ transplantation. Soul Mate is a novel implantable wireless data transmission system that analyzes 9 intramyocardial electrogram parameters recorded from 4 or 6 configurations of 2 or 3 epicardial leads to detect allograft rejection. This study determined the ability of the Soul Mate to detect early rejection of transplanted hearts. METHODS AND RESULTS: Five dogs underwent heterotopic cervical heart transplantation and simultaneous implantation of the Soul Mate's Cardiac Rejection Monitoring Device. Dogs were initially immunosuppressed, but subsequent drug discontinuation allowed allograft rejection to appear. Allograft biopsies were performed at regular intervals to determine rejection grade, which was compared to a calculated rejection score determined as percent change from baseline of values for each intramyocardial electrogram. There was significant correlation between the biopsy results and the evolution of 5 parameters. The strongest correlation (r=0.939; P<0.001) was obtained using the "general median" parameter from 4 configurations, assessed 1 day before the biopsy, with a sensitivity of 85.7% and a specificity of 100% compared to the myocardial biopsy results. CONCLUSIONS: The Soul Mate allograft rejection monitoring system accurately detected transplanted heart rejection in a canine model noninvasively with continuous sampling. This proof-of-concept study suggests that the Soul Mate could be used to more intensely and more frequently monitor cardiac allografts for rejection.

Human clinical fitting study of the DexAide right ventricular assist device.

The DexAide right ventricular assist device (RVAD) has been developed as an implantable RVAD. The purpose of this study was to determine the final design and optimal anatomical placement of the DexAide RVAD when implanted simultaneously with either of two commercially available left ventricular assist devices (LVADs) in patients. A mock-up DexAide RVAD was used to assess configuration with each of two types of commercially available LVADs at the time of LVAD implantation in three human clinical cases. The pump body of the DexAide RVAD was placed either in the preperitoneal space or in the right thoracic cavity. The DexAide RVAD placed into the right thoracic cavity is suitable for use with the Novacor or HeartMate II LVADs. The results of this study will guide the finalization of the inflow cannula and optimal placement of the DexAide RVAD for human clinical trials.

Heart rate variability in a progressive heart failure model with rapid ventricular pacing.

BACKGROUND: Heart rate variability (HRV) is an indicator of autonomic nervous system functionality and a recognized predictor of cardiac death; however, the changes in HRV occurring in progressive heart failure are not fully understood. The purpose of this study was to evaluate the progressive changes of autonomic system activity in progressive heart failure by rapid ventricular pacing in an animal model. METHODS: Heart failure was induced in 13 mongrel dogs (27.8 +/- 3.7 kg) by rapid ventricular pacing (230 beats/min) for 4 weeks and maintenance of pacing at a reduced rate (190 beats/min) for 2 weeks. Time domain analysis and spectral analysis of HRV were performed with the MemCalc system after 30 minutes of pacing cessation every week. Hemodynamic and echocardiographic data were obtained before and after induction of heart failure. RESULTS: Cardiac output decreased significantly (3.6 L/min versus 1.6 L/min, P < .001) after 6 weeks of ventricular pacing. Significantly increased were the heart rate (126 beats/min versus 138 beats/min, P < .05), left ventricular end-diastolic pressure (9.1 mm Hg versus 30.9 mm Hg, P < .001), and pulmonary capillary wedge pressure (8.0 mm Hg versus 18.7 mm Hg, P < .001). High-frequency components progressively decreased. Low-frequency components progressively decreased except at 5 weeks after the pacing. A ratio of low- to high-frequency components increased in moderate heart failure and decreased in severe heart failure. CONCLUSIONS: Changes in the high-frequency component and low-frequency component are important for assessing heart failure in progressive heart failure. Serial follow-up measurements of HRV might be helpful for patients with such disease.

A novel device for left atrial appendage exclusion: the third-generation atrial exclusion device.

OBJECTIVE: Occlusion of the left atrial appendage is proposed to reduce the risk of stroke in patients with atrial fibrillation. The third-generation atrial exclusion device, modified to provide uniform distribution of pressure at appendage exclusion, was assessed for safety and effectiveness in a canine model and compared with a surgical stapler. METHODS: The atrial exclusion device consists of 2 parallel, straight, rigid titanium tubes and 2 nitinol springs with a knit-braided polyester fabric. Fourteen mongrel dogs were implanted with the device at the base of the left atrial appendage via a median sternotomy. In each dog, the right atrial appendage was stapled with a commercial apparatus for comparison. The animals were evaluated at 7 days (n = 3), 30 days (n = 5), and 90 days (n = 6) after implantation by epicardial echocardiography, left atrial and coronary angiography, gross pathology, and histology. RESULTS: Left atrial appendage exclusion was complete and achieved without hemodynamic instability, and coronary angiography revealed that the left circumflex artery was patent in all cases. A new endothelial tissue layer developed on the occluded orifice of the left atrium 90 days after implantation. This endothelial layer was not evident on the stapled right atrial appendage. CONCLUSION: In dogs, the third-generation atrial exclusion device achieved easy, reliable, and safe exclusion of the left atrial appendage with favorable histologic results. Clinical application could provide a new therapeutic option for reducing the risk of stroke in patients with atrial fibrillation.

Phasic coronary blood flow patterns in dogs vs. pigs: an acute ischemic heart study.

BACKGROUND: Canine and porcine hearts have been widely used to investigate diagnoses, interventions, and surgical therapies for ischemic heart disease. Dogs and pigs are known to vary with regard to the anatomic distribution of their coronary arteries. However, the mechanisms of these differences and the differing phasic coronary blood flow patterns between the two species are not well characterized. MATERIAL/METHODS: Phasic coronary blood flow patterns and hemodynamic data were analyzed using three flow probes placed around the left anterior descending (LAD), left circumflex (LCX), and right coronary (RCA) arteries in both canine and porcine models. RESULTS: Systolic left ventricular pressure, arterial pressure, and systemic vascular resistance in dogs were higher than in pigs. Likewise, total coronary blood flow, LAD flow, and LCX flow were higher in dogs than in pigs. LCX flow was higher in dogs, but RCA flow was higher in pigs. Diastolic fraction and diastolic/systolic peak velocity ratio of the LAD, LCX, and RCA showed no significant differences at baseline between dogs and pigs. Systolic LAD flow in dogs decreased after the creation of an LAD stenosis, whereas systolic LAD flow in pigs increased. CONCLUSIONS: Coronary blood flow patterns in dogs and pigs are quite different. These findings are potentially relevant to understanding the physiology of myocardial blood perfusion in dogs and pigs with ischemic heart disease.

Reduced pulsatility induces periarteritis in kidney: role of the local renin-angiotensin system.

OBJECTIVE: The need for pulsatility in the circulation during long-term mechanical support has been a subject of debate. We compared histologic changes in calf renal arteries subjected to various degrees of pulsatile circulation in vivo. We addressed the hypothesis that the local renin-angiotensin system may be implicated in these histologic changes. METHODS AND RESULTS: Sixteen calves were implanted with devices giving differing degrees of pulsatile circulation: 6 had a continuous flow left ventricular assist device (LVAD); 6 had a continuous flow right ventricular assist device (RVAD); and 4 had a pulsatile total artificial heart (TAH). Six other calves were histologic and immunohistochemical controls. In the LVAD group, the pulsatility index was significantly lower (0.28 +/- 0.07 LVAD vs 0.56 +/- 0.08 RVAD, vs 0.53 +/- 0.10 TAH; P < 0.01), and we observed severe periarteritis in all cases in the LVAD group. The number of angiotensin II type 1 receptor-positive cells and angiotensin converting enzyme-positive cells in periarterial areas was significantly higher in the LVAD group (angiotensin II type 1 receptor: 350 +/- 139 LVAD vs 8 +/- 6 RVAD, vs 3 +/- 2 TAH, vs 3 +/- 2 control; P < .001; angiotensin-converting enzyme: 325 +/- 59 LVAD vs 6 +/- 4 RVAD, vs 6 +/- 5 TAH, vs 3 +/- 1 control; P < .001). CONCLUSIONS: The reduced pulsatility produced by a continuous flow LVAD implantation induced severe periarteritis in the kidneys. The local renin-angiotensin system was up-regulated in the inflammatory cells only in the continuous flow LVAD group.

Acute reduction of functional mitral regurgitation in canine model using an epicardial device.

PURPOSE: This study evaluated the short-term feasibility of a novel epicardial device that treats functional mitral regurgitation by simultaneously changing the mitral and the left ventricular geometry. DESCRIPTION: We implanted a prototype device that consists of 2 tissue anchors, a deflector, and a flexible tightening chord in 7 mongrel dogs with heart failure and functional mitral regurgitation induced by rapid ventricular pacing. Hemodynamic and echocardiographic data were obtained before and after device implantation. EVALUATION: The device acutely reduced the mitral regurgitation grade from 3.2 +/- 0.3 to 0.9 +/- 0.5 (p < 0.001). Left ventricular end-diastolic volume (79.6 +/- 23.6 to 61.2 +/- 16.9 mL; p = 0.004) and end-systolic volume (63.1 +/- 17.3 to 49.2 +/- 12.3 mL; p = 0.006) decreased substantially. End-systolic elastance significantly increased from 1.9 +/- 1.0 to 2.6 +/- 1.4 mm Hg/mL (p = 0.02). Device implantation did not alter coronary perfusion. CONCLUSIONS: The epicardial device acutely reduced functional mitral regurgitation and improved left ventricular geometry. Further studies are required to demonstrate the long-term safety and efficacy of this concept.

Beating heart cardioscopy: a platform for real-time, intracardiac imaging.

PURPOSE: The purpose of this study was to develop a method for real-time, fiberoptic, intracardiac imaging to serve as a platform for closed-chest, intracardiac surgery on the beating heart. DESCRIPTION: Fiberoptic cardioscopy of the left and right heart was conducted in a porcine model. A cardiopulmonary bypass circuit maintained systemic organ perfusion and a separate circuit replaced intracardiac blood with oxygenated, modified Krebs-Henseleit perfusate. EVALUATION: Video images of structures in the left and right sides of an in vivo beating heart were obtained, including the inner surface of the left and right atria and ventricles, the mitral and aortic valves, the Thebesian veins, and the coronary sinus. Effective isolation of the heart from systemic and intracardiac blood flow and control of perfusion rates were important factors for successful image acquisition. CONCLUSIONS: Fiberoptic cardioscopy is a novel approach that allows for visualization of the structures within a nonarrested heart on bypass. It lays the groundwork for a platform that could lead to more successful percutaneous valvular and intracardiac procedures in a stable hemodynamic environment.

Innovative, replaceable heart valve: concept, in vitro study, and acute in vivo study.

The purpose of this study was to evaluate the feasibility of our innovative, replaceable heart valves that can be easily detached from the sewing ring at the time of repeat replacement. The prototype devices consist of the base magnet ring assembly and the valve magnet ring assembly that utilize magnetic coupling force for the locking mechanism. Magnetic coupling strength was evaluated in vitro. Prototype bioprosthetic valves were implanted acutely in three sheep to confirm the feasibility of the replaceable mitral valve. The static separation force of prototype size #25 was 12.5 lb, meeting the design goal. In situ attachment and detachment of the valve magnet ring assembly from the base magnet ring assembly were very easily accomplished in all animals. The magnetic coupling did not decouple even under extremely high left ventricular pressures. We have demonstrated the feasibility of this innovative concept of a replaceable mitral valve.

Acute in vivo evaluation of an implantable continuous flow biventricular assist system.

An implantable biventricular assist device offers a considerable opportunity to save the lives of patients with combined irreversible right and left ventricular failure. The purpose of this study was to evaluate the hemodynamic and physiologic performance of the combined implantation of the CorAide left ventricular assist device (LVAD) and the DexAide right ventricular assist device (RVAD). Acute hemodynamic responses were evaluated after simulating seven different physiological conditions in two calves. Evaluation was performed by fixing the speed of one individual pump and increasing the speed of the other. Under all conditions, increased LVAD or RVAD speed resulted in increased pump flow. The predominant pathophysiologic effect of independently varying DexAide and CorAide pump speeds was that the left atrial pressure was very sensitive to increasing RVAD speed above 2,400 rpm, whereas the right atrial pressure demonstrated much less sensitivity to increasing LVAD speed. An increase in aortic pressure and RVAD flow was observed while increasing LVAD speed, especially under low contractility, ventricular fibrillation, high pulmonary artery pressure, and low circulatory blood volume conditions. In conclusion, a proper RVAD-LVAD balance should be maintained by avoiding RVAD overdrive. Additional studies will further investigate the performance of these pumps in chronic animal models.