Nitroglycerin can facilitate weaning of difficult-to-wean chronic
obstructive pulmonary disease patients: a prospective interventional
non-randomized study
Introduction: Both experimental and clinical data give convincing
evidence to acute cardiac dysfunction as the origin or a cofactor of
weaning failure in patients with chronic obstructive pulmonary disease.
Therefore, treatment targeting the cardiovascular system might help the
heart to tolerate more effectively the critical period of weaning. This
study aims to assess the hemodynamic, respiratory and clinical effects
of nitroglycerin infusion in difficult-to-wean patients with severe
chronic obstructive pulmonary disease.
Methods: Twelve difficult-to-wean (failed >= 3 consecutive trials)
chronic obstructive pulmonary disease patients, who presented systemic
arterial hypertension (systolic blood pressure >= 140mmHg) during
weaning failure and had systemic and pulmonary artery catheters in
place, participated in this prospective, interventional, non-randomized
clinical trial. Patients were studied in two consecutive days, i.e., the
first day without (Control day) and the second day with (Study day)
nitroglycerin continuous intravenous infusion starting at the beginning
of the spontaneous breathing trial, and titrated to maintain normal
systolic blood pressure. Hemodynamic, oxygenation and respiratory
measurements were performed on mechanical ventilation, and during a
2-hour T-piece spontaneous breathing trial. Primary endpoint was
hemodynamic and respiratory effects of nitroglycerin infusion. Secondary
endpoint was spontaneous breathing trial and extubation outcome.
Results: Compared to mechanical ventilation, mean systemic arterial
pressure, rate-pressure product, mean pulmonary arterial pressure, and
pulmonary artery occlusion pressure increased [from (mean +/- SD) 94
+/- 14, 13708 +/- 3166, 29.9 +/- 4.8, and 14.8 +/- 3.8 to 109 +/-
20mmHg, 19856 +/- 4877mmHg b/min, 41.6 +/- 5.8mmHg, and 23.4 +/- 7.4
mmHg, respectively], and mixed venous oxygen saturation decreased (from
75.7 +/- 3.5 to 69.3 +/- 7.5%) during failing trials on Control day,
whereas they did not change on Study day. Venous admixture increased
throughout the trial on both Control day and Study day, but this
increase was lower on Study day. Whereas weaning failed in all patients
on Control day, nitroglycerin administration on Study day enabled a
successful spontaneous breathing trial and extubation in 92% and 88%
of patients, respectively.
Conclusions: In this clinical setting, nitroglycerin infusion can
expedite the weaning by restoring weaning-induced cardiovascular
compromise