Early Patent Ductus Arteriosus Research Articles

Postoperative cardiorespiratory instability following ligation of the preterm ductus arteriosus is related to early need for intervention

To investigate the effect of postnatal age at patent ductus arteriosus (PDA) ligation on postoperative need for cardiotropic support. A significant proportion of premature infants with a hemodynamically significant ductus arteriosus (HSDA) require surgical intervention. The relationship of postnatal maturation to postoperative cardiorespiratory stability is poorly understood. All preterm neonates who underwent PDA ligation between October 2002 and September 2004 were identified and divided according to postnatal age at ductal ligation, into early (<or=4 weeks, n=29) and late (>4 weeks, n=36) groups. Neonatal birth demographics and morbidities, characteristics of the HSDA and reason for ligation were reviewed. Indices of cardiorespiratory stability (for example heart rate, mean arterial pressure) were recorded before and 1, 4, 8, 12 and 24 h following ligation. Details of perioperative cardiovascular interventions (for example crystalloid boluses, cardiotropic agents) were recorded. There were no differences in baseline neonatal demographics between the groups although a greater number of babies requiring early ligation had contraindication to indomethacin as the main reason for ligation. Early PDA ligation was associated with increased postoperative cardiotrope requirement (27.6 vs 5.6%, P=0.02) and decreased systolic blood pressure 8 h after intervention (P<0.05). Although increased oxygenation index was observed in both groups during the first 12 h it was only sustained to 24 h in the early group (P<0.05). Age at ligation remained a significant risk factor for postoperative cardiotrope requirement on multiple logistic regression analysis. Surgical ligation of the ductus arteriosus in preterm infants less than 28 days old is associated with oxygenation difficulties, decreased systolic arterial pressure and an increased need for cardiotropic support in the initial 24 postoperative hours. These data suggest the need to prospectively characterize perioperative cardiovascular physiology and identify predictive factors of clinical deterioration.

Anesthetic Management of Early Ligation of Patent Ductus Arteriosus for Premature Infants in the Neonatal Intensive Care Unit

Background: Left-to-right shunt through patent ductus arteriosus (PDA) produces significant hemodynamic and respiratory derangements in premature infants. Combined diseases in these patients often preclude attempts to close the PDA medically with indomethacin. Recently, the efficacy of early surgical closure performed in neonatal intensive care unit (NICU) rather than in operating room (OR) has been emphasized to reduce the risks of transferring unstable infants. Therefore, we reviewed the anesthetic management and clinical status of premature infants who underwent early surgical closure of PDA in NICU. Methods: Between 2001 and 2007, we reviewed retrospectively 17 premature infants with extremely low birth weight below 1,500 g and 33 weeks gestational age who underwent early ligation of PDA in NICU with left axillary minithoracotomy. Results: The mean gestational age and weight of infants were 29.4 ± 1.8 (26 +3 − 32) weeks and 849 ± 165 (450 − 1,080) g. Most of the infants had complications related to PDA and prematurity. Diastolic blood pressure and pulse oxymetry saturation changed with ligation of PDA from 27.4 ± 5.3 mmHg and 96.3 ± 2.9% to 38.1 ± 10.0 mmHg and 93.8 ± 2.6%, respectively. The body temperature didn’t show significant alterations. There was no direct procedure-related death although threeinfants died from pneumonia and sepsis at 29, 30 and 34 days postoperatively. Conclusions: Performing early PDA ligation in NICU was demonstrated to be safe and effective, especially in terms of providing continuous care and avoiding the risk of hypothermia. (Korean J Anesthesiol 2008; 54: 53∼7)

Indomethacin-induced early patent ductus arteriosus closure cannot be predicted by a decrease in pulse pressure.

Wide pulse pressure is considered to be a sign of patent ductus arteriosus (PDA). We tested the hypothesis that, following indomethacin therapy, PDA closure is associated with a significant decrease in pulse pressure. Thirty-two ventilated preterm infants were echocardiographically diagnosed within the first 24 hours of life with PDA. Systolic, diastolic, and mean arterial blood pressures were measured prior to indomethacin treatment and after echocardiographically confirmed PDA closure. Following PDA closure, systolic and diastolic blood pressures and mean arterial pressure increased significantly without a significant change of pulse pressure (17 +/- 7 to 20 +/- 12 torr). We conclude that in preterm infants with PDA, systolic, diastolic, and mean arterial blood pressures increase significantly within first few days of life. Pulse pressure does not appear to be affected by early PDA closure. We speculate that high pulmonary resistance in the first days of life prevents significant diastolic aortic runoff and leaves pulse pressure unaffected by PDA, as well as by its closure.

Early reopening and recanalization after successful coil occlusion of the patent ductus arteriosus

Background Controversy exists regarding early reopening and recanalization after successful (complete) coil occlusion of the patent ductus arteriosus (PDA). Methods Patients with successful PDA coil occlusion were reviewed with regard to PDA size and type, coil size, number of coils, and delivery technique. Follow-up echocardiograms at <24 hours, 6 months, and >12 months were reviewed for residual PDA shunt, left pulmonary artery (LPA) stenosis, and aortic obstruction. Results Successful coil occlusion was achieved in 94 patients. On the initial (<24 hours) echocardiogram, 76 of 92 (83%) had complete PDA occlusion, 5 of 92 (5%) had mild LPA stenosis, and no patient had aortic obstruction. Follow-up at 6 months was available in 70 patients, 57 with complete occlusion on the initial echocardiogram. PDA reopening was found in 3 of 57 patients (5%). Larger PDA diameter was associated with residual shunt (2.40 ± 0.40 mm versus 1.87 ± 0.53 mm; P <.01). Disagreement between the initial and 6-month echocardiogram was found in 11 of 70 patients (16%). Intermediate follow-up (median, 30 months; range, 12 months to 5.3 years) was available in 46 patients, 38 with complete occlusion on the 6-month echocardiogram. No patient (0 of 38) with a normal echocardiogram at 6 months developed recanalization, LPA stenosis, or aortic obstruction. Conclusion These data suggest that: (1) routine echocardiography immediately after PDA coil occlusion is unnecessary; (2) early PDA reopening is uncommon; and (3) PDA recanalization does not occur if complete echocardiographic closure is documented 6 months after coil occlusion. Additional follow-up examination in these patients may not be necessary. (Am Heart J 2002;143:889-93.)

The contractility and performance of the preterm left ventricle before and after early patent ductus arteriosus occlusion in surfactant-treated lambs.

The influence of left-right ductal shunting on early hemodynamic responses, namely left ventricular performance, contractility, and systemic perfusion was evaluated in nine preterm lambs (120 days gestational age) treated with surfactant. Blood gases were maintained in the physiological range using mechanical ventilation; hemodynamic and blood flow measurements (radionuclide labeled microspheres) were obtained before and after occlusion of the patent ductus arteriosus with a catheter balloon. The mean left-right ductal shunt before occlusion (1.2 h postnatal age) was 59 +/- 11% SD. Left ventricular output was increased in all lambs with PDA (pre: 306 +/- 106 versus post: 155 +/- 31 ml/min/kg; p less than 0.001); effective systemic blood flow and organ blood flows did not change. The left ventricle end-diastolic volume was increased in all and decreased following ductal occlusion (pre: 2.0 +/- 0.4 versus post: 1.5 +/- 0.2 ml/kg; p less than 0.01). Cardiac rate, ejection fraction, and contractility (peak dP/dt) did not change. Right-left ductal shunting was not detected in six similarly treated lambs. Thus, during the 1st h of life the hemodynamic profile of preterm lambs with patent ductus arteriosus was characterized by large magnitude left-right shunt and a "high" cardiac output state sufficient to maintain unchanged systemic perfusion. The increased left ventricle output was accomplished by increasing end-diastolic volume (Frank-Starling mechanism), but left ventricle contractility remained unchanged. We speculate that the preterm left ventricle may be unable to sustain the high level of pump performance and contractility required to compensate for the ductal "steal" of systemic blood flow.