Surviving birth : resuscitation practice in Vietnam and the development of a supraglottic airway device

<p dir="ltr"><b>Background:</b> Each year, over 500,000 newborns die from intrapartum-related hypoxic events, formerly termed birth asphyxia. The true toll is thought to be nearly double due to misclassified stillbirths, and the associated morbidity is likely to exceed mortality, highlighting a substantial global burden. The overlap between intrapartum-related events and low birth weight is significant. Most of these deaths occur in low-resource settings and are preventable. Adequate resuscitation of the newborn can improve the outcome, with airway management and positive pressure ventilation as its cornerstones. Traditionally, face mask ventilation has been the first-line approach, with endotracheal intubation as the fallback when face mask ventilation fails. However, both methods can be technically challenging. The supraglottic airway device offers a promising alternative, but its role in reducing preventable deaths remains unclear, especially in low-birth-weight neonates, where evidence is scarce. This thesis aims to expand the broader understanding of neonatal morbidity, mortality, and resuscitation practices by illuminating the realities of neonatal care, particularly those related to airway management. It aims to advance the field by providing the first two structured anatomical feasibility studies of small supraglottic airway device prototypes aimed to be used in low-birth-weight neonates. The broader goal is to contribute to global efforts, inform global strategies, and reduce preventable neonatal deaths.</p><p dir="ltr"><b>Methods:</b> Between 2019 and 2025, two observational and two anatomic feasibility studies were conducted in Vietnam and Sweden. The observational studies took place at the Neonatal Unit, Phu San Hanoi Hospital, Vietnam: a retrospective cross-sectional study (Study I) and a prospective, video-based study (Study II). These explored causes of neonatal morbidity and mortality, detailed airway management during neonatal resuscitation in the delivery room, and broader clinical management practices in the neonatal unit. The feasibility studies were conducted at the Radiology Department, Karolinska University Hospital, Huddinge, Sweden, and assessed the anatomic feasibility of three small supraglottic airway device prototypes using high-fidelity manikins representing low-birth-weight neonates (Study III) and stillborn low-birth-weight neonates (Study IV). The device under investigation was the i-gel®, a cuffless supraglottic airway device previously shown to be safe in low-resource settings when used by midwives. We evaluated the smallest currently commercially available size (1.0) along with three smaller prototypes (sizes 0.85, 0.75, and 0.65).</p><p dir="ltr"><b>Results:</b> At Phu San Hanoi Hospital (Studies I and II), the most common neonatal diagnoses were prematurity, jaundice, respiratory distress, and infection. Intrapartum-related events were less frequent, as reflected by the need for positive pressure ventilation, accounting for only 5% of admissions to the neonatal unit, and a diagnosis of hypoxic-ischemic encephalopathy, accounting for 1% of admissions. Nearly 40% of the neonates admitted to the neonatal unit had a low birth weight (<2,500 grams), increasing to 55% among those needing positive pressure ventilation at birth. The overall rate of positive pressure ventilation among all in-hospital births was 0.4-0.6%, with 0.2% requiring endotracheal intubation. Three of four intubations were successful on the first attempt, with only one case of complete failure. However, intubation success declined with lower birth weight, with up to five attempts required in one case, and more than half exceeded the recommended 30-second threshold for intubation attempt duration. In the anatomic feasibility studies (Studies III and IV), three high-fidelity manikins and six stillborn neonates, weighing between 500 and 2,250 grams, were included. The smallest commercially available i-gel® (size 1.0) was too large to be considered an optimal fit for all subjects in this weight range. Prototype sizes 0.85 and 0.75 consistently fitted well for manikins and stillborn neonates weighing between 900 and 2,250 grams. For manikins and neonates weighing between 500 and 750 grams, results were inconclusive due to variability in fit.</p><p dir="ltr"><b>Conclusions:</b> This thesis provides essential baseline data on the clinical realities of neonatal care at a busy referral hospital in Vietnam, a lower middle- income country. It highlights the strong overlap between low birth weight and intrapartum-related events. It reveals the limitations of endotracheal intubation in real-world practice, including the frequent need for prolonged and repeated attempts. These findings underscore the urgent need for alternative, easier airway management techniques during resuscitation of the newborn, including smaller, more suitable alternatives for low-birth-weight neonates. By delivering the first structured anatomical feasibility data on supraglottic airway device use in low-birth-weight high-fidelity neonatal manikins and stillborn neonates, this thesis advances the field and positions the supraglottic airway device as a promising cornerstone of future strategies to reduce neonatal mortality worldwide.</p><h3>List of scientific papers</h3><p dir="ltr">I. <b>Tina Dempsey</b>, Huong Lien Nguyen, Huong Thu Nguyen, Xuan Anh Bui, Phuong Thi Thu Pham, Toan K. Nguyen, Francesco Cavallin, Daniele Trevisanuto, Susanna Myrnerts Höök, Nicolas Pejovic, Mats Blennow, Linus Olson, Hien Vu, Anh Duy Nguyen, Tobias Alfvén. Incidence of Intrapartum-Related Events at the Largest Obstetric Hospital in Hanoi, Vietnam: A Retrospective Study. Children. 2022; 9: 321. <a href="https://doi.org/10.3390/children9030321" rel="noreferrer" target="_blank">https://doi.org/10.3390/children9030321</a></p><p dir="ltr">II. <b>Tina Dempsey</b>*, Huong Thu Nguyen, Huong Lien Nguyen, Xuan Anh Bui, Phuong Thi Thu Pham, Toan K Nguyen, Daniel Helldén, Francesco Cavallin, Daniele Trevisanuto, Susanna Myrnerts Höök, Mats Blennow, Linus Olson, Hien Vu, Anh Duy Nguyen, Tobias Alfvén*, Nicolas Pejovic *. Endotracheal intubation performance at a large obstetric hospital delivery room, Hanoi, Vietnam. Resuscitation Plus. 2022; 12: 100338. *equal contribution <a href="https://doi.org/10.1016/j.resplu.2022.100338" rel="noreferrer" target="_blank">https://doi.org/10.1016/j.resplu.2022.100338</a></p><p dir="ltr">III. <b>Tina Dempsey</b>, Torkel Brismar, Anders Svensson-Marcial, Mats Blennow, Tobias Alfvén, Susanna Myrnerts Höök, Nicolas Pejovic. Radiologic Evaluation of Three Smaller-Sized Supraglottic Airway Device Prototypes for Low-Birth-Weight Neonates. British Journal of Anaesthesia - published online in July 2025. <a href="https://doi.org/10.1016/j.bja.2025.05.038" rel="noreferrer" target="_blank">https://doi.org/10.1016/j.bja.2025.05.038</a></p><p dir="ltr">IV. <b>Tina Dempsey</b>, Torkel Brismar, Anders Svensson-Marcial, Mats Blennow, Tobias Alfvén, Nicolas Pejovic, Susanna Myrnerts Höök. Computed Tomography of Three Smaller-Sized Supraglottic Airway Device Prototypes in Stillborn Low-Birth-Weight Neonates. [Manuscript]</p>