One-lung Ventilation in Pediatric Patients: Lung Isolation Techniques and Clinical Management

摘要

This review evaluates pediatric lung isolation techniques, emphasizing age-specific strategies: double-lumen tubes for children >8 years, intraluminal blockers for ages 2–8 years (ETT ID ≥4.5 mm), and extraluminal blockers or mainstem intubation for infants <2 years. It highlights how 3D printing and protective ventilation optimize safety.

摘要

Implementing one-lung ventilation (OLV) in pediatric patients presents unique clinical challenges due to age-dependent physiological and anatomical constraints. As minimally invasive thoracic surgery expands in pediatrics, the demand for precise lung isolation has increased. This narrative review evaluates current techniques—single-lumen tubes (SLT), double-lumen tubes (DLT), and bronchial blockers (BB)—with a focus on their safety profiles and clinical indications. Findings indicate that DLTs remain the benchmark for older children but are anatomically prohibitive for those under 8–10 years or shorter than 130 cm. BBs are the primary alternative for children aged 2–8 years (ETT ID ≥4.5 mm), although traditional devices such as the Arndt-Fogarty blockers have design limitations. For infants under 2 years, the primary strategies remain SLT mainstem intubation or extraluminal blocker placement, both of which carry a risk of right upper lobe (RUL) obstruction. Emerging innovations, particularly 3D-printed anatomically customized blockers, are highlighted as potential solutions to resolve device “fit” challenges in infants. Perioperative management remains non-standardized; however, evidence-based recommendations emphasize lung-protective ventilation to reduce pulmonary complications. Hypoxemia occurs in approximately 26% of pediatric OLV cases and requires a prioritized management framework that includes fiberoptic verification, secretion clearance, and optimized PEEP/CPAP application. By synthesizing current evidence, this review provides a decision-making algorithm to guide optimal device selection and improve safety outcomes in this vulnerable pediatric population.

引言

For anesthesiologists, managing one-lung ventilation (OLV) in children poses significantly greater challenges than in adults. As minimally invasive thoracoscopic and robotic surgical techniques continue to evolve and expand, the demand for OLV in pediatric thoracic surgery is increasing. In parallel, advances in the understanding of pediatric physiology and lower respiratory tract anatomy, along with the development of bronchial blocking devices and related technologies, have contributed to progress in pediatric lung isolation.

Under physiological conditions, the human body maintains a homeostatic balance between ventilation and perfusion (V/Q). In adult thoracic anesthesia, the lateral decubitus position utilizes gravitational and hydrostatic pressure gradients to optimize oxygenation within the dependent lung. In contrast, pediatric patients exhibit a heightened vulnerability to mismatch and subsequent hypoxemia during OLV^1,2. Several factors contribute to this disparity. First, the high compliance of the pediatric chest wall provides insufficient support for the dependent lung in the lateral position, reducing functional residual capacity (FRC) and predisposing the ventilated lung to airway closure and atelectasis following anesthesia induction³. Second, children derive less mechanical advantage from the diaphragm than adults. Additionally, the diminished hydrostatic pressure gradient in smaller bodies results in relatively decreased perfusion to the ventilated lung. Finally, the combination of reduced FRC and a metabolic rate approximately three times higher than that of adults (6–8 mL/kg/min vs. 2–3 mL/kg/min) markedly increases the risk of desaturation.

Anatomical disparities between pediatric and adult patients are equally critical in the context of lung isolation. The mean airway diameter in children follows a linear growth pattern from infancy through adolescence⁴, expanding from approximately 5 mm in neonates to 8 mm by 10 years of age⁵, and ultimately reaching adult dimensions of 15–20 mm⁶. Clinically, the left main bronchus is narrower than the right, necessitating the use of smaller endotracheal tubes for left-sided intubation. This constraint is particularly evident in infants aged 0–3 months, in whom the left main bronchus is often too small to accommodate even a 3.0 mm uncuffed tube². Furthermore, the “margin of safety” for the precise placement of isolation devices is severely limited in younger patients. In children under 8 years old, the distance from the carina to the orifice of the right upper lobe (RUL) is typically less than 1 cm. If a device inadvertently bypasses this orifice, it may result in ventilation of only the right middle and lower lobes, potentially causing severe hypoxemia or obstructing the operative field⁷. In contrast, the distance from the carina to the left upper lobe orifice is generally three times greater, providing a larger margin for error during left mainstem isolation⁸.

Therefore, the objective of this narrative review is to synthesize current evidence on pediatric lung isolation techniques, evaluate their clinical profiles, and provide a structured framework for perioperative management.