Chapter 94: Chest Tube Insertion

Tube thoracostomy is the procedure of insertion of a sterile tube or catheter into the pleural space. It is used to remove air and/or fluid to restore negative pressure to the pleural space. The various indications, diagnostic techniques, procedural approaches, and complications will be discussed in this chapter.

The pleural cavity is a closed space that exists between the visceral and the parietal pleura. The visceral and parietal pleura contain a single layer of mesothelial cells with multiple layers of connective tissue.¹ The parietal pleura is innervated by the intercostal nerves while the visceral pleura is not innervated. In a healthy individual, the mesothelial cells on the visceral pleura create a thin film of fluid that allows the pleura to glide smoothy during respiration. See Table 94–1 below for the characteristics of normal pleural fluid versus transudate and exudate.

Chest tube sizes are based on the external diameter, ranging from 6 to 40 French (Fr). Adult small bore chest tubes (SBCT) are tubes ≤ 14Fr. Chest tubes also come in a variety of shapes; the majority of chest tubes used in common practice are either straight, right angle, or pigtailed. Each tube has length markers to guide insertion and fenestrations for pleural drainage. Chest tubes can be “tunnelled” to decrease the rate of dislodgement and infection and to allow for long-term, outpatient management of pleural effusions. See Table 94–2 for a summary of choice of tubes based on indication.

When air or fluid enters the pleural space, drainage may be necessary based on the clinical condition of the patient.

Pneumothorax

Pneumothorax occurs when air enters into the pleural cavity. When a pneumothorax occurs unprovoked in a person without any underlying pathology, this is labeled primary spontaneous pneumothorax (PSP). Patients with a PSP can be managed in a number of ways based on their clinical picture and the size of the pneumothorax. To measure the size of a pneumothorax, computed tomography (CT) of the chest gives the most accurate 3-dimensional volume. CT is not always necessary, however, plain upright chest radiographs or bedside ultrasound are generally adequate for clinical decisions. The two most utilized methods of determining the size of a pneumothorax are by the American College of Chest Physicians (ACCP) and the British Thoracic Society (BTS). ACCP guidelines recommend measuring the distance from the outer edge of the pleural space to the most apical portion of the collapsed lung.³ Using this measurement, ≤ 3cm is considered small. BTS recommends measuring at the level of the hilum from the outer edge of the pleural space to the collapsed lung.⁴ According to BTS guidelines, a measurement < 2 cm is considered small.

For clinically stable patents with small pneumothoraces, recommended care includes observation for 3 to 6 hours followed by a repeat chest radiograph. If the repeat radiograph does not show progression of the pneumothorax, the patient can be safely discharged home and should return for a follow-up chest radiograph in 24 hours.^3,4,5,6 Uncomplicated pneumothoraces will reabsorb at a rate of 2% of the volume of the hemithorax every 24 hours.⁷ For patients with a large PSP or patients experiencing significant symptoms, needle aspiration or SBCT are the recommended treatments. In a study of 60 patients, needle aspiration and small bore catheters had similar failure rates but patients undergoing needle aspiration were hospitalized less.⁸ In addition, studies have demonstrated that small catheters are well tolerated and as effective as large bore chest tubes (LBCT).⁹ All individuals should have a follow-up within 2 to 4 weeks and avoid all air travel until full resolution of the pneumothorax is confirmed.

Secondary spontaneous pneumothorax (SSP), in contract to PSP, occurs in patients with underlying lung pathology. Patients with a SSP are likely to have worsened clinical symptoms than patients with a PSP. Patients with SSP should be admitted to the hospital and most will require intervention. SBCT have been found to be as effective as LBCT and are thus recommended.¹⁰ It is largely recommended that these patients be admitted but in some circumstances, patients may be discharged home with a Heimlich valve and follow-up within 2 days.³ If an air leak persists beyond 2 to 4 days, a thoracic surgeon should be consulted for consideration of further intervention.^3,4

Provoked or traumatic pneumothoraces can occur from blunt or penetrating injuries or from barotrauma. In the case of trauma victims, the number of pneumothoraces being identified has increased with the availability and ease of CT scanning and bedside ultrasonography. Many of these are considered occult pneumothoraces (OP), defined as a pneumothorax identified on CT or ultrasound, which was not suspected on the preceding chest radiographs. Most experts agree that OP in clinically stable patients can be managed conservatively with observation.^11,12,13,14 For patients with OP undergoing positive pressure ventilation (PPV), however, there remains controversy regarding whether or not to intervene. The traditional teaching was to perform tube thoracostomy on patients with occult pneumothorax if they were to undergo any period of PPV, including both prolonged mechanical ventilation during an ICU stay or for a limited time under general anesthesia.¹⁵ Recent literature, however, has shown that careful observation and directed intervention when needed of an OP may be safe and there is no difference in mortality or morbidity for these patients.^13,14,15,16 For patients chosen for tube thoracostomy, the historical teaching has also been to place a LBCT but recent literature has shown that in many situations, SBCT are considered safe and effective.¹⁷

The most feared complication of pneumothorax is that it will progress to tension physiology. Tension pneumothorax occurs when there is a disruption in the visceral or parietal pleural or tracheobronchial tree. A one-way valve forms, which allows air to flow into the pleural space with inhalation and prohibits air from flowing out. With each breath, the volume of air in the intrapleural space and pressure within the hemithorax increases. As the pressure increases, the ipsilateral lung collapses and causes hypoxemia. Eventually, the mediastinum will shift toward the contralateral side and impair the venous return to the heart, causing cardiovascular collapse. The treatment is immediate decompression. The historical treatment for a tension pneumothorax is immediate needle decompression in the second intercostal space at the midclavicular line and subsequent tube thoracostomy. However, many studies have shown that the suggested 14-gauge needle for needle decompression is not long enough to penetrate the chest wall in many patients at this location.¹⁸ Alternative approaches for needle decompression are at the fifth intercostal space in the anterior axillary line where the chest wall is generally thinner.¹⁹ Studies have also shown that needle decompression is associated with failure rates as high as 58%.²⁰ Despite this evidence, needle decompression is still recommended as first line treatment for tension pneumothorax followed by tube thoracostomy.

Hemothorax

Hemothorax is the accumulation of blood in the pleural space. Although the majority of hemothoraces occur as a result of trauma, some do occur in the ICU spontaneously. Also, they may arise as complications from procedures such as thoracentesis and central venous catheterization. These occur due to injuries to the intercostal or internal mammary arteries or pulmonary parenchyma. For traumatic hemothoraces, most surgeons recommend early (within 7 days) drainage of the hemothorax using large bore tubes (36F-42F). If the initial blood drainage is > 1500 mL or > 250 mL/h, surgery may be indicated. Complications such as fibrothorax and empyema can complicate hemothoraces that are not fully drained.

Pleural Effusion

Pleural effusions are abnormal, excessive fluid collections in the pleural space. The differential diagnosis of a pleural effusion is wide and occurs in many conditions, not exclusive to the thoracic cavity. For example, 20% of patients with pancreatitis have accompanying pleural effusion.²¹ Pleural effusions are divided into two types: transudative and exudative. Transudative effusions develop when systemic factors affecting the formation and absorption of the pleural fluid are altered, causing the pleural fluid to accumulate.²² Conditions where transudative effusions form are with increased interstitial fluid (heart failure), increased peritoneal fluid (cirrhosis), and decreased serum oncotic pressure (hypoproteinemia). Exudative effusions, conversely, develop due to the local alteration of the pleural surfaces or capillaries causing fluid to accumulate. The most common causes of exudative effusions are pleural malignancies, infection, and pulmonary embolism.

Traditionally, supine chest radiograph has been used in critically ill patients to identify acute processes such as pleural effusions. This modality, however, has a low sensitivity and specificity and can often miss large effusions. CT scanning is an excellent tool for identifying and characterizing lung, mediastinal, and pleural disease and quantifying the pleural fluid. Often, initial CT scanning has been replaced by bedside ultrasonography. This modality is noninvasive, low risk, and can be repeated as much as necessary. It can be used to evaluate the pleural space for fluid and often can characterize the complexity of the pleural space. In the hands of a trained user, it is highly sensitive and specific and can identify as little as 5 mL of pleural fluid.²³ Figure 94–1 shows ultrasound images of a simple versus complex pleural effusion. If a pleural effusion is identified and if clinically indicated, a thoracentesis and/or tube thoracostomy should be done guided by bedside ultrasonography. For patients with pleural effusion and continued respiratory compromise, drainage of pleural effusions has shown to lead to quick symptomatic improvement in many patients.²⁴

Pleural Infections

Parapneumonic effusions are any pleural effusion secondary to pneumonia or lung abscess.² Parapneumonic effusions represent a range of disease beginning with a dynamic, often self-resolving exudative effusion to a complex multiloculated fibrotic and often purulent collection to a thick pleural peal. Patients with pneumonia with an associated parapneumonic effusion have a higher morbidity and mortality than patients who have pneumonia without an effusion.²⁵ Although most simple parapneumonic effusions resolve with antibiotics, about 10% proceed to empyema and fail medical therapy.² When the effusion worsens, bacteria will cross the damaged endothelium and propagate pleural inflammation. Neutrophils then migrate into the pleural space and the coagulation cascade will be altered, decreasing fibrinolytic activity, causing septations to form within the fluid. Following this, fibroblasts will proliferate and a solid fibrous pleural peel will form over the lung and re-expansion is prevented, creating a persistent pleural space for continued infection.²⁶

For patients with parapneumonic effusions, the current recommendations are to perform a diagnostic thoracentesis to evaluate for empyema.²⁷ If the diagnostic testing reveals a fluid with a pH < 7.2, LDH > 1000, or a glucose < 60 mg/dL, drainage with tube thoracostomy may be indicated. For drainage of an empyema, LBCT are typically used because smaller pigtail catheters have a higher propensity for becoming clogged or dislodged.²⁸ For patients with continued symptoms, fibrinolytic enzymes may be attempted followed by consultation with a thoracic surgeon for resection and open drainage or decortication as indicated.

Chylothorax

Chylothorax is a collection of lymphatic fluid in the pleural space. This occurs due to malignancy, congenital abnormalities or injury to the thoracic duct or one of its main branches due to trauma or iatrogenically during a surgical procedure. Diagnosis is made by fluid analysis showing triglyceride level greater than 110 mg/dL or a cholesterol-to-triglyceride ratio of less than 1.²⁹ Treatment, again, depends on the clinical situation. Most patients require initial drainage due to the large volume (2-4 L/d) of chyle produced. Other strategies range from dietary restrictions to surgery.

When performing tube thoracostomy, landmark anatomy and bedside ultrasound is generally sufficient for placement. In some instances, however, CT mapping may be indicated. For example, patients with bullous lung disease may be misdiagnosed as a pneumothorax and tube thoracostomy in these patients may cause prolonged air leak from a bronchopleural fisula. For patients who have undergone procedures such as pleurodesis, pleurectomy, and previous thoracotomy, consider CT scanning prior to non-emergent tube thoracostomy to help with directing the tube.⁴ Also, patients who have had significant blunt abdominal trauma may be at risk for diaphragmatic injury and again, if the procedure is not emergent, further workup may be indicated.

Ultrasound is a valuable tool when evaluating the thoracic cavity for pathology as well as real-time direction during the procedure. A recent meta-analysis concluded that chest radiography is 39.8% sensitive and 99.3% specific in diagnosing pneumothorax whereas ultrasound is 78.6% sensitive and 98.4% specific.³⁰ For pleural effusions, ultrasound can help identify the size and characterization of the effusion and localize an area acceptable for tube thoracostomy. Whenever available, bedside ultrasound should be used to identify and map the thoracic anatomy and pathology.

Prior to attempting any procedure, it is advisable to review the patient’s previous imaging and laboratory results. Appropriate consent should be obtained, when possible. Benefits and risks should be discussed and possible complications should be explained. The patient should be properly pretreated for pain and anxiety associated with the procedure. All of the appropriate equipment should be gathered and a time out should be performed before beginning. See Table 94–3 for a list of common items required at the bedside.

For the mid-axillary approach, place the patient supine, in a position of comfort and place the ipsilateral arm above the head. The BTS guidelines recommend placement of the tube in the “safe triangle” consisting of the anterior border of the latissimus dorsi, the lateral border of the pectoralis major muscle, a line superior to the horizontal level of the nipple, and an apex below the axilla.³¹ Identify and mark the fourth and fifth intercostal spaces. For the mid-clavicular approach, place the patient supine, in a position of comfort. Identify and mark the second intercostal space at the mid-clavicular line.

Using sterile technique, prepare the area with either iodine or chlorhexadine. Infiltrate a 2 to 3 cm wheal one rib space below your mark with 1% lidocaine. Entering below and angling up will create a subcutaneous tunnel that will discourage air entry into the chest after removal of the tube. Angle the needle cephalad and infiltrate deeper tissues with the lidocaine, aspirating with each advance of the needle to avoid intravascular administration. Once the tip of the needle is over the chosen intercostal space being entered, angle the needle more perpendicular to the chest wall. Continue advancing the needle and anesthetizing until aspiration generates fluid or air, at which point the needle has entered the pleural space. Infuse the remaining lidocaine into the pleural space being careful not to exceed the subcutaneous toxic dose of lidocaine (3-5 mg/kg).

When entering into the thoracic cavity, you must pass first through skin and subcutaneous tissue then through three layers of muscle before entering the parietal pleura. Care must be taken to avoid the intercostal neurovascular bundle that runs inferior to each rib. Traditional teaching has been to place the tube just superior to the rib, however, recent studies show that the anatomy of the intercostal spaces is variable and the tube should be placed in the lower half to two-thirds of the intercostal space.³²

Blunt Dissection Technique

After the patient has been adequately anesthetized as above, make a 2 to 3 cm incision superior and parallel to the rib. Create a short tunnel using blunt dissection with Kelly clamps, following the previously anesthetized path. Once the parietal pleura is encountered, carefully push the closed clamps through the pleura; this may require some force. Once in the pleural space, do not advance more than 1 cm past the parietal pleura to avoid potential damage to the lung. Widen the pleural defect to accommodate the tube by spreading the clamps to create a defect approximately 1 to 2 cm long. This may cause a gush or air or fluid from the pleural space. Remove the clamps and insert a finger into the pleural space and explore the anatomy, feeling for the lung surface and adhesions. Loose adhesions may be broken, but avoid breaking strong adhesions since this may generate bleeding. Grasp the end of the chest tube with the clamp and gently guide the tube into the pleural space with a finger. Once the tube is in the pleural space, remove the clamp and advance the chest tube. For pneumothorax, advance the tube anteriorly and apically. For pleural effusions, aim the tube basally. Advance the tube until all side ports are within the pleural space. Attach the tube to the closed drainage system and secure into place.

Trocar Technique

This technique involves the use of a sharp tipped rod (trocar) that is inserted into the chest tube prior to placement. A skin incision is made similar to the blunt technique and the trocar/chest tube combination is pushed into the pleural space. Care must be taken not to advance the trocar more than 1 to 2 cm into the pleural space to avoid damage to the intrathoracic organs. The chest tube is then slid off the trocar and left in the pleural space. Since this technique has been associated with increased complication rate, it is generally not recommended for routine situations.

Seldinger Technique

An alternative, often less painful technique, is the Seldinger technique involving a guidewire and serial dilation. Techniques may vary slightly based on kit used. After anesthetizing the subcutaneous tissues as above, make an incision in the skin one rib space below the desired intercostal entry space. Make the incision large enough to accommodate the size of the chosen drain. Following the path of anesthetic, advance the introducer needle and syringe into the pleural space while continuously aspirating until air or fluid is aspirated without resistance. Do not advance the needle more than 1cm past the parietal pleura. Remove the syringe while anchoring the needle in the pleural space. Pass the guidewire through the needle hub and into the pleural space. The guidewire should pass freely without resistance. While holding the guidewire, remove the needle. Dilate the tract with the dilator(s) included in the kit. Only dilate to 1 cm past the parietal pleura. Advance the chest tube into the pleural space over the guidewire, ensuring that all side ports are within the pleural space. Some kits may include an introducer or trocar; pass these cautiously into the pleural space to avoid parenchymal damage. Remove the guidewire and introducer or trocar if included. Attach the tubing to the closed drainage device and secure the tube in place.

Securing the Tube

There are various methods of securing the tube at the site of insertion; none have been compared for failure or complication rate. Mattress sutures with securing ties are often utilized when securing LBCT. Purse string sutures are not recommended because they have been found to be painful and can cause additional scarring.³¹ Suture-free holding devices also exist. The tube should be secured to the drainage tubing with silk tape. The insertion site should be covered with sterile or petroleum gauze and taped securely to the patient. Avoid excessive taping or bandage because this may have a restrictive quality on the thoracic wall. Additionally, this may impede the speed that a malfunctioning tube can be evaluated.

Postplacement Management

After placing the tube, a chest radiograph or a lung/pleural ultrasound should be performed. Most chest tubes are designed with a radiopaque strip on the side of the tube to assist in visualization on chest radiographs. The sentinel eye is the most proximal side port; it will appear as a defect in the radiopaque strip. The sentinel eye should be located within the chest cavity.

The chest tube is connected to a closed drainage systems that acts as a one way valve to free air from the pleural space, collect any pleural fluid, and create negative pressure in the pleural space. Most drainage systems use three chambers based on previous three bottle systems. The first chamber is the collection chamber for any fluid drained from the plural space. For hemothorax, initial blood drainage of > 1500 mL or drainage of > 250 mL/h at any time requires emergent thoracic surgery consult and/or open thoracotomy. The second chamber is the water seal that acts as a one way valve. Air in the pleural space will appear as bubbles in the fluid; this is known as an air leak. When performing tube thoracostomy for pneumothorax, an air leak should be expected until the lung fully expands. If an air leak is persistent, surgical consultation may be required. The last chamber regulates the negative pressure being applied to the pleural space.

Frequent monitoring of the tube as well as the drainage system is required. The chamber should always be placed upright and should always be placed below the level of the patient. Monitor the fluid in the tubing for fluctuations during respiration or coughing, this indicates tube patency and placement in the pleural space. Cessation of this “tidaling” may indicate blockage or dislodgement of the tube.

Patients who develop excessive coughing, shortness of breath or chest pain as the pleural space is being drained may have re-expansion pulmonary edema. Temporarily stopping further drainage will be the best management.

Prophylactic antibiotics are recommended for trauma-related thoracic injuries requiring tube thoracostomy.³³ For patients with spontaneous pneumothorax or pleural effusions not related to an infection, antibiotics are not recommended.

Removal of Chest Tubes

Removal of a chest tube is usually a multifactorial decision based on the patient’s clinical condition and on the performance of the chest tube. Multiple studies have shown that chest tubes placed after surgery, for hemothorax and for pleural effusions can be safely removed when the drainage is less than 200 mL/d.³⁴ For pneumothorax, once there is no longer an air leak and the lung is fully expanded, the chest tube can safely be removed.³⁵ A step-wise practice can also be utilized by first taking the tube off of suction and placing the tube to water seal. If the patient is clinically stable, the tube can then be clamped. If the patient tolerates this and there is no change in chest radiograph, the chest tube can be safely removed. Clamping a chest tube once the air leak has resolved can often detect a small air leak not readily apparent at the bedside. Clamping of a chest tube with an active air leak is never recommended because of the potential for tension physiology to form.

When the clinician decides to remove a chest drain, the patient should be placed supine and in a position of comfort. The bandages should be removed and the sutures should be cut. The tube should be pulled out in one fluid movement. Traditionally, the teaching has been to pull the tube at end expiration or while the patient performs the valsalva maneuver to avoid recurrent pneumothorax. However, in a trial of removal of the tube during inspiration versus at end expiration while performing a valsalva maneuver, there were similar rates of recurrent pneumothorax.³⁶

Tube thoracostomy is a highly effective, and often life-saving technique but it is also associated with a complication rate as high as 30%u.³⁷ The most common complications include malposition, blockage, infection, dislodgement, re-expansion pulmonary edema, subcutaneous emphysema, nerve injuries, intrathoracic organ injuries, and residual pneumothorax. Less commonly, reports of esophageal perforation, cardiac injury, large vessel injury, chylothorax, fistula formation, and Horner syndrome have all been reported. Many of these complications can be avoided by adequate anxiolytics and analgesia, appropriate training and supervision, adequate technique and use of ultrasound guidance, and proper sterile technique. The most common complication is tube malposition where the tube is placed into somewhere other than the pleural space, including the lung parenchyma, lung fissures, into the chest wall, into the mediastinum, and into the abdomen.³⁷ The most common site of malposition is in the fissure and the greatest risk factor for this complication is lateral placement.

If fluid within the tube fails to fluctuate with coughing or respiration, the tube should be examined for a blockage or kinking tube. It is a common practice to milk or strip the tubes to clear the clot or debris. Although this practice is often effective in clearing the debris, this practice is controversial because it theoretically could cause damage to the lung tissue due to negative pressure.³⁷ Flushing with sterile saline every 6 to 8 hours can be considered as a method to prevent blockages.