Real-Time Monitoring of Placental Oxygenation during Maternal Hypoxia and Hyperoxygenation Using Photoacoustic Imaging.

PURPOSE:This preclinical study aimed to evaluate placental oxygenation in pregnant rats by real-time photoacoustic (PA) imaging on different days of gestation and to specify variations in placental oxygen saturation under conditions of maternal hypoxia and hyperoxygenation. MATERIAL AND METHODS:Placentas of fifteen Sprague-Dawley rats were examined on days 14, 17, and 20 of pregnancy with a PA imaging system coupled to high-resolution ultrasound imaging. Pregnant rats were successively exposed to hyperoxygenated and hypoxic conditions by changing the oxygen concentration in inhaled gas. Tissue oxygen saturation was quantitatively analyzed by real-time PA imaging in the skin and 3 regions of the placenta. All procedures were performed in accordance with applicable ethical guidelines and approved by the animal care committee. RESULTS:Maternal hypoxia was associated with significantly greater decrease in blood oxygen saturation (ΔO2 Saturation) in the skin (70.74% ±7.65) than in the mesometrial triangle (32.66% ±5.75) or other placental areas (labyrinth: 18.58% ± 6.61; basal zone: 13.13% ±5.72) on different days of pregnancy (P<0.001). ΔO2 Saturation did not differ significantly between the labyrinth, the basal zone, and the decidua. After the period of hypoxia, maternal hyperoxygenation led to a significant rise in oxygen saturation, which returned to its initial values in the different placental regions (P<0.001). CONCLUSIONS:PA imaging enables the variation of blood oxygen saturation to be monitored in the placenta during maternal hypoxia or hyperoxygenation. This first preclinical study suggests that the placenta plays an important role in protecting the fetus against maternal hypoxia

Photoacoustic (PA) imaging of placental oxygenation on day 14 of gestation.

<p>From left to right: (A) the placenta in a sagittal plane (obtained by a B-mode ultrasound scan) and parametric images created with the PA Oxyhemo mode making possible the evaluation of blood oxygen saturation during variations in the oxygen levels supplied to the mother (5–100%). PA imaging sequences during hyperoxygenation (B), hypoxia (C) and hyperoxygenation (D).</p

Time-intensity curves obtained during the experimental sequence of hyperoxygenation (100% oxygen, 2.5 min), hypoxia (5% oxygen, 4 min), and hyperoxygenation (100% oxygen, 4 min) from skin (red), mesometrial triangle (light blue), basal zone (green), and labyrinth zone (dark blue) on day 20 of gestation.

<p>Time-intensity curves obtained during the experimental sequence of hyperoxygenation (100% oxygen, 2.5 min), hypoxia (5% oxygen, 4 min), and hyperoxygenation (100% oxygen, 4 min) from skin (red), mesometrial triangle (light blue), basal zone (green), and labyrinth zone (dark blue) on day 20 of gestation.</p

Regions of interest (ROIs) placed on the skin (red), the mesometrial triangle (light blue), and the two different zones of the placenta: the basal zone (green) and the labyrinth zone (dark blue).

<p>Regions of interest (ROIs) placed on the skin (red), the mesometrial triangle (light blue), and the two different zones of the placenta: the basal zone (green) and the labyrinth zone (dark blue).</p

Box-and-whisker plot showing ΔO₂ corresponded to the mean change in oxygen saturation between hyperoxygenated (100% oxygen supplied to mother) and hypoxic (5% oxygen supplied) saturation.

<p>(A) Represents maternal skin, the mesometrial triangle, and the whole placenta on different days of gestation. (B) Box-and-whisker plot represents the different part of the placenta<b>:</b> the basal zone and the labyrinth zone on different days of gestation. Data are mean values and 95% confidence intervals. Comparisons between skin and utero-placental regions of interest (mesometrial triangle and whole placenta) at the same day of gestation are indicated by *P = 0.05 **P = 0.01 ***P<0.001. Comparisons between mesometrial triangle and whole placenta at the same day of gestation are indicated by #P = 0.05 ## P = 0.01 ###P<0.001.</p

Quantitative analysis of oxygenation in the skin and the 3 regions of interest (ROIs) of the placenta, on days 14, 17 and 20 of gestation (pooled data).

<p>Results are presented as mean ± standard deviation.</p

Republication de: recommandations formalisées d'experts. Prise en charge de la patiente avec une pré-éclampsie sévère–RFE communes Société française d'anesthésie-réanimation (SFAR)–Collège national des gynécologues et obstétriciens français (CGNOF)

International audienceObjective: To provide national guidelines for the management of women with severe preeclampsia. Design: A consensus committee of 26 experts was formed. A formal conflict of interest (COI) policy was developed at the onset of the process and enforced throughout. The entire guidelines process was conducted independently of any industrial funding. The authors were advised to follow the principles of the Grading of Recommendations Assessment, Development and Evaluation (GRADE®) system to guide assessment of quality of evidence. The potential drawbacks of making strong recommendations in the presence of low-quality evidence were emphasized. Methods: The last SFAR and CNGOF guidelines on the management of women with severe preeclampsia was published in 2009. The literature is now sufficient for an update. The aim of this expert panel guidelines is to evaluate the impact of different aspects of the management of women with severe preeclampsia on maternal and neonatal morbidities separately. The experts studied questions within 7 domains. Each question was formulated according to the PICO (Patients Intervention Comparison Outcome) model and the evidence profiles were produced. An extensive literature review and recommendations were carried out and analyzed according to the GRADE® methodology. Results: The SFAR/CNGOF experts panel provided 25 recommendations: 8 have a high level of evidence (GRADE 1±), 9 have a moderate level of evidence (GRADE 2±), and for 7 recommendations, the GRADE method could not be applied, resulting in expert opinions. No recommendation was provided for 3 questions. After one scoring round, strong agreement was reached between the experts for all the recommendations. Conclusions: There was strong agreement among experts who made 25 recommendations to improve practices for the management of women with severe preeclampsia