Effects of dexmedetomidine on oxygenation and lung mechanics in patients with moderate chronic obstructive pulmonary disease undergoing lung cancer surgery : A randomised double-blinded trial

Abstract

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a risk factor that increases the incidence of postoperative cardiopulmonary morbidity and mortality after lung resection. Dexmedetomidine, a selective α ₂-adrenoreceptor agonist, has been reported previously to attenuate intrapulmonary shunt during one-lung ventilation (OLV) and to alleviate bronchoconstriction.

OBJECTIVE

The objective is to determine whether dexmedetomidine improves oxygenation and lung mechanics in patients with moderate COPD during lung cancer surgery.

DESIGN

A randomised, double-blinded, placebo-controlled study.

SETTING

Single university hospital.

PARTICIPANTS

Fifty patients scheduled for video-assisted thoracoscopic surgery who had moderate COPD. Patients were randomly allocated to a control group or a Dex group ( n = 25 each).

INTERVENTIONS

In the Dex group, dexmedetomidine was given as an initial loading dose of 1.0 μg kg ⁻¹ over 10 min followed by a maintenance dose of 0.5 μg kg ⁻¹ h ⁻¹ during OLV while the control group was administered a comparable volume of 0.9% saline. Data were measured at 30 min (DEX-30) and 60 min (DEX-60) after dexmedetomidine or saline administration during OLV.

MAIN OUTCOME MEASURES

The primary outcome was the effect of dexmedetomidine on oxygenation. The secondary outcome was the effect of dexmedetomidine administration on postoperative pulmonary complications.

RESULTS

Patients in the Dex group had a significantly higher PaO ₂/F iO ₂ ratio (27.9 ± 5.8 vs. 22.5 ± 8.4 and 28.6 ± 5.9 vs. 21.0 ± 9.9 kPa, P < 0.05), significantly lower dead space ventilation (19.2 ± 8.5 vs. 24.1 ± 8.1 and 19.6 ± 6.7 vs. 25.3 ± 7.8%, P < 0.05) and higher dynamic compliance at DEX-30 and DEX-60 ( P = 0.0001 and P = 0.0184) compared with the control group. In the Dex group, the PaO ₂/F iO ₂ ratio in the postoperative period was significantly higher ( P = 0.022) and the incidence of ICU admission was lower than in the control group.

CONCLUSION

Dexmedetomidine administration may provide clinically relevant benefits by improving oxygenation and lung mechanics in patients with moderate COPD undergoing lung cancer surgery.

TRIAL REGISTRATION

ClinicalTrial.gov identifier: NCT 02185430.