Empyema with Dr. Shawn St. Peter

Mary Anne Jackson, an infectious disease physician, recommended the >10,000 white cell entry criterion for the trial, which initially seemed too soft but proved completely correct.

Empyema is defined by pleural fluid with greater than 10,000 white blood cells, which was the enrollment criterion used in the randomized trial.

When pleural fluid has >10,000 white cells and the patient undergoes VATS, the pleural space appearance is consistent with typical empyema.

The randomized trial at Children's Mercy compared primary VATS to primary fibrinolysis and found no difference in length of stay, with a 16% failure rate in the fibrinolysis group.

Patients do not get sicker with fibrinolysis, unlike VATS where barrel trauma to the good lung and manipulation of the bad lung can cause patients to 'fly pretty close to the treetop' postoperatively.

At Children's Mercy, the average duration of antibiotics was 25 days total with 19 days after becoming afebrile, and 40% of patients had complications from antibiotic therapy including diarrhea and fungal superinfections.

The current antibiotic protocol at Children's Mercy is 7 days after meeting three criteria: completed fibrinolysis, off oxygen, and afebrile. Antibiotics can be switched to oral if the patient is a candidate.

Recurrent empyema after successful treatment is extremely rare because the pleural space is typically obliterated (cemented space), making randomized trials of antibiotic duration unfeasible due to zero event rate.

Ultrasound has no disadvantage compared to CT for diagnosing empyema and identifying pleural stranding, and prospective studies show that placing ultrasound before CT decreases CT utilization without changing outcomes.

The TPA protocol is 4mg mixed in 40mL normal saline, instilled into a 12 French chest tube with 1-hour dwell time, repeated at 24 and 48 hours (three doses total over 48 hours).

Great Ormond Street published a study of 60 patients using urokinase with 4-hour dwell time that found identical results: no difference in length of stay and a 1 in 6 (approximately 16%) failure rate.

When comparing an operation to a non-operative approach, if results are equal, there is no way to recommend the operation and no parent would choose surgery when outcomes are the same.

A Spanish randomized trial of 100 patients using urokinase found no difference in length of stay and a 15% failure rate, consistent with prior studies.

Three randomized trials totaling 200 patients all show the same results: no difference in length of stay between VATS and fibrinolysis, with 15-16% failure rate for fibrinolysis.

In 100 consecutive patients treated with fibrinolysis after the trial, there was no difference in operative time or blood loss for patients who required subsequent VATS compared to primary VATS, contradicting concerns that fibrinolysis makes subsequent surgery more difficult.

Placing a 12 French chest tube under ultrasound guidance is less invasive and faster than placing a PICC line, taking less than a minute.

In older children who are not severely tachypneic, chest tube placement can be performed with local anesthetic alone without sedation.

Daily chest X-rays after fibrinolysis are not useful because the chest will look bad for quite a while even after completing treatment, and X-ray appearance does not help determine if fibrinolysis has failed.

Failure of fibrinolysis should be defined by persistent clinical illness (oxygen requirement, poor feeding) at 3-4 days after treatment, not by fever alone, since fever may be due to parenchymal disease.

A second round of fibrinolysis is only indicated when imaging shows a walled-off collection not in continuity with the initial chest tube placement; if the tube is well-positioned and there is persistent pleural disease in continuity with the tube, a second round is not recommended.

Extensive pulmonary necrosis is an absolute contraindication to surgical intervention because manipulating necrotic lung risks protracted bronchopleural fistulas requiring Heimlich valves for months.

Bronchopleural fistulas only occur when operating in a field of necrosis and debriding that necrosis; peripheral lung lesions heal without this complication.

During VATS for failed fibrinolysis, if the lung appears necrotic (black, necrotic-appearing), it should be left alone and only the pleural space should be debrided.

A patient with complete unilateral pulmonary necrosis who underwent needle biopsy died from exsanguination into the wound and bronchi, demonstrating that necrotic lung does not tolerate being touched.

A 3-year-old with bilateral pulmonary necrosis requiring VV ECMO for almost a month survived without surgical intervention and left the hospital without oxygen, demonstrating that necrotic lung heals with conservative management.

Well-defined peripheral pulmonary abscesses can be drained percutaneously with a drain left in place, but multifocal or complex abscesses should be managed conservatively like necrosis.

In the United States, TPA is the only available fibrinolytic agent for empyema since urokinase is not available and streptokinase has come off the market.

A randomized trial in adults suggested more rapid clearance by adding DNase to fibrinolytic therapy, but DNase is not approved for intrapleural use and requires an IND for pediatric study.