Lung injury following cardiopulmonary bypass: a clinical update

Effects of different doses of ulinastatin on organ protection of deep hypothermic circulatory arrest in rats

BACKGROUND

Deep hypothermic circulatory arrest (DHCA) can cause systemic inflammatory response (SIR) and ischemia-reperfusion (I/R) injury, potentially exacerbating organ failure. Ulinastatin (UTI) is a frequently employed anti-inflammatory medication in clinical practice, but different timing and dosage may influence its protective efficacy.

METHODS

24 rats were randomly divided into four groups. Three different doses of UTI (3/10/30 × 104 U/kg; low/medium/high dose) were administered in the DHCA rat model, with a control group that underwent DHCA without UTI administration. Inflammatory markers and routine clinical indicators of myocardial, hepatic, and renal tissue injury were evaluated. All rats underwent the standard DHCA procedure.

RESULTS

Interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α) and neutrophil elastase (ELA-2) levels in rats exposed to DHCA gradually increased after rewarming. Compared with the DHCA-only group, both the low dose of UTI (UTI-L) and the medium dose of UTI (UTI-M) significantly reduced IL-6 (p = 0.017, p = 0.022 ), TNF-α (p = 0.003, p < 0.001), ELA-2 levels ( p = 0.018, p = 0.001), and elevated IL-10 levels ( p < 0.001, p < 0.001) 4 h post-weaning from cardiopulmonary bypass (CPB). In addition, compared with the DHCA group, both the UTI-L and UTI-M group showed significantly lower levels of cardiac troponin I (p = 0.001, p = 0.001), creatine kinase muscle and brain isoenzyme (CK-MB) (p < 0.001, p < 0.001), creatinine (p < 0.001, p < 0.001), blood urea nitrogen (p = 0.002, p = 0.021), aspartate transaminase (p < 0.001, p < 0.001) and alanine aminotransferase (p < 0.001, p < 0.001) at the end of the experiment. The hematoxylin-eosin staining results of kidney and liver tissue damage were alleviated in the UTI-L and UTI-M groups. The high dose of UTI (UTI-H) group did not exhibit dose-dependent anti-inflammatory effects and was associated with aggravated injury to the heart, liver, and kidney.

CONCLUSION

This study demonstrated that the administration of low to medium doses of UTI during DHCA significantly attenuated the levels of IL-6, TNF-α, and ELA-2, elevated the level of the anti-inflammatory factor IL-10, and provided protective effects on myocardial, hepatic, and renal tissues.

Efficacy of sivelestat in alleviating postoperative pulmonary injury in patients with acute aortic dissection undergoing total arch replacement: a retrospective cohort study

OBJECTIVE

Sivelestat may reduce postoperative pulmonary injury after total arch replacement (TAR). This study aimed to evaluate whether the preoperative PaO2/FiO2 (P/F) ratio affects the efficacy of sivelestat in reducing postoperative pulmonary injury in patients with acute aortic dissection (AAD) who underwent TAR using deep hypothermic circulatory arrest (DHCA).

METHODS

Data of patients with AAD who underwent TAR using DHCA in a tertiary hospital between February 1, 2022, and December 30, 2022, were retrospectively reviewed. The patients were divided into the sivelestat and control groups. Three subgroup analyses were performed based on the postoperative P/F ratio. The primary clinical outcomes were assessed to determine the efficacy and safety of sivelestat in managing postoperative pulmonary dysfunction in patients undergoing cardiopulmonary bypass.

RESULTS

A total of 187 patients were included, with 95 in the sivelestat group and 92 in the control group. No significant differences were found in the clinical variables between the two groups (all P > 0.05), except for some improvements in the inflammatory biomarker levels (including white blood cell count, neutrophil count, and C-reactive protein). Subgroup analysis revealed that sivelestat treatment significantly increased the P/F ratio on the 4th day and 3rd day after TAR in patients with mild lung injury (P = 0.02) and moderate lung injury (P = 0.03), respectively. Additionally, sivelestat reduced the levels of several postoperative inflammatory biomarkers in both subgroups.

CONCLUSIONS

Among patients with AAD with mild or moderate preoperative lung injury, defined by a low P/F ratio, sivelestat significantly improved the postoperative P/F ratio and attenuated inflammatory responses after TAR. These findings suggest an important avenue for further research.

Successful Treatment of Unilateral Pulmonary Edema as Minimally Invasive Mitral Valve Surgery Complication-Case Presentation

Background/Objectives: In recent decades, the advantages of minimizing surgical trauma have led to the development of minimally invasive surgical procedures. While the benefits often outweigh the risks, several challenges are encountered that are not present in conventional surgical approaches. Unilateral pulmonary edema (UPE) after mitral interventions performed through a right-sided approach is a rare but potentially life-threatening event. Methods: We present the case of a 49-year-old patient who underwent endoscopic mitral valve repair. Immediately following ICU admission, the patient's oxygen saturation suddenly dropped, and serous discharge was exteriorized from the endotracheal tube, with a thoracic X-ray revealing right-sided unilateral pulmonary edema. Results: The therapeutical course was complex. The patient developed hemodynamic instability, leading to cardiac arrest, which required cardiopulmonary resuscitation and the initiation of peripheral veno-arterial extracorporeal membrane oxygenation (VA-ECMO). The endotracheal cannula was replaced with a right-sided double-lumen cannula, and the patient was placed on two ventilators operating independently. The patient was weaned off extracorporeal membrane oxygenation (ECMO) on the fifth day and extubated on the sixth postoperative day. Conclusions: We successfully treated this patient using ECMO and independent lung ventilation. Several cases have been described in the literature, but the pathogenesis and risk factors of UPE remain unclear. Management depends on the severity of UPE, but a deeper understanding of its underlying mechanisms could provide cardiac surgeons with enhanced strategies for preventing UPE and implementing timely interventions.

Postoperative mechanical ventilation after corrective Tetralogy of Fallot surgery in infants: Assessment of perioperative factors and radiographic severity scores

Early recovery from surgery for congenital heart disease (CHD) is becoming a trend. Tetralogy of Fallot/pulmonary stenosis (TOF/PS) is the most common cyanotic CHD with excellent long-term outcomes. We examined potential factors associated with early extubation in 249 patients who underwent TOF/PS complete repair in a tertiary pediatric medical center from January 2015 to December 2022. Patient demographics, preoperative characteristics, intraoperative variables, postoperative outcomes, surgical type, surgical duration, cardiopulmonary bypass (CPB) time, cross-clamp time, and blood product volumes were acquired from the electronic medical records. Valve sparing repair (VSR) tends to demonstrate earlier recovery profiles than transannular patch repair (TAP) irrelevant of the presence of monocusp valve (P< 0.0001) and the degree of right ventricular outflow pressure drop was significantly correlated with post-operative recovery profile (p=0.0204). Because of intracardiac shunts and PaO2/FiO2 ratios being poor indicators of lung injury, Brixia scores were also used. Our data suggested that Brixia score could be an excellent alternative to evaluate post-operative lung status.

Low Frequency Ventilation During Cardiopulmonary Bypass to Protect Postoperative Lung Function in Cardiac Valvular Surgery: The PROTECTION Phase II Randomized Trial

BACKGROUND

Cardiac surgery with cardiopulmonary bypass (CPB) triggers pulmonary injury. In this trial we assessed the feasibility, safety, and efficacy of low frequency ventilation (LFV) during CPB in patients undergoing valvular surgery.

METHODS AND RESULTS

Patients with severe mitral or aortic valve disease were randomized to either LFV or usual care. Primary outcomes included release of generic inflammatory and vascular biomarkers and the lung-specific biomarker sRAGE (soluble receptor for advance glycation end products) up to 24 hours postsurgery. Secondary outcomes included pulmonary function tests and 6-minute walking test up to 8 weeks postdischarge. Sixty-three patients were randomized (33 LFV versus 30 usual care). Mean age was 66.8 years and 30% were female. LFV was associated with changes of sRAGE (soluble receptor for advance glycation end products) levels (geometric mean ratio, 3.05; [95% CI, 1.13-8.24] 10 minutes post CPB, and 1.07 [95% CI, 0.64-1.79], 0.84 [95% CI, 0.55-1.27], 0.67 [95% CI, 0.42-1.07], and 0.62 [95% CI, 0.45-0.85] at 2, 6, 12, and 24 hours post CPB respectively). No changes were observed for any of the generic biomarkers. Respiratory index soon after surgery (mean difference, -0.61 [95% CI, -1.24 to 0.015] 10 minutes post end of CPB), forced expiratory volume after 1 second/forced vital capacity ratio (0.050 [95% CI, 0.007-0.093] at 6 to 8 weeks pos-surgery), Forced vital capacity alone (95% CI, -0.191 L [-0.394 to 0.012]) and 6-minute walking test score at discharge (63.2 m [95% CI, 12.9-113.6]) were better preserved in the LFV group. No other differences were noted.

CONCLUSIONS

The use of LFV during CPB in patients undergoing valvular surgery was feasible and safe and was associated with changes in sRAGE levels along with better preserved lung function and walking performance. These observations warrant further investigation in larger future studies.

REGISTRATION

URL: https://www.isrctn.com; Unique Identifier: ISRCTN75795633.

Veno-venous extracorporeal membrane oxygenation for perioperative management of infective endocarditis after COVID-19 with acute respiratory distress syndrome: a case report

BACKGROUND

Infective endocarditis (IE) is a rare cardiovascular complication in patients with coronavirus disease 2019 (COVID-19). IE after COVID-19 can also be complicated by acute respiratory distress syndrome (ARDS); however, the guidelines for the treatment of such cases are not clear. Here, we report a case of perioperative management of post-COVID-19 IE with ARDS using veno-venous extracorporeal membrane oxygenation (V-V ECMO).

CASE PRESENTATION

The patient was a 40-year-old woman who was admitted on day 18 of COVID-19 onset and was administered oxygen therapy, remdesivir, and dexamethasone. The patient's condition improved; however, on day 24 of hospitalization, the patient developed hypoxemia and was admitted to the intensive care unit (ICU) due to respiratory failure. Blood culture revealed Corynebacterium striatum, and transesophageal echocardiography revealed vegetation on the aortic and mitral valves. Valve destruction was mild, and the cause of respiratory failure was thought to be ARDS. Despite continued antimicrobial therapy, ARDS did not improve the patient's condition, and valve destruction progressed; therefore, surgical treatment was scheduled on day 13 of ICU admission. After preoperative consultation with the team, a decision was made to initiate V-V ECMO after the patient was weaned from CPB, with concerns about further worsening of her respiratory status after surgery. The patient returned to the ICU with transition to V-V ECMO, and her circulation remained stable. The patient was weaned off V-V ECMO on postoperative day 33 and discharged from the ICU on postoperative day 47.

CONCLUSIONS

ARDS may occur in patients with IE after COVID-19. Owing to concerns about further exacerbation of pulmonary damage, the timing of surgery should be comprehensively considered. Preoperatively, clinicians should discuss perioperative ECMO introduction and configuration.

Severe Mitral Valve Regurgitation in Infective Endocarditis: A Case Report

We present a case report of a patient with infective endocarditis. He came to the emergency room with respiratory failure due to severe pneumonia and pulmonary edema. On 2D transesophageal echocardiography, vegetations were seen in both mitral and aortic valves, with mitral valve perforation and severe regurgitation. His clinical presentation and severity of the disease made him suitable for urgent valve repair. He was submitted to mitral valvuloplasty with closure of the valve perforation and insertion of a bioprosthetic aortic valve. Despite significant clinical improvement, a post-surgical complication was noted with new-onset lung injury after cardiopulmonary bypass. This is an interesting case of a patient with suspected retrograde valve involvement, affecting the aortic valve, the mitral-aortic intervalvular fibrosa, and the mitral valve, ending with mitral valve abscess with leaflet perforation and valvular regurgitation.

Con: Mechanical Ventilation During Cardiopulmonary Bypass

The ventilatory strategy to adopt during cardiopulmonary bypass is still being debated. The rationale for using continuous positive airway pressure or mechanical ventilation would be to counteract alveolar collapse and improve ischemia phenomena and passive alveolar diffusion of oxygen. Although there are several studies supporting the hypothesis of a positive effect on oxygenation and systemic inflammatory response, the real clinical impact of ventilation during cardiopulmonary bypass is controversial. Furthermore, the biases present in the literature make the studies' results nonunique in their interpretation.

Modified aortic root anastomosis and the frozen elephant trunk technique using an integrated tetra-furcate graft to repair type A aortic dissection

BACKGROUND

Surgery is the preferred treatment for acute Stanford type A aortic dissection (STAAD); however, due to the complexity of the procedure, cardiac ischaemia and cardiopulmonary bypass (CPB) time are longer than general heart surgery, leading to complications. In this present study, we used an integrated tetra-furcate graft for both modified aortic root and distal arch anastomoses (frozen elephant trunk technique, [FET]), and investigated postoperative outcomes associated with this technique in patients with STAAD.

METHODS

We included a total of 140 patients who underwent total arch replacement and FET between January 2019 and June 2022 in the present study, 41 patients who underwent the modified technique, and 99 who underwent the graft eversion technique. We subsequently analyzed the perioperative outcomes to compare the differences between the two techniques.

RESULTS

There were no statistically significant differences between the two groups in regards to the preoperative characteristics; however, the intraoperative CPB, cardiac ischaemia, and operation times of the modified technique group were significantly shorter than those of the eversion technique group (P = 0.02, P = 0.01, and P = 0.04, respectively), as were postoperative hypoxaemia, intensive care unit (ICU) stay, and ventilation times (P = 0.04, P = 0.03, and P = 0.04, respectively). Additionally, the degree of postoperative bilirubin elevation was milder in the modified technique group (P = 0.002 for direct bilirubin and P = 0.01 for indirect bilirubin).

CONCLUSIONS

The modified anastomosis technique can significantly shorten CPB, cardiac ischemia, and operation times, and reduce the intraoperative FFP transfusion and postoperative hypoxemia times. This modified technique, therefore, is worth utilizing for patients with STAAD.

Risk Factors and Short-Term Outcomes of Postoperative Pulmonary Complications in Elderly Patients After Cardiopulmonary Bypass

Objective

The risk factors of postoperative pulmonary complications (PPCs) have been extensively investigated in non-cardiac surgery and non-elderly adult patients undergoing cardiac surgery. However, data on elderly patients after cardiopulmonary bypass (CPB) is limited. This study aimed to evaluate the risk factors and short-term outcomes for PPCs in elderly patients undergoing CPB procedures.

Patients and Methods

Data from 660 patients who underwent CPB over a six-year period at a tertiary care hospital were collected. The primary outcome encompassed the incidence of PPCs, including re-intubation, postoperative mechanical ventilation exceeding 48 hours, pulmonary infection, pleural effusion requiring thoracic drainage, and acute respiratory distress syndrome. Missing data were managed using multiple imputation. Univariate analysis and the multiple logistic regression method were utilized to ascertain independent risk factors for PPCs.

Results

Among the 660 patients, PPCs were observed in 375 individuals (56.82%). Multiple logistic regression identified serum albumin levels <40 g/L, type of surgery, CPB duration >150 minutes, blood transfusion, and intra-aortic balloon pump use before extubation as independent risk factors for PPCs. Patients experiencing PPCs had prolonged mechanical ventilation, extended hospitalization and ICU stays, elevated postoperative mortality, and higher tracheotomy rates compared to those without PPCs.

Conclusion

Elderly patients following CPB displayed a substantially high incidence of PPCs, significantly impacting their prognosis. Additionally, this study identified five prominent risk factors associated with PPCs in this population. These findings enable clinicians to better recognize patients who may benefit from perioperative prevention strategies based on these risk factors.