Intraoperative Hemodynamic Collapse During Patent Ductus Arteriosus Ligation in an Extremely Low Birth Weight Infant: A Case Report

Background: and Clinical Significant: Patent ductus arteriosus (PDA) is a common car-diovascular disorder in extremely low birth weight(ELBW) infants, for which surgical ligation is indicated when pharmacologic closure fails. Sudden increases in afterload combined with immature myocardial contractility can lead to post-ligation cardiac syn-drome, which usually occurs within hours after surgery. However, acute intraoperative hemodynamic collapse during PDA ligation has rarely been described. Case Presenta-tion: A preterm infant born at 24 weeks and 3 days of gestation with a birth weight of 890 g underwent emergency PDA ligation for a hemodynamically significant PDA refractory to pharmacological treatment. Fifteen minutes after skin incision, the infant developed severe hypoxemia, bradycardia, and non-measurable noninvasive blood pressure, which required immediate hemodynamic resuscitation with manual ventilation, fluid admin-istration, and dopamine and dobutamine infusions. Hemodynamics gradually recovered after completion of ductal ligation, whereas hypoxemia persisted. Postoperative chest radiography revealed a left-sided pneumothorax, and oxygen saturation stabilized after pleural air aspiration. The subsequent clinical course was uneventful, and typical post-ligation cardiac syndrome did not develop. Conclusions: This case suggests that intraoperative hemodynamic collapse during PDA ligation may share pathophysiologic features with post-ligation cardiac syndrome, and that concomitant pneumothorax can further aggravate hemodynamic instability by worsening hypoxemia and reducing venous return.