title: Temporal evolution of thoracocentesis-induced changes in spirometry and respiratory muscle pressures.
abstract: BACKGROUND
  Several studies investigated the effects of thoracocentesis on aspects of respiratory function without generally ensuring absence of coexistent lung pathology or homogeneity in initial size of the effusion.
  
  
  METHODS
  We studied 90 patients aged 61.6±15.9 years (mean±SD) separated into a group A with small-sized or medium-sized effusion (A=56 patients) and a group B with large and massive one (B=34 patients). There was no significant lung lesion or cardiovascular pathology. The basic spirometric parameters and maximal respiratory pressures were recorded on three instances: just before thoracocentesis (T1), 30 min after completion of the procedure (T2) and after 48 hours (T3).
  
  
  RESULTS
  At T2 vs T1, groups A and B respectively presented significant change (mean±SD) (increase) in forced vital capacity (FVC) of 0.071±0.232 and 0.139±0.224 L, in forced expiratory volume in 1 s (FEV1) of 0.127±0.231 and 0.201±0.192 L, in FEV1/FVC of 2.8% and 4.9%, in peak expiratory flow rate (PEFR) of 0.342±0.482 and 0.383±0.425 L/s, in maximal expiratory pressure (MEP) of 0.049±0.037 and 0.049±0.039 kPa and in maximal inspiratory pressure (MIP) of 0.040±0.041 kPa only in group A while decrease in MIP with significant change of 0.055±0.051 kPa in group B. At T3 vs T2 in groups A and B, there was significant change (decrease) in FEV1/FVC of 2.7% and 4.6% as well as significant change (increase) in MIP of 0.036±0.046 and 0.115±0.060 and in MEP of 0.049±0.043 and 0.070±0.048 kPa.
  
  
  CONCLUSIONS
  Thoracocentesis is associated with progressive-small relative to the volume of fluid removed-increases in lung volumes. In larger effusions at T2, a transient decrease in MIP is observed presumably due to temporary geometric distortion of the diaphragm immediately after fluid removal.
authors.affiliation: Department of Occupational Lung Diseases and Tuberculosis, "Sismanogleio-A. Fleming" General Hospital, Athens, Greece.
authors.forename: Stylianos A
authors.initials: SA
authors.lastname: Michaelides
authors.affiliation: Technological Educational Institute (T.E.I.) of Athens, Faculty of Health and Caring Professions, Athens, Greece.|Department of Physiology, Medical School, Democritus University of Thrace, Alexandroupolis, Greece.
authors.forename: George D
authors.initials: GD
authors.lastname: Bablekos
authors.affiliation: Department of Hygiene, Epidemiology and Medical Statistics, Medical School, National and Kapodistrian University of Athens, Athens, Greece.
authors.forename: Antonis
authors.initials: A
authors.lastname: Analitis
authors.affiliation: Department of Occupational Lung Diseases and Tuberculosis, "Sismanogleio-A. Fleming" General Hospital, Athens, Greece.
authors.forename: George
authors.initials: G
authors.lastname: Ionas
authors.affiliation: First Department of Pulmonary Medicine, "Sotiria" General Hospital, Athens, Greece.|Medical School, National and Kapodistrian University of Athens, Greece.
authors.forename: Petros
authors.initials: P
authors.lastname: Bakakos
authors.affiliation: Department of Physiology, Medical School, Democritus University of Thrace, Alexandroupolis, Greece.
authors.forename: Konstantinos A
authors.initials: KA
authors.lastname: Charalabopoulos
mesh_terms: D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010996:Pleural Effusion / Q000503:physiopathology* / Q000628:therapy*; D012132:Respiratory Muscles / Q000503:physiopathology*; D013147:Spirometry; D000069258:Thoracentesis; D016896:Treatment Outcome
keywords: Respiratory muscles pressures; Spirometry; Thoracocentesis