Andrew Roscoe

Echocardiography for adult patients supported with extracorporeal membrane oxygenation

Venoarterial (VA) and venovenous (VV) extracorporeal membrane oxygenation (ECMO) support is increasingly being used in recent years in the adult population. Owing to the underlying disease precipitating severe respiratory or cardiac failure, echocardiography plays an important role in the management of these patients. Nevertheless, there are currently no guidelines on the use of echocardiography in the setting of ECMO support. This review describes the current state of application of echocardiography for patients supported with both VA and VV ECMO.

Pressures exerted by endobronchial devices.

BACKGROUND:High endotracheal cuff pressures have been shown to cause high mucosal pressures and a reduction in mucosal blood flow, with the risk of mucosal ischemia. We aimed to directly measure the pressure exerted by the bronchial cuffs of double-lumen tubes (DLT) and by the cuffs of three new designs of endobronchial blocker (EBB). METHODS:Using a validated in vitro model and a previously described technique, we measured the static pressures exerted by the cuff of DLTs and EBBs with 1 mL increments in cuff volume until maximum inflation was achieved. The study was repeated under dynamic conditions of simulated positive pressure ventilation. RESULTS:The pressures exerted by the cuffs of DLTs ranged from 16–155 mm Hg. Pressures exerted by the EBB cuffs ranged from 39–194 mm Hg. At intra-cuff volumes required to create a seal to 25 cm H2O positive pressure, the pressures exerted by the cuffs of all the devices were <30 mm Hg. CONCLUSIONS:A transmitted pressure <30 mm Hg has been recommended to avoid mucosal injury. Our study shows that at clinically relevant cuff volumes, the pressures exerted by the cuffs do not exceed the recommended safe limit.

The Right Ventricle in ARDS

&NA; ARDS is associated with poor clinical outcomes, with a pooled mortality rate of approximately 40% despite best standards of care. Current therapeutic strategies are based on improving oxygenation and pulmonary compliance while minimizing ventilator‐induced lung injury. It has been demonstrated that relative hypoxemia can be well tolerated, and improvements in oxygenation do not necessarily translate into survival benefit. Cardiac failure, in particular right ventricular dysfunction (RVD), is commonly encountered in moderate to severe ARDS and is reported to be one of the major determinants of mortality. The prevalence rate of echocardiographically evident RVD in ARDS varies across studies, ranging from 22% to 50%. Although there is no definitive causal relationship between RVD and mortality, severe RVD is associated with increased mortality. Factors that can adversely affect RV function include hypoxic pulmonary vasoconstriction, hypercapnia, and invasive ventilation with high driving pressure. It might be expected that early diagnosis of RVD would be of benefit; however, echocardiographic markers (qualitative and quantitative) used to prospectively evaluate the right ventricle in ARDS have not been tested in adequately powered studies. In this review, we examine the prognostic implications and pathophysiology of RVD in ARDS and discuss available diagnostic modalities and treatment options. We aim to identify gaps in knowledge and directions for future research that could potentially improve clinical outcomes in this patient population.

The Use of Prothrombin Complex Concentrates in Two Patients With Non-Pulsatile Left Ventricular Assist Devices

From the Department of Anesthesia & Pain Management, Toronto General Hospital, Toronto, Ontario, Canada. Address reprint requests to Lindsay Hurlburt, MD, Department of Anesthesia & Pain Management, Toronto General Hospital, 200 Elizabeth Street, Toronto M5G 2C4 Canada. E-mail: lindsay. hurlburt@medportal.ca & 2014 Elsevier Inc. All rights reserved. 1053-0770/2602-0033

Evaluation of the Clinical Utility of Transesophageal Echocardiography and Invasive Monitoring to Assess Right Ventricular Function During and After Pulmonary Endarterectomy

36.00/0 http://dx.doi.org/10.1053/j.jvca.2013.02.011

Atrioventricular disruption after mitral valve replacement: the role of intraoperative transesophageal echocardiography.

OBJECTIVE Patients undergoing pulmonary endarterectomy (PEA) have impaired right ventricular function. The authors sought to assess the clinical utility of commonly used perioperative echocardiographic and right heart catheter measurements in patients undergoing PEA. DESIGN A single-center prospective observational study. SETTING The study was conducted in a quaternary care cardiac surgical center in the United Kingdom. PARTICIPANTS Patients undergoing PEA between April 2015 and January 2016. INTERVENTIONS Thermodilution cardiac index and echocardiography variables were measured at 3 time points: before sternotomy (T1), after pericardial incision (T2), and after sternal closure (T3). Six-month follow-up echocardiography and 6-minute walk (6-MWT) test were performed. MEASUREMENTS AND MAIN RESULTS Fifty patients were recruited and complete data sets were available for 41 patients. Tricuspid annular plane systolic excursion declined after pericardial incision and cardiopulmonary bypass (T1: 15 ± 4 mm, T2: 13 ± 4 mm, T3: 7 ± 2 mm; p < 0.0001), returning to baseline 6 months postoperatively. Cardiac index (T1: 2.5 ± 0.7 L/min/m2, T2: 2.6 ± 0.6 L/min/m2, T3: 2.3 ± 0.5 L/min/m2; p = 0.07) and right ventricular fractional area change (T1: 36 ± 11%, T2: 40 ± 12%, T3: 40 ± 9%; p = 0.12) were preserved perioperatively. 6-MWT improved from baseline (294 ± 111 m) to follow-up (357 ± 107 m) (p < 0.001). Pulmonary vascular resistance at T3 correlated moderately with follow-up 6-MWT (R = -0.60). CONCLUSIONS In patients undergoing PEA, invasive measurements and echocardiography assessment of right ventricular function are not interchangeable. Tricuspid annular plane systolic excursion is not a reliable measure of right ventricular function perioperatively. Pulmonary vascular resistance shows moderate correlation with postoperative functional capacity.

Three Cases of Anaphylaxis to Protamine: Management of Anticoagulation Reversal

November 2014 • Volume 119 • Number 5 An 81-year-old man with coronary artery disease and severe mitral regurgitation from myxomatous mitral valve disease was referred for surgery due to progressive congestive heart failure. He was scheduled to have mitral valve replacement (MVR) and coronary artery bypass grafting. His intraoperative transesophageal echocardiogram (TEE) revealed that the main mechanism of his mitral regurgitation was anterior leaflet prolapse. He had severe left ventricular (LV) dysfunction (ejection fraction 25%). There was right ventricular and tricuspid annular dilation with mild-tomoderate tricuspid regurgitation, but right ventricular function was preserved. After completion of the MVR (29 mm Hancock II, Medtronic, Mississauga, Canada) and coronary artery bypass grafting (4 grafts), the patient was weaned from cardiopulmonary bypass (CPB) with inotropic support. Immediate post-CPB TEE revealed paravalvular leak, a small hematoma in the interatrial septum (IAS) and global LV hypokinesia (ejection fraction 10%–20%) (Fig. 1; Video 1, Supplemental Digital Content 1, http://links.lww.com/AA/ A917). The initial diagnosis was myocardial ischemia due to coronary air. The surgeon decided to decannulate the aorta, and protamine was administered. The patient became more hypotensive, despite increasing inotropic requirements. The TEE showed worsening biventricular function, subtle rocking of the bioprosthetic MVR, and hematoma in the IAS (Fig. 2; Video 2, Supplemental Digital Content 2, http://links.lww. com/AA/A918). The patient remained hypotensive, and CPB was reinstituted for surgical exploration. A large hematoma was found in the posterior atrioventricular groove extending to the inferior vena cava. The surgeon attempted but failed to repair the disrupted atrioventricular groove, and the patient died on the operating table. Retrospective analysis of the intraoperative 3-D TEE imaging using Qlab software (Philips Medical Systems) revealed a crescentic gap around the posterior aspect of the MVR, consistent with atrioventricular separation (Fig. 3; Video 3, Supplemental Digital Content 3, http://links.lww.com/AA/A919). With the use of multiple 2D planes (MPR mode) reconstructed from a 3D data set, the extent of atrioventricular separation was more readily appreciated (Fig. 3). Atrioventricular disruption is a rare but fatal complication after MVR, with a reported incidence between 0.5% and 14% and mortality between 50% and 75%.1,2 Classification has been divided into 3 types based on the location of the tear. Type I is the most common type and is associated with MVR. Types II and III have been virtually abolished, primarily due to the introduction of surgical preservation techniques and low-profile mitral prostheses (Table 1). The main clinical presentation for atrioventricular disruption is either unstable hemodynamics after weaning from CPB or failure to wean from CPB. Frank rupture with massive bleeding from the LV can alert the clinicians to the diagnosis of LV rupture. However, LV failure and ventricular arrhythmias are usually nonspecific presentations in many cases. More specific signs, such as dissecting hematoma in the posterior atrioventricular groove, are often not

Contemporary Reviews in Critical Care MedicineThe Right Ventricle in ARDS

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The Right Ventricle in Acute Respiratory Distress Syndrome

&NA; ARDS is associated with poor clinical outcomes, with a pooled mortality rate of approximately 40% despite best standards of care. Current therapeutic strategies are based on improving oxygenation and pulmonary compliance while minimizing ventilator‐induced lung injury. It has been demonstrated that relative hypoxemia can be well tolerated, and improvements in oxygenation do not necessarily translate into survival benefit. Cardiac failure, in particular right ventricular dysfunction (RVD), is commonly encountered in moderate to severe ARDS and is reported to be one of the major determinants of mortality. The prevalence rate of echocardiographically evident RVD in ARDS varies across studies, ranging from 22% to 50%. Although there is no definitive causal relationship between RVD and mortality, severe RVD is associated with increased mortality. Factors that can adversely affect RV function include hypoxic pulmonary vasoconstriction, hypercapnia, and invasive ventilation with high driving pressure. It might be expected that early diagnosis of RVD would be of benefit; however, echocardiographic markers (qualitative and quantitative) used to prospectively evaluate the right ventricle in ARDS have not been tested in adequately powered studies. In this review, we examine the prognostic implications and pathophysiology of RVD in ARDS and discuss available diagnostic modalities and treatment options. We aim to identify gaps in knowledge and directions for future research that could potentially improve clinical outcomes in this patient population.

Erratum to: Echocardiography for adult patients supported with extracorporeal membrane oxygenation

&NA; ARDS is associated with poor clinical outcomes, with a pooled mortality rate of approximately 40% despite best standards of care. Current therapeutic strategies are based on improving oxygenation and pulmonary compliance while minimizing ventilator‐induced lung injury. It has been demonstrated that relative hypoxemia can be well tolerated, and improvements in oxygenation do not necessarily translate into survival benefit. Cardiac failure, in particular right ventricular dysfunction (RVD), is commonly encountered in moderate to severe ARDS and is reported to be one of the major determinants of mortality. The prevalence rate of echocardiographically evident RVD in ARDS varies across studies, ranging from 22% to 50%. Although there is no definitive causal relationship between RVD and mortality, severe RVD is associated with increased mortality. Factors that can adversely affect RV function include hypoxic pulmonary vasoconstriction, hypercapnia, and invasive ventilation with high driving pressure. It might be expected that early diagnosis of RVD would be of benefit; however, echocardiographic markers (qualitative and quantitative) used to prospectively evaluate the right ventricle in ARDS have not been tested in adequately powered studies. In this review, we examine the prognostic implications and pathophysiology of RVD in ARDS and discuss available diagnostic modalities and treatment options. We aim to identify gaps in knowledge and directions for future research that could potentially improve clinical outcomes in this patient population.