Effects of Iloprost on Oxygenation during One-Lung Ventilation in Patients with Low Diffusing Capacity for Carbon Monoxide: A Randomized Controlled Study.

Kyuho Lee,Mina Kim,Sei Han Song,Young Jun Oh,Namo Kim

doi:10.3390/jcm11061542

Kyuho Lee, Mina Kim + Show 3 more

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https://doi.org/10.3390/jcm11061542

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Abstract

The protective mechanism of hypoxic pulmonary vasoconstriction during one-lung ventilation (OLV) is impaired in patients with a low diffusing capacity for carbon monoxide (DLCO). We hypothesized that iloprost inhalation would improve oxygenation and lung mechanics in patients with low DLCO who underwent pulmonary resection. Forty patients with a DLCO < 75% were enrolled. Patients were allocated into either an iloprost group (ILO group) or a control group (n = 20 each), in which iloprost and saline were inhaled, respectively. The partial pressure of arterial oxygen/fraction of inspired oxygen (PaO2/FiO2) ratio, pulmonary shunt fraction, alveolar dead space, dynamic compliance, and hemodynamic parameters were assessed 20 min after the initiation of OLV and 20 min after drug administration. Repeated variables were analyzed using a linear mixed model between the groups. Data from 39 patients were analyzed. After iloprost inhalation, the ILO group exhibited a significant increase in the PaO2/FiO2 ratio and a decrease in alveolar dead space compared with the control group (p = 0.025 and p = 0.042, respectively). Pulmonary shunt, dynamic compliance, hemodynamic parameters, and short-term prognosis were comparable between the two groups. Selective iloprost administration during OLV reduced alveolar dead space and improved oxygenation while minimally affecting hemodynamics and short-term prognosis.

Highlights

One-lung ventilation (OLV) is required for operative procedures in the thoracic cavity.OLV aggravates ventilation–perfusion (V/Q) mismatch and commonly results in hypoxemia, which has an incidence of 5–10% [1]
This study aimed to investigate the effects of iloprost on oxygenation and lung mechanics in patients with low DLCO who underwent OLV
We demonstrated that the selective administration of iloprost to ventilated lungs during OLV significantly reduced alveolar dead space and improved oxygenation in patients with low DLCO

Summary

Introduction

One-lung ventilation (OLV) is required for operative procedures in the thoracic cavity. OLV aggravates ventilation–perfusion (V/Q) mismatch and commonly results in hypoxemia, which has an incidence of 5–10% [1]. Hypoxemia of the nonventilated lung triggers hypoxic pulmonary vasoconstriction (HPV), an autoregulatory mechanism that decreases the shunt fraction by diverting total pulmonary blood flow from the nonventilated lung to the ventilated lung [2,3]. The diffusing capacity for carbon monoxide (DLCO) measures the ability of the gas to diffuse across the alveolar–capillary membrane [4]. Reduced DLCO is an independent risk factor for increased mortality and perioperative complications related to hypoxia [5,6]. The risk of hypoxia is further increased when patients with low DLCO undergo surgeries requiring OLV because the protective mechanism of HPV is impaired owing to altered compliance of the pulmonary artery [7]

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