The multifactorial dynamic perfusion index: A predictive tool of cardiac surgery associated acute kidney injury

INTRODUCTION

cardiac surgery associated acute kidney injury (CSA-AKI) has a number of preoperative and intraoperative risk factors. Cardiopulmonary bypass (CPB) factors have not yet been elucidated in a single multivariate model. The aim of this study is to develop a dynamic predictive model for CSA-AKI.

METHODS

retrospective study on 910 consecutive adult cardiac surgery patients. Baseline data were used to settle a preoperative CSA-AKI risk model (static risk model, SRM); CPB related data were assessed for association with CSA-AKI. CPB duration, nadir oxygen delivery, time of exposure to a low oxygen delivery, nadir mean arterial pressure, peak lactates and red blood cell transfusion were included in a multivariate dynamic perfusion risk (DPR). SRM and DPR were merged into a final logistic regression model (multifactorial dynamic perfusion index, MDPI). The three risk models were assessed for discrimination and calibration.

RESULTS

the SRM model had an AUC of 0.696 (95% CI 0.663-0.727), the DPR model of 0.723 (95% CI 0.691-0.753), and the MDPI model an AUC of 0.769 (95% CI 0.739-0.798). The difference in AUC between SRM and DPR was not significant (p = 0.495) whereas the AUC of MDPI was significantly larger than that of SRM (p = 0.004) and DPR (p = 0.015).

CONCLUSIONS

inclusion of dynamic indices of the quality of CPB improves the discrimination and calibration of the preoperative risk scores. The MDPI has better predictive ability than the existing static risk models and is a promising tool to integrate different factors into an advanced concept of goal-directed perfusion.

Dexmedetomidine Pretreatment Confers Myocardial Protection and Reduces Mechanical Ventilation Duration for Patients Undergoing Cardiac Valve Replacement under Cardiopulmonary Bypass

PURPOSE

The study aims to assess the effects of dexmedetomidine (Dex) pretreatment on patients during cardiac valve replacement under cardiopulmonary bypass.

METHODS

For patients in the Dex group (n = 52), 0.5 μg/kg Dex was given before anesthesia induction, followed by 0.5 μg/kg/h pumping injection before aortic occlusion. For patients in the control group (n = 52), 0.125 ml/kg normal saline was given instead of Dex.

RESULTS

The patients in the Dex group had longer time to first dose of rescue propofol than the control group (P = 0.003). The Dex group required less total dosage of propofol than the control group (P = 0.0001). The levels of cardiac troponin I (cTnI), creatine kinase isoenzyme MB (CK-MB), malondialdehyde (MDA), and tumor necrosis factor-α (TNF-α) were lower in the Dex group than the control group at T4, 8 h after the operation (T5), and 24 h after the operation (T6) (P <0.01). The Dex group required less time for mechanical ventilation than the control group (P = 0.003).

CONCLUSION

The study suggests that 0.50 µg/kg Dex pretreatment could reduce propofol use and the duration of mechanical ventilation, and confer myocardial protection without increased adverse events during cardiac valve replacement.

Removal of stuck tunnelled dialysis line requiring cardiopulmonary bypass and venous repair

Tunnelled central venous dialysis catheters can usually be removed easily. However, their removal can become rarely complicated requiring more invasive techniques. We report a case in which cardiopulmonary bypass and repair of great veins was required for safe removal. A 38-year-old female with end-stage renal failure and a 3-year-old Hickman line inserted into her right internal jugular vein was referred to our cardiac surgical unit following failed attempts of line removal by local vascular surgical team using open vascular surgical techniques. As a result, an MDT decision was made that it was safer to proceed to a cardiothoracic surgical approach rather than other techniques. Investigations showed significant calcification surrounding the line which was adherent to the venous wall. Removal of the retained catheter required median sternotomy and the use of cardiopulmonary bypass as the great veins had to be opened to free the line and allow complete removal. The line was successfully removed with its encircling calcified sheath, and the veins were closed primarily without needing a patch repair. The integrity of the great veins was maintained to meet the on-going need this young patient has for central venous access. The patient made an uneventful recovery. When other measures fail, sternotomy and cardiopulmonary bypass provide a safe option for complete removal of stuck central venous catheters with low risk to the patient.

Discovery of plasma proteome markers associated with clinical outcome and immunological stress after cardiac surgery

Background

Molecular mechanisms underlying perioperative acute phase reactions in cardiac surgery are largely unknown. We aimed to characterise perioperative alterations of the acute phase plasma proteome in a cohort of adult patients undergoing on-pump cardiac surgery using high-throughput mass spectrometry and to identify candidate proteins potentially relevant to postoperative clinical outcome through a novel, multi-step approach.

Methods

This study is an analysis of the Bern Perioperative Biobank, a prospective cohort of adults who underwent cardiac surgery with the use of cardiopulmonary bypass (CPB) at Bern University Hospital between January and December 2019. Blood samples were taken before induction of anaesthesia and on postoperative day one. Proteomic analyses were performed by mass spectrometry. Through a multi-step, exploratory approach, hit-proteins were first identified according to their perioperative prevalence and dynamics. The set of hit-proteins were associated with predefined clinical outcome measures (all-cause one-year mortality, length of hospital stay, postoperative myocardial infarction and stroke until hospital discharge).

Results

192 patients [75.5% male, median age 67.0 (IQR 60.0-73.0)] undergoing cardiac surgery with the use of CPB were included in this analysis. In total, we identified and quantified 402 proteins across all samples, whereof 30/402 (7%) proteins were identified as hit-proteins. Three hit-proteins-LDHB, VCAM1 and IGFBP2-demonstrated the strongest associations with clinical outcomes. After adjustment both for age, sex, BMI and for multiple comparisons, the scaled preoperative levels of IGFBP2 were associated with 1-year all-cause mortality (OR 10.63; 95% CI: 2.93-64.00; p = 0.046). Additionally, scaled preoperative levels of LDHB (OR 5.58; 95% CI: 2.58-8.57; p = 0.009) and VCAM1 (OR 2.32; 95% CI: 0.88-3.77; p = 0.05) were found to be associated with length of hospital stay.

Conclusions

We identified a subset of promising candidate plasma proteins relevant to outcome after on-pump cardiac surgery. IGFBP2 showed a strong association with clinical outcome measures and a significant association of preoperative levels with 1-year all-cause mortality. Other proteins strongly associated with outcome were LDHB and VCAM1, reflecting the dynamics in the acute phase response, inflammation and myocardial injury. We recommend further investigation of these proteins as potential outcome markers after cardiac surgery.

Clinical Trial Registration

ClinicalTrials.gov; NCT04767685, data are available via ProteomeXchange with identifier PXD046496.

Creatinine Reduction Ratio Is a Prognostic Factor for Acute Kidney Injury following Cardiac Surgery with Cardiopulmonary Bypass: A Single-Center Retrospective Cohort Study

Acute kidney injury (AKI) after cardiac surgery is a common complication that can lead to death. We previously reported that the creatinine reduction ratio (CRR) serves as a useful prognostic factor for AKI. The primary objective of this study was to determine the predictors of AKI after surgery. The secondary objective was to determine the reliability of the CRR for short- and long-term outcomes. We retrospectively collected information about cardiac surgery patients who underwent cardiopulmonary bypass. Patients were divided into AKI and non-AKI groups based on the AKIN and RIFLE criteria. We analyzed the two groups regarding the preoperative patient data and operative information. The CRR was calculated as follows: (preoperative creatinine-postoperative creatinine)/preoperative creatinine. The prognostic factors of AKI-CS were surgery time, CPB time, aorta clamp time, platelet transfusion, and CRR < 20%. In the multivariate logistical analysis, CRR was an independent predictor of AKI (adjusted odds ratio: 0.90 [0.87-0.93], p < 0.001). However, there were no significant differences in CRR in terms of the rate of new onset chronic kidney disease (CKD). After cardiac surgery with cardiopulmonary bypass, CRR has good diagnostic power for predicting perioperative AKI. However, we cannot use it as a prognostic factor over a long-term period.

Comparison of six percent hydroxyethyl starch 130/0.4 and ringer's lactate as priming solutions in patients undergoing isolated open heart valve surgery: A double-blind randomized controlled trial

OBJECTIVES

Colloids are added to the priming solution of the cardiopulmonary bypass (CPB) pump to maintain colloid osmotic pressure and prevent fluid overload. This study aimed to compare the effects of 6% hydroxyethyl starch (HES) 130/0.4 and ringer's lactate (RL) priming solution on patients' outcomes undergoing isolated heart valve surgery with CPB.

METHODS

This randomized clinical trial included one hundred and 20 patients undergoing heart valve surgery, and those were allocated into two groups. Patients in the RL group received 1500 mL of RL, and those in the RL + HES group were given 500 mL of HES and 1000 mL of RL.

RESULTS

The patients' median age was 52 (IQR 42-60) and 50 (IQR 40-61) years in the RL + HES and the RL group, respectively (p = .71). The number of cases that required blood product transfusion in both the operating room and intensive care unit was also significantly higher in the RL + HES group compared to the RL group (RR 2.04, 95% CI 1.50-2.76; p < .01 and RR 1.42, 95% CI 1.01-2.01; p = .05, respectively). Declines in postoperative creatinine levels and platelet counts were higher in the RL + HES compared to the RL group (between-subjects effect p = .007 and p = .038, respectively), while the incidence of acute kidney injury was comparable between groups (RR 0.66, 95% CI 0.13-3.30; p = .55).

CONCLUSIONS

Among patients undergoing heart valve surgery with CPB, 6% HES added to RL for priming compared with only RL increased the risk of the need for blood product transfusion over the hospitalization period.

Bivalirudin anticoagulation for cardiopulmonary bypass during cardiac surgery

INTRODUCTION

Heparin is the primary anticoagulant for cardiopulmonary bypass (CPB) support during cardiac surgery. While widely used, ∼2% of cardiac surgery patients develop heparin-induced thrombocytopenia (HIT) and 4-26% develop heparin resistance. Bivalirudin is an alternative anticoagulant mainly used for percutaneous coronary interventions. Given the challenges associated with heparin anticoagulation, we conducted a review to explore the use of bivalirudin for CPB surgery.

METHODS

PubMed and Embase scoping review included 2 randomized controlled trials, a retrospective comparison study, 3 pilot studies, and 30 case reports. To provide a contemporary series, we searched for articles published from 2010 to 2023. Our review included studies from both adult and pediatric populations.

RESULTS

While data is limited, bivalirudin seems to supply similar effectiveness and safety as heparin for CPB anticoagulation. Across the three comparative studies, the heparin cohorts had a 0-9% mortality rate and 0-27% rate of major bleeding/reoperation compared to a 0-3% mortality and 0-6% major bleeding/reoperation rate for the bivalirudin cohorts. Bivalirudin was successfully used as an anticoagulant in a wide range of CPB surgeries (e.g., heart transplants, ventricular assisted device placements, and valve repairs). Successful patient outcomes were reported with bivalirudin infusion of ∼2 mg/kg/hour, activated clotting time monitoring (target >400 s or 2.5× baseline), use of cardiotomy suctions, minimization of stagnant blood, and post-bypass modified ultrafiltration.

CONCLUSION

Bivalirudin is a safe and effective anticoagulant for CPB, especially for patients with HIT or heparin resistance. Further comparative research is called for to optimize bivalirudin utilization for CPB during cardiac surgery.

What determines outcomes in multivalve reoperations? Effect of patient and surgical complexity

OBJECTIVE

Patient characteristics, risks, and outcomes associated with reoperative multivalve cardiac surgery are poorly characterized. Effect of patient variables and surgical components of each reoperation were evaluated with regard to operative mortality.

METHODS

From January 2008 to January 2022, 2324 patients with previous cardiac surgery underwent 2352 reoperations involving repair or replacement of multiple cardiac valves at Cleveland Clinic. Mean age was 66 ± 14 years. Number of surgical components representing surgical complexity (valve procedures, aortic surgery, coronary artery bypass grafting, and atrial fibrillation procedures) ranged from 2 to 6. Random forest for imbalanced data was used to identify risk factors for operative mortality.

RESULTS

Surgery was elective in 1327 (56%), urgent in 1006 (43%), and emergency in 19 (0.8%). First-time reoperations were performed in 1796 (76%) and 556 (24%) had 2 or more previous operations. Isolated multivalve operations comprised 54% (1265) of cases; 1087 incorporated additional surgical components. Two valves were operated on in 80% (1889) of cases, 3 in 20% (461), and 4 in 0.09% (2). Operative mortality was 4.2% (98 out of 2352), with 1.7% (12 out of 704) for elective, isolated multivalve reoperations. For each added surgical component, operative mortality incrementally increased, from 2.4% for 2 components (24 out of 1009) to 17% for ≥5 (5 out of 30). Predictors of operative mortality included coronary artery bypass grafting, surgical urgency, cardiac, renal dysfunction, peripheral artery disease, New York Heart Association functional class, and anemia.

CONCLUSIONS

Elective, isolated reoperative multivalve surgery can be performed with low mortality. Surgical complexity coupled with key physiologic factors can be used to inform surgical risk and decision making.

Delirium after Cardiac Surgery-A Narrative Review

Postoperative delirium (POD) after cardiac surgery is a well-known phenomenon which carries a higher risk of morbidity and mortality. Multiple patient-specific risk factors and pathophysiologic mechanisms have been identified and therapies have been proposed to mitigate risk of delirium development postoperatively. Notably, cardiac surgery frequently involves the use of an intraoperative cardiopulmonary bypass (CPB), which may contribute to the mechanisms responsible for POD. Despite our greater understanding of these causative factors, a substantial reduction in the incidence of POD remains high among cardiac surgical patients. Multiple therapeutic interventions have been implemented intraoperatively and postoperatively, many with conflicting results. This review article will highlight the incidence and impact of POD in cardiac surgical patients. It will describe some of the primary risk factors associated with POD, as well as anesthetic management and therapies postoperatively that may help to reduce delirium.

Effects of dexmedetomidine on kidney and brain tissue microcirculation and histology in ovine cardiopulmonary bypass: a randomised controlled trial

Cardiac surgery requiring cardiopulmonary bypass is associated with postoperative acute kidney injury and neurocognitive disorders, including delirium. Intra-operative inflammation and/or impaired tissue perfusion/oxygenation are thought to be contributors to these outcomes. It has been hypothesised that these problems may be ameliorated by the highly selective α2 -agonist, dexmedetomidine. We tested the effects of dexmedetomidine on renal and cerebral microcirculatory tissue perfusion, oxygenation and histology in a clinically relevant ovine model. Sixteen sheep were studied while conscious, after induction of anaesthesia and during 2 h of cardiopulmonary bypass. Eight sheep were allocated randomly to receive an intravenous infusion of dexmedetomidine (0.4-0.8 μg.kg-1 .h-1 ) from induction of anaesthesia to the end of cardiopulmonary bypass, and eight to receive an equivalent volume of matched placebo (0.9% sodium chloride). Commencement of cardiopulmonary bypass decreased renal medullary tissue oxygenation in the placebo group (mean (95%CI) 5.96 (4.24-7.23) to 1.56 (0.84-2.09) kPa, p = 0.001), with similar hypoxic levels observed in the dexmedetomidine group (6.33 (5.33-7.07) to 1.51 (0.33-2.39) kPa, p = 0.002). While no differences in kidney function (i.e. reduced creatinine clearance) were evident, a greater incidence of histological renal tubular injury was observed in sheep receiving dexmedetomidine (7/8 sheep) compared with placebo (2/8 sheep), p = 0.041. Graded on a semi-quantitative scale (0-3), median (IQR [range]) severity of histological renal tubular injury was higher in the dexmedetomidine group compared with placebo (1.5 (1-2 [0-3]) vs. 0 (0-0.3 [0-1]) respectively, p = 0.013). There was no difference in cerebral tissue microglial activation (neuroinflammation) between the groups. Dexmedetomidine did not reduce renal medullary hypoxia or cerebral neuroinflammation in sheep undergoing cardiopulmonary bypass.

The effects of pulsatile versus nonpulsatile flow on cerebral pulsatility index, mean flow velocity at the middle cerebral artery, regional cerebral oxygen saturation, cerebral gaseous microemboli counts, and short-term clinical outcomes in patients undergoing congenital heart surgery

Objective

The objective of this retrospective review was to evaluate whether or not pulsatile flow improves cerebral hemodynamics and clinical outcomes in pediatric congenital cardiac surgery patients.

Methods

This retrospective study included 284 pediatric patients undergoing congenital cardiac surgery with cardiopulmonary bypass support utilizing nonpulsatile (n = 152) or pulsatile (n = 132) flow. Intraoperative cerebral gaseous microemboli counts, pulsatility index, and mean blood flow velocity at the right middle cerebral artery were assessed using transcranial Doppler ultrasound. Clinical outcomes were compared between groups.

Results

Patient demographics and cardiopulmonary bypass characteristics between groups were similar. Although the pulsatility index during aortic crossclamping was consistently higher in the pulsatile group (P < .05), a significant degree of pulsatility was also observed in the nonpulsatile group. No significant differences in mean cerebral blood flow velocity, regional cerebral oxygen saturation, or gaseous microemboli counts were observed between the perfusion modality groups. Clinical outcomes, including intubation duration, intensive care unit and hospital length of stay, and mortality within 180 days were similar between groups.

Conclusions

Although the pulsatility index was greater in the pulsatile group, other measures of intraoperative cerebral perfusion and short-term outcomes were similar to the nonpulsatile group. These findings suggest that while pulsatile perfusion represents a safe modality for cardiopulmonary bypass support, its use may not translate into detectably superior clinical outcomes.

Is a hyperosmolar pump prime for cardiopulmonary bypass a risk factor for postoperative delirium? A double blinded randomised controlled trial

Objective: Postoperative delirium (POD) is common after cardiac surgery. We have previously identified plasma sodium concentration and the volume of infused fluids during surgery as possible risk factors. Both are linked to the selection and composition of the pump prime used for cardiopulmonary bypass (CPB). Present study aims to examine whether hyperosmolality increases the risk for POD. Design: Patients ≥65 years (n = 195) scheduled for cardiac surgery were prospectively enrolled into this double blinded randomised clinical trial. Study group received a pump prime containing mannitol and ringer-acetate (966 mOsmol) (n = 98) vs. ringer-acetate (388 mOsmol) (n = 97) in the control group. Postoperative delirium was defined according to DSM-5 criteria based on a test-battery pre- and postoperatively (days 1-3). Plasma osmolality was measured on five occasions and coordinated with the POD assessments. The primary outcome was the POD incidence related to hyperosmolality as the secondary outcome. Results: The incidence of POD was 36% in the study group and 34% in the control group, without intergroup difference (p=.59). The plasma osmolality was significantly higher in the study group, both on days 1 and 3 and after CPB (p<.001). Post hoc analysis indicated that high osmolality levels increased the risk for delirium on day 1 by 9% (odds ratio (OR) 1.09, 95% CI 1.03-1.15) and by 10% on day 3 (OR 1.10, 95% CI 1.04-1.16). Conclusions: Use of a prime solution with high osmolality did not increase the incidence of POD. However, the influence of hyperosmolality as a risk factor for POD warrants further investigation.

Electroencephalography as a tool to predict cerebral oxygen metabolism during deep-hypothermic circulatory arrest in neonates with critical congenital heart disease

Objectives

Recent research suggests that increased cerebral oxygen use during surgical intervention for neonates with congenital heart disease may play a role in the development of postoperative white matter injury. The objective of this study is to determine whether increased cerebral electrical activity correlates with greater decrease of cerebral oxygen saturation during deep hypothermic circulatory arrest.

Methods

Neonates with critical congenital heart disease requiring surgical intervention during the first week of life were studied. All subjects had continuous neuromonitoring with electroencephalography and an optical probe (to quantify cerebral oxygen saturation) during cardiac surgical repair that involved the use of cardiopulmonary bypass and deep hypothermic circulatory arrest. A simple linear regression was used to investigate the association between electroencephalography metrics before the deep hypothermic circulatory arrest period and the change in cerebral oxygen saturation during the deep hypothermic circulatory arrest period.

Results

Sixteen neonates had both neuromonitoring modalities attached during surgical repair. Cerebral oxygen saturation data from 5 subjects were excluded due to poor data quality, yielding a total sample of 11 neonates. A simple linear regression model found that the presence of electroencephalography activity at the end of cooling is positively associated with the decrease in cerebral oxygen saturation that occurs during deep hypothermic circulatory arrest (P < .05).

Conclusions

Electroencephalography characteristics within 5 minutes before the initiation of deep hypothermic circulatory arrest may be useful in predicting the decrease in cerebral oxygen saturation that occurs during deep hypothermic circulatory arrest. Electroencephalography may be an important tool for guiding cooling and the initiation of circulatory arrest to potentially decrease the prevalence of new white matter injury in neonates with critical congenital heart disease.

Hemolysis Precedes Urine Color Change in Patients Undergoing Open-Heart Surgery on Cardiopulmonary Bypass

PURPOSE

Red-colored urine often occurs in patients in the perioperative period who undergo cardiac surgery using cardiopulmonary bypass (CPB). This urine color change has been utilized for approximating hemolysis during CPB without a proven relationship for ongoing hemolysis. This case series study aimed to examine the relationship between plasma free hemoglobin (Hb) levels and quantified measures of urine color.

METHODS

Ten patients were enrolled in this study. Blood and urine were collected for analyses for the following time points: before surgery, two hours after the initiation of CPB, every 30 min during CPB thereafter, and 0, 2, 4, 12, and 24 hours after the completion of CPB. We measured free Hb in plasma and urine using the azide-methemoglobin method. Photographs of urine were obtained, and the luminance of the three basic colors (red/green/blue) was analyzed by quantitative luminance contrast analysis to find a correlation for hemolysis.

RESULTS

Median levels of plasma free Hb were 0.015 (0.010-0.080, n = 10) g/dL at baseline. During the CPB, increases in plasma free Hb levels were measured: median plasma free Hb levels were increased to 0.100 g/dL (0.020-0.240, p = 0.039, vs. baseline, n = 9) at two hours into CPB, median and range, respectively. In contrast, increases in urinary free Hb levels and/or urine color changes were measured only after cessation of CPB in nine patients.

CONCLUSION

Urine color change or elevation of urinary free Hb levels followed the elevation of plasma free Hb levels with considerable delay.

The Year in Coagulation and Transfusion: Selected Highlights from 2022

This is an annual review to cover highlights in transfusion and coagulation in patients undergoing cardiovascular surgery. The goal of this article is to provide readers with a focused summary of the most important transfusion and coagulation topics published in 2022. This includes a discussion covering the management of anemia and red blood cell transfusion, the management of factor Xa inhibitors, updates in coagulation testing, updates in the use of factor concentrates, advances in platelet therapy, advances in anticoagulation management of patients on extracorporeal membrane oxygenation and other forms of mechanical circulatory support, and advances in the diagnosis and management of heparin-induced thrombocytopenia.

Giant Right Coronary Artery Aneurysm in a Patient With Multiple Coronary Artery Aneurysmatic Dilatations

One kind of coronary artery disease that is uncommon is coronary artery aneurysm (CAA). According to angiographic reports, the incidence of coronary artery aneurysms ranges from 1.5% to 4.9%, with a higher frequency in men. A patient with both coronary heart disease and an aneurysm in the right coronary artery (RCA) underwent a successful simultaneous coronary bypass together with an aneurysmal reconstruction procedure.

Cardiac surgery elicits pericardial inflammatory responses that are distinct compared with postcardiopulmonary bypass systemic inflammation

Objectives

Cardiac surgery using cardiopulmonary bypass contributes to a robust systemic inflammatory process. Local intrapericardial postsurgical inflammation is believed to trigger important clinical implications, such as postoperative atrial fibrillation and postsurgical intrathoracic adhesions. Immune mediators in the pericardial space may underlie such complications.

Methods

In this prospective pilot clinical study, 12 patients undergoing isolated coronary artery bypass graft surgery were enrolled. Native pericardial fluid and venous blood samples (baseline) were collected immediately after pericardiotomy. Postoperative pericardial fluid and venous blood samples were collected 48-hours after cardiopulmonary bypass and compared with baseline. Flow cytometry determined proportions of specific immune cells, whereas multiplex analysis probed for inflammatory mediators.

Results

Neutrophils are the predominant cells in both the pericardial space and peripheral blood postoperatively. There are significantly more CD163lo macrophages in blood compared with pericardial effluent after surgery. Although there are significantly more CD163hi macrophages in native pericardial fluid compared with baseline blood, after surgery there are significantly fewer of these cells present in the pericardial space compared with blood. Postoperatively, concentration of interleukin receptor antagonist 6, and interleukin 8 were significantly higher in the pericardial space compared with blood. After surgery, compared with blood, the pericardial space has a significantly higher concentration of matrix metalloproteinase 3, matrix metalloproteinase 8, and matrix metalloproteinase 9. The same trend was observed with transformational growth factor β.

Conclusions

Cardiac surgery elicits an inflammatory response in the pericardial space, which differs from systemic inflammatory responses. Future work should determine whether or not this distinct local inflammatory response contributes to postsurgical complications and could be modified to influence clinical outcomes.

Risk factors for long post-operative hospital stays after cardiopulmonary bypass surgery in full-term neonates

BACKGROUND

Long hospital stays for neonates following cardiac surgery can be detrimental to short- and long-term outcomes. Furthermore, it can impact resource allocation within heart centres' daily operations. We aimed to explore multiple clinical variables and complications that can influence and predict the post-operative hospital length of stay.

METHODS

We conducted a retrospective observational review of the full-term neonates (<30 days old) who had cardiac surgery in a tertiary paediatric cardiac surgery centre - assessment of multiple clinical variables and their association with post-operative hospital length of stay.

RESULTS

A total of 273 neonates were screened with a mortality rate of 8%. The survivors (number = 251) were analysed; 83% had at least one complication. The median post-operative hospital length of stay was 19.5 days (interquartile range 10.5, 31.6 days). The median post-operative hospital length of stay was significantly different among patients with complications (21.5 days, 10.5, 34.6 days) versus the no-complication group (14 days, 9.6, 19.5 days), p < 0.01. Among the non-modifiable variables, gastrostomy, tracheostomy, syndromes, and single ventricle physiology are significantly associated with longer post-operative hospital length of stay. Among the modifiable variables, deep vein thrombosis and cardiac arrest were associated with extended post-operative hospital length of stay.

CONCLUSIONS

Complications following cardiac surgery can be associated with longer hospital stay. Some complications are modifiable. Deep vein thrombosis and cardiac arrest are among the complications that were associated with longer hospital stay and offer a direct opportunity for prevention which may be reflected in better outcomes and shorter hospital stay.

Incidence of Intraoperative Vasoplegic Syndrome in Lung Transplantation

OBJECTIVES

Severe hypotension and low systemic vascular resistance in the setting of adequate cardiac output, known as "vasoplegic syndrome" (VS), is a physiologic disturbance reported in 9% to 44% of cardiac surgery patients. Although this phenomenon is well-documented in cardiac surgery, there are few studies on its occurrence in lung transplantation. The goal of this study was to characterize the incidence of VS in lung transplantation, as well as identify associated risk factors and outcomes.

DESIGN

Retrospective study of single and bilateral lung transplants from April 2013 to September 2021.

SETTING

The study was conducted at an academic hospital.

PARTICIPANTS

Patients ≥18 years of age who underwent lung transplantation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The authors defined VS as mean arterial pressure <65 mmHg, cardiac index ≥2.2 L/min/m2, and ≥30 minutes of vasopressor administration after organ reperfusion. The association between VS and risk factors or outcomes was assessed using t tests, Mann-Whitney U, and chi-square tests. The authors ran multivariate logistic regression models to determine factors independently associated with VS. The incidence of VS was 13.9% (CI 10.4%-18.4%). In the multivariate model, male sex (odds ratio 2.85, CI 1.07-7.58, p = 0.04) and cystic fibrosis (odds ratio 5.76, CI 1.43-23.09, p = 0.01) were associated with VS.

CONCLUSIONS

The incidence of VS in lung transplantation is comparable to that of cardiac surgery. Interestingly, male sex and cystic fibrosis are strong risk factors. Identifying lung transplant recipients at increased risk of VS may be crucial to anticipating intraoperative complications.

Haemodynamic effects of prophylactic post-operative hydrocortisone following cardiopulmonary bypass in neonates undergoing cardiac surgery

Multiple studies have endeavoured to define the role of steroids in paediatric congenital heart surgery; however, steroid utilisation remains haphazard. In September, 2017, our institution implemented a protocol requiring that all neonates undergoing cardiac surgery with the use of cardiopulmonary bypass receive a five-day post-operative hydrocortisone taper. This single-centre retrospective study was designed to test the hypothesis that routine post-operative hydrocortisone administration reduces the incidence of capillary leak syndrome, leads to favourable postoperative fluid balance, and less inotropic support in the early post-operative period. Data were gathered on all term neonates who underwent cardiac surgery with the use of bypass between September, 2015 and 2019. Subjects who were unable to separate from bypass, required long-term dialysis, or long-term mechanical ventilation were excluded. Seventy-five patients met eligibility criteria (non-hydrocortisone group = 52; hydrocortisone group = 23). For post-operative days 0-4, we did not observe a significant difference in net fluid balance or vasoactive inotropic score between study groups. Similarly, we saw no major difference in secondary clinical outcomes (post-operative duration of mechanical ventilation, ICU/hospital length of stay, and time from surgery to initiation of enteral feeds). In contrast to prior analyses, our study was unable to demonstrate a significant difference in net fluid balance or vasoactive inotropic score with the administration of a tapered post-operative hydrocortisone regimen. Similarly, we saw no effect on secondary clinical outcomes. Further long-term randomised control studies are necessary to validate the potential clinical benefit of utilising steroids in paediatric cardiac surgery, especially in the more fragile neonatal population.

Management of Giant Pulmonary Artery Aneurysm with Quadricuspid Valve Stenosis

The pulmonary artery aneurysm (PAA) is a rare disease with no well-defined guidelines about the diagnostic criteria and its management. In fact, the indications for surgical treatment and the type of surgical approach are not clear. However, in case of giant PAAs with hypertension and pulmonary valve abnormalities, surgery should be considered as an effective and safe approach to prevent dissections or ruptures. In this report, we describe a successful case of surgical repair, using a Bioconduit with a pericardial patch to recreate the pulmonary artery bifurcation in a 72-year-old male with aneurysm of the pulmonary artery (max diameter: 72 mm), associated with quadricuspid pulmonary valve stenosis and pulmonary hypertension. The procedure was uncomplicated and the follow-up computed tomography scan at 4 months showed correct positioning of the graft with no sign of contrast leakage.

Recommendations for centers performing pediatric heart surgery in the United States

Care and outcomes for the more than 40,000 patients undergoing pediatric and congenital heart surgery in the United States annually are known to vary widely. While consensus recommendations have been published across numerous fields as one mechanism to promote a high level of care delivery across centers, it has been more than two decades since the last pediatric heart surgery recommendations were published in the United States. More recent guidance is lacking, and collaborative efforts involving the many disciplines engaged in caring for these children have not been undertaken to date. The present initiative brings together professional societies spanning numerous care domains and congenital cardiac surgeons, pediatric cardiologists, nursing, and other healthcare professionals from diverse programs around the country to develop consensus recommendations for United States centers. The focus of this initial work is on pediatric heart surgery, and it is recommended that future efforts focus in detail on the adult congenital population. We describe the background, rationale, and methodology related to this collaborative effort, and recommendations put forth for Essential Care Centers (essential services necessary for any program), and Comprehensive Care Centers (services to optimize comprehensive and high-complexity care), encompassing structure, process, and outcome metrics across 14 domains.

Mesenchymal Stromal Cell Delivery Via Cardiopulmonary Bypass Provides Neuroprotection in a Juvenile Porcine Model

Oxidative/inflammatory stresses due to cardiopulmonary bypass (CPB) cause prolonged microglia activation and cortical dysmaturation, thereby contributing to neurodevelopmental impairments in children with congenital heart disease (CHD). This study found that delivery of mesenchymal stromal cells (MSCs) via CPB minimizes microglial activation and neuronal apoptosis, with subsequent improvement of cortical dysmaturation and behavioral alteration after neonatal cardiac surgery. Furthermore, transcriptomic analyses suggest that exosome-derived miRNAs may be the key drivers of suppressed apoptosis and STAT3-mediated microglial activation. Our findings demonstrate that MSC treatment during cardiac surgery has significant translational potential for improving cortical dysmaturation and neurological impairment in children with CHD.

Perioperative hemostatic management of patients with type A aortic dissection

Coagulopathy is common in patients undergoing thoracic aortic repair for Stanford type A aortic dissection. Non-critical administration of blood products may adversely affect the outcome. It is therefore important to be familiar with the pathologic conditions that lead to coagulopathy in complex cardiac surgery. Adequate care of these patients includes the collection of the medical history regarding the use of antithrombotic and anticoagulant drugs, and a sophisticated diagnosis of the coagulopathy with viscoelastic testing and subsequently adapted coagulation therapy with labile and stable blood products. In addition to the above-mentioned measures, intraoperative blood conservation measures as well as good interdisciplinary coordination and communication contribute to a successful hemostatic management strategy.

Influence of minimal invasive extracorporeal circuits on dialysis dependent patients undergoing cardiac surgery

INTRODUCTION

Cardiac surgery in patients on chronic renal dialysis is associated with significant morbidity and mortality. Minimally invasive extracorporeal circuits (MiECC) have shown a positive impact on patient outcome in different high-risk populations. This retrospective study compares the outcome of these high-risk patients undergoing heart surgery either with a MiECC or a conventional extracorporeal circulation (CECC).

METHODS

This is a single-center experience including 131 consecutive dialysis dependent patients undergoing cardiac surgery between January 2006 and December 2016. A propensity score matching was employed leaving 30 matched cases in each group.

RESULTS

After propensity score matching the 30-day mortality was significantly lower in the MiECC group (n = 3 (10%) vs n = 10 (33%) in the CECC group, p = .028). Further, intraoperative transfused units of packed red blood cells were lower in the MiECC group (1.4 ± 1.8 units vs 2.8 ± 1.7, p < .001).

CONCLUSIONS

There are evident advantages to using MiECC in dialysis dependent patients, especially regarding mortality. These findings necessitate additional research in MiECC usage in high-risk populations.

Diffuse Optical Monitoring of Cerebral Hemodynamics and Oxygen Metabolism during and after Cardiopulmonary Bypass: Hematocrit Correction and Neurological Vulnerability

Cardiopulmonary bypass (CPB) provides cerebral oxygenation and blood flow (CBF) during neonatal congenital heart surgery, but the impacts of CPB on brain oxygen supply and metabolic demands are generally unknown. To elucidate this physiology, we used diffuse correlation spectroscopy and frequency-domain diffuse optical spectroscopy to continuously measure CBF, oxygen extraction fraction (OEF), and oxygen metabolism (CMRO2) in 27 neonatal swine before, during, and up to 24 h after CPB. Concurrently, we sampled cerebral microdialysis biomarkers of metabolic distress (lactate-pyruvate ratio) and injury (glycerol). We applied a novel theoretical approach to correct for hematocrit variation during optical quantification of CBF in vivo. Without correction, a mean (95% CI) +53% (42, 63) increase in hematocrit resulted in a physiologically improbable +58% (27, 90) increase in CMRO2 relative to baseline at CPB initiation; following correction, CMRO2 did not differ from baseline at this timepoint. After CPB initiation, OEF increased but CBF and CMRO2 decreased with CPB time; these temporal trends persisted for 0-8 h following CPB and coincided with a 48% (7, 90) elevation of glycerol. The temporal trends and glycerol elevation resolved by 8-24 h. The hematocrit correction improved quantification of cerebral physiologic trends that precede and coincide with neurological injury following CPB.

Angiotensin-II for vasoplegia following cardiac surgery

INTRODUCTION

The objective of this study was to describe the implementation and outcomes of a protocol outlining angiotensin-II utilization for vasoplegia following cardiac surgery.

METHODS

This was a retrospective chart review at a single-center university hospital. Included patients received angiotensin-II for vasoplegia refractory to standard interventions, including norepinephrine 20 mcg/min and vasopressin 0.04 units/min, following cardiac surgery between April 2021 and April 2022.

RESULTS

30 patients received angiotensin-II for refractory vasoplegia. Adjunctive agents at angiotensin-II initiation included corticosteroids (26 patients; 87%), epinephrine (26 patients; 87%), dobutamine (17 patients; 57%), dopamine (9 patients; 30%), milrinone (2 patients; 7%), and hydroxocobalamin (4 patients; 13%). At 3 hours, the median mean arterial pressure increased from baseline (70 vs 61.5 mmHg, p = .0006). Median norepinephrine doses at angiotensin-II initiation, 1 hour, 3 hours, and angiotensin-II discontinuation were 0.22, 0.16 (p = .0023), 0.10 (p < .0001), and 0.07 (p < .0001) mcg/kg/min. Median dobutamine doses decreased throughout angiotensin-II infusion from eight to six mcg/kg/min (p = .0313). Other vasoactive medication doses were unchanged. Three patients (10%) subsequently received hydroxocobalamin. Thirteen (43.3%) and five (16.7%) patients experienced mortality by day 28 and venous or arterial thrombosis events, respectively.

CONCLUSIONS

The administration of angiotensin-II to vasoplegic patients following cardiac surgery was associated with increased mean arterial pressure, reduced norepinephrine dosages, and reduced dobutamine dosages.

Effects of norepinephrine infusion during cardiopulmonary bypass on perioperative changes in lactic acid level (Norcal)

INTRODUCTION

Hyperlactatemia, a problem reported in up to 30% of cardiac surgery patients, results from excessive production of or decreased clearance of lactate. It is typically a symptom of tissue hypoperfusion and may be associated with the prevalence of postoperative acute mesenteric ischemia and renal failure, or prolonged intensive care unit (ICU) and hospital stay, and increased 30-day mortality.

METHODS AND MEASUREMENTS

Eighty cardiac surgery patients using cardiopulmonary bypass (CPB) were randomly assigned into either a placebo (n = 39) or norepinephrine 0.05-0.2 µg/kg/min (n = 41) as well as norepinephrine boluses during CPB to maintain mean arterial blood pressure (MAP) at 65 to 80 mm Hg. Patient assignments were done after receiving ethical approval to proceed. The primary result was the perioperative changes in lactic acid level. Secondary findings were also recorded, including hemodynamic variables, the incidence of vasoplegia, intraoperative hypotension, myocardial ischemia, the need for vasopressor support, postoperative complications, and mortality.

RESULTS

The peak levels and perioperative changes in blood lactate during the first 24 postoperative hours, the number of patients who experienced early hyperlactatemia on admission to the ICU (Placebo: 46.2%, Norepinephrine: 51.2%, p = .650), vasoplegia, hemodynamic changes, incidences of intraoperative hypotension, myocardial ischemia, postoperative complications, and mortality rates were similar in the two groups. Patients in the norepinephrine group received lower intraoperative rescue norepinephrine boluses to maintain the target MAP (p = .039) and had higher MAP values during the CPB and intraoperative blood loss [mean difference [95% confidence interval]; 177 [20.9-334.3] ml, p = .027].

CONCLUSION

norepinephrine and placebo infusions during the CPB with the maintenance of MAP from 65 to 80 mmHg had comparative effects on the changes in blood lactate and incidence of vasoplegia after cardiac surgery. Norepinephrine infusion maintained higher MAP values during the CPB.

The effect of relative cerebral hyperperfusion during cardiac surgery with cardiopulmonary bypass to delayed neurocognitive recovery

OBJECTIVE

Delayed neurocognitive recovery (dNCR) remains a common complication after surgery and the incidence of it is determined 30-80% after cardiac surgery with cardiac bypass (CPB) in eldery patients. Many researchers have identified that neuropsychological complications emerge from insufficient cerebral perfusion. Relative cerebral hyperperfusion also disrupts cerebral autoregulation and might play a significant role in dNCR development. The aim of this study is to determine hyperperfusion in the middle cerebral artery during CPB influence to dNCR development and brain biomarker glial fibrillary acidic protein (GFAP) impact in diagnosing dNCR.

DESIGNS AND METHODS

This prospective - case control study included patients undergoing elective coronary artery bypass grafting or/and valve surgery with CPB. For cognitive evaluation 101 patients completed Addenbrooke's cognitive examination - ACE-III. To determine mild cognitive dysfunction, cut - off 88 was chosen. Mean BFV was monitored with transcranial Doppler ultrasonography (TCD) and performed before surgery, after induction of anaesthesia, during CPB and after surgery. Preoperative BFV was converted to 100% and used as a baseline. The percentage change of cerebral blood flow velocity during CPB was calculated from baseline. Patients with decreased blood flow velocity were included for further investigation. To measure glial fibrillary acidic protein, blood samples were collected after anaesthesia induction, 24 and 48 h after the surgery. According to the ACE-III test results, patients with relative hyperperfusion were divided into two groups: with Delayed neurocognitive recovery and without dNCR (non-dNCR group).

RESULTS

101 patients were examined, 67 (69.1%) men and 29 (29.9%) women, age 67.9 (SD 9.2) Increased percentage of BFV was determined for 40 (39.60%) patients. There were no differences in sex, haematocrit, paCO2, aortic cross-clamping or CPB time between the two groups. Percentage change of BFV was 105.60% in the non-dNCR group and 132.29% in the dNCR group, p = .033. Patients who developed dNCR in the early post-surgical period were significantly older, p < .001 and had a lower baseline of BFV, p = .004. GFAP concentration significantly increased in the dNCR group 48 hours after surgery, compared to the non-dNCR group, p = .01.

CONCLUSIONS

Relative hyperperfusion during CPB may cause dNCR. Elderly patients are sensitive to blood flow velocity acceleration during CPB. GFAP concentration increased 48 h after surgery in dNCR group but did not have any connection with risk factors.

Exogenous nitric oxide delivery protects against cardiopulmonary bypass-associated acute kidney injury: Histologic and serologic evidence from an ovine model

OBJECTIVE

Several human studies have associated nitric oxide administration via the cardiopulmonary bypass circuit with decreased incidence of cardiopulmonary bypass-associated acute kidney injury, but histopathologic and serologic evidence of nitric oxide efficacy for acute kidney injury attenuation are lacking.

METHODS

By using a survival ovine model (72 hours), acute kidney injury was induced by implementing low-flow cardiopulmonary bypass for 2 hours, followed by full-flow cardiopulmonary bypass for 2 hours. The nitric oxide cohort (n = 6) received exogenous nitric oxide through the cardiopulmonary bypass circuit via the oxygenator, and the control group (n = 5) received no nitric oxide. Serial serologic biomarkers and renal histopathology were obtained.

RESULTS

Baseline characteristics (age, weight) and intraoperative parameters (cardiopulmonary bypass time, urine output, heart rate, arterial pH, and lactate) were equivalent (P > .10) between groups. Postoperatively, urine output, heart rate, respiratory rate, and peripheral arterial saturation were equivalent (P > .10) between groups. Post-cardiopulmonary bypass creatinine elevations from baseline were significantly greater in the control group versus the nitric oxide group at 16, 24, and 48 hours (all P < .05). Histopathologic evidence of moderate/severe acute kidney injury (epithelial necrosis, tubular slough, cast formation, glomerular edema) occurred in 60% (3/5) of the control group versus 0% (0/6) of the nitric oxide group. Cortical tubular epithelial cilia lengthening (a sensitive sign of cellular injury) was significantly greater in the control group than in the nitric oxide group (P = .012).

CONCLUSIONS

In a survival ovine cardiopulmonary bypass model, nitric oxide administered with cardiopulmonary bypass demonstrated serologic and histologic evidence of renal protection from acute kidney injury. These results provide insight into 1 potential mechanism for cardiopulmonary bypass-associated acute kidney injury and supports continued study of nitric oxide via cardiopulmonary bypass circuit for prevention of acute kidney injury.

Population pharmacokinetic model-based dosing proposal for ampicillin prophylaxis in cardiac surgery patients with cardiopulmonary bypass

The aim of this study was to describe and quantify pharmacokinetics of ampicillin used prophylactically in cardiac surgery both with and without cardiopulmonary bypass (CPB) using population pharmacokinetic analysis in order to propose an optimal dosing strategy. Adult patients undergoing cardiac surgery and treated with prophylactic dose of 2 g ampicillin were enrolled to this prospective study. Blood samples were collected according to the study protocol and ampicillin plasma concentrations were measured using HPLC/UV system. A three-stage population pharmacokinetic model using nonlinear mixed-effects modelling approach was developed. Totally 273 blood samples obtained from 20 patients undergoing cardiac surgery with the use of the CPB and 20 patients without CPB use were analyzed. Two-comparmental model best fits ampicillin concentration-time data. Mean ± SD body weight-normalized ampicillin central and peripheral volume of distribution was 0.12 ± 0.02 L/kg and 0.15 ± 0.03 L/kg, respectively, while mean ± SD ampicillin clearance in typical patient with eGFR of 1.5 mL/s/1.73 m2 was 1.17 ± 0.05 L/h. The use of CPB did not significantly affect the pharmacokinetics of ampicillin. When administering 2 g of ampicillin before surgery, an additional dose should be administered to reach the PK/PD target of fT > MIC = 50% if the operation lasts longer than 430 min in patients with moderate to severe renal impairment, 320 min in patients with mild renal impairment, 220 min in patients with normal renal function status or 140 min in patients with an augmented renal clearance.

Alterations to Kidney Physiology during Cardiopulmonary Bypass-A Narrative Review of the Literature and Practical Remarks

INTRODUCTION

According to different authors, cardiac surgery-associated acute kidney injury (CSA-AKI) incidence can be as high as 20-50%. This complication increases postoperative morbidity and mortality and impairs long-term kidney function in some patients. This review aims to summarize current knowledge regarding alterations to renal physiology during cardiopulmonary bypass (CPB) and to discuss possible nephroprotective strategies for cardiac surgeries. Relevant sections: Systemic and renal circulation, Vasoactive drugs, Fluid balance and Osmotic regulation and Inflammatory response.

CONCLUSIONS

Considering the available scientific evidence, it is concluded that adequate kidney perfusion and fluid balance are the most critical factors determining postoperative kidney function. By adequate perfusion, one should understand perfusion with proper oxygen delivery and sufficient perfusion pressure. Maintaining the fluid balance is imperative for a normal kidney filtration process, which is essential for preserving the intra- and postoperative kidney function.

FUTURE DIRECTIONS

The review of the available literature regarding kidney function during cardiac surgery revealed a need for a more holistic approach to this subject.

Use of cardiopulmonary bypass machine in intensive care unit as a short term mechanical circulatory support for recovery of cardiac function

INTRODUCTION

Extracorporeal Membrane Oxygenation (ECMO) is used as a bridge to recovery of cardiac function following completion of congenital cardiac surgeries where there is failure to wean from cardiopulmonary bypass (CPB) or severe low cardiac output states in the post operative periods. Although ECMO is a well-established form of mechanical circulatory support, the associated cost can be a huge financial burden on families. We are an ECMO center and use the same in post operative congenital cardiac surgeries for mechanical cardiovascular support if needed. However, a significant proportion of the children, whom we operate, are funded by government aides. The resources are limited in such circumstances. If needed, we use the same CPB circuit and cannulae used in the Operating Room (OR) and support them at a significantly lower cost compared to ECMO.

METHODS

We report our experience of using conventional CPB machine as a short-term bridge to recovery of cardiac function in Intensive Care Unit where there was limitation of funds. Essentially same CPB circuit with roller pump is retained, by omitting cardiotomy suckers. We use D901 Lilliput 1 Oxygenator (Sorin, Italy) for children <5 kg and D902 Lilliput 2 (Sorin, Italy) Oxygenator for children >5 Kg.

RESULTS

We supported nine patients on CPB between March 2019 and December 2021. During this time, 1392 congenital cardiac surgeries were performed. We could wean off three patients (33.3%) and discharge two patients (22.2%). Our support time ranged from 21 h to 60 h with a median of 48 h. Beyond 48 h of support, we experienced several CPB induced complications in our cohort.

CONCLUSION

In resource-limited settings, conventional CPB machines can be used for short-term cardiac support. Although results may not be comparable to using ECMO, some patients can be definitely salvaged, who would otherwise die in the absence of institution of mechanical circulatory support.

Pulmonary Vasodilator and Inodilator Drugs in Cardiac Surgery: A Systematic Review With Bayesian Network Meta-Analysis

OBJECTIVE

The authors performed a systematic review to evaluate the effect of pharmacologic therapy on pulmonary hypertension in the perioperative setting of elective cardiac surgery (PROSPERO CRD42023321041).

DESIGN

Systematic review of randomized controlled trials with a Bayesian network meta-analysis.

SETTING

The authors searched biomedical databases for randomized controlled trials on the perioperative use of inodilators and pulmonary vasodilators in adult cardiac surgery, with in-hospital mortality as the primary outcome and duration of ventilation, length of stay in the intensive care unit, stage 3 acute kidney injury, cardiogenic shock requiring mechanical support, and change in mean pulmonary artery pressure as secondary outcomes.

PARTICIPANTS

Twenty-eight studies randomizing 1,879 patients were included.

INTERVENTIONS

Catecholamines and noncatecholamine inodilators, arterial pulmonary vasodilators, vasodilators, or their combination were considered eligible interventions compared with placebo or standard care.

MEASUREMENTS AND MAIN RESULTS

Ten studies reported in-hospital mortality and assigned 855 patients to 12 interventions. Only inhaled prostacyclin use was supported by a statistically discernible improvement in mortality, with a number-needed-to-treat estimate of at least 3.3, but a wide credible interval (relative risk 1.26 × 10-17 - 0.7). Inhaled prostacyclin and nitric oxide were associated with a reduction in intensive care unit stay, and none of the included interventions reached a statistically evident difference compared to usual care or placebo in the other secondary clinical outcomes.

CONCLUSIONS

Inhaled prostacyclin was the only pharmacologic intervention whose use is supported by a statistically discernible improvement in mortality in the perioperative cardiac surgery setting as treatment of pulmonary hypertension. However, available evidence has significant limitations, mainly the low number of events and imprecision.

Hydroxocobalamin Versus Methylene Blue for the Treatment of Vasoplegic Shock Associated With Cardiopulmonary Bypass

OBJECTIVES

To compare changes in vasopressor requirements and hemodynamic responses after hydroxocobalamin or methylene blue administration for vasoplegic shock (VS).

DESIGN

Retrospective cohort analysis.

SETTING

Single-center, academic medical center.

PATIENTS

Cardiothoracic surgery adult patients.

INTERVENTIONS

Hydroxocobalamin or methylene blue.

MEASUREMENTS

The primary outcome was a change in vasopressor requirements over the first 24 hours (1, 3, 6, 12, and 24 hours) after hydroxocobalamin or methylene blue initiation. Secondary outcomes included changes in mean arterial pressure (MAP), systemic vascular resistance, and lactate.

MAIN RESULTS

A total of 120 adult patients who received hydroxocobalamin (n = 77) or methylene blue (n = 43) were included. Vasopressor requirements at baseline were 0.34 µg/kg/min (95% CI 0.28-0.4) norepinephrine equivalent (NEE) in the hydroxocobalamin group, and 0.59 µg/kg/min (95% CI 0.52-0.66) NEE in the methylene blue group; p < 0.001. Vasopressor requirements decreased significantly at each time point within each group (hour 1 mean [95% CI] NEE, hydroxocobalamin 0.27 µg/kg/min [0.21-0.33]; methylene blue 0.44 µg/kg/min [0.38-0.51]; p < 0.001). The mean MAP at baseline was 65 mmHg (95% CI 63-67) in the hydroxocobalamin group, and 57 mmHg (95% CI 54-59) in the methylene blue group; p < 0.001. The mean MAP increased significantly from baseline at each time point within each group (hour 1 mean [95% CI] hydroxocobalamin 73 mmHg [71-75]; methylene blue 67 mmHg [65-70]; p < 0.001). After adjusting for baseline characteristics, a significantly greater reduction in vasopressor requirements and an increase in MAP were noted in the hydroxocobalamin group compared with the methylene blue group.

CONCLUSIONS

Hydroxocobalamin was associated with a greater reduction in vasopressor requirements than methylene blue in treating VS associated with cardiopulmonary bypass.

Impact of perfusion method on perioperative red blood cell transfusions and new-onset postoperative atrial fibrillation in mitral valve surgery patients

INTRODUCTION

Red blood cell (RBC) transfusions are common in cardiac surgery and reportedly associated with increased mortality and morbidity, including increased risk of postoperative new-onset atrial fibrillation (NOAF). The aim of this study was to compare minimal invasive extracorporeal circulation (MiECC) and conventional extracorporeal circulation (CECC) in terms of RBC transfusions and the incidence of NOAF in mitral valve surgery.

METHODS

The study population consisted of 89 MiECC and 169 CECC patients undergoing mitral valve surgery as an isolated procedure (80.6% of the patients) or in combination with coronary artery bypass grafting (19.4% of patients). 79.4% of the patients were male and the mean age was 62.1 years.

RESULTS

30.0% of patients aged < 65 years and 48.1% of patients aged ≥ 65 years needed RBC transfusion. The overall need for RBC transfusions did not differ between the treatment groups. Among patients < 65 years of age transfusions of ≥ 3 units were less frequent in MiECC than in CECC patients (OR 0.31, 95% CI 0.10-0.98, p = 0.045). The overall incidence of NOAF was 41.8% with no significant difference between MiECC and CECC groups. Red blood cell transfusions were associated with an increased risk of NOAF in an unadjusted analysis but not after adjustment for age and sex (OR 1.25, 95% CI 0.64-2.43, p = 0.515).

CONCLUSIONS

In mitral valve surgery MiECC compared to CECC was associated with less need of RBC units and platelets, particularly in patients aged < 65 years. Use of RBC transfusions was associated with increased risk of NOAF significantly only in unadjusted analysis.

Improving Outcomes for Infants After Cardiopulmonary Bypass Surgery for Congenital Heart Disease: A Commentary on Recent Randomized Controlled Trials

The recent NITRIC and STRESS trials demonstrate opportunities to perform pragmatic large randomized trials in congenital heart disease. We discuss lessons learnt from these trials which can inform future trial design and conduct in the field of pediatric heart surgery.

A Deep Dive Into Retroesophageal Major Aortopulmonary Collateral Arteries

Background: The anatomy of major aortopulmonary collateral arteries (MAPCAs) can be highly variable with regard to number, anatomic origin, course, and relationship to the native pulmonary arteries. Some MAPCAs travel behind the esophagus (retroesophageal) and bronchus before entering the lung parenchyma. The purpose of this paper was to review the anatomy, physiology, and surgical characteristics of retroesophageal MAPCAs. Methods: This manuscript summarizes the data from a series of three papers that have focused on the subject of retroesophageal MAPCAs from our institution over the past ten years. Results: Two-thirds of patients evaluated had a retroesophageal MAPCA identified at surgery. Retroesophageal major aortopulmonary collateral arteries (REMs) were more common with a left arch (77%) compared with a right arch (53%). Of all REMs evaluated, 83% were single supply, 13% were dual supply with an inadequate connection, and 4% were dual supply with an adequate connection. Based on these findings, 96% of retroesophageal MAPCAs were unifocalized. Follow-up catheterization was performed at a median of 17 months after surgery; 75% of unifocalized MAPCAs were widely patent, 20% were patent but stenotic, and 5% were occluded. Conclusions: The data demonstrate that retroesophageal MAPCAs are relatively common and almost always require unifocalization. At mid-term follow-up, 95% of unifocalized MAPCAs were found to be patent.

Intraoperative hemodynamics and risk of cardiac surgery-associated acute kidney injury: An observation study and a feasibility clinical trial

Targeting greater pump flow and mean arterial pressure (MAP) during cardiopulmonary bypass (CPB) could potentially alleviate renal hypoxia and reduce the risk of postoperative acute kidney injury (AKI). Therefore, in an observational study of 93 patients undergoing on-pump cardiac surgery, we tested whether intraoperative hemodynamic management differed between patients who did and did not develop AKI. Then, in 20 patients, we assessed the feasibility of a larger-scale trial in which patients would be randomized to greater than normal target pump flow and MAP, or usual care, during CPB. In the observational cohort, MAP during hypothermic CPB averaged 68.8 ± 8.0 mmHg (mean ± SD) in the 36 patients who developed AKI and 68.9 ± 6.3 mmHg in the 57 patients who did not (p = 0.98). Pump flow averaged 2.4 ± 0.2 L/min/m2 in both groups. In the feasibility clinical trial, compared with usual care, those randomized to increased target pump flow and MAP had greater mean pump flow (2.70 ± 0.23 vs. 2.42 ± 0.09 L/min/m2 during the period before rewarming) and systemic oxygen delivery (363 ± 60 vs. 281 ± 45 mL/min/m2 ). Target MAP ≥80 mmHg was achieved in 66.6% of patients in the intervention group but in only 27.3% of patients in the usual care group. Nevertheless, MAP during CPB did not differ significantly between the two groups. We conclude that little insight was gained from our observational study regarding the impact of variations in pump flow and MAP on the risk of AKI. However, a clinical trial to assess the effects of greater target pump flow and MAP on the risk of AKI appears feasible.

Cardiac surgery-Associated acute kidney injury - A narrative review

Cardiac Surgery-Associated Acute Kidney Injury (CSA-AKI) is a serious complication seen in approximately 20-30% of cardiac surgery patients. The underlying pathophysiology is complex, often involving both patient- and procedure related risk factors. In contrast to AKI occurring after other types of major surgery, the use of cardiopulmonary bypass comprises both additional advantages and challenges, including non-pulsatile flow, targeted blood flow and pressure as well as the ability to manipulate central venous pressure (congestion). With an increasing focus on the impact of CSA-AKI on both short and long-term mortality, early identification and management of high-risk patients for CSA-AKI has evolved. The present narrative review gives an up-to-date summary on definition, diagnosis, underlying pathophysiology, monitoring and implications of CSA-AKI, including potential preventive interventions. The review will provide the reader with an in-depth understanding of how to identify, support and provide a more personalized and tailored perioperative management to avoid development of CSA-AKI.

Quantitative electroencephalography predicts postoperative delirium in cardiac surgical patients after cardiopulmonary bypass: a prospective observational study

Objective

Despite its frequency and associated negative effect, delirium remains poorly recognized in postoperative patients after ICU admission, especially among those who have undergone cardiac surgery with cardiopulmonary bypass. Postoperative delirium is triggered by a wide variety of acute medical conditions associated with impaired neuronal network connectivity. The lack of objective biomarkers primarily hinders the early detection of delirium. Seeking early biomarkers for tracking POD could potentially assist in predicting the onset of delirium and assessing the severity of delirium and response to interventions.

Methods

QEEGs were taken from 46 sedated postoperative patients, with 24 of them having undergone cardiac surgery. The assessment of delirium was performed twice daily using the Confusion Assessment Method for the ICU (CAM-ICU) to screen for postoperative delirium (POD). QEEG data were interpreted clinically by neurophysiologists and processed by open-source EEGLAB to identify features in patients who had or did not have POD after cardiac or non-cardiac surgery.

Results

The incidence of delirium in patients after undergoing cardiac surgery was nine times greater than in those after non-cardiac surgeries (41.7% vs. 4.5%; p = 0.0046). Patients with delirium experienced longer use of mechanical ventilation (118 h (78,323) compared to 20 h (18,23); p < 0.0001) and an extended ICU length of stay (7 days (6, 20) vs. 2 days (2, 4); p < 0.0001). The depth of anesthesia, as measured by RASS scores (p = 0.3114) and spectral entropy (p = 0.1504), showed no significant difference. However, notable differences were observed between delirious and non-delirious patients in terms of the amplitude-integrated EEG (aEEG) upper limit, the relative power of the delta band, and spectral edge frequency 95 (SEF95) (p = 0.0464, p = 0.0417, p = 0.0337, respectively).

Conclusion

In a homogenous population of sedated postoperative patients, robust qEEG parameters strongly correlate with delirium and could serve as valuable biomarkers for early detection of delirium and assist in clinical decision-making.

NO Addition during Gas Oxygenation Reduces Liver and Kidney Injury during Prolonged Cardiopulmonary Bypass

Objective. To evaluate the effect of NO added to the sweep gas of the oxygenator during cardiopulmonary bypass (CPB) on the liver and kidneys in pigs. Methods. An experiment was carried out on 10 pigs undergoing cardiac surgery using CPB. NO was added to the sweep gas of the oxygenator at a concentration of 100 ppm for the animals in the experimental group (CPB-NO, n = 5). Animals in the control group (CPB-contr, n = 5) did not receive NO in the sweep gas of the oxygenator. The CPB lasted 4 h, followed by postoperative monitoring for 12 h. To assess the injury to the liver and kidneys, the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, creatinine, and neutrophil gelatinase-associated lipocalin (NGAL) were determined initially, at weaning from the CPB, and 6 and 12 h after weaning from the CPB. The glomerular filtration rate (GFR) was evaluated initially, at weaning from the CPB, and 6 and 12 h after weaning from the CPB. A pathomorphological study of the liver and kidneys was performed using semiquantitative morphometry. Results. The long four-hour period of CPB deliberately used in our experiment caused liver and kidney injury. In the CPB-contr group, an increase in the ALT concentration was found: 43 (34; 44) U/L at baseline to 82 (53; 99) U/L 12 h after CPB, p < 0.05. The AST concentration in the CPB-contr group increased from 25 (17; 26) U/L at baseline to 269 (164; 376) U/L 12 h after CPB, p < 0.05. We found no significant increase in the ALT and AST concentrations in the CPB-NO group. There were no significant differences in ALT and AST concentrations between the CPB-NO and CPB-contr groups at all the study time-points. In the CPB-contr group, an increase in the creatinine level was found from 131 (129; 133) µmol/L at baseline to 273 (241; 306) µmol/L 12 h after CPB, p < 0.05. We found no significant increase in creatinine level in the CPB-NO group. Creatinine levels in the CPB-NO group were significantly lower than in the CPB-contr group 12 h after weaning from CPB: 183 (168; 196) vs. 273 (241; 306) µmol/L; p = 0.008. The GFR in the CPB-NO group was significantly higher than in the CPB-contr group 6 h after weaning from CPB: 78.9 (77.8; 82.3) vs. 67.9 (62.3; 69.2) mL/min; p = 0.016. GFR was significantly higher in the CPB-NO group than in the CPB-contr group 12 h after weaning from CPB: 67.7 (65.5; 68.0) vs. 50.3 (48.7; 54.9) mL/min; p = 0.032. We found no significant differences between the study groups in the level of NGAL. We found several differences between the groups in the pathomorphological study. Conclusions. NO added to the sweep gas of the oxygenator reduces creatinine levels and increases GFR during prolonged CPB injury. Further research is required.

Biochemical Changes in Cardiopulmonary Bypass in Cardiac Surgery: New Insights

Patients undergoing coronary revascularization with extracorporeal circulation or cardiopulmonary bypass (CPB) may develop several biochemical changes in the microcirculation that lead to a systemic inflammatory response. Surgical incision, post-CPB reperfusion injury and blood contact with non-endothelial membranes can activate inflammatory signaling pathways that lead to the production and activation of inflammatory cells, with cytokine production and oxidative stress. This inflammatory storm can cause damage to vital organs, especially the heart, and thus lead to complications in the postoperative period. In addition to the organic pathophysiology during and after the period of exposure to extracorporeal circulation, this review addresses new perspectives for intraoperative treatment and management that may lead to a reduction in this inflammatory storm and thereby improve the prognosis and possibly reduce the mortality of these patients.

Giant Pancreatic Pseudocyst after Coronary Artery Bypass Graft in a Hemodialysis Patient: A Case Report

End-stage renal disease (ESRD) patients have a high prevalence of coronary artery disease, and coronary artery bypass graft (CABG) is one of the essential treatments. ESRD patients undergoing CABG surgery have an increased risk of postoperative complications, including acute pancreatitis. Here, we present the unique case of an exceptionally large pancreatic pseudocyst caused by pancreatitis in an ESRD patient after CABG surgery. A 45-year-old male with ESRD under maintenance hemodialysis received CABG surgery for significant coronary artery disease. Two weeks later, he experienced worsening abdominal pain and a palpable mass was noticed in the epigastric region. Computer tomography revealed an unusually large pseudocyst measuring 21 × 17 cm in the retroperitoneum due to necrotizing pancreatitis. The patient underwent percutaneous cystic drainage, and the symptoms were significantly improved without surgical intervention. Factors such as prolonged cardiopulmonary bypass time, postoperative hypotension, and intradialytic hypotension appeared to have contributed to the development of severe pancreatitis in this case. This report highlights the rarity of a giant pancreatic pseudocyst in an ESRD patient after CABG surgery and emphasizes the importance of vigilant postoperative care.

Management of Microvascular Bleeding after On-Pump Cardiac Surgery in a Patient with Perioperative Diagnosis of Impairment of Platelet Responses to Adenosine Diphosphate: A Case Report and a Literature Review

BACKGROUND

Impairment of platelet responses to adenosine diphosphate (ADP) is typified by mild to severe bleeding diathesis, easy bruising, excessive mucosal and post-operative bleeding. Patients lack full platelet activation and aggregation in response to ADP. Following research of the literature in Scopus, PubMed/MEDLINE, ScienceDirect, and the Cochrane Library, we report only 18 patients described to date with impaired platelet response to ADP, none of whom in the high bleeding-risk surgical setting or exploring potential therapeutic options. Data regarding population, putative genetic mutations, modes of inheritance, functional defects, and related clinical manifestations were retrieved from case series and case reports.

CASE PRESENTATION

A 40-year-old woman was scheduled for on-pump cardiac surgery. Her past medical history included episodes of spontaneous mucocutaneous hemorrhages of the mild entity since childhood. Multiple electrode aggregometry (MEA, Multiplate® Roche Diagnostics, Rotkreuz, Switzerland) was used to evaluate platelet response to thrombin-activated peptide-6 (TRAP), arachidonic acid (ASPI), and ADP. An inadequate platelet aggregation induced using a high concentration of ADP with normal TRAP and ASPI tests was detected preoperatively. Therefore, intravenous desmopressin (DVVAP) 0.3 μg/kg body weight was administered to manage microvascular bleeding developed after weaning from cardiopulmonary bypass (CPB).

CONCLUSIONS

Proper management of impaired platelet response to ADP requires a systematic assessment. The Multiplate analyzer is a valuable tool to promptly detect the disorder when a high clinical suspect is present and obtain insights during high bleeding-risk surgical procedures. DVVAP can be beneficial as first-line therapy in bleeding patients to improve platelet function.

T4 Lung Carcinoma with Infiltration of the Thoracic Aorta: Indication and Surgical Procedure

Lung carcinomas infiltrate the aorta mostly on the left side and are altogether rare. As an initial step, complete staging is performed and the results are evaluated in an interdisciplinary tumor board. If the patient's general condition including cardiopulmonary reserves is sufficient, and if there is neither distant metastasis nor an N2 situation, surgical resection may be indicated. The option for neoadjuvant chemotherapy should always be taken into consideration. Depending on the anatomic tumor location, partial lung resection and resection of the affected aortic wall are performed employing a cardiopulmonary bypass. The resected aortic wall is replaced by a vascular prosthesis. In recent years, this proven procedure has partly been replaced by an alternative one, avoiding extracorporeal circulation. An endoaortic stent is implanted in the affected area followed by partial lung resection and resection of the diseased aortic wall. This new procedure has significantly reduced perioperative mortality and morbidity. With proper patient selection, long-term survival can be improved even in this complex malignoma.

2021 MiECTiS focused update on the 2016 position paper for the use of minimal invasive extracorporeal circulation in cardiac surgery

The landmark 2016 Minimal Invasive Extracorporeal Technologies International Society (MiECTiS) position paper promoted the creation of a common language between cardiac surgeons, anesthesiologists and perfusionists which led to the development of a stable framework that paved the way for the advancement of minimal invasive perfusion and related technologies. The current expert consensus document offers an update in areas for which new evidence has emerged. In the light of published literature, modular minimal invasive extracorporeal circulation (MiECC) has been established as a safe and effective perfusion technique that increases biocompatibility and ultimately ensures perfusion safety in all adult cardiac surgical procedures, including re-operations, aortic arch and emergency surgery. Moreover, it was recognized that incorporation of MiECC strategies advances minimal invasive cardiac surgery (MICS) by combining reduced surgical trauma with minimal physiologic derangements. Minimal Invasive Extracorporeal Technologies International Society considers MiECC as a physiologically-based multidisciplinary strategy for performing cardiac surgery that is associated with significant evidence-based clinical benefit that has accrued over the years. Widespread adoption of this technology is thus strongly advocated to obtain additional healthcare benefit while advancing patient care.

Risk of prolonged ischemic time linked to use of cardiopulmonary bypass during implantation for lung transplantation in the United Kingdom

BACKGROUND

Some degree of ischemia is inevitable in organ transplantation, and for most, if not all organs, there is a relationship between ischemic time and transplant outcome. The contribution of ischemic time to lung injury is unclear, with conflicting recent data. In this study, we investigate the impact of ischemia time on survival after lung transplantation in a large national cohort.

METHODS

We studied the outcomes for 1,565 UK adult lung transplants over a 12-year period, for whom donor, transplant, and recipient data were available from the UK Transplant Registry. We examined the effect of ischemia time (defined as donor cross-clamp to recipient reperfusion) and whether standard cardiopulmonary bypass was used using Cox proportional hazards models, adjusting for other risk factors.

RESULTS

The total ischemic time increased from a median under 5 hours in 2003 to over 6.2 hours in 2013. Our findings show that, when the cardiopulmonary bypass was used, there was an increase in the hazard of death (of 13% [95% CI: 5%-21%] for 1-year patient survival) for each hour of total ischemic time. However, if the cardiopulmonary bypass was not used for implantation, this link disappeared-there was no statistically significant change in mortality with increasing ischemic time.

CONCLUSIONS

We document that avoidance of bypass may remove ischemic time, within the limits of our observed range of ischemic times, as a risk factor for poor outcomes. Our data add to the evidence that bypass may be harmful to the donor lung.