No abstract

To investigate the relationship between maternal exercise and fetal circulatory responses in humans during the third trimester of pregnancy, changes in uterine, umbilical and fetal cerebral circulations were measured by pulsed-Doppler ultrasound method in 14 healthy volunteer pregnant women before and just after a moderate non-exhaustive exercise. Maternal heart rate increased significantly reaching 80% of the theoretical maximal heart rate (TMHR) while uterine resistance indices did not change. The fetal heart rate and umbilical mean velocity were unchanged while umbilical resistance index decreased slightly (0.58 +/- 0.06 versus 0.62 +/- 0.07, P < 0.05). The fetal internal carotid artery mean velocity increased (23.2 +/- 5.3 versus 20.4 +/- 4.1 cm/s, P < 0.02) and the cerebral resistance index decreased (0.71 +/- 0.11 versus 0.80 +/- 0.10, P < 0.01). We conclude that submaximal maternal exercise at 80% of TMHR does not significantly alter uterine perfusion but involves a slight fetal cerebral vasodilation which could be due to a moderate fetal hemoglobin desaturation.

Circulatory failure following cardiac arrest (CA) requires catecholamine support and occasionally veno-arterial extracorporeal membrane oxygenation (vaECMO). VaECMO-generated blood flow is continuous and retrograde, increasing ventricular stroke work. Our aim was to assess the benefit of a device generating a pulsatile vaECMO flow synchronized with the heart rhythm lowering systolic vaECMO output on the left ventricular ejection fraction (LVEF) and pulmonary capillary pressure (Pcap) after CA. This experimental randomized study in pigs compared standard nonpulsatile vaECMO (control) with pulsatile synchronized vaECMO (study) group using a pulsatility-generating device. After sedation and intubation, ventricular fibrillation was induced by pacing. After 10-min ventricular fibrillation, cardiopulmonary resuscitation was performed for 20 min then vaECMO, defibrillation and 0.15 µg/kg/min intravenous epinephrine infusion were initiated. Hemodynamics, Pcap, LVEF by echocardiography and angiography were measured at baseline and every 30 min after the vaECMO start until vaECMO and epinephrine were stopped (at 120 min), and 30 min later. Baseline hemodynamics did not differ between groups; 120 min after vaECMO initiation, LVEF by echocardiography and angiography was significantly higher in the study than control group 55 ± 19% versus 34 ± 13% (P = 0.042), 50 ± 16% versus 33 ± 12% (P = 0.043), respectively. Pcap decreased from baseline by 4.2 ± 8.6 mm Hg in the study group but increased by 5.6 ± 5.9 mm Hg in the control group (P = 0.043). Thirty minutes later, LVEF remained higher in the study group 44 ± 7% versus 26 ± 11% (P = 0.008) while Pcap did not differ. A synchronized pulsatile device decreasing systolic output from vaECMO improved LVEF and Pcap in a pig model of CA and resuscitation.

ABSTRACT.Purpose: Determine the effect of repeated intravitreal injections of ranibizumab (0.5 mg; 0.05 ml) on retrobulbar blood flow velocities (BFVs) using ultrasound imaging quantification in twenty patients with exudative age-related macular degeneration treated for 6 months. Methods: Visualacuity(ETDRS),centralmacularthickness(OCT),peak-systolic, end-diastolic and mean-BFVs in central retinal (CRA), temporal posterior ciliary (TPCA) and ophthalmic (OA) arteries were measured before, 2 days, 3 weeks and 6 months after the first injection. Patients were examined monthly and received 1-5 additional injections depending on ophthalmologic examination results. Results: Six months after the first injection, a significant increase in visual acuity 50.9 AE 25.9 versus 44.4 AE 21.7 (p < 0.01) and decrease in mean central macular thickness 267 AE 74 versus 377 AE 115 lm (p < 0.001) were observed compared to baseline. Although mean-BFVs decreased by 16%AE3% in CRA and 20%AE5% in TPCA (p < 0.001) 2 days after the first injection, no significant change was seen thereafter. Mean-BFVs in OA decreased by 19%AE5% at week 3 (p < 0.001). However, the smallest number of injections (two injections) was associated with the longest time interval between the last injection and month 6 (20 weeks) and with the best return to baseline levels for mean-BFVs in CRA, suggesting that ranibizumab had reversible effects on native retinal vascular supply after its discontinuation. Moreover, a significant correlation between the number of injections and percentage of changes in mean-BFVs in CRA was observed at month 6 (R = 0.74, p < 0.001) unlike TPCA or OA. Conclusion: Ranibizumab could impair the native choroidal and retinal vascular networks, but its effect seems reversible after its discontinuation.