Predicting Heparin Responsiveness in Children Before Cardiopulmonary Bypass: A Retrospective Cohort Study.

BACKGROUND: Inadequate or excess administration of unfractionated heparin for cardiopulmonary bypass (CPB) can cause significant harm. Age-dependent differences in the pharmacodynamics and pharmacokinetics of heparin contribute to increased variability of heparin responsiveness in children. The aims of the current study were to (1) examine the correlation between predicted and observed heparin responsiveness in children before CPB measured using the Hemostasis Management System (HMS) Plus (Medtronic, Minneapolis, MN), (2) describe age-specific reference intervals for heparin sensitivity index (HSI) observed in children, and (3) test predictive models of HSI using preoperative clinical and laboratory data. METHODS: In this retrospective cohort study, children (ages ≤17 years) who required therapeutic heparinization for CPB in a 40-month period between September 2010 and December 2013 were investigated. Children weighing ≥45 kg or with a height ≥142 cm were excluded. HSI was defined as the difference between activated clotting time after heparin administration and the baseline activated clotting time divided by the heparin-loading dose (IU) per kilogram. Lin's concordance correlation coefficient was used for the primary analysis of the relationship between predicted and observed HSI. Reference intervals were calculated for HSI using medians and 2.5% and 97.5% percentiles according to established guidelines for clinical and laboratory standards. Nonparametric regression analyses were used to model the relationship between HSI (dependent variable) and preoperative covariates (independent variables). RESULTS: A total of 1281 eligible children were included in the final analysis. Overall, there was a moderate correlation between predicted and observed HSI measured using HMS Plus System (rho_c = 0.46; 95% confidence interval, 0.41-0.50; P < .001). Sixty-five percent (829 of 1281) of predicted HSI values were less than observed. From adjusted regression models, HSI was best predicted by preoperative international normalized ratio, platelet count, and weight, but this model accounted for only 25% of the variance in HSI. CONCLUSIONS: In a large cohort of children, heparin responsiveness before CPB was not reliably predicted by either in vitro measurement using the HMS Plus System or commonly available preoperative clinical and laboratory data. We describe age-specific reference intervals for HSI in children, and we anticipate that these data will aid the identification of heparin resistance in this population.

Impact of a quality improvement initiative with a dedicated anesthesia team on outcomes after surgery for adult congenital heart disease.

Objectives: A quality improvement initiative was introduced to the adult congenital cardiac surgery program at Toronto General Hospital in January 2016. A dedicated Adult Congenital Anesthesia and intensive care unit team was introduced within the cardiac group. The use of factor concentrates was introduced. The study compares perioperative mortality, adverse events, and transfusion burden before and after this process change. Methods: We performed a retrospective analysis of all adult congenital cardiac surgeries from January 2004 to July 2019. Two groups were analyzed: patients undergoing operation before and after 2016. The primary outcome was in-hospital mortality. One-year mortality and prevalence of key morbidities were analyzed as secondary outcomes. A separate analysis looked at patients who had and had not attended an anesthesia-led preassessment clinic. Results: In-hospital mortality was significantly reduced in patients undergoing operation after 2016 (1.1% vs 4.3%, P = .003) despite a higher risk profile. One-year mortality (1.3% vs 5.8%, P = .003) and ventilation times (5.5 hours [3.4-13.0] vs 6.3 hours [4.2-16.2], P = .001) were also reduced. The incidence of stroke and renal failure was similar between groups. Blood product exposure was comparable, but the incidence of chest reopening decreased (1.8% vs 4.8%, P = .022), despite more patients with multiple previous chest wall incisions, on anticoagulation, and with more complex cardiac anatomy. There were no significant outcome differences between those who did or did not attend the preassessment clinic. Conclusions: Both in-hospital and 1-year mortality were significantly reduced after the introduction of a quality improvement program, despite a higher risk profile. Blood product exposure remained unchanged, but there were less chest reopenings.

Novel Leg Cannula for Venous Decompression in Peripheral Extracorporeal Membrane Oxygenation.

A chimney femoral artery graft for peripheral extracorporeal membrane oxygenation can potentially cause hyperperfusion and subsequent venous congestion in the ipsilateral leg, especially in the context of septic shock and higher flow requirement. This report describes a novel technique to use an additional leg venous cannula to avoid leg congestion as well as to achieve higher total flow.

Clinical benefits of methylprednisolone in off-pump coronary artery bypass surgery.

BACKGROUND: It has not been established whether off-pump coronary artery bypass grafting (OPCABG) is less invasive than conventional CABG. In our experience, OPCABG has several advantages such as shorter operative duration, decreased requirement of blood transfusion and myocardial protection compared with conventional CABG. However, frequency of postoperative paroxysmal atrial fibrillation (PAF) is similar between these techniques and early postoperative C-reactive protein (CRP) levels have been shown to be significantly higher in OPCABG. We hypothesized that preoperative steroid administration, routinely used only in conventional CABG, may alleviate high postoperative PAF and CRP levels. Therefore, a prospective, double-blind, clinical trial was conducted in OPCABG patients to investigate the clinical effects of preoperative steroid administration. METHODS: Thirty OPCABG patients were randomly divided into 2 groups: control (Group C: n = 15) and methylprednisolone (Group M: n = 15) groups. Group M patients were intravenously administered 1000 mg methylprednisolone during anesthesia induction. RESULTS: Hospital death and infectious complication such as mediastinitis were not observed in either group. Postoperative PAF occurred in 47 % (7/15) of patients in group C but in only 1 patient in group M (7 %, P = 0.013). Early postoperative CRP levels were significantly lower in group M than in group C (peak values on postoperative day 2: group M 15 ± 6 mg/dL vs. group C 23 ± 4 mg/dL; P = 0.0002). CONCLUSIONS: Preoperative steroid administration in OPCABG patients significantly suppresses CRP elevation and prevents postoperative PAF without increasing in-hospital mortality or infectious complications.