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Dean B Andropoulos

Publications and source records attributed to Dean B Andropoulos.

At least 19 recordsLinked to original sources
PubMed2006

Bilateral monitoring of cerebral oxygen saturation results in recognition of aortic cannula malposition during pediatric congenital heart surgery.

Congenital heart surgery is associated with a 2-25% reported incidence of neurological complication. Near-infrared spectroscopy (NIRS) can detect changes in regional cerebral saturation index (rSO2i) during cardiac surgery. If rSO2i decreases significantly, treatment algorithms are used to restore baseline values, potentially avoiding neurological complications. The efficacy of bilateral NIRS monitoring in pediatric congenital heart surgery has been debated. We report a case in which bilateral NIRS monitoring detected an abrupt decrease in rSO2i (right greater than left) after initiation of bypass without abnormalities detected by standard monitors. This resulted in prompt surgical intervention that restored rSO2i, potentially preventing neurological injury.

Brain Chemistry↗
PubMed2005

Congenital heart surgery 2005: the brain: it's the heart of the matter.

Operative mortality after repair of even the most complex congenital heart lesions has become rare. As such, the gaze of the surgical team has been diverted beyond that of early survival to focus on decreasing early and late morbidity. Important and concerning information is accumulating delineating the vulnerability of the neonatal brain to injury as the result of congenital heart disease and/or the techniques employed to correct the lesions. For many years the prevention of neurologic injury associated with congenital heart surgery has concentrated on "unraveling" the mysteries of the deleterious effects of intentional brain ischemia (in the form of deep hypothermic circulatory arrest) and developing methods to interrupt the pathway of irreversible injury. In the late 1990s, alternative perfusion techniques were developed to minimize or theoretically avoid the use of deep hypothermic circulatory arrest where it was once thought to be mandatory. Simultaneously, the rather routine use of noninvasive, real-time, neurologic monitoring has provided surgical teams the opportunity to intervene and prevent brain injury , thus eliminating the historic reliance on postoperative surrogate markers to define the presence of brain injury. It is yet undetermined whether these strategies will translate into improved short- and long-term neurologic outcome. Common to all surgical disciplines is a trend that as mortality decreases for a particular disease process, focus is adjusted, and refinements in treatment protocols are designed to minimize morbidity of the disease and its treatment. This natural refining process of a discipline's maturation is increasingly present in the field of congenital heart surgery.

Cardiac Surgical Procedures↗
PubMed2005

New developments in pediatric cardiac anesthesia.

As the practice of pediatric cardiac anesthesia continues to grow, anesthesiologists now routinely care for patients ranging in size from less than 2 kg to more than 100 kg. New clinical and laboratory research has enhanced our understanding of the effects of anesthetic drugs on the pediatric myocardium, and improvements in survival statistics for even the smallest and sickest infants have shifted the emphasis to evaluation of quality of life and neurological outcome in pediatric cardiac patients. The use of circulatory support in infants and children, both for rapid resuscitation and for more chronic indications such as bridge to transplantation, also continues to evolve, with the recent introduction of pulsatile and axial pumps for pediatric use. This article reviews anesthetic agents, bleeding and coagulation, neurological monitoring, and mechanical circulatory support in the treatment of infants and children.

Anesthesia↗
PubMed2005

Anesthetic management and outcome of complex late arterial-switch operations for patients with transposition of the great arteries and a systemic right ventricle.

OBJECTIVE: For patients with transposition of the great arteries and a systemic right ventricle, complex late arterial-switch operations (double switch, switch conversion, Senning-Rastelli) after the newborn period have been described recently to restore the morphologic left ventricle to the systemic circulation. The purpose of this study was to describe the anesthetic management and perioperative outcome of this group of patients and to compare them with a control group of patients who had primary arterial-switch operations in the neonatal period. DESIGN: Retrospective database and medical record review with 3:1 control:case ratio. SETTING: Tertiary care academic children's hospital. PARTICIPANTS: Patients undergoing complex late-arterial switch operations after the newborn period. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Thirteen patients were identified in the complex late-switch group and 43 in neonatal arterial-switch group. There were no perioperative deaths, no new gross neurologic deficits, and all patients were discharged home in both groups. Anesthetic and bypass times were significantly longer in the late-switch group (745 v 558 minutes, p < 0.001, and 382 v 243 minutes, p < 0.001, respectively). Transfusion requirements were similar between the groups. The incidence of arrhythmia (92% v 9%, p < 0.001), use of pacing systems (69% v 9%, p < 0.001), cardioversion (15% v 0%, p = 0.05), and pharmacologic treatment of arrhythmias (69% v 0%, p < 0.01) intraoperatively were significantly higher in the complex late-switch group. CONCLUSIONS: Patients presenting for complex late corrective operations for transposition of the great arteries require long and complex anesthetics. Despite these challenges, perioperative outcomes are excellent.

Adolescent↗
PubMed2005

A noninvasive estimation of mixed venous oxygen saturation using near-infrared spectroscopy by cerebral oximetry in pediatric cardiac surgery patients.

BACKGROUND: Near-infrared spectroscopy (NIRS) is a noninvasive optical monitor of regional cerebral oxygen saturation (rSO2). The aim of this study was to validate the use of NIRS by cerebral oximetry in estimating invasively measured mixed venous oxygen saturation (SvO2) in pediatric postoperative cardiac surgery patients. METHODS: Twenty patients were enrolled following cardiac surgery with intraoperative placement of a pulmonary artery (PA) or superior vena cava (SVC) catheter. Five patients underwent complete biventricular repair--complete atrioventricular canal (n=3) and other (n=2). Fifteen patients with functional single ventricle underwent palliative procedures--bidirectional Glenn (n=11) and Fontan (n=4). Cerebral rSO2 was monitored via NIRS (INVOS 5100) during cardiac surgery and 6 h postoperatively. SvO2 was measured from blood samples obtained via an indwelling PA or SVC catheter and simultaneously correlated with rSO2 by NIRS at five time periods: in the operating room after weaning from cardiopulmonary bypass, after sternal closure, and in the CICU at 2, 4, and 6 h after admission. RESULTS: Each patient had five measurements (total=100 comparisons). SvO2 obtained via an indwelling PA or SVC catheter for all patients correlated with rSO2 obtained via NIRS: Pearson's correlation coefficient of 0.67 (P<0.0001) and linear regression of r2=0.45 (P<0.0001). Separate linear regression of the complete biventricular repairs demonstrated an r=0.71, r2=0.50 (P<0.0001). Bland-Altman analysis showed a bias of +3.3% with a precision of 16.6% for rSO2 as a predictor of SvO2 for all patients. Cerebral rSO2 was a more accurate predictor of SvO2 in the biventricular repair patients (bias -0.3, precision 11.8%), compared with the bidirectional Glenn and Fontan patients. CONCLUSIONS: Regional cerebral oximetry via NIRS correlates with SvO2 obtained via invasive monitoring. However, the wide limits of agreement suggest that it may not be possible to predict absolute values of SvO2 for any given patient based solely on the noninvasive measurement of rSO2. Near-infrared spectroscopy, using the INVOS 5100 cerebral oximeter, could potentially be used to indicate trends in SVO2, but more studies needs to be performed under varying clinical conditions.

Brain Chemistry↗
PubMed2005

Tracheoesophageal fistula and associated congenital heart disease: implications for anesthetic management and survival.

BACKGROUND: Infants with tracheoesophageal fistula (TEF) and/or esophageal atresia (EA) frequently have other associated congenital anomalies which can have a significant impact on their anesthetic care and survival to discharge. METHODS: A medical record review and retrospective data analysis were performed in a university affiliated children's hospital of all infants undergoing TEF/EA repair between January 1998 and July 2004. The incidence of intraoperative complications during the TEF repair and overall survival to hospital discharge was compared in two groups of infants: 26 patients with TEF/EA and coexisting congenital heart disease (CHD), and 27 patients with TEF/EA and no CHD. RESULTS: The overall incidence of intraoperative critical events during repair of TEF/EA was significantly higher in infants with associated cardiac pathology (P = 0.003). Six of 53 infants died during hospitalization (overall mortality, 11.3%) and all had associated cardiac pathology. In comparison with nonductal-dependent lesions, the presence of a ductal-dependent cardiac lesion appeared to significantly increase patient mortality (57% vs. 10%, P = 0.028). CONCLUSIONS: Low birth weight (<1500 g) and associated cardiac pathology were found to be independent predictors of mortality in infants undergoing surgery for TEF/EA repair. The presence of a ductal-dependent cardiac lesion further increased the risk of morbidity and mortality, in addition to necessitating special anesthesia considerations.

Anesthesia, General↗
PubMed2004

Improved early results with the Fontan operation in adults with functional single ventricle.

BACKGROUND: A growing number of adults with functional single ventricles are presenting as candidates for first-time and redo-Fontan operations. This study describes the clinical presentation and early operative results of adults who have undergone Fontan modifications. METHODS: Between July 1995 and April 2003, 23 patients (>18 years old) had Fontan operations. We retrospectively reviewed their perioperative courses. RESULTS: Twenty-three Fontan operations (first-time [n = 8] and redo [n = 15]) were performed with no early or late deaths. No patient has required reoperation. One patient has been listed for orthotopic heart transplantation. The overall mean age is 23 years (18 to 41 years); mean follow-up, 30 months; median postoperative hospital stay, 8 days (4 to 34 days); and median duration of chest tube drainage, 4 days (2 to 12 days). The postoperative New York Heart Association (NYHA) functional class was improved in 22 of 23 patients. Eight first-time Fontan operations (7 of 8 nonfenestrated) were performed; lateral tunnel (n = 7) and extracardiac conduit (n = 1). Two patients had preoperative arrhythmias. New onset arrhythmias (ventricular tachycardia and sinus node dysfunction), requiring treatment, occurred in two patients. Fifteen redo-Fontan operations (all nonfenestrated) were performed; lateral tunnel (n = 5) and extracardiac conduit (n = 10). Fifteen patients had preoperative arrhythmias, thirteen of which had intraatrial reentry tachycardia (IART) and required antiarrhythmic medications. Concomitant intraoperative radiofrequency ablation (RFA) (n = 11) and cryoablation (n = 1) procedures were performed. In the immediate postoperative period, there was IART recurrence in five patients (post-RFA [n = 4] and postcryoablation [n = 1]). At latest follow-up, no patient is being treated with antiarrhythmic medications. Two patients had new onset atrial arrhythmias that required treatment. CONCLUSIONS: The Fontan operation can be performed in adults with minimal morbidity and improved NYHA functional class. New onset arrhythmias requiring treatment are sources of perioperative morbidity. Complete arrhythmia resolution of the preoperative arrhythmia may not be achieved in the immediate postoperative period in redo-Fontan patients. However, modification (intraoperative radiofrequency ablation-right atrial debulking) of the atrial tachycardia circuits in the redo-Fontan patients can result in complete resolution of preoperative atrial tachyarrhythmias at early follow-up.

Adolescent↗
PubMed2004

Neurologic monitoring for special cardiopulmonary bypass techniques.

Low flow hypothermic cardiopulmonary bypass, deep hypothermic circulatory arrest, and regional low-flow cerebral perfusion are special techniques used to facilitate complex intracardiac and aortic surgery in neonates and infants. Each carries a risk of cerebral hypoxia and neurologic morbidity. Neurologic monitoring in the form of near-infrared spectroscopy for cerebral oxygenation, transcranial Doppler ultrasound, and the bispectral index electroencephalogram can monitor the brain during these techniques to determine the minimum acceptable bypass flow rates or maximum acceptable duration of deep hypothermic circulatory arrest. The use of this monitoring has the potential to improve long-term neurologic and developmental outcome.

Cardiopulmonary Bypass↗
PubMed2004

Myocardial performance index with sevoflurane-pancuronium versus fentanyl-midazolam-pancuronium in infants with a functional single ventricle.

BACKGROUND: Patients with congenital heart disease characterized by a functional single ventricle make up an increasing number of patients presenting for cardiac or noncardiac surgery. Conventional echocardiographic methods to measure left ventricular function, i.e., ejection fraction, are invalid in these patients because of altered ventricular geometry. Two recently described Doppler echocardiographic modalities, the myocardial performance index and Doppler tissue imaging, can be applied to single-ventricle patients because they are independent of ventricular geometry. This study assessed the changes in myocardial performance index and Doppler tissue imaging in response to two anesthetic regimens, fentanyl-midazolam-pancuronium and sevoflurane-pancuronium. METHODS: Thirty patients aged 4-12 months with a functional single ventricle were randomized to receive fentanyl-midazolam or sevoflurane. Myocardial performance index and Doppler tissue imaging were measured by transthoracic echocardiography at baseline and two clinically relevant dose levels. RESULTS: Sixteen patients receiving sevoflurane and 14 receiving fentanyl-midazolam were studied. Myocardial performance index was unchanged from baseline with either agent (fentanyl-midazolam: 0.50 +/- 15 baseline vs. 0.51 +/- 0.15 at dose 2; sevoflurane: 0.42 +/- 0.14 baseline vs. 0.46 +/- 0.09 at dose 2). Doppler tissue imaging S (systolic)- and E (early diastolic)-wave velocities in the lateral ventricular walls at the level of the atrioventricular valve annulus were unchanged in the sevoflurane group; however, both Doppler tissue imaging S- and E-wave velocities were decreased significantly from baseline at dose 1 and dose 2 with fentanyl-midazolam, consistent with decreased longitudinal systolic and diastolic ventricular function. CONCLUSIONS: Myocardial performance index, a global measurement of combined systolic and diastolic ventricular function, is not affected by commonly used doses of fentanyl-midazolam or sevoflurane in infants with a functional single ventricle.

Anesthetics, Inhalation↗
PubMed2004

Outcomes of congenital heart surgery patients after extracorporeal life support at Texas Children's Hospital.

The objective of this study was to investigate the outcomes of children with heart failure of various etiologies requiring temporary use of currently available technology in the U.S.A. after extracorporeal life support (ECLS) [left ventricular assist device (LVAD) or extracorporeal membrane oxygenation (ECMO)] at Texas Children's Hospital. Between July of 1995 and October of 2002, 2847 patients underwent congenital heart surgical repairs with the aid of cardiopulmonary bypass at Texas Children's Hospital. During this period, 17 patients required chronic mechanical circulatory assistance with Biomedicus centrifugal pump (n=8) or Thoratec LVAD (n=4), and ECMO (n=5). Six out of 17 patients required ECLS for postcardiotomy heart failure. Seven of the 17 patients had congenital heart disease, six had cardiomyopathy, three had late acute rejection following heart transplantation, and one had myocardial infarction. Twelve patients survived and five patients expired. Six of 12 survivors recovered sufficient cardiac function to allow device removal; and the remaining six patients underwent heart transplantation. Three out of five deaths were ECMO patients. The need for ECLS following repair of congenital heart disease is extremely rare in our institution. The requirement for the use of ECMO confers a significantly higher mortality presumably because of associated combined cardiopulmonary failure. Congenital heart disease appears to be associated with significantly higher mortality.

Adolescent↗
PubMed2004

Changes in respiratory mechanics among infants undergoing heart surgery.

UNLABELLED: Children with excessive pulmonary blood flow (PBF) from congenital heart disease have abnormal respiratory mechanics. Exposure to hypothermic cardiopulmonary bypass (CPB) adversely affects lung function. We designed this study of 106 patients to determine the changes in respiratory mechanics in infants younger than 1 yr undergoing heart surgery. Dynamic respiratory compliance (Cdyn) and total respiratory resistance (Rrs) were measured before surgical incision, after sternal closure in the operating room, and after arrival in the intensive care unit. The following data were recorded: age, weight, preoperative pulmonary infiltrates, preoperative mechanical ventilation, evidence of increased PBF before surgery, duration of CPB, duration of aortic cross-clamp, duration of deep hypothermic circulatory arrest, use of steroids, and volume of ultrafiltrate removed. Repeated-measures analysis of variance with covariate analysis was used to determine the effect of each covariate on Cdyn and Rrs at the three time periods. Rrs improved after cardiac surgery correcting increases in PBF, and this was most pronounced in neonates. Among infants with normal or reduced PBF, cardiac surgery with CPB led to a reduction in Cdyn. We consider that the benefits of surgical correction of pulmonary overcirculation outweigh the negative effects of CPB on respiratory mechanics. IMPLICATIONS: The benefits of surgical correction of pulmonary overcirculation outweigh the negative effects of cardiopulmonary bypass on respiratory mechanics in infants.

Aging↗
PubMed2004

Is bilateral monitoring of cerebral oxygen saturation necessary during neonatal aortic arch reconstruction?

UNLABELLED: In this study, we measured cerebral oxygenation in both cerebral hemispheres by using near-infrared spectroscopy before, during, and after regional low-flow cerebral perfusion (RLFP) to determine whether bilateral monitoring was necessary. Neonates undergoing aortic arch reconstruction with RLFP were studied. The bilateral regional cerebral oxygenation index was measured and recorded at 1-min intervals during the following periods: 1) before bypass, 2) during bypass before RLFP, 3) during RLFP, 4) on bypass after RLFP, and 5) post-bypass. Before bypass and on bypass before RLFP, the correlation (r = 0.979 and 0.852) and agreement (mean bias, right versus left, 0 and +2) between hemispheres were excellent. During RLFP, however, correlation (r = 0.35) and agreement (mean bias of the right versus left side, +6.3) worsened and only partially returned to baseline values after RLFP. Nine of 19 patients had sustained differences in cerebral oxygen saturation of >10%, always with the left side values less than the right. Bilateral monitoring detects desaturation in the left cerebral hemisphere during RLFP. The long-term consequences of lower saturations on the left side of the brain are unclear. IMPLICATIONS: Left-sided cerebral hemisphere oxygen saturation, measured with near-infrared spectroscopy, was less than right-sided cerebral oxygen saturation during regional low-flow cerebral perfusion used for neonatal aortic arch reconstruction.

Aorta, Thoracic↗
PubMed2004

Neurological monitoring for congenital heart surgery.

The incidence of neurological complications after pediatric cardiac surgery ranges from 2% to 25%. The causes are multifactorial and include preoperative brain malformations, perioperative hypoxemia and low cardiac output states, sequelae of cardiopulmonary bypass, and deep hypothermic circulatory arrest. Neurological monitoring devices are readily available and the anesthesiologist can now monitor the brain during pediatric cardiac surgery. In this review we discuss near-infrared cerebral oximetry, transcranial Doppler ultrasound, and electroencephalographic monitors for use during congenital heart surgery. After review of the basic principles of each monitoring modality, we discuss their uses during pediatric heart surgery. We present evidence that multimodal neurological monitoring in conjunction with a treatment algorithm may improve neurological outcome for patients undergoing congenital heart surgery and present one such algorithm.

Adolescent↗
PubMed2004

Limiting circulatory arrest using regional low flow perfusion.

Deep hypothermic circulatory arrest (DHCA) is commonly used for neonatal cardiac surgery. However, prolonged exposure to DHCA is associated with neurologic morbidity. The Norwood operation and aortic arch advancement are procedures that typically require DHCA during surgical correction. Regional low flow perfusion (RLFP) can be used to limit or exclude the use of circulatory arrest. This technique involves cannulation of the innominate or subclavian artery using a Gore-Tex graft, allowing isolated cerebral perfusion. Data was collected in 34 patients undergoing either neonatal aortic arch reconstruction or the Norwood procedure using RLFP. All patients had two arterial pressure monitors using either the umbilical or femoral artery catheters and radial or brachial catheters. Adequacy of perfusion was determined using cerebral saturation, blood flow velocity, mean arterial pressures, and arterial blood gas results. Cerebral saturation and blood flow velocity were monitored using the near-infrared spectroscopy (NIRS) (INVOS 5100, Somanetics Corp, Troy, MI) and a transcranial Doppler pulse-wave ultrasound (TCD) (EME Companion, Nicolet Biomedical, Madison, WI), respectively throughout the entire bypass period. Blood gases were monitored using a point of care blood gas analyzer (Gem Premier, Mallinckrodt Sensor System, Inc., Ann Arbor, MI). Data collected revealed total bypass times for repair between 69-348 min, with a mean of 180 min. Regional low flow perfusion times lasted between 6-158 min, with an average of 50 min., and DHCA times ranged from 0-66 min, with a mean of 19 min. The perfusion techniques used allowed patient clinical data to remain consistent throughout the cardiopulmonary bypass period, regardless of lower flows (Figure 1) The 30-day postoperative mortality rate was 2.9 %, with no evidence of neurologic injury during follow up. In conclusion, regional low flow cerebral perfusion might benefit patients by limiting the use of circulatory arrest during cardiac surgery. Further study is necessary to evaluate patient outcomes, comparing regional cerebral perfusion and circulatory arrest techniques.

Anastomosis, Surgical↗
PubMed2003

Regional low-flow perfusion provides comparable blood flow and oxygenation to both cerebral hemispheres during neonatal aortic arch reconstruction.

OBJECTIVE: The aim of this study was to measure cerebral oxygenation, cerebral blood volume index, and cerebral blood flow velocity values in both cerebral hemispheres before, during, and after regional low-flow cerebral perfusion for neonatal aortic arch reconstruction and to test the hypothesis that cerebral blood volume index measured by near infrared spectroscopy correlates with cerebral blood flow velocity measured by transcranial Doppler ultrasonography. METHODS: Bilateral near infrared spectroscopy and transcranial Doppler ultrasonography sensors were placed, and values were recorded immediately before, during, and after regional low-flow cerebral perfusion at 18 degrees C. Cerebral oxygen saturations, cerebral blood flow velocities, and cerebral blood volume index values were compared by Mann-Whitney U test. Correlations between values of cerebral blood volume index and cerebral blood flow velocity were tested with Spearman rank order correlation. RESULTS: Twenty patients were studied. Median cerebral oxygen saturations for the right and left sides were 95% and 95% before regional low-flow cerebral perfusion, 95% and 87% during regional low-flow cerebral perfusion (P =.054), and 93% and 94% after regional low-flow cerebral perfusion. Median cerebral blood flow velocity values did not change during regional low-flow cerebral perfusion. Cerebral blood volume index exhibited a poor correlation with cerebral blood flow velocity. CONCLUSIONS: Regional low-flow cerebral perfusion provides comparable blood flows and oxygenation to both cerebral hemispheres. Transcranial Doppler ultrasonography is recommended as a corroborative method with near-infrared spectroscopy to guide flow during regional low-flow cerebral perfusion, because cerebral blood volume index does not correlate with cerebral blood flow velocity.

Aorta, Thoracic↗
PubMed2003

Anesthetic management of the adult patient with congenital heart disease.

As the number of CHD repairs in adults continues to increase, these operations will be performed in a wider variety of institutions and systems. Unfortunately, not all of these centers will have an optimal environment for correcting CHD in adults. This type of surgery is best accomplished in a facility specifically designed for treating adults with CHD. Optimal care of these patients is provided by cardiologists who are trained and experienced in pediatric and adult cardiology, by surgeons who are trained and experienced in treating CHD, and by anesthesiologists who are experienced in caring for adults with CHD. Whatever the setting, cardiac anesthesiologists involved in these cases must be thoroughly aware of the anesthetic implications for the unique pathophysiology of each patient, and they must not rely on their "usual" expectations of either true pediatric CHD or acquired adult heart disease.

Adult↗
PubMed2003

Novel cerebral physiologic monitoring to guide low-flow cerebral perfusion during neonatal aortic arch reconstruction.

OBJECTIVE: This study was undertaken to describe the combined measurement of cerebral blood flow velocity and cerebral oxygen saturation as a guide to bypass flow rate for regional low-flow perfusion during neonatal aortic arch reconstruction. METHODS: Data were prospectively collected from 34 patients undergoing neonatal aortic arch reconstruction with regional low-flow perfusion. Cerebral oxygen saturation and blood flow velocity were measured by near-infrared spectroscopy and transcranial Doppler ultrasonography, respectively, throughout cardiopulmonary bypass. After cooling to 17 degrees C to 22 degrees C, baseline values of cerebral oxygen saturation and blood flow velocity were recorded during full-flow bypass. Regional low-flow perfusion was instituted for aortic arch reconstruction, and bypass flow rate was adjusted to maintain cerebral oxygen saturations and blood flow velocities within 10% of baseline recorded during cold full-flow bypass. Cerebral oxygen saturations and blood flow velocities were recorded again after repair during full-flow hypothermic bypass. Bypass flow during regional low-flow perfusion was recorded, as were arterial pressure and blood gas data. One-way repeated measures analysis of variance was used to determine differences in values during regional low-flow perfusion relative to baseline and after perfusion. RESULTS: A mean bypass flow of 63 mL/(kg x min) was required to maintain cerebral oxygen saturations and blood flow velocities within 10% of baseline. Mean arterial pressure had a poor correlation with the required bypass flow rate (r(2) = 0.006 by linear regression analysis). Fourteen of 34 patients had a cerebral oxygen saturation of 95% during regional low-flow perfusion, placing them at risk for cerebral hyperperfusion if the cerebral oxygen saturation had been used alone to guide bypass flow. Pressure was detected in the umbilical or femoral artery catheter (mean 12 mm Hg) in all patients during regional low-flow perfusion. CONCLUSIONS: Cerebral blood flow velocity, as determined by transcranial Doppler ultrasonography, adds valuable information to cerebral oxygen saturation data in guiding bypass flow during regional low-flow perfusion. Its most important use may be prevention of cerebral hyperperfusion during periods with high near-infrared spectroscopic saturation values.

Analysis of Variance↗