BRONCHODILATOR DELIVERY BY METERED-DOSE INHALER IN VENTILATOR-SUPPORTED PATIENTS

The optimal dose and technique for administration of bronchodilators w ith a metered-dose inhaler (MDI) in mechanically ventilated patients h ave not been established. We studied the efficacy and safety of 10 puf fs (90 mu g/puff) of albuterol administered by an MDI in seven mechani cally ventilated patients with chronic obstructive pulmonary disease(C OPD). Rapid airway occlusions at constant flow inflation were performe d before and at 5-min intervals after administration of albuterol for 60 min. Significant decreases in maximum (R(rs)max; p < 0.01) and mini mum inspiratory resistance (R(rs)min; p < 0.01) were present at 5 min and persisted for 60 min after administration of albuterol (p < 0.01 f or both parameters). R(rs)max indicates maximal inspiratory resistance while R(rs)min represents the ohmic flow resistance. Intrinsic positi ve end-expiratory pressure decreased significantly (p < 005) 15 min af ter albuterol administration. Heart rate, blood pressure, and arterial oxygenation did not show significant change after albuterol. In summa ry, 10 puffs of albuterol given by an MDI and spacer produced signific ant bronchodilation in ventilator-supported patients with COPD without producing side effects. In conclusion, higher doses of albuterol give n by an MDI and spacer could be used routinely in mechanically ventila ted patients with COPD.