Restoring Air-Free Pleural Space in Pneumothorax

Selection among various management options in pneumothorax requires an understanding of the natural history of pneumothorax, the risk of recurrent pneumothorax, and the benefits and limitations of treatment options. Observation without oxygen, administering supplemental oxygen, simple aspiration, chest tube placement, video-assisted thoracoscopic surgery (VATS), open thoracotomy, and pleurodesis are among these options.

This article will briefly discuss the procedures for emergency needle decompression, needle aspiration, and tube thoracostomy.

Various considerations relate to the risks and benefits of the location of decompression tube placement and increasing use of pigtail catheters for tube thoracostomy. Specifically, the following are important:

• Awareness of the risk of incomplete penetration of the pigtail catheter to the pleural space with placement at the second intercostal midclavicular location, which is the Advanced Trauma Life Support (ATLS)-recommended site, as compared with the fifth intercostal midaxillary location, which is a secondary site under investigation
• Awareness of risk of tube kinking during patient transport using the fifth intercostal midaxillary location
• Awareness of increased opening pressure required at the fifth intercostal location as compared with the second

A 2017 Cochrane review compared the clinical efficacy and safety of simple aspiration versus intercostal tube drainage for management of primary spontaneous pneumothorax (PSP). ^[1] There was low- to moderate-quality evidence that tube drainage had higher immediate success rates, whereas simple aspiration was associated with shorter hospital stays. The two groups did not differ significantly with regard to early failure rate, 1-year success rate, or hospital admission rate, but the quality of the relevant evidence was not high.

In a systematic review and meta-analysis aimed at identifying the optimal initial intervention in adults with nontension spontaneous pneumothorax, Mummadi et al were unable to define a clear choice between a narrow-bore (< 14 French) chest tube (top-ranked in efficacy) and needle aspiration (top-ranked in safety). ^[2] Complications were more common with large-bore (≥14 French) chest-tube insertions than with needle aspiration.

Finger thoracostomy is sometimes employed as an alternative approach for prehospital decompression of pneumothorax, but additional studies are required to determine success rates and assess complications. ^[3]

Tension pneumothorax is a life-threatening condition that demands urgent management. If this diagnosis is suspected, do not delay treatment in the interest of confirming the diagnosis (ie, before radiologic evaluation) (see the images below).

This chest radiograph has 2 abnormalities: (1) tension pneumothorax and (2) potentially life-saving intervention delayed by waiting for x-ray results. Tension pneumothorax is clinical diagnosis requiring emergency needle decompression, and therapy should never be delayed for x-ray confirmation.

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Radiograph of patient with large spontaneous tension pneumothorax.

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Immediately place the patient on 100% oxygen, ventilate the patient if necessary, and evaluate the patient for evidence of respiratory compromise, hemodynamic instability, or clinical deterioration.

The basic principle for emergency needle decompression is to introduce a catheter into the pleural space, thus producing a pathway for the air to escape and relieving the built-up pressure. Although this procedure is not the definitive treatment for tension pneumothorax, emergency needle decompression does arrest its progression and serves to restore cardiopulmonary function slightly. Needle length in persons with large pectoral muscles may be an issue, and long needles or angiocatheters may be necessary. ^{[4, 5, 6, 7, 8]}

Essentially, a large-bore (16- or 18-gauge) angiocatheter is introduced in the midclavicular line at the second or third intercostal space. It is important to use large-bore catheters, because hemothorax can be associated with pneumothorax, and the patient may therefore require immediate intravenous (IV) infusion. Upright positioning, if not inappropriate because of cervical spine or trauma concerns, may be beneficial. This serves as a bridge until the definitive treatment of tube thoracostomy. The catheter is left in place until the chest tube is placed.

The procedure is as follows:

• Locate the anatomic landmarks, and quickly prepare the area to be punctured with an iodine-based solution
• Insert a large-bore needle with a catheter into the second intercostal space, just superior to the third rib at the midclavicular line, 1-2 cm from the sternal edge (ie, to avoid injury to the internal thoracic artery)
• Use a catheter or needle at least 5 cm long, and hold it perpendicular to the chest wall when inserting; however, note that some patients may have a chest-wall thickness greater than 5 cm, and failure for the symptoms to resolve may be attributed to inadequate needle length ^{[4, 5, 6, 7]} ; the use of longer angiocatheters (eg, 8 cm) has been advocated ^[7]
• Once the needle is in the pleural space, listen for the hissing sound of air escaping to confirm the diagnosis of tension pneumothorax (note this finding on the patient's chart); in an area with high ambient noise, the escape of air may not be detected
• Remove the needle while leaving the catheter in place
• Secure the catheter in place, and install a flutter valve

After needle decompression, immediately begin preparation to insert a thoracostomy tube. Then, reassess the patient, paying careful attention to the ABCs (ie, airway, breathing, circulation) of trauma management. An element of hemothorax along with the tension pneumothorax is common; therefore, the patient may require additional thoracostomy tubes.

Obtain a follow-up chest x-ray to assess for lung reexpansion, thoracostomy tube positioning, and to correct any mediastinum deviation (see the images below). Additionally, follow-up arterial blood gases (ABGs) may be ordered. Admit all patients with tension pneumothorax.

Radiograph of older man who was admitted to intensive care unit (ICU) postoperatively. Note right-side pneumothorax induced by incorrectly positioned small-bowel feeding tube in right-side bronchial tree. Marked depression of right hemidiaphragm is noted, and mediastinal shift is to left side, suggestive of tension pneumothorax. Endotracheal tube is in good position.

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Radiograph depicting right main-stem intubation that resulted in left-side tension pneumothorax, right mediastinal shift, deep sulcus sign, and subpulmonic pneumothorax.

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An alternative location for emergency needle decompression is via the fifth intercostal space on the midaxillary line. A 2011 cadaver study found that the success rate for needle entrance to the chest cavity approached 100%, whereas the second intercostal midclavicular location had only a 57.5% success rate. ^[9]

With the fifth midaxillary approach, there is a risk that a pigtail catheter may partially and temporarily occlude (11%), with a higher incidence than that of chest tube occlusion (4%). ^[10] Needle occlusion due to pigtail catheter kinking has been shown to be a risk of the fifth intercostal location in austere environments (eg, when military stretchers are used) and has an increased opening pressure (13.8 ± 3.6 mm Hg) as compared with the second intercostal location (7.9 ± 1.8 mm Hg). ^[11] The fifth intercostal location may be less suitable for overweight or obese patients who have greater chest-wall thickness at this location. ^[12]

Nonemergency needle aspiration can be used to treat a small PSP or an iatrogenic pneumothorax (see the images below).

Radiograph of patient with large spontaneous tension pneumothorax.

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Close radiographic view of patient with small spontaneous primary pneumothorax (same patient as in previous image).

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The procedure is as follows:

• Palpate the rib and intercostal space intended for needle aspiration; for needle aspiration, the anterior approach at the second or third intercostal space at the midclavicular line or a lateral approach at the fifth or sixth intercostal space at the midaxillary line is appropriate; for catheter aspiration, the lateral approach is preferred
• Prepare the skin with povidone-iodine, alcohol scrubs, or both, and cover with sterile drapes
• Instill a local anesthetic (eg, 1% lidocaine solution) to skin and soft tissue down to the pleura, directing the needle over the top of the rib into the desired intercostal space
• Insert a large-bore angiocatheter (14-gauge in an adult, 18- or 20-gauge in an infant) or ready-to-use aspiration kit into the chosen intercostal space over the top of the rib and perpendicular to the chest wall
• For simple needle aspiration, withdraw air once the pleural cavity is entered, and when resistance is felt, withdraw the needle
• For catheter aspiration, once the pleural cavity is entered, advance a soft pigtail catheter over the needle into the pleural space; a scalpel may be necessary to enlarge the entry site at the skin
• Remove the needle once the pleural cavity is entered, and attach the catheter to a three-way stopcock and large (eg, 60-mL) syringe to evacuate air
• When no more air can be aspirated (discontinue if resistance is felt, if the patient coughs excessively, or if more than 2.5 L is aspirated) or the patient suddenly coughs, the lung most likely has reexpanded
• Close the stopcock, and secure the catheter to the chest wall
• Obtain a chest radiograph to assess the degree of success, and obtain another radiograph 4 hours later to confirm the absence of recurring accumulation
• If no recurrence is present, remove the catheter and massage the insertion site with sterile gauze to seal the channel into the pleural space
• Discharge the patient with appropriate return instructions; some authors suggest observation for an additional 2 hours after catheter removal
• If the pneumothorax persists, attach a Heimlich valve or a water seal and admit the patient

Tube thoracostomy is the definitive treatment for secondary spontaneous pneumothorax (SSP) (see the image below) and tension pneumothorax. Needle decompression mandates an immediate follow up with a tube thoracostomy.

CT scan demonstrating blebs in patient with chronic obstructive pulmonary disease (COPD).

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Kulvatunyou et al performed a retrospective review of 9624 trauma patients of whom 94 were treated with pigtail catheters and 386 with chest tubes. The authors demonstrated a higher failure rate for pigtail catheters (11%) versus chest tubes (4%), but they pointed to the effectiveness of smaller tubes in many circumstances. ^[10]  Editorial comment accompanying the article pointed to the simplicity of pigtail catheter insertion and ease of instruction, which would allow insertion by "a gamut of healthcare professionals" to allow stabilization before transfer. Others have come to similar conclusions. ^[13] For this reason, both methods are summarized below.

Traditional tube thoracostomy

The procedure for traditional tube thoracostomy is as follows:

• If the patient is hemodynamically stable, consider conscious sedation with careful titration of a short-acting narcotic and benzodiazepine
• Place the patient in a 30-60° reverse Trendelenburg position
• Scrub the site (centered around the fifth or sixth rib in the midaxillary line) with povidone-iodine, alcohol, or both
• Locally anesthetize the site with lidocaine; use a generous amount, and anesthetize all the way down to the pleura
• Create a 3- to 4-cm horizontal incision over the fifth or sixth rib in the midaxillary line
• Use a curved hemostat, and dissect (in a controlled manner) through the soft tissue and down to the rib
• Push the hemostat just over the superior portion of the rib, avoiding the intercostal neurovascular bundle that runs under the inferior portion of the next most superior rib
• Puncture the intercostal muscles and parietal pleura; spread the hemostat wide to create an adequate opening
• Maintain the intrapleural position by inserting a finger along the side of the hemostat; assess the presence and location of pulmonary adhesions; sweep the finger in all directions, and feel for the diaphragm and possible intra-abdominal structures
• Remove the hemostat; to avoid losing the desired tract, some authors recommend keeping the finger in place until the tube is inserted
• Insert the chest tube over the finger into the pleural space; a clamp may suffice for guiding the thoracostomy tube into place on the proximal end
• Direct the chest tube posteriorly, and advance it until it is at least 5 cm beyond the last hole in the tube
• Look for condensation in the tube as a sign of correct placement and air evacuation
• Attach the tube to a water seal and vacuum device (eg, Pleur-Evac); look for respiratory variation of the water seal and bubbling of air through the water seal
• Document the amount of blood or other fluids drained
• Connect the thoracostomy tube to an underwater seal apparatus and suction.
• Suture the tube in place, dress the wound, and tape the tube to the chest
• Cover the site with Vaseline-impregnated gauze, and apply a suitable dressing; a variety of anchoring and closure techniques exist, all of which are probably equivalent
• Obtain a follow-up chest x-ray to assess tube positioning and lung reexpansion

Guidance and recommendations regarding tube placement in the setting of the COVID-19 pandemic are available from the American Association for the Surgery of Trauma (AAST). ^[14]

Pigtail catheter placement

Pigtail catheter placement requires attention to technical factors, as follows ^[10] :

• Keep the needle perpendicular over the rib, and barely advance the needle beyond the pleura; this maneuver avoids an inadvertent "too-far" advancement and a possible iatrogenic placement into a subclavian vein or through the diaphragm into the abdomen
• Always insert the needle over and not under the rib to avoid an intercostal artery injury
• In obese patients, a small incision and subsequent blunt dissection ensures identification of the rib
• The wire can easily be kinked during attempts to dilate the tract over the rib in thickly muscled patients; to avoid kinking of the guide wire, the dilator must be steadily and firmly advanced (but not forcefully pushed)

Surgical decompression (video-assisted thoracoscopic surgery [VATS], ^{[15, 16]} open thoracotomy, etc) is indicated for the following:

• Persistent air leak for longer than 5-7 days with a chest tube in place
• Recurrent, ipsilateral pneumothorax
• Contralateral or bilateral pneumothorax
• First-time presentation in a patient with a high-risk occupation (eg, diver, pilot)
• Patients with AIDS (often because of extensive underlying necrosis)
• Unacceptable risk of recurrent pneumothorax for patients with plans for extended stays at remote sites
• Lymphangiomyomatosis, a condition causing a high risk of pneumothorax ^[17]

(See Pneumothorax for more information.)

Potential complications associated with needle aspiration include pneumothorax (with potential for later tension pneumothorax), cardiac tamponade, hemorrhage (which can be life-threatening), loculated intrapleural hematoma, atelectasis, pneumonia, arterial air embolism (when needle thoracostomy is performed and no tension pneumothorax is present), and pain. Penetration of the myocardium is a rare but serious complication of needle thoracostomy. ^[18]

Complications of tube thoracostomy include death, injury to lung or mediastinum, hemorrhage (usually from intercostal artery injury), neurovascular bundle injury, infection, bronchopleural fistula, and subcutaneous or intraperitoneal tube placement.

An animal study showed a higher success rate with tube thoracostomy than with needle thoracostomy for both hemodynamic compromise or pulseless electrical activity resulting from pneumothorax. ^[19] In an adult swine model for traumatic pneumothorax, tube thoracostomy was successful 100% of the time in both conditions. In contrast, needle thoracostomy was only successful in 42% of hemodynamically compromised cases and 36% of pulseless electrical activity cases. Twenty-five percent of needle thoracostomy failures occurred within the first 5 minutes. When used as a rescue intervention after failed needle thoracostomy, tube thoracostomy restored perfusion in eight of nine cases.