Alternative Treatments of Pneumothorax

Zachary D. Repanshek, MD; Jacob W. Ufberg, MD; Gary M. Vilke, MD; Theodore C. Chan, MD; Richard A. Harrigan, MD

Disclosures

J Emerg Med. 2013;44(2):457-466. 

In This Article

Discussion

Estimation of Pneumothorax Size

To determine the most appropriate management, it may be necessary to first obtain a reasonable estimation of the size of the pneumothorax. The most definitive way of measuring pneumothorax size is by three-dimensional volume measurement using computed tomography (CT) imaging. However, in most cases of pneumothorax, CT imaging is not indicated or necessary, as it will likely not change management.[5,6] Therefore, routine estimation of pneumothorax size is often done using plain films. The American College of Chest Physicians' (ACCP) definition of small (<3 cm) or large (≥3 cm) pneumothorax is based on a simple measurement of distance from the outer edge of the pleural space to the most apical portion of the collapsed lung. The British Thoracic Society (BTS) uses the greatest distance from the outer edge of the pleural space to the collapsed lung at the hilum to define small (<2 cm) and large (≥2 cm).

To determine pneumothorax size as a percentage of lung volume lost, the BTS uses a more complex equation that estimates the volume of both the lung and the hemithorax using the largest diameter measurement of both the collapsed lung and the hemithorax, cubing these diameters (because the volume of the lung and the hemithorax are roughly proportional to the cube of their diameters), and finding the ratios.[7]

Two other methods of measuring pneumothorax size as a percentage of lung volume lost utilizing chest radiography are the Rhea method and the Collins method.[8,9] In both methods, the distance of the pleural space is measured at the apex, midpoint of the upper half of the lung, and midpoint of the lower half of the lung on upright chest radiography to estimate pneumothorax size by percent by using a nomogram. The Rhea method utilizes the "average interpleural distance," whereas the Collins method uses the sum of these distances (Table 1). Although head-to-head studies have shown agreement between these two methods in smaller pneumothoraces, Collins' method seems to be more accurate in large pneumothoraces(10).

Treatment

Observation. There has been controversy as to whether any pneumothorax should be left untreated. Only two professional bodies have reported guidelines on this subject matter in the past 10 years. A report by the BTS in 2003 recommends observation of small (described as < 2 cm), closed PSP with minimal symptoms.[5] These recommendations were based on studies showing good outcomes with conservative management, with resolution rates in the range of 70–80%.[11,12] An updated version of the BTS guidelines in 2010 reiterated these same recommendations, but also added that select asymptomatic patients with large PSP may be managed by observation alone as well, but did not further clarify selection criteria.[13] In a 2001 consensus statement, the ACCP came to the agreement that a clinically stable patient with a small PSP (< 3 cm) may be observed for 3–6 h and discharged if a repeat chest radiograph shows no progression of the pneumothorax.[6] It has also been shown that observation alone may be appropriate for patients with a reduction of < 15% of lung volume, and that there is a decrease in pneumothorax recurrence in these patients with this strategy when compared with treatment by tube thoracostomy.[12] Although observation may be indicated in patients with PSP, it is contraindicated in patients with any underlying lung pathology, including secondary spontaneous pneumothorax (SSP), traumatic pneumothorax, tension, or signs of clinical instability.

The risk for treating PSP with observation is recurrence and progression, potentially resulting in tension pneumothorax. Patients failing this form of management most often require treatment with tube thoracostomy. The obvious advantage of conservative management is avoiding the risks and complications of a procedure, as well as decreased cost and avoidance of hospital-associated complications if the patient can be discharged. Whereas the ACCP suggests discharge only after 3–6 h of observation and a repeat film showing no progression, the BTS gives no specific discharge criteria other than "not associated with breathlessness," nor does it make mention of repeat imaging in the ED. In all cases, discharge with observation alone is contingent on the ability of the patient to have close follow-up, and appropriate instructions must be given for immediate return if symptoms worsen. The ACCP consensus recommends follow-up for repeat chest radiography within 12–48 h after discharge. The BTS suggests "early outpatient review" and return for a follow-up chest radiograph after 2 weeks. Both bodies recommend admission for observation for patients without reliable follow-up.[5,6]

We recommend that observation be used as first-line treatment for small PSP in a stable patient without shortness of breath at rest. For the purposes of this article, pneumothoraces will be defined as either small (<3 cm) or large (≥3 cm), based on the distance from the outer edge of the pleural space to the most apical portion of the collapsed lung. These patients should be observed in the ED for a minimum of 3 h before having repeat chest radiography done. If improvement or no progression is shown, the patient may be discharged if able to have reliable follow-up within 48 h.

Simple Aspiration. Simple aspiration is a less invasive technique than tube thoracostomy that has been shown to be an effective alternative in certain situations, decreasing the risk of complications, and minimizing patient discomfort, as well as shortening length of stay and perhaps eliminating the need for hospital admission altogether (Table 2). Like observation, simple aspiration is indicated in patients with stable, closed PSP. A history of trauma or any signs of tension or clinical instability are contraindications to simple aspiration. Underlying lung disease is a relative contraindication to this technique.

Simple aspiration is performed, using sterile technique, by inserting a 16-gauge needle attached to a 60-mL syringe with a 3-way stopcock into the patient's midclavicular second intercostal space, the midaxillary fourth or fifth intercostal space, or posteriorly beneath the scapular edge(14). Alternatively, a 16-gauge catheter-over-a-needle may be used in a manner similar to needle decompression. Once the needle has entered the pleural space, it may be removed and the stopcock and syringe are connected to the catheter. This technique may be preferred due to the theoretical risk of lung injury from the needle on re-expansion, whereas inserting a needle with a syringe attached has the advantage of real-time aspiration of air being used to signify entering the pleural space.

Once either the needle or catheter is connected to the syringe and stopcock, air is aspirated in 60-mL increments, closing the stopcock between each aspiration and expelling the collected air, until lung re-expansion is achieved (Figure 1). This is usually manifested by the operator noting resistance to aspiration, or the patient may begin to cough or experience an increase in local pain as the pleura comes in contact with the needle or catheter. At this point, the catheter or needle is removed and an occlusive dressing placed. Repeat chest radiography should be done immediately to confirm re-expansion.

Figure 1.

(A) The stopcock is opened to the syringe and air is aspirated. (B) The stopcock is closed and air is expelled.

The BTS considers simple aspiration to be first-line treatment for all PSP requiring intervention. This is defined as any PSP not meeting criteria for observation alone, due to either the size of pneumothorax or patient symptomatology (5). They also suggested in 2003 that it is reasonable to attempt a second simple aspiration maneuver if the first is unsuccessful; assuming that only a small amount of air was aspirated during the first attempt. However, the 2010 guidelines state that repeat aspiration is unlikely to be successful and should not be done unless there were technical difficulties in the first attempt. The 2001 ACCP guidelines do not endorse simple aspiration as a first-line treatment, only mentioning it as a possible intervention if pneumothorax progression occurs in the patient initially managed conservatively with observation.[6] This view may be evolving, however, as others, including some of the authors of the initial ACCP statement, have recently favored aspiration as an initial treatment for PSP.[15] In fact, although traditionally this treatment approach was reserved for PSP, the BTS 2010 update suggests that simple aspiration may be considered in asymptomatic patients with a small SSP, although there seems to be little evidence in support of this suggestion.[13]

In head-to-head studies, simple aspiration has compared favorably to tube thoracostomy in management of stable PSP.[15–18] A Cochrane review in 2007 showed no difference in immediate success or early failure rate between the two interventions, while demonstrating a decrease in hospitalization with simple aspiration.[17] The study also showed no difference in duration of hospitalization or 1-year success rates. A 2008 review of the Emergency Medicine literature corroborated these findings, showing no difference in the outcomes of immediate failure, 1-week failure, risk of complication, and 1-year recurrence rate.[18] Theoretical complications of needle aspiration include bleeding, infection, vasovagal reaction, and subcutaneous emphysema. However, in a review of the literature on over 300 cases of simple aspiration, there were only three documented cases of hemothorax and one of pneumonia.[15] It seems that risk of complication in simple aspiration is low.

There is a lack of strong evidence for appropriate discharge criteria and follow-up for patients after simple aspiration. The BTS only states that the patient should be observed to ensure clinical stability before discharge and gives no specific follow-up instructions other than to return immediately with development of breathlessness. As the ACCP does not recommend simple aspiration as a primary intervention, there are no follow-up recommendations. However, the ACCP does recommend follow-up within 48 h for repeat radiography with both observation and patients discharged after small-bore catheter insertion, so it is reasonable to apply this same recommendation to simple aspiration as well. There is also a lack of agreement on what is considered a "successful" simple aspiration. In a recent review of the literature on the role of simple aspiration in management of PSP, the author points out that a quantifiable definition has not been established beyond "the immediate complete or near-complete re-expansion of lung after aspiration".[15] The BTS recommends a limit of 2.5 L of air removed during simple aspiration, whereas other studies used a cutoff of 4 L.[5,15] Persistent pneumothorax above these cutoffs is considered indication for catheter placement, given the likelihood of a persistent air leak.

We recommend that simple aspiration be used in stable patients with PSP who do not meet criteria for observation alone, either due to pneumothorax size or shortness of breath at rest. Simple aspiration may also be considered in patients with small pneumothorax who have failed conservative management. No more than 4 L of air should be aspirated, and immediate repeat radiography should be done. Patients who have both radiographic resolution and improvement in symptoms may be discharged if able to follow-up within 48 h.

Small-bore Catheter Insertion, With Heimlich Valve. Another less invasive technique, in comparison to tube thoracostomy, is placement of a small-bore (7–14 F) catheter. This can be done by using either the Seldinger catheter-over-wire technique or a catheter-over-needle pneumothorax kit. Similar to simple aspiration, this technique is generally reserved for stable, closed pneumothoraces. This includes PSP, but also secondary spontaneous, iatrogenic, and recurrent pneumothorax after observation or chest tube removal. Whereas simple aspiration is contraindicated in patients with underlying lung disease, such as chronic obstructive pulmonary disease, small-bore catheter insertion may be an appropriate intervention in these patients. Although small-bore catheter is not indicated for initial treatment of a traumatic pneumothorax, it may be used for a recurrent pneumothorax after chest tube removal, including post-trauma. Tension pneumothorax or clinical instability is a contraindication to small-bore catheter insertion.

A retrospective, comparative study of large- (20–32 F) and small-caliber (6–12 F) catheters found similar success rates in relieving pneumothorax, whereas large-bore catheters had higher infection and overall complication rates, 24% and 32%, respectively.[19] There was a "displacement" rate of 21% of small-bore catheters in that same study. In another study, the most frequent complication of small-bore catheters was found to be tube dislodgement or misplacement, which occurred in 23% of cases.[20] Yet another study showed displacement rates of 21% and a blockage rate of 9%.[21] Although these studies showed a relatively frequent incidence of minor complications, there was a near absence of any major or life-threatening complications.[19,20,21,22] A recent study of complications of chest tube insertion performed by residents in the ED reported an increased rate of kinking and misplacement in tubes < 36 F.[23] However, these were minor complications that could easily be fixed if identified early. The overall rate of major complications was < 2% for all chest tubes placed by residents.[23] Insertion of a small-bore catheter is a procedure that can be easily performed by Emergency Physicians and can be quite effective without major complication.

Another advantage to the small-bore catheter is that it may also be attached to a Heimlich valve (Figure 2). This one-way flutter valve may make the patient with a stable pneumothorax a candidate for outpatient therapy, given that the patient has a good understanding of his diagnosis and treatment, as well as reliable follow-up.[20–26] Another device similar to the small-bore catheter with Heimlich valve is the thoracic vent, a polyurethane catheter connected to a plastic container with a one-way valve. Studies done in the 1990s showed no significant difference in rates of re-expansion or complications between the thoracic vent device and tube thoracostomy, with a decrease in hospitalizations and cost.[27,28] By treating pneumothoraces on an outpatient basis, hospital admissions and therefore costs are decreased, without a significant increase in complications or recurrence.[28,29] Both BTS and ACCP guidelines recommend small-bore catheter with Heimlich valve for a spontaneous or iatrogenic pneumothorax that does not meet criteria for simple aspiration (patients with underlying lung disease or with "large pneumothorax"), or in the event of simple aspiration failure.[5,6]

Figure 2.

(A) Heimlich valve. (B) Ambulatory Heimlich valve placement for outpatient management. (C) Heimlich valve for inpatient management.

We recommend small-bore catheter insertion for all patients with stable PSP who do not meet criteria for observation or simple aspiration as discussed above, as well as for all patients initially failing one of these two modalities. Additionally, this technique should be used as first-line treatment for all stable secondary spontaneous or iatrogenic pneumothoraces.

Seldinger Catheter-over-wire Technique. The Seldinger technique is performed in a manner similar to central venous access (Table 3). Either the midaxillary fourth or fifth intercostal space or the midclavicular second intercostal space is anesthetized locally. Using sterile technique, an 18-gauge needle with a 5-mL syringe is inserted over the rib and into the space, pulling back on the syringe during insertion until the pleural space is entered as evidenced by aspiration of air. The syringe is removed and a wire is inserted through the needle into the pleural space. The needle is removed, and using a #11 scalpel, a nick is made in the skin. A dilator is passed over the wire and removed, and a small-bore (8 F) catheter is passed over the wire into the pleural space. The wire is removed, and at this point the catheter can be hooked up to a pleural drainage system (Figure 3). Alternatively, once a small-bore catheter is positioned, a one-way flutter valve, also known as a Heimlich valve, can be placed on the external terminus of the catheter, allowing passage of air out of the lung. The major benefit of the Heimlich valve, as compared to a chest tube placed on water seal, is that the patient can potentially be treated as an outpatient.

Figure 3.

(A) 18-gauge needle with 5-mL syringe, guide wire, and 8 F catheter are used for the Seldinger technique. (B) The needle is inserted until air is aspirated. (C) The guide wire is passed through the needle. (D) The catheter is passed over the guide wire into the pleural space.

Catheter-Over-Needle Pneumothorax Kit

This technique is performed in a location and fashion similar to the Seldinger technique; however, there is no wire ( Table 4 ). Instead, once the 18-gauge needle is confirmed to be in the pleural space with aspiration of air, a nick is again made in the skin and an 8 F catheter, which is pre-loaded with the needle, is simply advanced over the needle into the pleural space. The needle is then removed and the catheter can be connected to a Heimlich valve or pleural drainage system (Figure 4).

Figure 4.

(A) 8 F catheter over 18-gauge needle. (B) The catheter-over-needle is advanced into the pleural space. (C) The needle is removed from the catheter.

Post-procedure Care

Discharge after placement of a small-bore catheter with a Heimlich valve is contingent upon a chest radiograph demonstrating re-expansion, the resolution of symptoms, and reliable follow-up. Different studies on the subject matter have advocated repeating radiography at 3–4 h or 4–6 h, with discharge and ambulatory treatment if re-expansion is achieved.[20,24,30] All studies recommend daily follow-up for repeat imaging, highlighting the importance of reliability as a necessity for discharge. There is differing opinion on the appropriate length of time to wait before removal of catheter. In one study, the valve was closed after 6 or 7 days of treatment and removed if there was no evidence of persistent pneumothorax or air leak.[24] Another recommends a minimum of 2 days of treatment, at which point the valve can be closed and repeat imaging done 4–6 h later, with removal of catheter if re-expansion is maintained..[30] This study suggests a longer treatment period for larger and recurrent pneumothoraces. Finally, in yet another study, patients received a repeat chest radiograph 1 h after catheter placement. If there was re-expansion, the valve was closed and this was repeated after another 4–6 h. If the lung remained expanded, the catheter was removed, the patient was discharged home, and a follow-up chest X-ray study was obtained 24 h later.[20] Failure of re-expansion using Heimlich valve generally requires catheter attachment to a pleural drainage system and hospital admission. Persistent and recurrent pneumothorax may necessitate large tube thoracostomy and potentially, surgical intervention.

For patients in whom re-expansion is achieved using small-bore catheter, we recommend discharge with Heimlich valve if the patient is able to have reliable follow-up at 24 and 48 h for repeat imaging. Alternatively, in ED settings in which time allows, an asymptomatic patient may be observed for a minimum of 4 h and then have a repeat chest X-ray study done. If no recurrence is seen, the catheter may be removed and the patient discharged with follow-up in 24 h.

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