Excessive Postoperative Bleeding and Outcomes in Neonates Undergoing Cardiopulmonary Bypass

Abstract

T he effects of dexmedetomidine premedication on the minimum alveolar concentration of sevoflurane for tracheal intubation (MAC TI ) in children was investigated in a prospective, randomized, clinical comparison study in the operating room of an academic hospital in 90 pediatric, American Society of Anesthesiologists physical status I patients, aged 3 to 7 years. The patients, who were scheduled for minor surgery, were randomized into 3 groups who received placebo, dexmedetomidine 1 μg/kg or dexmedetomidine 2 μg/kg approximately 60 minutes before anesthesia. Anesthesia was induced with sevoflurane. Each concentration of sevoflurane for which a tracheal intubation was attempted was predetermined based on modification of the Dixon's up-and-down method, with 0.25% as a step size and held constant for at least 15 minutes before tracheal intubation. All responses ("movement" or "no movement") to tracheal intubation were evaluated. The MAC TI (mean ± SD) values of sevoflurane were 2.82% ± 0.17% in the control group, 2.26% ± 0.18% in the 1 μg/kg dexmedetomidine group, and 1.83% ± 0.16% in the 2 μg/kg dexmedetomidine group. Dexmedetomidine premedication (1 and 2 μg/kg) decreased the MAC TI by 20% and 35%, respectively. No clinically important episodes of hypotension or bradycardia occurred in any patient. Intranasal dexmedetomidine premedication results in a dose-dependent decrease in the concentration of sevoflurane required for tracheal intubation of children. COMMENTThis article by Yao et al examines the effects of intranasal dexmedetomidine premedication on tracheal intubation conditions during standard state sevoflurane anesthesia. Ninety pediatric patients aged 3 to 7 years were randomized into 3 groups (placebo, 1 μg/kg, and 2 μg/kg) intranasal dexmedetomidine or placebo administered 60 minutes before inhalation induction. After inhalational induction, the end-tidal sevoflurane concentration was held constant for 15 minutes to allow for adequate equilibrium with the brain concentration. The minimal alveolar concentration of sevoflurane for tracheal intubation (MAC TI ) was calculated using Dixon's up-and-down method and found to be 2.82% for placebo, 2.26% for 1 μg/kg dexmedetomidine, and 1.83% for 2 μg/kg dexmedetomidine, showing that intranasal dexmedetomidine reduces the minimum alveolar concentration in a dose-dependent manner by 20% and 35%, respectively.Although this is the first report about the effects of intranasal dexmedetomidine on MAC TI , the study results are consistent with previous investigations showing that the α-2 agonist clonidine reduces anesthetic requirements.N eonates undergoing congenital cardiac surgery requiring cardiopulmonary bypass (CPB) are at a high risk of postoperative bleeding for reasons including immature coagulation, long CPB times, hemodilution from the CPB circuit priming volumes, and cardiac repairs performed at low temperatures. There is also increased morbidity associated with blood transfusions that are commonly used to treat postoperative bleeding. This study observed t...

Rotational Thromboelastometry Rapidly Predicts Thrombocytopenia and Hypofibrinogenemia During Neonatal Cardiopulmonary Bypass

“…Perioperative bleeding following cardiopulmonary bypass (CPB) is associated with significant morbidity and mortality. 1,2 Compared to older children and adults, neonates have an increased risk of bleeding during and after CPB. 3 –5 Excessive bleeding after neonatal cardiac surgery has been linked to increased need for postoperative dialysis, extracorporeal membrane oxygenation, cardiac intensive care unit length of stay, and mortality.…”

Perioperative blood product transfusion of two different perfusion strategies on pediatric patients undergoing aortic arch surgery

“…A negative correlation between platelet transfusion and CMP suggested that pediatric patients under CMP have a lower intraoperative demand for platelet products. According to Guzzetta et al, 31 long CPB time and serious coagulation damage both contribute to more postoperative chest tube drainage and delayed extubation. In this study, we found that CPB time was positively correlated with delayed extubation rate.…”

Peptide Mimetic Drugs for Modulating Thrombosis and Hemostasis

“…Given the promising developments of peptide mimetic drugs for regulating hemostasis and thrombosis, these drugs could prove to be attractive targets for the application of novel therapeutics in emerging markets. One such an example is the treatment of postoperative bleeding in neonatal populations [Guzzetta et al, ]. Mitigating postoperative bleeding is currently addressed through transfusion of adult blood products, including platelets and cryoprecipitate (fibrinogen component) [Brown et al, ].…”