title: The relationship of pleural pressure to symptom development during therapeutic thoracentesis.
abstract: OBJECTIVE
  To describe the relationship of patients' symptoms during therapeutic thoracentesis to pleural pressure (Ppl).
  
  
  METHODS
  Review of prospectively collected data during 169 therapeutic thoracentesis procedures.
  
  
  METHODS
  University Hospital in Boston, MA.
  
  
  METHODS
  One hundred sixty-nine patients who had Ppl measured during therapeutic thoracentesis were included in this study. End-expiratory pressures were measured after the withdrawal of 5 mL of fluid and every 240 mL thereafter until the pressure was lower than -20 cm H(2)O, chest discomfort developed in the patient, or no more fluid could be removed. Patients' symptoms, including chest pain, chest discomfort, and cough were recorded simultaneously.
  
  
  RESULTS
  There was no correlation between the amount of pleural fluid removed and the development of symptoms. The closing pressures and the total change in Ppl (see the "Materials and Methods" section for definitions), however, were significantly lower in the group of patients who experienced chest discomfort compared to patients who developed cough or were asymptomatic. There was also a trend toward a significantly lower pleural elastance in patients who developed cough compared to that in the other two groups. Additionally, only 22% of patients in whom chest discomfort developed, and 8.6% of patients in whom symptoms did not develop, had potentially dangerous Ppl values (ie, lower than -20 cm H(2)O).
  
  
  CONCLUSIONS
  The development of chest discomfort is associated with a potentially unsafe drop in Ppl values and should be a sign to terminate thoracentesis. It is not necessary to terminate thoracentesis solely because of the development of cough. Without attention to pleural manometry, a significant percentage of patients may develop potentially dangerous Ppl. Although we recommend pleural manometry with all thoracenteses, when it is not used attention to symptoms remains a valuable surrogate.
authors.affiliation: Interventional Pulmonology, Beth Israel Deaconess Medical Center, Deaconess 201, One Brookline Ave, Boston, MA 02215, USA. dfellerk@bidmc.harvard.edu
authors.forename: David
authors.initials: D
authors.lastname: Feller-Kopman
authors.forename: Allan
authors.initials: A
authors.lastname: Walkey
authors.forename: David
authors.initials: D
authors.lastname: Berkowitz
authors.forename: Armin
authors.initials: A
authors.lastname: Ernst
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002637:Chest Pain / Q000209:etiology; D003371:Cough / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D008365:Manometry; D008875:Middle Aged; D019152:Paracentesis / Q000009:adverse effects*; D010996:Pleural Effusion / Q000209:etiology / Q000503:physiopathology* / Q000628:therapy*; D011030:Pneumothorax / Q000209:etiology*; D011312:Pressure; D012189:Retrospective Studies