The use of lung ultrasound during the COVID-19 pandemic: A narrative review with specific focus on its role in pregnancy.

The novel coronavirus disease (COVID-19) is a challenge to every health system. Unfortunately, it is unlikely that this pandemic will disappear soon. No health system, with its present resources and workflow, is capable enough to deal with a full-blown wave of this pandemic. Acquisition of specific new skills may be fundamental in delivering appropriate health care for our patients. The gold standard for diagnosis of the COVID-19 infection is real-time reverse transcription polymerase chain reaction. Radiological investigations (chest X-ray or high-resolution computerized tomography [CT]) can be helpful both for diagnosis and management, but they have many limitations. Ultrasound has been suggested as a reliable and accurate tool for assessing the lungs in COVID-19 patients. Lung ultrasound (LUS) can show specific signs of interstitial pneumonia, which is characteristic of COVID-19 pulmonary infection. In addition, nonradiologist specialists with experience in ultrasound can be trained on LUS with a relatively rapid learning curve. In pregnancy, LUS can be particularly useful due to the avoidance of exposure to ionizing radiation. In this review, we present the advantages, techniques, and limitations of the use of LUS during the COVID-19 pandemic, with specific focus on pregnancy.

Automated Measurement of the Angle of Progression in Labor: A Feasibility and Reliability Study.

OBJECTIVES: The aim of this paper was to assess the feasibility and reliability of a new automated method for the measurement of the angle of progression (AoP) in labor. METHODS: AoP was assessed using two-dimensional transperineal ultrasound by two operators in 52 women in active labor to evaluate intra- and interobserver reproducibility. The intermethod agreement between automated and manual techniques was analyzed by means of the intraclass correlation coefficient and Bland-Altman method. RESULTS: Automated measurements were feasible in all cases. Automated assessments correctly depicted the pubic symphysis and fetal head in 133 (85.3%) out of 156 on first assessments and in all 156 after repeating measurements once in case of incorrect first evaluation. The automated technique showed good intra- and interobserver reproducibility and very good agreement with the manual technique. AoP measured by the automated method were significantly wider than those done by the manual technique (119 ± 20° vs. 130 ± 20°, p = 0.005). CONCLUSIONS: Automated assessment AoP is feasible and reproducible. However, measurements performed by the automated software are significantly different from those resulting from the previously published manual technique. In the light of our data, the automated technique does not seem ready yet for clinical use, and the AoP should be exclusively measured by the previously suggested manual technique.

Agreement between two 3D ultrasound techniques for the assessment of the subpubic arch angle.

OBJECTIVES: To assess the reliability of a new three-dimensional (3D) ultrasound technique for the measurement of the subpubic arch angle (SPA) and the agreement between two contrast-enhancing 3D ultrasound techniques. METHODS: We acquired two static 3D transperineal volumes from 72 nulliparous women using two ultrasound machines equipped with two different 3D contrast enhancement and linear reconstruction softwares: 1. Oblique View Extended Imaging with HD-Volume Imaging (OVIX-HDVI™), Samsung; 2. Omniview with Volume Contrast Imaging (Omniview-VCI™), GE Healthcare. An operator measured SPA once by OVIX-HDVI, and twice by Omniview-VCI, while another operator measured SPA once by Omniview-VCI. We evaluated intra- and inter-observer reproducibility of Omniview-VCI and intermethod agreement. Reproducibility and intermethod agreement were studied by means of intraclass correlation coefficient (ICC) and Bland-Altman method. RESULTS: Omniview-VCI SPA measurements showed excellent intraobserver and interobserver reproducibility (ICC 0.970; 95% C.I. 0.952 to 0.981, 0.932; 95% C.I. 0.893 to 0.957, respectively). Furthermore, Omniview VCI SPA measurements demonstrated excellent agreement with those performed by OVIX-HDVI technique (ICC 0.943; 95 C.I. 0.911 to 0.964). No systematic difference was found in any of the reliability studies. CONCLUSIONS: OmniView-VCI is a reliable method for SPA assessment. Both OmniView-VCI and OVIX-HDVI can be used interchangeably for SPA measurement.

The "occiput-spine angle": a new sonographic index of fetal head deflexion during the first stage of labor.

BACKGROUND: Fetal head "attitude" (relationship of fetal head to spine) in the first stage of labor may have a substantial impact on labor outcome. The diagnosis of fetal head deflexion traditionally is based on digital examination in labor, although the use of ultrasound to support clinical diagnosis has been recently reported. OBJECTIVES: The aims of this study were: (1) to quantify the degree of fetal head deflection via the use of sonography during the first stage of labor; and (2) to determine whether a parameter derived from ultrasound examination (the occiput-spine angle) has a relationship with the course and outcome of labor. STUDY DESIGN: This was a prospective multicentric, cross-sectional study conducted at the Maternity Unit of the University of Bologna and Parma from January 2014 to April 2015. A nonconsecutive series of women with uncomplicated singleton pregnancies at term gestation (37 weeks or more) were submitted to transabdominal ultrasound during the first stage of labor. If fetal position was occiput anterior or transverse, the angle between the fetal occiput and the cervical spine (the occiput-spine angle) was sonographically obtained on the sagittal plane. The measurements of the occiput spine-angle were performed offline by 2 operators who were blinded to the labor outcome. The intra- and interobserver reproducibility and the correlation between the occiput-spine angle and the mode of delivery were evaluated. RESULTS: A total of 108 pregnant women were recruited, 79 of which underwent a spontaneous vaginal delivery and 29 were submitted to obstetric intervention (19 cesarean delivery and 10 instrumental vaginal deliveries). The mean value of the occiput-spine angle measured in the active phase of the first stage was 126° ± 9.8° (SD). The occiput-spine angle measurement showed a very good intraobserver (r = 0.86; 95% confidence interval [95% CI] 0.80-0.90) and a fair-to-good interobserver (r = 0.64; 95% CI 0.51-0.74) agreement. The occiput-spine angle was significantly narrower in women who underwent obstetric intervention (cesarean or vacuum delivery) due to labor arrest (121° ± 10.5° vs 127° ± 9.4°, P = .03). Multivariable logistic regression analysis showed that narrow occiput-spine angle values (OR 1.08; 95% CI 1.00-1.16; P = .04) and nulliparity (OR 16.06; 95% CI 1.71-150.65; P = .02) were independent risk factors for operative delivery. A larger occiput-spine angle width (i.e., >125°) showed to be significantly associated with a shorter duration of labor (hazard ratio = 1.62; 95% CI 1.07-2.45; P = .02). CONCLUSION: We described herein the "occiput-spine angle," a new sonographic parameter to assess fetal head deflection during labor. Fetuses with smaller occiput-spine angle (<125°) are at increased risk for operative delivery.