Aerosolized prostaglandin E₁ improves oxygenation during one-lung ventilation: A dose-finding randomized controlled...

This study aimed to investigate the effects of varying doses of aerosolized Prostaglandin E₁ (PGE₁) on oxygenation and intrapulmonary shunt fraction (Qs/Qt) during One-Lung Ventilation (OLV) under 60% Fraction of Inspired Oxygen (FiO₂). Secondary objectives included evaluating the impact on intraoperative hypoxemia, postoperative Clinical Pulmonary Infection Score (CPIS), and Postoperative Pulmonary Complications (PPCs).

A prospective, single center, randomized, double-blind, controlled trial.

The study was conducted at a single academic medical center.

A total of 160 patients aged 65‒84 years, with American Society of Anesthesiologists (ASA) physical status II or III and Body Mass Index (BMI) < 30 kg/m², undergoing elective esophageal cancer surgery were enrolled. Patients with certain comorbidities, respiratory diseases, or contraindications to PGE₁ were excluded.

Patients were randomly assigned to one of four groups: Group L ‒ Received 0.1 μg/kg PGE₁ nebulization; Group M ‒ Received 0.2 μg/kg PGE₁ nebulization; Group H ‒ Received 0.3 μg/kg PGE₁ nebulization; Group C (control) ‒ Received normal saline nebulization. Nebulization was performed for 10-minutes via a modified breathing circuit into the ventilated lung before initiating OLV.

Arterial blood gas parameters (arterial partial pressure of oxygen, PaO₂; arterial oxygen saturation, SaO₂; arterial partial pressure of carbon dioxide, PaCO₂), hemodynamic variables (Mean Arterial Pressure [MAP]; Heart Rate [HR]), respiratory mechanics (Peak airway pressure [Ppeak]; dynamic lung compliance [Cdyn]), PaO₂/FiO₂ ratio, and Qs/Qt were recorded at multiple time points during OLV. The incidence of intraoperative hypoxemia and hypotension, PPCs within 7-days, and CPIS on postoperative day-2 were also assessed.

All PGE₁ groups showed significantly improved PaO₂, SaO₂, and PaO₂/FiO₂ ratio, and reduced Qs/Qt during the first 30-minutes of OLV compared to the control group. The High-dose group (H) demonstrated the greatest improvement in oxygenation. The incidence of intraoperative hypoxemia [Group L: 0/40 (0%), Group M: 0/40 (0%), Group H: 0/40 (0%), Group C: 3/40 (7.5%)] and hypotension did not differ significantly among groups; however, the hypoxemia finding was exploratory as the study was not powered for this endpoint. No significant differences were observed in PPCs incidence among groups, but group H was associated with a lower CPIS on postoperative day-2 compared to group C. Hemodynamic changes were transient and clinically manageable.

Nebulized PGE₁ at doses of 0.1-0.3 μg/kg improves oxygenation and reduces Qs/Qt during OLV under 60% oxygen, with the 0.3 μg/kg dose being most effective. It did not significantly reduce the incidence of PPCs within 7-days. The incidence of intraoperative hypoxemia was lower in the PGE₁ groups (0/120) compared with the control group (3/40), but this was an exploratory finding as the study was not powered for this endpoint. The higher dose (0.3 μg/kg) was associated with a lower CPIS on postoperative day-2 (3.3 vs. 4.1), but CPIS is a surrogate marker, and this finding should be interpreted as exploratory. The clinical significance of this small difference is uncertain, as changes of this magnitude are below the typically recognized thresholds for meaningful clinical improvement. Hemodynamic monitoring is recommended when using higher doses of PGE₁.