Favorable outcome in a renal transplant recipient with donor-derived infection due to multidrug-resistant Pseudomonas aeruginosa

Most cases of donor-derived infection due to Pseudomonas aeruginosa reported in the literature are associated with vascular dehiscence, all of which resulted either in death or graft failure requiring graft removal. We report the successful treatment of donor-derived infection due to multidrug-resistant P. aeruginosa in a 64-year-old male who presented with bacteremia and peritransplant renal fluid collection after undergoing deceased-donor renal transplantation. As a result of the report of positive donor cultures by the host Organ Procurement Organization, the infection was promptly identified by blood cultures drawn before appearance of symptoms. Surveillance blood cultures in recipients are not usually recommended. However, they should be done if donor cultures turn positive. Therefore, it is crucial to perform cultures in donors and to closely follow them up for early identification and prompt treatment of donor-transmitted infections due to organisms like P. aeruginosa that can be graft and/or life threatening.     

Candida arteritis in kidney transplant recipients: case report and review of the literature

Multi‐organ procurement is a risk factor for contamination of preservation fluid with intestinal flora including fungi (e.g., Candida). Transmission of fungal species to the graft vessel can cause mycotic arteritis. This is a very rare but life‐threatening complication of renal transplantation. We present 2 cases of renal transplant recipients from the same multi‐organ donor. Both recipients suffered from severe hemorrhages from renal graft anastomosis and renal artery pseudoaneurysm due to Candida albicans arteritis (CAA). The culture of the preservation fluid revealed growth of Escherichia coli, but neither preservation fluid nor multiple routine blood cultures performed before hemorrhagic complications revealed fungal growth (media non‐selective for fungal growth were applied). The first recipient suffered from sudden severe hemorrhage in the area of graft anastomosis on day 10 post surgery (without any preceding clinical or radiological symptoms). This led to urgent surgery and graftectomy, which was complicated by cardio‐respiratory arrest with resuscitation in the operating room; despite resuscitation, irreversible brain damage, and subsequent death occurred in the intensive care unit (ICU) 2 weeks later (on day 24 after transplantation). The second patient underwent urgent vascular surgery on day 22 (after transplantation), because of hemorrhage from a pseudoaneurysm of the graft artery. She required repeated vascular operations, extended antimicrobial and antifungal therapy, and ICU monitoring and, despite these interventions, she died on day 80 after transplantation as a result of Pseudomonas aeruginosa sepsis. Arteritis of the renal artery in both patients was caused by C. albicans. This was confirmed by histopathology: infiltration of renal artery with budding yeast forming pseudohyphae (Case 1), and the presence of C. albicans in the culture of the renal artery and surrounding tissue (Case 2). We conclude that organ preservation solution should be cultured with use of media selective for fungal growth. As soon as the positive culture is detected, appropriate measures protecting patients against CAA should be undertaken.     

Microbiological findings of culture‐positive preservation fluid in liver transplantation

S. Janny, F. Bert, F. Dondero, F. Durand, P. Guerrini, P. Merckx, M.H. Nicolas‐Chanoine, J. Belghiti, J. Mantz, C. Paugam‐Burtz. Microbiological findings of culture‐positive preservation fluid in liver transplantation.
Transpl Infect Dis 2011: 13: 9–14. All rights reserved Abstract: Bacterial and fungal infections are the leading cause of mortality in liver transplant (LT) recipients. Few studies have examined the incidence of culture‐positive preservation fluid (PF) and the outcome of related recipients. The aim of this study was to determine the incidence and the microbiologic findings of PF positive cultures, and to evaluate the impact on morbidity and mortality of LT recipients. A retrospective analysis of PF cultures performed after 477 LTs from cadavaric grafts between January 2001 and February 2008 was conducted. Forty‐five (9.5%) PFs were found to be positive with 1 or 2 pathogens. The demographic profiles of recipients of PF with positive or negative cultures were similar. Enterobacteriaceae species were the most frequent organisms (n=30), followed by Staphylococcus aureus (n=5), coagulase‐negative staphylococci (n=5), enterococci (n=4), and yeasts (n=3). Mortality rate at 1 month was not significantly different in recipients with positive or sterile PF cultures (88.1% vs. 87.7%, respectively). The rate of bacteremia among LT recipients with positive or negative PF cultures was not statistically different. Systemic infections caused by the pathogen cultured from the PF occurred in 8 (18%) of the 45 recipients, including bacteremia (4/8) or intra‐abdominal sepsis (5/8). Causative organisms were Enterobacteriaceae species (n=5), Candida species (n=2), and Enterococcus faecium (n=1). Among the 8 patients who developed infection with the PF organism, 4 (50%) died in the intensive care unit (ICU) vs. an ICU mortality rate of 8% (3/37) in those who did not develop infection with the PF organism (P<0.05). Infection occurred less frequently in recipients who received antimicrobial therapy with activity against the PF isolate than in those without appropriate treatment (41% vs. 3.8%, P<0.005). Those who develop infection with organisms recovered from PF cultures appear to have high early mortality rates; therefore, appropriate antimicrobial therapy against organisms cultured from PF should be given.     

Outcomes of transplantation using organs from a donor infected with Klebsiella pneumoniae carbapenemase (KPC)‐producing K. pneumoniae

Transmission of pathogens from donor to recipient is a potential complication of organ transplantation. Herein, we describe the clinical course and outcomes of 4 transplant recipients who received tissues from a donor with multi‐organ infection with Klebsiella pneumoniae carbapenemase (KPC)‐producing K. pneumoniae. Recipient 1 underwent simultaneous liver and kidney transplantation for alpha‐1 antitrypsin deficiency and alcohol‐related cirrhosis, and acute tubular necrosis, respectively. Soon after transplantation, he developed an infected hematoma and peritonitis due to KPC‐producing K. pneumoniae despite receiving tigecycline prophylaxis. He was treated with a prolonged course of tigecycline, amikacin, and meropenem, in conjunction with surgical evacuation and percutaneous drainage of the infected fluid collections. Recipient 2 underwent living‐donor liver transplantation for cholangiocarcinoma and primary sclerosing cholangitis using vein graft from the donor infected with KPC‐producing K. pneumoniae. Culture of the preservation fluid containing the vein graft was positive for KPC‐producing K. pneumoniae. The patient received preemptive amikacin and tigecycline, and he did not develop any infection (as evidenced by negative surveillance blood cultures). The isolates from the donor and Recipients 1 and 2 were indistinguishable by pulsed‐field gel electrophoresis. Recipients 3 and 4 underwent kidney and heart transplantation, respectively; both patients received perioperative tigecycline prophylaxis and did not develop infections due to KPC‐producing K. pneumoniae. All transplant recipients had good short‐term outcomes. These cases highlight the importance of inter‐institutional communication and collaboration to ensure the successful management of recipients of organs from donors infected with multidrug‐resistant organisms.     

Low yield of microbiologic studies on pleural fluid specimens

BACKGROUND: It is generally recommended that pleural fluid samples from pleural effusions of unknown cause be cultured for bacteria, mycobacteria, and fungi. However, the utility of this practice has been not been adequately assessed. DESIGN: Retrospective review. SETTING: Tertiary care, referral medical center. PATIENTS: Five hundred twenty-five patients undergoing diagnostic thoracentesis at Mayo Medical Center, Rochester, MN, over a 12-month period from July 1, 2001, to June 30, 2002. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Among 525 patients undergoing diagnostic thoracenteses, 476 patients (91%) had one or more cultures performed on their pleural fluid specimens. Thirty-nine positive results (3.0% of 1,320 cultures) occurred in 35 of these 476 patients (7.4%). After excluding likely contaminants, true pathogens were identified in only 19 of 1,320 pleural fluid cultures (1.4%) belonging to 15 patients (3.2% of those who had cultures performed on their pleural fluid specimen). These positive results included 2.3% of aerobic bacterial, 1.2% of anaerobic bacterial, 1.4% of fungal, and 0% of mycobacterial cultures. Microbiologic smears performed on these pleural fluid samples included 357 Gram stains, 109 fungal smears (potassium hydroxide), and 232 acid-fast smears with positive yields of 2.5%, 0%, and 0%, respectively. These positive findings represented 1.3% of all smears performed. Of the specimens obtained from outpatient thoracenteses, only one had a true-positive result (0.8%). Only 1.1% (four specimens) of the cultures performed on free-flowing effusions demonstrated true pathogens; three of these four specimens grew fungi. CONCLUSIONS: The positive yield of microbiologic smears and cultures on pleural fluid specimens is low, particularly in the outpatient setting and in patients with free-flowing effusions. Microbiologic testing of pleural fluid specimens should be ordered more selectively.     

The relevance of cultures of catheter-drawn blood and heparin-lock fluid to diagnose infection in hematologic patients

Summary The results of bacteriologic cultures of blood and heparin-lock fluid, both drawn from the central venous catheters of 54 consecutive oncohematologic patients, have been used to determine their value for the diagnosis of systemic and catheter-associated infection. In 30 patients with clinical signs of infection (bacteremia or septicemia), 74 of 1000 (7.4%) heparin-lock fluid cultures, 114 of 542 (21%) catheter-drawn blood cultures, and 36 of 134 (26%) venipuncture blood cultures became positive, whereas in 24 patients without clinical signs of infection the respective values were 5 of 700 (0.7%), one of 220 (0.4%), and none of ten cultures. Comparison of the results of cultures sampled on the same day reveals that the positive and negative predictive values for catheter-drawn blood cultures, with the venipuncture blood cultures taken as the standard for bacteremia, are 82% and 95% respectively. The results of heparin-lock fluid are indicative for clinically relevant colonization of the catheter. Three or more positive heparin-lock fluid cultures, sampled on subsequent days, were correlated with the occurrence of bacteremia or septicemia with a positive predictive value of 100%. The conclusions are supported by the results of scanning electron microscopy.     

Bacterial contamination of organ graft preservation solution and infection after transplantation

M. Sauget, S. Verdy, C. Slekovec, X. Bertrand, D. Talon. Bacterial contamination of organ graft preservation solution and infection after transplantation.
Transpl Infect Dis 2011: 13: 331–334. All rights reserved Abstract: Infectious complications represent a major cause of morbidity and mortality in patients with organ transplantation. Contamination of preservation solution (PS) can lead to life‐threatening complications in the recipients. For a 3‐year period, we investigated the bacterial contamination of both PSs and graft fragments, recipient infections, and explored the link between them. In total 137 organs were transplanted, and 131 organ and perfusate cultures out of 426 tested (30.8%) gave a positive bacterial culture, mainly with coagulase‐negative staphylococci. Overall, 80 recipients out of 137 (58.4%) had at least 1 infection during the 4‐month post‐graft surveillance period. Twelve recipients had an infection with the same bacterial species that was recovered in the corresponding graft. However, based on pulsed‐field gel electrophoresis typing results, only 1 case was very likely cross‐transmitted via the transplantation.     

Influence of preservation solution on early graft failure in clinical lung transplantation.

The aim of this study was to assess the influence of preservation solution type and extra- or intracellular composition on the occurrence of early graft dysfunction after clinical lung transplantation. For 170 patients who underwent a single (n = 124) or bilateral (n = 46) lung transplantation in two centers in Paris between 1988 and 1999, the preservation technique applied to the donor lung was single-flush perfusion of the pulmonary artery with one of several solutions of intracellular (Euro-Collins, n = 61; University of Wisconsin, n = 24) or extracellular composition (Cambridge, n = 64; Celsior, n = 21). The early postoperative outcome of these patients was reviewed. Reimplantation edema occurred in 48% of all patients, and the overall 1-mo survival rate was 84%. No significant difference in the incidence of edema, duration of mechanical ventilation, and 1-mo survival rate was observed between the four groups or between intra- and extracellular groups. After adjustment for graft ischemic time by means of multivariate analysis, the use of extracellular preservation fluid was associated with a lower incidence of reimplantation edema without effect on 1-mo mortality. Graft ischemic time was associated with both edema occurrence and 1-mo survival rate (p = 0.02 and p = 0.01, respectively). We conclude that extracellular-type solutions are associated with better lung preservation than intracellular-type solutions in clinical transplantation.     

Liver graft preservation:an overview

Liver graft preservationT he viability of the organ and its maintenance are very important during any transplant procedure and there is usually a period between the stoppage of the circulation in the donor and re-vascularisation of the organ in the recipient. During this period the harvested organ may have an irreversible harmful series of events rendering it not suitable for transplantation. This non-reversible damage which occurs during the ischaemic period depends partly on the metabolic re…     

Intraoperative microbiological monitoring in abdominal aortic aneurysms in elective surgery. A review of the literature and the authors' personal experience]

Thirty-one patients, ranging in age from 57 to 78 years (mean 66), with the exclusion of cases with doubtful possible results, underwent abdominal aortic aneurysmectomy for asymptomatic AAA and had cultures from the aneurysmal wall and endovascular thrombus to identify possible microbiological source of future graft infection; 5 (16%) of 31 cultures yielded bacterial growth and the most common organism isolated was staphylococcus epidermidis. During an average follow-up of 15.4 months no graft infection was noted in patients with positive or negative aortic cultured. A literature review stresses the same disparity between positive cultures obtained at the aneurysmectomy and subsequent low graft-infection rate. It is concluded that the aneurysm wall itself does not represent an important source of early or late graft infection and it's suggested that the bacterial presence both in the wall and thrombus could be explained by an exogenous contamination at the operation time.     

Effect of Candida infection on outcome in patients with perforation peritonitis

Perforation peritonitis is treated with surgery and antibiotics. This study was conducted to identify bacterial and fungal microorganisms responsible for peritonitis in patients with hollow viscus perforation and to examine the influence of these microorganisms on the outcome. A prospective study was conducted from May 2005 to September 2006 involving 84 consecutive patients with spontaneous gastrointestinal perforation peritonitis, who were referred for surgery. Peritoneal fluid was analyzed by microbial culture and biochemical tests for bacteria and fungi. The Jabalpur Prognostic Score was calculated. Forty-two of the 84 patients had positive peritoneal fluid cultures. Escherichia coli was the most common bacterium (n=26) and Candida (n=13) the most common fungus isolated. Bacterial isolates were largely sensitive to amikacin while all the Candida isolates were sensitive to fluconazole. Mortality was significantly higher in patients with positive peritoneal cultures (15/42) compared with those with negative peritoneal cultures (0/42, p< 0.001), and in patients with mixed bacterial and fungal-positive cultures (10/13) compared with those with isolated bacterial cultures (5/29, p< 0.001). Using the Jabalpur Prognostic Score, positive fungal cultures were found to be associated with a significantly higher than expected mortality. Patients with gastrointestinal perforations and positive peritoneal cultures have a poor prognosis, which is significantly worsened by the association of positive fungal cultures. Early recognition and treatment of fungal infection is advisable.     

Extended preservation of rat liver graft by induction of heme oxygenase-1

Livers can be preserved only for a short period without jeopardizing the transplantation outcome. Heat shock proteins (HSPs) protect against ischemia and reperfusion injury. We studied whether their induction and, in particular, the induction of heme oxygenase 1 (HO-1), improves transplantation survival after an extended time of cold storage. Rats were subjected to heat preconditioning (42 degrees C for 20 minutes). Livers were harvested 24 hours later, preserved in cold University of Wisconsin solution for 44 hours, and transplanted in isogeneic rats (arterialized transplantation). HO-1 was specifically induced and inhibited by cobalt protoporphyrin and tin protoporphyrin, respectively. All animals receiving a graft without preconditioning and subjected to 44 hours of cold preservation died within 3 days, whereas 89% of rats who received a graft exposed to heat survived for 3 weeks (P =.0004). Preconditioning reduced serum aspartate transaminase (AST) and lactate dehydrogenase activities after reperfusion, improved bile flow, and decreased the histologic lesions of reperfusion injury. These significant effects of heat preconditioning were prevented by administration of tin protoporphyrin and could be reproduced by administration of cobalt protoporphyrin. In grafts without preconditioning, only a small fraction (<5%) of hepatocytes were positive with the terminal deoxynucleotide transferase-mediated dUTP nick-end labeling (TUNEL) assay, and even less expressed activated caspase 3. Preconditioning tended to reduce the number of positive cells and to stimulate the expression of antiapoptotic Bcl-X(L). In conclusion, heat preconditioning and, specifically, overexpression of HO-1 improve posttransplantation survival and graft function after prolonged cold ischemia preservation. The mechanism underlying these beneficial effects does not appear to be prevention of apoptosis.     

Spontaneous bacterial peritonitis: a comparative study of 2 methods of ascitic fluid culture

The sensitivity in the diagnosis of spontaneous bacterial peritonitis of ascitic fluid inoculation in blood culture bottles has been compared with the conventional method. We have analyzed 74 positive ascitic fluid cultures from 64 patients, the samples being processed by both techniques simultaneously. While all the ascitic fluid cultures performed by inoculation in blood culture bottles were positive, in only 42 from the 74 conventional cultures (56, 75%) bacterial growth was detected (p less than 0.001). Nineteen bacterascites were diagnosed by inoculation in blood culture bottles and 10 by the conventional method (p = NS). Gram stain was only positive in 3 spontaneous bacterial peritonitis (6%). We conclude that ascitic fluid inoculation in blood culture bottles improves significantly the sensitivity of the microbiological diagnosis of spontaneous bacterial peritonitis, without increasing the diagnosis of bacterascites.     

Evaluation of suspected tuberculous pleurisy: clinical and diagnostic findings in HIV-1-positive and HIV-negative adults in Uganda.

SETTING: National Tuberculosis Treatment Centre, Mulago Hospital, Kampala, Uganda. OBJECTIVES: To compare clinical and radiographic presentation, and diagnostic methods, in adults with tuberculous pleurisy who are negative and positive for the human immunodeficiency virus (HIV). DESIGN: Adults with suspected pleural tuberculosis were screened by clinical examination, thoracocentesis and closed pleural biopsy. Biopsy material was cultured on Middlebrook 7H-10 solid medium and in BACTEC 12B radiometric vials. Pleural fluid was cultured using L?wenstein-Jensen slants, BACTEC and Kirchner liquid medium. RESULTS: Of 156 individuals enrolled, 142 had tuberculosis, of whom 80% were HIV-positive. Among those with tuberculosis, HIV-positive patients bad a more severe and longer illness. The size of effusions was similar in HIV-positive and HIV-negative patients. A higher proportion of HIV-positive patients had parenchymal infiltrates but this difference was not statistically significant. Pleural fluid lymphocytosis was present in all HIV-negative and 97% of the HIV-positive patients. HIV-positive patients had lower pleural fluid lymphocyte counts. Pleural fluid cultures were more often positive in HIV-positive patients. BACTEC and Kirchner liquid media gave higher yields than solid media. CONCLUSION: HIV-positive patients with tuberculous pleurisy had a more severe illness than HIV-negative patients. Mycobacterial cultures from HIV-positive patients were more often positive, suggesting more mycobacterial extension from the lungs into the pleural space. Liquid culture media were superior to solid media with regard to diagnostic yield and time until diagnosis.     

Graft ischemic time and outcome of lung transplantation: a multicenter analysis

RATIONALE: The effect of graft ischemic time on early graft function and long-term survival of patients who underwent lung transplantation remains controversial. Consequently, graft ischemic time has not been incorporated in the decision-making process at the time of graft acceptance. OBJECTIVES: To investigate the relationship between graft ischemic time and (1) early graft function and (2) long-term survival after lung transplantation. MEASUREMENTS AND MAIN RESULTS: The data from 752 patients who underwent single lung transplantation (n = 258), bilateral lung transplantation (n = 247), and heart-lung transplantation (n = 247) in seven French transplantation centers during a 12-year period were reviewed. Independent data quality control was done to ensure the quality of the collected variables. Mean graft ischemic time was 245.8 +/- 96.4 minutes (range 50-660). After adjustment on 11 potential confounders, graft ischemic time was associated with the recipient Pa(O2)/FI(O2) ratio recorded within the first 6 hours and with long-term survival in patients undergoing single or double lung transplantation but not in patients undergoing heart-lung transplantation. The relationship between graft ischemic time and survival appears to be of cubic form with a cutoff value of 330 minutes. These results were unaffected by the preservation fluid employed. CONCLUSIONS: The results of this large cohort of patients suggest a close relationship between graft ischemic time and both early gas exchange and long-term survival after single and double lung transplantation. Such relationship was not found in patients undergoing heart-lung transplantation. The expected graft ischemic time should be incorporated in the decision-making process at the time of graft acceptance.     

Contribution of a pleural antigen assay (Binax NOW) to the diagnosis of pneumococcal pneumonia

STUDY OBJECTIVES: To determine whether the detection of pneumococcal antigen in pleural fluid augments conventional microbiological methods used for the etiologic diagnosis of pneumonia. METHODS: In this retrospective study, a rapid immunochromatographic test (ICT) [NOW Streptococcus pneumoniae assay; Binax; Scarborough, ME] was performed on pleural fluid samples from 34 patients with pneumonia due to S pneumoniae, 89 patients with effusions of nonpneumococcal origin, and 17 patients with pneumonia of unknown etiology. Data on blood cultures, pleural fluid cultures, and urinary antigen tests were recorded. RESULTS: The ICT test result was positive in 24 of 34 patients (70.6%) with pneumococcal pneumonia and negative in 83 of 89 patients (93.3%) without pneumococcal pneumonia. The sensitivity of the pleural ICT test was higher than that obtained for blood (37.5%) and pleural fluid cultures (32.3%), but lower than the detection of pneumococcal antigen in urine samples (82.1%). However, three patients with pneumococcal pneumonia and a negative ICT urine test result had a positive pleural fluid antigen detection result test. Previous antibiotic exposure did not influence pneumococcal antigen detection in either pleural fluid or urine specimens. Six additional patients with empyema due to anaerobes (three patients), Streptococcus viridans (two patients), and Enterococcus faecalis (one patient) had false-positive pleural ICT test results. Finally, the ICT assay finding was also positive in 5 of 17 patients (29.4%) with pneumonia without a definite microbiological cause. CONCLUSIONS: The ICT test performed on pleural fluid samples augments the standard diagnostic methods of blood and pleural fluid cultures, even in the case of prior antibiotic therapy, and enhances the ICT urinary antigen assay.     

Bacterial arthritis: Are fever,rigors, leucocytosis and blood cultures of diagnostic value?

Summary Clinical suspicion, positive gram stains and cultures of the synovial fluid are the fundamental criteria for the diagnosis of bacterial arthritis. Bacterial arthritis may, however, show an oligosymptomatic clinical course and thus lead to a delay in diagnosis. The case records of 43 patients with bacterial arthritis were reviewed retrospectively. Rigors (20.9%), fever (40.5%), blood leucocytosis (41.8%) and a shift to the left of blood leucocytes (35%) were found in less than half of all examined patients. Positive cultures of the synovial fluid (71.4%) were far more frequent than positive blood cultures (23.5%). We conclude, that the absence of fever, rigors, blood leucocytosis and positive blood cultures does not rule out the possibility of bacterial arthritis.     

Donor-derived bacterial infections in lung transplant recipients in the era of multidrug resistance

ObjectivesOur aim was to analyze the prevalence of multidrug-resistant bacterial infections in lung transplant donors and to evaluate its influence on donor-derived bacterial infections.MethodsWe conducted a retrospective study of adult patients who underwent lung transplantation (2013–2016) at our hospital. Donor-derived bacterial infection was defined as the isolation of the same bacteria with identical antibiotic susceptibility patterns in the recipient and the perioperative cultures from the donor during the first month posttransplantation. We utilized a preventive antibiotic strategy adapted to the bacteria identified in donor cultures using systemic and nebulized antibiotics.Results252 lung transplant recipients and 243 donors were included. In 138/243 (56.8%) donors, one bacterial species was isolated from at least one sample; graft colonization (118/243; 48.6%), blood cultures (5/243; 2.1%) and the contamination of preservation fluids (56/243; 23%). Multidrug-resistant bacteria were isolated from 12/243 (4.9%) donors; four Enterobacterales, four Stenotrophomonas maltophilia, three Pseudomonas aeruginosa and one methicillin-resistant Staphylococcus aureus. There was no transmission of these multidrug-resistant bacteria. Donor-derived infections, primarily tracheobronchitis due to non-MDR bacteria, were diagnosed in 7/253 (2.9%) recipients, with good clinical outcomes.ConclusionsThe lungs of donors colonized with multidrug-resistant bacteria may be safely used when recipients receive prompt tailored antibiotic treatment.     

Usefulness of the British Thoracic Society and the American College of Chest Physicians guidelines in predicting pleural drainage of non-purulent parapneumonic effusions

AIM: To assess the value of the British Thoracic Society (BTS) and the American College of Chest Physicians (ACCP) guidelines to predict which patients with non-purulent parapneumonic effusions (PPE) warrant chest tube drainage. METHODS: A retrospective chart review was performed on all patients who underwent thoracentesis because of a PPE over a 10-year period at a Spanish medical center. Classification of PPE as complicated (CPPE) or uncomplicated (UPPE) was based on the clinician's decision to insert a chest tube to resolve the effusion. Empyema was defined as pus in the pleural space. Data collected included patient demographics, size of the effusion, and microbiological and pleural fluid chemistries that might influence the physician's decision to place a chest tube. RESULTS: Of the 240 patients with PPE who entered the study, 85 had UPPE, 67 had CPPE, and 88 had empyema. Individual pleural fluid parameters, namely a pH<7.20, a glucose<40 mg/dL or <60 mg/dL, a LDH>1000 U/L or a positive culture had a relatively high specificity (from 78% for LDH to 94% for glucose<40 mg/dL), but low to moderate sensitivity (from 25% for culture to 73% for LDH) in predicting the need for chest tube placement in non-purulent PPE. While pleural fluid cultures performed poorly in discriminating UPPE from CPPE (likelihood ratio positive 1.7), effusion's size performed the best (likelihood ratio positive 5.7). BTS and ACCP guidelines yielded measures of sensitivity (98% and 97%, respectively), and negative likelihood ratio (0.03 and 0.05, respectively) for identifying a CPPE. CONCLUSIONS: Both guidelines have similar accuracy and perform satisfactorily in distinguishing CPPE from UPPE, albeit at an admissible cost of needlessly increasing chest tube drainage.