ICU: T3 therapy after congenital heart surgery

Circulation. 2010;122:S224-S233

Triiodothyronine Supplementation in Infants and Children Undergoing Cardiopulmonary Bypass (TRICC)
A Multicenter Placebo-Controlled Randomized Trial: Age Analysis

Michael A. Portman, MD; April Slee, MS; Aaron K. Olson, MD; Gordon Cohen, MD, PhD; Tom Karl, MD; Elizabeth Tong, PhD; Laura Hastings, MD; Hitendra Patel, MD; Olaf Reinhartz, MD; Antonio R. Mott, MD; Richard Mainwaring, MD; Justin Linam, MA; Sara Danzi, PhD, for the TRICC Investigators

Background—Triiodothyronine levels decrease in infants and children after cardiopulmonary bypass. We tested the primary hypothesis that triiodothyronine (T3) repletion is safe in this population and produces improvements in postoperative clinical outcome.

Methods and Results—The TRICC study was a prospective, multicenter, double-blind, randomized, placebo-controlled trial in children younger than 2 years old undergoing heart surgery with cardiopulmonary bypass. Enrollment was stratified by surgical diagnosis. Time to extubation (TTE) was the primary outcome. Patients received intravenous T3 as Triostat (n=98) or placebo (n=95), and data were analyzed using Cox proportional hazards. Overall, TTE was similar between groups. There were no differences in adverse event rates, including arrhythmia. Prespecified analyses showed a significant interaction between age and treatment (P=0.0012). For patients younger than 5 months, the hazard ratio (chance of extubation) for Triostat was 1.72. (P=0.0216). Placebo median TTE was 98 hours with 95% confidence interval (CI) of 71 to 142 compared to Triostat TTE at 55 hours with CI of 44 to 92. TTE shortening corresponded to a reduction in inotropic agent use and improvement in cardiac function. For children 5 months of age, or older, Triostat produced a significant delay in median TTE: 16 hours (CI, 7–22) for placebo and 20 hours (CI, 16–45) for Triostat and (hazard ratio, 0.60; P=0.0220).

Conclusions—T3 supplementation is safe. Analyses using age stratification indicate that T3 supplementation provides clinical advantages in patients younger than 5 months and no benefit for those older than 5 months.

Interventional Catheterization Performed in the Early Postoperative Period After Congenital Heart Surgery in Children

JACC 2004;43:1264-9

Evan Zahn et al.

1995-2001.

62 patients underwent 66 catheterizations.

Median postop day 9 (0-42 days).

35 cases involved 50 interventions.

Median age 4 mo (2 days - 11 years)

Median weight 4.7 kg (2.3 - 45 kg)

Success rate:

Angioplasty 100%

Stent implantation 87%

Vascular/Septal occlusion 100%

Palliative pulmonary valvotomy 75%

30 procedures were Angioplasty or Stent placement. 26 of these were at recent suture lines.

Complications: Stent migration 1, CVA 1, LPA stenosis 1

30-day survival: 83% (No procedure related mortality)

LPA stenosis - stent:
BT shunt occlusion - balloon:
Notable comments in the article:

1) Balloon/Stenosis ratio - 2.5 (range 1.4 - 4.4)...similar to ratio used in Rosales et al. 2002 study (Cath Cardiovasc Interv 2002;56:272-7). Therefore, reason for 20% mortality from vessel disruption may be due to intrinsic difference in technique.

2) ...A variety of freshly sutured materials can undergo angioplasty and stent placement without vessel disruption.

Potential reasons:

a. Prolene sutures - elongates as much as 34% before breaking

b. An enlargement of the circumference of the suture line (increased distance between parallel throws) in response to balloon inflation - prevents suture breakage....we believe continuous prolene suture lines can be safely and effectively expanded with balloon/stenosis ratios of 2.5 or less...since angioplasty needs higher ratio, stent placement is preferable in early postop period.

Delayed Sternal Closure

J Thorac Cardiovasc Surg 1997;113:886-893

DELAYED STERNAL CLOSURE AFTER CARDIAC OPERATIONS IN A PEDIATRIC POPULATION

S. Tabbutt, MD, PhD, B. W. Duncan, MD, D. McLaughlin, RN, D. L. Wessel, MD, R. A. Jonas, MD, P. C. Laussen, MB, BS

Objective: The purpose of this study was to assess morbidity and mortality associated with delayed sternal closure after pediatric cardiac operations. Methods: Hospital records were reviewed of all patients with an open sternum after a cardiac operation at Children's Hospital, Boston, from January 1992 to December 1995. Results: A total of 178 patients had delayed sternal closure with an overall mortality rate of 19%. The most common diagnosis of patients with delayed sternal closure was hypoplastic left heart syndrome (29%). Although myocardial distention or chest wall edema (n = 47) was a common indication to delay sternal closure, in many patients (n = 47) the sternum was left open electively to avoid postoperative cardiac or respiratory compromise. Successful sternal closure was achieved in 158 patients (89%) at a mean of 3.4 ± 1.8 days after opening. There were significant increases in left atrial pressure (7.7 ± 3.4 to 9.8 ± 4.1 mm Hg, p = 0.00001) and right atrial pressure (8 ± 3.2 to 10.1 ± 3.3 mm Hg, p = 0.00001) with sternal closure. There was a small but statistically significant drop in pH (7.44 ± 0.05 to 7.41 ± 0.08, p < 0.0001) during sternal closure. The peak inspiratory pressure, delivered breaths per minute, and fraction of inspired oxygen all significantly increased during sternal closure. Clinical evidence of surgical site infection occurred in 12 (6.7%) of the patients with delayed sternal closure; mediastinitis developed in 7 (3.9%) patients. Conclusions: Although delayed sternal closure after complex operations for congenital heart disease is often necessary in the operating room because of edema, unstable hemodynamic conditions, or bleeding, it can also be used electively to aid in hemodynamic and respiratory stability in the initial postoperative period. Our review supports a low morbidity associated with delayed sternal closure in a pediatric population.

Delayed Sternal Closure is life-saving:

Children - European Journal of Cardio-thoracic Surgery 2002;21(5):787-93

Adult - Annals of Thoracic and Cardiovascular Surgery 2002;8:220-3

Nursing Consideration in Delayed Sternal Closure in Children: Critical Care Nurse June 2010;30:50-61.

Decrease in rSO2 (cerebral & somatic) after Delayed Sternal Closure - JTCVS Apr 2010;139:894-900