Michael J. Eisses

Cardiopulmonary Bypass Parameters and Hemostatic Response to Cardiopulmonary Bypass in Infants Versus Children

OBJECTIVE Because infants have relatively more blood loss (mL/kg) than older children during cardiac surgery involving cardiopulmonary bypass (CPB), the authors compared hemostatic activation between infants and older children undergoing cardiac surgery. DESIGN Observational study. SETTING University-affiliated childrens hospital. PARTICIPANTS Twenty-eight children (18 infants <1 year and 10 children >1 year) undergoing cardiac surgery with CPB. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Markers of coagulation and fibrinolysis were evaluated at 9 sample points before, during, and after CPB in the 28 children. Infants had greater chest tube output, longer CPB times, and a larger drop in platelet counts during CPB than children. Active tissue plasminogen activator (tPA) increased during CPB in both groups, with infants showing lower levels than children (p < 0.001). In both groups, active plasminogen activator inhibitor type 1 (PAI-1) first decreased during CPB and then increased above baseline postoperatively. Infants had higher PAI-1 than children near the end of CPB (p = 0.01). Thrombin-antithrombin complex levels increased during and after CPB, with infants showing lower levels only during CPB (p = 0.01). D-dimer and prothrombin activation peptide (F1.2) levels increased in a similar pattern for both groups during and after CPB. The length of aortic cross-clamp time and the level of F1.2 after protamine administration correlated significantly and independently with 12-hour chest tube output. CONCLUSIONS Compared with children, infants had greater blood loss (mL/kg), greater drop in platelets during CPB, lower active tPA, and higher active PAI-1. Cumulative thrombin generation after CPB, indicated by F1.2 levels, correlated with early blood loss.

Reducing hemostatic activation during cardiopulmonary bypass: a combined approach.

Interventions such as heparin-coated circuits, ε-aminocaproic acid, and reduced shed blood reinfusion have shown mixed results when applied individually for limiting hemostatic activation during cardiopulmonary bypass (CPB). We compared coagulation and fibrinolytic activation during conventional CPB (control) (CTRL) using noncoated circuits, no antifibrinolytics, and open cardiotomy with a combined strategy (HAC) that used heparin-coated circuits, ε-aminocaproic acid, and closed cardiotomy. Blood samples were drawn before, during, and after CPB for primary coronary bypass grafting surgery from 9 CTRL patients and 10 HAC patients. Thrombin-antithrombin complex and fibrinopeptide A levels (markers of thrombin and fibrin generation) were reduced in the HAC versus CTRL group after 30 min of CPB (P < 0.05). Average tissue plasminogen activator (tPA) levels were significantly lower in the HAC group by 30 min on CPB (P < 0.05), resulting in preservation of plasminogen activator inhibitor (PAI)-1 during CPB (P < 0.05). d-Dimer, a measure of intravascular fibrin formation and removal, was reduced in the HAC group during and after CPB (P < 0.005). Overall, the combined strategy was associated with a reduction in CPB-induced increases in markers of thrombin generation, fibrin formation, tPA release, and fibrin degradation and better preservation of PAI-1.

Blood Conservation Strategies in Pediatric Anesthesia

Management of bleeding in the neonate, infant, or child presents its own set of dilemmas and challenges. One of the primary problems is the lack of good scientific evidence regarding the best management strategies for children rather than for adults. The key to success in the predicament is firstly to ensure that the physician has a clear understanding of the underlying normal physiology of the young childs hematologic status. Then by adding knowledge of the abnormal pathology that is being presented, the physician can at least understand what anomalies he or she is facing. Once all the available information concerning the patients clinical condition and the options available has been well digested, a multidisciplinary approach allows the optimal use of all available resources. Good teamwork, understanding, and communication between all vested parties allows for a synergistic relationship to enhance patient care and give the best available end result.

Perioperative morbidity in children with elastin arteriopathy.

Children with elastin arteriopathy (EA), the majority of whom have Williams–Beuren syndrome, are at high risk for sudden death. Case reports suggest that the risk of perioperative cardiac arrest and death is high, but none have reported the frequency or risk factors for morbidity and mortality in an entire cohort of children with EA undergoing anesthesia.

Absent Aortocoronary Connections in a Neonate With Pulmonary Atresia and an Intact Ventricular Septum

m t i w t o f p M g p a a a I n o v m ( m t URING FETAL DEVELOPMENT, pulmonary atresia can cause important changes in the growth and function of he right ventricle (RV). If there is no ventricular septal defect ie, if the fetus has pulmonary atresia with an intact ventricular eptum [PA-IVS]), the RV becomes severely hypertrophic and he RV cavity develops into a small, high-pressure chamber.1-3 resumably, the high RV pressure promotes maintenance and rowth of RV to distal coronary artery communications (venriculocoronary arterial connections) and development of cornary abnormalities. Sometimes an “RV-dependent coronary irculation (RVDCC)” where major portions of the myocarium are perfused directly from the RV will be present. Most nfants with RVDCC, however, will also have antegrade cornary blood supply from the aorta, and staged surgical palliaion with or without RV decompression can be accomplished ith good results.4,5 This report describes the authors experince with a neonate with absent aortocoronary connections and hus a total RVDCC.

Anesthetic Considerations and Management of Transposition of the Great Arteries

Transposition of the great arteries was once an almost uniformly fatal disease in infancy. Six decades of advances in surgical techniques, intraoperative care, and perioperative management have led to at least 90% of patients reaching adulthood, most with a good quality of life. This review summarizes medical and surgical decision making during the neonatal perioperative period, with a special emphasis on factors pertinent to the anesthetic evaluation and care during primary surgical repair of transposition of the great arteries. A review is also provided of anesthetic considerations for noncardiac surgery later in childhood or adulthood, for those survivors of the arterial switch operation, Rastelli procedure, Nikaidoh procedure, and the réparation á l’étage ventriculaire procedure.

Perioperative and Anesthetic Considerations in Truncus Arteriosus

Truncus arteriosus is a congenital cardiac lesion in which failure of embryonic truncal septation results in a single semilunar valve and single arterial trunk providing both pulmonary and systemic circulations. Most patients with this lesion are symptomatic in the neonatal period with cyanosis and/or congestive heart failure and undergo complete repair in the first weeks of life. This review will focus on the anatomy, physiology, and perioperative anesthetic management of patients with truncus arteriosus.

The Response of Hemostatic Marker Levels to Activated Factor VII in a Neonate following Cardiopulmonary Bypass

The primary function of recombinant activated factor VII (rFVIIa) is to increase thrombin formation which leads to increased fibrin and less “bleeding.” As a result, most of literature utilizes “bleeding” as the outcome measure with respect to rFVIIa. However, we report the actual effect of rFVIIa on changes in hemostatic markers such as prothrombin activation peptide F1.2, thrombin antithrombin complex (TAT), D-dimer, tissue plasminogen activator (tPA), and plasminogen activator inhibitor (PAI) in a neonate after cardiopulmonary bypass. A single dose of rFVIIa caused a 5.5-fold increase in F1.2, 3.5-fold increase in TAT, and a small increase in d-dimer compared to only a 1.5-fold increase, no increase, and a decrease, respectively, in two neonates undergoing the same procedure having not received rFVIIa. The patterns of change for tPA and PAI were similar.