Tissue plasminogen activator with prolonged dwell time effectively evacuates pleural effusions.

OBJECTIVES: Fibrinolytic therapy can be effective for management of complex pleural effusions. Tissue plasminogen activator (tPA, 10 mg) and deoxyribonuclease (DNAse) every 12 h with a dwell time of one hour is a common strategy based on published data. We used a simpler protocol of tPA (4 mg) without DNAse but with a longer dwell time of 12 h, repeated daily. We reviewed our results. METHODS: Charts were reviewed and demographics, clinical data and treatment information were abstracted. Outcomes were assessed based on radiographic findings and need for surgery. RESULTS: Two hundred and fifteen effusions in 207 patients (8 bilateral) were identified. 85% were either infectious or malignant. Two hundred and forty nine chest tubes were used: 84% were 10 Fr or 12 Fr and 7% were PleurX®. Five hundred and thirty one doses of tPA were given. The median number of doses per effusion was 2 (range 1-10), and 84% of effusions were treated with three or fewer doses. There were no significant bleeding complications. Median time to chest tube removal was 6 days (range 1 to 98, IQR 4 to 10). Drainage was considered complete for 78% of effusions, while 6% required decortication. CONCLUSIONS: Low dose tPA daily with a 12 h dwell time may be as effective as the standard regimen of tPA and DNAse twice daily with one hour dwell. For most patients only three doses were required, and small pigtail catheters were sufficient. This regimen uses less medication and is logistically much easier than the current standard.

Intrapleural Fibrinolytics and Deoxyribonuclease for Treatment of Indwelling Pleural Catheter-Related Pleural Infection: A Multi-Center Observational Study.

BACKGROUND: Indwelling pleural catheters (IPC) are increasingly used for management of recurrent (especially malignant) effusions. Pleural infection associated with IPC use remains a concern. Intrapleural therapy with tissue plasminogen activator (tPA) and deoxyribonuclease (DNase) significantly reduces surgical referrals in non-IPC pleural infection, but data on its use in IPC-related pleural infection are scarce. OBJECTIVE: To assess the safety and efficacy of intrapleural tPA and DNase in IPC-related pleural infection. METHODS: Patients with IPC-related pleural infection who received intrapleural tPA/DNase in five Australian and UK centers were identified from prospective databases. Outcomes on feasibility of intrapleural tPA/DNase delivery, its efficacy and safety were recorded. RESULTS: Thirty-nine IPC-related pleural infections (predominantly Staphylococcus aureus and gram-negative organisms) were treated in 38 patients; 87% had malignant effusions. In total, 195 doses (median 6 [IQR = 3-6]/patient) of tPA (2.5 mg-10 mg) and DNase (5 mg) were instilled. Most (94%) doses were delivered via IPCs using local protocols for non-IPC pleural infections. The mean volume of pleural fluid drained during the first 72 h of treatment was 3,073 (SD = 1,685) mL. Most (82%) patients were successfully treated and survived to hospital discharge without surgery; 7 required additional chest tubes or therapeutic aspiration. Three patients required thoracoscopic surgery. Pleurodesis developed post-infection in 23/32 of successfully treated patients. No major morbidity/mortality was associated with tPA/DNase. Four patients received blood transfusions; none had systemic or significant pleural bleeding. CONCLUSION: Treatment of IPC-related pleural infection with intrapleural tPA/DNase instillations via the IPC appears feasible and safe, usually without additional drainage procedures or surgery. Pleurodesis post-infection is common.

Encapsulated DNase improving the killing efficiency of antibiotics in staphylococcal biofilms.

We developed a polymer-encapsulated DNase, n(DNase), which can efficiently accumulate in biofilm and expose the DNase to cleave the eDNA of the biofilm. CLSM and crystal violet staining results demonstrated effective biofilm disintegration (92.2%) when treated with n(DNase). This work demonstrated a general approach for coating matrix-dispersion enzymes to achieve biofilm disintegration and provided a promising strategy for treating biofilm-associated infections.

Biological effect of tissue plasminogen activator (t-PA) and DNase intrapleural delivery in pleural infection patients.

Background: Pleural infection (PI) is a major global disease with an increasing incidence, and pleural fluid (PF) drainage is essential for the successful treatment. The MIST2 study demonstrated that intrapleural administration of tissue plasminogen activator (t-PA) and DNase, or t-PA alone increased the volume of drained PF. Mouse model studies have suggested that the volume increase is due to the interaction of the pleura with the t-PA via the monocyte chemoattractant protein 1 (MCP-1) pathway. We designed a study to determine the time frame of drained PF volume induction on intrapleural delivery of t-PA±DNase in humans, and to test the hypothesis that the induction is mediated by the MCP-1 pathway. Methods: Data and samples from the MIST2 study were used (210 PI patients randomised to receive for 3 days either: t-PA and DNase, t-PA and placebo, DNase and placebo or double placebo). PF MCP-1 levels were measured by ELISA. One-way and two-way analysis of variance (ANOVA) with Tukey's post hoc tests were used to estimate statistical significance. Pearson's correlation coefficient was used to assess linear correlation. Results: Intrapleural administration of t-PA±DNase stimulated a statistically significant rise in the volume of drained PF during the treatment period (days 1-3). No significant difference was detected between any groups during the post-treatment period (days 5-7). Intrapleural administration of t-PA increased MCP-1 PF levels during treatment; however, no statistically significant difference was detected between patients who received t-PA and those who did not. PF MCP-1 expression was not correlated to the drug given nor the volume of drained PF. Conclusions: We conclude that the PF volume drainage increment seen with the administration of t-PA does not appear to act solely via activation of the MCP-1 pathway.

The first use of combination of Intrapleural Fibrinolytics (Alteplase & DNAse) for pleural infection in Malaysia.

The use of a combination of intrapleural fibrinolytics or tissue plasminogen activator(tPA) Alteplase and deoxyribonuclease (Dnase) has been increasing for cases of complicated pleural infection/parapneumonic effusion worldwide. Its efficacy and success rate in selected cases of complicated parapneumonic effusion unresponsive to antibiotics and chest drainage are well documented. This case report demonstrates the first use of combination intrapleural fibrinolytic (Alteplase) and DNAse (Pulmozyme) in Malaysia for a case of pleural infection/parapneumonic effusion.

Alteplase and DNase for the treatment of pleural empyema in rats.

BACKGROUND AND OBJECTIVES: Adjunctive intrapleural fibrinolytic is an option to treat empyema at fibrinopurulent stage, but there is controversy about which should be use. Our objective is to evaluate the action of alteplase and/or desoxyribonuclease at physical and chemical properties in vitro pus derived from an experimental induced empyema in rats. METHODS: Streptococcus pneumoniae was introduced into the pleural cavity by thoracentesis through pleural pressure monitor. Animals were euthanized after 24 h, with macroscopic thoracic evaluation and measurement of amount of intrapleural liquid that was posteriorly stored at -80 °C. Selected samples were randomly distributed into four groups, then thawed at room temperature before exposure to one of the following: G1 = alteplase (n = 12), G2 = DNase (n = 12), G3 = alteplase + DNase (n = 12), or G4 = saline (n = 6). The mean molecular size in the fluid portion of the empyema was evaluated using dynamic light scattering; viscosity of the empyema fluid was measured using the drip method. RESULTS: Macroscopic showed purulent liquid, with fibrin and septation, with mean volume of 4.16 ml (0.5-8 ml). All samples were culture-positive for Streptococcus pneumoniae. Comparing with control, all experimental groups presented reduction of larger than 135 nm molecular size, but there was only significant difference with alteplase (p = 0,02). Viscosity reduced at all experimental groups, but increased at control. DNase group presented negative median (-5 mPa/s) of viscosity, and differed significantly from that observed in the control group (p = 0.04). CONCLUSIONS: Alteplase, DNase and alteplase + DNase changed significantly physical and chemical properties of experimental empyema at fibrinopurulent phase: alteplase reduced molecular size larger than 135 nm and DNase reduced viscosity.

M cell-targeting strategy enhances systemic and mucosal immune responses induced by oral administration of nuclease-producing L. lactis.

Efficient delivery of antigens to the gut-associated lymphoid tissue (GALT) is the most critical step for the induction of mucosal immunity by oral vaccines. As M cells are the main portal for luminal antigens into the GALT, the M cell-targeting of antigens affords a promising strategy toward the development of effective oral vaccines. Lactococcus lactis is a fascinating recombinant host for oral vaccines, as they survive and produce antigens in the gut and have a particularly safe profile for human use. In this study, we developed and evaluated an M cell-targeting oral immunization system using recombinant L. lactis strains. For the purpose, we generated an L. lactis strain that secretes a model antigen fused with the OmpH ß1α1 domain of Yersinia enterocolitica, which has been shown to bind to a complement C5a receptor on the M cell surface. As the model antigen, Staphylococcus aureus nuclease was used for fusion, resulting in L. lactis-expressing Nuc-OmpH (LL/Nuc-OmpH). Ex vivo intestinal loop assays showed that the amount of Nuc-OmpH taken up into Peyer's patches was more than that of the unfused nuclease (Nuc). In addition, oral administration of the recombinant L. lactis strains to mice demonstrated that LL/Nuc-OmpH-induced nuclease-specific fecal IgA and serum IgG titers were significantly higher than those induced by LL/Nuc. These results indicate that OmpH works as an M cell-targeting molecule when fused with antigens secreted from L. lactis and that the M cell-targeting strategy affords a promising platform for L. lactis-based mucosal immunization.

Concurrent Versus Sequential Intrapleural Instillation of Tissue Plasminogen Activator and Deoxyribonuclease for Pleural Infection.

BACKGROUND: Treatment of pleural infection with instillation of sequential intrapleural tissue plasminogen activator (tPA) and human recombinant deoxyribonuclease (DNase) twice daily for a total of 6 doses has been shown to decrease surgical referral and improve radiographic imaging. This labor-intensive regimen was empirically chosen. Thus, it remains unclear whether the 2 drugs can be administered immediately one after the other (concurrent administration) instead of instilling them separately with a 1-hour to 2-hour interval in between (sequential administration). The aim of this study was to compare the efficacy and safety of sequential versus concurrent tPA/DNase therapy in patients with pleural infection. METHODS: This was a prospective observational study. Consecutive patients with pleural infection who received concurrent and sequential tPA/DNase were included. The initiation and number of doses of tPA/DNase therapy were based on the amount of pleural fluid drainage, clinical response and radiographic findings. RESULTS: A total of 38 patients with pleural infection received tPA/DNase treatment: 18 in the sequential group and 20 in the concurrent group. Treatment was successful in 77.7% in the sequential group and 75% in concurrent group (P=0.57). There was no statistically significant difference between the 2 treatment groups (sequential and concurrent) in median pleural fluid drainage (P=0.45), median volume of pleural effusion estimated on chest computed tomography scan (P=0.4) or median hemithorax occupied by effusion on chest radiography (P=0.83) following intrapleural therapy. One patient required a blood transfusion for gradual pleural blood loss in each treatment group. Pain needing escalation of analgesia affected 3 patients in each arm but none required cessation of therapy. CONCLUSION: A simpler regimen of concurrent administration of intrapleural tPA/DNase as compared with sequential intrapleural therapy is safe, effective, and represents a viable option for the management of pleural infection.

Dose De-escalation of Intrapleural Tissue Plasminogen Activator Therapy for Pleural Infection. The Alteplase Dose Assessment for Pleural Infection Therapy Project.

RATIONALE: Intrapleural therapy with a combination of tissue plasminogen activator (tPA) 10 mg and DNase 5 mg administered twice daily has been shown in randomized and open-label studies to successfully manage over 90% of patients with pleural infection without surgery. Potential bleeding risks associated with intrapleural tPA and its costs remain important concerns. The aim of the ongoing Alteplase Dose Assessment for Pleural infection Therapy (ADAPT) project is to investigate the efficacy and safety of dose de-escalation for intrapleural tPA. The first of several planned studies is presented here. OBJECTIVES: To evaluate the efficacy and safety of a reduced starting dose regimen of 5 mg of tPA with 5 mg of DNase administered intrapleurally for pleural infection. METHODS: Consecutive patients with pleural infection at four participating centers in Australia, the United Kingdom, and New Zealand were included in this observational, open-label study. Treatment was initiated with tPA 5 mg and DNase 5 mg twice daily. Subsequent dose escalation was permitted at the discretion of the attending physician. Data relating to treatment success, radiological and systemic inflammatory changes (blood C-reactive protein), volume of fluid drained, length of hospital stay, and treatment complications were extracted retrospectively from the medical records. RESULTS: We evaluated 61 patients (41 males; age, 57 ± 16 yr). Most patients (n = 58 [93.4%]) were successfully treated without requiring surgery for pleural infection. Treatment success was corroborated by clearance of pleural opacities visualized by chest radiography (from 42% [interquartile range, 22-58] to 16% [8-31] of hemithorax; P < 0.001), increase in pleural fluid drainage (from 175 ml in the 24 h preceding treatment to 2,025 ml [interquartile range, 1,247-2,984] over 72 h of therapy; P < 0.05) and a reduction in blood C-reactive protein (P < 0.05). Seven patients (11.5%) had dose escalation of tPA to 10 mg. Three patients underwent surgery. Three patients (4.9%) received blood transfusions for gradual pleural blood loss; none were hemodynamically compromised. Pain requiring escalation of analgesia affected 36% of patients; none required cessation of therapy. CONCLUSIONS: These pilot data suggest that a starting dose of 5 mg of tPA administered intrapleurally twice daily in combination with 5 mg of DNase for the treatment of pleural infection is safe and effective. This regimen should be tested in future randomized controlled trials.

Deoxyribonuclease partially ameliorates thioacetamide-induced hepatorenal injury.

Several recent studies have shown that liver injury is associated with the release of DNA from hepatocytes. This DNA stimulates innate immunity and induces sterile inflammation, exacerbating liver damage. Similar mechanisms have been described for acute renal injury. Deoxyribonuclease degrades cell-free DNA and can potentially prevent some of the induced tissue damage. This study analyzed the effects of thioacetamide-induced hepatorenal injury on plasma DNA in rats. Plasma DNA of both nuclear and mitochondrial origin was higher in thioacetamide-treated animals. Administration of deoxyribonuclease resulted in a mild, nonsignificant decrease in total plasma DNA and plasma DNA of mitochondrial origin but not of nuclear origin. This was accompanied by a decrease in bilirubin, creatinine, and blood urea nitrogen as markers of renal function. In conclusion, the study confirmed the hepatotoxic and nephrotoxic effect of thioacetamide. The associated increase in cell-free DNA seems to be involved in hepatorenal pathogenesis because treatment with deoxyribonuclease resulted in a partial prevention of hepatorenal injury. Further experiments will focus on the effects of long-term treatment with deoxyribonuclease in other clinically more relevant models. Clinical studies should test endogenous deoxyribonuclease activity as a potential risk determinant for kidney or liver failure.NEW & NOTEWORTHY Thioacetamide-induced hepatorenal injury resulted in higher plasma cell-free DNA. Deoxyribonuclease decreased average cell-free DNA of mitochondrial origin but not nuclear origin. Deoxyribonuclease partially prevented hepatorenal injury in rats.

Safety and Efficacy of Tissue Plasminogen Activator and DNase for Complicated Pleural Effusions Secondary to Abdominal Pathology.

RATIONALE: Exudative pleural effusions may arise secondary to inflammation of intra-abdominal structures. Pleural space loculations can complicate these effusions, preventing adequate chest tube drainage and leading to consideration of surgical intervention. Previous studies have demonstrated that intrapleural administration of tissue plasminogen activator (tPA) combined with human recombinant DNase can improve fluid drainage and reduce surgery for patients with loculated parapneumonic effusions; however, the efficacy of this treatment has not been evaluated for complicated pleural effusions attributed to intra-abdominal inflammation. OBJECTIVES: We assessed the safety and efficacy of tPA/DNase for 17 pleural effusions associated with nonmalignant intra-abdominal pathology that did not drain adequately after placement of one or more chest tubes. METHODS: Efficacy was measured by comparing post- to pretreatment fluid drainage rates, volumetric assessment of pleural fluid on radiographic images before and after treatment, and clinical improvement, including the need for surgical intervention. Symptomatic relief was assessed using the Borg scale for breathlessness. MEASUREMENTS AND MAIN RESULTS: After a median of two doses of tPA/DNase, 23.5% of patients had chest pain and none had pleural bleeding. The volume of pleural fluid drained increased from a median of 325 ml to 890 ml per 24 hours after therapy (P = 0.018). The area of pleural space opacity on chest radiographs decreased from a median of 42.8-17.8% of the hemithorax (P = 0.001). tPA/DNase reduced the pleural fluid volume on chest computed tomographic imaging from a median of 294.4 ml to 116.1 ml. Borg scores improved from a median of 3 (interquartile range = 1-6) to 0 (interquartile range = 0-2) after therapy (P = 0.001). The median duration of chest tube placement and hospital stay were 4 and 11 days, respectively. Two patients required surgical intervention for lung entrapment. Overall, treatment was considered successful for 88.2% of patients. CONCLUSIONS: This retrospective case series suggests that intrapleural tPA/DNase can be safe and effective for patients with complicated pleural effusions attributed to abdominal pathology that do not drain adequately after chest tube placement. Additional studies are needed to determine whether the combination of tPA and DNase is more effective than tPA for this indication.

Mixing It Up: Coadministration of tPA/DNase in Complicated Parapneumonic Pleural Effusions and Empyema.

BACKGROUND: A recent randomized controlled trial showed 12 serial doses of tissue plasminogen activator (tPA) and deoxyribonuclease (DNase) is safe and effective in managing complicated parapneumonic pleural effusions and empyema (CPEE). However, this regimen is laborious, requiring trained personnel to open/close the chest tube 8 times daily for 3 days. We present our observational data using a simplified regimen of coadministered tPA/DNase. MATERIALS AND METHODS: This is a retrospective observational study of patients who received coadministered tPA/DNase for CPEE from January 2012 to April 2015 at the University of Texas Medical Branch. Patient demographics, pleural fluid, radiologic and treatment characteristics, and outcomes were collected. Data are presented as proportions and percentages. Our primary outcome was successful treatment without need of surgery and discharge home alive. Secondary outcomes were dose and length of treatment and hospital stay, treatment complications, and 90-day mortality. RESULTS: The study included 39 patients. All pleural effusions were loculated, 59% macroscopically purulent, 50% had a positive organism in Gram stain, and 40% were culture positive. A median of 6 (interquartile range, 3.5 to 6) doses were coadministered mainly via small bore chest tube (≤14 Fr in 79%) with a median of 14.5 (interquartile range, 9.5 to 21.5) hospital days. Overall, 85% were successfully treated without need for surgery. Treatment failures occurred in 15%: 3/39 (7%) received surgery; 3/39 (7%) died. Only 1 (2.5%) complication of hemorrhagic pleural effusion resolved after discontinuation of intrapleural treatment. CONCLUSIONS: Our study shows intrapleural coadministration of tPA/DNase was effective and safe in management of CPEE.

Safety and Efficacy of Intrapleural Tissue Plasminogen Activator and DNase during Extended Use in Complicated Pleural Space Infections.

The use of intrapleural therapy with tissue plasminogen activator and DNase improves outcomes in patients with complicated pleural space infections. However, little data exists for the use of combination intrapleural therapy after the initial dosing period of six doses. We sought to describe the safety profile and outcomes of intrapleural therapy beyond this standard dosing. A retrospective review of patients receiving intrapleural therapy with tissue plasminogen activator and DNase was performed at two institutions. We identified 101 patients from January 2013 to August 2015 receiving intrapleural therapy for complicated pleural space infection. The extended use of intrapleural tissue plasminogen activator and DNase therapy beyond six doses was utilized in 20% (20/101) of patients. The mean number of doses in those undergoing extended dosing was 9.8 (range of 7-16). Within the population studied there appears to be no statistically significant increased risk of complications, need for surgical referral, or outcome differences when comparing those receiving standard or extended dosing intrapleural therapy. Future prospective study of intrapleural therapy as an alternative option for patients who fail initial pleural drainage and are unable to tolerate/accept a surgical intervention appears a potential area of study.

Concurrent Intrapleural Instillation of Tissue Plasminogen Activator and DNase for Pleural Infection. A Single-Center Experience.

RATIONALE: Treatment of pleural infection with instillation of intrapleural tissue plasminogen activator (tPA) and human recombinant DNase (DNase) has been proven to decrease the length of hospital stay, decrease surgical referral, and improve drainage. The optimal dosage, administration, timing, and frequency of the regimen remain unclear. It is unknown if the two drugs can be administered immediately one after the other (referred to as concurrent) instead of instilling them separately with a 1- to -2-hour interval in between. OBJECTIVES: To assess the safety and efficacy of concurrent instillation of intrapleural tPA/DNase guided by radiographic and clinical response in patients with pleural infection. METHODS: We conducted a retrospective cohort study. Consecutive patients with pleural infection who received concurrent tPA/DNase were included. The initiation and number of doses of tPA/DNase therapy were based on pleural fluid drainage, clinical response, and radiographic findings. MEASUREMENTS AND MAIN RESULTS: Seventy-three patients received concurrent tPA/DNase therapy. Treatment was successful in 90.4% of them; 80.8% were effectively treated with fewer than six doses of therapy (median, 2; interquartile range [IQR], 1-3.5); and 71.2% received their first dose of tPA/DNase within 24 hours after chest tube insertion. The median hospital stay from the first dose of tPA/DNase to discharge was 7 days (IQR, 5-11 d). The volume of pleural fluid drained increased from a median of 295 ml (IQR, 97.5-520 ml) 24 hours before treatment to a median of 1,102 ml (IQR, 627-2,200 ml) 72 hours following therapy (P < 0.001). Nonfatal pleural bleeding occurred in 5.4%, 15.1% had chest pain, and 2.7% died as a result of pleural infection. CONCLUSIONS: This cohort study shows that early administration of concurrent tPA/DNase in patients with pleural infection is relatively safe and effective. Given the high cost of therapy, it is feasible to guide therapy on the basis of clinical and radiographic response.

Recombinant human deoxyribonuclease attenuates oxidative stress in a model of eosinophilic pulmonary response in mice.

The inflammatory cells infiltrating the airways produce several mediators, such as reactive oxygen species (ROS). ROS and the oxidant-antioxidant imbalance might play an important role in the modulation of airways inflammation. In order to avoid the undesirable effects of ROS, various endogenous antioxidant strategies have evolved, incorporating both enzymatic and non-enzymatic mechanisms. Recombinant human deoxyribonuclease (rhDNase) in clinical studies demonstrated a reduction in sputum viscosity, cleaving extracellular DNA in the airways, and facilitating mucus clearance, but an antioxidant effect was not studied so far. Therefore, we evaluated whether the administration of rhDNase improves oxidative stress in a murine model of asthma. Mice were sensitized by two subcutaneous injections of ovalbumin (OVA), on days 0 and 7, followed by three lung challenges with OVA on days 14, 15, and 16. On days 15 and 16, after 2 h of the challenge with OVA, mice received 1 mg/mL of rhDNase in the lungs. Bronchoalveolar lavage fluid and lung tissue were obtained on day 17, for inflammatory and oxidative stress analysis. We showed that rhDNase did not alter the population of inflammatory cells, such as eosinophil cells, in OVA-treated rhDNase group but significantly improved oxidative stress in lung tissue, by decreasing oxygen reactive species and increasing superoxide dismutase/catalase ratio, glutathione peroxidase activity, and thiol content. Our data provide the first evidence that rhDNase decreases some measures of oxidative stress and antioxidant status in a murine model of asthma, with a potential antioxidant effect to be further studied in human asthma.

Management of Intrapleural Sepsis with Once Daily Use of Tissue Plasminogen Activator and Deoxyribonuclease.

BACKGROUND: Pleural infection remains a significant cause of morbidity, mortality, prolonged hospital stay, and increased healthcare costs, despite advances in therapy. Twice daily intrapleural tissue plasminogen activator (tPA)/deoxyribonuclease (DNase) initiated at the time of diagnosis has been shown to significantly improve radiological outcomes and decrease the need for surgery. OBJECTIVES: To analyze our experience with once daily tPA/DNase for intrapleural sepsis. METHODS: Data derived from consecutive patients with empyema and complicated parapneumonic effusion who received once daily intrapleural tPA/DNase between January 2012 and August 2014 were reviewed. Measured outcomes included treatment success at 30 days, volume of pleural fluid drained, improvement in radiographic pleural opacity, length of hospital stay, need for surgery, and adverse events. RESULTS: 55 consecutive patients (33 male; mean age ± SD, 54.6 ± 16.1 years) were treated with once daily intrapleural tPA/DNase for 3 days. The majority of the patients (n = 51; 92.7%) were successfully managed without the need for surgical intervention. The mean change in pleural opacity measured on chest radiograph at day 7 was -28.8 ±17.6%. The median amount of fluid drained was 2,195 ml. No serious adverse events requiring discontinuation of intrapleural medications were observed. The most common complication was pain requiring escalating doses of analgesics (n = 8; 15%). Compliance with the protocol was excellent. CONCLUSION: Early administration of once daily intrapleural tPA/DNase for 3 days is safe, effective, and represents a viable option for the management of empyema and complicated parapneumonic effusion.

Delayed but not Early Treatment with DNase Reduces Organ Damage and Improves Outcome in a Murine Model of Sepsis.

Sepsis is characterized by systemic activation of coagulation and inflammation in response to microbial infection. Although cell-free DNA (cfDNA) released from activated neutrophils has antimicrobial properties, it may also exert harmful effects by activating coagulation and inflammation. The authors aimed to determine whether deoxyribonuclease (DNase) administration reduces cfDNA levels, attenuates coagulation and inflammation, suppresses organ damage, and improves outcome in a cecal ligation and puncture (CLP) model of polymicrobial sepsis. Healthy C57Bl/6 mice were subjected to CLP, a surgical procedure involving two punctures of the ligated cecum, or sham surgery (no ligation/puncture). Mice were given DNase or saline by intraperitoneal injection 2, 4, or 6 h after surgery. Two hours after treatment, organs were harvested and plasma levels of cfDNA, interleukin-6 (IL-6), IL-10, thrombin-antithrombin complexes, lung myeloperoxidase, creatinine, alanine transaminase, and bacterial load were quantified. Survival studies were also performed. The CLP-operated mice had rapid time-dependent elevations in cfDNA that correlated with elevations in IL-6, IL-10, and thrombin-antithrombin complexes and had organ damage in the lungs and kidneys. Administration of DNase at 2 h after CLP resulted in increased IL-6 and IL-10 levels and organ damage in the lungs and kidneys. In contrast, DNase administration at 4 or 6 h after CLP resulted in reduced cfDNA and IL-6 levels, increased IL-10, and suppressed organ damage and bacterial dissemination. Deoxyribonuclease administration every 6 h after CLP also rescued mice from death. Our studies are the first to demonstrate that delayed but not early administration of DNase may be protective in experimental sepsis.