David Mishali

The metabolic effects of fresh versus old stored blood in the priming of cardiopulmonary bypass solution for pediatric patients

OBJECTIVES Pediatric cardiopulmonary bypass involves the creation of a large obligatory priming reservoir. Packed red blood cells are an essential part of the cardiopulmonary bypass priming solution in children. The storage media in packed red blood cells might cause significant acid-base, glucose, and electrolyte imbalances, which have been associated with severe complications. The purpose of the present study was to evaluate the metabolic effects of fresh (< or =5 days) versus old (>5 days) stored packed red blood cells added to the priming solutions of pediatric patients undergoing cardiac surgery. METHODS Blood samples were drawn from cardiopulmonary bypass priming of 30 consecutive pediatric patients undergoing cardiac surgery. Patients were divided into 2 groups. Fresh (< or =5 days old) stored packed red blood cells were added to the priming solution in group 1, and old (>5 days old) stored packed red blood cells were added to the priming solution in group 2. In each group blood samples were drawn from the packed red blood cells on arrival to the operating room and from the priming solution immediately after packed red blood cells were added and after 20 minutes of prime circulation. Samples were also collected at the beginning of cardiopulmonary bypass and after 30 minutes. The last sample was collected on arrival to the pediatric intensive care unit. The levels of potassium, glucose, and lactate and the acid-base balance were analyzed in each sample. RESULTS There was a linear increase in potassium levels in packed red blood cell samples with increasing packed red blood cell age, ranging from 5.4 to 18.4 mEq/L. Significant differences in the concentrations of potassium, glucose, and lactate and the acid-base balance were found when comparing old and fresh packed red blood cells in samples taken during the packed red blood cell and early prime time. Those differences resolved after 20 minutes of reconstitution of the priming solution. The age of the packed red blood cells had no effect on the samples taken during bypass and those taken in the pediatric intensive care unit. CONCLUSION The significantly higher concentration of potassium and lactate and lower pH in old stored packed red blood cells has a minimal effect on the final constitution of priming solution before and during cardiopulmonary bypass in children undergoing corrective cardiac surgery.

Interleukin-8 secretion following cardiopulmonary bypass in children as a marker of early postoperative morbidity.

Background: Interleukin (IL)‐8, an 8 kDa peptide, is the first chemoattractant identified as being specific for neutrophils. Its possible association with early postoperative morbidity following cardiopulmonary bypass (CPB) in infants and children is unknown. This prospective cohort study sought possible roles of IL‐8 in the inflammatory response to CPB and investigated if changes in IL‐8 levels and clinical course and outcome were related.

Terlipressin for Children with Extremely Low Cardiac Output After Open Heart Surgery

Background: Terlipressin, a long-acting analog of vasopressin, has been used successfully in patients with extremely low cardiac output, but its application in children following open heart surgery is limited. Objective: To describe our experience using terlipressin in children with extremely low cardiac output after open heart surgery. Methods: Records were reviewed of all pediatric patients between January 2003 and December 2005 who had undergone open heart surgery, experienced extremely low cardiac output, and were treated with terlipressin as rescue therapy. Mean arterial blood pressure, heart rate, urine output, and lactate and oxygenation index values were retrieved and analyzed when available. Results: Twenty-nine children who were considered gravely ill despite conventional vasoactive agents received terlipressin as rescue therapy, which rapidly yielded significant improvements in all measured hemodynamic and respiratory indices. Mean ± SD arterial blood pressure increased significantly, from 49 ± 17 to 57 ± 16 mm Hg after 10 minutes (p = 0.004) and to 64 ± 15 mm Hg 24 hours after treatment onset (p = 0.001). Twenty-four hours following terlipressin administration, urine output increased from 1.5 ± 2.1 to 3.0 ± 2.3 mL/kg/h (p = 0.001), the oxygenation index decreased from 16.5 ± 27.9 to 9.5 ± 16.7 in the survivors (p = 0.023), and the inotropic score decreased from 41.9 ± 19.9 to 32.6 ± 18.8 (p = 0.009). Conclusions: Terlipressin caused significant improvement in hemodynamic, respiratory, and renal indices in children with extremely low cardiac output after open heart surgery. Further controlled studies are needed to confirm the drugs safety and efficacy in this population.

Micro-RNA-208a, -208b, and -499 as Biomarkers for Myocardial Damage After Cardiac Surgery in Children.

Objectives: To test the hypothesis that cardiac-enriched micro-RNAs can serve as accurate biomarkers that reflect myocardial injury and to predict the postoperative course following pediatric cardiac surgery. Micro-RNAs have emerged as plasma biomarkers for many pathologic states. We aimed to quantify preoperative and postoperative plasma levels of cardiac-enriched micro-RNA-208a, -208b, and -499 in children undergoing cardiac surgery and to evaluate correlations between their levels, the extent of myocardial damage, and the postoperative clinical course. Design: PICU. Patients: Thirty pediatric patients that underwent open heart surgery for the correction of congenital heart defects between January 2012 to July 2013. Interventions: None. Measurements and Main Results: At 12 hours post surgery, the plasma levels of the micro-RNAs increased by 300- to 4,000-fold. At 24 hours, their levels decreased but remained significantly higher than before surgery. Micro-RNA levels were associated with troponin levels, longer cardiopulmonary bypass and aortic crossclamp times, maximal postoperative aspartate aminotransferase levels, and delayed hospital discharge. Conclusions: Circulating micro-RNA-208a, -208b, and -499 are detectable in the plasma of children undergoing cardiac surgery and may serve as novel biomarkers for monitoring and forecasting postoperative myocardial injury and recovery.

Delta chemokine (fractalkine) – A novel mediator of pulmonary arterial hypertension in children undergoing cardiac surgery

BACKGROUND Fractalkine (FKN), a unique chemokine associated with pulmonary hypertension, may be involved in the acute stress response that regulates inflammation after cardiopulmonary bypass (CPB) surgery. We characterized FKN levels and correlated them with clinical parameters in children undergoing cardiac surgery involving CPB. METHODS Twenty-seven consecutive patients, aged 30 days to 11.5 years, who underwent surgery for correction of congenital heart defects, were prospectively studied. Serial blood samples were collected preoperatively, upon termination of CPB, and at six points postoperatively. Plasma was recovered immediately, aliquoted, and frozen at -70° C until assayed. Clinical and laboratory data were collected. RESULTS Baseline FKN levels were skewed between patients. Patients with low FKN levels showed significantly higher levels of oxygen saturation in room air compared to patients with high FKN levels (p<0.05). Moreover, there was a positive correlation between preoperative pulmonary arterial hypertension and FKN levels (p<0.05). Surprisingly, FKN elevation from preoperative to postoperative levels displayed no discernible pattern. CONCLUSIONS FKN levels significantly correlate with preoperative hypoxemia and PAH, suggesting that FKN may be up-regulated during hypoxemia. CPB is not associated with acute changes in circulating FKN levels. The role of FKN in the postoperative course should be further investigated.

The Utilization of an Insertable Cardiac Monitor in a Child With Pallid Breath-Holding Spells

BACKGROUND Pacing can be a successful treatment for pallid breath-holding spells, primarily in individuals with severe bradycardia. PATIENT DESCRIPTION We describe an 18-month-old girl experiencing severe pallid breath-holding spells in whom repeated electrocardiographic, Holter, and electroencephalographic monitoring tests were all normal. RESULTS Using a subcutaneous insertable cardiac monitor, severe bradycardia was detected during one of this girls episodes. This finding led to a pacemaker implantation. Subsequently, her breath-holding spells completely resolved. CONCLUSION This child illustrates the ability of the insertable cardiac monitor to help and diagnose arrhythmias in children with unresolved clinical findings. The ability to implant it with a minimal scar makes it ideal for uncooperative individuals with relative few and unexpected episodes that are hard to diagnose.