Initially described in 1948 by Hertert thromboelastography (TEG) provides a real-time assessment of viscoelastic clot strength in whole blood. Rotational thromboelastometry (ROTEM) evolved from TEG technology and both devices generate output by transducing changes in the viscoelastic strength of a small sample of clotting blood (300 ml) to which a constant rotational force is applied. These point of care devices allow visual assessment of blood coagulation from clot formation, through propagation, and stabilization, until clot dissolution. Computer analysis of the output allows sophisticated clot formation/dissolution kinetics and clot strength data to be generated. Activation of clot formation can be initiated with both intrinsic (kaolin, ellagic acid) and extrinsic (tissue factor) activators. In addition, the independent contributions of platelets and fibrinogen to final clot strength can be assessed using added platelet inhibitors (abciximab and cytochalasin D). Increasingly, ROTEM and TEG analysis is being incorporated in vertical algorithms to diagnose and treat bleeding in high-risk populations such as those undergoing cardiac surgery or suffering from blunt trauma. Some evidence suggests these algorithms might reduce transfusions, but further study is needed to assess patient outcomes.

Dexmedetomidine in high doses provides adequate sedation for pediatric MRI studies. While use of high dose dexmedetomidine is associated with decreases in heart rate and blood pressure outside the established 'awake' norms, this deviation is generally within 20% of norms, and is not associated with adverse sequelae. Dexmedetomidine is useful as the sole sedative for pediatric MRI.

The results of this controlled effectiveness trial support routine use of microstream capnography to detect alveolar hypoventilation and reduce hypoxemia during procedural sedation in children. In addition, capnography allowed early detection of arterial oxygen desaturation because of alveolar hypoventilation in the presence of supplemental oxygen. The current standard of care for monitoring all patients receiving sedation relies overtly on pulse oximetry, which does not measure ventilation. Most medical societies and regulatory organizations consider moderate sedation to be safe but also acknowledge serious associated risks, including suboptimal ventilation, airway obstruction, apnea, hypoxemia, hypoxia, and cardiopulmonary arrest. The results of this controlled trial suggest that microstream capnography improves the current standard of care for monitoring sedated children by allowing early detection of respiratory compromise, prompting intervention to minimize hypoxemia. Integrating capnography into patient monitoring protocols may ultimately improve the safety of nonintubated patients receiving moderate sedation.

Patients with congenital supravalvular aortic stenosis and associated peripheral pulmonary artery stenoses, the majority of whom have Williams-Beuren syndrome, are inherently at risk for development of myocardial ischemia. This is particularly true in the setting of procedural sedation and anesthesia. The biventricular hypertrophy that accompanies these lesions increases myocardial oxygen consumption and compromises oxygen delivery. In addition, these patients often have direct, multifactorial compromise of coronary blood flow. In this article, we review both the pathophysiology of congenital supravalvular aortic stenosis and the literature regarding sudden death in association with sedation and anesthesia. Recommendations as to preoperative assessment and management of these patients are made based on the best available evidence.

Background-Near-infrared spectroscopy monitoring of cerebral oxygen saturation (rSO 2 ) has become routine in many centers, but no studies have reported the relationship of intraoperative near-infrared spectroscopy to long-term neurodevelopmental outcomes after cardiac surgery. Methods and Results-Of 104 infants undergoing biventricular repair without aortic arch reconstruction, 89 (86%) returned for neurodevelopmental testing at 1 year of age. The primary near-infrared spectroscopy variable was the integrated rSO 2 (area under the curve) for rSO 2 Յ45%; secondary variables were the average and minimum rSO 2 by perfusion phase and at specific time points. Psychomotor and mental development indexes of the Bayley scales, head circumference, neurological examination, and abnormalities on brain magnetic resonance imaging did not differ between subjects according to a threshold level for rSO 2 of 45%. Lower Psychomotor Development Index scores were modestly associated with lower average (rϭ0.

At 1.0 and 1.5 MAC, sevoflurane was well tolerated by healthy volunteers. At 2.0 MAC, in subjects with mean arterial pressure > or = 50 mmHg, no adverse cardiovascular properties were noted. Similar to other contemporary anesthetics, sevoflurane caused evidence of myocardial depression. Hemodynamic instability was noted in some subjects at high anesthetic concentrations in the absence of surgical stimulation. The incidence was similar to that with isoflurane. The cardiovascular effects of sevoflurane were similar to those of isoflurane, an anesthetic commonly used in clinical practice since 1981.

Procoagulant and anticoagulant factor levels were significantly lower in patients after the Fontan operation independent of hemodynamic variables peculiar to the Fontan circulation. Increased factor VIII level requires further evaluation as a cause of thrombosis in patients with Fontan physiology and may also indicate a subset of these patients in whom anticoagulation is indicated.

Children with major and severe CHD, undergoing noncardiac surgery, have an increased risk of mortality compared with children without CHD. Further studies need to identify the optimal environment for surgical procedures, develop trained multidisciplinary teams to care for children with CHD, and define management strategies for improving outcomes in this high-risk population.