Preliminary study: Changes in systolic volume index during Nuss surgery.

Introduction: The surgical correction of the pectus excavatum (PE) is justified by the progressive cardiopulmonary involvement. There are few studies that analyze the hemodynamic changes during the intraoperative period.

Objectives: To describe the stroke volume index (SVI) changes during the intraoperative with the Nuss technique, through the monitoring of the invasive blood pressure curve (IAP).

Material and methods: A prospective observational study of pediatric patients undergoing Nuss surgery by right video-assisted thoracoscopy (VATS). By analyzing the IAP curve using the FloTrac monitor (Edwars®), the following dynamic parameters were evaluated: stroke volume index (SVI), cardiac index (CI), stroke volume variation (SVV). The dates were collected on 3 occasions: baseline, before bar placement (after preload optimization in search of the target IVS) and after bar placement.

Results: Were included 6 patients aged 14-16 years, 5/6 males. Five of six had cardiac MRI with decreased FEVD (33%-44%), 1/6 with FEVD 53%. At baseline, IVS and CI were decreased, 19-29 ml/lat/m² and 1.1-1.9 L/min/m². Two-Three overloads of volume were performed to reach target IVS (25-35 ml/lat/m²), with an increase of 0%-75%. After the placement of the bar, the IVS was increased by 8%-42% (35-40 ml/lat/m²) with respect to the target IVS, with normalization of the CI (2.5-3.5 L/min/m²).

Conclusions: PE produces compression of the VD, with descent of the IVS. After the placement of the Nuss bar, through the analysis of the IAP, we can objectifield an increase in the IVS and normalization of the CI.