Date of Award

January 2015

Document Type


Degree Name

Medical Doctor (MD)



First Advisor

Frank C. Detterbeck

Second Advisor

John Geibel

Subject Area(s)



Non-specific pleural effusion is common in patients after cardiac surgery. Thoracentesis for non- specific pleural effusion is being used more frequently with informal observations of improved dyspnea, shorter length of inpatient stay (LOS), reduced need for escalation of care, and less postoperative atrial fibrillation (AF). Our hypothesis is that the majority of cardiac surgery patients who undergo thoracentesis for non-specific pleural effusion have improvements in dyspnea, reduced days in AF, and reduced escalation of care compared to similar patients who do not have procedural intervention.

Our study population includes patients with evidence of pleural effusion on chest x-ray during a period postoperative day (POD) 3 - 7, after cardiac surgery performed by a single surgeon at Yale - New Haven Hospital, between Jan. 2013 and Dec. 2014. We have conducted a retrospective Case - Control Study (n = 30, 15/15). Cases are defined as having thoracentesis POD3 - POD7 and are matched by age and cardiac operation to Controls. We have recorded the frequency of improved dyspnea, as defined by ≥2 LPM reduction of daily peak O2 supplementation, after thoracentesis for Cases and compared this to the same period for matched Controls. Postoperative LOS, incidence of AF, and requirement for escalation of care are recorded and compared between Cases and Controls.

Dyspnea improved for 73% of Cases but this was not significantly different compared to Controls during matched periods (11 vs. 7 patients, OR = 3.1, p = 0.14). Length of stay was not different between Cases and Controls (6.7 vs. 5.8 days, p = 0.84) and there was no escalation of care required in either group (95% CI, 0.00 - 0.14). There was no difference in the odds of postoperative AF between Cases and Controls (OR = 0.22, p = 0.13). Patients who had thoracentesis performed before POD5 significantly lower incidence of postoperative AF (0 vs. 6 patients, p = 0.01).

We have concluded that the majority of patients have improvement in dyspnea after thoracentesis for non-specific pleural effusion after cardiac surgery. We observed that this improvement is not significantly different than that experienced by similar control patients. Thoracentesis did not decrease length of stay. Patients might experience fewer days in AF with thoracentesis when performed before POD5. Preoperative risk factors for postoperative AF were not evaluated, could have introduced selection bias for Cases, and therefore, limits this result.