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An anesthesiologist for all pediatric cardiac catheterizations: luxury or necessity?
VOL 17, NO 6
DECEMBER 2003
EDITORIAL An Anesthesiologist for All Pediatric Cardiac Catheterizations: Luxury or Necessity?
P
EDIATRIC CARDIAC CATHETERIZATION was first described in the 1930s by Castellanos et al,1 and at that time was purely a diagnostic tool. By the 1950s, sedation techniques for pediatric cardiac catheterization were described in the anesthesia literature, using agents such as intramuscular meperidine, promethazine, and chlorpromazine.2 The first interventional catheterization procedure to be widely used was the balloon atrial septostomy for neonates with transposition of the great arteries, reported by Rashkind and Miller in 1968.3 In the 1980s, as echocardiography became accepted as a noninvasive diagnostic imaging modality, cardiac catheterization for anatomic diagnosis became less widely used. By the mid-1990s several important developments further changed the scope and practice of pediatric cardiac catheterization: interventional cardiology became firmly established,4 magnetic resonance imaging was added to echocardiography as a noninvasive diagnostic imaging modality,5 and the trend toward surgery in early infancy increased dramatically.6 These developments altered the profile of the average patient in the pediatric cardiac catheterization laboratory toward a smaller, more ill patient with complex anatomy, often requiring intervention for preoperative stabilization or to correct residual postoperative defects.7 The addition of lengthy electrophysiologic procedures such as radiofrequency ablation and transvenous pacemaker and automatic internal cardioverter-defibrillator placements in infants and smaller children also increased.8 The services of a skilled anesthesiologist have become more desirable in these settings, and in many centers, where formerly there was little or no involvement by anesthesiologists, there is now an increasing need for these services. At Texas Children’s Hospital, for instance, in the 12 months from September 2002 to August 2003, 970 catheterization procedures were performed, and 74% of these used the services of an anesthesiologist. Three hundred forty-five procedures were interventional catheterizations, including 102 atrial septal defect
closures, 47 patent ductus arteriosus occlusions, and 60 balloon angioplasties for aortic or pulmonary valve stenosis or coarctations of the aorta. Interventional procedures require an immobile patient and commonly require treatment of hemodynamic instability such as hypotension, sudden hypertension, and tachycardia from the pain of balloon angioplasty, arrhythmia, heart block, blood loss, and pulmonary hypertension.9 Diagnostic procedures are most often reserved for patients with complex single-ventricle anatomy, in which surgical approach and timing are determined from the information gained; therefore, valid hemodynamic information is critical. These procedures require stable hemodynamics, and measurements are usually acquired with the patient breathing 21% oxygen with normal pH and partial pressure of carbon dioxide values to acquire valid data. These conditions are obviously significantly influenced by choice of anesthetic agent and airway management (eg, spontaneous ventilation is accompanied by a risk of airway obstruction and hypoventilation) versus endotracheal intubation and positive-pressure ventilation that affects venous return and hemodynamics. It has never been more important to provide a skillful anesthetic tailored to the patient’s specific anatomy and pathophysiology, with the requirements of the catheterization procedure in mind. Additional demands include efficiency of service, a pleasant experience for the patient and family, and rapid recovery without nausea or undue dysphoria. All of these issues fuel the search for new information and techniques for providing anesthesia in the pediatric cardiac catheterization laboratory. In this issue, 2 studies of propofol and ketamine for pediatric cardiac catheterization are published, adding im-
© 2003 Elsevier Inc. All rights reserved. 1053-0770/03/1706-0001$30.00/0 doi:10.1053/j.jvca.2003.09.003
Journal of Cardiothoracic and Vascular Anesthesia, Vol 17, No 6 (December), 2003: pp 683-685
683
684
portant new information about these agents with long histories of use in the catheterization laboratory. Ketamine has been used for more than 3 decades to provide sedation and analgesia for pediatric cardiac catheterization.10 A stable respiratory and hemodynamic state is usually produced, often increasing heart rate and mean arterial pressure (MAP) and possibly increasing pulmonary vascular resistance (PVR). However, these effects may significantly alter the hemodynamic data acquired, and coupled with its propensity for dysphoria and prolonged awakening, ketamine is considered less desirable by many anesthesiologists. Propofol was introduced in the United States in 1990 and became widely used for many nonoperating room pediatric anesthetics including cardiac catheterization. Advantages include a rapid, pleasant awakening and antiemetic effects, but disadvantages include significant decreases in MAP and systemic vascular resistance (SVR), with little change in PVR, decreasing pulmonary-to-systemic blood flow ratio (Qp:Qs), and increased right-to-left intracardiac shunting,11 which will increase cyanosis in some patients. Despite widespread use of both of these agents, no prospective, randomized, controlled study comparing the 2 has been published. Oklu et al12 compared ketamine with propofol in a prospective, randomized controlled study of 41 patients spontaneously breathing room air for diagnostic catheterization, with full hemodynamic cardiac catheterization measurements made before and after infusions of both agents. The patients were divided into 3 groups: (1) no intracardiac shunting (eg, isolated pulmonic stenosis), (2) left-to–right intracardiac shunting (eg, ventricular septal defect with pulmonary overcirculation), and (3) right-to-left intracardiac shunting (eg, cyanotic tetralogy of Fallot). At doses of 50 to 75 g/kg/min of ketamine and 100 to 200 g/kg/min of propofol, they showed clinically important differences between the 2 agents in their population. In groups 2 and 3 (patients with intracardiac shunting), propofol significantly decreased SVR and increased systemic blood flow (Qs) while not affecting PVR or pulmonary blood flow (Qp). The net result was a decreased Qp:Qs, thereby increasing cyanosis in patients with right-to-left intracardiac shunt. Ketamine increased systemic MAP in all groups but did not affect heart rate, mean pulmonary artery pressure, PVR, SVR, or Qp:Qs. Unfortunately, recovery times are not reported. Nevertheless, this comparison gives the anesthesiologist more information on which to base a decision about choice of anesthetic, particularly in cyanotic patients. Kogan et al13 describe a novel mixture of ketamine and propofol for diagnostic and interventional catheterization in 45 children, again spontaneously breathing room air. In the same syringe, propofol (4 mg/mL) and ketamine (2 mg/mL) were infused in a constant ratio (with additional small boluses given as needed), with a mean ketamine dose of 26 g/kg/min and propofol dose of 68 g/kg/min required for successful sedation for completion of the procedures. Hemodynamic and respiratory changes from baseline were minimal, with only 9% of patients experiencing heart rate changes of more than 20% from baseline, 11% MAP changes more than 20%, and 6.7% a decrease in arterial oxygen saturation more than 5% from baseline. Procedures
ANDROPOULOS AND STAYER
were successfully completed in all patients, and the mean time to meeting recovery room discharge criteria was 51 minutes. This combination of agents would appear to preserve the advantages and avoid most of the disadvantages of both agents by allowing lower doses of each agent and offsetting the undesirable hemodynamic effects of both. The increased heart rate and MAP often seen with ketamine are offset by the effects of propofol to lower MAP, and the sometimes prolonged awakening with ketamine is avoided. Unfortunately, the authors did not perform a hemodynamic study before and after infusion of these agents. However, this study again gives new information for the anesthesiologist and provides another viable option to meet the sedation, ventilation, and hemodynamic requirements to successfully complete cardiac catheterization procedures. More well-designed, prospective, randomized, controlled studies, with complete hemodynamic assessments, are needed to evaluate existing and novel anesthetic regimens for cardiac catheterization. The need for skilled anesthesiologists in the pediatric cardiac catheterization laboratory will increase with new innovations in catheter therapy. Despite recent advocacy of the use of ketamine and midazolam in combination for interventional catheterizations administered by the cardiologist without the presence of an anesthesiologist,14 complexity of the patients and interventions, and the risk for instability and complications because of the procedure itself, or the sedation or anesthesia, mandate the presence of a skilled practitioner in sedation, airway management, and resuscitation. New procedures such as the combination of interventional procedures with magnetic resonance imaging15 to immediately assess results in 3 dimensions will tax the abilities of the anesthesiologist, as will combined catheter and surgical interventions,16 often taking place in the cardiac catheterization laboratory. The potential use of catheter interventions in the fetus for lesions such as critical aortic stenosis is developing17; these procedures may actually require the services of 2 anesthesiologists: 1 for the mother and 1 for the fetus. The increasing number of adult patients with congenital heart disease often require invasive catheterization services, as well as electrophysiology and pacemaker procedures.18 Thus, the scope of practice of the cardiac anesthesiologist is expanding from the confines of the operating room to include catheterization patients at the extremes of the age and disease spectrum. Anesthesiologists will do well to provide for the needs of all of these patients, allowing the cardiologists to fully concentrate on their demanding technical tasks, and thus improving the experience and outcome of these often complex and difficult patients.
Dean B. Andropoulos, MD Stephen A. Stayer, MD Division of Pediatric Cardiovascular Anesthesiology Texas Children’s Hospital Departments of Anesthesiology and Pediatrics Baylor College of Medicine Houston, TX
EDITORIAL
685
REFERENCES 1. Castellanos AR, Pereiras R, Varcia A. Angiocardiography in the child. Proceedings of the 7th Congress of the Pan American Medical Association, Havana, Cuba, 1939, pp 75-82, 109-113 2. Smith C: Sedation of children for cardiac catheterization with an atretic mixture. Can Anaesth Soc J 5:35-40, 1958 3. Rashkind WJ, Miller WW: Transposition of the great arteries. Results of palliation by balloon atrioseptostomy in thirty-one infants. Circulation 38:453-462, 1968 4. Grifka RG: Transcatheter intervention for the treatment of congenital cardiac defects. Texas Heart Inst J 24:293-300, 1997 5. Sahn DJ, Vick GW 3rd: Review of new techniques in echocardiography and magnetic resonance imaging as applied to patients with congenital heart disease. Heart 86:II41-53, 2001 (Suppl 2) 6. Castaneda AR, Mayer Jonas RA, et al: The neonate with critical congenital heart disease: Repair—A surgical challenge. J Thorac Cardiovasc Surg 98:869-875, 1989 7. Shim D, Lloyd TR, Crowley DC, et al: Neonatal cardiac catheterization: A 10-year transition from diagnosis to therapy. Pediatr Cardiol 20:131-133, 1999 8. Erickson CC, Walsh EP, Triedman JK, et al: Efficacy and safety of radiofrequency ablation in infants and young children ⬍ 18 months of age. Am J Cardiol 74:944-947, 1994 9. Vitiello R, McCrindle BW, Nykanen D, et al: Complications associated with pediatric cardiac catheterization. J Am Coll Cardiol 32:1433-1440, 1998 10. Faithfull NS, Haider R: Ketamine for cardiac catheterization: An evaluation of its use in children. Anaesthesia 26:318-323, 1971
11. Williams GD, Jones TK, Hanson KA, et al: The hemodynamic effects of propofol in children with congenital heart disease. Anesth Analg 89:1411-1416, 1999 ¨ klu¨ E, Buluctu FS, Yalc¸ ın Y, et al: Which anesthetic agent 12. O alters the hemodynamic status during pediatric cardiac catheterization? Comparison of propofol versus ketamine. J Cardiothor Vasc Anesth 17:686-690, 2003 13. Kogan A, Efrat R, Katz J, et al. Propofol-ketamine mixture for anesthesia in pediatric patients undergoing cardiac catheterization. J Cardiothor Vasc Anesth 17:691-693, 2003 14. Jobier A, Galal MO, Bulbul ZR, et al: Use of low-dose ketamine and/or midazolam for pediatric cardiac catheterization: Is an anesthesiologist needed? Pediatr Cardiol 24:236-243, 2003 15. Geva T, Griel GF, Marshall AC, et al: Gadolinium-enhanced 3-dimensional magnetic resonance angiography of pulmonary blood supply in patients with complex pulmonary stenosis or atresia: Comparison with x-ray angiography. Circulation 106:473-478, 2002 16. Trivedi KR, Asakie A, Benson LN: Collaborative interventional and surgical strategies in the management of congenital heart lesions. Semin Thorac Cardiovasc Surg Pediatr Card Surg Ann 4:185-207, 2001 17. Tworetsky W, Jennings RW, Wilkins-Haug LE, et al: Balloon dilation of severe aortic stenosis in the fetus: Technical advances. J Am Coll Cardiol 41:496A, 2003 (abstr) 18. Hornung TS, Benson LN, McLaughlin PR: Catheter interventions in adult patients with congenital heart disease. Curr Cardiol Rep 4:54-56, 2002
DECEMBER 2003
EDITORIAL An Anesthesiologist for All Pediatric Cardiac Catheterizations: Luxury or Necessity?
P
EDIATRIC CARDIAC CATHETERIZATION was first described in the 1930s by Castellanos et al,1 and at that time was purely a diagnostic tool. By the 1950s, sedation techniques for pediatric cardiac catheterization were described in the anesthesia literature, using agents such as intramuscular meperidine, promethazine, and chlorpromazine.2 The first interventional catheterization procedure to be widely used was the balloon atrial septostomy for neonates with transposition of the great arteries, reported by Rashkind and Miller in 1968.3 In the 1980s, as echocardiography became accepted as a noninvasive diagnostic imaging modality, cardiac catheterization for anatomic diagnosis became less widely used. By the mid-1990s several important developments further changed the scope and practice of pediatric cardiac catheterization: interventional cardiology became firmly established,4 magnetic resonance imaging was added to echocardiography as a noninvasive diagnostic imaging modality,5 and the trend toward surgery in early infancy increased dramatically.6 These developments altered the profile of the average patient in the pediatric cardiac catheterization laboratory toward a smaller, more ill patient with complex anatomy, often requiring intervention for preoperative stabilization or to correct residual postoperative defects.7 The addition of lengthy electrophysiologic procedures such as radiofrequency ablation and transvenous pacemaker and automatic internal cardioverter-defibrillator placements in infants and smaller children also increased.8 The services of a skilled anesthesiologist have become more desirable in these settings, and in many centers, where formerly there was little or no involvement by anesthesiologists, there is now an increasing need for these services. At Texas Children’s Hospital, for instance, in the 12 months from September 2002 to August 2003, 970 catheterization procedures were performed, and 74% of these used the services of an anesthesiologist. Three hundred forty-five procedures were interventional catheterizations, including 102 atrial septal defect
closures, 47 patent ductus arteriosus occlusions, and 60 balloon angioplasties for aortic or pulmonary valve stenosis or coarctations of the aorta. Interventional procedures require an immobile patient and commonly require treatment of hemodynamic instability such as hypotension, sudden hypertension, and tachycardia from the pain of balloon angioplasty, arrhythmia, heart block, blood loss, and pulmonary hypertension.9 Diagnostic procedures are most often reserved for patients with complex single-ventricle anatomy, in which surgical approach and timing are determined from the information gained; therefore, valid hemodynamic information is critical. These procedures require stable hemodynamics, and measurements are usually acquired with the patient breathing 21% oxygen with normal pH and partial pressure of carbon dioxide values to acquire valid data. These conditions are obviously significantly influenced by choice of anesthetic agent and airway management (eg, spontaneous ventilation is accompanied by a risk of airway obstruction and hypoventilation) versus endotracheal intubation and positive-pressure ventilation that affects venous return and hemodynamics. It has never been more important to provide a skillful anesthetic tailored to the patient’s specific anatomy and pathophysiology, with the requirements of the catheterization procedure in mind. Additional demands include efficiency of service, a pleasant experience for the patient and family, and rapid recovery without nausea or undue dysphoria. All of these issues fuel the search for new information and techniques for providing anesthesia in the pediatric cardiac catheterization laboratory. In this issue, 2 studies of propofol and ketamine for pediatric cardiac catheterization are published, adding im-
© 2003 Elsevier Inc. All rights reserved. 1053-0770/03/1706-0001$30.00/0 doi:10.1053/j.jvca.2003.09.003
Journal of Cardiothoracic and Vascular Anesthesia, Vol 17, No 6 (December), 2003: pp 683-685
683
684
portant new information about these agents with long histories of use in the catheterization laboratory. Ketamine has been used for more than 3 decades to provide sedation and analgesia for pediatric cardiac catheterization.10 A stable respiratory and hemodynamic state is usually produced, often increasing heart rate and mean arterial pressure (MAP) and possibly increasing pulmonary vascular resistance (PVR). However, these effects may significantly alter the hemodynamic data acquired, and coupled with its propensity for dysphoria and prolonged awakening, ketamine is considered less desirable by many anesthesiologists. Propofol was introduced in the United States in 1990 and became widely used for many nonoperating room pediatric anesthetics including cardiac catheterization. Advantages include a rapid, pleasant awakening and antiemetic effects, but disadvantages include significant decreases in MAP and systemic vascular resistance (SVR), with little change in PVR, decreasing pulmonary-to-systemic blood flow ratio (Qp:Qs), and increased right-to-left intracardiac shunting,11 which will increase cyanosis in some patients. Despite widespread use of both of these agents, no prospective, randomized, controlled study comparing the 2 has been published. Oklu et al12 compared ketamine with propofol in a prospective, randomized controlled study of 41 patients spontaneously breathing room air for diagnostic catheterization, with full hemodynamic cardiac catheterization measurements made before and after infusions of both agents. The patients were divided into 3 groups: (1) no intracardiac shunting (eg, isolated pulmonic stenosis), (2) left-to–right intracardiac shunting (eg, ventricular septal defect with pulmonary overcirculation), and (3) right-to-left intracardiac shunting (eg, cyanotic tetralogy of Fallot). At doses of 50 to 75 g/kg/min of ketamine and 100 to 200 g/kg/min of propofol, they showed clinically important differences between the 2 agents in their population. In groups 2 and 3 (patients with intracardiac shunting), propofol significantly decreased SVR and increased systemic blood flow (Qs) while not affecting PVR or pulmonary blood flow (Qp). The net result was a decreased Qp:Qs, thereby increasing cyanosis in patients with right-to-left intracardiac shunt. Ketamine increased systemic MAP in all groups but did not affect heart rate, mean pulmonary artery pressure, PVR, SVR, or Qp:Qs. Unfortunately, recovery times are not reported. Nevertheless, this comparison gives the anesthesiologist more information on which to base a decision about choice of anesthetic, particularly in cyanotic patients. Kogan et al13 describe a novel mixture of ketamine and propofol for diagnostic and interventional catheterization in 45 children, again spontaneously breathing room air. In the same syringe, propofol (4 mg/mL) and ketamine (2 mg/mL) were infused in a constant ratio (with additional small boluses given as needed), with a mean ketamine dose of 26 g/kg/min and propofol dose of 68 g/kg/min required for successful sedation for completion of the procedures. Hemodynamic and respiratory changes from baseline were minimal, with only 9% of patients experiencing heart rate changes of more than 20% from baseline, 11% MAP changes more than 20%, and 6.7% a decrease in arterial oxygen saturation more than 5% from baseline. Procedures
ANDROPOULOS AND STAYER
were successfully completed in all patients, and the mean time to meeting recovery room discharge criteria was 51 minutes. This combination of agents would appear to preserve the advantages and avoid most of the disadvantages of both agents by allowing lower doses of each agent and offsetting the undesirable hemodynamic effects of both. The increased heart rate and MAP often seen with ketamine are offset by the effects of propofol to lower MAP, and the sometimes prolonged awakening with ketamine is avoided. Unfortunately, the authors did not perform a hemodynamic study before and after infusion of these agents. However, this study again gives new information for the anesthesiologist and provides another viable option to meet the sedation, ventilation, and hemodynamic requirements to successfully complete cardiac catheterization procedures. More well-designed, prospective, randomized, controlled studies, with complete hemodynamic assessments, are needed to evaluate existing and novel anesthetic regimens for cardiac catheterization. The need for skilled anesthesiologists in the pediatric cardiac catheterization laboratory will increase with new innovations in catheter therapy. Despite recent advocacy of the use of ketamine and midazolam in combination for interventional catheterizations administered by the cardiologist without the presence of an anesthesiologist,14 complexity of the patients and interventions, and the risk for instability and complications because of the procedure itself, or the sedation or anesthesia, mandate the presence of a skilled practitioner in sedation, airway management, and resuscitation. New procedures such as the combination of interventional procedures with magnetic resonance imaging15 to immediately assess results in 3 dimensions will tax the abilities of the anesthesiologist, as will combined catheter and surgical interventions,16 often taking place in the cardiac catheterization laboratory. The potential use of catheter interventions in the fetus for lesions such as critical aortic stenosis is developing17; these procedures may actually require the services of 2 anesthesiologists: 1 for the mother and 1 for the fetus. The increasing number of adult patients with congenital heart disease often require invasive catheterization services, as well as electrophysiology and pacemaker procedures.18 Thus, the scope of practice of the cardiac anesthesiologist is expanding from the confines of the operating room to include catheterization patients at the extremes of the age and disease spectrum. Anesthesiologists will do well to provide for the needs of all of these patients, allowing the cardiologists to fully concentrate on their demanding technical tasks, and thus improving the experience and outcome of these often complex and difficult patients.
Dean B. Andropoulos, MD Stephen A. Stayer, MD Division of Pediatric Cardiovascular Anesthesiology Texas Children’s Hospital Departments of Anesthesiology and Pediatrics Baylor College of Medicine Houston, TX
EDITORIAL
685
REFERENCES 1. Castellanos AR, Pereiras R, Varcia A. Angiocardiography in the child. Proceedings of the 7th Congress of the Pan American Medical Association, Havana, Cuba, 1939, pp 75-82, 109-113 2. Smith C: Sedation of children for cardiac catheterization with an atretic mixture. Can Anaesth Soc J 5:35-40, 1958 3. Rashkind WJ, Miller WW: Transposition of the great arteries. Results of palliation by balloon atrioseptostomy in thirty-one infants. Circulation 38:453-462, 1968 4. Grifka RG: Transcatheter intervention for the treatment of congenital cardiac defects. Texas Heart Inst J 24:293-300, 1997 5. Sahn DJ, Vick GW 3rd: Review of new techniques in echocardiography and magnetic resonance imaging as applied to patients with congenital heart disease. Heart 86:II41-53, 2001 (Suppl 2) 6. Castaneda AR, Mayer Jonas RA, et al: The neonate with critical congenital heart disease: Repair—A surgical challenge. J Thorac Cardiovasc Surg 98:869-875, 1989 7. Shim D, Lloyd TR, Crowley DC, et al: Neonatal cardiac catheterization: A 10-year transition from diagnosis to therapy. Pediatr Cardiol 20:131-133, 1999 8. Erickson CC, Walsh EP, Triedman JK, et al: Efficacy and safety of radiofrequency ablation in infants and young children ⬍ 18 months of age. Am J Cardiol 74:944-947, 1994 9. Vitiello R, McCrindle BW, Nykanen D, et al: Complications associated with pediatric cardiac catheterization. J Am Coll Cardiol 32:1433-1440, 1998 10. Faithfull NS, Haider R: Ketamine for cardiac catheterization: An evaluation of its use in children. Anaesthesia 26:318-323, 1971
11. Williams GD, Jones TK, Hanson KA, et al: The hemodynamic effects of propofol in children with congenital heart disease. Anesth Analg 89:1411-1416, 1999 ¨ klu¨ E, Buluctu FS, Yalc¸ ın Y, et al: Which anesthetic agent 12. O alters the hemodynamic status during pediatric cardiac catheterization? Comparison of propofol versus ketamine. J Cardiothor Vasc Anesth 17:686-690, 2003 13. Kogan A, Efrat R, Katz J, et al. Propofol-ketamine mixture for anesthesia in pediatric patients undergoing cardiac catheterization. J Cardiothor Vasc Anesth 17:691-693, 2003 14. Jobier A, Galal MO, Bulbul ZR, et al: Use of low-dose ketamine and/or midazolam for pediatric cardiac catheterization: Is an anesthesiologist needed? Pediatr Cardiol 24:236-243, 2003 15. Geva T, Griel GF, Marshall AC, et al: Gadolinium-enhanced 3-dimensional magnetic resonance angiography of pulmonary blood supply in patients with complex pulmonary stenosis or atresia: Comparison with x-ray angiography. Circulation 106:473-478, 2002 16. Trivedi KR, Asakie A, Benson LN: Collaborative interventional and surgical strategies in the management of congenital heart lesions. Semin Thorac Cardiovasc Surg Pediatr Card Surg Ann 4:185-207, 2001 17. Tworetsky W, Jennings RW, Wilkins-Haug LE, et al: Balloon dilation of severe aortic stenosis in the fetus: Technical advances. J Am Coll Cardiol 41:496A, 2003 (abstr) 18. Hornung TS, Benson LN, McLaughlin PR: Catheter interventions in adult patients with congenital heart disease. Curr Cardiol Rep 4:54-56, 2002