The Right Ventricle During Selective Lung Ventilation for Thoracic Surgery

Possible role of QRS duration in the right ventricle as a perioperative monitoring parameter for right ventricular function: a prospective cohort analysis in robotic mitral valve surgery

Background

The clinical importance of the right ventricle (RV) has recently been recognized; however, assessing its function during cardiac surgery remains challenging owing to its complex anatomy. A temporary transvenous pacing catheter is a useful tool in the small surgical field of minimally invasive cardiac surgery, and an electrocardiogram recorded through the catheter is composed of the direct electrophysiological activity of the RV. Therefore, we hypothesized that QRS duration in the RV (QRSRV) could be a useful monitoring parameter for perioperative RV function.

Methods

We conducted a prospective cohort analysis involving adult patients undergoing robotic mitral valve repair. A bipolar pacing catheter was inserted using x-ray fluoroscopy, and the QRSRV duration was assessed at four time points: preoperative baseline, during one-lung ventilation, after weaning from cardiopulmonary bypass, and before the end of surgery. At the same time points, right ventricular fractional area change (RVFAC) measured by transesophageal echocardiography and QRS duration at V5 lead of the body surface electrocardiogram (QRSV5) were also evaluated.

Results

In the 94 patients analyzed, QRSRV duration was significantly prolonged during robotic mitral valve repair (p = 0.0009), whereas no significant intraoperative changes in RVFAC were observed (p = 0.2). By contrast, QRSV5 duration was significantly shortened during surgery (p < 0.00001). Multilinear regression showed a significant correlation of QRSRV duration with RVFAC (p = 0.00006), but not with central venous pressure (p = 0.9), or left ventricular ejection fraction (p = 0.3). When patients were divided into two groups by postoperative QRSRV > 100 or ≤100 ms, 25 patients (26.6%) exhibited the prolonged QRSRV duration, and the mean increase in the postoperative QRSRV from preoperative baseline was 12 ms (p = 0.001), which was only 0.6 ms in patients with QRSRV ≤ 100 ms (p = 0.6). Cox regression analysis showed that prolonged postoperative QRSRV duration was the only significant parameter associated with a longer ICU stay after surgery (p = 0.02; hazard ratio, 0.55).

Conclusion

Our data suggest that QRSRV duration is a useful parameter for monitoring the RV during cardiac surgery, possibly better than a commonly used echocardiographic parameter, RVFAC. An electrophysiological assessment by QRSRV duration could be a practical tool for the complex anatomy of the RV, especially with limited modalities in perioperative settings.

Anesthetic management of children with medically refractory pulmonary hypertension undergoing surgical Potts shunt

INTRODUCTION

Pulmonary hypertension in children is associated with high rates of adverse events under anesthesia. In children who have failed medical therapy, a posttricuspid shunt such as a Potts shunt can offload the right ventricle and possibly delay or replace the need for lung transplantation. Intraoperative management of this procedure, during which an anastomosis between the pulmonary artery and the descending aorta is created, is complex and requires a deep understanding of the pathophysiology of acute and chronic right ventricular failure. This retrospective case review describes the intraoperative management of children undergoing surgical creation of a Potts shunt at a single center.

METHODS

A retrospective case review of all patients under the age of 18 who underwent Potts shunt between April 2013 and June 2022. Medical records were examined, and clinical data of demographics, intraoperative vital signs, anesthetic management, and postoperative outcomes were extracted.

RESULTS

Twenty-nine children with medically refractory pulmonary hypertension underwent surgical Potts shunts with a median age of 12 years (range 4 months to 17.4 years). Nineteen Potts shunts (65%) were placed via thoracotomy and 10 (35%) were placed via median sternotomy with use of cardiopulmonary bypass. Ketamine was the most frequently utilized induction agent (17 out of 29, 59%), and the majority of patients were initiated on vasopressin prior to intubation (20 out of 29, 69%). Additional inotropic support with epinephrine (45%), milrinone (28%), norepinephrine (17%), and dobutamine (14%) was used prior to shunt placement. Following opening of the Potts shunt, hemodynamic support was continued with vasopressin (66%), epinephrine (62%), milrinone (59%), dobutamine (14%), and norepinephrine (10%). Major intraoperative complications included severe hypoxemia (21 out of 29, 72%) and hypotension requiring boluses of epinephrine (10 out of 29, 34.5%) but no patient suffered intraoperative cardiac arrest. There were four in-hospital mortalities.

DISCUSSION

A Potts shunt offers another palliative option for children with medically refractory pulmonary hypertension. General anesthesia in these children carries high risk for pulmonary hypertensive crises. Anesthesiologists must understand underlying physiological mechanisms responsble for acute hemodynaic decompensation during acute pulmonary hypertneisve crises. Severe physiological perturbations imposed by thoracic surgery and use of cardiopulmonay bypass can be mitigated by aggresive heodynamic support of ventricle function and maintainence of systemic vascular resistance. Early use of vasopressin, before or immidiately after anesthesia induction, in combination with other inotropes is a useful agent during the perioperative care of thes. Early use of vasopressin during anesthesia induction, and aggressive inotropic support of right ventricular function can help mitigate effects of induction and intubation, single-lung ventilation, and cardiopulmonary bypass.

CONCLUSIONS

Our single center expereince shows that the Potts shunt surgery, despite high short-term mortaility, may offer another option for palliation in children with medically refractory pulmonary hypertension.

Anesthetic Management During Lung Transplantation - What's New in 2021?

As outcomes of lung transplantation (LTx) are improving transplant centers are pushing boundaries. There has been a steady increase in the medical complexity of lung transplant candidates. Many transplant centers are listing older patients with comorbidities, and there has been a steady rise in the number of candidates supported with extracorporeal membrane oxygenation (ECMO) as a bridge to transplantation. There has been a growing appreciation of the importance intraoperative management of potentially modifiable risk factors has on postoperative outcomes. Evidence suggests that LTx even in high-risk patients requiring perioperative ECMO can offer excellent results. This article outlines the current state-of-the-art intraoperative management of LTx.

Effect of Levosimendan on Acute Decompensated Right Heart Failure in Patients With Connective Tissue Disease-Associated Pulmonary Arterial Hypertension

Aims

Acute decompensated right heart failure (RHF) in chronic precapillary pulmonary hypertension is often typified by a swiftly progressive syndrome involving systemic congestion. This results from the impairment of the right ventricular filling and/or a reduction in the flow output of the right ventricle, which has been linked to a dismal prognosis of short duration. Despite this, there are limited therapeutic data regarding these acute incidents. This study examined the effect of levosimendan on acute decompensated RHF in patients with connective tissue disease-associated pulmonary arterial hypertension (CTD-PAH).

Methods

This retrospective study included 87 patients with confirmed CTD-PAH complicated acute decompensated RHF between November 2015 and April 2021. We collected biological, clinical, and demographic data, as well as therapy data, from patients with acute decompensated RHF who required levosimendan treatment in the cardiac care unit (CCU) for CTD-PAH. The patients were divided into two groups according to the levosimendan treatment. Patient information between the two groups was systematically compared in hospital and at follow-up.

Results

Oxygen saturation of mixed venose blood (SvO₂), estimated glomerular filtration rate (eGFR), 24-h urine output, and tricuspid annular plane systolic excursion (TAPSE) were found to be considerably elevated in the levosimendan cohort compared with the control cohort. Patients in the levosimendan cohort exhibited considerably reduced levels of C-reactive protein (CRP), white blood cell (WBC), troponin I, creatinine, NT-proBNP, and RV diameter compared with those in the control cohort. A higher survival rate was observed in the levosimendan cohort.

Conclusions

Levosimendan treatment could effectively improve acute decompensated RHF and systemic hemodynamics in CTD-PAH patients, with positive effects on survival in hospital and can, therefore, be considered as an alternative treatment option for improving clinical short-term outcomes.

Intraoperative support during lung transplantation

The role of intraoperative mechanical support during lung transplantation (LTx) is essential to provide a safe hemodynamic and ventilatory status during critical intraoperative events. This hemodynamic and ventilatory stability is vital to minimize the odds of suboptimal outcomes, especially considering that, due to the scarcity of donors and the fact that more and more patients with significant comorbidities are being considered for this therapy, a more aggressive approach is often needed by the transplant centers. Hence, the attenuation of any potential injury that can happen during this complex event is paramount. While a thorough assessment of the donor and optimization of postoperative care is pursued, certainly protective intraoperative management would also contribute to better outcomes. Understanding each patient’s underlying anatomy and cardiopulmonary physiology, associated with awareness of critical events during a complicated procedure like LTx, is essential for a precise indication and safe use of support. Cardiopulmonary bypass (CPB) and veno-arterial extracorporeal membrane oxygenation (VA ECMO) have been the most common approaches used, with the latter gaining popularity more recently and we have used VA ECMO exclusively for the last decade. New technologies certainly contributed to more liberal use of VA ECMO intraoperatively, enabling a protecting and physiologic environment for the newly implanted grafts. In this setting, potential prophylactic use for lung protection during a critical period is also considered.

Interleukin-6 level is an independent predictor of right ventricular systolic dysfunction in patients hospitalized with COVID-19

OBJECTIVE

Cytokine storm with elevated levels of multiple proinflammatory cytokines and inflammatory system activation underlie the pathogenesis of coronavirus disease 2019 (COVID-19). In this study, we aimed to investigate whether increased interleukin (IL)-6 levels can predict right ventricular (RV) systolic impairment in patients hospitalized with COVID-19.

METHODS

This prospective, observational study included 100 consecutive patients hospitalized with mild and moderate COVID-19. All the patients underwent chest computerized tomography, detailed laboratory tests including IL-6, and two dimensional (2D) transthoracic echocardiography (TTE) with assessment of 2D conventional and Doppler echocardiography parameters and RV systolic functions.

RESULTS

After the elimination of six patients with exclusion criteria, the remaining patients were classified into two groups, namely normal RV systolic functions (n=60) and impaired RV systolic functions (n=34). IL-6 levels were significantly higher in patients with impaired RV systolic functions than in those with normal RV systolic functions (20.3, 4.6, p<0.001, respectively). Tricuspid annular plane systolic excursion and RV derived tissue Doppler imaging (TDI) S' measurements were similar between the two groups. RV fractional area change was significantly lower, and RV TDI derived index of myocardial performance was significantly higher in patients with impaired RV systolic functions. In multivariate analysis, IL-6 levels independently predicted deterioration in RV systolic function at a significant level (odds ratio: 1.12, 95% confidence interval: 1.04-1.20, p=0.003).

CONCLUSION

IL-6 is an independent predictor of RV systolic impairment in patients hospitalized with mild and moderate COVID-19 suggesting a possible pathogenetic mechanism. IL-6 levels can be used to predict RV systolic impairment in patients suffering from this infection.

Intraoperative Anesthetic Management of the Thoracic Patient

The intraoperative anesthetic management for thoracic surgery can impact a patient's postoperative course, especially in patients with significant lung disease. One-lung ventilation poses an inherent risk to patients, including hypoxemia, acute lung injury, and right ventricular dysfunction. Patient-specific ventilator management strategies during one-lung ventilation can reduce postoperative morbidity.

Right Ventricular Systolic Assessment by Transesophageal Versus Transthoracic Echocardiography: Displacement, Velocity, and Myocardial Deformation

OBJECTIVE

First, to compare tricuspid annular displacement and velocity in transthoracic and transesophageal echocardiography (TTE, TEE) using conventional angle-dependent technologies. Second, to evaluate both alternative TEE views as well as an alternative technology (speckle tracking) for overcoming proposed differences in TTE and TEE.

DESIGN

Prospective, comparative, cross-over study with a randomized order of image acquisition.

SETTING

University hospital.

PARTICIPANTS

Adults undergoing cardiac surgery.

INTERVENTIONS

Postinduction standardized image acquisition and analysis in TTE and TEE by 2 echocardiographers.

MEASUREMENTS AND MAIN RESULTS

The authors measured tricuspid annular plane systolic excursion (TAPSE) by M-mode and velocity by tissue Doppler (S') in the apical 4-chamber TTE view and midesophageal 4-chamber TEE view (AP4C, ME4C). They then examined (1) the same measurements in alternative TEE views with proposed better ultrasound angulation; and (2) speckle tracking-based endpoints (TAPSE by speckle tracking, strain, and strain rate). Data were available in 24 of 25 patients. Conventional TAPSE by M-mode and velocity by tissue Doppler (TDI) were underestimated in the ME4C compared with the AP4C reference (mean ± standard deviation: TAPSE: 13.1 ± 3.8 mm v 17.3 ± 4.0 mm; S': 6.7 ± 2.1 cm/s v 9.1 ± 2.2 cm/s; both p < 0.001). Neither a modified deep transgastric view (TAPSE 14.5 ± 4.7 mm, p = 0.017; S' 6.8 ± 1.8 cm/s, p < 0.001) nor a transgastric right ventricular inflow view (TAPSE 12.3 ± 4.0 mm, p = 0.001; S' 6.0 ± 1.3 cm/s, p < 0.001) was similar to the AP4C. Speckle tracking TAPSE was unbiased but with high variability (mean bias = -0.3 mm, 95% limits of agreement = -9.1 to 8.4); strain and strain rate were higher in TEE than for TTE (-17.7 ± 3.6 v -12.6 ± 2.1, p < 0.001; -1.0 ± 0.2/s v -0.7 ± 0.1/s, p < 0.001).

CONCLUSIONS

Right ventricular displacement, velocity, and myocardial deformation measured by TEE versus TTE are different. Neither alternative transesophageal echocardiography views nor speckle tracking-based deformation is promising; TAPSE by speckle tracking is unbiased but imprecise.

Patients with left ventricle assist devices presenting for thoracic surgery and lung resection: tips, tricks and evidence

PURPOSE OF REVIEW

Over a thousand left ventricular-assist device (LVAD) implants were performed for heart failure destination therapy in 2017. With increasing survival, we are seeing increasing numbers of patients present for noncardiac surgery, including resections for cancer. This article will review the relevant literature and guidelines for patients with LVADs undergoing thoracic surgery, including lung resection.

RECENT FINDINGS

The International Society for Heart and Lung Transplant Mechanically Assisted Circulatory Support Registry has received data on more than 16 000 patients with LVADs. Four-year survival is more than 60% for centrifugal devices. There are increasing case reports, summaries and recommendations for patients with LVADs undergoing noncardiac surgery. However, data on thoracic surgery is restricted to case reports.

SUMMARY

Successful thoracic surgery requires understanding of the LVAD physiology. Modern devices are preload dependent and afterload sensitive. The effects of one-lung ventilation, including hypoxia and hypercapnia, may increase pulmonary vascular resistance and impair the right ventricle. Successful surgery necessitates a multidisciplinary approach, including thorough preoperative assessment; optimization and planning of intraoperative management strategies; and approaches to anticoagulation, right ventricular failure and LVAD flow optimization. This article discusses recent evidence on these topics.

Anesthetic management of a patient with a continuous-flow left ventricular assist device for video-assisted thoracoscopic surgery: a case report

Background

As patients with left ventricular assist device (LVAD) have long expected survival, the incidence of noncardiac surgery in this patient population is increasing. Here, we present the anesthetic management of a patient with a continuous-flow LVAD who underwent video-assisted thoracic surgery (VATS).

Case presentation

A 37-year-old man with LVAD was scheduled to undergo VATS because of repeated spontaneous pneumothorax. Generally, patients with these devices have marginal right heart function; therefore, it is important to avoid factors that worsen pulmonary vascular resistance (PVR). However, VATS requires one-lung ventilation (OLV) and it tends to cause increase in PVR, leading to right heart failure.

In the present case, when the patient was set in a lateral decubitus position and progressive hypoxia was observed during OLV, transesophageal echocardiography demonstrated a dilated right ventricle and a temporally flattened interventricular septum, and the central venous pressure increased to approximately 20 mmHg. Because we anticipated deterioration of right heart function, dobutamine and milrinone were administered and/or respirator settings were changed to decrease PVR for maintaining LVAD performance. Finally, resection of a bulla was completed, and the patient was discharged in stable condition on postoperative day 37.

Conclusions

The anesthetic management of a patient with LVAD during VATS is challenging because the possible hemodynamic changes induced by hypoxia associated with OLV affect LVAD performance and right heart function. In our experience, VATS that requires OLV will be well tolerated in a patient with LVAD with preserved right heart function, and a multidisciplinary approach to maintain right heart function will be needed.