Arch watch: current approaches and opportunities for improvement.

Coarctation of the aorta (CoA) is a ductus arteriosus (DA)-dependent form of congenital heart disease (CHD) characterized by narrowing in the region of the aortic isthmus. CoA is a challenging diagnosis to make prenatally and is the critical cardiac lesion most likely to go undetected on the pulse oximetry-based newborn critical CHD screen. When undetected CoA causes obstruction to blood flow, life-threatening cardiovascular collapse may result, with a high burden of morbidity and mortality. Hemodynamic monitoring practices during DA closure (known as an "arch watch") vary across institutions and existing tools are often insensitive to developing arch obstruction. Novel measures of tissue oxygenation and oxygen deprivation may improve sensitivity and specificity for identifying evolving hemodynamic compromise in the newborn with CoA. We explore the benefits and limitations of existing and new tools to monitor the physiological changes of the aorta as the DA closes in infants at risk of CoA.

Predictors and outcomes of perioperative cardiac arrest in children undergoing noncardiac surgery.

Background: Perioperative cardiac arrest continues to occur. This study aims to identify risk factors for perioperative cardiac arrest in children presenting for noncardiac surgery and characterise its outcomes. Methods: Using the National Surgical Quality Improvement Program (NSQIP) Pediatric Database 2019 and 2020, 261 276 patients were included. Patients ≥18 yr and cardiac surgical procedures were excluded. Exploratory multivariable analysis was performed to identify independent predictors of perioperative cardiac arrest and associated outcomes. Results: The overall rate of cardiac arrest was 0.1%, with an intraoperative rate of 0.05% and 48-h postoperative rate of 0.06%. Significant risk factors for perioperative cardiac arrest included age <12 months (adjusted odds ratios [aOR] 3.07, P<0.001), American Society of Anesthesiology Physical Status classification (ASA-PS 3 aOR=2.57, P<0.001; ASA-PS 4 aOR=5.27, P<0.001; ASA-PS 5 aOR=13.1, P<0.001), admission through the emergency room (aOR 1.7, P=0.003), inpatient (aOR 2.19, P=0.008), major and severe cardiac disease (aOR 1.58, P=0.008), impaired cognitive status (aOR 1.54, P=0.009), and longer anaesthesia duration (aOR 1.1 per 30 min, P<0.001). Perioperative cardiac arrest was significantly associated with longer hospital length of stay, reoperation, differences in discharge destination, and 30-day mortality. In addition, patients experiencing postoperative cardiac arrest had a significantly higher rate of in-hospital and 30-day mortality than those experiencing intraoperative cardiac arrest. Conclusions: The incidence of cardiac arrest in this study is higher than previously reported. This may be related to selection bias and the rigorous data collection required by NSQIP. Lower 30-day mortality after intraoperative cardiac arrest could be related to prompt recognition and rapid initiation of intraoperative resuscitation. Identification of perioperative risk factors for cardiac arrest is crucial to improve the safety and quality of patient care.

Predictors of anesthesia ready time: Analysis and benchmark data.

Objective: Patients undergoing congenital cardiac surgery require induction of anesthesia. Our objective was to identify the median anesthesia ready time and the predictors of this time. Methods: By using the Society of Thoracic Surgeons Congenital Heart Surgery Database, we identified patients who underwent cardiopulmonary bypass procedures from 2017 to 2021. Univariate and multivariable regression modeling to predict the anesthesia ready time was performed using mixed-effects linear regression. Results: After exclusion of outliers, 44,418 cases were analyzed. The median anesthesia ready time was 51 minutes (interquartile range, 38-66). On multivariable analysis, independent predictors of a longer anesthesia ready time included decreasing weight (0.3 min/10 kg, 95% CI, 0.1-0.6; P = .011), prematurity (1.5 minutes, 95% CI, 0.8-2.2; P < .001), and presence of chromosomal abnormality (3.4 minutes, 95% CI, 1.5-5.2; P < .001). An increase in the duration in anesthesia ready time was seen with increasing Society of Thoracic Surgeons-European Association for Cardiothoracic Surgery mortality category with an additional 7.8 minutes (95% CI, 5.2-10.4; P < .001) for a Society of Thoracic Surgeons-European Association for Cardiothoracic Surgery 5 procedure compared with Society of Thoracic Surgeons-European Association for Cardiothoracic Surgery 1. Emergency versus elective case designation was associated with an anesthesia ready time reduction of 3.6 minutes (95% CI, 1.1-6.1; P = .005), and an afternoon case start was associated with an anesthesia ready time reduction of 4.2 minutes (95% CI, 2.8-5.6; P < .001). The presence of an anesthesia trainee increased the anesthesia ready time by 3.8 minutes (95% CI, 2.6-5.0; P < .001). The presence of an airway in situ decreased the anesthesia ready time by 3.6 minutes (95% CI, 1.6-5.5; P < .001), whereas an in situ arterial line decreased the anesthesia ready time by 7.4 minutes (95% CI, 4.6-10.2; P < .001). Placement of a central venous line increased the anesthesia ready time by 8.5 minutes (95% CI, 5.9-11.1; P < .001). Conclusions: The median anesthesia ready time was 51 minutes. For patients with characteristics associated with prolonged anesthesia ready time, consideration should be given to allocation of additional anesthesia staffing to improve efficiency.

Administration of Milrinone Following Tetralogy of Fallot Repair Increases Postoperative Volume Administration Without Improving Cardiac Output.

BACKGROUND: Phosphodiesterase inhibitors are known to relieve symptoms in the setting of heart failure, although their effects in restrictive ventricular physiology have been poorly characterized. We explored the association between the use of milrinone and volume administration during the first 72 hours following surgical repair of tetralogy of Fallot (TOF). METHODS: We reviewed all cases of primary surgical repair of TOF with pulmonary stenosis or atresia at Boston Children's Hospital between 2011 and 2020. To adjust for baseline differences between patients who did and did not receive milrinone, we matched patients with similar propensity scores in a 1:1 ratio (use of milrinone versus not). We then compared the need for volume administration during the first 72 hours postoperatively, vital signs, and measures of cardiac output between the matched cohorts. Additionally, in the group of patients receiving milrinone, linear regression modeling was used to explore the relationship between total dose of milrinone and total volume administration. RESULTS: Among 351 included patients, 134 received perioperative milrinone. A total of 212 patients (106 per group) were matched based on anatomic and surgical risks using a propensity score. After propensity matching, compared with nonmilrinone-treated patients, milrinone-treated patients were given postoperative volume more frequently (66% vs 52%; difference 14% [95% confidence interval, CI, 1%-27%]; P = .036). Milrinone-treated patients had a slower recovery of tachycardia during the first 12 hours (difference in slope 0.30 [95% CI, 0.14-0.47] beats per minute [BPM]/h; P < .001), and the intergroup difference peaked at 12 hours postoperatively (8 [95% CI, 5-12] BPM). Milrinone administration was not associated with improved cardiac output, including arteriovenous oxyhemoglobin saturation difference. In propensity-matched patients receiving milrinone, the total volume administered during the first 72 postoperative hours was significantly associated with the cumulative dose of postoperative milrinone ( r = 0.20; 95% CI, 0.01-0.38; P = .036). Based on the slope of the regression line, for every 1000 µg/kg of milrinone (equivalent to ~0.25 µg/kg/min for 72 hours) administered in the first 72 postoperative hours, an estimated 11.0 (95% CI, 0.6-21.4) mL/kg additional volume was administered. CONCLUSIONS: The use of milrinone within the first 72 hours following TOF repair is associated with more frequent administration of volume, a positive association between a higher total dose of postoperative milrinone and the amount of postoperative volume administered, a higher heart rate, and a lower blood pressure, but is not associated with improved cardiac output.

Patterns in hospital admissions for adults with congenital heart disease for non-cardiac procedures.

OBJECTIVE: Advances in management of congenital heart disease (CHD) have led to an increasing population of adults with CHD, many of whom require non-cardiac procedures. The objectives of this study were to describe the characteristics of these patients, their distribution among different hospital categories and the characteristics determining this distribution, and mortality rates following noncardiac procedures. METHODS: We retrospectively analysed 27 state inpatient databases. Encounters with CHD and non-cardiac procedures were included. The location of care was classified into two categories: hospitals with and without cardiac surgical programmes. Variables included were demographics, comorbidity index, mortality. Multivariable logistic regression was used to explore predictors for care in different locations. RESULTS: The cohort consisted of 12 944 encounters in 1206 hospitals. Most patients were cared for in hospitals with a cardiac surgical programme (78.1%). Patients presenting to hospitals with a cardiac surgical programme presented with higher comorbidity index (6 (IQR: 0-19) vs 2 (IQR: -3-14), p<0.001) than patients presenting to hospitals without a cardiac surgical programme. Mortality was higher in hospitals with cardiac surgical programmes compared with hospitals without cardiac surgical programmes (4.0% vs 2.3%, p<0.001). Factors associated with provision of care at a hospital with a cardiac surgical programme were comorbidity index (>7: OR 2.01 (95% CI 1.83 to 2.21), p<0.001; 2-7: OR 1.59 (95% CI 1.41 to 1.79), p<0.001) and age (18-44 years: OR 1.43 (95% CI 1.26 to 1.62), p<0.001; 45-64 years: OR 1.21 (95% CI 1.08 to 1.34), p<0.001). CONCLUSION: Adults with CHD undergoing non-cardiac procedures are mainly cared for in hospitals with a cardiac surgical programme and have greater comorbidities and higher mortality than those in centres without cardiac surgical programmes. Risk stratification and locoregional accessibility need further assessment to fully understand admission patterns.

Validation of Automated Data Extraction From the Electronic Medical Record to Provide a Pediatric Risk Assessment Score.

BACKGROUND: Although the rate of pediatric postoperative mortality is low, the development and validation of perioperative risk assessment models have allowed for the stratification of those at highest risk, including the Pediatric Risk Assessment (PRAm) score. The clinical application of such tools requires manual data entry, which may be inaccurate or incomplete, compromise efficiency, and increase physicians' clerical obligations. We aimed to create an electronically derived, automated PRAm score and to evaluate its agreement with the original American College of Surgery National Surgical Quality Improvement Program (ACS NSQIP)-derived and validated score. METHODS: We performed a retrospective observational study of children <18 years who underwent noncardiac surgery from 2017 through 2021 at Boston Children's Hospital (BCH). An automated PRAm score was developed via electronic derivation of International Classification of Disease (ICD) -9 and -10 codes. The primary outcome was agreement and correlation among PRAm scores obtained via automation, NSQIP data, and manual physician entry from the same BCH cohort. The secondary outcome was discriminatory ability of the 3 PRAm versions. Fleiss Kappa, Spearman correlation (rho), and intraclass correlation coefficient (ICC) and receiver operating characteristic (ROC) curve analyses with area under the curve (AUC) were applied accordingly. RESULTS: Of the 6014 patients with NSQIP and automated PRAm scores (manual scores: n = 5267), the rate of 30-day mortality was 0.18% (n = 11). Agreement and correlation were greater between the NSQIP and automated scores (rho = 0.78; 95% confidence interval [CI], 0.76-0.79; P <.001; ICC = 0.80; 95% CI, 0.79-0.81; Fleiss kappa = 0.66; 95% CI, 0.65-0.67) versus the NSQIP and manual scores (rho = 0.73; 95% CI, 0.71-0.74; P < .001; ICC = 0.78; 95% CI, 0.77-0.79; Fleiss kappa = 0.56; 95% CI, 0.54-0.57). ROC analysis with AUC showed the manual score to have the greatest discrimination (AUC = 0.976; 95% CI, 0.959,0.993) compared to the NSQIP (AUC = 0.904; 95% CI, 0.792-0.999) and automated (AUC = 0.880; 95% CI, 0.769-0.999) scores. CONCLUSIONS: Development of an electronically derived, automated PRAm score that maintains good discrimination for 30-day mortality in neonates, infants, and children after noncardiac surgery is feasible. The automated PRAm score may reduce the preoperative clerical workload and provide an efficient and accurate means by which to risk stratify neonatal and pediatric surgical patients with the goal of improving clinical outcomes and resource utilization.

Perioperative Considerations for Pediatric Patients With Congenital Heart Disease Presenting for Noncardiac Procedures: A Scientific Statement From the American Heart Association.

Continuous advances in pediatric cardiology, surgery, and critical care have significantly improved survival rates for children and adults with congenital heart disease. Paradoxically, the resulting increase in longevity has expanded the prevalence of both repaired and unrepaired congenital heart disease and has escalated the need for diagnostic and interventional procedures. Because of this expansion in prevalence, anesthesiologists, pediatricians, and other health care professionals increasingly encounter patients with congenital heart disease or other pediatric cardiac diseases who are presenting for surgical treatment of unrelated, noncardiac disease. Patients with congenital heart disease are at high risk for mortality, complications, and reoperation after noncardiac procedures. Rigorous study of risk factors and outcomes has identified subsets of patients with minor, major, and severe congenital heart disease who may have higher-than-baseline risk when undergoing noncardiac procedures, and this has led to the development of risk prediction scores specific to this population. This scientific statement reviews contemporary data on risk from noncardiac procedures, focusing on pediatric patients with congenital heart disease and describing current knowledge on the subject. This scientific statement also addresses preoperative evaluation and testing, perioperative considerations, and postoperative care in this unique patient population and highlights relevant aspects of the pathophysiology of selected conditions that can influence perioperative care and patient management.

A Review of Biventricular Repair for the Congenital Cardiac Anesthesiologist.

The management of children with a borderline ventricle has been debated for many years. The pursuit of a biventricular repair in these children aims to avoid the long-term sequelae of single ventricle palliation. There is a lack of anesthesia literature relating to the care of this complex heterogenous patient population. Anesthesiologists caring for these patients should have an understanding on the many different forms of physiology and the impact on provision of anesthesia and hemodynamic parameters, the goals of biventricular staging and completion as well as the pre-operative, intra-operative, and post-operative considerations relating to this high-risk group of patients.

Anaesthesia for non-cardiac surgery in children and young adults with Fontan physiology.

INTRODUCTION: Patients with Fontan physiology require non-cardiac surgery. Our objectives were to characterise perioperative outcomes of patients with Fontan physiology undergoing non-cardiac surgery and to identify characteristics which predict discharge on the same day. MATERIALS AND METHOD: Children and young adults with Fontan physiology who underwent a non-cardiac surgery or an imaging study under anaesthesia between 2013 and 2019 at a single-centre academic children's hospital were reviewed in a retrospective observational study. Continuous variables were compared using the Wilcoxon rank sum test, and categorical variables were analysed using the Chi-square test or Fisher's exact test. Multivariable logistic regression analysis results are presented by adjusted odds ratios with 95% confidence intervals and p values. RESULTS: 182 patients underwent 344 non-cardiac procedures with anaesthesia. The median age was 11 years (IQR 5.2-18), 56.4% were male. General anaesthesia was administered in 289 (84%). 125 patients (36.3%) were discharged on the same day. On multivariable analysis, independent predictors that reduced the odds of same-day discharge included the chronic condition index (OR 0.91 per additional chronic condition, 95% CI 0.76-0.98, p = 0.022), undergoing a major surgical procedure (OR 0.17, 95% CI 0.05-0.64, p = 0.009), the use of intraoperative inotropes (OR 0.48, 95% CI 0.25-0.94, p = 0.031), and preoperative admission (OR = 0.24, 95% CI: 0.1-0.57, p = 0.001). DISCUSSION: In a contemporary cohort of paediatric and young adults with Fontan physiology, 36.3% were able to be discharged on the same day of their non-cardiac procedure. Well selected patients with Fontan physiology can undergo anaesthesia without complications and be discharged same day.

Patients With Congenital Heart Disease Undergoing Noncardiac Procedures at Hospitals With and Without a Cardiac Surgical Program.

Background The type and location of hospitals where patients with congenital heart disease (CHD) undergo noncardiac procedures have not been investigated. This study aimed to describe (1) the characteristics of these patients, (2) the distribution of procedures among hospitals with and without a cardiac surgical program and travel distances, (3) the characteristics determining the distribution, and (4) mortality rates. Methods and Results This is a retrospective cohort analysis of inpatient data from the Center for Healthcare Information and Analysis of the Commonwealth of Massachusetts, Texas Healthcare Information Collection, and Health Care Cost and Utilization Project State Inpatient Database. Children <18 years old with CHD who underwent noncardiac procedures were included. Distances were calculated using the Haversine formula. Logistic regression was performed to evaluate the odds of a procedure at a hospital with a cardiac program. There were 7435 encounters at 235 hospitals analyzed. Most procedures (87.8%) occurred at hospitals with a cardiac program. Patients at a hospital without a cardiac program had simple CHD (72.4%) with <1% with single ventricle disease. At hospitals with a cardiac program, 56.8% had simple CHD, 35.4% complex CHD, and 7.8% single ventricle disease. The median distance traveled was 25.2 miles (interquartile range, 10.3-73.8 miles) to a hospital with a cardiac program and 14.6 miles (interquartile range, 6.2-37.4 miles) to a hospital without a cardiac program (P<0.001). Single ventricle disease (adjusted odds ratio [aOR], 16.25 [95% CI, 7.22-36.61]) and ≥6 chronic conditions (aOR, 1.81 [95% CI, 1.57-2.09]) were associated with performance at a hospital with a cardiac program. Mortality rate was 3.8%. Conclusions Patients with CHD are more likely to travel to a hospital with a cardiac program for noncardiac procedures than to a hospital without; especially patients with single ventricle disease, other complex CHD, and with ≥6 chronic conditions.

Biventricular repair as an alternative to single-ventricle palliation in a child with hypoplastic left heart structures: What the anesthesiologist should know.

Enhanced techniques for single-ventricle palliation (SVP), in which the Fontan procedure is the final phase, have improved the survival and quality of life in patients not eligible for biventricular repair (BiVR). However, Fontan physiology also is associated with predictable long-term consequences that ultimately affect quality of life and freedom from adverse events. Given this harsh reality, the advances in ventricular rehabilitation strategies and the conversion from SVP increasingly are being used to achieve biventricular circulation in patients with left-heart hypoplasia who previously were considered to be marginal or unacceptable candidates for BiVR. The techniques for ventricular recruitment include restriction of the atrial septal defect (ASD), atrioventricular valve repair, repair of left ventricular outflow obstruction, endocardial fibroelastosis resection, an augmented pulmonary blood flow, and catheter-based interventions. In addition, reverse double-switch surgery has been used as an option for patients with a left ventricle of insufficient size and function to support the systemic circulation, who would otherwise require a Fontan surgery. Despite improved management and surgical technique, the outcomes after biventricular staging repair and conversion remain variable, and the complications ultimately may exclude patients from future single-ventricle palliation or transplant. The anesthesiologist should have a basic understanding of the anatomy and physiology of this growing patient population in order to develop adequate perioperative management options.

Sudden cardiac death in congenital heart disease.

Sudden cardiac death (SCD) accounts for up to 25% of deaths in patients with congenital heart disease (CHD). To date, research has largely been driven by observational studies and real-world experience. Drawbacks include varying definitions, incomplete taxonomy that considers SCD as a unitary diagnosis as opposed to a terminal event with diverse causes, inconsistent outcome ascertainment, and limited data granularity. Notwithstanding these constraints, identified higher-risk substrates include tetralogy of Fallot, transposition of the great arteries, cyanotic heart disease, Ebstein anomaly, and Fontan circulation. Without autopsies, it is often impossible to distinguish SCD from non-cardiac sudden deaths. Asystole and pulseless electrical activity account for a high proportion of SCDs, particularly in patients with heart failure. High-quality cardiopulmonary resuscitation is essential to improve outcomes. Pulmonary hypertension and CHD complexity are associated with lower likelihood of successful resuscitation. Risk stratification for primary prevention implantable cardioverter-defibrillators (ICDs) should consider the probability of SCD due to a shockable rhythm, competing causes of mortality, complications of ICD therapy, and associated costs. Risk scores to better estimate probabilities of SCD and CHD-specific guidelines and consensus-based recommendations have been proposed. The subcutaneous ICD has emerged as an attractive alternative to transvenous systems in those with vascular access limitations, prior device infections, intra-cardiac shunts, or a Fontan circulation. Further improving SCD-related outcomes will require a multidimensional approach to research that addresses disease processes and triggers, taxonomy to better reflect underlying pathophysiology, high-risk features, early warning signs, access to high-quality cardiopulmonary resuscitation and specialized care, and preventive therapies tailored to underlying mechanisms.

Anesthesia in Children With Pulmonary Hypertension: Clinically Significant Serious Adverse Events Associated With Cardiac Catheterization and Noncardiac Procedures.

OBJECTIVES: To determine the incidence of clinically significant serious adverse events in a contemporary population of pediatric patients with pulmonary hypertension who require anesthesia and identify factors associated with adverse outcomes. DESIGN: A retrospective, cross-sectional study. SETTING: A single-center quaternary-care freestanding children's hospital in the northeastern United States. PARTICIPANTS: Pediatric patients with pulmonary hypertension based on hemodynamic criteria on cardiac catheterization during a 3-year period from 2015 to 2018. INTERVENTIONS: Anesthesia care for cardiac catheterization, noncardiac surgery, and diagnostic imaging. MEASUREMENTS AND MAIN RESULTS: Two hundred forty-nine children underwent 862 procedures, 592 for cardiac catheterization and 278 for noncardiac surgery and diagnostic imaging. The median age was 1.6 years, and the weight was 9.5 lbs. On index catheterization, median pulmonary artery pressure was 36 mmHg, and the pulmonary vascular resistance was 5.1 indexed Wood units. Ten percent of anesthetics were performed with a natural airway, and 80% used volatile anesthetics. Serious adverse events occurred in 26% of procedures (confidence interval [CI], 22%-30%). The rate of periprocedural cardiac arrest was 8 per 1,000 anesthetic administrations. In multivariate analysis, younger age (adjusted odds ratio [aOR], 1.4 per year; CI, 1.1-1.9; p = 0.01), location in the catheterization laboratory (aOR, 5.1; CI, 1.7-16; p = 0.004), and longer procedure duration (aOR, 1.3 per 30 minutes; CI, 1.1-1.4; p = 0.001) were associated with serious adverse events. Patients with a tracheostomy in place were less likely to experience an adverse event (aOR, 0.1; CI, 0.04-0.5; p = 0.001). The primary anesthetic technique was not associated with adverse events. Interventional cardiac catheterization was associated with an increased incidence of adverse events compared with diagnostic catheterization (42% v 21%; OR, 2.23; CI, 1.5-3.3; p < 0.001). CONCLUSIONS: Serious adverse events were common in this cohort. Careful planning to minimize anesthesia time in young children with pulmonary hypertension should be undertaken, and these factors considered in designing risk mitigation strategies.

The Practice of Pediatric Cardiac Anesthesiology in the United States.

BACKGROUND: With advances in surgical and catheter-based interventions and technologies in patients with congenital heart disease (CHD), the practice of pediatric cardiac anesthesiology has evolved in parallel with pediatric cardiac surgery and pediatric cardiology as a distinct subspecialty over the past 80 years. To date, there has not been an analysis of the distribution of pediatric cardiac anesthesiologists relative to cardiac and noncardiac procedures in the pediatric population. The primary aim is to report the results of a survey and its subsequent analysis to describe the distribution of pediatric cardiac anesthesiologists relative to pediatric cardiac procedures that include surgical interventions, cardiac catheterization procedures, imaging studies (echocardiography, magnetic resonance, computed tomography, positron emission tomography), and noncardiac procedures. METHODS: A survey developed in Research Electronic Data Capture (REDcap) was sent to the identifiable division chiefs/cardiac directors of 113 pediatric cardiac anesthesia programs in the United States. Data regarding cardiac surgical patients and procedures were collected from the Society of Thoracic Surgeons Congenital Heart Surgery Database (STS-CHD). RESULTS: This analysis reveals that only 38% (117 of 307) of pediatric cardiac anesthesiologists caring for patients with CHD pursued additional training in pediatric cardiac anesthesiology, while 44% (136 of 307) have gained experience during their clinical practice. Other providers have pursued different training pathways such as adult cardiac anesthesiology or pediatric critical care. Based on this survey, pediatric cardiac anesthesiologists devote 35% (interquartile range [IQR], 20%-50%) of clinical time to the care of patients in the cardiac operating room, 25% (20%-35%) of time to the care of patients in the cardiac catheterization laboratory, 10% (5%-10%) to patient care in imaging locations, and 15% covering general pediatric, adult, or cardiac patients undergoing noncardiac procedures. Attempts to actively recruit pediatric cardiac anesthesiologists were reported by 49.2% (29 of 59) of the institutions surveyed. Impending retirement of staff was anticipated in 17% (10 of 59) of the institutions, while loss of staff to relocation was anticipated in 3.4% (2 of 59) of institutions. Thirty-seven percent of institutions reported that they anticipated no immediate changes in current staffing levels. CONCLUSIONS: The majority of currently practicing pediatric cardiac anesthesiologists have not completed a fellowship training in the subspecialty. There is, and will continue to be, a need for subspecialty training to meet increasing demand for services especially with increase survival of this patient population and to replace retiring members of the workforce.