Immediate Drainage Is Not Required for All Patients with Complicated Parapneumonic Effusions*

Transcription

1 Immediate Drainage Is Not Required for All Patients with Complicated Parapneumonic Effusions* Herbert A. Berger; M.D.;t and Melvin L. Morganroth, M.D., F.C.C.P.t We retrospectively investigated if the clinical course of complicated parapneumonic effusions was altered by treatment with immediate drainage plus antibiotics vs antibiotics alone. The two groups of patients bad no signi6cant differences in age, duration of symptoms prior to hospitalization, initial maximum temperature, WBC count, or characteristics of the pleural ftuid. There were no differences in the duration of hospitalization, fever, elevated WBC count, intravenous antibiotic therapy, or the time for roentgenographic resolution of the effusions. There was one death in each group. The infection of the pleural space resolved in 13 of 16 patients treated with antibiotics alone. No recurrence of the infection of the pleural space occurred in these patients. Antibiotics alone were not sufgcient in two cases which eventually required chest tube drainage. Therefore, not all complicated parapneumonic effusions require drainage. A prospective study is required to determine if chest tube drainage should be part of the initial management of complicated parapneumonic effusions. (Chest 1990; 97:731-35) parapneumonic effusions are a common complication of bacterial pneumonia. The treatment required for parapneumonic effusions has been largely determined by the characteristics of the pleural Huid. Grossly purulent pleural ftuid (ie, empyema) requires drainage and does not resolve with antibiotic therapy alone. Pleural ftuid which neither is purulent, Gramstain positive, or culture-positive, nor has a ph less than 7.20 (ie, uncomplicated effusion), requires only antibiotic therapy and does not require drainage for resolution;2 however, the treatment required for nonpurulent pleural ftuid which either is Gram-stain positive or culture-positive or has a ph less than 7.20 (ie, complicated effusion) is controversial. Many physicians include immediate drainage in their treatment for these complicated effusions;3-6 however, at some medical centers, standard practice is to treat complicated parapneumonic effusions with antibiotics alone. 7 A prospective study comparing antibiotics vs antibiotics plus immediate drainage for complicated parapneumonic effusions has never been performed. The purpose of this preliminary retrospective study was to determine if antibiotic therapy alone can be sufficient treatment for complicated parapneumonic effusions. Case Selection MATERIALS AND METHODS One hundred sixty-one patients with parapneumonic effusions of any type (ie, empyema, complicated, or uncomplicated) were identified at the University of Michigan Medical Center from November 1977 to November All cases included had a febrile illness, purulent sputum, roentgenographic evidence for pulmonary infiltrates, and a pleural effusion. Cases were excluded because either no pleural fluid was obtained (n = 48), or the patient had a major underlying disease (primary lung cancer, 18; lung metastases, *From the Pulmonary and Critical Care Division, Department of Internal Medicine, University of Michigan, Ann Arbor. tresident in Internal Medicine. t&sistant Professor of Internal Medicine. &print requats: Dr. Morganroth, bubman, 1\Jmonary fhoilfon, Ann Arbor ; recent chest surgery including trauma, 7; collagen vascular disease, 7; pancreatitis, 3; and tuberculosis, 3). These latter patients were excluded from the study, since it would be difficult to determine if the persistence of pleural fluid was due to the underlying disease or to failure of treatment... Thus, 62 patients with characterized parapneumonic effusions without alternative causes for pulmonary infiltrates or pleural effusions were reviewed in this study. The retrospective approach was chosen in part due to the small number of cases available each year for study at our institution. Study Groups Each case was placed in one of three groups determined by the characteristics of the pleural fluid on the initial thoracocentesis. These three groups were empyema, complicated parapneumonic effusions, or uncomplicated parapneumonic effusions. "'Empyema"' was defined as grossly purulent pleural fluid. Complicated effusion was defined as pleural fluid with a ph less than 7.20, or positive Gram stain, or positive culture, but not grossly purulent. Uncomplicated effusion was defined as pleural fluid with a ph greater than 7.20, a negative Gram stain, and a negative culture. CUnical Course of Empyema and Complicated and Uncomplicated Effwions We determined if the clinical course of complicated parapneumonic effusions more closely fouowed the course of empyema, which required chest tube drainage, or of uncomplicated parapneumonic effusions, which do not require drainage. The clinical course was determined by the duration of hospitalization due to the primary pneumonia and parapneumonic drusion, the duration of temperature elevation above 38.1"C (0.5"F). the duration of elevated serum WBC count above,500/cu mm, with greater than 70 percent granulocytes, and the duration of intravenous antibiotic therapy. Because there has been some suggestion that complicated effusions secondary to Pneumococcus have a more benign course,..,. data were reexamined excluding infections secondary to Pneumococcus. CUnical Course of Complicated lbrapneumonic E.ffosWns Based on Initial ThuJtment We determined if the clinical outcome of complicated parapneumonic effusions was influenced by the initial treatment (intravenous antibiotics alone or immediate drainage plus antibiotics). Clinical outcome was determined by reviewing the duration of hospitalization, duration of elevated temperature, duration of elevated serum WBC count, duration of intravenous antibiotic use, and duration of CHEST I 97 I 3 I MARCH,

2 roentgenographic abnormality. ~ were able to analyze the data using this approach because at the University of Michigan Hospital, there is no clear consensus on the management of these patients. The decision for immediate chest tube drainage was at the discretion of the attending physician and his interpretation of the implications of the characteristics of the pleural fluid. To further determine if there was any significant difference in the initial clinical presentation of these two treatment groups in influencing the attending physician's decision for immediate chest tube drainage, the following clinical characteristics were compared: patient's age; initial maximum temperature; duration of symptoms prior to hospitalization; and initial size and composition of the pleural fluid. The size of the pleural effusion on the initial roentgenogram was determined by examination of the PA chest x- ray film and was quantitated as previously described." Briefly, "small" pleural effusions were defined as not extending above the dome of the hemidiaphragm. "Moderate" effusions were defined as extending above the dome of the hemidiaphragm but below the level of the hilum. "Large" effusions were those extending above the level of the hilum. Evidence of loculation was determined by ultrasound reports or lateral decubitus views on chest roentgenograms. Clinical Course of Complicated lbrapneumonic Effusions Treated with Antibiotics Alone All cases of complicated parapneumonic effusions initially treated with antibiotics alone were closely reviewed to determine if some patients eventually required drainage. Patients had at least three months of follow-up because delayed development of empyema three months following initial treatment with antibiotics alone has been reported. 3 Follow-up was obtained by reviewing the outpatient history and physical findings, chest roentgenograms, and telephone calls to determine if there was any recurrence of fevers, cough, shortness of breath, or hospitalization. Statistics Data were expressed as means ± SE. Comparison of means between groups was performed by using a one-way analysis of variance and the Newman-Keuls multiple range test. Categoric comparisons were performed using the x test or, where appropriate, Fisher's exact test. The p values were considered significant when less than REsuLTS Clinical Course of Empyema and Complicated and Uncomplicated Ibrapneumonic Effusions Of the 161 charts reviewed, there were 62 cases included in the study (Fig 1). There was no significant difference in the duration ofhospitalization or duration of elevated temperature in patients with complicated or uncomplicated parapneumonic effusions; however, FIGURE 2. Duration of hospitalization and fever for patients with empyema, complicated parapneumonic effusions, and uncomplicated parapneumonic effusions. Duration of hospitalization and fever are the same (p = NS) for complicated and uncomplicated effusions. Group with empyema had a significantly longer (p<0.05) duration. Asterisk indicates p<0.05 compared to group with empyema. (DAYS) EMPYEMA~ 111 CMfS Afi\IIEWEP + 62CASES PLEURAL FLUID] DATA AVAILABLE ~LNXlMPUCATED (13 CASES) PARAPNEUMONIC EFFUSIONS IMMEDIATE DRAINAGE (23 CASES) 3 DEATHS ANTIBIOTICS ONLY ODEATHS COMPUCATED PARAPNEUMONC EFFUSIONS (26CASES) /~ ANTIBIOTICS AND IMMEDIATE DRAINAGE INITIAL THERAPY WITH ANTIBIOTICS ( CASES) (16 CASES) 1 DEATH 1 DEATH FIGURE 1. Number of cases reviewed in each diagnostic group. the group with empyema had a significantly longer duration of fever and hospitalization than the other two groups (Fig 2). Similarly, there was a longer duration of elevated serum WBC count and duration of intravenous antibiotic therapy in patients with empyema, compared to those with complicated parapneumonic effusions (Fig 3). Thus, the clinical course of a complicated effusion more closely resembles that of an uncomplicated effusion. When comparing the groups of complicated vs uncomplicated effusions, excluding infections secondary to Pneumococcus, there was a significantly longer duration of hospitalization in the group with complicated effusions (p<0.05). The group with empyemas again had a significantly longer duration of hospitalization than the other two groups (Fig 4). The data were also reexamined for duration of elevated temperature. Again, the group with nonpneumococcal complicated effusions had a significantly longer (p<0.05) duration of fever (13 ± 1 days; n = 18) than the group with uncomplicated effusions (6 ± 1 days; n = 23). Thus, patients with complicated effusions not due to Pneumococcus had a more prolonged clinical course than patients with nonpneumococcal uncomplicated effusions. Clinical Course of Complicated Ibrapneumonic Effusions Based on Initial Treatment Close review from the medical records of the first , HOSPITALIZATION p<0.05 FEVER ~ EMPYEMA (na) COMPLICATED (n 24l UNCOMPLICATED (n IIMI8dlata Drainage Not Requlrad In All CIIMS of Parapneumonlc Effusions (Berg~ Motganroth)

3 50~ , p<o.os 30 (DAYS) 20 0 EMPYEMA (n=) II COMPLICATED (n=24) 0..._... woc, ELEVATION ANTIBIOTIC FIGURE 3. Duration of WBC count elevation and intravenous antibiotic therapy was significantly longer in group with empyema vs complicated parapneumonic effusions. p< OF HOSPITALIZATION 20 * FIGURE 4. Duration of hospitalization for patients with nonpneumococcal parapneumonic effusions. Nonpneumococcal complicated effusions had longer (p<o.os) duration of hospitalization than nonpneumoc-occal uncomplicated effusions. Asterisk indicates p<o.os compared to group with empyema. Table!-Initial Clinical Characteristics of Complicated Parapneumonic Effusion Treated with Antibiotics Alone vs Immediate Drainage Plus Antibiotics Intravenous Immediate Antibiotics Drainage Plus Data Alone Antibiotics Age, yr 46±6 51±7 (n= 16) (n= ) Duration of symptoms 6.5± ± 1.2 before hospitalization, (n= 16) (n= ) days Initial maximum 1.0± ±0.3 temperature, F (n= 16) (n= ) Initial Semm WBC 16,000± 1,000 15,000± 1,000 count per cu mm (n=16) (n= ) Pleural Ruid LDH, IUIL 2,600±600 1,900±900 (n=12) (n=6) Glucose, mgldl 62±21 74±25 (n= 12) (n=6) Protein, gldl 4.4± ±0.3 (n= 12) (n=8) WBCs per cu mm 49,000±27,000 60,000 ± 35,000 (n=13) (n=9) Size of pleural effusion, No. of patients Small 5 3 Medium 7 5 Large 4 2 Evidence ofloculation, No. of patients 4 (25%) 3 (30%) 0 -f---' ,.- EMPYEMA COMPLICATED UNCOMPLICATED (n=) (n=18) (n=23) few days of hospitalization revealed the initial treatment to be intravenous antibiotics alone in 16 patients and immediate drainage plus antibiotics in ten patients. In the ten cases receiving immediate drainage, seven had chest tubes placed immediately due to a positive Gram stain. The other three initially had a negative Gram stain, but chest tubes were placed within 24 hours of admission when the pleural fluid culture became positive. We found no significant difference in the initial clinical presentation of patients treated with antibiotics plus immediate drainage vs antibiotics alone (Table 1). The organisms infecting the pleural space did not differ in the two therapeutic groups. In the group treated initially with antibiotics alone, four of the pleural fluid cultures yielded Streptococcus pneumoniae, two Staphylococcus au reus, three Gram-negative rods, one anaerobes, and two mixed growth. In the group treated with immediate drainage plus antibiotics, two of the pleural fluid cultures yielded Strep pneumoniae, two Staph aureus, three Gram-negative rods, one anaerobes, and two mixed growth. In all cases of mixed growth, anaerobic organisms were cultured. The clinical outcome of complicated parapneumonic effusions in the two therapeutic groups showed no significant differences (Table 2). When the cost of hospitalization was adjusted for yearly increases, cost was higher (p<0.05) for patients treated with imme- CHEST I 97 I 3 I MARCH

4 Table 2-CUnical Outcome of Complicated lbrapneumonic Effwiona Treated with AntibioticB Alone va Immediate Drainage Plua AntibioticB Intravenous Immediate Antibiotics Drainage Plus Data Alone Antibiotics No. of patients 15* 9t Duration of hospitalization, days 16±1 22±3 Duration offever, days ±1 14±2 Elevated serum WBC, days ±1 16±2 Duration of antibiotics, days 15±1 19±3 Roentgenographic Resolution, days 44.3± ±8.0 *This excludes one patient who died on third day of therapy. tthis excludes one patient who died on fourth day of therapy. diate drainage plus antibiotics ($19,900 ± $1, 0; n = 9), compared to antibiotics alone ($15,800 ± $700; n= 14). Clinical Course of Complicated lhrapneumonic Effusions Treated with Antibiotics Alone All16 cases of complicated parapneumonic effusions treated with antibiotics alone were closely reviewed. There was one death in an 88-year-old patient with a pneumococcal pneumonia. He refused aggressive therapy. The follow-up period for all 15 remaining patients was greater than three months (mean, 16.5 ± 3.5 months). Two patients eventually required chest tube drainage during the initial hospitalization due to persistent fever, leukocytosis, and persistently positive fluid cultures. Both patients had Gram-negative rod pneumonias requiring 11 and 14 days of drainage; however, neither required open thoracotomy for resolution. Nine patients treated initially with antibiotics alone had a pleural fluid ph correctly obtained. Four patients had a ph less than Two patients with a pleural fluid ph less than 7.00 had a pneumococcal pneumonia; neither required chest tube drainage. One patient with a pleural fluid ph of and a positive culture for a Gram-negative rod eventually required chest tube drainage for persistent effusions. Another patient with a pleural fluid ph of 6.81 and a negative culture and Gram stain improved with antibiotics alone. The condition of five patients whose pleural fluid ph ranged from 7.00 to 7.20 improved with antibiotic therapy alone. DISCUSSION The major finding of our retrospective study was that antibiotic therapy without chest tube drainage was sufficient for most of our patients with complicated parapneumonic effusions. The initial response to therapy and the long-term outcome were not different in patients treated with antibiotics alone or antibiotics plus immediate chest tube drainage. Although delayed empyema formation has been reported up to three months following treatment with antibiotics alone for complicated parapneumonic effusions, 3 none of our 13 patients whose condition responded to antibiotic therapy had a delayed recurrence of their infection of the pleural space. There has also been concern that delay in draining complicated parapneumonic effusions would result in empyema formation and the inability to drain the effusion with a chest tube Two patients with Gramnegative rod pneumonias had failure of initial therapy with antibiotics alone; however, both of these patients were successfully drained with chest tubes and did not require thoracotomy. Therefore, antibiotics alone are not sufficient therapy for all patients with complicated parapneumonic effusions. It is possible that these two patients would have had a shorter hospitalization if the effusion had been immediately drained. Furthermore, given larger numbers of patients, it is likely that some patients who received delayed drainage might have required rib resection and decortication for resolution of the infection of the pleural space. Our results were not explained by a difference in the presenting clinical characteristics of patients treated with antibiotics alone or with antibiotics plus immediate drainage. Prolonged duration of symptoms before hospitalization, the size of the pleural effusion, and the presence ofloculated fluid have been reported to affect the outcome in patients with complicated parapneumonic effusions; however, none of these factors was different in our two groups. Low glucose levels and ph of the pleural fluid have been reported to be markers of severe pleural fluid inflammation. In our study, glucose concentrations were similar in both therapeutic groups. In our study, only a few patients had the ph of the pleural fluid carefully obtained, and thus insufficient data are available to compare our two therapeutic groups based on this measurement; however, three of four patients with pleural fluid ph less than 7.00 were successfully treated with antibiotics alone. The fourth had failure of antibiotic therapy and required drainage. Thus, patients with complicated effusions with a ph less than 7.00 were present in the group treated with antibiotics alone. The types of organisms responsible for the bacterial pneumonia and infected pleural space have been shown to affect the clinical course. Patients with anaerobic infections have a longer duration of symptoms prior to hospitalization. 12 The percentage of anaerobic bacteria growing from the pleural fluid in our study was similar to the report by Varkey et al13 on parapneumonic effusions and was not different in our two therapeutic groups. There has been some suggestion that complicated parapneumonic effusions 734 lmmeclate Drainage Not Requirad In All Casas of Parapneumonlc Effualons (~ Morgemoth}

5 secondary to Strep pneumoniae has a more benign clinical course. Thryle et al reported three cases with positive pleural Huid cultures for Strep pneumoniae whose infections resolved with antibiotic therapy. Light et al 2 studied 153 patients with pneumococcal pneumonia, of which 61 had evidence of pleural Huid. One of these cases had a pleural Huid ph of 7.20, which improved with antibiotic therapy. Only two of the 61 patients with evidence of pleural Huid required drainage. Although our study indicated that patients with pneumococcal complicated effusions had a shorter clinical course, these patients represented a minority of our patients and do not explain our results. Since there was no significant difference in the two therapeutic groups, the greatest inhuence on the clinical outcome would appear to be determined by the initial treatment; however, given the retrospective nature of our study, we cannot exclude that factors not examined could have inftuenced the outcome of our patients. To further analyze the need for immediate drainage in complicated parapneumonic effusions, we combined our data with cases previously reported. In 1976, Potts et al 5 reported seven cases of complicated parapneumonic effusions. The clinical course of two of the seven cases was presented. One patient's pleural Huid became loculated and eventually required decortication for improvement. Another patient, while on antibiotic therapy alone, developed a positive pleural Huid Gram stain and culture. This patient's condition eventually improved with drainage. The other five patients all received early chest tube drainage without mention of whether conservative therapy had been tried first. In 1973, Ught et al3 reported five cases with complicated parapneumonic effusions. Three of these patients were treated with antibiotics alone and died. The fourth patient's condition improved after chest tube drainage, but there was prolonged hospitalization. The fifth patient was initially discharged but was readmitted three months later with empyema. In another study, Light et al 2 described II patients with complicated effusions. Four of these patients had a pleural Huid ph between 7. and 7.20 but were negative on Gram stain and culture. The condition of all four of these patients improved with antibiotic therapy alone. Another patient had a positive pleural Huid culture for Strep pyogenes and a ph of7.20. This patient's pneumonitis and pleural disease "resolved without undue delay" with antibiotic therapy alone. In the remaining six patients, little discussion was given to the clinical course of the complicated effusion prior to surgical drainage. None of these reports clearly compared the clinical course following antibiotic therapy alone vs immediate drainage. Reviewing our data, in addition to the previously mentioned literature, reveals 28 patients with complicated effusions being treated initially with antibiotics alone. Four patients died before further aggressive therapy was begun. The condition of six patients improved only after drainage was employed. Eighteen patients continued to improve with antibiotic therapy alone. Clearly, some patients with complicated parapneumonic effusions can be treated with antibiotics alone. Using the characteristics of the pleural Huid alone in determining the need for drainage in patients with complicated parapneumonic effusions may result in patients receiving drainage unnecessarily; however, insufficient data are present to determine if delay in draining complicated parapneumonic effusions in patients who eventually require drainage will result in a significantly longer hospitalization and increase the need for surgical drainage, rather than placing a single chest tube, to successfully treat the infection of the pleural space. Undoubtedly, some of the patients presented in the prior studies benefited from early chest tube drainage. A prospective randomized study will be required to determine if conservative therapy (ie, antibiotics alone) for patients with complicated parapneumonic effusions results in an unacceptable number of patients who require surgical drainage and a prolonged hospitalization for resolution of the infection of their pleural space. 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