Effects of pulmonary perfusion during cardiopulmonary bypass on lung functions after cardiac operation.

BACKGROUND: Pulmonary artery perfusion during cardiopulmonary bypass (CPB) is a known but rarely used technique in adult cardiac surgery. In this study, we aimed to investigate biochemical and histopathological effects of pulmonary artery perfusion during CPB on lung functions. METHODS: Between May 2014 and August 2014, all patients (n = 24) who gave informed consent for participating this study with inclusion criteria were included. Patients undergoing isolated coronary artery bypass grafting were sequentially randomized to conventional CPB (control group, n = 12) and conventional CPB with selective pulmonary artery perfusion (study group, n = 12). Lung functions were monitored using PF ratio, alveolar-arterial oxygen gradient, and lactate levels. A small sample tissue from the left lung was excised for histopathologic examination. Immunocytochemistry analysis was performed using anti-rabbit polyclonal vascular endothelial growth factor (VEGF), rabbit polyclonal inducible nitric oxide synthase (i-NOS), and BCL-2 antibodies. RESULTS: Postoperative course of the patients were uneventful without any clinical outcome differences in terms of cardiopulmonary complications, ventilation time and hospital stay. Pulmonary perfusion group had significantly better oxygenation values after extubation and at postoperative 24-hour. Electron microscopy examinations revealed better preservation of the alveolar wall integrity with pulmonary perfusion. The intensity of VEGF, i-NOS, and BCL-2 antibody expressions in bronchial epithelial cells were more prominent in the pulmonary perfusion group. CONCLUSIONS: Pulmonary artery perfusion during aortic cross-clamping provides better oxygenation and preservation of the wall alveolar integrity after coronary artery bypass grafting surgery. This technique can be used as a protective strategy to minimize CPB-induced lung injury in adult cardiac surgery.

Evaluation of the possible involvement of Ad-36-induced adipogenesis and coronary artery disease development in mediastinal adipose tissue samples.

Mediastinal fat has been suggested to be associated with cardiovascular diseases such as carotid stiffness, atherosclerosis and coronary artery calcification. We investigated the possible role of Ad-36-induced obesity in the pathogenesis of the coronary artery disease (CAD). Ad-36 DNA was investigated in the anterior mediastinal fat tissue samples of obese adults with CAD. Seventy-five obese adults with left main coronary artery (LMCA) disease, 28 non-obese adults with valvular heart diseases, and 48 healthy individuals without cardiovascular problems were included as the obese patient group (OPG), non-obese patient group (NOG) and healthy control group (HCG), respectively. We also simultaneously investigated Ad-36 antibodies by serum neutralization test (SNA), and measured leptin and adinopectin levels. Ad-36 antibodies were detected only in 10 patients (13.3%) within the 75 OPG. A statistically significant difference was detected between OPG, NOG and HCG in terms of Ad-36 antibody positivity (p>0.05). Ad-36 DNA was not detected in mediastinal tissue samples of OPG and NOP without PCR inhibitors. We suggest that Ad-36 may not have an affinity for mediastinal adipose tissue in obese patients with left main CAD and valvular heart diseases. Ad-36 antibody positivity results are not sufficient to reach a causal relationship.

The use of neonatal extracorporeal life support in pediatric cardiac intensive care unit.

AIM: The aim of the study is to evaluate extracorporeal life support system (ECLS) employed in neonates in pediatric cardiac intensive care unit. MATERIAL AND METHODS: Twenty-five neonates that required ECLS in between November 2010 and November 2015 were evaluated. RESULTS: The median age was 12 days (range 3-28 days) and the median body weight was 3 kg (range 2.5-5 kg). Venoarterial ECLS was performed in all of the cases. Ascendan aorta-right atrial cannulation in 22 patients and neck cannulation in three patients were performed. The reason for ECLS was E-CPR in two patients, inability to wean from cardiopulmonary bypass (CPB) in seven patients, respiratory insufficiency and hypoxia in nine patients, low cardiac output (LCOS) in seven patients. Median duration of ECLS was four days (range 1-15). Hemorrhagic complications developed in 15, renal complications in 13, pulmonary complications in 12, infectious complications in 11, neurologic complications in three and mechanical complications in two of the patients. Weaning was successful in 15 of the patients. Eleven patients were successfully discharged. CONCLUSION: ECLS is an important treatment option that is performed successfully in many centers around the world to maintain life support in patients unresponsive to medical treatment. The utilization of this modality especially in newborns with congenital heart disease should be taken into consideration.

Staged or Combined Approach for Carotid Endarterectomy in Patients Undergoing Coronary Artery Bypass Grafting: A 5-Year-Long Experience.

BACKGROUND: Optimal surgical approach for patients with hemodynamically significant carotid and coronary disease remains controversial. We analyzed our 5-year experience and compared early and long-term outcome following staged and combined carotid and coronary artery bypass. METHODS: 312 consecutive patients undergoing carotid endarterectomy and coronary artery bypass between 2008 and 2013 were prospectively enrolled in the study. Patients were scheduled for a staged (carotid endarterectomy followed by coronary artery bypass within 1 week) procedure (Group S) unless they were unstable in terms of cardiac status (were deemed to a combined procedure; Group C). All patient data including demographics, risk factors, immediate perioperative events, 30-day, and long-term outcome were prospectively recorded and then analyzed. Groups S and C were compared for pre- and perioperative data as well as immediate, 30-day, and long-term survival. A P value less than .05 was considered significant. Survival analysis was made using Kaplan-Meier method and log-rank test. RESULTS: Group S included 204 patients and Group C included 108 patients. Preoperative demographics and clinical data were similar in the two groups except that preoperative cerebrovascular events were more common in Group C (31.7% versus 22.22%, P = .036) and bilateral carotid disease was more common in Group S. The EuroSCORE was higher in Group C (2.91 versus 2.65, P = .013). Carotid surgery techniques were similar; intraluminal shunting was more frequent in group C than group S (33.33% versus 9.88%, P = .001). Additional cardiac procedures in addition to coronary surgery was predominant in Group C. 30-day neurological adverse event rates, ICU, and hospital stay were significantly higher in Group C. The 30-day mortality was also sigficantly higher in Group C (1.96% versus 4.62%, P = .001). CONCLUSION: Staged and combined surgical approaches yield comparable outcomes. A staged approach may provide a more favorable neurological outcome with significantly reduced need for intraluminal shunting. Long-term outcome is, however, similar.

Impact of Coronary Artery Anatomy in Arterial Switch Procedure on Early Mortality and Morbidity.

OBJECTIVE: Arterial switch operation has become the treatment of choice for neonates with transposition of the great arteries. The most important step of the procedure is transferring the coronary arteries to the neoaorta successfully. This study shows the impact of coronary anatomy on early mortality and morbidity after arterial switch operation. METHODS: Ninety-two patients with transposition of the great arteries who underwent arterial switch operation between October 2010 and September 2014 were included in this retrospective study. The patients were classified into two groups: group I (n = 68, patients with usual coronary artery anatomy) and group II (n = 24, patients with unusual coronary artery anatomy). Median age was 10 days (6-25 days) in group I and 14 days (7-29 days) in group II. In group I, 25 patients had ventricular septal defect, nine patients had coarctation of the aorta or distal aortic arch hypoplasia, seven patients had Taussig Bing anomaly. In group II, nine patients had ventricular septal defect, one patient had coarctation of aorta, and one patient had Taussig Bing anomaly. RESULTS: Regarding the postoperative variables, no significant statistical difference was found between two groups. But cardiopulmonary bypass time is significantly longer in group II (P = .004). There was no difference in complications including the mortality (P = .265). It is statistically found that associated anomalies did not affect the mortality and complication rates. All mortality cases (n = 4) were related to ventricular dysfunction in group II, whereas only four of the eight patients died because of ventricular dysfunction in group I. CONCLUSION: Coronary artery pattern was not a predictor of mortality in early postoperative period. There may be an impact of unusual coronary artery pattern on the development of ventricular dysfunction as a cause of mortality.

Fondaparinux Treatment in a Neonate with Heparin Induced Thrombocytopenia during Extracorporeal Life Support.

The utilization of mechanical life support due to respiratory insufficiency and serious cardiac pathologies have been increasing. Anticoagulation to prevent clot formation is mandatory and unfractioned heparin is the standard therapy in use. But rarely heparin induced thrombocytopenia (HIT) might develop as an immunologic side effect of heparin. Development of thrombosis as a result of HIT increases the morbidity and mortality. We present a neonate with HIT treated successfully with fondaparinux under extracorporeal life support.

Effect of vitamin D deficiency on the development of postoperative atrial fibrillation in coronary artery bypass patients.

Introduction: Various factors may be responsible for the development of postoperative atrial fibrillation (POAF) in coronary artery bypass graft (CABG) patients. In our study, we demonstrated the effect of vitamin D deficiency on the development of POAF. Methods: In this prospective case control study, patients undergoing elective, isolated CABG were considered. A total of 15 patients (16.6%) who developed POAF during the first five days after surgery made up the POAF group. Seventy-five patients that had a sinus rhythm in the same period were the non-POAF group. The two groups were compared statistically in terms of laboratory, clinical, echocardiographic, operative, and postoperative parameters. Results: All patients were in sinus rhythm at discharge. The baseline characteristics of the study groups were comparable. The POAF group had a lower vitamin D level than the non-POAF group (9.0 ± 5.0 and 15.0 ± 8.4 ng/mL, respectively; P=0.007). In the POAF group, the patients' left atrium diameter and incidence of hypertension (HT) were higher than those of the non-POAF group. Conclusion: Incidence of POAF was significantly higher in patients with vitamin D deficiency or insufficiency than the patients with vitamin D level in normal range. Therefore vitamin D deficiency or insufficiency may be a predictor of POAF in patients with CABG.

Mitral valve regurgitation due to annular dilatation caused by a huge and floating left atrial myxoma.

We describe a case of mitral valve annular dilatation caused by a huge left atrial myxoma obstructing the mitral valve orifice. A 50-year-old man presenting with palpitation was found to have a huge left atrial myxoma protruding into the left ventricle during diastole, causing severe mitral regurgitation. The diagnosis was made with echocardiogram. Transoesophageal echocardiography revealed a solid mass of 75 × 55 mm. During operation, the myxoma was completely removed from its attachment in the atrium. We preferred to place a mechanical heart valve after an annuloplasty ring because of severely dilated mitral annulus and chordae elongation. The patient had an uneventful recovery. Our case suggests that immediate surgery, careful evaluation of mitral valve annulus preoperatively is recommended.

Effect of Proximal Anastomotic Diameter on Venous Bypass Graft Patency in Patients Undergoing Coronary Artery Bypass Grafting.

BACKGROUND: In this study, the relationship between patency of saphenous vein (SV) graft and different sizes of aorta wall punches was investigated during the follow-up period after coronary artery bypass graft surgery. We also evaluated the other possible factors affecting SV graft patency. METHODS: This study consisted of 266 consecutive and symptomatic patients with postoperative angiography. The primary endpoint was at least one saphenous graft failure observed from coronary computed tomography angiography (cCTA) and/or invasive angiography after surgery. Groups were created as SV occluded and patent group. Survival curves of patients in groups were estimated using Kaplan-Meier method and compared by log-rank test. Multivariate analysis was performed using the Cox proportional hazard model. RESULTS: Cox-regression analysis demonstrated influence of older age (P = .023) and Diabetes Mellitus (DM) (P = .002) on SV graft failure. However, increasing ejection fraction (P = .011) was a protective factor against SV graft failure. There was no significant difference between the two groups in terms of usage rate of the punches with different diameters (P = .296). CONCLUSION: The incidence of SV graft patency does not seem to increase in patients whose 4.8-mm aortic punch was used during proximal anastomosis compared to the reference group in which a punch of 4.0 mm was used. Also, the final proximal anastomosis graft size that was measured using cCTA was similar between patients with 4.8-mm punch and patients with 4-mm punch. Results from this study could help to determine which size for aortosaphenous anastomosis is clinically optimal.

Role of thrombophilia factors in acute systemic-pulmonary shunt obstruction.

BACKGROUND: Systemic-pulmonary shunts are widely used in initial palliation in cyanotic congenital heart disease. The incidence and the relationship between acute shunt obstruction and thrombophilia are not precisely defined. The aim of this study was to determine the frequency of shunt obstruction in the early postoperative period, and to define the frequency and presence of thrombophilia factors in patients treated for acute shunt thrombosis. METHODS: Between October 2010 and October 2012, 77 patients who had systemic-pulmonary shunt operation were included in this prospective study. Patients who developed shunt obstruction were examined in terms of inherited and acquired thrombophilia factors. RESULTS: Median patient age was 61 days and median weight was 4.3 kg. Thirty-three patients were neonates. Diameter of the Gore-Tex grafts used for the shunt ranged from 3 mm to 5 mm. Acute shunt occlusion rate was 10% (8/77), and all of these occurred in the first 24 h. Thrombophilia was found in three of eight patients who underwent intervention (surgical and/or transcatheter) due to shunt thrombosis (presence of anti-phospholipid antibodies, n = 1; protein C deficiency, n = 1; and factor V Leiden mutation, n = 1) and only one patient died. CONCLUSIONS: Acute shunt obstruction developed in 10% of patients who underwent systemic-pulmonary shunt, and emergency surgery or transcatheter intervention can be life saving in this context. Acute shunt obstruction can occur due to mechanical and hemodynamic problems, but clinicians should also consider and evaluate thrombophilia factors.

Factors affecting perioperative mortality in tetralogy of Fallot.

BACKGROUND: We evaluated the preoperative, operative and postoperative risk factors affecting early mortality in patients who underwent total correction of tetralogy of Fallot (TOF). METHODS: One hundred and twenty-two TOF patients who underwent reparative surgery between January 2010 and November 2013 were enrolled in the study. RESULTS: Mean patient age and weight was 2.3 ± 2.5 years and 11.3 ± 6.4 kg, respectively. Cardiac catheterization was performed in 101 patients (83%),and coronary anomalies were found in 11 patients. Mean McGoon index, pulmonary annulus z-score, main pulmonary artery z-score, left pulmonary artery z-score and right pulmonary artery z-score were 2.0 ± 0.4, -1.85 ± 1.54, -2.84 ± 2.06, 1.17 ± 1.73, and 0.74 ± 1.57, respectively. Total reparative surgery with a transannular patch was performed in 97 patients (79.6%); the rest underwent valve-sparing surgery. Median duration of postoperative mechanical ventilation, intensive care and hospital stay were 19 h, 3 days and 9 days, respectively. Extracorporeal membrane oxygenation (ECMO) was required in 10 patients in the postoperative early period. Arrhythmias occurring in the early postoperative period were junctional ectopic tachycardia (n = 13), complete atrioventricular block(n = 10; permanent epicardial pacemaker implanted in four) and ventricular tachycardia (n = 4). Nine patients died in the early postoperative period (7.3%). Parameters found to be associated with increased mortality were low preoperative oxygen saturation; high right ventricular/aortic pressure ratio immediately after surgery; presence of coronary anomaly; requirement of postoperative ECMO; and pacemaker (P = 0.02, P = 0.04, P = 0.01, P = 0.0001, P = 0.03, respectively). CONCLUSIONS: Poor preoperative oxygenation, presence of coronary anomaly, complete AV block in the early postoperative period, high RV pressure and requirement of ECMO appear to be the most significant factors that affect early mortality in the surgical treatment of TOF. Appropriate preoperative assessment, correct surgical strategies and attentive intensive care monitoring are required in order to reduce mortality.

Inverted left atrial appendage in an infant during cardiac surgery.

Inverted left atrial appendage is an unusual complication associated with congenital cardiac surgery. Inversion of the left atrial appendage may occur during the surgical procedure or afterwards. The left atrial appendage may invert iatrogenically or as a result of the negative pressure during placement or removal of the left atrial vent or during deairing manoeuvres. This event can be life-threatening because of the mass effect of the atrial appendage within the left atrial cavity.

Effect of electrocautery on endothelial integrity of the internal thoracic artery: ultrastructural analysis with transmission electron microscopy.

The internal thoracic artery (ITA) is typically harvested from the chest wall by means of conventional electrocautery. We investigated the effects of electrocautery on endothelial-cell and vessel-wall morphology at the ultrastructural level during ITA harvesting. Internal thoracic artery specimens from 20 patients who underwent elective coronary artery bypass grafting were investigated in 2 groups. The ITA grafts were sharply dissected with use of a scalpel and clips in the control group (n=10) and were harvested by means of electrocautery in the study group (n=10). Each sample was evaluated for intimal, elastic-tissue, muscular-layer, and adventitial changes. Free flow was measured intraoperatively. Light microscopic examinations were performed after hematoxylin-eosin and Masson's trichrome staining. Transmission electron microscopy was used to evaluate ultrastructural changes in the endothelial cells and vessel walls of each ITA. In the sharp-dissection group, the endothelial surfaces were lined with normal amounts of original endothelium, endothelial cells were distinctly attached to the basal lamina, cytoplasmic organelles were evident, and intercellular junctional complexes were intact. Conversely, in the electrocautery group, the morphologic integrity of endothelial cells was distorted, with some cell separations and splits, contracted cells, numerous large cytoplasmic vacuoles, and no visible cytoplasmic organelles. The subendothelial layer exhibited disintegration. Free ITA flow was higher in the sharp-dissection group (P=0.04). The integrity of endothelial cells can be better preserved when the ITA is mobilized by means of sharp dissection, rather than solely by electrocautery; we recommend a combined approach.

A rare congenital cardiac anomaly in adulthood: tetralogy of Fallot with absent pulmonary valve syndrome.

In approximately 3% to 6% of the patients with tetralogy of Fallot (TOF), the pulmonary valve leaflets are absent or only a rudimentary ridge of tissue is present. Some infants with the severe form of this syndrome die early during the newborn period due to severe respiratory distress, feeding intolerance, or cardiovascular compromise. Survival to adulthood of this combination is extremely unusual. In this article, we presented a case who was diagnosed in adult age with TOF having absent pulmonary valve syndrome. The patient with these findings underwent surgery, and complete repair was performed. Clinical symptoms resolved after surgery.

The impact of vessel clamps on endothelial integrity and function of saphenous vein grafts.

BACKGROUND: Saphenous vein graft (SVG) failure can be associated with endothelial damage during coronary artery bypass grafting (CABG). Endothelial damage may develop after application of occlusive vessel clamps on SVGs. This study was designed to investigate the effect of plastic and metal clamps on the endothelial integrity and function of SVGs. METHODS: Saphenous vein samples were obtained from 10 consecutive patients, who underwent an elective CABG using SVG. Plastic (group 1) and metal (group 2) clamps were sequentially applied on the vein. Each set of clamps (1 plastic and 1 metal) was removed and sampled at 5, 15, and 30 min, respectively. A short SVG segment was removed as control. The samples were fixed for histopathologic study using hematoxylin-eosin staining and immunostaining for endothelial nitric oxide synthase (eNOS) expression. In each group, endothelial, elastic tissue, muscular layer, and adventitial changes were investigated under light microscope and compared using a histologic scoring system. The intensity of eNOS expression was assessed using histochemical scoring system. RESULTS: In both groups, histopathologic examinations showed progressive endothelial damage in the zones of clamp application, compared with the control group (P<0.001). Histopathologic changes were more favorable with the metal clamps, compared with the plastic clamps, at 5 and 15 min. No significant increase in endothelial damage occurred after 15 min. The eNOS immunoreactivity of SVGs significantly decreased in the damaged areas of the endothelium (P<0.05). In metal clamps, the intensity of eNOS immunostaining was significantly high at 5 min, compared with plastic clamps (P<0.05). However, the intensity of eNOS expression in metal clamps was significantly lower than plastic clamps at 15 min (P<0.05). No significant difference was observed between the groups at 30 min. CONCLUSIONS: The endothelial cells can be better preserved with short-term application of SVGs with metal clamps rather than plastic clamps. These findings suggest that temporary use of metal clamps can be preferred without major effects on vascular integrity and function.

Peroneal nerve palsy caused by popliteal pseudoaneurysm in a child with hereditary multiple exostosis.

A 12-year-old boy with a family history of hereditary multiple exostosis presented with a 3-week history of progressive knee swelling. The clinical examination revealed drop foot and a loss of extension in his right knee. Evaluation with color duplex ultrasonography, computed tomography angiography, and magnetic resonance imaging revealed a popliteal artery pseudoaneurysm associated with exostosis from the distal femur. This patient was diagnosed as having peroneal neuropathy caused by popliteal artery pseudoaneurysm compressing the nerve in the right popliteal fossa. The pseudoaneurysm was repaired primarily, and the exostosis was excised during the operation. Pain and knee contracture resolved after surgery. The patient was then referred to physical therapy for the management of drop foot.

Epicardial adipose tissue is associated with extensive coronary artery lesions in patients undergoing coronary artery bypass grafting: an observational study.

OBJECTIVES: To investigate the relationship between the epicardial adipose tissue (EAT) volume measured by 256-slice dual source computed tomography (DSCT) and the complexity with the presence of significant coronary artery disease (CAD) in patients undergoing coronary artery bypass graft surgery (CABG). MATERIAL AND METHODS: Study subjects were enrolled as they were undergoing DSCT for coronary evaluation. Two subgroups were formed according to coronary artery bypass history: Group A (patients with significant CAD), Group B (patients with normal coronary arteries). In both groups, EAT volume was measured by DSCT with the same technique. The complexity of CAD was assessed by using Syntax score (SxS). Group A patients were subdivided into two groups according to these results (Group A1, A2). OUTCOMES: Ninety-three patients (53 male, 40 female) with a mean age of 55.1 years were enrolled in the study (48 in group A and 45 in Group B). The serum levels of fasting plasma glucose (FPG), total cholesterol (TC) and low-density lipoprotein (LDL) were found statistically higher in Group A. In Group A, mean EAT volume was 44.87±21.28 cm(3) while it was in normal range (32.37±17.50 cm(3)) in control group (p=0.003). Higher EAT volume was found to be related to FPG (r=0.242, p=0.015) and body surface area (BSA) (r =0.268, p=0.009) and also correlated positively with CAD. On the other hand, there was no significant difference between subgroups when considering the complexity of CAD. CONCLUSIONS: Our data shows that increased EAT volume is associated with significant CAD. EAT volume contributes to the development of coronary lesions, but it does not affect the complexity of the lesions.

Clinical outcome of patients in a start-up congenital heart surgery program in Turkey.

This study summarizes the clinical outcome data of a start-up congenital heart surgery program in Turkey. Between December 2009 and February 2012, 616 operations have been performed in 132 newborns (22%), 260 infants (42%), and 224 children/adolescents (36%). Risk adjustment analysis was performed using the risk adjustment in congenital heart surgery (RACHS-1) risk assessment model. There were 66 mortalities (10.7%). According to the RACHS-1 categories, there were 51 cases in level I (8.2%) with no mortality (0%), 250 in level II (40.6%) with 11 (4.4%) mortalities, 199 in level III (32.3%) with 33 (16.5%) mortalities, 53 in level IV (8.6%) with 10 (18.8%) mortalities, 14 in level V and VI (2.2%) with 11 (78.5%) mortalities, and 49 cases (7.9%) out of the RACHS-1 categories with one (2.0%) mortality. Mortality was higher in neonates compared to infants, and in infants compared to children/adolescents. Mortality was higher in palliative procedures compared to corrective procedures. The data demonstrate that a start-up program with a relatively loaded surgical volume may achieve acceptable clinical results with a good teamwork. Collaboration of anesthesiologists, perfusionists, pediatric cardiologists, intensivists, and cardiovascular surgeons is necessary to provide a better outcome in congenital heart surgery.

Extracorporeal life support experiences of a new congenital heart center in Turkey.

Extracorporeal life support (ECLS) provides mechanical support following cardiac surgery when respiratory and cardiac failure occurs. We retrospectively reviewed medical records of patients who needed ECLS at a new congenital heart center in Turkey. Between December 2009 and February 2012, 616 congenital heart operations were performed. A total of 13 patients (seven female) underwent ECLS. The ages of the patients ranged between 16 days and 33 years. There were two neonatal, seven infant, three pediatric, and one adult congenital cases. Medos DPII ECLS system was used in all patients. Mean duration of ECLS was 6.2 ± 5.8 days (ranged from 29 h to 24 days). While central vascular access with aorta and right atrial cannulation was used in 11 patients, neck vessels were used in the other patients. Four patients (30.7%) weaned successfully from ECLS (two infant, two pediatric cases). Three of them had ECLS intraoperatively. In all patients, two (15.4%) were discharged from the hospital. One of them had mild neurologic deficit. Bleeding from the surgical and cannulation sites was the most common complication. Thrombus was detected in pump head and changed uneventfully in three patients. Arterial pH and lactate levels at the beginning of ECLS were significantly lower in patients who were successfully weaned from ECLS than nonsurvivors (P = 0.04 and P = 0.02, respectively). ECLS can be a lifesaving modality in the perioperative period. It may be more beneficial if ECLS is used before the development of severe acidosis and high lactate levels.

Cerebral perfusion during cardiopulmonary bypass in children: correlations between near-infrared spectroscopy, temperature, lactate, pump flow, and blood pressure.

Near-infrared spectroscopy (NIRS) is a noninvasive modality to monitor regional brain oxygenation (rSO(2) ). In this study, we aimed to investigate the correlation between cerebral rSO(2) and lactate, pump flow, hematocrit, pCO(2) , and mean blood pressure (MBP) during cardiopulmonary bypass (CPB). Between March and September 2011, 50 pediatric patients who underwent congenital heart surgery were enrolled into the study. Ages ranged from 6 days to 168 months (median 14 months). A NIRS sensor (Somanetics 5100B, Troy, MI, USA) was placed on the right forehead of patients. CPB period was divided into five stages: 1-at the beginning of CBP, 2-cooling at 32°C, 3-at final hypothermic temperature, 4-rewarming at 32°C, 5-before weaning from CPB. Data collection included measurements of each parameter at five stages of CPB. Data were analyzed using multivariate analysis within groups and Spearman's correlation to test association between parameters. Lactate levels increased significantly from stage 1 to stage 5 during CPB (P < 0.05). There was no significant correlation between cerebral rSO(2) and MBPs, pump flows, hematocrit, or pCO(2) during CPB. Cerebral rSO(2) levels showed changes between the stages; there was a significant increase during cooling period, compared to stage 1 (P < 0.05). Significant changes during cooling stage did not happen for other parameters. At stage 3, there was a negative correlation between lactate level and MBP. At stage 4, there was no significant change in cerebral rSO(2) levels despite decreased MBP. At the warming stage, low MBPs, but normal rSO(2) values, are observed despite increased pump flows. Increased rSO(2) levels despite insignificant changes at other parameters during the cooling stage of CPB may show that optimal pump flow with adequate intravascular volume may provide effective cerebral perfusion even without changes in MBP. Considering normal rSO(2) values during CPB in this study, it may be speculated that brain protection can be assessed by using NIRS and applying a standard bypass protocol.