Perioperative Considerations for the Fontan Patient Requiring Noncardiac Surgery.

Children and adults with congenital heart disease undergoing noncardiac surgery are at higher risk of perioperative adverse events. Patients have significant comorbidities and syndromic associations that increase perioperative risk further. The complexity of congenital heart disease requires a thorough understanding of lesion-specific pathophysiology in order to provide safe care. Comprehensive multidisciplinary planning and the use of skilled and experienced teams achieve the best outcomes. The anesthesiologist is a perioperative physician charged with providing safe anesthesia care, instituting appropriate hemodynamic monitoring, and determining appropriate postoperative disposition on an individual basis.

Pediatric anesthesiology fellow education: is a simulation-based boot camp feasible and valuable?

BACKGROUND: Pediatric anesthesiologists must manage crises in neonates and children with timely responses and limited margin for error. Teaching the range of relevant skills during a 12-month fellowship is challenging. An experiential simulation-based curriculum can augment acquisition of knowledge and skills. OBJECTIVES: To develop a simulation-based boot camp (BC) for novice pediatric anesthesiology fellows and assess learner perceptions of BC activities. We hypothesize that BC is feasible, not too basic, and well received by fellows. METHODS: Skills stations, team-based in situ simulations, and group discussions of complex cases were designed. Stations were evaluated by anonymous survey; fellows rated usefulness in improving knowledge, self-confidence, technical skill, and clinical performance using a Likert scale (1 strongly disagree to 5 strongly agree). They were also asked if stations were too basic or too short. Median and interquartile range (IQR) data were calculated and noted as median (IQR). RESULTS: Fellows reported the difficult airway station and simulated scenarios improved knowledge, self-confidence, technical skill, and clinical performance. They disagreed that stations were too basic or too short with exception of the difficult airway session, which was too short [4 (4-3)]. Fellows believed the central line station improved knowledge [4 (4-3)], technical skills [4 (4-4)], self-confidence [4 (4-3)], and clinical performance [4 (4-3)]; scores trended toward neutral likely because the station was perceived as too basic [3.5 (4-3)]. An interactive session on epinephrine and intraosseous lines was valued. Complicated case discussion was of educational value [4 (5-4)], the varied opinions of faculty were helpful [4 (5-4)], and the session was neither too basic [2 (2-2)] nor too short [2 (2-2)]. CONCLUSION: A simulation-based BC for pediatric anesthesiology fellows was feasible, perceived to improve confidence, knowledge, technical skills, and clinical performance, and was not too basic.

The safety of modern anesthesia for children with long QT syndrome.

BACKGROUND: Patients with long QT syndrome (LQTS) may experience a clinical spectrum of symptoms, ranging from asymptomatic, through presyncope, syncope, and aborted cardiac arrest, to sudden cardiac death. Arrhythmias in LQTS are often precipitated by autonomic changes. This patient population is believed to be at high risk for perioperative arrhythmia, specifically torsades de pointes (TdP), although this perception is largely based on limited literature that predates current anesthetic drugs and standards of perioperative monitoring. We present the largest multicenter review to date of anesthetic management in children with LQTS. METHODS: We conducted a multicentered retrospective chart review of perioperative management of children with clinically diagnosed LQTS, aged 18 years or younger, who received general anesthesia (GA) between January 2005 and January 2010. Data from 8 institutions were collated in an anonymized database. RESULTS: One hundred three patients with LQTS underwent a total of 158 episodes of GA. The median (interquartile range) age and weight of the patients at the time of GA was 9 (3-15) years and 30.3 (15.4-54) kg, respectively. Surgery was LQTS-related in 81 (51%) GA episodes (including pacemaker, implantable cardioverter-defibrillator, and loop recorder insertions and revisions and lead extractions) and incidental in 77 (49%). ß-blocker therapy was administered to 76% of patients on the day of surgery and 47% received sedative premedication. Nineteen percent of patients received total IV anesthesia, 30% received total inhaled anesthesia, and the remaining 51% received a combination. No patient received droperidol. There were 5 perioperative episodes of TdP, all in neonates or infants, all in surgery that was LQTS-related, and none of which was overtly attributable to anesthetic regimen. Thus the incidence (95% confidence interval) of perioperative TdP in incidental versus LQTS-related surgery was 0/77 (0%; 0%-5%) vs 5/81 (6.2%; 2%-14%). CONCLUSIONS: With optimized perioperative management, modern anesthesia for incidental surgery in patients with LQTS is safer than anecdotal case report literature might suggest. Our series suggests that the risk of perioperative TdP is concentrated in neonates and infants requiring urgent interventions after failed first-line management of LQTS.

A neonate with long QT syndrome, refractory ventricular arrhythmias, and lidocaine toxicity.

Long QT syndrome is characterized by electrocardiographic appearance of long QT intervals and propensity to polymorphic ventricular tachycardia. Aggressive anticipatory clinical management is required for a good outcome, especially in the symptomatic neonate. We present a neonate with a compound mutation with refractory ventricular tachycardia that necessitated multimodal pharmacotherapy with lidocaine, esmolol, and amiodarone along with ventricular pacing. Despite normal serum lidocaine levels, complex pharmacokinetic interactions resulted in presumed neurotoxicity due to lidocaine. This report discusses the implications and challenges of management of a neonate with compound long mutations.

Implications of anesthesia in children with long QT syndrome.

BACKGROUND: Patients with congenital long QT syndrome (LQTS) are susceptible to an episodic malignant ventricular tachyarrhythmia known as torsade de pointes, which can result in a cardiac arrest and death. Patients can suffer severe cardiac events resulting in syncope, seizures, and sudden cardiac death during times of physical and emotional stress and when exposed to certain drugs including anesthetics. We describe the occurrence of perioperative adverse events (AEs) related to arrhythmias in children with congenital LQTS exposed to volatile general anesthesia and describe associated risk factors. METHODS: We performed a retrospective cohort study of children with LQTS undergoing general anesthesia for noncardiac surgery or device implant, or revision for cardiac rhythm management. This study was a retrospective chart review with data collection from computerized and electronic patient medical records. RESULTS: Seventy-six patients with congenital LQTS were identified who had a total of 114 anesthetic encounters. Of the 114 anesthetic encounters, there were 3 AEs, 2 definite and 1 probable AE, for an incidence of 2.6%. The events occurred in boys (aged 11, 13, and 15 years) while undergoing noncardiac surgery under volatile general anesthesia. All were receiving ß-blocker therapy preoperatively. The AEs occurred in close proximity to the administration of reversal drugs (anticholinesterase/anticholinergic combinations) and the antiemetic ondansetron. The events occurred during emergence from anesthesia, and exclusively in the group of patients who received both reversal drugs and ondansetron. All were treated successfully with short-term antiarrhythmic drug therapy and discharged the next morning. CONCLUSIONS: There is an increased risk of AEs during periods of enhanced sympathetic activity, especially emergence. This risk seems to be further enhanced if drugs are administered at this time that are known either to prolong the corrected QT interval or the transmural dispersion of repolarization or increase the incidence of tachycardia. Restriction of medications that adversely affect ion channels and intense vigilance and monitoring during this time and in the postoperative phase could help prevent occurrence or progression of AEs.

Assessment of parental decision-making in neonatal cardiac research: a pilot study.

OBJECTIVE: To assess parental permission for a neonate's research participation using the MacArthur competence assessment tool for clinical research (MacCAT-CR), specifically testing the components of understanding, appreciation, reasoning and choice. STUDY DESIGN: Quantitative interviews using study-specific MacCAT-CR tools. HYPOTHESIS: Parents of critically ill newborns would produce comparable MacCAT-CR scores to healthy adult controls despite the emotional stress of an infant with critical heart disease or the urgency of surgery. Parents of infants diagnosed prenatally would have higher MacCAT-CR scores than parents of infants diagnosed postnatally. There would be no difference in MacCAT-CR scores between parents with respect to gender or whether they did or did not permit research participation. PARTICIPANTS: Parents of neonates undergoing cardiac surgery who had made decisions about research participation before their neonate's surgery. METHODS: The MacCAT-CR. RESULTS: 35 parents (18 mothers; 17 fathers) of 24 neonates completed 55 interviews for one or more of three studies. Total scores: magnetic resonance imaging (mean 36.6, SD 7.71), genetics (mean 38.8, SD 3.44), heart rate variability (mean 37.7, SD 3.30). Parents generally scored higher than published subject populations and were comparable to published control populations with some exceptions. CONCLUSIONS: The MacCAT-CR can be used to assess parental permission for neonatal research participation. Despite the stress of a critically ill neonate requiring surgery, parents were able to understand study-specific information and make informed decisions to permit their neonate's participation.

Novel use of dexmedetomidine in a patient with pulmonary hypertension.

The presence of pulmonary arterial hypertension (PAH) is a significant predictor of major perioperative cardiovascular complications in patients undergoing cardiac diagnostic or interventional procedure or non cardiac surgery under sedation and/or anesthesia. Factors that precipitate a pulmonary hypertensive crisis include hypoxia, hypercarbia, acidosis, hypothermia, pain and airway manipulations. Pain management is challenging in patients with significant PAH. We report the use of dexmedetomidine for sedation and analgesia in a 16 year old patient with significant pulmonary hypertension, pneumonia and impending cardiorespiratory failure. This resulted in avoidance of endotracheal intubation and positive pressure ventilation, with subsequent recovery to discharge home.

Primary erythromelalgia in a child responding to intravenous lidocaine and oral mexiletine treatment.

Erythromelalgia is a rare, chronic, debilitating condition characterized by redness, warmth, and severe burning pain of the distal extremities. The feet are more commonly affected than the hands. Pain is precipitated by increases in temperature and by exercise. Patients often obtain relief by immersing the affected extremity in cold water. The pain is often refractory to treatment. For many patients, multiple pain medications have been useless in achieving complete relief of pain symptoms. Previous reports of erythromelalgia among adolescents indicated prolonged relief of pain with sodium nitroprusside infusions, epidural infusions of local anesthetics, or gabapentin treatment. We present a case of an 11-year-old, white, male child with primary erythromelalgia, whose initial symptoms started in his preschool years and whose childhood was marked by escalating episodes of pain with warmth and redness of his feet, precipitated especially by increases in temperature and by activity. All conventional pain management techniques had failed to relieve our patient of his symptoms, and he obtained some relief only by soaking his affected extremities in ice water. He had experienced minimal benefit from seeing a pain psychologist, who helped him develop techniques to cope with the pain. At the time of presentation, the patient's episodes of pain had increased to 15 to 20 per day, and there was evidence of chronic immersion injury to the skin of his feet. Before his most recent hospitalization, the pain had spread to involve his hands as well. The patient was overwhelmed with anxiety and could not participate in school or social activities at the time of admission. During his current hospitalization, he did show some therapeutic response to sodium nitroprusside infusion, which unfortunately had to be discontinued because of side effects and because his family desired to leave the ICU environment, which was stressful to the patient. He also had some response to lumbar epidural infusion of local anesthetics, which could not be continued because he found the motor blockade that accompanied his analgesia intolerable. However, intravenous lidocaine infusion, with subsequent transition to oral mexiletine therapy, proved very effective in reducing the frequency and severity of the pain episodes. The patient was discharged from the hospital with oral mexiletine therapy and has been monitored at the pain management clinic. He returned to and completed school, attended summer camp, and enjoys an active happy life. He walks without precipitating pain in his feet and sleeps 9 to 10 hours every night. He has needed to soak his feet on only 4 occasions in the 6 months since his discharge from the hospital. His quality of life has improved significantly. He has shown no evidence of liver toxicity, and his mexiletine levels have been stable.

Hyperkalemic cardiac arrest after cardiopulmonary bypass in a child with unsuspected duchenne muscular dystrophy.

Adverse reactions to volatile anesthetics and depolarizing muscle relaxants can occur in patients with Duchenne muscular dystrophy (DMD) resulting in acute rhabdomyolysis and hyperkalemia. We report a case of hyperkalemic cardiac arrest after cardiac surgery using cardiopulmonary bypass in a child with unsuspected DMD. Early diagnosis and management of hyperkalemia resulted in a successful outcome. Genetic testing confirmed the diagnosis of DMD. We recommend a thorough preoperative investigation, including creatine kinase estimation, in children with a history of unexplained motor delay.

Biodegradable self-assembling PEG-copolymer as vehicle for poorly water-soluble drugs.

PURPOSE: To develop self-assembling systems increasing the solubility of poorly water-soluble drugs. METHODS: Low molecular weight liquid biodegradable copolymers were synthesized by ring-opening polymerization using caprolactone (CAP) and trimethylenecarbonate (TMC) as monomers. Various initiators were evaluated. The emulsifying and self-assembling properties were investigated by a water titration method. The self-assembling systems were characterized for size, shape, isotropic behavior, cloud point, surface charge, and critical micellar concentration in order to optimize the polymer synthesis. Finally, the improvement of solubility of model drugs was assessed. RESULTS: Only diblock monomethyl ether PEG-CAP/TMC copolymers synthesized with monomethyl ether polyethyleneglycol 550 to 2000 as initiator have shown self-assembling properties: upon dilution, these copolymers formed an isotropically clear solution with droplet sizes in the range of 20 to 100 nm. The hypothesis that these diblock polymers form micelles was confirmed by their low critical micellar concentration (10(-5) g/ml). The copolymers initated with mmePEG750 had a higher cloud point and better colloidal stability than those initiated with mmePEG 550. The solubility of the poorly water-soluble drugs was increased by 1 to 2 orders of magnitude. Good reproducibility was observed from batch to batch. CONCLUSIONS: The polyester diblock copolymer mmePEG750-CAP/TMC forms spontaneously stable micelles in aqueous medium and increases the solubility of lipophilic drugs. They are very promising vehicles for the oral delivery of poorly water-soluble drugs.