Combination fibrinolytic therapy in the treatment of chronic septic pleuropneumonia in a Thoroughbred gelding

Pleural Empyema in Six Horses: A Retrospective Case Series

The clinical findings of pleural empyema in six horses were retrospectively studied using epidemiological, clinical pathology, microbiological, ultrasound, and post-mortem data. The clinical findings included tachycardia (n = 3/6), tachypnea (n = 6/6), cyanotic mucosa (n = 2/6), hyperthermia (n = 4/6), inspiratory or mixed dyspnea (n = 6/6), presence of fluid and/or pleural rubbing (n = 2/6) and coarse crackling on auscultation (n = 4/6). Horses demonstrated leukocytosis (16.22 × 103/µL) with neutrophilia (12.32 × 103/µL) and hyperfibrinogenemia (633.33 mg/dL) and an increase in urea (69.80 mg/kg) and globulins (5.22 g/dL). The pleural fluid exhibited exudate (n = 5/6). The pathogens isolated from transtracheal wash (TTW) and/or pleural effusion included Aspergillus fumigatus, Enterobacter cloacae, alpha and beta hemolytic Streptococcus, Pseudomonas aeruginosa, Salmonella sp., Streptococcus equi subsp. zooepidemicus, and beta hemolytic Staphylococcus. The in vitro tests of microbial sensitivity of the isolates revealed that ceftiofur (5/6) and penicillin (3/6) were the most effective drugs. The fatality rate was 83% (5/6). The main post-mortem finding was the presence of fibrin in the pleural cavity with adhesion between the parietal and visceral pleura. These results show that pleural empyema is a complex disease pathophysiology that is refractory to conventional treatment.

Loculations and Associated Risk Factors of Childhood Pleural Tuberculosis

Background: Pleural loculation in childhood pleural tuberculosis (TB) remains a problem in practice, it is usually associated with failure drainage. Therefore, to improve the management of childhood pleural TB, a retrospective study was conducted to identify the risk factors associated with loculated effusion in childhood pleural TB. Methods: Between January 2006 and December 2019, consecutive children (≤15 years old) with tuberculous pleural effusion (definite and possible) were included for further analysis. The demographic, clinical, laboratory, and radiographic features were collected from the medical records. Univariate and multivariate logistic regressions were used to explore the factors associated with the presence of pleural loculation in children with pleural TB. Results: A total of 154 children with pleural TB (definite, 123 cases; possible, 31 cases) were included in our study and then were classified as loculated effusion (n = 27) and non-loculated effusion (n = 127) groups by chest X-ray or ultrasonography. Multivariate analysis revealed that male gender (age-adjusted OR = 3.903, 95% CI: 1.201, 12.683), empyema (age-adjusted OR = 4.499, 95% CI: 1.597, 12.673), peripheral monocytes ≤0.46 × 10⁹/L (age-adjusted OR = 4.122, 95% CI: 1.518, 11.193) were associated with the presence of loculated effusion in children with pleural TB. Conclusion: In conclusion, several characteristics, such as male gender, empyema, and peripheral monocyte count have been identified as risk factors for pleural loculation in children with pleural TB. Our findings may be helpful to improve the management of pleural loculation in childhood pleural TB.

DIAGNOSIS AND MEDICAL AND SURGICAL MANAGEMENT OF CHRONIC INFECTIOUS FIBRINOUS PLEURITIS IN AN OKAPI (OKAPIA JOHNSTONI)

A 10-yr-old female okapi (Okapia johnstoni) at the San Diego Zoo Safari Park was evaluated for intermittent malaise, inappetence, occasional cough, abdominal splinting, and licking at both flanks. Physical examination revealed tachypnea, tachycardia, and fluid sounds on thoracic auscultation. Transthoracic ultrasound showed multiple uniform, anechoic filled structures in the right and left pleural space. Surgical exploration of the thoracic cavity revealed bilateral, mature, fibrous, compartmentalizing adhesions between the visceral and parietal pleura, confirming a diagnosis of chronic, infectious, fibrinous pleuritis. The suspected etiology was occult aspiration pneumonia secondary to historical episodes of regurgitation associated with general anesthesia. Culture of the pleural fluid and fibrous adhesions grew Trueperella (Arcanobacterium) pyogenes, Arcanobacterium haemolyticum, and few Fusobacterium species. Treatment consisted of chest-tube placement to establish drainage, thoracic lavage, unilateral surgical debridement, and long-term antibiotics. The animal made a complete clinical recovery over 7 mo.

The Association of Fibrinous Pleural Effusion with Survival and Complications in Horses with Pleuropneumonia (2002-2012): 74 Cases

BACKGROUND

Fibrinous parapneumonic pleural effusions are associated with decreased efficacy of pleural fluid drainage and increased risk of medical treatment failure in people, but similar associations have not been established in horses.

HYPOTHESIS/OBJECTIVES

We hypothesized that fibrin deposition in the pleural cavity of horses with parapneumonic effusions increases the risk of poor outcome.

ANIMALS

Seventy four horses with bacterial pleuropneumonia diagnosed by culture and cytology of tracheal aspirates, pleural fluid, or both, and pleural effusion diagnosed by ultrasonographic examination.

METHODS

Retrospective study of cases was from 2002 to 2012. Information obtained from the medical records included signalment, history, sonographic findings, treatments, and outcome. The primary outcome investigated was survival and secondary outcomes were development of complications and surgical intervention. Fisher's exact test and logistic regression were applied for categorical variables. A t-test was used to find differences in continuous variables between groups.

RESULTS

Seventy four horses met study criteria and 50 (68%) survived. Fibrinous pleural effusion was associated with higher respiratory rate and pleural fluid height at admission, necrotizing pneumonia, increased number of indwelling thoracic drains required for treatment, and decreased survival.

CONCLUSIONS AND CLINICAL IMPORTANCE

Fibrin accumulation in parapneumonic effusions is associated with increased mortality. Direct fibrinolytic treatment might be indicated in affected horses.

The Use of Recombinant Tissue Plasminogen Activator (rTPA) in The Treatment of Fibrinous Pleuropneumonia in Horses: 25 Cases (2007-2012)

Background

Information about treatment protocols, adverse effects and outcomes with intrapleural recombinant tissue plasminogen activator (rTPA) use in horses with fibrinous pleuropneumonia is limited.

Hypothesis/Objectives

Describe factors that contribute to clinical response and survival of horses treated with rTPA intrapleurally.

Animals

Horses with bacterial pneumonia and fibrinous pleural effusion diagnosed by ultrasonography, that were treated with rTPA intrapleurally.

Methods

Retrospective multicenter case series from 2007–2012. Signalment, history, clinical and laboratory evaluation, treatment, and outcome obtained from medical records. Regression analysis used to identify associations between treatments and outcomes.

Results

Thirty three hemithoraces were treated in 25 horses, with 55 separate treatments. Recombinant tissue plasminogen activator (375–20,000 μg/hemithorax) was administered 1–4 times. Sonographically visible reduction in fibrin mat thickness, loculations, fluid depth, or some combination of these was seen in 32/49 (65%) treatments. Response to at least 1 treatment was seen in 17/20 (85%) horses with sonographic follow‐up evaluation after every treatment. Earlier onset of rTPA treatment associated with increased survival odds. No association was found between cumulative rTPA dose or number of rTPA doses and survival, development of complications, duration of hospitalization or total charges. Clinical evidence of hypocoagulability or bleeding was not observed. Eighteen horses (72%) survived to discharge.

Conclusions and clinical importance

Treatment with rTPA appeared safe and resulted in variable changes in fibrin quantity and organization within the pleural space. Recombinant tissue plasminogen activator could be a useful adjunct to standard treatment of fibrinous pleuropneumonia, but optimal case selection and dosing regimen remain to be elucidated.

Pharmacokinetics and thrombolytic effects of the recombinant tissue-type plasminogen activator in horses

Background

To test the efficacy of the recombinant tissue-type plasminogen activator (rt-PA) alteplase in horses, the thrombolytic effect was tested in in vitro generated equine thrombi. The extent of lysis was determined by measuring the decrease in thrombi weight over a period of 4 hours. In vivo pharmacokinetics of alteplase were determined in 6 healthy horses. A single dose (1 mg/kg) was applied via intravenous infusion over a period of 30 minutes Coagulation-related variables, blood count and clinical parameters were taken before the treatment and until 48 h after treatment. In addition, plasma rt-PA concentration was measured until 300 min after commencing the infusion.

Results

In vitro, a dose dependent decrease of thrombus weight ranging from a 56 (± 6.5) % decrease for 0.5 μg/ml to 92 (± 2.1) % decrease for 5 μg/ml rt-PA was noted. The D-dimer concentration in the lysis medium correspondingly increased from 0.10 up to 10.8 mg/l.

In vivo, none of the horses showed an adverse reaction to the alteplase infusion. In some horses blood parameters were slightly altered. The 1 mg/kg dose yielded the following pharmacokinetic parameters: Cmax = 1.25 ± 0.27 μg/ml; CL = 21.46 ± 5.67 ml/min/kg; dominant half life (t1/2α) = 6.81 ± 1.48 minutes; median elimination half life (t1/2β) = 171 min (range: 85–1061); AUC = 50.33 ± 17.62 μg · min /ml.

Conclusion

These findings indicate that a single dose of 1 mg/kg alteplase results in rt-PA plasma concentrations comparable to those in humans and might be sufficient for a thrombolytic therapy in horses. Further studies must be performed to determine the alteplase effectiveness in horses with jugular vein thrombosis.