title: Effects of pleural effusion drainage on oxygenation, respiratory mechanics, and hemodynamics in mechanically ventilated patients.
abstract: OBJECTIVE
  In mechanically ventilated patients, the effect of draining pleural effusion on oxygenation is controversial. We investigated the effect of large pleural effusion drainage on oxygenation, respiratory function (including lung volumes), and hemodynamics in mechanically ventilated patients after ultrasound-guided drainage. Arterial blood gases, respiratory mechanics (airway, pleural and transpulmonary pressures, end-expiratory lung volume, respiratory system compliance and resistance), and hemodynamics (blood pressure, heart rate, and cardiac output) were recorded before and at 3 and 24 hours (H24) after pleural drainage. The respiratory settings were kept identical during the study period.
  
  
  RESULTS
  The mean volume of effusion drained was 1,579 ± 684 ml at H24. Uncomplicated pneumothorax occurred in two patients. Respiratory mechanics significantly improved after drainage, with a decrease in plateau pressure and a large increase in end-expiratory transpulmonary pressure. Respiratory system compliance, end-expiratory lung volume, and PaO2/FiO2 ratio all improved. Hemodynamics were not influenced by drainage. Improvement in the PaO2/FiO2 ratio from baseline to H24 was positively correlated with the increase in end-expiratory lung volume during the same time frame (r = 0.52, P = 0.033), but not with drained volume. A high value of pleural pressure or a highly negative transpulmonary pressure at baseline predicted limited lung expansion following effusion drainage. A lesser improvement in oxygenation occurred in patients with ARDS.
  
  
  CONCLUSIONS
  Drainage of large (≥500 ml) pleural effusion in mechanically ventilated patients improves oxygenation and end-expiratory lung volume. Oxygenation improvement correlated with an increase in lung volume and a decrease in transpulmonary pressure, but was less so in patients with ARDS.
authors: 1 Assistance Publique-Hôpitaux de Paris, GHU Henri Mondor, DHU A-TVB, Service de Réanimation Médicale, Groupe de Recherche CARMAS, Créteil, France.
authors: Keyvan
authors: K
authors: Razazi
authors: Arnaud W
authors: AW
authors: Thille
authors: Guillaume
authors: G
authors: Carteaux
authors: Olfa
authors: O
authors: Beji
authors: Christian
authors: C
authors: Brun-Buisson
authors: Laurent
authors: L
authors: Brochard
authors: Armand
authors: A
authors: Mekontso Dessap
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001784:Blood Gas Analysis; D015331:Cohort Studies; D003131:Combined Modality Therapy; D004322:Drainage / Q000379:methods*; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006785:Hospitals, University; D006801:Humans; D007362:Intensive Care Units; D016014:Linear Models; D008176:Lung Volume Measurements; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D010996:Pleural Effusion / Q000000981:diagnostic imaging / Q000628:therapy*; D011379:Prognosis; D012121:Respiration, Artificial / Q000009:adverse effects / Q000379:methods*; D012128:Respiratory Distress Syndrome / Q000175:diagnosis / Q000628:therapy*; D015656:Respiratory Mechanics; D016896:Treatment Outcome; D018608:Ultrasonography, Doppler
keywords: acute respiratory distress syndrome; drainage; lung volumes; oxygenation; pleural effusion