ICU Care Before and After Lung Transplantation

Perioperative fluid balance and early acute kidney injury after lung transplantation

BACKGROUND

Postoperative acute kidney injury (AKI) after lung transplantation (LTx) is an important factor affecting the short-term outcomes. The focus item of transplantation centers is how to improve the incidence of AKI through optimal management during the perioperative period.

OBJECTIVE

The purpose of the study is to investigate the influence of perioperative volume in the development of early AKI following LTx.

METHOD

The study involved patients who had undergone LTx between October 2018 to December 2021 at China-Japan Friendship Hospital in Beijing. The patients were monitored for AKI occurring within 72 hours after LTx, as well as the renal outcomes within 30 days. The perioperative volumes were compared and analyzed to determine the impact on various clinical outcomes.

RESULTS

248 patients were enrolled in the study ultimately, with almost half of them (49.6 %) experiencing AKI. 48.8 % of AKI patients received continuous renal replacement therapy (CRRT), with 57.7 % recovered by the end of the 30-day follow-up period. A J-shaped relationship was demonstrated between perioperative volume and AKI incidence. Moreover, maintaining a positive fluid balance would increase the 30-day mortality and lead to poor renal outcomes.

CONCLUSION

Perioperative volume is an independent risk factor of early AKI after LTx. Positive fluid balance increases the risk of AKI, 30-day mortality, and adverse renal prognosis. The LTx recipients may benefit from a relatively restrict fluid strategy during and after the lung transplantation.

A two-circuit strategy for intraoperative extracorporeal support during single lung transplantation in a patient bridged with venovenous extracorporeal membrane oxygenation

Venovenous extracorporeal membrane oxygenation is increasingly used as a bridging strategy in decompensating patients awaiting lung transplantation. Various approaches for continuing support intraoperatively have been previously described. A two-circuit strategy that uses the in situ venovenous extracorporeal membrane oxygenation circuit supplemented with peripheral cardiopulmonary bypass allows for diversion of native cardiac output away from the transplanted lung as well as seamless continuation of venovenous extracorporeal membrane oxygenation postoperatively.

Impact of delayed veno-venous extracorporeal membrane oxygenation weaning on postoperative rehabilitation of lung transplantation: a single-center comparative study

Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is a reliable and effective extracorporeal life support during lung transplantation (LTx). However, the clinical benefit of delayed VV-ECMO weaning remains unclear. The current study aims to investigate whether delayed weaning of VV-ECMO is more beneficial to the rehabilitation for lung transplant patients. Patients who underwent LTx with VV-ECMO between January 2017 and January 2019 were included. Enrollment of patients was suitable for weaning off ECMO immediately after surgery. Randomization was performed in the operating room. Postoperative outcomes were compared between the two groups. Besides, univariate and multivariable logistic regressions were performed to estimate risk of postoperative complications. Compared to VV-ECMO weaning immediately after LTx, delayed weaning was associated with shorter hospital length of stay (days, 31 vs. 46; P < 0.05), lower incidence of noninvasive ventilation (4.3% vs. 24.4%; P < 0.05), primary graft dysfunction (PGD) (6.4% vs. 29.3%; P < 0.05), atrial fibrillation (AF) (4.3% vs. 22%, P < 0.05), and respiratory failure (4.3% vs. 19.5%; P < 0.05). Multivariable logistic regressions revealed that VV-ECMO weaning after LTx was independently correlated with increased risk of developing PGD [odds ratio (OR), 5.97, 95% CI 1.16-30.74], AF (OR, 6.87, 95% CI 1.66-28.47) and respiratory failure (OR, 6.02, 95% CI 1.12-32.49) by comparison of delayed VV-ECMO weaning. Patients with delayed VV-ECMO weaning are associated with lower complications and short hospital length of stay, while it relates to longer mechanical ventilation. These findings suggest that delayed VV-ECMO after LTx can facilitate rehabilitation.

Effects of intraoperative fluid therapy on intensive care process, morbidity, and mortality after lung transplantation

Background

This study aims to evaluate the effect of intraoperative fluid therapy on intensive care process and first 90-day morbidity and mortality in patients undergoing lung transplantation.

Methods

Between March 2013 and December 2020, a total of 77 patients (64 males, 13 females; mean age: 47.6±13.0 years; range, 19 to 67 years) who underwent lung transplantation were retrospectively analyzed. The patients were divided into two groups according to the amount of fluid given intraoperatively: Group 1 (<15 mL/kg^-1/h^-1) and Group 2 (>15 mL/kg^-1/h^-1). Demographic, clinical, intra- and postoperative data of the patients were recorded.

Results

Less than 15 mL/kg-1/h-1 f luid w as a dministered t o 75.3% (n=58) of the patients (Group 1) and 24.7% (n=19) were administered more than 15 mL/kg-1/h-1 (Group 2). In t erms of native disease, the rate of diagnosis of chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis was higher in Group 1, and the rate of other diagnoses was higher in Group 2 (p<0.01). The ratio of women in Group 2 was higher (p<0.05), while the body mass index values were significantly lower in this group (p<0.01). The erythrocyte, fresh frozen plasma, platelet, crystalloid and total fluid given in Group 2 were significantly higher (p<0.001). Inotropic/vasopressor agent use rates and extracorporeal membrane oxygenation requirement were significantly higher in Group 2 (p<0.01). Primary graft dysfunction, gastrointestinal complications, and mortality rates were also significantly higher in Group 2 (p<0.05).

Conclusion

The increased intraoperative fluid volume in lung transplantation is associated with primary graft dysfunction, gastrointestinal complications, and mortality rates.

Roles of electrical impedance tomography in lung transplantation

Lung transplantation is the preferred treatment method for patients with end-stage pulmonary disease. However, several factors hinder the progress of lung transplantation, including donor shortages, candidate selection, and various postoperative complications. Electrical impedance tomography (EIT) is a functional imaging tool that can be used to evaluate pulmonary ventilation and perfusion at the bedside. Among patients after lung transplantation, monitoring the graft’s pulmonary function is one of the most concerning issues. The feasible application of EIT in lung transplantation has been reported over the past few years, and this technique has gained increasing interest from multidisciplinary researchers. Nevertheless, physicians still lack knowledge concerning the potential applications of EIT in lung transplantation. We present an updated review of EIT in lung transplantation donors and recipients over the past few years, and discuss the potential use of ventilation- and perfusion-monitoring-based EIT in lung transplantation.

Critical Care of the Lung Transplant Patient

Lung transplantation is a therapeutic option for end-stage lung disease that improves survival and quality of life. Prelung transplant admission to the intensive care unit (ICU) for bridge to transplant with mechanical ventilation and extracorporeal membrane oxygenation (ECMO) is common. Primary graft dysfunction is an important immediate complication of lung transplantation with short- and long-term morbidity and mortality. Later transplant-related causes of respiratory failure necessitating ICU admission include acute cellular rejection, atypical infections, and chronic lung allograft dysfunction. Lung transplantation for COVID-19-related ARDS is increasingly common..

Critical Care Management Following Lung Transplantation

Postoperative critical care management for lung transplant recipients in the intensive care unit (ICU) has expanded in recent years due to its complexity and impact on clinical outcomes. The practical aspects of post-transplant critical care management, especially regarding ventilation and hemodynamic management during the early postoperative period in the ICU, are discussed in this brief review. Monitoring in the ICU provides information on the patient’s clinical status, diagnostic assessment of complications, and future management plans since lung transplantation involves unique pathophysiological conditions and risk factors for complications. After lung transplantation, the grafts should be appropriately ventilated with lung protective strategies to prevent ventilator-induced lung injury, as well as to promote graft function and maintain adequate gas exchange. Hypotension and varying degrees of pulmonary edema are common in the immediate postoperative lung transplantation setting. Ventricular dysfunction in lung transplant recipients should also be considered. Therefore, adequate volume and hemodynamic management with vasoactive agents based on their physiological effects and patient response are critical in the early postoperative lung transplantation period. Integrated management provided by a professional multidisciplinary team is essential for the critical care management of lung transplant recipients in the ICU.

Screening gene signatures for clinical response subtypes of lung transplantation

Lung is the most important organ in the human respiratory system, whose normal functions are quite essential for human beings. Under certain pathological conditions, the normal lung functions could no longer be maintained in patients, and lung transplantation is generally applied to ease patients' breathing and prolong their lives. However, several risk factors exist during and after lung transplantation, including bleeding, infection, and transplant rejections. In particular, transplant rejections are difficult to predict or prevent, leading to the most dangerous complications and severe status in patients undergoing lung transplantation. Given that most common monitoring and validation methods for lung transplantation rejections may take quite a long time and have low reproducibility, new technologies and methods are required to improve the efficacy and accuracy of rejection monitoring after lung transplantation. Recently, one previous study set up the gene expression profiles of patients who underwent lung transplantation. However, it did not provide a tool to predict lung transplantation responses. Here, a further deep investigation was conducted on such profiling data. A computational framework, incorporating several machine learning algorithms, such as feature selection methods and classification algorithms, was built to establish an effective prediction model distinguishing patient into different clinical subgroups, corresponding to different rejection responses after lung transplantation. Furthermore, the framework also screened essential genes with functional enrichments and create quantitative rules for the distinction of patients with different rejection responses to lung transplantation. The outcome of this contribution could provide guidelines for clinical treatment of each rejection subtype and contribute to the revealing of complicated rejection mechanisms of lung transplantation.

Ethics in extracorporeal life support: a narrative review

During 50 years of extracorporeal life support (ECLS), this highly invasive technology has left a considerable imprint on modern medicine, and it still confronts researchers, clinicians and policymakers with multifarious ethical challenges. After half a century of academic discussion about the ethics of ECLS, it seems appropriate to review the state of the argument and the trends in it. Through a comprehensive literature search on PubMed, we identified three ethical discourses: (1) trials and evidence accompanying the use of ECLS, (2) ECLS allocation, decision-making and limiting care, and (3) death on ECLS and ECLS in organ donation. All included articles were carefully reviewed, arguments extracted and grouped into the three discourses. This article provides a narrative synthesis of these arguments, evaluates the opportunities for mediation and substantiates the necessity of a shared decision-making approach at the limits of medical care.

A novel highly bio-available itraconazole formulation (SUBA®-Itraconazole) for anti-fungal prophylaxis in lung transplant recipients

BACKGROUND

Antifungal prophylaxis remains a mainstay of lung transplantation, given invasive fungal infection is a common and serious complication after lung transplantation. Choice of systemic agent to prevent invasive fungal infection varies between centers and funding of agents remains challenging. Our center has recently changed from posaconazole to a highly bioavailable formulation of itraconazole (SUBA®-itraconazole) at substantially reduced cost, but safety and toxicity require further assessment. A retrospective study of lung transplant patients receiving systemic antifungal prophylaxis from December 2016 through December 2019 following change from posaconazole to itraconazole as standard practice. 150 patients with lung transplants were managed in this time period, with 88 (59%) receiving at least 1 mold-active triazole during the study period. 48 (58%) of these patients received SUBA®-itraconazole; 68 (82%) received posaconazole and 10 (12%) received voriconazole. The average cost per patient during the study period was significantly lower on SUBA®-itraconazole (mean $1548/patient/6 month course) than posaconazole (mean $16 921.35/patient/6 month course). Target trough concentrations for prophylaxis of itraconazole > 0.5 mg/L and posaconazole > 0.7 mg/L were achieved on empiric dosing in 49% and 68% respectively. Overall trough itraconazole (0.50 vs 1.12 mg/L, P < .001) and posaconazole (1.37 vs 2.10 mg/L P < .001) concentrations were significantly lower in patients with cystic fibrosis. Calcineurin inhibitor dose changes on introduction or cessation were similar for SUBA®-itraconazole and posaconazole. Breakthrough invasive fungal infection and toxicity were rare. SUBA®-itraconazole is well-tolerated, associated with rare breakthrough invasive fungal infection, and lower cost. Prospective studies following general introduction are required to determine long-term safety, tolerability, and efficacy.

Invasive Fungal Infection After Lung Transplantation: Epidemiology in the Setting of Antifungal Prophylaxis

BACKGROUND

Lung transplant recipients commonly develop invasive fungal infections (IFIs), but the most effective strategies to prevent IFIs following lung transplantation are not known.

METHODS

We prospectively collected clinical data on all patients who underwent lung transplantation at a tertiary care academic hospital from January 2007-October 2014. Standard antifungal prophylaxis consisted of aerosolized amphotericin B lipid complex during the transplant hospitalization. For the first 180 days after transplant, we analyzed prevalence rates and timing of IFIs, risk factors for IFIs, and data from IFIs that broke through prophylaxis.

RESULTS

In total, 156 of 815 lung transplant recipients developed IFIs (prevalence rate, 19.1 IFIs per 100 surgeries, 95% confidence interval [CI] 16.4-21.8%). The prevalence rate of invasive candidiasis (IC) was 11.4% (95% CI 9.2-13.6%), and the rate of non-Candida IFIs was 8.8% (95% CI 6.9-10.8%). First episodes of IC occurred a median of 31 days (interquartile range [IQR] 16-56 days) after transplant, while non-Candida IFIs occurred later, at a median of 86 days (IQR 40-121 days) after transplant. Of 169 IFI episodes, 121 (72%) occurred in the absence of recent antifungal prophylaxis; however, IC and non-Candida breakthrough IFIs were observed, most often representing failures of micafungin (n = 16) and aerosolized amphotericin B (n = 24) prophylaxis, respectively.

CONCLUSIONS

Lung transplant recipients at our hospital had high rates of IFIs, despite receiving prophylaxis with aerosolized amphotericin B lipid complex during the transplant hospitalization. These data suggest benefit in providing systemic antifungal prophylaxis targeting Candida for up to 90 days after transplant and extending mold-active prophylaxis for up to 180 days after surgery.

Postoperative Management of Hyperinflated Native Lung in Single-Lung Transplant Recipients with Chronic Obstructive Pulmonary Disease: A Review Article

End-stage chronic obstructive pulmonary disease (COPD) is the most common indication for single- or double-lung transplantation. Acute native lung hyperinflation (ANLH) is a unique postoperative complication of single-lung transplantation for COPD patients, with incidence varying in the medical literature from 15 to 30%. The diagnosis is made radiographically by contralateral mediastinal shift and ipsilateral diaphragmatic flattening. ANLH can deteriorate into hemodynamic instability, and respiratory impairment can result from compression of the allograft, which can precipitate atelectasis, hypoxemia, and hypercapnia, necessitating specific ventilatory intervention or volume reduction surgery. Currently, there is consensus for a therapeutic role of noninvasive positive pressure ventilation (NIPPV) in acute respiratory failure after lung transplantation as a well-tolerated measure to avoid re-intubation. This manuscript presents a concise review on the diagnosis and treatment of ANLH following unilateral lung transplant, along with a management algorithm created by the authors.

Predictors of long intensive care need after lung transplantation

BACKGROUND

While expected need for intensive care after lung transplantation (LTx) does not normally affect organ allocation, it would be useful to estimate whether intensive care capacity is limited. The aim of this study was to assess factors available before LTx to identify predictors of prolonged intensive care unit (ICU) length of stay (LOS) after LTx.

METHODS

All bilateral LTx recipients excluding re-transplantation and multi-organ transplantation at Oslo University Hospital from 2000 to 2013 were included (n = 277). Predictive factors for ICU LOS were identified using pre- and perioperative variables.

RESULTS

Univariate analyses showed that recipients with pulmonary arterial hypertension, young age, female gender, low body height, low pretransplant actual total lung capacity (aTLC), and recipients who received an oversized donor lung were at risk for long ICU LOS. Patients with emphysema had lower risk of long ICU LOS. In multivariate analyses, a lower aTLC (p < .001) and a higher mean pulmonary artery pressure (mPAP) (p = .004) predicted prolonged ICU LOS.

CONCLUSIONS

We found that small recipient lung volume and high mPAP were predictors for prolonged ICU LOS. Our observations may be useful in planning use of resources in LTx, particularly in times of limited intensive care resources.

Improved survival after lung transplantation for adults requiring preoperative invasive mechanical ventilation: A national cohort study

OBJECTIVE

Early survival after lung transplantation has improved in the last decade. Mechanically ventilated recipients are known to be at greater risk for early post-transplant mortality. We hypothesized that post-transplant survival in mechanically ventilated recipients has improved over time.

METHODS

Using a national registry, we compared hazard of death at 30 days, 4 and 14 months, 3 and 5 years, and overall for adults on mechanical ventilation who underwent lung or heart-lung transplantation from May 4, 2011, to April 4, 2018 (modern group) with those undergoing transplantation from May 4, 2005, to May 3, 2011 (early group). We quantified the impact of mechanical ventilation on survival using population-attributable fractions. We also compared mechanically ventilated recipients with nonmechanically ventilated recipients.

RESULTS

Mechanically ventilated recipients from the modern group had lower hazard of death than recipients in the early group at all time-points, lowest at 30-days post-transplant (hazard ratio, 0.04; 95% confidence interval, 0.02-0.08). In the modern period, mechanically ventilated recipients had greater hazard of death than nonmechanically ventilated recipients at 30 days' post-transplant (9.53; 4.57-19.86). For mechanically ventilated recipients, the population attributable fraction was lower in the modern group compared to the earlier group (0.6% vs 5.7%).

CONCLUSIONS

While mechanically ventilated recipients remain at high risk, survival in this patient population has improved over time. This may reflect improvements in perioperative recipient management.

Postoperative management of lung transplant recipients

Despite advances in surgical technique, lung transplantation is associated with worse survival when compared with other solid organ transplantations. Graft dysfunction and infection are the leading causes of mortality in the first 30 days following transplantation. Primary graft dysfunction (PGD) is a form of reperfusion injury that occurs early after transplantation. Management of PGD is mainly supportive with use of lung protective ventilation. Inhaled nitric oxide (iNO) and extracorporeal membrane oxygenation may be used in severe cases. Bacterial pneumonias are the most common infectious complication in the immediate post transplant period, but invasive fungal infections may also occur. Other potential complications in the postoperative period include atrial arrhythmias and neurologic complications such as stroke. There is a lack of multicenter, randomized trials to guide ventilation strategies, infection prophylaxis, and treatment of atrial arrhythmias, therefore prevention and management of post-transplant complications vary by transplant center.

Perioperative Management of the Lung Graft Following Lung Transplantation

Perioperative management of patients undergoing lung transplantation is one of the most complex in cardiothoracic surgery. Certain perioperative interventions, such as mechanical ventilation, fluid management and blood transfusions, use of extracorporeal mechanical support, and pain management, may have significant impact on the lung graft function and clinical outcome. This article provides a review of perioperative interventions that have been shown to impact the perioperative course after lung transplantation.

Extracorporeal Life Support as a Bridge to Lung Transplantation in Patients With Acute Respiratory Failure

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is being used more often as a bridge to transplantation (BTT) in patients with acutely decompensated end-stage lung disease in Korea. ECMO as a BTT may be the only rescue strategy for severe acute respiratory failure, but many centers still consider it to be a relative contraindication to lung transplantation because of its poor outcome. Because there are not enough lung donors, it is important to determine their optimal use. We reviewed and analyzed our experiences with the use of ECMO as a BTT in patients with acute respiratory failure.

METHODS

This was a retrospective analysis of all patients with acutely decompensated end-stage lung disease treated with ECMO as a bridge to lung transplantation between March 2012 and February 2016.

RESULTS

Of the 194 patients who underwent respiratory ECMO over a 4-year period, a BTT strategy was used for 19 patients (median age, 58 years) on our institution's lung transplantation waiting list (15 veno-venous, 3 veno-veno-arterial, 1 veno-arterial). Fourteen patients (73.7%) were successfully bridged to transplantation; however, 3 died while on the waiting list and 2 returned to their baseline functions without transplantation. The overall in-hospital survival rate was 57.9% (11 of 19), including the 9 (64.3%) patients who underwent transplantation.

CONCLUSIONS

Our findings support the view that well-selected candidates with acutely decompensated end-stage lung disease may be safely bridged until a suitable donor is identified. ECMO is not able to reverse the course of patients; however, it could be a life-saving option for patients with acute respiratory failure requiring lung transplantation.

Recent advances in extracorporeal life support as a bridge to lung transplantation

INTRODUCTION

Invasive mechanical respiratory support in candidate bridging to transplant (BTT) has become common practice in recent years. This usually consists of mechanical ventilation, extracorporeal life support (ECLS) or a combination of both techniques. Areas covered: This review covers epidemiology, technical considerations, indications and outcome of ELCS as BTT. Published literature was identified by searching the MEDLINE bibliographic database (1946-present) and appropriate papers were reviewed. In a retrospective analysis of the period 2010-2016 (n = 92 cases of ECLS bridging, 62% ECLS only) at our institution, bridging success was 73%, with 1-year survival among patients surviving to transplant 78%, surpassing our previously published results between 2005-2009 (bridging success 58%, 1-year survival 58%, p = 0.002 and p = 0.02, respectively). Expert commentary: While ECLS success has influenced lung transplant selection criteria, bridging remains technically and ethically challenging. Candidate selection and organ allocation are crucial to achieving acceptable results.

Care of the Postoperative Pulmonary Resection Patient

Patients undergoing pulmonary resection all exhibit, to some degree, a level of pulmonary dysfunction. This is due to the physiologic stress of the procedure performed, the patient’s comorbidities, and preexisting cardiopulmonary reserve. Although prognostic factors for intensive care requirement exist, to date, there is no consensus for postoperative admission. Institutional practices vary across the country, with patients often admitted to intensive care for surveillance. Guidelines published from the American Thoracic Society in 1999 emphasize that admission to the ICU be reserved for those patients requiring care and monitoring for severe physiologic instability. Admissions following pulmonary resection are typically due to respiratory complications and are an independent predictor of mortality. The following chapter will review the indications for admission to the ICU and common issues encountered following pulmonary resection and conclude with a discussion of the management of patients undergoing pulmonary transplantation.

Sequential use of extracorporeal devices to avoid mechanical ventilation in a patient with complicated pulmonary fibrosis

Extracorporeal lung assist devices are widely used these days for a growing number of indications. We report the case of a patient managed with three different flow-range devices sequentially, enabling us to avoid mechanical ventilation. Handling and ethics of this approach are discussed.