Circulatory Failure Research Articles

Diastolic dysfunction: assessment and implications on the single ventricle circulation.

Patients with a functionally single ventricle (SV) are palliated with a series of procedures leading to a Fontan circulation. Over the life span, a substantial proportion of SV patients develop heart failure that can arise from circulatory or ventricular failure. Diastolic dysfunction (DD) is an important determinant of adverse outcomes in SV patients. However, assessment and categorization of DD in the SV remains elusive. We review recent literature and developments in assessment of DD in the SV and its relation to clinical outcomes. DD is prevalent in the SV and associated with worse outcomes. Occult DD can be exposed with provocative testing by exercise or preload challenge during catheterization. Likewise, sensitivity to detect DD may be increased via assessment of atrial function and strain imaging. Recent studies revisiting previous concepts such as incoordinate diastolic wall motion show that these are associated with SV end-diastolic pressures and post-Fontan recovery, yielding accessible DD assessment. Emerging technologies such as ultrafast ultrasound (UFUS) can provide noninvasive assessment of myocardial stiffness, inefficient diastolic flow patterns and intraventricular pressure gradients, thereby yielding new tools and insights into diastolic myocardial and hemodynamic properties. Characterizing DD in the SV continues to have substantial limitations, necessitating synthesis of multiple parameters into an overall assessment, accounting for their change over time, and in the context of the patient's clinical status. New and emerging techniques may help advance DD assessment and the ability to track response to treatment of new targets.

Patient Reported Outcome Measures in Adults with Fontan Circulatory Failure.

Background: Patient reported outcomes (PROs) are important measures in acquired heart disease but have not been well defined in Adult Congenital Heart Disease (ACHD). Our aim was to explore the discriminatory capacity of PRO survey tools in Fontan circulatory failure (FCF). Methods: Consecutive adults were enrolled from our ambulatory clinics. Inclusion criteria were age ≥18 years, a Fontan circulation or a hemodynamically insignificant shunt lesion, and sufficient cognitive/language abilities to complete PROs. A comprehensive package of PRO measures, designed to assess perceived health-related quality of life (HRQOL) was administered (including the Kansas City Cardiomyopathy Questionnaire [KCCQ-12], EuroQol-5-dimension [EQ5D], Short Form Health Status Survey [SF-12], self-reported New York Heart Association [NYHA] Functional Class, and Specific Activity Scale [SAS]). Results: We compared 54 Fontan patients (35 ± 10 years) to 25 simple shunt lesion patients (34 ± 11 years). The KCCQ-12 score was lower in Fontan versus shunt lesion patients (87 [IQR 79, 95] versus 100 [IQR 97, 100], p-value < 0.001). The FCF subgroup was associated with lower KCCQ-12 scores as compared with the non-FCF subgroup (82 [IQR 56, 89] versus 93 [IQR 81, 98], p-value = 0.002). Although the KCCQ-12 had the best discriminatory capacity for determination of FCF of all PRO tools studied (c-statistic 0.75 [CI 0.62, 0.88]), superior FCF discrimination was achieved when the KCCQ-12 was combined with all PRO tools (c-statistic 0.82 [CI 0.71, 0.93]). Conclusions: The KCCQ-12 questionnaire demonstrated good discriminatory capacity for the identification of FCF, which was further improved through the addition of complementary PRO tools. Further research will establish the value of PRO tools to guide management strategies in ACHD.

Extracorporeal Membrane Oxygenation in Amniotic Fluid Embolism: A Systematic Review of Case Reports.

Amniotic fluid embolism (AFE) is an obstetric complication that can result in acute circulatory failure during and after labor. The effectiveness of extracorporeal membrane oxygenation (ECMO) in AFE patients has not been established, especially in the context of coagulopathy. This review aims to evaluate the efficacy of ECMO support in AFE patients. We conducted a systematic review of case reports following the Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Quality assessment was performed using a standardized tool. Out of 141 studies screened, 33 studies included 79 AFE patients. The median age was 34 years, and the median gestational age was 37.5 weeks. The majority of AFE cases occurred during cesarean section delivery (55.2%), followed by labor before fetal delivery (26.7%). Extracorporeal membrane oxygenation configurations included venoarterial ECMO (81.3%) and extracorporeal cardiopulmonary resuscitation (CPR, 10.7%). The maternal survival rate was 72%, with 21.2% experiencing minor neurological sequelae and 5.8% having major neurological sequelae. Rescue ECMO to support circulation has demonstrated both safety and efficacy in managing AFE. We suggest early activation of local or mobile ECMO as soon as an AFE diagnosis is established. Further studies are needed to assess the benefits and implications of early ECMO support in AFE patients.

Predicting and Measuring Fluid Responsiveness by Hemodynamic Indices versus Transthoracic Echocardiography in Clinically Shocked Patients

Abstract Background In the last decades dynamic measures had evolved as a better solution to predict fluid responsiveness in clinically shocked patients, out of multiple dynamic parameters we chose transthoracic echocardiographic based measurements of variations of aortic blood flow and inferior vena caval diameter. Aim of the Work to assess accuracy of transthoracic echo measured variation in aortic blood flow and inferior vena caval diameter with limited bolus crystalloid infusion in predicting fluid responsiveness in patients with clinical shock. Patients and Methods This study included 51 selected Patients with acute circulatory failure secondary to clinical shock admitted to ICU. All patients had undergone basic transthoracic echocardiographic (TTE) assessment of aortic blood flow (using left ventricular outflow tract velocity time integral as a surrogate) and inferior vena caval diameter changes with respiratory cycle, these measures were obtained at time of diagnosis of shock and repeated after infusion of 300 ml crystalloid fluid bolus (over fifteen minutes). Results Our results had revealed significant difference between responders and non-responders regarding aortic flow variation after fifteen minutes. Conclusion Based on the results obtained in this study, it was proved that transthoracic echocardiography can be used as an accurate method to predict fluid responsiveness in shocked patient with fluid challenge.

Successful Venoarterial Extracorporeal Membrane Oxygenation Treatment in a Pregnant Woman with Amniotic Fluid Embolism

Amniotic fluid embolism (AFE) is a rare, but catastrophic, obstetric complication with a high mortality rate. Moreover, &gt;50% of maternal deaths occur within 1 h of symptom development. Further, it involves a high perinatal mortality rate, with 50% of affected neonates presenting neurological impairments. AFE is characterized by cardiovascular collapse, respiratory failure, and coagulopathy, followed by encephalopathy, multi-organ failure, and fetal distress. Therefore, its treatment strategy includes cardiopulmonary support, massive transfusion, and early cesarean section. However, venoarterial extracorporeal membrane oxygenation (VA-ECMO) has been used in cases with rapid progression of cardiac dysfunction, which has significantly decreased the maternal mortality rate. Therefore, VA-ECMO has been accepted as a useful treatment method for patients with AFE, including cardiac dysfunction. This article describes a case in which a patient with AFE was successfully treated with VA-ECMO and presents a literature review.

The double barrel Impella exchange: A reliable method for uninterrupted mechanical circulatory support

Classic Impella exchange interrupts flow when the old device is pulled into the aorta before advancing the new device across the aortic valve, threatening circulatory collapse and loss of left ventricular access. In “double barrel,” uninterrupted Impella exchange, the new device is placed into the ventricle alongside the old, where flow is first transitioned completely. Of thirty-one consecutive patients undergoing this procedure, none experienced intraoperative cardiac arrest and 96.8% (30/31) had no new aortic insufficiency. One vascular complication ensued following known preoperative iliac injury. One patient suffered nonembolic stroke; another had subarachnoid hemorrhage. Fifty-five percent (17/31) of patients survived, with 22.6% (7/31) recovering, 25.8% (8/31) undergoing transplant, and 6.5% (2/31) transitioning to durable LVAD. Impella-only survival (83.3%, 10/12) was significantly higher than Impella-ECMO survival (36.8%, 7/19) (OR 14.46, 95% CI 1.74-119.93, p=0.01). We conclude “double barrel” technique is reliable in device-dependent cardiogenic shock patients, offering significant advantage and minimal risk.

Evaluation of Electrical Cardiometry to Assess Fluid Responsiveness in Patients with Acute Circulatory Failure: A Comparative Study with Transthoracic Echocardiography.

Acute circulatory failure is commonly encountered in critically ill patients, that requires fluid administration as the first line of treatment. However, only 50% of patients are fluid-responsive. Identification of fluid responders is essential to avoid the harmful effects of overzealous fluid therapy. Electrical cardiometry (EC) is a non-invasive bedside tool and has proven to be as good as transthoracic echocardiography (TTE) to track changes in cardiac output. We aimed to look for an agreement between EC and TTE for tracking changes in cardiac output in adult patients with acute circulatory failure before and after the passive leg-raising maneuver. Prospective comparative study, conducted at a Tertiary Care Teaching Hospital. We recruited 125 patients with acute circulatory failure and found 42.4% (53 out of 125) to be fluid-responsive. The Bland-Altman plot analysis showed a mean difference of 2.08 L/min between EC and TTE, with a precision of 3.8 L/min. The limits of agreement (defined as bias ± 1.96SD), were -1.7 L/min and 5.8 L/min, respectively. The percentage of error between EC and TTE was 56% with acceptable limits of 30%. The percentage error beyond the acceptable limit suggests the non-interchangeability of the two techniques. More studies with larger sample sizes are required to establish the interchangeability of EC with TTE for tracking changes in cardiac output in critically ill patients with acute circulatory failure. Sharma S, Ramachandran R, Rewari V, Trikha A. Evaluation of Electrical Cardiometry to Assess Fluid Responsiveness in Patients with Acute Circulatory Failure: A Comparative Study with Transthoracic Echocardiography. Indian J Crit Care Med 2024;28(7):650-656.

Comparing The Ratio Of Femoral Vein Diameter To Femoral Artery Diameter With Pulse Pressure Variation As A Diagnostic Tool For Fluid Responsiveness In Mechanically Ventilated Patient: A Prospective Observational Study

Background: There is a correlation between CVP and the femoral vein diameter. Therefore, we assessed the accuracy of the measurement using pulse pressure variation in patients on mechanical ventilation by measuring the ratio of femoral vein diameter to femoral artery diameter. Methods: We enrolled 60 patients with circulatory failure who were on mechanical ventilation (MV) in our clinical research. Two groups of patients were randomly assigned: Group (P): Thirty patients were placed on fully regulated mechanical ventilation, momentarily drugged, and paralyzed. At baseline, PPV is computed directly on Nihon Kohden monitors. Group (F): (n = 30), FVD/FAD ratio guided; The FVD/FAD ratio in our target group (F) was evaluated at baseline, The main outcome was the variation in MAP (mm Hg) following a three-hour infusion of liquids. Results: There was a statistically significant difference in mean arterial pressure (MAP) between before and after the patients received their fluids. MAP was 57.13 ± 2.46 before receiving the fluids, but it increased by an average of 20.60, p-value&lt;0.001. Similarly, there was a statistically significant difference in the FVD/FAD ratio before and after the patients received their fluids. The mean FVD/FAD ratio was 0.91 ± 0.13 before receiving the fluids, but after the patients received their fluids, the mean FVD/FAD ratio was 1.27 ± 0.16 after receiving the fluids. Conclusion: The FVA/FAD ratio is a good indicator to assess the volume status of the patient who received fluids for resuscitation but should be confirmed by other parameters in hypovolemic-pre-resuscitated patients. Highlights • Assessement the accuracy of the measurement using pulse pressure variation in patients on mechanical ventilation • The state of blood volume can be determined using both invasive and non-invasive techniques. The FVA/FAD ratio is a good indicator to assess the volume status of the patient who received fluids for resuscitation.

Lipid Emulsions Inhibit Labetalol-Induced Vasodilation in the Isolated Rat Aorta.

Lipid emulsions are used as adjuvant drugs to alleviate intractable cardiovascular collapse induced by drug toxicity. We aimed to examine the effect of lipid emulsions on labetalol-induced vasodilation and the underlying mechanism in the isolated rat aorta. We studied the effects of endothelial denudation, NW-nitro-l-arginine methyl ester (l-NAME), calmidazolium, methylene blue, 1H-[1,2,4]oxadiazolo[4,3-a] quinoxalin-1-one (ODQ), and lipid emulsions on labetalol-induced vasodilation. We also evaluated the effects of lipid emulsions on cyclic guanosine monophosphate (cGMP) formation, endothelial nitric oxide synthase (eNOS) phosphorylation, and endothelial calcium levels induced by labetalol. Labetalol-induced vasodilation was higher in endothelium-intact aortas than that in endothelium-denuded aortas. l-NAME, calmidazolium, methylene blue, and ODQ inhibited labetalol-induced vasodilation in endothelium-intact aortas. Lipid emulsions inhibited labetalol-induced vasodilation in endothelium-intact and endothelium-denuded aortas. l-NAME, ODQ, and lipid emulsions inhibited labetalol-induced cGMP formation in endothelium-intact aortas. Lipid emulsions reversed the stimulatory and inhibitory eNOS (Ser1177 and Thr495) phosphorylation induced by labetalol in human umbilical vein endothelial cells and inhibited the labetalol-induced endothelial calcium increase. Moreover, it decreased labetalol concentration. These results suggest that lipid emulsions inhibit vasodilation induced by toxic doses of labetalol, which is mediated by the inhibition of endothelial nitric oxide release and reduction of labetalol concentration.

Pregnancy and its outcome in antiphospholipid syndrome after acute cerebral circulatory failure (clinical case study)

Pregnancy and its outcome in antiphospholipid syndrome after acute cerebral circulatory failure (clinical case study)

Centhaquine Increases Stroke Volume and Cardiac Output in Patients with Hypovolemic Shock.

Introduction: Centhaquine is a resuscitative agent that acts on α2B adrenergic receptors. Its effect on cardiac output in hypovolemic shock patients has not been reported. Methods: This pilot study was conducted in 12 hypovolemic shock patients treated with centhaquine who participated in an open-label phase IV study (NCT05956418). Echocardiography was utilized to measure stroke volume (SV), cardiac output (CO), left ventricular outflow tract velocity time integral (LVOT-VTI) and diameter (LVOTd), heart rate (HR), left ventricular ejection fraction (LVEF) and fractional shortening (LVFS), and inferior vena cava (IVC) diameter before (0 min) and 60, 120, and 300 min after centhaquine (0.01 mg/kg) iv infusion for 60 min. Results: SV was significantly increased after 60, 120, and 300 min. CO increased significantly after 120 and 300 min despite a decrease in HR. IVC diameter and LVOT-VTI at these time points significantly increased, indicating the increased venous return. LVEF and LVFS did not change, while the mean arterial pressure (MAP, mmHg) increased after 120 and 300 min. Positive correlations between IVC diameter and SV (R2 = 0.9556) and between IVC diameter and MAP (R2 = 0.8928) were observed, which indicated the effects of an increase in venous return on SV, CO, and MAP. Conclusions: Centhaquine-mediated increase in venous return is critical in enhancing SV, CO, and MAP in patients with hypovolemic shock; these changes could be pivotal for reducing shock-mediated circulatory failure, promoting tissue perfusion, and improving patient outcomes. Trial Registration: CTRI/2021/01/030263 and NCT05956418.

Extracorporeal membrane oxygenation states basilar artery thrombectomy and left posterior cerebral artery stent thrombectomy: A case report

BACKGROUND Extracorporeal membrane oxygenation (ECMO) is a new type of extracorporeal respiratory and circulatory assistance device. It can drain venous blood out of the body and inject it into veins or arteries after being oxygenated by an oxygenator (membrane lung) to replace lung and heart functions in a short time. ECMO can provide tissue blood perfusion and gas exchange almost equivalent to cardiac output and extend the effective treatment time window for patients with acute circulatory failure to restore cardiopulmonary function. CASE SUMMARY We report a case of an 81-year-old woman who underwent whole cerebral angiography, basilar artery thrombectomy and stent thrombectomy in the posterior artery of the left brain after implantation of ECMO. The patient was admitted to the hospital due to myocardial infarction. Considering that the cause of the patient’s disturbance of consciousness was unknown and cerebrovascular accident could not be ruled out after the implantation of ECMO, the department of Radioactive Intervention performed cerebral angiography. And the result of the angiography indicated vascular occlusion. After the basilar artery thrombectomy and stent thrombectomy in the posterior artery of the left brain, the patency of the occlusive vessel was achieved. CONCLUSION Although the patient eventually died of circulatory failure, the result of this case verifies the feasibility of cerebral angiography and thrombectomy in patients with implanted ECMO in the intubated state.

Effect of lipid emulsion on vasoconstriction induced by epinephrine or norepinephrine in isolated rat aorta.

Epinephrine (EPI) or norepinephrine (NOR) is widely used to treat cardiovascular collapse during lipid emulsion (LE) resuscitation for drug toxicity. However, the effect of LE on the vasoconstriction caused by EPI or NOR remains unknown. The purpose of this study was to examine the effect of an LE (Intralipid) on the vasoconstriction caused by EPI and NOR in isolated rat aorta. The effect of LE on the vasoconstriction caused by EPI or NOR in isolated rat aorta was examined. Additionally, the effect of LE on the calcium increase caused by EPI or NOR was investigated. The distribution constant (KD: lipid to aqueous phase) of EPI or NOR between a LE (1%) and an aqueous phase was determined. LE (1 and 2%) did not significantly alter vasoconstriction caused by EPI or NOR in isolated endothelium-intact aorta. Moreover, the LE did not significantly alter the increased calcium level caused by EPI or NOR. The log KD of EPI in the LE (1%) was -0.71, -0.99, and -1.00 at 20, 50, and 100 mM ionic strength, respectively. The log KD of NOR in the LE (1%) was -1.22, -1.25, and -0.96 at 20, 50, and 100 mM ionic strength, respectively. Taken together, the Intralipid emulsion did not alter vasoconstriction induced by EPI or NOR that seems to be due to the hydrophilicity of EPI or NOR, leading to sustained hemodynamic support produced by EPI or NOR used during LE resuscitation.

Vitamin D deficiency and secondary hyperparathyroidism in adult Fontan patients

BackgroundThe prevalence of vitamin D deficiency and secondary hyperparathyroidism (sHPT) in adult Fontan patients remains unstudied, and the role of vitamin D and parathyroid hormone (PTH) levels in assessing heart and circulatory failure in these patients is unclear. MethodsWe compared vitamin D deficiency and sHPT prevalence in adult Fontan patients (n = 35; mean age 33 ± 7.5 years) to adults with mild congenital heart disease (ACHD, n = 14). We analyzed associations between laboratory measurements, patient characteristics, and clinical events. FindingsVitamin D deficiency was highly prevalent in both Fontan patients and ACHD controls (76.5 % vs. 71.4 %, p = 0.726). sHPT was exclusively present in Fontan patients (31.4 %). PTH levels correlated with NYHA class (r = 0.412), O2 saturation (r = −0.39), systemic ventricular function (r = 0.465), and NT-proBNP levels (r = 0.742). 25-hydroxyvitamin D showed an inverse correlation with NYHA class and systemic ventricular function (both r ≤ −0.38). Fontan patients with sHPT had a higher incidence of prior hospitalization for worsening heart failure and atrial arrhythmias compared to Fontan patients without HPT or ACHD controls. (Hospitalization: Fontan with HPT vs. Fontan without HPT: OR 5.46 [95 % CI 1.25–23.86], p = 0.021; arrhythmia: Fontan with HPT vs. Fontan without HPT: OR 1.96 [95 % CI 1.13–3.4], p = 0.035; ACHD: OR 11.45 [95 % CI 1.7–77.28], p=<0.001). PTH showed significant correlation with inflammatory markers, particularly with GDF-15 (r = 0.8). ConclusionOur study is the first to demonstrate a high prevalence of vitamin D deficiency and sHPT in adult Fontan patients. As PTH strongly correlates with heart failure severity, it seems to be a promising biomarker in Fontan patients.

Study of the cement implantation syndrome: A review.

Bone cement implantation syndrome (BCIS) is a critical and potentially life-threatening condition that manifests during implantation. Characterized by a constellation of symptoms, including hypoxemia, hypotension, cardiac arrhythmias, elevated pulmonary vascular resistance, and occasionally cardiac arrest, BCIS typically ensues shortly after cement introduction, albeit with rare instances of delayed onset. Primarily attributed to the exothermic reaction of bone cement implantation, this syndrome is caused by local tissue damage, histamine and prostaglandin release, and microemboli formation, ultimately triggering a systemic immune response that culminates in respiratory and circulatory failure. The current hypotheses regarding BCIS include embolism, allergic reactions, and cement autotoxicity. BCIS management emphasizes preventative strategies, encompassing meticulous patient risk assessment, comprehensive preoperative and intraoperative evaluations, and precise cement application techniques. Treatment primarily involves symptomatic therapy and life-support measures to address the systemic effects of the syndrome.

The Efficacy of Whole Blood Resuscitation During Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) to Mitigate Post-occlusion Circulatory Collapse: A Translational Model in Large Swine.

Uncontrolled torso hemorrhage is the primary cause of potentially survivable deaths on the battlefield. Zone 1 Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA), in conjunction with damage control resuscitation, may be an effective management strategy for these patients in the prehospital or austere phase of their care. However, the effect of whole blood (WB) transfusion during REBOA on post-occlusion circulatory collapse is not fully understood. Yorkshire male swine (n = 6 per group, 70-90 kg) underwent a 40% volume-controlled hemorrhage. After a 10-minute hemorrhagic shock period, a REBOA balloon was inflated in Zone 1. Fifteen minutes after inflation, 0, 1, or 3 units (450 mL/unit) of autologous WB was infused through the left jugular vein. Thirty minutes after initial balloon inflation, the balloon was deflated slowly over 3 minutes. Following deflation, normal saline was administered (up to 3,000 mL) and swine were observed for 2 hours. Survival (primary outcome), hemodynamics, and blood gas values were compared among groups. Statistical significance was determined by log-rank test, one-way ANOVA, and repeated measures ANOVA. Survival rates were comparable between groups (P = .345) with 66% of control, 33% of the one-unit animals, and 50% of the 3-unit animals survived until the end of the study. Following WB infusion, both the 1-unit and the 3-unit groups had significantly higher blood pressure (P < .01), pulmonary artery pressure (P < .01), and carotid artery flow (P < .01) compared to the control group. WB transfusion during Zone 1 REBOA was not associated with increased short-term survival in this large animal model of severe hemorrhage. We observed no signal that WB transfusion may mitigate post-occlusion circulatory collapse. However, there was evidence of supra-normal blood pressures during WB transfusion.

Remimazolam anaphylaxis in a patient not allergic to brotizolam: a case report and literature review

BackgroundRemimazolam is a recently developed, ultrashort-acting benzodiazepine that is used as a general anesthetic. Some cases of remimazolam anaphylaxis have been reported, but its characteristics are not fully understood. We present an interesting case report and review of the literature to better understand remimazolam anaphylaxis.Case presentationA 75-year-old man scheduled for robot-assisted gastrectomy was administered remimazolam for the induction of general anesthesia. After intubation, low end-expiratory CO2, high airway pressure and concurrent circulatory collapse were observed. Bronchoscopy revealed marked tracheal and bronchial edema, which we diagnosed as anaphylaxis. The patient suffered cardiac arrest after bronchoscopy but recovered immediately with intravenous adrenaline administration and chest compressions. We performed skin prick tests for the drugs used during induction except for remimazolam, considering the high risk of systemic adverse reactions to remimazolam. We diagnosed remimazolam anaphylaxis because the skin prick test results for the other drugs used during anesthesia were negative, and these drugs could have been used without allergic reactions during the subsequent surgery. Furthermore, this patient had experienced severe anaphylactic-like reactions when he underwent cardiac surgery a year earlier, in which midazolam had been used, but it was not thought to be the allergen at that time. Based on these findings, cross-reactivity to remimazolam and midazolam was suspected. However, the patient had previously received another benzodiazepine, brotizolam, to which he was not allergic, suggesting that cross-reactivity of remimazolam may vary among benzodiazepines. In this article, we reviewed the 11 cases of remimazolam anaphylaxis that have been described in the literature.ConclusionsRemimazolam is an ultrashort-acting sedative; however, it can cause life-threatening anaphylaxis. In addition, its cross-reactivity with other benzodiazepines is not fully understood. To increase the safety of this drug, further research and more experience in its use are needed.

Changes in echocardiographic indices and left ventricular strain values by two-dimensional speckle-tracking echocardiography following pre-anesthetic oral pimobendan administration compared with intravenous pimobendan in dogs.

The effects of pre-anesthetic single-dose oral pimobendan during inhalational anesthesia, including the comparison with the effects of single intravenous pimobendan under anesthesia, remain unexplored. Therefore, this study aimed to determine changes in hemodynamic and echocardiographic parameters induced by pre-anesthetic administration of oral pimobendan under isoflurane general anesthesia and to compare them with those induced by intravenous pimobendan. Thirteen clinically normal dogs (4 laboratory and 9 client-owned dogs) with no clinical signs and not on any medical treatment were included. Anesthesia was performed three times: no pimobendan (Control), oral pimobendan (PIMO PO, 0.3 mg/kg), and intravenous pimobendan (PIMO IV, 0.15 mg/kg). Echocardiographic and hemodynamic parameters were monitored at 30-min intervals in all groups. Compared to the Control group, end-systolic volume index (ESVI) and normalized left ventricular internal diameter at end-systole (LVIDSN) were significantly lower, and fractional shortening (FS) and ejection fraction (EF) were significantly higher in the PIMO PO and IV groups (p < 0.001). Global radial strain (GRS) was significantly higher in the PIMO PO and IV groups (p = 0.015). Under general anesthesia, oral pimobendan preserved LV systolic and myocardial function in a manner comparable to intravenous pimobendan. Pre-anesthetic administration of oral pimobendan can be used to compensate for cardiac systolic function in dogs who require therapeutic and diagnostic procedures under general anesthesia with potential risk of circulatory failure.

Perioperative strategies and management of giant anterior mediastinal tumors: a narrative review.

Giant anterior mediastinal tumors sometimes may cause circulatory collapse and respiratory failure, known as mediastinal mass syndrome (MMS). The prediction and prevention of MMS is challenging. The aim of this study is to summarize the evaluation methods for MMS and formulate treatment strategies for giant anterior mediastinal tumors. We performed a thorough analysis of recent international literature on giant anterior mediastinal tumors (>10 cm in diameter) and MMS published in the PubMed database. The search spanned the duration of the preceding 10 years from August 19, 2023, and only studies published in English were included. Mature teratomas and liposarcomas are the most common giant anterior mediastinal tumors and MMS develops most frequently in case of malignant lymphomas. Here, we propose a new treatment strategy for giant anterior mediastinal tumors. Based on imaging findings, giant anterior mediastinal tumors can be classified as cystic or solid and further blood investigation data are useful for a definitive diagnosis. When malignant lymphoma or malignant germ cell tumor is highly suspected, the first choice of treatment is not surgery but chemotherapy and radiotherapy. Moreover, image-guided drainage may be effective if giant cystic anterior tumors develop into MMS. The risk classification of MMS is important for treating giant anterior mediastinal tumors. If the MMS risk classification is 'unsafe' or 'uncertain', the intraoperative management deserves special attention. The surgical approach should however be based on tumor localization and invasion of surrounding tissues. Multidisciplinary team coordination is indispensable in the treatment of giant anterior mediastinal tumors. When giant anterior mediastinal tumors are encountered, it is important to follow the appropriate treatment strategy, focusing on the development of MMS based on imaging findings and symptoms.

Outcomes of extracardiac Fontan operation: A single institution experience with 398 patients

ObjectiveThe study objective was to evaluate the outcomes of the extracardiac Fontan operation at a single institution. MethodsWe conducted a retrospective study of 398 patients from a single institution who underwent their initial extracardiac Fontan operation between 1997 and 2020. We determined the incidence of and risk factors for failure of the Fontan circulation, which includes death, Fontan takedown, heart transplantation, protein-losing enteropathy, plastic bronchitis, and functional status at the last follow-up. ResultsThe median follow-up time was 10.3 years (interquartile range, 6.4-14.6). The overall survival was 96% and 86% at 10 and 20 years after extracardiac Fontan operation, respectively. There were 6 early deaths (6/398, 1.5%) and 15 late deaths (15/398, 3.8%). Forty-nine patients (12.5%) developed failure of the Fontan circulation. Freedom from the failure of Fontan circulation was 88% at 10 years and 76% at 20 years. Risk factors for failure of the Fontan circulation were right ventricular dominance (hazard ratio, 4.7; P < .001; 95% CI, 2.1-10.5), aortic atresia (hazard ratio, 5.5; P < .001; 95% CI, 2.3-12.8), and elevated mean pulmonary artery pressure (hazard ratio, 2.3; P = .002; 95% CI, 1.2-6.7). ConclusionsRates of failure of the Fontan circulation are low after the contemporary extracardiac Fontan operation. Risk factors for failure of the extracardiac Fontan circulation include right ventricular dominance, aortic atresia, and elevated pulmonary artery pressures.