Randall S. Fortuna

Medication Adsorption into Contemporary Extracorporeal Membrane Oxygenator Circuits

OBJECTIVE This study was conducted to evaluate the amount of medication adsorbed into extracorporeal membrane oxygenation (ECMO) circuits with a polymethylpentane membrane oxygenator and heparin-coated polyvinyl chloride tubing. METHODS An ECMO circuit with the aforementioned components was set up ex vivo and primed with expired blood. Midazolam, lorazepam, morphine, and fentanyl were administered to the circuit. Fifteen minutes after medication administration, 60 mL of blood were removed and stored in a 60-mL syringe to serve as a control. Medication levels were drawn from the ECMO circuit (test) and control syringe (control) 15 minutes, 24 hours, and 48 hours after the medications were administered. ECMO circuit medication levels were compared to their corresponding syringe control medication levels. Descriptive statistics were used to determine the percentage of medication remaining in the blood and compare it to the control value. RESULTS Except for morphine, there was a large decline in medication levels over the 48-hour period. Compared to control values, 17.2% of midazolam, 41.3% of lorazepam, 32.6% of fentanyl, and 102% of morphine remained in the ECMO circuit. CONCLUSION Despite the use of newer components in ECMO circuits, a large quantity of medication is adsorbed into the ECMO circuit. Midazolam, lorazepam, and fentanyl all showed reductions in medication levels greater than 50%. Morphine may have advantages for patients on ECMO, as its concentration does not appear to be affected.

Pulse oximeter accuracy and precision affected by sensor location in cyanotic children.

Objective: Children’s digits are often too small for proper attachment of oximeter sensors, necessitating sensor placement on the sole of the foot or palm of the hand. No study has determined what effect these sensor locations have on the accuracy and precision of this technology. The objective of this study was to assess the effect of sensor location on pulse oximeter accuracy (i.e., bias) and precision in critically ill children. Design: Prospective, observational study with consecutive sampling. Setting: Tertiary care, pediatric intensive care unit. Patients: Fifty critically ill children, newborn to 2 yrs of age, with an indwelling arterial catheter. Forty-seven of 50 (94%) patients were postcardiac surgery. Interventions: None. Measurements and Main Results: Co-oximeter-measured arterial oxygen saturation (Sao2) was compared with simultaneously obtained pulse oximetry saturations (Spo2). A total of 98 measurements were obtained, 48 measurements in the upper extremities (finger and palm) and 50 measurements in the lower extremities (toe and sole). The median Sao2 was 92% (66% to 100%). There was a significant difference in bias (i.e., average Spo2 − Sao2) and precision (±1 sd) when the sole and toe were compared (sole, 2.9 ± 3.9 vs. toe, 1.6 ± 2.2, p = .02) but no significant difference in bias and precision between the palm and the finger (palm, 1.4 ± 3.2 vs. finger, 1.2 ± 2.3, p = .99). There was a significant difference in bias ± precision when the Sao2 was <90% compared with when Sao2 was ≥90% in the sole (6.0 ± 5.7 vs. 1.8 ± 2.1, p = .002) and palm (4.5 ± 4.5 vs. 0.7 ± 2.4, p = .006) but no significant difference in the finger (1.8 ± 3.8 vs. 1.1 ± 1.8, p = .95) or toe (1.9 ± 2.9 vs. 1.6 ± 1.9, p = .65). Conclusions: The Philips M1020A pulse oximeter and Nellcor MAX-N sensors were less accurate and precise when used on the sole of the foot or palm of the hand of a child with an Sao2 <90%.

The Ross-Konno Is a High-Risk Procedure When Compared With the Ross Operation in Children

BACKGROUND For children who require aortic valve replacement, the pulmonary autograft (Ross procedure) may be the ideal substitute. However, performing a modified Konno procedure at the time of autograft implantation (Ross-Konno) may be associated with significant morbidity and mortality. A retrospective study was undertaken to compare the outcomes of Ross-Konno (RK) and the Ross (R) procedures including the need for reinterventions and long-term survival. METHODS Between 1993 and 2011, 78 children (mean age, 11.1 ± 5.6 years; range, 1 week to 18 years) underwent the Ross procedure. Modified Konno-type enlargement of the left ventricular outflow tract was performed in 18 of those patients. RESULTS There was no statistically significant difference between the groups with respect to pathologic process, sex, concomitant procedures, and aortic gradient. Our data demonstrate that mean age (R, 12.9 years versus RK, 5.3 years; p < 0.001), mean size of allograft (R, 23.3 mm versus RK, 20.1 mm; p < 0.001), previous surgery (R, 51% versus RK, 83%; p = 0.05), and postoperative morbidity (R, 3% versus RK, 28%; p = 0.003) were significantly different between the groups. There were 3 hospital deaths (all RK with mitral valve anomalies). Actuarial survival at 10 years was significantly better for Ross patients than Ross-Konno (R, 96% versus RK, 72%; p = 0.001). Freedom from autograft, right ventricular outflow tract obstruction, and cumulative reoperations at 10 years were not significantly different between groups. CONCLUSIONS The risk of death and postoperative complications after the Ross-Konno procedure is higher than for the Ross procedure. Preoperative complexity (including mitral valve anomalies) is associated with significantly higher morbidity and mortality. Autograft insufficiency and right ventricular outflow tract obstruction are common postoperative complications, requiring reoperation in one quarter of patients, but these were not significantly different between the groups.

Autograft or Allograft Aortic Root Replacement in Children and Young Adults With Aortic Valve Disease: A Single-Center Comparison

BACKGROUND We analyzed the outcome of children and young adults (younger than 40 years) with aortic valve disease who underwent allograft or autograft aortic root replacement (ARR) in our institution and evaluated whether there is a preference for either valve substitute. METHODS One-hundred fifty patients younger than 40 years underwent ARR between January 1990 and July 2011. Forty-four patients, aged 18.8 ± 12.4 years, had ARR with allograft conduit (allograft group), whereas 106 patients, aged 17.9 ± 11 years (p = 0.63), had a Ross ARR during the same period of time (autograft group). Echocardiographic data were reviewed to evaluate valve performance. The 2 groups were similar with respect to age, gender, etiology, and previous and concomitant procedures. RESULTS Operative deaths were 3 in the autograft group. There were 6 late deaths in the autograft group and 5 in the allograft group. Survival was 92% and 84% at 5 and 15 years, respectively, in the allograft group versus 93% and 91% in the autograft group (p = 0.42). Freedom from any type of reintervention and from reoperation on aortic valve were similar (autograft, 64% and 72% versus allograft, 66% and 66%; p = not significant) at 15 years. Freedom from explantation were significantly better for Ross patients (autograft, 82% versus allograft, 66%; p = 0.05). CONCLUSIONS Aortic valve replacement with either the autograft or allograft provides good clinical results in children and young adults during an intermediate duration of observation. Survival early after ARR does not differ depending on the type of prosthesis. In patients with aortic valve disease, autograft and allograft ARR show comparable satisfactory early and long-term results, with the increasing reoperation risk in the second decade after operation remaining a major concern.

Failed Autograft After the Ross Procedure in Children: Management and Outcome

BACKGROUND Autograft dilatation (AD) and aortic insufficiency (AI) after the Ross procedure are the most common causes of late autograft failure. The purpose of this study was to examine the results of valve-sparing root replacement (modified David) and composite root replacement. METHODS We performed a retrospective review of all children (n=78) undergoing a Ross procedure at our Center from 1993 to 2011. RESULTS Median follow-up was 10 years (1to 18 years). Freedom from autograft reoperation was 94% at 5 years, and 65% at 15 years. Freedom from greater than 2+ autograft AI was 93% at 5 years and 76% at 15 years. Autograft reoperation was necessary in 22 patients, at a median interval of 8.7 years after the original procedure. Indications for reoperation were AI with autograft dilatation in 15 patients, AI without dilatation in 2 patients, and AD without AI in 5 patients. Surgical procedures used at reoperation included valve-sparing root replacement in 14 patients, root replacement either mechanical or biologic valved conduit in 6 patients, and valve replacement in 2 patients. At a mean follow-up of 5.8 years after reoperation, 4 patients from the valve-sparing group underwent second reoperation (valve replacement). Freedom from second autograft reoperation was 71% for patients after a valve sparing procedure and 100% for patients after an aortic valve or root replacement (Bentall procedure) at 5 years. CONCLUSIONS Autograft valve-sparing root replacement and composite aortic root replacement are effective treatments for aortic root dilation and AI after the Ross procedure. The potential of late autograft insufficiency after valve-sparing root replacement warrants annual follow-up.

Pediatric Extracorporeal Membrane Oxygenation: An Introduction for Emergency Medicine Physicians

BACKGROUND Extracorporeal membrane oxygenation (ECMO) therapy has supported critically ill pediatric patients in the intensive care unit setting with cardiac and respiratory failure. This therapy is beginning to transition to the emergency department setting. OBJECTIVE OF REVIEW This article describes the fundamentals of ECMO and familiarizes the emergency medicine physician with its use in critically ill pediatric patients. DISCUSSION ECMO can be utilized as either venoarterial (VA) or venovenous (VV), to support oxygenation and perfusion in respiratory failure, sepsis, cardiac arrest, and environmental hypothermia.

Outcomes of Double Inlet Left Ventricle and Similar Morphologies: A Single Center Comparison of Initial Pulmonary Artery Banding Versus a Norwood‐Type Reconstruction

Patients with double inlet left ventricle (DILV)/transposition and similar morphologies have their systemic outflow traverse a bulboventricular foramen (BVF), which has a propensity to narrow over time. The aim of this study is to evaluate the outcomes of initial pulmonary artery banding (PAB) compared with the Norwood‐type reconstruction in neonates.

Outcomes of Tricuspid Valve Repair in Children with Hypoplastic Left Heart Syndrome

Tricuspid valve regurgitation (TR) is a common finding in children with hypoplastic left heart syndrome (HLHS) undergoing staged surgical reconstruction and can result from either abnormal valve morphology or incomplete leaflet coaptation due to annular dilatation. The purpose of this study was to determine the incidence of severe TR and to evaluate the effect of surgically treated tricuspid valve (TV) disease on overall survival.