Abstract 18701: Frequency and Contributing Factors to Diaphragm Paresis Following Pediatric Cardiac Surgery

Abstract

Introduction: Diaphragm paresis can occur as a complication of pediatric cardiac surgery that can prolong ventilation and length of ICU stay. Diaphragm plication (DP) may be necessary to improve respiratory mechanics and decrease duration of ventilation support. Early identification of patients who are likely to benefit from DP has not been studied. Methods: Patients at our institution diagnosed with diaphragm paresis between 2002 - 2012 were identified. Mode of diagnosis, demographics, operative procedures during index admission, and intervals of care were evaluated. Associations between predictors and DP were assessed by univariable and multivariable logistic regressions. Results: Diaphragm paresis was diagnosed in 161 patients following 6448 index surgeries, of whom 31 (19%) underwent DP (DP+). Paresis was diagnosed by ultrasound in 160 (99%) subjects at a median (IQR) time from surgery of 7 (3, 11) days in DP+ vs 10 (6, 19) days in DP- (p=0.02). DP was completed after a median (IQR) of 4 (1, 17) days after diagnosis. DP+ were younger in age [median (IQR) days DP+ 42 (14, 84) vs DP- 168 (28, 784); p<0.001], underwent surgery of higher RACHS-1 score [DP+ 3 (3, 4) vs DP- 3 (2, 4); p=0.02], and had a higher rate of hypothermic circulatory arrest [DP+ 14 (45%) vs DP- 23 (18%); p=0.001]. DP+ subjects had a rate of single ventricle physiology (32%), median sternotomy (94%), and bypass (87%) similar to DP- subjects. Only younger age (OR 1.003 per day, p=0.02) and use of hypothermic circulatory arrest (OR 3.06, p=0.01) remained significant on multivariable modeling. DP+ subjects had longer duration of ventilator support [DP+ 15 (9, 30) vs DP- 6.5 (3, 12.5) days; p<0.001] and ICU admission [DP+ 23 (18, 42) vs DP- 8 (5, 17) days; p<0.001]. However, ventilation was discontinued after a median of 1 (1,2) day after plication. The time interval from index surgery to diagnosis (EST 0.91, p<0.0001) and interval from diagnosis to DP (EST 0.94, p<0.0001; r2=0.91) were associated with a longer ICU stay even after adjusting for age and bypass time. Conclusion: Diaphragm paresis is common after congenital heart surgery. Earlier diagnosis and plication may shorten length of ventilation support and ICU stay, particularly in younger patients. Long-term outcome studies following DP are required.