Advances in postoperative care of pediatric cardiac patients Angela T. Zimmerman a and Laura M. Ibsen b

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1 Advances in postoperative care of pediatric cardiac patients Angela T Zimmerman a and Laura M Ibsen b Purpose of review The past two decades have seen tremendous technological advances in the care of infants and children with congenital and acquired heart disease Recent advances in postoperative management have made it possible to support smaller and more fragile infants, extended the capabilities of extracorporeal circulation, and have brought new and innovative monitoring capabilities to the intensive care unit Recent findings We chose to focus our review on four main themes: management of pulmonary hypertension, mechanical support of the myocardium, near infrared spectroscopy, and heparininduced thrombocytopenia Summary As operative and cardiopulmonary bypass techniques have evolved, early complete repair in neonates and repair of more complex lesions is now possible, creating new challenges for postoperative care in the intensive care unit Additionally, recognition and management of newly appreciated complications is essential Keywords pediatric cardiac care, pulmonary hypertension, mechanical circulatory support, heparin induced thrombocytopenia, cerebral oximetry Curr Opin Anaesthesiol 17: # 2004 Lippincott Williams & Wilkins a Department of Anesthesiology and Perioperative Medicine and b Department of Pediatrics, Oregon Health and Science University, Portland, Oregon, USA Correspondence to Angela T Zimmerman MD, Assistant Professor, Department of Anesthesiology and Perioperative Medicine, Oregon Health and Science University, 3181 SW Sam Jackson Park Road Mail Code UHS-2, Portland, OR , USA Tel: ; fax: ; zimmeran@ohsuedu Current Opinion in Anaesthesiology 2004, 17: Abbreviations CPB cardiopulmonary bypass ECMO extracorporeal membrane oxygenation HIT heparin-induced thrombocytopenia HPF4 heparin platelet factor 4 complex NIRS near-infrared spectroscopy PVRI pulmonary vascular resistance index VAD ventricular assist device # 2004 Lippincott Williams & Wilkins Introduction The 1980s and 1990s saw tremendous growth and development in congenital heart surgery and perioperative care With advancements in preoperative diagnosis and management, intraoperative bypass and anesthetic management techniques, and evolving surgical techniques, younger, smaller, and more complex postoperative patients are now being cared for in the intensive care unit New discoveries and continual refinement of management strategies have allowed for improvements in morbidity and mortality in the postoperative period Pulmonary hypertension Pulmonary hypertension can be the result of increased pulmonary vascular resistance or of increased pulmonary blood flow with normal pulmonary vascular resistance, or a combination of the two For the past two decades there has been a tremendous increase in our understanding of the role of the endothelium in influencing pulmonary vascular resistance through the expression of prostacyclin, endothelins, and nitric oxide, as well as their receptors and metabolism The effects of cardiopulmonary bypass (CPB) on the endothelium and the impact on postoperative pulmonary hypertension have been become appreciated Despite these advances, pulmonary hypertension and pulmonary hypertensive crises remain a significant cause of morbidity and mortality in the postoperative setting Inhaled nitric oxide has emerged as an important therapy for postoperative patients with pulmonary hypertension As yet, however, there have been no randomized, placebo-controlled trials on nitric oxide in pediatric postoperative congenital heart patients and the treatment remains FDA approved only for use in term and near term neonates with persistent pulmonary hypertension of the newborn Nevertheless, the use of inhaled nitric oxide in the postoperative setting has become commonplace Problems with rebound pulmonary hypertension upon withdrawal of inhaled nitric oxide have prompted the use of sildenafil, a selective phosphodiesterase 5 inhibitor Inhaled nitric oxide increases cyclic GMP, which is in turn broken down by phosphodiesterase 5 in the lung It appears that oral administration of sildenafil may allow for successful withdrawal of inhaled nitric oxide [1] Intravenous sildenafil was studied in the cardiac catheterization laboratory and in postoperative children with congenital heart disease and moderately increased pulmonary vascular resistance In nonoperative patients, sildenafil was more effective than inhaled nitric oxide (20 ppm) in reducing pulmonary vascular resis- DOI: /01aco

2 242 Paediatric anaesthesia tance index (PVRI) In postoperative patients, both inhaled nitric oxide and sildenafil reduced PVRI and though there was a trend towards improved reduction with sildenafil, it was not statistically significant [2 ] Most studies have used inhaled nitric oxide during mechanical ventilation, but investigators have begun to look for ways to deliver nitric oxide for longer-term treatment or for pre- or postoperative treatment that does not involve invasive mechanical ventilation In one study [3 ], the authors describe the feasibility and efficacy of a novel pulsed nasal nitric oxide delivery system in pediatric patients with pulmonary hypertension Pulsed delivery of nitric oxide decreased mean PAP, PVRI, and Rp/Rs Seven of the 26 patients studied had congenital heart disease Epoprostenol (prostacyclin or prostaglandin I 2 ) has been well documented to improve hemodynamics in patients with primary pulmonary hypertension and is sometimes used in those with pulmonary hypertension secondary to congenital heart disease Epoprostenol, however, requires continuous intravenous infusion and may be associated with adverse effects, prompting investigations of analogs of the drug or different methods of administration McLaughlin et al [4 ] looked at the use of treprostinil given via continuous subcutaneous infusion in adults with primary pulmonary hypertension They found trends towards improvement in cardiac index and PVRI Iloprost is a stable derivative of prostaglandin I 2 that has been shown to be effective when given as an inhalation treatment to patients with primary pulmonary hypertension [5] Hallioglu et al [6 ] studied intravenous versus aerosolized iloprost in the catheterization lab in children with congenital heart disease and found that aerosolized iloprost led to significant reductions in Rp/Rs There have also been case reports and small series examining inhaled iloprost during weaning from CPB complicated by pulmonary hypertension [7,8] Another strategy being investigated involves manipulation of endothelin receptors [9] BQ-123 is a selective endothelin A receptor antagonist In a trial of adult and pediatric patients with severe chronic pulmonary hypertension due to autoimmune, primary or congenital heart disease, short-term infusion induced hemodynamic improvement, with reduced PVRI and improved or unchanged cardiac index [10 ] The effects of CPB on the endothelium and consequently on the development of postoperative pulmonary hypertension remain the focus of active investigation In one study, urea cycle function in pediatric patients with VSD (Ventricular septal defect) and AVSD (atrioventricular septal defect) who underwent CPB and repair was studied CBP caused a significant decrease in urea cycle intermediates at all time points measured and the ratios indicated decreased urea cycle function Nitric oxide metabolites were also significantly decreased compared with preoperative levels Arginine is the precursor to the formation of endogenous nitric oxide and the authors speculate that decreased availability of nitric oxide precursors may contribute to increased risk of postoperative pulmonary hypertension [11 ] Mechanical circulatory support Mechanical support of the circulation plays an increasing role in the perioperative care of pediatric patients with congenital or acquired heart disease Goals of such therapy may be a bridge to heart transplantation or a bridge to recovery Extracorporeal membrane oxygenation (ECMO) is the most frequently used form of circulatory support for pediatric patients, along with older centrifugal ventricular assist devices (VADs) Newer pulsatile or implantable VADs that are available for use in adults are not yet developed or available for use in infants and small children in the United States There have been several reports documenting the experiences of individual centers in their use of mechanical support Gajarski et al [12 ] reviewed their experience with ECMO instituted for ventricular failure in 145 patients over a 10-year period Twenty-one patients were listed for transplant, 12 received a transplant, and 10 survived to hospital discharge Five of those listed for transplant were able to be weaned off ECMO Seventeen of the 21 listed patients had congenital heart disease with postoperative ventricular dysfunction and 11 were infants Renal dysfunction was noted to be a significant risk factor for mortality Among the patients not listed for transplantation, 46% survived to hospital discharge In total, 95% of the nonlisted survivors were weaned from ECMO after a median support of 43 days [12 ] Another report from the same institution looked more specifically at the use of ECMO within 7 days of surgery for congenital heart disease Seventy-four patients were identified, with a 50% overall survival Children with an adequate two-ventricle repair were more likely to survive (58%) than those with a single ventricle (34%), and again renal failure was a significant risk factor for mortality Of this cohort, 14 patients were listed for transplant while on ECMO, eight were transplanted, and six survived to hospital discharge Only four of the cohort who were supported for more than 7 days survived [13 ] Fiser et al [14 ] reviewed their institution s experience with ECMO as a bridge to heart transplant They reported on 47 patients, of whom 16 were successfully bridged to transplant (nine long-term survivors) and 13

3 Advances in postoperative care Zimmerman and Ibsen 243 weaned from ECMO Survival rates were better in patients with cardiomyopathy (59%) compared with those with congenital heart disease (20%) The use of ECMO in the support of patients after heart transplantation has also been reported Fenton and colleagues [15 ] report on their experience over a 20- year period, during which time 168 patients underwent heart transplantation and 20 required ECMO for ventricular dysfunction, 15 immediately or within 6 weeks of surgery, and five at a later date In the perioperative ECMO group, eight (53%) survived to discharge Two of five who were placed on ECMO late survived to hospital discharge While there has been a significant amount of work done on long-term neuro-developmental follow up of neonates supported with ECMO for persistent pulmonary hypertension of the newborn, there is much less information available on patients supported with ECMO for purely cardiac indications Hamrick et al [16 ] described 14 ECMO survivors (of 53) supported with ECMO after cardiac surgery Seven of 14 had normal cognitive outcome, three had suspect outcome, and four were abnormal Ten of 14 had normal motor outcome, one had suspect outcome, and three were abnormal Mechanical support of the myocardium has traditionally been applied after the patient has failed conventional supportive therapy Ungerleider et al [17 ] presented a novel strategy utilizing an ECMO circuit without an oxygenator as an assist device in all patients who undergo Norwood or Damus-Kaye-Stansel with arch reconstruction The systemic-pulmonary shunt is left open and an oxygenator is not utilized The rationale for prophylactic use is twofold Mechanical support ensures cardiac output during the vulnerable postoperative period when such patients may have unexplained or difficult to predict hemodynamic deterioration Possibly more intriguing, adequate cerebral oxygen delivery during the vulnerable postoperative period and potentially improved neuro-developmental outcome may be possible In the report they combined the results from two institutions that utilize this strategy: 16 of 18 patients survived to hospital discharge Perhaps more significantly, neuro-developmental testing was performed on eight patients prior to Glenn and all were normal [17 ] Mechanical support of the circulation in pediatric patients has typically been accomplished with ECMO or centrifugal VAD There are currently no pulsatile or implantable VADs available for infants or small children in the United States, although some older children and adolescents are supported with VADs developed for adults Among other advantages, children supported by VADs may be more likely to be extubated or fed orally, thus improving their quality of life during the period of circulatory support [18] Merkle and colleagues [19 ] have described their experience in Germany with the Berlin heart VAD in 45 pediatric patients Seventeen patients were transplanted after support for days, and there were 12 long-term survivors They found that, during support, extubation, mobilization, and enteral nutrition were possible Over the last two decades, a wide variety of mechanical support devices have been developed worldwide Deng et al [20 ] described the establishment of an international database (MCSD, Mechanical Circulatory Support Database) of mechanical support devices in an attempt to generate data on the effectiveness of such devices and report on the first year s data The stated purposes of the database are to capture worldwide data relating to the implantation and outcome of patients receiving cardiac assist devices designed for and capable of use for more than 30 days, to identify risk factors for complications, to improve patient selection and treatment before and after device implantation, and in general to identify overall best practices with the aim of improving current practices Clearly, the majority of the patients in the database will be adults or older adolescents, but with time and the development of such technology for infants and children, the database may help to capture cumulative information on their outcomes as well Monitoring with near-infrared spectroscopy Near-infrared spectroscopy (NIRS) has been documented for use in monitoring cerebral oxygenation The technology has been available for the last several years using the INVOS cerebral oximeter (Somanetics, Troy, Michigan, USA) The intent is to continuously monitor changes in the regional perfusion of the brain during a variety of clinical conditions in a noninvasive manner The trend of values may prompt changes in the management of care to improve outcome Since many pediatric cardiac patients undergo surgeries involving CPB, they are at risk for neurological complications Interventions based on trends in cerebral oximetry have been shown to decrease the incidence of postoperative neurological complications, with the potential of reducing length of hospital stay and overall costs [21] Postoperative use of this monitoring has been shown to be helpful in the setting of stage 1 palliation surgery for single ventricle defects, where the balance of systemic and pulmonary perfusion must be optimally managed NIRS monitoring appears helpful in assessing systemic perfusion Cerebral oxygenation values correlate with several commonly used methods of estimating systemic perfusion such as base excess and lactic acid [22 ] NIRS technology can be expanded to provide regional tissue

4 244 Paediatric anaesthesia perfusion at sites other than the brain The monitoring patch can be placed at the flank in the thoracolumbar area to measure renal oximetry [23 ] The combination of having cerebral and renal oximetry may provide an estimate of venous saturation that is otherwise obtained invasively with an oximetric catheter in the superior vena cava [24 ] Calculation of venous saturation from cerebral and renal saturations, however, is somewhat complex It must be emphasized again, therefore, that the value of using NIRS is in having a continuous monitor to follow trends so that therapeutic maneuvers are made expeditiously when the NIRS reading indicates a low perfusion state Heparin-induced thrombocytopenia Heparin-induced thrombocytopenia (HIT) is a common and well known complication of heparin therapy To briefly review, HIT is an immune-mediated, platelet activation syndrome Heparin forms a complex with platelet factor 4 (HPF4), which is released from platelets by platelet activation Antibodies are formed against the HPF4 complex The antibody HPF4 complex binds to the platelet Fc receptor leading to platelet activation and generation of procoagulant platelet microparticles The result is thrombosis and thrombocytopenia Endothelial cells and monocytes also appear to be targets of the HIT immune complexes (B Alsoufi, L Boshkov, A Kirby, et al, in preparation) HIT occurs in 1 4% of adults exposed to heparin Despite the thrombocytopenia, the major clinical problem is thrombosis HIT-associated thrombosis occurs in 29 88% of these patients and carries a high morbidity (38 81%) and mortality (20 30%) In HIT, the decrease in platelets is usually 40 50% and the onset is 5 10 days after first exposure to heparin and hours to 2 3 days with re-exposure [25] (B Alsoufi, L Boshkov, A Kirby, et al, in preparation) Little is known about the incidence of HIT in children, however, and most data in the past have been limited to anecdotal or case reports HIT-associated thrombosis develops in critically ill neonates, infants, and children who receive heparin for a variety of reasons such as prevention and therapy of thrombosis and maintaining vascular catheter patency Heparin is extensively used in congenital cardiac patients, especially those with angiography, CPB, extracorporeal membrane oxygenations, and VADs [25,26] (B Alsoufi, L Boshkov, A Kirby, et al, in preparation) There has been an increasing awareness of HIT and its treatment in the pediatric population and this awareness has generated a few publications recently Schmugge et al [25] performed a retrospective cohort study to determine the incidence of HIT-associated thrombosis in a multidisciplinary pediatric intensive care unit Over a 30-month interval, 612 patients received heparin for more than 5 days Thrombosis occurred in 57 patients (93%) Plasma samples were available for 38 cases, of which 14 satisfied clinical HIT criteria The calculated incidence rate for HIT-associated thrombosis was 23% These 14 patients suffered from either venous, arterial, or combined arterial and venous thrombosis, but none died or underwent amputation The conclusion was that HIT-associated thrombosis in pediatric intensive care unit patients has a similar incidence but a less severe outcome compared with the data reported for adults The authors believe that the true incidence of HIT was even higher than the stated 23%, as only the children with radiologically documented thromboembolism were included Porcelli et al [27 ] performed a retrospective review of all children who had cardiac surgery at their institution and reported two cases of HIT with associated thrombosis over a 5-year span Both patients developed HIT after the Fontan operation One patient subsequently died The other patient had a complicated hospital stay, which ultimately resulted in a limb amputation because of gangrene This second case showed that thrombosis developed very rapidly, only a few hours after heparin re-exposure, as the patient had a cardiac catheterization where heparin was used 2 weeks previously Newall et al [28 ] performed a 1-week audit of heparin use in their tertiary care pediatric hospital, a retrospective medical record review of all suspected HIT cases over a 2-year period, and a literature review The retrospective review identified four patients with suspected or confirmed cases of HIT It was acknowledged, however, that the method used to identify these patients may not have fully captured all patients who might have actually had HIT Three out of these four patients had underlying cardiac defect and two had CPB Two developed thrombotic complications, which proved fatal in one patient The audit confirmed the extensive use of heparin that, when extrapolated, would suggest a higher incidence of HIT in children The authors concluded that the occurrence of HIT in children is much lower than that reported in adults, but improved laboratory techniques could better facilitate screening and diagnosis Etches et al [29 ] performed a prospective study to determine the incidence of HIT in a pediatric intensive care unit A positive HIT assay was found in three of 233 patients The samples were obtained between 10 and 21 days of intensive care unit admission and all three patients had undergone cardiac surgeries None had a platelet fall of over 50%, nor clinical evidence of thrombosis An additional five cardiac patients had

5 Advances in postoperative care Zimmerman and Ibsen 245 equivocal results on the HIT assay One of these five showed clinical HIT with a platelet fall of over 50% and a thrombotic event The study suggests that the incidence is low and that thrombocytopenia associated with cardiac surgery is multifactorial Furthermore it was shown that HIT assays can be difficult to interpret Boshkov et al reported 10 cases of HIT, confirmed by functional HIT assays, in our pediatric intensive care unit in the past 2 years Nine of the 10 were congenital cardiac patients an incidence of 13% This is comparable to the 1 3% rate reported in the adult cardiac surgery literature The nine cardiac patients ranged in age from 2 weeks to 5 years Two, both neonates, died of HIT-related thrombosis (mortality 22%) Again, this mortality rate is comparable to the 28% reported in the largest adult cardiac series An additional three patients suffered significant thrombotic morbidity, giving an overall thrombotic rate of 66% (38 81% reported in adults) The conclusion was that neonates and young children do make pathogenic HIT antibodies and that HIT in congenital cardiac surgery patients seems to have an incidence, morbidity and mortality comparable to that in adult cardiac surgery (B Alsoufi, L Boshkov, A Kirby, et al, in preparation) As the awareness and index of suspicion for pediatric HIT increases, so does the need to better understand treatment modalities A detailed discussion of treatment in adult cardiac patients can be found in the recent literature [30 ] Patients with a history of HIT who require anticoagulation with heparin for procedures such as cardiac catherization and subsequent cardiac operations require an alternate anticoagulant Similarly, patients with acute HIT require anticoagulation even if there is no evidence of a thrombus, given the unfavorable nature of the disease (B Alsoufi, L Boshkov, A Kirby, et al, in preparation) The agents with the most data available include danaparoid sodium (a heparinoid) and direct thrombin inhibitors lepirudin (recombinant hirudin) and argatroban None of these agents is approved for pediatrics There have been a few reports, however, of their successful application in pediatric HIT Severin et al [31] reported using danaparoid sodium in 16 patients and lepirudin in four patients The age range was 7 months to 17 years Effective anticoagulation and clinical improvement were observed in most patients The availability of danaparoid, however, can be problematic (B Alsoufi, L Boshkov, A Kirby, et al, in preparation) Cetta et al [32 ] reported the successful use of argatroban during a coil embolization of a Fontan fenestration in a 6-year-old child with a history of HIT At our institution, argatroban is normally the agent used to treat pediatric patients in both acute phase HIT and for therapeutic procedures in those with a known diagnosis of HIT As reported by Boshkov and colleagues [33 ] (B Alsoufi, L Boshkov, A Kirby, et al, in preparation), argatroban was used in eight patients, age range 1 week to 5 years Included in the report was the use of argatroban for a neonate on extracorporeal membrane oxygenation, an infant undergoing CPB, and a 3-year-old on hemodialysis In summary, patients on argatroban therapy need all coagulation measurements to be closely monitored in the context of clinical variables such as hepatic function, fibrinogens, and transfusions of blood products Again emphasized is the need for further studies to determine the safe and efficacious use of this drug in children Conclusion The postoperative care of pediatric cardiac patients has evolved with and will continue to mature in parallel with changes and improvements in preoperative management, surgical techniques, and CPB There is no doubt that during the past decade, improvements in many aspects of pediatric cardiac care have significantly improved survival of those previously thought to have a poor prognosis Advances in the postoperative care of these survivors have also contributed to overall survival We have highlighted four areas that have appeared to gain attention this past year: the treatment of pulmonary hypertension, the use of mechanical devices for maintenance of cardiac output, cerebral oxygenation monitoring with NIRS, and HIT Although knowledge was gained in these areas, continuing studies will hopefully answer questions raised from the clinical environment References and recommended reading Papers of particular interest, published within the annual period of review, have been highlighted as: of special interest of outstanding interest 1 Atz AM, Wessel DL Sildenafil ameliorates effects of inhaled nitric oxide withdrawal Anesthesiology 1999; 91: Schulze-Neick I, Hartenstein P, Li J, et al Intravenous sildenafil is a potent pulmonary vasodilator in children with congenital heart disease Circulation 2003; 108 (Suppl 10): Intravenous sildenafil was studied and compared with inhaled nitric oxide in the cardiac catheterization lab and in postoperative children with congenital heart disease and moderately increased pulmonary vascular resistance Cyclic GMP levels were also measured 3 Ivy DD, Parker D, Doran, A, et al Acute hemodynamic effects and home therapy using a novel pulsed nasal nitric oxide delivery system in children and young adults with pulmonary hypertension Am J Cardiol 2003; 92: The authors describe the feasibility and efficacy of a novel pulsed nasal nitric oxide delivery system in pediatric patients with pulmonary hypertension 4 McLaughlin VV, Gaine SP, Barst RJ, et al Efficacy and safety of treprostinil: an epoprostenol analog for primary pulmonary hypertension J Cardiovasc Pharmacol 2003; 41: This study was carried out in adults with primary pulmonary hypertension Treprostinil was given via continuous subcutaneous infusion, and showed trends toward improvement in cardiac index and PVRI 5 Olschewski H, Simonneau G, Nazzareno G, et al Inhaled iloprost for severe pulmonary hypertension New Engl J Med 2002; 347:

6 246 Paediatric anaesthesia 6 Hallioglu O, Dilber E, Celiker P Comparison of acute hemodynamic effects of aerosolized and intravenous iloprost in secondary pulmonary hypertension in children with congenital heart disease Am J Cardiol 2003; 92: Intravenous versus aerosolized iloprost was studied in children with pulmonary hypertension due to congenital heart disease Aerosolized iloprost led to a significant decrease in Rp/Rs, whereas intravenous iloprost reduced systemic arterial pressure 7 Muller M, Scholz S, Kwapisz M, et al Use of inhaled iloprost in a case of pulmonary hypertension during pediatric congenital heart surgery Anesthesiology 2003; 99: Langer F, Wilhelm W, Tscholl D, et al Intraoperative inhalation of the longacting prostacyclin analog iloprost for pulmonary hypertension J Thorac Cardiovasc Surg 2003; 126: Schulze-Neick I, Li J, Reader JA, et al The endothelin antagonist BQ123 reduces pulmonary vascular resistance after surgical intervention for congenital heart disease J Thorac Cardiovasc Surg 2002; 124: Apostolopoulou SC, Rammos S, Kyriakides ZS, et al Acute endothelin A receptor antagonism improves pulmonary and systemic haemodynamics in patients with pulmonary arterial hypertension that is primary or autoimmune and related to congenital heart disease Heart 2003; 89: The authors showed that BQ-123, a selective endothelin A receptor antagonist, induced hemodynamic improvement in severe chronic pulmonary hypertension in three groups autoimmune, primary, and due to congenital heart disease when given as a short-term infusion 11 Barr FE, Beverly H, VanHook K, et al Effect of cardiopulmonary bypass on urea cycle intermediates and nitric oxide levels after congenital heart surgery J Pediatr 2003; 142:26 30 The authors studied urea cycle intermediates as well as nitric oxide metabolites in pediatric patients with VSD and AVSD who underwent CPB and repair 12 Gajarski RJ, Mosca RS, Ohye RG, et al Use of extracorporeal life support as a bridge to pediatric cardiac transplantation J Heart Lung Transplant 2003; 22:28 34 The authors reviewed a single institution s experience with ECMO instituted for ventricular failure Most patients who were not listed for transplant were weaned from ECMO after a median support of 43 days Renal failure was a significant negative prognostic factor 13 Kolovos NS, Bratton SL, Moler FW, et al Outcome of pediatric patients treated with extracorporeal life support after cardiac surgery Ann Thorac Surg 2003; 76: The authors describe their single institution s experience with ECMO within 7 days of surgery They concluded that patients with single ventricle physiology, continued elevation of lactate after institution of ECMO, and development of renal failure have increased risk of death 14 Fiser WP, Yetman AT, Gunselman RJ, et al Pediatric arteriovenous extracorporeal membrane oxygenation (ECMO) as a bridge to cardiac transplantation J Heart Lung Transplant 2003; 22: The authors reviewed a single institution s experience with ECMO as a bridge to heart transplant There were 47 patients, of whom 16 were successfully bridged to transplant (nine long-term survivors) and 13 weaned from ECMO Survival was better in patients with cardiomyopathy (59%) than those with congenital heart disease (20%) 15 Fenton KN, Webber SA, Danford DA, et al Long-term survival after pediatric cardiac transplantation and postoperative ECMO support Ann Thorac Surg 2003; 76: The authors describe their institution s experience with ECMO after cardiac transplantation They found that mechanical circulatory support can be a useful strategy in the management of graft dysfunction after pediatric cardiac transplantation both early and late 16 Hamrick SE, Gremmels DB, Keet CA, et al Neurodevelopmental outcome of infants supported with extracorporeal membrane oxygenation after cardiac surgery Pediatrics 2003; 111: The authors describe the neurodevelopmental outcome of patients supported postoperatively with ECMO 17 Ungerleider RM, Shen I, Yeh T, et al Routine mechanical ventricular assist following the Norwood procedure: improved neurologic outcome and excellent hospital survival Ann Thorac Surg 2004; 77:18 22 The authors developed a strategy of prophylactically placing all patients who underwent Norwood operation or Damus-Kaye-Stansel with arch reconstruction on a VAD circuit immediately following untrafiltration, using the CPB cannulae They discuss the advantages of providing guaranteed cardiac output in the vulnerable immediate postoperative period, as well as providing adequate cerebral oxygen delivery and potential improvement in neurodevelopmental outcome 18 Levi D, Marelle D, Plunkett M, et al Use of assist devices and ECMO to bridge pediatric patients with cardiomyopathy to transplant J Heart Lung Transplant 2002; 21: The authors describe their institution s experience with VAD and ECMO as a bridge to transplant for patients with cardiomyopathy 19 Merkle F, Boettcher W, Stiller B, Hetzer R Pulsatile mechanical cardiac assistance in pediatric patients with the Berlin heart ventricular assist device J Extra Corpor Technol 2003; 35: This paper is a single institution report of the experience over 14 years with the Berlin Heart VAD There was poor survival when this tool was used as a rescue device after surgery for congenital heart disease or early graft failure after transplantation Advantages include extubation and mobilization 20 Deng MC, Edwards LB, Mertz MI, et al Mechanical Circulatory Support Device Database of the International Society for Heart and Lung Transplantation: first annual report J Heart Lung Transplant 2003; 22: The authors describe the establishment of an international database of mechanical support devices in an attempt to generate data on the effectiveness of such devices and report on the first year s data This report highlights the importance and difficulties of such a database 21 Austin E, Edmonds H, Auden S, et al Benefits of neurophysiologic monitoring for pediatric cardiac surgery J Thorac Cardiovasc Surg 1997; 717: Tosone S, Miller B, Guzzetta N, et al Cerebral oxygen saturation monitoring is a useful adjunct in assessing adequacy of systemic perfusion in single ventricle physiology after neonatal cardiac surgery [abstract] Lippincott Williams & Wilkins, London, England In: 2003 ASA meeting abstracts; abstract 1392 Interesting study comparing NIRS with traditional methods of determining single ventricle function following Norwood operation 23 Berens R, Hoffman G, Robertson F, et al Near infrared oximetry (NIRS) allows noninvasive assessment of regional oxygenation during pediatric coarctation repair [abstract] In: 2003 ASA meeting abstracts; abstract 1386 Describes a novel application of NIRS to assess renal perfusion 24 Hoffman G, Stuth E, Berens R, et al Two-site near-infrared transcutaneous oximetry as a non-invasive indicator of mixed venous oxygen saturation in cardiac neonates [abstract] In: 2003 ASA meeting abstracts; abstract 1393 Provides an intriguing hypothesis that mixed venous oxygen saturation, usually monitored invasively, can be estimated by noninvasive measures using NIRS 25 Schmugge M, Lorenz R, Huber A, et al Heparin-induced thrombocytopeniaassociated thrombosis in pediatric intensive care patients Pediatrics 2002; 109(1) e10/ Severin T, Sutor A Heparin-induced thrombocytopenia in pediatrics Semin Thromb Hemost 2001; 27: Porcelli R, Moskowitz B, Cetta F, et al Heparin-induced thrombocytopenia with associated thrombosis in children after the Fontan operation Tex Heart Inst J 2003; 30:58 61 Report of two cases of HIT found in a retrospective review of records 28 Newall F, Barnes C, Ignjatovic V, et al Heparin-induced thrombocytopenia in children J Paediatr Child Health 2003; 39: General overview, retrospective study and literature review to determine the occurrence of HIT 29 Etches W, Stang L, Conradi A Incidence of heparin-induced thrombocytopenia in a pediatric intensive care population Blood 2003; 102:536 A prospective study, whereas most studies have been retrospective, to determine the incidence of HIT 30 Warkentin T, Greinacher A Heparin-induced thrombocytopenia and cardiac surgery Ann Thorac Surg 2003; 76: Detailed discussion of the treatment of HIT in adult cardiac surgery 31 Severin T, Zieger B, Sutor A Anticoagulation with recombinant hirudin and danaparoid sodium in pediatric patients Semin Thromb Hemost 2002; 28: Cetta F, Graham L, Wrona L, et al Argatroban use during pediatric interventional cardiac catheterization Catheter Cardiovasc Interv 2004; 61: Good case report that discusses an appropriate use of argatroban 33 Boshkov L, Dower N, Kirby A, et al Argatroban for neonates and young children with heparin-induced thrombocytopenia: infusion, catherization, ECMO, cardiopulmonary bypass and hemodialysis Blood 2003; 102:326 Very informative description of the use of argatroban for HIT in several challenging clinical situations