Duration Of Deep Hypothermic Circulatory Arrest Research Articles

Effect of the Duration of Deep Hypothermic Circulatory Arrest on the Neurodevelopmental Outcomes in Children Undergoing Cardiac Surgery

Background/Objectives: Deep hypothermic circulatory arrest (DHCA) is safe, but subtle neurodevelopmental deficits may persist far beyond the perioperative period. We aimed to investigate the relationship between DHCA duration and neurodevelopmental outcomes in young children undergoing cardiac surgery with DHCA. Methods: Children aged < 42 months, including neonates who underwent cardiac surgery using DHCA without regional perfusion techniques, were included as the DHCA group. Children in the same age range who underwent cardiac surgery without DHCA were included as the control group. All enrolled patients underwent neurodevelopmental assessment using the Bayley Scales of Infant and Toddler Development (BSTID) by a trained pediatrician, and 17 DHCA patients and 6 control patients completed the BSTID assessment. Results: Both groups showed no significant preoperative, operative, or postoperative differences. Adjusted multivariable analysis revealed that prematurity and age at assessment were significant changing predictors of each of the BSTID components (p < 0.001), except for the gross motor component, where only age at assessment was a significant adjusting predictor. Longer DHCA was associated with lower fine and gross motor BSTID components; however, the association was not statistically significant (p = 0.06). Conclusions: Long-duration DHCA without regional perfusion techniques may be associated with less optimal neurodevelopmental outcomes.

Hyperlactatemia in patients undergoing pulmonary endarterectomy with deep hypothermic circulatory arrest: Risk factors and its effects on the outcome.

To determine the risk factors of hyperlactatemia in pulmonary endarterectomy (PEA) surgery and assess whether elevated blood lactate levels are associated with adverse outcomes. In this retrospective observational study, a total of 111 consecutive patients who underwent PEA for chronic thromboembolic pulmonary hypertension at the XXX Hospital between December 2016 and January 2022 were included. We retrospectively evaluated arterial blood samples analyzed intraoperatively. The pre- and intraoperative risk factors for hyperlactatemia and the postoperative outcomes were recorded. Lactate levels gradually increased during surgery. The optimal cut-off lactate level for major postoperative complications, calculated using receiver operating characteristic analysis, was 7.0mmol/L. Deep hypothermic circulatory arrest (DHCA) duration, nadir hematocrit, and preoperative pulmonary vascular resistance were risk factors for lactate levels >7mmol/L. Moreover, the intraoperative peak lactate level during PEA under DHCA was found to be a statistically significant predictor of major complications being associated with longer mechanical ventilation time (r = 0.294; p = .003) and intensive care unit length of stay (r = 0.327; p = .001). Deep hypothermic circulatory arrest duration, nadir hematocrit, and preoperative pulmonary vascular resistance were associated with hyperlactatemia. Increased lactate levels were independent predictors of longer mechanical ventilation time, intensive care unit length of stay, and major complications.

Risk factors of hyperlactatemia during pulmonary endarterectomy under deep hypothermic circulatory arrest and its influence on prognosis

Objective: To investigate the incidence, risk factors, and outcomes of hyperlactatemia after pulmonary endarterectomy (PEA) under deep hypothermic circulatory arrest (DHCA). Methods: From December 2016 to January 2022, patients receiving PEA in China-Japan Friendship Hospital were enrolled in the study. Arterial blood samples were analyzed intraoperatively. Multivariate logistic regression analysis was performed to identify the predictors of intraoperative lactate elevation as well as major factors influencing the clinical outcome of the surgery. Results: A total of 110 patients (69 males and 41 females) were enrolled, aged (50.6±12.8) years. Receiver operating characteristic curve yielded an optimal cut-off lactate level of 7 mmol/L for predicting major postoperative complications (re-operation, re-intubation, postoperative renal failure requiring renal replacement therapy, wound infection, stroke, atrial fibrillation, and perioperative extracorporeal membrane oxygenation usage within 48 hours after surgery). Thirty-nine patients (35.5%) had an intraoperative peak arterial lactate level of≥7 mmol/L. According to intraoperative peak arterial lactate level, the patients were divided into two groups (<7 mmol/L and≥7 mmol/L). There were no statistically significant differences in age, sex and body mass index between the two groups (all P>0.05). Intraoperative peak lactate level was associated with prolonged mechanical ventilation time (r=0.262, P=0.008) and intensive care unit length of stay (r=0.304, P=0.002). Multivariate logistic regression analysis identified three key variables associated with lactate level≥7 mmol/L: DHCA duration (OR=1.186, 95%CI: 1.027-1.370, P=0.020), nadir hematocrit (HCT) (OR=0.580, 95%CI: 0.341-0.988, P=0.045) and preoperative pulmonary vascular resistance (PVR) (OR=1.096, 95%CI: 1.020-1.177, P=0.012). Patients with lactate≥7 mmol/L carried a higher rate of major complications (P=0.001). For patients with lactate≥7 mmol/L, 41.0% (16 out of 39 cases) had major complications, while for patients with lactate<7 mmol/L, only 14.1% (10 out of 71) had major complications. There was no statistically significant difference in mortality (8.5% vs 10.3%, P=0.753) between patients with different lactate levels. Moreover, intraoperative peak lactate level was a predictor of postoperative combined morbidity (OR=1.625, 95%CI: 1.176-2.245, P=0.003). Conclusion: High intraoperative lactate levels are associated with higher preoperative PVR, lower nadir HCT, and longer DHCA duration. Intraoperative lactate levels are independently associated with increased combined morbidity.

Duration of deep hypothermic circulatory arrest for aortic arch surgery: is it a myth, fiction, or scientific leap?

The use of deep hypothermic circulatory arrest (DHCA) to provide aortic surgeons with a bloodless operative field while simultaneously protecting the brain and peripheries from ischemic damage revolutionized cardiac and aortic surgery, and is currently used in specialist centers across the globe. However, it is associated with manifold adverse outcomes, including neurocognitive dysfunction and mortality. This review seeks to analyze the relationship between DHCA duration and clinical outcome, and evaluate the controversies and limitations surrounding its use. We performed a review of available literature with statistical analysis to evaluate the relationship between DHCA duration (<40 min and >40 min) and key clinical outcomes, including mortality, permanent and temporary neurological deficit, renal damage, admission length, and reintervention rate. The controversies surrounding DHCA use and future directions for care are also explored. Statistical analysis revealed no significant association (P>0.05) between DHCA duration and clinical outcomes (early and late mortality rates, neurological deficit, admission length, and reintervention rate), both with and without adjunctive perfusion techniques. Available literature suggests that the relationships between DHCA duration (with and without adjunctive perfusion) and clinical outcomes are unclear, and at present not statistically significant. Alternative surgical and endovascular techniques have been identified as promising novel approaches not requiring DHCA, as have the use of biomarkers to enable early diagnosis and intervention for aortic pathologies.

Association between Duration of Deep Hypothermic Circulatory Arrest and Surgical Outcome in Patients with Acute Type A Aortic Dissection: A Large Retrospective Cohort Study

(1) Background: Deep hypothermic circulatory arrest (DHCA) with selective antegrade cerebral perfusion (ACP) is an established cerebral protection technique for the conduction of complex surgical procedures involving the aortic arch. It is controversial whether the duration of DHCA is associated with adverse outcome in patients with acute type A aortic dissection (AAAD). Our goal was to investigate whether DHCA time was associated with surgical outcome in patients undergoing a surgical treatment of AAAD. (2) Methods: A total of 410 patients were divided into two groups based on the DHCA time less than 60 min and equal to or longer than 60 min. (3) Results: Patients with longer DHCA times were significantly younger (p = 0.001). Intraoperatively, complex procedures with aortic arch surgery were more common in patients with longer DHCA times (p < 0.001). Accordingly, cardiopulmonary bypass (p < 0.001), cross-clamping (p < 0.001) and DHCA times (p < 0.001) were significantly longer in this group. Postoperatively, only the duration of mechanical ventilation (p < 0.001) and the rate of tracheotomy were significantly higher in these patients. Thirty-day mortality was satisfactory for both groups (p = 0.746). (4) Conclusions: Our results showed that improvements in perioperative management including ACP allow for the successful performance of surgical treatment of AAAD under DHCA with a duration of even longer than 60 min.

Deep Hypothermic Circulatory Arrest in the Pediatric Population Undergoing Cardiac Surgery With Electroencephalography Monitoring: A Systematic Review and Meta-Analysis

Cardiac surgery for repair of congenital heart defects poses unique hazards to the developing brain. Deep hypothermic circulatory arrest (DHCA) is a simple and effective method for facilitating a bloodless surgical field during congenital heart defect repair. There are, however, some concerns that prolonged DHCA increases the risk of nervous system injury. The electroencephalogram (EEG) is used in adult and, to a lesser extent, pediatric cardiac procedures as a neuromonitoring method. The present study was performed to assess outcomes following DHCA with EEG monitoring in the pediatric population. In this systematic review and meta-analysis, the PubMed, Cochrane Central Register of Controlled Trials, Scopus, Institute of Science Index, and Embase databases were searched from inception for relevant articles. A fixed- or random-effects model, as appropriate, was used. Surgical setting. Pediatric population (≤18 y old). DHCA (18°C) with EEG monitoring. Nineteen articles with 1,267 pediatric patients ≤18 years were included. The event rate of clinical and EEG seizures among patients who underwent DHCA was 12.9% and 14.9%, respectively. Mortality was found to have a 6.3% prevalence. A longer duration of DHCA was associated with a higher risk of EEG seizure and neurologic abnormalities. In addition, seizures were associated with increased neurologic abnormalities and neurodevelopmental delay. EEG and neurologic abnormalities were common after DHCA. A longer duration of DHCA was found to lead to more EEG seizure and neurologic abnormalities. Moreover, EEG seizures were more common than clinical seizures. Seizures were found to be associated with increased neurologic abnormalities and neurodevelopmental delay.

Development and Validation of a Seizure Prediction Model in Neonates After Cardiac Surgery

Electroencephalographic seizures (ESs) after neonatal cardiac surgery are often subclinical and have been associated with poor outcomes. An accurate ES prediction model could allow targeted continuous electroencephalographic monitoring (CEEG) for high-risk neonates. ES prediction models were developed and validated in a multicenter prospective cohort where all postoperative neonates who underwent cardiopulmonary bypass (CPB) also underwent CEEG. ESs occurred in 7.4% of neonates (78 of 1053). Model predictors included gestational age, head circumference, single-ventricle defect, deep hypothermic circulatory arrest duration, cardiac arrest, nitric oxide, extracorporeal membrane oxygenation, and delayed sternal closure. The model performed well in the derivation cohort (c-statistic, 0.77; Hosmer-Lemeshow, P= .56), with a net benefit (NB) over monitoring all and none over a threshold probability of 2% in decision curve analysis (DCA). The model had good calibration in the validation cohort (Hosmer-Lemeshow, P= .60); however, discrimination was poor (c-statistic, 0.61), and in DCA there was no NB of the prediction model between the threshold probabilities of 8% and 18%. By using a cut point that emphasized negative predictive value in the derivation cohort, 32% (236 of 737) of neonates would not undergo CEEG, including 3.5% (2 of 58) of neonates with ESs (negative predictive value, 99%; sensitivity, 97%). In this large prospective cohort, a prediction model of ESs in neonates after CPB had good performance in the derivation cohort, with an NB in DCA. However, performance in the validation cohort was weak, with poor discrimination, poor calibration, and no NB in DCA. These findings support CEEG of all neonates after CPB.

Preoperative platelet count, preoperative hemoglobin concentration and deep hypothermic circulatory arrest duration are risk factors for acute kidney injury after pulmonary endarterectomy: a retrospective cohort study

BackgroundAcute kidney injury (AKI) is a major postoperative morbidity of patients undergoing cardiac surgery and has a negative effect on prognosis. The kidney outcomes after pulmonary endarterectomy (PEA) have not yet been reported; However, several perioperative characteristics of PEA may induce postoperative AKI. The objective of our study was to identify the incidence and risk factors for postoperative AKI and its association with short-term outcomes.MethodsThis was a single-center, retrospective, observational, cohort study. Assessments of AKI diagnosis was executed based on the Kidney Disease Improving Global Outcomes (KDIGO) criteria.ResultsA total of 123 consecutive patients who underwent PEA between 2014 and 2018 were included.The incidence of postoperative AKI was 45% in the study population. Stage 3 AKI was associated with worse short-term outcomes and 90-day mortality (p < 0.001, p = 0.002, respectively). The independent predictors of postoperative AKI were the preoperative platelet count (OR 0.992; 95%CI 0.984–0.999; P = 0.022), preoperative hemoglobin concentration (OR 0.969; 95%CI 0.946–0.993; P = 0.01) and deep hypothermic circulatory arrest (DHCA) time (OR 1.197; 95%CI 1.052–1.362; P = 0.006) in the multivariate analysis.ConclusionThe incidence of postoperative AKI was relatively high after PEA compared with other types of cardiothoracic surgeries. The preoperative platelet count, preoperative hemoglobin concentration and DHCA duration were modifiable predictors of AKI, and patients may benefit from some low-risk, low-cost perioperative measures.

Hypothermic circulatory arrest with or without antegrade cerebral perfusion for aortic arch surgery in infants

Background: Antegrade cerebral perfusion (ACP) minimizes deep hypothermic circulatory arrest (DHCA) duration during arch surgery in infants, which may impact the outcomes of the repair. We aimed to evaluate the effect of adding antegrade cerebral perfusion to deep hypothermic circulatory arrest on DHCA duration and operative outcomes of different aortic arch operations in infants.&#x0D; Methods: We retrospectively collected data from infants (&lt;20 weeks old) who underwent aortic arch reconstruction (Norwood operation, arch reconstruction for the hypoplastic arch and interrupted aortic arch) using DHCA alone (n=88) or combined with ACP (n=26). We excluded patients who had concomitant procedures and those with preoperative neurological disability.&#x0D; Results: There was no difference between groups as regards the age, gender, and the operation performed (p= 0.64; 0.87 and 0.50; respectively). Among the 114 patients, 11 (9.6%) had operative mortality, and 14 (12.3%) had cerebral infarction diagnosed with CT scanning. Adding ACP to DHCA significantly reduced DHCA duration from 50.7 ± 10.6 minutes to 22.4 ± 6.2 minutes (p&lt;0.001) and lowered the mortality (11 vs. 0; p=0.066) and cerebral infarction (13 vs. 1; p=0.18). No statistically significant difference between the two groups in terms of ischemic time (p=0.63) or hospital stay duration (p=0.47).&#x0D; Conclusion: Using ACP appears to reduce the DHCA duration and was associated with better survival and neurological outcomes of aortic arch surgery in infants. A study with longer follow-up to evaluate the long-term neurological sequelae is recommended.

Retrograde Cerebral Perfusion Is Effective for Prolonged Circulatory Arrest in Arch Aneurysm Repair

The optimal brain protection strategy for prolonged periods of circulatory arrest is still controversial. This study evaluated whether retrograde cerebral perfusion (RCP) provides adequate brain protection for prolonged periods of deep hypothermic circulatory arrest (DHCA). From January 1997 to December 2014, 1,043 patients underwent aortic arch operations using RCP and DHCA at 18°C. The DHCA time for 993 patients was 49 minutes or less and the DHCA time for the remaining 50 patients was 50 minutes or more. Propensity matching between the two groups was performed, taking into account the main preoperative and surgical variables and all the preoperative and intraoperative neurologic risk factors. Logistic regression analysis was performed to identify independent predictors of operative death and postoperative cerebral complications. In the unmatched population, mortality in the 50 minutes or more vs the 49 minutes or less group was 8% vs 3.8% (p= 0.143), and the stroke rate was 2% vs 1.2% (p= 0.623). Propensity matching resulted in 48 pairs. Operative death and incidence of transient and permanent neurologic deficit were similar and not statistically significant in the matched groups for all comparisons. No difference in the incidence of other major postoperative complications was found between the two groups. Midterm survival was similar. Regression analysis showed DHCA duration was not independently associated with operative death or postoperative neurologic deficits. RCP is an effective adjunctive cerebral protection strategy for complex aortic arch aneurysm repair with prolonged DHCA and is not associated with increased death or neurologic complications.

Favorable late survival after aortic surgery under straight deep hypothermic circulatory arrest

BackgroundSurgical and cerebral protection strategies in aortic arch surgery remain under debate. Perioperative results using deep hypothermic circulatory arrest (DHCA) have been associated with favorable short-term mortality and stroke rates. The present study focuses on late survival in patients undergoing aortic surgery using DHCA. MethodsA total of 613 patients (mean age, 63.7 years) underwent aortic surgery between January 2003 and December 2015 using DHCA, with 77.3% undergoing hemiarch replacement and 20.4% undergoing arch replacement, with a mean DHCA duration of 29.7 ± 8.5 minutes (range, 10-62 minutes). We examined follow-up extending up to a mean of 3.8 ± 3.4 years (range, 0-14.1 years). ResultsOperative mortality was 2.9%, and the stroke rate was 2%. Survival was 92.2% at 1 year and 81.5% at 5 years, significantly lower than the values in an age- and sex-matched reference population. In elective, nondissection first-time surgeries (n = 424), survival was similar to that of the reference group. Acute type A aortic dissection (hazard ratio [HR], 4.84; P = .000), redo (HR, 4.12; P = .000), and descending aortic pathology (HR, 5.54: P = .000) were independently associated with reduced 1-year survival. Beyond 1 year, age (HR, 1.07; P = .000), major complications (HR, 3.11; P = .000), and atrial fibrillation (HR, 2.47; P = .006) were independently associated with poor survival. DHCA time was not significantly associated with survival in multivariable analysis. ConclusionsAortic surgery with DHCA can be performed with favorable late survival, with the duration of DHCA period having only a limited impact. However, these results cannot be generalized for very long durations of DHCA (>50 minutes), when perfusion methods may be preferable. In elective, nondissection first-time surgeries, a late survival comparable to that in a reference population can be achieved. Early survival is adversely affected by aortic dissection, redo status, and disease extent.

The neurologic protection of unilateral versus bilateral antegrade cerebral perfusion in aortic arch surgery with deep hypothermic circulatory arrest: A study of 77 cases

BackgroudUnilateral and bilateral antegrade cerebral perfusions (ACP) are recognized methods of cerebral protection in aortic arch surgery. However, the adequacy of cerebral protection in aortic arch surgery with deep hypothermic circulatory arrest is controversial. In this study, we compared unilateral and bilateral ACP of cerebral protection in aortic arch surgery by assessing the patient's intraoperative and postoperative brain function. MethodsA total of 77 patients undergoing aortic arch surgery were included in this study. Unilateral ACP was performed using a cannula in the innominate artery (n = 40), whereas bilateral ACP was conducted using an additional cannula in the left carotid artery (n = 37). Levels of S-100β and neuron specific enolase (NSE) were assayed at the beginning of cardiopulmonary bypass (T1), the beginning of circulatory arrest (T2), and post ACP at T = 25 min (T3), the end of ACP (T4), the end of cardiopulmonary bypass (T5), and at T = 1 h (T6), T = 6 h (T7), and T = 24 h (T8). Transcranial Doppler ultrasonography was used both preoperatively and intraoperatively to detect the blood flow of bilateral middle cerebral artery (MCA), and neurologic deficit incidence and mortality rates were obtained. ResultsAt time points T1, T2, and T3, plasma levels of S-100β and NSE were not statistically different between groups. However, S-100β and NSE levels for each time point ranging from T = T4 to T = T8 did show statistically significant differences between groups. Patients who with one side of the middle cerebral artery stenosis, used bilateral antegrade cerebral perfusions method, intraoperative Transcranial Doppler ultrasonography examination showed narrow side blood flow weaker than the normal side during the deep hypothermic circulatory arrest (DHCA), however no significant differences could be observed between the two sides (P > 0.05). The incidence of neurological dysfunction was higher in the unilateral ACP group compared to the bilateral ACP group (25% vs. 8.11%, respectively, P = 0.028). Moreover, no marked differences were observed in mortality (2.5% vs. 5.41%, respectively, P = 1.000). ConclusionsWhen the duration of DHCA was 25 min or less, no significant differences were observed between unilateral and bilateral ACP. However, when DHCA exceeded 25 min, bilateral ACP was more effective compared to unilateral ACP. Due to the high variations in circle of Willis as well as increased safety, simplicity, and efficiency, the bilateral ACP approach is preferred over the unilateral technique.

Analysis of risk factors for and the prognosis of postoperative acute respiratory distress syndrome in patients with Stanford type A aortic dissection.

To explore the risk factors for and the prognosis of postoperative acute respiratory distress syndrome (ARDS) in patients with Stanford type A aortic dissection (AD). This retrospective nested case-control study included 527 Stanford type A AD patients who were divided into ARDS groups and non-ARDS groups. The clinical features of the groups were examined. The fifty-nine patients in the ARDS group exhibited extended durations of cardiopulmonary bypass (CPB) (P=0.004), deep hypothermic circulatory arrest (DHCA) (P=0.000), ventilator support (P=0.013) and intensive care unit (ICU) stay (P=0.045), higher hospital costs (P=0.000), larger perioperative transfusions volumes [red blood cells (RBC): P=0.002, platelets (PLT): P=0.040, fresh frozen plasma (FFP): P=0.001], more frequent pulmonary infection (P=0.018) and multiple organ dysfunction syndrome (MODS) (P=0.040) and a higher rate of in-hospital mortality (P=0.020). The ARDS group exhibited worse statuses in terms of oxygenation index (OI) values (P=0.000) and Apache II scores (P=0.000). DHCA [P=0.000, odds ratio (OR) =2.589] and perioperative transfusion (RBC: P=0.000, OR =2.573; PLT: P=0.027, OR =1.571; FFP: P=0.002, OR =1.929) were independent risk factors for postoperative ARDS. The survival rates and median survival times after discharge were similar between the two groups (P=0.843). DHCA duration and perioperative transfusion volume were independent risk factors for postoperative ARDS which warrants greater attention by the cardiac surgeons.

Variation in Perfusion Strategies for Neonatal and Infant Aortic Arch Repair: Contemporary Practice in the STS Congenital Heart Surgery Database.

Regional cerebral perfusion (RCP) is used as an adjunct or alternative to deep hypothermic circulatory arrest (DHCA) for neonates and infants undergoing aortic arch repair. Clinical studies have not demonstrated clear superiority of either strategy, and multicenter data regarding current use of these strategies are lacking. We sought to describe the variability in contemporary practice patterns for use of these techniques. The Society of Thoracic Surgeons Congenital Heart Surgery Database (2010-2013) was queried to identify neonates and infants whose index operation involved aortic arch repair with cardiopulmonary bypass. Perfusion strategy was classified as isolated DHCA, RCP (with less than or equal to ten minutes of DHCA), or mixed (RCP with more than ten minutes of DHCA). Data were analyzed for the entire cohort and stratified by operation subgroups. Overall, 4,523 patients (105 centers) were identified; median age seven days (interquartile range: 5.0-13.0). The most prevalent perfusion strategy was RCP (43%). Deep hypothermic circulatory arrest and mixed perfusion accounted for 32% and 16% of cases, respectively. In all, 59% of operations involved some period of RCP. Regional cerebral perfusion was the most prevalent perfusion strategy for each operation subgroup. Neither age nor weight was associated with perfusion strategy, but reoperations were less likely to use RCP (31% vs 45%, P < .001). The combined duration of RCP and DHCA in the RCP group was longer than the DHCA time in the DHCA group (45 vs 36 minutes, P < .001). There is considerable variability in practice regarding perfusion strategies for arch repair in neonates and infants. In contemporary practice, RCP is the most prevalent perfusion strategy for these procedures. Use of DHCA is also common. Further investigation is warranted to ascertain possible relative merits of the various perfusion techniques.

Severity and Duration of Metabolic Acidosis After Deep Hypothermic Circulatory Arrest for Thoracic Aortic Surgery.

To determine the severity, duration, and contributing factors for metabolic acidosis after deep hypothermic circulatory arrest (DHCA). Retrospective observational study. University hospital. Eighty-seven consecutive patients undergoing elective thoracic aortic surgery with DHCA. Regression analysis was used to test for relationships between the severity of metabolic acidosis and clinical and laboratory variables. Minimum pH averaged 7.27±0.06, with 76 (87%) having a pH<7.35; 55 (63%), a pH<7.30; and 7 (8%), a pH<7.20. The mean duration of metabolic acidosis was 7.9±5.0 hours (range: 0.0 - 26.8), and time to minimum pH after DHCA was 4.3±2.0 hours (1.0 - 10.0 hours). Hyperchloremia contributed to metabolic acidosis in 89% of patients. The severity of metabolic acidosis correlated with maximum lactate (p<0.0001) and hospital length of stay (LOS) (r = 0.22, p<0.05), but not with DHCA time, DHCA temperature, duration of vasoactive infusions, or ICU LOS. Patient BMI was the sole preoperative predictor of the severity of postoperative metabolic acidosis. This retrospective analysis involved short-term clinical outcomes related to pH severity and duration, which indirectly may have included the impact of sodium bicarbonate administration. Metabolic acidosis was common and severe after DHCA and was attributed to both lactic and hyperchloremic acidosis. DHCA duration and temperature had little impact on the severity of metabolic acidosis. The severity of metabolic acidosis was best predicted by the BMI and had minimal effects on short-term outcomes. Preventing hyperchloremic acidosis has the potential to decrease the severity of metabolic acidosis after DHCA.

Subclinical seizures identified by postoperative electroencephalographic monitoring are common after neonatal cardiac surgery

ObjectivesThe American Clinical Neurophysiology Society recommends continuous electroencephalographic monitoring after neonatal cardiac surgery because seizures are common, often subclinical, and associated with worse neurocognitive outcomes. We performed a quality improvement project to monitor for postoperative seizures in neonates with congenital heart disease after surgery with cardiopulmonary bypass. MethodsWe implemented routine continuous electroencephalographic monitoring and reviewed the results for an 18-month period. Clinical data were collected by chart review, and continuous electroencephalographic tracings were interpreted using standardized American Clinical Neurophysiology Society terminology. Electrographic seizures were classified as electroencephalogram-only or electroclinical seizures. Multiple logistic regression was used to assess associations between seizures and potential clinical and electroencephalogram predictors. ResultsA total of 161 of 172 eligible neonates (94%) underwent continuous electroencephalographic monitoring. Electrographic seizures occurred in 13 neonates (8%) beginning at a median of 20 hours after return to the intensive care unit after surgery. Neonates with all types of congenital heart disease had seizures. Seizures were electroencephalogram only in 11 neonates (85%). Status epilepticus occurred in 8 neonates (62%). In separate multivariate models, delayed sternal closure or longer deep hypothermic circulatory arrest duration was associated with an increased risk for seizures. Mortality was higher among neonates with than without seizures (38% vs 3%, P < .001). ConclusionsContinuous electroencephalographic monitoring identified seizures in 8% of neonates after cardiac surgery with cardiopulmonary bypass. The majority of seizures had no clinical correlate and would not have been otherwise identified. Seizure occurrence is a marker of greater illness severity and increased mortality. Further study is needed to determine whether seizure identification and management lead to improved outcomes.

Neuropsychological performance of school-aged children after staged surgical palliation of hypoplastic left heart syndrome.

Despite advances in perioperative management during surgical treatment of hypoplastic left heart syndrome (HLHS), patients are still at risk for adverse neurodevelopmental sequelae including cognitive dysfunction. This study aimed to assess a neuropsychological profile of HLHS patients at school age who underwent the Norwood operation between 1996 and 2003 with deep hypothermic circulatory arrest (DHCA) or antegrade selective cerebral perfusion (ASCP), respectively. Forty HLHS patients (DHCA: n = 11 and ASCP: n = 29) were compared with healthy controls (DHCA controls: n = 10 and ASCP controls: n = 24), recruited according to age, sex and socioeconomic status. Neuropsychological assessment included non-verbal intelligence (IQ norms) and raw score measures of visual and verbal short- and long-term memory as well as executive functions, processing speed and concentration. Neuropsychological data were correlated with bypass and circulatory arrest times. Compared with control subjects, both patient groups had average non-verbal intelligence scores [DHCA: 102 (72-112) and ASCP: 92 (70-127)], but showed reduced long-term memory capacities and decreased executive performance as well as reduced processing speed. DHCA patients, furthermore, had a reduced visual attention span, and ASCP patients scored less on the verbal learning task than controls. The duration of DHCA and cardiopulmonary bypass (CPB) was associated with visual executive functions and short-term memory. In the DHCA group, the duration of DHCA was correlated with the time to complete the Trail Making Test A measuring visual executive functions (Spearman rank correlation, rS = 0.867, P = 0.018). In patients provided with ASCP, the cumulated CPB duration was negatively correlated with the score of the block span test measuring visual short memory (rS = -0.476, P = 0.020) as well as with the copy score of the Rey Figure assessing visual executive functions (rS = -0.399, P = 0.032). School-age children with HLHS who underwent the Norwood procedure either with DHCA or ASCP show cognitive impairments compared with healthy controls. Our data indicate deficits in specific cognitive domains such as memory, executive functions and processing speed rather than basic intellectual dysfunction.

Straight deep hypothermic circulatory arrest for cerebral protection during aortic arch surgery: Safe and effective

To evaluate our extensive clinical experience using deep hypothermic circulatory arrest (DHCA) as a sole method of cerebral protection during aortic arch surgery, with an emphasis on determining the safe duration of DHCA. A total of 490 consecutive patients (303 males [61.8%], mean age, 62.7 ± 13.5 years) underwent surgical interventions on the aortic arch with straight DHCA for cerebral protection. Of the procedures, 65 (13.3%) were either urgent or emergency. Aortic aneurysms (n = 417, 85.1%) and dissections (n = 71, 14.5%) were the main indications for surgery. The mean DHCA duration was 29.2 ± 7.9 minutes at a mean bladder temperature of 18.7°C. The overall mortality was 2.4% (12 of 490), and elective mortality was 1.4% (6 of 425). The seizure rate was 1.4% (7 of 490). Six patients (1.2%) developed renal failure that required dialysis. The postoperative stroke rate was 1.6% (8 of 490) and was 1.2% (5 of 425) for the elective cases. The overall stroke rate for patients requiring <50 minutes of DHCA was 1.3% (6 of 478), significantly different from the 16.7% (2 of 12) stroke rate for patients requiring >50 minutes of DHCA (P = .014). Multivariate analysis revealed a DHCA time >50 minutes (odds ratio, 5.11 ± 4.01, P = .038) and aortic dissection (odds ratio, 3.59 ± 1.72, P = .008) to be strong predictors of composite adverse outcomes. Straight DHCA is a safe and effective technique of cerebral protection for the absolute majority of interventions involving the aortic arch. At experienced centers, up to 50 minutes of DHCA can be considered safe, without significant postoperative mortality or neurologic sequelae.

Neurodevelopmental Outcomes After Infant Cardiac Surgery With Circulatory Arrest and Intermittent Perfusion

Optimal perfusion strategies for neuroprotection during infant cardiac surgery remain undefined. Despite encouraging experimental data, neurodevelopmental (ND) outcomes after cardiac surgery in neonates and infants using deep hypothermic circulatory arrest (DHCA) with a period of intermittent perfusion have not been reported, and it is not known whether DHCA can be extended while preserving ND outcomes. Cross-sectional ND evaluation with the Bayley Scales of Infant and Toddler Development, Third Edition was conducted at 24 months of age. Retrospective clinical data were extracted from the electronic medical record. Forty patients underwent cardiac surgery during the first year of life using a period of uninterrupted DHCA (24 patients) or DHCA interrupted by a period of intermittent perfusion (16 patients). Total duration of DHCA ranged from 5 to 74 minutes and did not predict ND scores. Despite a longer exposure to DHCA in the intermittent perfusion group (55 minutes [1,3 interquartile [IQ] 45.3 to 65.5] versus 38 minutes [1,3 IQ 32 to 40.8]), no differences in ND scores were detected. Significant comorbidities, duration of intensive care unit and hospital stay, as well as multiple procedures with DHCA were independent predictors of ND outcomes at 24 months of age. Despite extended duration of total DHCA, the use of a period of intermittent perfusion to limit uninterrupted DHCA periods to less than 45 minutes could lead to ND outcomes similar to those of patients exposed to brief periods of DHCA. Deep hypothermic circulatory arrest with intermittent perfusion may facilitate implementation of prospective studies to identify the optimal cerebral perfusion strategy.

Post-operative acute kidney injury in Stanford Type A aortic dissection

Results Mean age was 52 ± 12 years. In-hospital peri-operative mortality was 12.9%. Mean aortic cross-clamp time was 124 ± 72 minutes; mean duration of deep hypothermic circulatory arrest (DHCA) was 47 ± 30 minutes. 25.8% of patients developed post-operative acute kidney injury. 6.5% required temporary renal replacement therapy. Preoperative renal impairment and presence of ischemic heart disease were significant predictors of the need for post-operative hemodialysis. Pre-operative serum creatinine level was a statistical significant risk factor of elevated serum creatinine on the 1st, 2nd and 3rd postoperative day. Duration of DHCA, cardiopulmonary bypass time and body surface area were significant predictors of elevated serum creatinine on the 1st postoperative day. Aortic cross-clamp time correlated significantly wit duration of hemodialysis (p=0.041). Presence of pre-operative renal impairment correlated significantly with the need for hemodialysis (p=0.035). Intra-operative urine output did not correlate significantly with postoperative serum creatinine (p=0.055) or the duration of hemodialysis (p=0.392).