Medical Chemistry Assignment By: Noor Al-Deen M. Al-Khanati

1

Chemical Pleurodesis Pleurodesis is a procedure that obliterates the pleural space in order to prevent recurrent pleural effusion or recurrent pneumothorax. It is most commonly performed by draining the effusion or intrapleural air and then instilling a chemical irritant into the pleural space, which induces inflammation and fibrosis. This is known as chemical pleurodesis. Common questions about chemical pleurodesis include:

• What are the indications for chemical pleurodesis? • What are the contraindications? • Which chemical irritant should be used?

Indications: Chemical pleurodesis has been used to manage malignant pleural effusions, refractory nonmalignant pleural effusions, and pneumothorax. Contraindications: Pleurodesis will certainly fail if the lung cannot fully expand (e.g. lung entrapment) because successful pleurodesis requires contact of the visceral and parietal pleura. Thus, chemical pleurodesis should not be attempted in this setting. Although there are no absolute contraindications to chemical pleurodesis, success is less likely in malignant pleural effusions when:

• Pleural fluid pH is lower than 7.20 or 7.30 • Glucose is less than 60 mg/dL • Lactate dehydrogenase is >600 U/L

Medical Chemistry Assignment By: Noor Al-Deen M. Al-Khanati

2

Choice of Agent: Numerous chemical irritants have been used to induce pleurodesis including: talc, tetracycline, minocycline, doxycycline, Corynebacterium parvum, fluorouracil, methylprednisolone acetate, bleomycin, interferon beta, mitomycin C, cisplatin, cytarabine, doxorubicin, etoposide, and Streptococcus pyogenes A3 (OK-432).

In a systematic review, talc was the chemical agent that most frequently resulted in complete success (no recurrence of pleural fluid). Numerous additional studies have confirmed that talc is the most effective agent for pleurodesis, including a large meta-analysis. Taken together, these studies indicate that successful pleurodesis occurs in greater than 90 percent of patients treated with talc.