Role of surgery in lung infection

Dr Arvind Kohli
Empyema is an accumulation of pus in the pleural space, the cavity between the lungs and the inner surface of the chest wall. Infection within the lung is  pneumonia whereas. Infection in the pleural space is called empyema which cannot be coughed out and must be drained by a needle or surgery. Sometimes called pyothorax or purulent pleuritis, empyema develops when bacteria invades the pleural space. A pleural effusion or “water on the lung” can develop into an empyema, a more serious and life-threatening condition. Empyema is typically caused by an infection such as pneumonia or following surgery.
Chronic infections of the lungs from pneumonia, tuberculosis, non-tuberculous mycobacterial (NTM) infections and influenza as well as fungal and bacterial infections can also be extremely serious, leading to pleural collections and subsequently Chronic empyema which are morbid for the patients
Risk Factors
Factors that put a person at risk for developing infections of the pleura (empyema) or infections of the lung include Pneumonia, Lung abscess ,Recent surgery or trauma to the chest. Chronic lung disease ,Elderly age group, Weakened immune system and Viral disease.
Empyema starts as thin infected tissue that prevents the lung from expanding. After a few days, this fluid becomes thick (gelatinous), and must be scraped out. If left inside, the gelatinous material turns to a scar on the lung like the peel of an orange. The last stage,fibrothorax, can cause permanent disability.
Signs and symptoms of empyema and lung infections
Patients who present with  Chest pain ,Dry cough Fever and chills Excessive sweating Shortness of breath Sharp or stabbing chest pain Loss of appetite, low energy, fatigue and Weight loss mustbe investigated to rule out pleural empyema.
Diagnosis of Empyema
* History and clinical signs are most important in establishing a diagnosis of pleural empyema .However  the  following diagnostic tests and procedures confirm the diagnosis and further line of management in these patients
Chest X-ray  is the basic investigations which reveals findings suggestive of pneumonia or pleural effusions However  these days Computed tomography scans CECT or High resolution CT scans(HRCT) are the main stay of establishing a diagnosis of Pleural Empyema
Ultrasound  around pleural cavity is a very useful adjuvant to Chest Xray to classify and quantify the amount of fluid present in pleural cavity or the shadow is because of thickened pleural membrane.
Diagnostic Thoracentesis,  a needle is inserted through the back of the ribcage into the pleural space to remove fluid and assess the fluid for its pathology and this procedure is called as Pleural fluid analysis
Treatment for Empyema and Lung Infection
The goal of treatment is to cure the infection by removing pus and affected tissue, draining the pleura so that the lung expands fully thereby reducing symptoms. Treatment methods include:
* Medical Treatment
Antibiotics are the mainstay of treatment keeping in view Pneumonia being the aetiology of Pleural collections ,Analysis of the fluid and its culture sensitivity guides to the organisms which are responsible for the infections and instituting appropriate antibiotics to which they are sensitive
*  Thoracocentesis . if the empyema is  early and collection is thin fluid  called as  transudate , A needle is inserted into the pleural space to drain fluidand the procedure is called Thoracocentesis. Aspiration of significant amount of fluid in many cases is therauptic
Intercostal Thoracostomy(ICTD): Placement of a tube into the pleural cavity through intercostal space under local anesthesia is a procedure for draining pus or fluid by Positioning the chest tube in a dependent part of the pleural effusion. Previously, large-bore (38-32F) tubes were recommended, but smaller tubes are similarly effective, and at least a 28F tube should be placed..
Smaller pigtail catheters (8-14F) can also be placed under ultrasound or CT guidance. These are considered  in smaller, difficult-to-access, multiple-loculated effusions and nonloculated, nonpurulent effusions. These catheters have also been successful in draining empyemas.
Continue closed-tube drainage as long as clinical and radiologic improvement are observed. The chest tube can be removed once the volume of the pleural drainage is less than 100 mL/24 h, with clearance of the pleural fluid turbidity seen in complicated pleural effusions.
If the patient does not demonstrate clinical or radiologic improvement with declining pleural fluid drainage, . a pleural space ultrasound examination or chest CT scanning is done to look for pleural fluid loculations and ensure proper tube placement.
Undrained pleural fluid may respond to intrapleural thrombolytic therapy or may require placement of another tube.
*Video-assisted thoracic surgery (VATS), a minimally invasive procedure that involves the insertion of a thoracoscope (a tiny camera) and surgical instruments into three small incisions without any spreading of the ribs. This operation is performed under anesthesia in the operating room. The surgeon is able to remove restricting tissue around the lung, insert a drainage tube or apply medicine(Sterile Talc) to reduce fluid accumulation.a procedure called pleurodesis
Thoracoscopy is an alternate therapy for multiloculated empyema thoracis. In patients with multiloculated parapneumonic pleural effusions, the loculations in the pleural space can be disrupted with a thoracoscope, and the pleural space can be drained completely. If extensive adhesions are present or thick pleural peel entraps the lung, the procedure may be converted to open thoracostomy and decortication.
*  Decortication, . Decortication is a surgical procedure that removes a restrictive layer of fibrous tissue overlying the lung, chest wall, and diaphragm. The aim of decortication is to remove this layer and allow the lung to reexpand. When the peel is removed, compliance in the chest wall returns, the lung is able to expand and deflate, and patient symptoms improve rapidly.
The results after decortication are often fruitful. The morbidity and mortality after a decortication is dependent on the patient age, underlying comorbidities, and development of complications from the surgery. Decortication in general has an excellent outcome in young people. However, when the procedure is done in patients with compromised lung function, the morbidity can be high. Besides surgery itself, the thoracic incision and general anesthesia also carry a high morbidity in people with no lung reserve
To avoid complications, the surgeon has to pay attention to detail. The peel should be removed with great care and injury to nearby organs should be avoided. If the decortication is done adequately, lung function improvement is remarkable. However, the ultimate return of lung function depends on preoperative lung disease.
Open thoracotomy and decortication was found to be an excellent surgical procedure with low morbidity and mortality. Functional results were also excellent, as all patients returned to the normal activities that they performed before surgery.
(The author is Thoracic Surgeon SSHGMC)