Acute Hemodynamics in the Fontan Circulation: Open-Label Study of Vasopressin.

OBJECTIVE: To describe the acute hemodynamic effect of vasopressin on the Fontan circulation, including systemic and pulmonary pressures and resistances, left atrial pressure, and cardiac index. DESIGN: Prospective, open-label, nonrandomized study (NCT04463394). SETTING: Cardiac catheterization laboratory at Lucile Packard Children's Hospital, Stanford. PATIENTS: Patients 3-50 years old with a Fontan circulation who were referred to the cardiac catheterization laboratory for hemodynamic assessment and/or intervention. INTERVENTIONS: A 0.03 U/kg IV (maximum dose 1 unit) bolus of vasopressin was administered over 5 minutes, followed by a maintenance infusion of 0.3 mU/kg/min (maximum dose 0.03 U/min). MEASUREMENTS AND MAIN RESULTS: Comprehensive cardiac catheterization measurements before and after vasopressin administration. Measurements included pulmonary artery, atrial, and systemic arterial pressures, oxygen saturations, and systemic and pulmonary flows and resistances. There were 28 patients studied. Median age was 13.5 (9.1, 17) years, and 16 (57%) patients had a single or dominant right ventricle. Following vasopressin administration, systolic blood pressure and systemic vascular resistance (SVR) increased by 17.5 (13.0, 22.8) mm Hg ( Z value -4.6, p < 0.001) and 3.8 (1.8, 7.5) Wood Units ( Z value -4.6, p < 0.001), respectively. The pulmonary vascular resistance (PVR) decreased by 0.4 ± 0.4 WU ( t statistic 6.2, p < 0.001), and the left atrial pressure increased by 1.0 (0.0, 2.0) mm Hg ( Z value -3.5, p < 0.001). The PVR:SVR decreased by 0.04 ± 0.03 ( t statistic 8.1, p < 0.001). Neither the pulmonary artery pressure (median difference 0.0 [-1.0, 1.0], Z value -0.4, p = 0.69) nor cardiac index (0.1 ± 0.3, t statistic -1.4, p = 0.18) changed significantly. There were no adverse events. CONCLUSIONS: In Fontan patients undergoing cardiac catheterization, vasopressin administration resulted in a significant increase in systolic blood pressure, SVR, and left atrial pressure, decrease in PVR, and no change in cardiac index or pulmonary artery pressure. These findings suggest that in Fontan patients vasopressin may be an option for treating systemic hypotension during sedation or general anesthesia.

Clinical Study of Continuous Non-Invasive Blood Pressure Monitoring in Neonates.

The continuous monitoring of arterial blood pressure (BP) is vital for assessing and treating cardiovascular instability in a sick infant. Currently, invasive catheters are inserted into an artery to monitor critically-ill infants. Catheterization requires skill, is time consuming, prone to complications, and often painful. Herein, we report on the feasibility and accuracy of a non-invasive, wearable device that is easy to place and operate and continuously monitors BP without the need for external calibration. The device uses capacitive sensors to acquire pulse waveform measurements from the wrist and/or foot of preterm and term infants. Systolic, diastolic, and mean arterial pressures are inferred from the recorded pulse waveform data using algorithms trained using artificial neural network (ANN) techniques. The sensor-derived, continuous, non-invasive BP data were compared with corresponding invasive arterial line (IAL) data from 81 infants with a wide variety of pathologies to conclude that inferred BP values meet FDA-level accuracy requirements for these critically ill, yet normotensive term and preterm infants.

Bronchopulmonary dysplasia.

Bronchopulmonary dysplasia is the most frequent adverse outcome of prematurity. Before implementation of antenatal steroids and surfactant therapy, bronchopulmonary dysplasia was mostly characterized by fibrotic, scarred, and hyper-inflated lungs due to pulmonary injury following mechanical ventilation and oxygen toxicity. With advances in neonatal medicine, this "old" bronchopulmonary dysplasia has changed to a "new" bronchopulmonary dysplasia characterized by an arrest in lung growth, leading to alveolar simplification and pulmonary vascular dysangiogenesis. While the old definition was based on the need for oxygen supplementation at a postnatal age of 28 days or at a corrected gestational age of 36 weeks, the newer definition looks at the mode of respiratory support required (eg, invasive versus noninvasive) and is then graded as mild, moderate, or severe. Patients with bronchopulmonary dysplasia may present with significantly impaired pulmonary function, reactive airway disease, or exercise intolerance. Over time, these patients may develop asthma or chronic obstructive pulmonary disease. The most serious long-term complication is the development of pulmonary vascular disease and pulmonary hypertension. Medical treatment often includes diuretics, steroids, bronchodilators, or oxygen supplementation and in the presence of pulmonary hypertension medication to decrease the pulmonary vascular resistance. Perioperative anesthetic risk is increased in children with pulmonary hypertension. These patients might require additional diagnostic imaging and plans for increased resource allocation such as postoperative intensive care admission.

Impact of Modified Anesthesia Management for Pediatric Patients With Williams Syndrome.

OBJECTIVE: This study compared the percent change in systolic blood pressure and the incidence of adverse cardiac events (ACEs; defined as cardiac arrest, cardiopulmonary resuscitation, arrhythmias, or ST-segment changes) during anesthesia induction in patients with Williams syndrome (WS) before and after implementation of a perioperative management strategy. DESIGN: Retrospective observational cohort study. SETTING: Single quaternary academic referral center. PARTICIPANTS: The authors reviewed the records of all children with WS at the authors' institution who underwent general anesthesia for cardiac catheterization, diagnostic imaging, or any type of surgery between November 2008 and August 2019. The authors identified 142 patients with WS, 48 of whom underwent 118 general anesthesia administrations. A historic group (HG) was compared with the intervention group (IG). INTERVENTIONS: Change in perioperative management (three-stage risk stratification: preoperative intravenous hydration, intravenous anesthesia induction, and early use of vasoactives). MEASUREMENTS AND MAIN RESULTS: The authors determined event rates within 60 minutes of anesthesia induction. Standardized mean difference (SMD) was calculated (SMD >0.2 suggests clinically meaningful difference). Sixty-seven general anesthesia encounters were recorded in the HG (mean age, 4.8 years; mean weight, 16.3 kg) and 51 in the IG (mean age, 6.0 years; mean weight, 18.2 kg). The change in systolic blood pressure was -17.5% (-30.0, -5.0) in the HG versus -9% (-18.0, 5.0) in the IG (p = 0.015; SMD = 0.419), and the incidence of ACEs was 6% in the HG and 2% in the IG (p = 0.542; SMD = 0.207). CONCLUSIONS: Preoperative risk stratification, preoperative intravenous hydration, intravenous induction, and early use of continuous vasoactives resulted in greater hemodynamic stability, with a 2% incidence of ACEs.

Neurosurgical intervention in children with ventricular assist devices: A single-center case series review.

BACKGROUND: The incidence of neurological complications related to ventricular assist devices (VAD) remains high and includes life-threatening conditions such as intracranial hemorrhage or ischemic stroke. Although no definitive management guidelines exist, operative interventions may be required for major neurological injuries. AIMS: This case series describes the perioperative management of children at a single center who underwent neurosurgical procedures for major intracranial bleeds or ischemic strokes while on VAD support. METHODS: A database review identified all pediatric VAD patients who underwent a neurosurgical procedure for an intracranial hemorrhage or ischemic stroke from April 2014 to January 2020. Data regarding patient characteristics, preoperative medical management, intraoperative anesthetic management, and postoperative outcomes were collected using retrospective chart review. RESULTS: Ninety VADs were implanted in 78 patients. Five neurosurgical interventions were performed: four for intracranial hemorrhages and one for an ischemic stroke. All four patients with hemorrhages were receiving anticoagulation at the time of their event and the three patients on warfarin received emergent reversal with prothrombin concentrate complex and vitamin K. Three patients also received pre-procedural platelet transfusions. Two of the five procedures were emergent bedside external ventricular drain placements, and three were surgical operations. All three patients who underwent operative procedures received invasive hemodynamic monitoring and were supported with a combination of inotropes and afterload reduction. One patient required a massive blood product transfusion. The two patients who underwent external ventricular drain placement had no further surgical interventions and died from the severity of their neurological injuries. All three patients who underwent operative procedures survived to transplantation and discharge home. CONCLUSIONS: Perioperative concerns for the anesthesiologist include VAD hemodynamic management, bleeding, VAD thrombosis, and prevention of secondary brain injury. A systematic, multidisciplinary approach to management is paramount to attain favorable outcomes.

Moyamoya disease in children and its anesthetic implications: A review.

Moyamoya disease is a rare, progressive cerebral vasculopathy which most commonly presents in the first and fourth decades of life. The mainstay of treatment is surgical revascularization; without treatment, most patients experience ischemic or hemorrhagic strokes. This report reviews moyamoya disease, its associated conditions, surgical treatment techniques, and anesthetic management of patients with moyamoya disease.

Pharmacokinetics of Cefazolin and Vancomycin in Infants Undergoing Open-Heart Surgery With Cardiopulmonary Bypass.

BACKGROUND: Gram-positive bacteria account for nearly three-quarters of all surgical site infections. Antibiotic prophylaxis against these bacteria with cephalosporins or, in select circumstances, with vancomycin is considered standard of care for prevention of surgical site infections. There is little evidence to describe the optimal dosing regimen for surgical site infection prophylaxis in infants undergoing cardiac surgery, and a great deal of institutional variability exists in dosing prophylactic antibiotics. We designed this study to describe an optimal dose regimen for cephalosporin and vancomycin based on pharmacokinetic evidence for infant open-heart surgery on cardiopulmonary bypass. METHODS: Two separate cohorts of infants undergoing cardiac surgery with cardiopulmonary bypass were evaluated. Plasma concentrations of vancomycin (cohort 1, N = 10) and cefazolin (cohort 2, N = 10) were measured, and mixed-effects pharmacokinetic models were constructed for each drug. Simulations of various dosing regimens were performed to describe an appropriate dosing regimen necessary to maintain antibiotic concentrations above the susceptibility cutoff for staphylococci. RESULTS: Both cefazolin and vancomycin plasma concentration versus time profiles were characterized by a 2-compartment model. Subject weight was a significant covariate for V1 for vancomycin. Subject age was a significant covariate for V1 for cefazolin. Cardiopulmonary bypass did not influence concentration versus time profiles. Simulations demonstrated that a 1-hour vancomycin infusion (15 mg·kg), repeated every 12 hours and a 10-minute infusion of cefazolin (30 mg·kg), repeated every 4 hours maintained plasma concentrations above 4 µg·mL and 16 µg·mL, for vancomycin and cefazolin, respectively. Both concentrations are above the minimum inhibitory concentration 90 for most susceptible staphylococci. CONCLUSIONS: Prophylactic treatment of vancomycin 15 mg·kg infused >1 hour with 12-hour redosing and cefazolin 30 mg·kg infused >10 minutes with 4-hour redosing will maintain serum levels of each antibiotic above the susceptibility cut-offs for susceptible staphylococci in infants undergoing cardiac surgery. Cefazolin levels may be adequate for some, but not all, Gram-negative bacteria. The effect of cardiopulmonary bypass on pharmacokinetics is negligible.

Accuracy of a portable pulse oximeter in monitoring hypoxemic infants with cyanotic heart disease.

OBJECTIVE: Infants with single ventricle physiology have arterial oxygen saturations between 75 and 85%. Home monitoring with daily pulse oximetry is associated with improved interstage survival. They are typically sent home with expensive, bulky, hospital-grade pulse oximeters. This study evaluates the accuracy of both the currently used Masimo LNCS and a relatively inexpensive, portable, and equipped with Bluetooth technology study device, by comparing with the gold standard co-oximeter. DESIGN: Prospective, observational study. SETTING: Single institution, paediatric cardiac critical care unit, and neonatal ICU. INTERVENTIONS: none. PATIENTS: Twenty-four infants under 12 months of age with baseline oxygen saturation less than 90% due to cyanotic CHD. MEASUREMENTS AND RESULTS: Pulse oximetry with WristOx2 3150 with infant sensors 8008 J (study device) and Masimo LCNS saturation sensor connected to a Philips monitor (hospital device) were measured simultaneously and compared to arterial oxy-haemoglobin saturation measured by co-oximetry. Statistical analysis evaluated the performances of each and compared to co-oximetry with Schuirmann's TOST equivalence tests, with equivalence defined as an absolute difference of 5% saturation or less. Neither the study nor the hospital device met the predefined standard for equivalence when compared with co-oximetry. The study device reading was on average 4.0% higher than the co-oximeter, failing to show statistical equivalence (p = 0.16). The hospital device was 7.4% higher than the co-oximeter and also did not meet the predefined standard for equivalence (p = 0.97). CONCLUSION: Both devices tended to overestimate oxygen saturation in this patient population when compared to the gold standard, co-oximetry. The study device is at least as accurate as the hospital device and offers the advantage of being more portable with Bluetooth technology that allows reliable, efficient data transmission. Currently FDA-approved, smaller portable pulse oximeters can be considered for use in home monitoring programmes.

Safety of ferumoxytol in children undergoing cardiac MRI under general anaesthesia.

BACKGROUND: Ferumoxytol, an "off-label" contrast agent, allows for better cardiac MRI quality as compared with gadolinium-based contrast agents. However, hypotension has been reported with the use of ferumoxytol for indications other than cardiac MRI. The purpose of our investigation was to evaluate the safety of ferumoxytol in children undergoing general anaesthesia for cardiac MRI. METHODS: Medical records of children undergoing general anaesthesia for cardiac MRI were reviewed. Baseline demographic and medical characteristics, as well as imaging and anaesthetic duration and technique, were collected. The incidence of hypotension or other adverse events', need for vasoactive support, or airway intervention throughout the anaesthetic, was recorded. RESULTS: A total of 95 patients were identified, 61 received ferumoxytol and 34 received gadolinium. There were no significant differences between groups with respect to age, weight, or baseline blood pressure. The incidence of low blood pressure - systolic or mean - after contrast administration did not differ between groups, and there was no difference in sustained hypotension or use of vasopressors between groups. One patient who received ferumoxytol had possible anaphylaxis. The image acquisition time (45 versus 68 min, p=0.002) and anaesthesia duration (100 versus 132 min, p=0.02) were shorter in the ferumoxytol group. CONCLUSION: Transient low blood pressure was common in children undergoing cardiac MRI with anaesthesia, but the incidence of hypotension did not differ between ferumoxytol and gadolinium groups. The use of ferumoxytol was associated with significantly shorter scan time and anaesthesia duration, as well as a decreased need for airway intervention.

LVOT-VTI is a Useful Indicator of Low Ventricular Function in Young Patients.

Left ventricular outflow tract velocity time integral (LVOT-VTI), a Doppler-derived measure of stroke distance, is used as a surrogate marker of cardiac function in adults. LVOT-VTI is easily obtained, independent of ventricular geometry and wall motion abnormalities. We investigated the relationship between LVOT-VTI and conventional measures of function in young patients by comparing controls to children with dilated cardiomyopathy (DCM). Sixty-two healthy and 52 DCM patients over 1 year were studied retrospectively. The average pulsed (PW) and continuous wave (CW) LVOT-VTIs from apical views were measured from three cycles. Body surface area (BSA) and Ejection fraction (EF) were obtained. We compared LVOT-VTIs between study and control groups and assessed BSA's impact on LVOT-VTI. The entire cohort was classified into three levels of LV function which were compared. We determined LVOT-VTI cutoff values that indicated an EF <50%. The mean PW-LVOT-VTI in the DCM group was significantly lower than that of the normal group (0.15 vs. 0.18 m; p < 0.0012). The mean CW-LVOT-VTI was significantly lower in DCM (0.20 vs. 0.24 m; p < 0.0001). There was no impact of BSA on LVOT-VTI except when comparing BSA and CW-LVOT-VTI in the normal group. There was a positive relationship between LVOT-VTI and EF for PW (Rs = 0.29, p = 0.0022) and CW (Rs = 0.22, p = 0.0364) and a difference in mean LVOT-VTI between EF groups (p < 0.0001). ROC analysis demonstrated that PW-LVOT-VTI <0.17 m (AUC = 0.73; p < 0.0001) and CW-LVOT-VTI <0.22 m (AUC = 0.76; p < 0.0001) was associated with EF <50%. This study indicates that LVOT-VTI can be a useful alternative measure of LV performance in children over 1 year.

Accuracy of Pulse Oximeters Intended for Hypoxemic Pediatric Patients.

OBJECTIVES: Prior studies have shown inaccuracies in pulse oximetry readings at saturations less than 85%; however, no large studies have evaluated new sensors marketed for these low saturations. This study's purpose was to evaluate two sensors with claims of improved accuracy in children with saturations less than 85%. DESIGN: Prospective observational study. SETTING: Single institution; cardiac catheterization laboratory, and operating room. PATIENTS: Fifty patients weighing 3-20 kg with baseline saturations less than 90% undergoing surgical or catheterization procedure. MEASUREMENTS AND MAIN RESULTS: Data collected included demographics, diagnosis, continuous saturations from three different pulse oximeters (Masimo LNCS [Masimo, Irvine, CA], Masimo Blue [Masimo], and Nellcor Max-I [Medtronic, Dublin, Ireland]) and up to four blood samples for co-oximetry as the gold-standard arterial oxygen saturation. Analysis included scatter plots, smoothed regression estimates of mean continuous saturation levels plotted against corresponding arterial oxygen saturation values, and Bland-Altman plots. Bland-Altman analysis indicated increasing levels of bias and variability for decreasing arterial oxygen saturation levels for all three sensors, with a statistically significant increase in mean difference observed for decreasing arterial oxygen saturation level. The Masimo Blue sensor had the lowest mean difference, SD and Bland-Altman limits in patients with saturations less than or equal to 85%. At saturation range of less than or equal to 85% and greater than 75%, 14% of the samples obtained from Masimo Blue, 24% of the readings from the Nellcor, and 31% from the Masimo Standard sensors were greater than or equal to 5% points difference. All three sensors had a further increase in these differences for arterial oxygen saturation values less than 75%. CONCLUSIONS: The Masimo Blue sensor has improved accuracy at saturations 75-85% versus the Nellcor and Masimo Standard sensors. The accuracy of peripheral capillary oxygen saturation of the Masimo Blue sensor was within 5% points of the arterial oxygen saturation the majority of the time. Currently, at saturations less than or equal to 85%, pulse oximetry alone should not be relied on in making clinical decisions.

Hemodynamic Effects of Phenylephrine, Vasopressin, and Epinephrine in Children With Pulmonary Hypertension: A Pilot Study.

OBJECTIVES: During a pulmonary hypertensive crisis, the marked increase in pulmonary vascular resistance can result in acute right ventricular failure and death. Currently, there are no therapeutic guidelines for managing an acute crisis. This pilot study examined the hemodynamic effects of phenylephrine, arginine vasopressin, and epinephrine in pediatric patients with pulmonary hypertension. DESIGN: In this prospective, open-label, nonrandomized pilot study, we enrolled pediatric patients previously diagnosed with pulmonary hypertensive who were scheduled electively for cardiac catheterization. Primary outcome was a change in the ratio of pulmonary-to-systemic vascular resistance. Baseline hemodynamic data were collected before and after the study drug was administered. PATIENTS: Eleven of 15 participants were women, median age was 9.2 years (range, 1.7-14.9 yr), and median weight was 26.8 kg (range, 8.5-55.2 kg). Baseline mean pulmonary artery pressure was 49 ± 19 mm Hg, and mean indexed pulmonary vascular resistance was 10 ± 5.4 Wood units. Etiology of pulmonary hypertensive varied, and all were on systemic pulmonary hypertensive medications. INTERVENTIONS: Patients 1-5 received phenylephrine 1 µg/kg; patients 6-10 received arginine vasopressin 0.03 U/kg; and patients 11-15 received epinephrine 1 µg/kg. Hemodynamics was measured continuously for up to 10 minutes following study drug administration. MEASUREMENTS AND MAIN RESULTS: After study drug administration, the ratio of pulmonary-to-systemic vascular resistance decreased in three of five patients receiving phenylephrine, five of five patients receiving arginine vasopressin, and three of five patients receiving epinephrine. Although all three medications resulted in an increase in aortic pressure, only arginine vasopressin consistently resulted in a decrease in the ratio of systolic pulmonary artery-to-aortic pressure. CONCLUSIONS: This prospective pilot study of phenylephrine, arginine vasopressin, and epinephrine in pediatric patients with pulmonary hypertensive showed an increase in aortic pressure with all drugs although only vasopressin resulted in a consistent decrease in the ratio of pulmonary-to-systemic vascular resistance. Studies with more subjects are warranted to define optimal dosing strategies of these medications in an acute pulmonary hypertensive crisis.

Perioperative management of pediatric en-bloc combined heart-liver transplants: a case series review.

BACKGROUND: Combined heart and liver transplantation (CHLT) in the pediatric population involves a complex group of patients, many of whom have palliated congenital heart disease (CHD) involving single ventricle physiology. OBJECTIVE: The purpose of this study was to describe the perioperative management of pediatric patients undergoing CHLT at a single institution and to identify management strategies that may be used to optimize perioperative care. METHODS: We did a retrospective database review of all patients receiving CHLT at a children's hospital between 2006 and 2014. Information collected included preoperative characteristics, intraoperative management, blood transfusions, and postoperative morbidity and mortality. RESULTS: Five pediatric CHLTs were performed over an 8-year period. All patients had a history of complex CHD with multiple sternotomies, three of whom had failing Fontan physiology. Patient age ranged from 7 to 23 years and weight from 29.5 to 68.5 kg. All CHLTs were performed using an en-bloc technique where both the donor heart and liver were implanted together on cardiopulmonary bypass (CPB). The median operating room time was 14.25 h, median CPB time was 3.58 h, and median donor ischemia time was 4.13 h. Patients separated from CPB on dopamine, epinephrine, and milrinone infusions and two required inhaled nitric oxide. All patients received a massive intraoperative blood transfusion post CPB with amounts ranging from one to three times the patient's estimated blood volume. The patient who required the most transfusions was in decompensated heart and liver failure preoperatively. Four of the five patients received an antifibrinolytic agent as well as a procoagulant (prothrombin complex concentrate or recombinant activated Factor VII) to assist with hemostasis. There were no 30-day thromboembolic events detected. Postoperatively the median length of mechanical ventilation, ICU stay and stay to hospital discharge was 4, 8, and 37 days, respectively. All patients are alive and free from allograft rejection at this time. CONCLUSION: Combined heart and liver transplantation in the pediatric population involves a complex group of patients with unique perioperative challenges. Successful management starts with thorough preoperative planning and communication and involves strategies to deal with massive intraoperative hemorrhage and coagulopathy in addition to protecting and supporting the transplanted heart and liver and meticulous surgical technique. An integrated multidisciplinary team approach is the cornerstone for successful outcomes.

Volatile anesthetic rescue therapy in children with acute asthma: innovative but costly or just costly?.

OBJECTIVES: To describe volatile anesthesia (VA) use for pediatric asthma, including complications and outcomes. DESIGN: Retrospective cohort study. SETTING: Children's hospitals contributing to the Pediatric Health Information System between 2004-2008. PATIENTS: Children 2-18 years old with a primary diagnosis code for asthma supported with mechanical ventilation. INTERVENTION: Those treated with VA were compared to those not treated with VA or extracorporeal membrane oxygenation. Hospital VA use was grouped as none, <5%, 5-10% and >10% among intubated children. MEASUREMENTS AND MAIN RESULTS: One thousand five hundred and fifty-eight patients received mechanical ventilation at 40 hospitals for asthma: 47 (3%) received VA treatment at 11 (28%) hospitals. Those receiving a VA were significantly less likely to receive inhaled b-agonists, ipratropium bromide, and heliox, but more likely to receive neuromuscular blocking agents than patients treated without VA. Length of mechanical ventilation, hospital stay (length of stay [LOS]) and charges were significantly greater for those treated with VA. Aspiration was more common but death and air leak did not differ. Patients at hospitals with VA use >10% were significantly less likely to receive inhaled b agonist, ipratropium bromide, methylxanthines, and heliox, but more likely to receive systemic b agonist, neuromuscular blocking agents compared to those treated at hospitals not using VA. LOS, duration of ventilation, and hospital charges were significantly greater for patients treated at centers with high VA use. CONCLUSIONS: Mortality does not differ between centers that use VA or not. Patients treated at centers with high VA use had significantly increased hospital charges and increased LOS.

Cerebral autoregulation in neonates with a hemodynamically significant patent ductus arteriosus.

OBJECTIVE: Very low birth weight (VLBW) preterm infants are at risk for impaired cerebral autoregulation with pressure passive blood flow. Fluctuations in cerebral perfusion may occur in infants with a hemodynamically significant patent ductus arteriosus (hsPDA), especially during ductal closure. Our goal was to compare cerebral autoregulation using near-infrared spectroscopy in VLBW infants treated for an hsPDA. STUDY DESIGN: This prospective observational study enrolled 28 VLBW infants with an hsPDA diagnosed by echocardiography and 12 control VLBW infants without an hsPDA. Near-infrared spectroscopy cerebral monitoring was applied during conservative treatment, indomethacin treatment, or surgical ligation. A cerebral pressure passivity index (PPI) was calculated, and PPI differences were compared using a mixed-effects regression model. Cranial ultrasound and magnetic resonance imaging data were also assessed. RESULTS: Infants with surgically ligated hsPDAs were more likely to have had a greater PPI within 2 hours following ligation than were those treated with conservative management (P=.04) or indomethacin (P=.0007). These differences resolved by 6 hours after treatment. CONCLUSIONS: Cerebral autoregulation was better preserved after indomethacin treatment of an hsPDA compared with surgical ligation. Infants requiring surgical hsPDA ligation may be at increased risk for cerebral pressure passivity in the 6 hours following surgery.

Perioperative management of the morbidly obese adolescent with heart failure undergoing bariatric surgery.

The incidence and prevalence of adolescent obesity and adolescent heart failure are increasing, and anesthesiologists increasingly will encounter patients with both conditions. A greater understanding of the physiologic challenges of adolescent heart failure as they relate to the perioperative stressors of anesthesia and bariatric surgery is necessary to successfully manage the perioperative risks faced by this growing subpopulation. Here, we present a representative case of a morbidly obese adolescent with heart failure who underwent a laparoscopic bariatric operation and review the limited available literature on perioperative management in this age group. Specifically, we review evidence and offer recommendations related to preoperative evaluation, venous thromboembolism prophylaxis, positioning, induction, airway management, monitoring, anesthetic maintenance, ventilator management, and adverse effects of the pneumoperitoneum, rhabdomyolysis, and postoperative care.

Analgesia, Sedation, and Anesthesia for Neonates With Cardiac Disease.

Analgesia, sedation, and anesthesia are a continuum. Diagnostic and/or therapeutic procedures in newborns often require analgesia, sedation, and/or anesthesia. Newborns, in general, and, particularly, those with heart disease, have an increased risk of serious adverse events, including mortality under anesthesia. In this section, we discuss the assessment and management of pain and discomfort during interventions, review the doses and side effects of commonly used medications, and provide recommendations for their use in newborns with heart disease. For procedures requiring deeper levels of sedation and anesthesia, airway and hemodynamic support might be necessary. Although associations of long-term deleterious neurocognitive effects of anesthetic agents have received considerable attention in both scientific and lay press, causality is not established. Nonetheless, an early multimodal, multidisciplinary approach is beneficial for safe management before, during, and after interventional procedures and surgery to avoid problems of tolerance and delirium, which can contribute to long-term cognitive dysfunction.

Anesthesia-related cardiac arrest in children with heart disease: data from the Pediatric Perioperative Cardiac Arrest (POCA) registry.

BACKGROUND: From 1994 to 2005, the Pediatric Perioperative Cardiac Arrest Registry collected data on 373 anesthesia-related cardiac arrests (CAs) in children, 34% of whom had congenital or acquired heart disease (HD). METHODS: Nearly 80 North American institutions that provide anesthesia for children voluntarily enrolled in the Pediatric Perioperative Cardiac Arrest Registry. A standardized data form for each perioperative CA in children 18 years old or younger was submitted anonymously. We analyzed causes of and outcomes from anesthesia-related CA in children with and without HD. RESULTS: Compared with the 245 children without HD, the 127 children with HD who arrested were sicker (92% vs 62% ASA physical status III-V; P < 0.01) and more likely to arrest from cardiovascular causes (50% vs 38%; P = 0.03), although often the exact cardiovascular cause of arrest could not be determined. Mortality was higher in patients with HD (33%) than those without HD (23%, P = 0.048) but did not differ when adjusted for ASA physical status classification. More than half (54%) of the CA in patients with HD were reported from the general operating room compared with 26% from the cardiac operating room and 17% from the catheterization laboratory. The most common category of HD lesion in patients suffering CA was single ventricle (n = 24). At the time of CA, most patients with congenital HD were either unrepaired (59%) or palliated (26%). Arrests in patients with aortic stenosis and cardiomyopathy were associated with the highest mortality rates (62% and 50%, respectively), although statistical comparison was precluded by small sample size for some HD lesions. CONCLUSIONS: Children with HD were sicker compared with those without HD at the time of anesthesia-related CA and had a higher mortality after arrest. These arrests were reported most frequently from the general operating room and were likely to be from cardiovascular causes. The identification of causes of and factors relating to anesthesia-related CA suggests possible strategies for prevention.

Cerebral oxygen metabolism during total body flow and antegrade cerebral perfusion at deep and moderate hypothermia.

The aim of this study is to evaluate the effect of temperature on cerebral oxygen metabolism at total body flow bypass and antegrade cerebral perfusion (ACP). Neonatal piglets were put on cardiopulmonary bypass (CPB) with the initial flow rate of 200mL/kg/min. After cooling to 18°C (n=6) or 25°C (n=7), flow was reduced to 100mL/kg/min (half-flow, HF) for 15min and ACP was initiated at 40mL/kg/min for 45min. Following rewarming, animals were weaned from bypass and survived for 4h. At baseline, HF, ACP, and 4 h post-CPB, cerebral blood flow (CBF) was measured using fluorescent microspheres. Cerebral oxygen extraction (CEO(2) ) and cerebral metabolic rate of oxygen (CMRO(2) ) were monitored. Regional cranial oxygen saturation (rSO(2) ) was continuously recorded throughout the procedure using near-infrared spectroscopy. At 18°C, CBF trended lower at HF and ACP and matched baseline after CPB. CEO(2) trended lower at HF and ACP, and trended higher after CPB compared with baseline. CMRO(2) at ACP matched that at HF. Cranial rSO(2) was significantly greater at HF and ACP (P<0.001, P<0.001) and matched baseline after CPB. At 25°C, CBF trended lower at HF, rebounded and trended higher at ACP, and matched baseline after CPB. CEO(2) was equal at HF and ACP and trended higher after CPB compared with baseline. CMRO(2) at ACP was greater than that at HF (P=0.001). Cranial rSO(2) was significantly greater at HF (P=0.01), equal at ACP, and lower after CPB (P=0.03). Lactate was significantly higher at all time points (P=0.036, P<0.001, and P<0.001). ACP provided sufficient oxygen to the brain at a total body flow rate of 100mL/kg/min at deep hypothermia. Although ACP provided minimum oxygenation to the brain which met the oxygen requirement, oxygen metabolism was altered during ACP at moderate hypothermia. ACP strategy at moderate hypothermia needs further investigation.