Orders for Chest Drainage

Q. Hi, I am a practicing clinical RN at a adult transplant ICU in a large teaching hospital. The residents in our hospital always argue with me on how to write chest tube orders. So there is water seal, which does not require any suction, except gravity. Sometime they would write -20 cm water seal suction. Is this a valid order to write? My understanding is that you either put it to water seal, or -20 cm water suction, which is control by the chamber to the most left in Atrium Ocean model. Please help me. Thank you very much.

A. Unfortunately, I was unable to find any standards for how orders are written for chest drainage. However, there are some interesting studies about communicating accurately and potential errors that can result from communication errors, which is what you describe.

All patients with chest tubes have a water seal (or a mechanical equivalent in dry seal drains) which is the one-way valve that allows air to leave the chest and prevents it from re-entering. Applying suction to the chest tube is an option; as you describe, some patients have suction applied and others do not. It seems that the physician literature uses the term “water seal” to describe a situation in which suction is not being used. I have used and prefer to describe a drain with no suction as being “gravity drainage,” since it describes how drainage is leaving the chest. If you have suction, the negative pressure pulls air and fluid out of the chest; without suction, it is the pressure differential caused by the position of the drain below the chest – gravity — that allows air and fluid to drain.

Using this terminology, orders would read:

  • Chest drain to -XX cmH2O suction drainage
  • Chest drain to gravity drainage

But, as the literature shows, being “correct” may not be as safe as being consistent in terminology. I’m sure you have been through inservices on handoffs, but clear orders are equally important.1-3 Root causes of sentinel events have consistently been communication problems more than 60% of the time since 1995.2 One study of malpractice claims showed communication errors were postoperative 32% of the time, between one transmitter and one receiver 64%, information communicated was inaccurately received 44%, and between persons from two different disciplines 34% of the time1 – each of these factors apply to your concern.

How can this problem be addressed? First, a common terminology needs to be agreed to by a multidisciplinary team of nurses and surgeons. (I’m sure with a little investigation, you’ll see chest drainage is not the only terminology issue.) Standardized postoperative orders and clinical pathways incorporating the agreed upon terminology will not only reinforce the terms but set standards so deviations can be clarified (suction not ordered when expected and vice versa).3 Finally, house staff need to be oriented to hospital policy and protocol; one survival skills curriculum presented through the month of July focuses on communication skills, writing orders and progress notes, and problem solving by simulating “midnight” calls from nurses about a variety of patient scenarios.4 This would be an ideal opportunity to clarify just the issue you raise.

1. Greenberg CC, SE Regenbogen, DM Studdert, et al.: Patterns of communication breakdowns resulting in injury to surgical patients. J Am Coll Surg Apr 2007;204(4):533-540. 17382211

2. O’Byrne WT, 3rd, L Weavind, J Selby: The science and economics of improving clinical communication. Anesthesiol Clin Dec 2008;26(4):729-744, vii. 19041626.

3. Stahlfeld KR, JM Robinson, EC Burton: What do physician extenders in a general surgery residency really do? J Surg Educ Sep-Oct 2008;65(5):354-358. 18809165.

4. Todd SR, BN Fahy, J Paukert, ML Johnson, BL Bass: Surgical intern survival skills curriculum as an intern: does it help? Am J Surg Dec 2011;202(6):713-718; discussion 718-719. 22019283.


Subcutaneous Air

Subcutaneous air courtesy trauma.org

Q. What causes subcutaneous emphysema in a patient with a pleural chest tube with a persistent air leak? Is it treatable and what assessments should be considered in patient care?

A. Subcutaneous air, also called subcutaneous emphysema or surgical emphysema, occurs in patients with chest tubes when air leaks under enough pressure to track along the tissue planes in the deepest layer of the skin, the subcutaneous layer. This can occur at the drain site or at a different site of pleural injury.1

Air or fluid will take the path of least resistance. For patients with pneumothorax or a postoperative air leak, that is usually through the chest tube. However, there are situations in which the path through the tissue is accessible and less resistant to air flow than the route through the chest tube:


  • Chest tube is too small (the smaller the tube’s diameter, the higher the resistance), particularly in relation to the size of the pleural incision
  • Chest tube is occluded2
  • Chest tube eyelet(s) has migrated out of the pleural space2
  • Dependent loop in drainage tubing is filled with stagnant fluid3
  • High ventilator pressures, particularly PEEP4
  • Chest tube penetrating lung parenchyma or other errors in placement1,2,4

Two retrospective reviews have examined the association of subcutaneous air with chest drainage. In one, 18% of chest tube patients had subcutaneous air (SQ).2 Of these, 80% were patients with pneumothorax or postthoracotomy; 20% had pleural effusions. Compared with a paired cohort at 3%, 20% of SQ patients had errors in tube placement. The other study looked at a database of patients with pulmonary resection in which 6% had clinically apparent SQ.5 Patients with poor preoperative pulmonary function, air leaks, and previous thoracotomy were more likely to have SQ. The researchers discovered that patients whose SQ did not resolve with chest drain suction had postop lung adherence to the intercostal space that had been opened, causing an alveolar-subcutaneous fistula. After a 16-minute (median time) VATS procedure to resolve the adhesion, the air was redirected to the pleural space, and 98% of patients’ SQ was resolved within 24 hours.5

Case studies have been published describing clinical conditions associated with subcutaneous emphysema, including bronchial disruption from blunt chest trauma following extrication after an earthquake,6a motor vehicle crash,7 and a bicycle accident.8 It can also be the first sign of an iatrogenic pneumothorax following subclavian venous catheter4 or pacemaker1insertion.

There have also been reports of air entering the epidural space9 and vertebral artery dissection10 after subcutaneous air from pneumothorax tracked into the neck. The posterior mediastinum and neck can communicate through fascial planes, and from there, air can move into the spinal canal through the intervertebral foramen, the opening for the spinal nerve.9

While most instances of subcutaneous air relating to chest drainage are troubling cosmetically, it usually resolves without further problem.1,3 However, in rare cases, air in the neck can lead to airway obstruction, first evidenced by a change in voice.1,5 In addition, air in the tissue planes of the chest can cause a restrictive limit on respirations,1,8 similar to that seen with edema following chest wall thermal burns. The most important care is to determine why the subcutaneous leak is occurring and to correct that problem.2If the tube isn’t functioning properly, the patient could be at risk for recurrent pneumothorax and even tension pneumothorax, particularly with positive pressure ventilation.1

Nursing assessment of any patient with a chest tube should include regularly palpating the chest wall surrounding the tube. There is no routine need to remove the dressing; this palpation can be done over and around the dressing. If air accumulation is sudden and extensive, it will be easily visible. As with any evidence of a significant change, check airway, breathing and circulation first and then proceed to the drain.

Once subcutaneous air is detected, a thorough, but rapid assessment is important to determine if there is a problem with the chest drain system that can be easily fixed. Trace the tube from where it leaves the chest to the drain to ensure it is not pinched, kinked, or clamped; ensure there is no fluid in the tubing that could collect in a dependent loop.3 If suction is ordered, check the suction control chamber to make sure there is bubbling or that the suction indicator is visible in a dry control drain. If no suction is ordered, check to make sure the drain is open to atmosphere; if there is a stopcock on the suction tubing, make sure it is fully open.

If the drain is not connected to suction, the next step is usually to get an order to connect to suction and for a chest x-ray to check for pneumothorax, chest tube position, and lack of lung re-expansion.3,5,7,9 Sometimes, restarting or increasing the level of suction may solve the problem. If the patient is not on a ventilator and there are no contraindications, administering oxygen with a non-rebreather mask will facilitate resorption of nitrogen from the tissues.1

If no cause is evident, carefully remove the dressing to inspect the chest tube as it leaves the chest wall. Chest tubes have openings in the distal end to facilitate drainage. The number and position of the holes depends on the particular tube. In addition, tubes have a blue line that will show on an x-ray. The opening closest to the skin will be on the line enabling the position to be checked on a chest x-ray as a gap in the line (see arrow).2 Even if the opening isn’t visible at the incision, it may be outside the pleural space, allowing air to flow into the subcutaneous tissue. If the tube has pulled out slightly, it will have to be replaced. The tube is no longer sterile once it crosses the incision, so it cannot be pushed back into the chest.

Chest tubes

Keep in mind that even if tube malposition didn’t cause the subcutaneous air, as air accumulates, the skin becomes “thicker” and this can cause the tube to slide out of proper position.2 If the tube doesn’t seem to be working, the physician may choose to add another tube or replace the potentially malfunctioning tube.4,9

Once the chest tube situation has been addressed, and the patient is no longer at risk, additional nursing care will need to focus on skin care. In a large majority of cases, air will be reabsorbed without sequelae. There have been some reports of incising the fascia to allow air to escape, inserting angiocatheters connected to suction into the subcutaneous space, and tissue massage, and a detailed report describes the use of a negative pressure wound therapy dressing, complete with information on integrating this dressing with chest drainage.11 The time for resolution will depend on the cause, the control of the cause, and the area affected. In the meantime, meticulous care of the distended skin and protection from friction and shear forces will reduce the risk for skin breakdown.

1. Williams DJ, SI Jaggar, CJ Morgan: Upper airway obstruction as a result of massive subcutaneous emphysema following accidental removal of an intercostal drain. Br J Anaesth Mar 2005;94(3):390-392. 15579486.
2. Jones PM, RD Hewer, HD Wolfenden, PS Thomas: Subcutaneous emphysema associated with chest tube drainage. Respirology 2001;6:87-89.
3. Cassivi SD. Chest tube insertion and management. In: Albert RK, SG Spiro, JR Jett, eds. Clinical Respiratory Medicine. 3 ed. Philadelphia: Mosby, Inc.; 2008.
4. Shaikhrezai K, V Zamvar: Hazards of tube thoracostomy in patients on a ventilator. J Cardiothorac Surg 2011;6:39. 21447174.
5. Cerfolio RJ, AS Bryant, LM Maniscalco: Management of subcutaneous emphysema after pulmonary resection. Ann Thorac Surg May 2008;85(5):1759-1763; discussion 1764-1755. 18442580.
6. Ozcelik C, S Onat, ES Bayar: Combined late diagnosed right main bronchial disruption and chylothorax from blunt chest trauma. Annals of Thoracic Surgery 2004;78:e61-62.
7. Leonard M: A 21-year-old man with pneumothorax, subcutaneous emphysema, and a persistent air leak after chest tube insertion. Journal of Emergency Nursing 2003;29(5):425-426.
8. Criddle LM: An unusual case of tension pneumothorax. American Journal Of Critical Care 1995;4(4):314-318.
9. Park JS, H Kim, SW Lee, JH Min, SW Kim, KW Lee: Symptomatic pneumorrhachis after chest tube insertion for spontaneous pneumothorax. Am J Emerg Med Sep 2010;28(7):846 e841-842. 20837275.
10. Rabkin DG, P Benharash, RJ Shemin: Vertebral artery dissection after iatrogenic cervical subcutaneous emphysema. Journal of Cardiac Surgery 2011;26:54-56.
11. Sciortino CM, GS Mundinger, DP Kuwayama, SC Yang, MS Sussman: Case report: Treatment of severe subcutaneous emphysema with a negative pressure wound therapy dressing. ePlasty 2009;9:e1.

Suction: Wet or Dry?

Q. Is there any research to show that the water (wet) suction is more reliable than your dry suction? What are the advantages/disadvantages of each?

A. I’m happy to discuss wet and dry suction in general. For individual product specifications, I’ll have to refer you to the manufacturer of the chest drain(s) you use. I am not aware of any published research comparing the two approaches. Both will protect the patient and provide a window to the pleural space through the water seal chamber for asses

Chest drain with wet suction control



A water column is the original method used to control the amount of negative pressure that can be transmitted to the chest. When disposable integrated drains were developed, this was transformed into a suction control chamber. The level of the

water in this chamber determines the limit of the negative pressure that can be transmitted to the chest. Challenges with water-based systems are the noise of the bubbling, and the potential for water evaporation. As water evaporates and the water level drops, the amount of negative pressure transmitted to the chest will also decrease. In addition, water-filled units take longer to set up, they weigh more when operating (a potential issue for transport), and if the drain is knocked over, the water can spill over into other chambers.

There are basically two types of dry suction. A small minority of drains operate with a restrictive orifice mechanism. In these drains, you would adjust a small knob that makes the path by which air leaves the drain larger or smaller in diameter, which indirectly limits the negative pressure. The problem with this is that it severely limits air flow out of the drain. A patient with a pneumothorax may have retained air as a result, particularly if on a ventilator. In addition, there is no self-adjustment if there is a change in the amount of flow from the vacuum source or from the patient.

The other, much more common, type is a self-regulating dry suction in which a small regulator is built into the drain. As long as there is adequate flow from the wall (which will be indicated on the drain) it will accurately adjust to changes in the source vacuum or the patient to maintain suction at the level set on the drain. It’s also silent. No bubbling is needed. In addition, these drains provide a wider range of suction levels, from -10cmH2O to -40cmH2O; there’s no evaporation to worry about; if the drain is knocked over, there is much less water to move between chambers; it’s lighter during operation; and it’s quicker to set-up. However, all these conveniences come with a higher price per drain.


Patient Transports

Q. Hi, I am wondering what the best practice is for air transporting a patient with a pneumothorax treated with a chest tube. Is a commercial 3 bottle

Medevac helicopter

system sufficient or should you also place a Heimlich valve with the 3 bottle system or simply a Heimlich valve for air transport. Thanks, Derek

A. Heimlich valves were designed by Dr. Harry Heimlich to facilitate air transport of wounded service members in Vietnam.1 The problem with Heimlich valves is the lack of a way to collect fluid drainage. Allowing fluid to flow onto the floor of the aircraft as it was done originally in combat violates standard precautions, and jury-rigging some sort of collection bag presents the risk of outflow obstruction with subsequent tension pneumothorax. These challenges led to the development of the Pneumostat chest drain valve about 10 years ago. This closed unit includes a self-contained 30 mL collection chamber to catch any fluid that may drain from the pleural space in a patient with pneumothorax. The two valves are comparable in size as illustrated here.

Patients with potential for greater volumes of fluid drainage, or longer transport times can use the Express Mini 500 drain. It is a full-featured chest drain about 9 inches high and 5 inches wide with a collection chamber capacity of 500cc, a mechanical one-way valve, option for suction (-20cmH2O if connected to a vacuum source), and safety features present in larger, more traditional drains. It is made of plastic, without risk of breakage you may see with bottles.

Historically, the U.S. Military required placing a Heimlich valve as close to the patient as possible and then connecting the tube to a chest drain. That’s because flight condition simulation testing demonstrated that during rapid decompression and

Air Force Medical Evacuation

descent, water could be sucked out of the water seal chamber, leaving the patient unprotected. This instruction was revised in 2008 after testing of the Atrium model 4050 drain. Since this drain has a dry, mechanical one-way valve rather than a water- dependent one-way valve, there is no danger of losing the patient protection with changes in cabin pressure. While the Express Mini and the 4050 use water to demonstrate air leak, the water does not create the one-way valve; thus, no Heimlich is needed. In fact, the instructions warn against using a Heimlich with this type of drain. In addition, these drains with mechanical suction regulators and one-way valves are less position-sensitive than the water-based drains.

The decision to use a Heimlich with a drain should be based on the type of drain used and the pressure swings patients would be exposed to during transport. The Air Force tested for 8000 to 45000 feet altitude. If your patients will not be exposed to these conditions, I would not recommend combining a Heimlich with a traditional drain. Having two one-way valves could increase resistance to air leaving the chest.

In preparing patients for air transport, it is essential to carefully review a chest radiograph for the presence of extrapulmonary air. Unfortunately, there is no research that predicts the amount of extrapulmonary air that may be acceptable for flight.2 Other diagnostic imaging such as ultrasound and CT scan may be used to confirm the diagnosis. It is also important to consider the mechanism of injury and the risk for pneumothorax during the transport period. For example, a patient with flail chest (multiple ribs fractured in multiple places) is at high risk for lung injury, even if a pneumothorax is not evident on initial evaluation. Consider the altitude of the planned air transport, the length of the anticipated trip, and whether the patient will require positive pressure ventilation, which increases risk for tension pneumothorax.3

If there is any question about the presence or size of a pneumothorax, it should be treated before flight. Patients with untreated pneumothorax are at risk for significant expansion of the trapped air at altitude which can change a small, clinically insignificant pneumothorax into a life-threatening tension pneumothorax. Increasing intrapleural pressure can cause desaturation and hemodynamic compromise.2,4 In-flight chest decompression is fraught with hazard and should be avoided if at all possible.

1. Heimlich HJ. Heimlich valve for chest drainage. Medical instrumentation. Jan-Feb 1983;17(1):29-31.

2. Currie GP, Kennedy A, Paterson E, Watt SJ: A chronic pneumothorax and fitness to fly. Thorax 2007;62:187-189.

3. Kaczala GW, Skippen PW: Air medical evacuation in patients with airleak syndromes. Air Medical Journal 200827(2):91-98.

4. Essebag V, Halabi AR, Churchill-Smith M, Lutchmedial S: Air medical transport of cardiac patients. Chest 2003;124(5):1937-1945.

Assessing Bubbling in the Water Seal

Q. I have been asked to do a chest tube competency for our surgical unit staff and have not had any experience myself. After viewing the video about managing chest drainage and asking others here questions I am still a little confused about the water seal chamber. Bubbling in the chamber can be both good and bad, one indicates an air leak, the other indicates a normal condition. I’m just not sure how to distinguish between good and bad exactly. Also someone here told me that when the water level rises in the water seal chamber that also can be good and bad. Again could you explain this? I am also confused about tidaling as it says you should see this but it can be normal not to occur. Everything about this chamber seems to be a contradiction. How do I know what is good vs bad?

Robert Cole, RN
Nursing Education Department
St Joseph Health Services of RI

A. Rather than thinking about good vs. bad, it might be easier to think about whether bubbling is expected or unexpected. Bubbling occurs in the water seal chamber when air is entering the chest drain. When you first apply suction, there should be a little bubbling in the water seal as air is pulled through from the collection chamber. If no other air enters the system, the bubbling should soon stop. Bubbling continues when air is entering the system.

  • What is going on with your patient? If the tube has not been in for long and the patient had a pneumothorax or lung resection surgery, you should expect bubbling.
  • What have previous nursing assessments shown? If the patient is 18 hours post-op and has had bubbling in the water seal since leaving the OR, I wouldn’t be worried at all. However, if the patient is 36 hours post op and I am seeing bubbling after 24 hours of no bubbling, I’d want to investigate further.

If an air leak is not expected from your patient assessment, there may be a leak in the system – somewhere between the chest tube and the drain itself. An air leak can be “normal” when it is expected and makes sense with the rest of the patient assessment. On the other hand, if you expect bubbling and don’t see it and the patient is short of breath with significantly diminished breath sounds on the side with the chest tube, the tube could be blocked and again, require additional assessment.

Here’s an analogy: let’s say a 32 year old man comes in to the ER with a broken wrist after slipping on an icy sidewalk. You put him on a monitor for sedation for a closed reduction, and you notice he’s in bigeminy. That becomes an incidental finding that doesn’t need treatment. If, however, you see the same rhythm in a patient having an MI with unstable blood pressure, it would need more investigation and probably speedy treatment.

As for the fluid in the water seal chamber, the water seal is a manometer that can measure intrapleural pressures. Pressure changes in the pleural space that occur with breathing will be seen as fluctuations in the level of the water within the tube. These fluctuations, called “tidalling,” may be as great as 5 to 10 cmH2O with normal spontaneous breathing. The water level will go up (more negative) during inspiration, and go down (return to baseline) during exhalation. If the patient is receiving positive pressure ventilation, the water level will go down (more positive) during inspiration, and go back up (return to baseline) during exhalation, reflecting the higher positive pressure in the chest with mechanical ventilation. If there is no tidalling, it could mean that:

  •  The tubing is kinked
  • The tubing is clamped
  • The patient is lying on the tubing
  • There is a dependent, fluid-filled loop in the tubing
  • Lung tissue or adhesions are blocking the catheter eyelets
  • No air is leaking into the pleural space and the lung has re-expanded

Once again, your complete patient assessment and knowledge of what’s been going on over the past 24 to 48 hours will help you interpret these findings.

Clamping Chest Tube Before Removal

Q. Is it necessary to clamp a chest tube prior to d/c the chest tube? What is best practice to go from suction to water seal, then clamp and d/c or suction to water seal and then d/c? Can you give me any contact information on references for best practice on clamping chest tubes prior to discontinuation? Thank you.

 Theresa Austin, MSN-L ,RN
RN Clinical Education Specialist- Pediatric Service line
Cardon Children’s Medical Center at Banner Desert Medical Center

A. To clamp or not to clamp? That is the question. I was not able to find any research that compared clamping with no clamping. For this response, I am thinking about patients with pleural tubes who are not receiving mechanical ventilation; I’d never clamp a tube if a patient were receiving positive pressure. As for other non-critical patients (typically postoperative) If I were writing the orders, I would prefer to have pleural tubes clamped the night before anticipated removal, and if the patient did fine, pull the tube on morning rounds. The argument in favor of clamping is that if the patient gets breathless or shows other signs of recurring pneumothorax, it is much easier to simply open the clamp rather than face the risk of pulling the tube too soon and having to replace it. I think clamping to simulate removal in order to assess the patient is hard to argue with, but is not evidence-based. Otherwise, I would not clamp a tube — even to change out a chest drain. I’d be concerned that I might get called from the bedside for an emergency and not open the clamp; it’s the same reason I don’t turn off monitor alarms – I just silence them.

As for the literature, a frequently referenced approach, called “provocative clamping,” is described in a letter to the editor of Annals of Thoracic Surgery as one way to manage patients with prolonged air leak.1 It’s provocative because it involves clamping a tube in a patient with a known leak from the surface of the lung. But one of the best resources is a letter to the editor of Chest in which a writer is in favor of clamping and provides 8 references to support his position. In response, the author of the original article responds with 5 references that support not clamping the tube2. (available online here with links to available full text references)

There has been some good evidence on suction versus gravity drainage after lung surgery. University of Pennsylvania researchers reported their experience randomizing postoperative pulmonary resection patients (not including LVRS) into two groups. One group’s chest drains remained connected to the vacuum regulator with the suction control chamber set for a level of –20 cmH2O; the others were disconnected from the wall vacuum and remained on gravity drainage with the water seal of the chest drain.3 Sixty-eight patients who underwent pulmonary wedge resection were included with 34 in each arm of the study. The two groups were evenly matched; 15 patients in each group had an air leak at the end of the operation. All patients were connected to wall vacuum in the operating room to re-expand the lung at the end of the case. Vacuum was disconnected for transport to the PACU. There, patients were randomized to resume vacuum or to stay on gravity water seal drainage – two days earlier than in a previous study4. If a pneumothorax >25% was present on a chest radiograph in the gravity drainage group, the chest drain was reconnected to wall vacuum with a suction level of –10 cmH2O until the pneumothorax was <10%. (Note that none of the patients was symptomatic.) Then, gravity drainage was reestablished. Patients on the wall vacuum protocol had suction control chambers set to –20 cmH2O.

Patients with air leaks in the gravity water seal drainage group had a mean leak duration of 1.50 days. In the wall vacuum group, mean leak duration was 3.27 days. Chest tubes in the gravity water seal patients remained in place a mean of 3.33 days; in the wall vacuum group, the mean duration was 5.47 days. Even when taking the length of staple lines into account, the differences between the two groups remained. The researchers found that the duration of air leaks in the gravity water seal group was about one-half the time of the wall vacuum group. Since many argue that suction is critical to apposition of the pleurae postoperatively, these researchers initially used suction on all patients in the operating room. These researchers note that visually, the bubbling is more vigorous in the water seal chamber when the chest drain is connected to wall vacuum, indicating a greater flow of air out of the lung. They suggest that the benefit of reducing airflow, thereby allowing the suture line to be more closely approximated, aids healing and outweighs any benefit of pleural apposition.

The researchers conclude that placing patients on gravity water seal drainage helps resolve air leaks after pulmonary surgery more quickly than when suction is used. They state that routinely using wall vacuum postoperatively is counterproductive.

Overall, the literature supports using gravity drainage and significantly limiting or avoiding use of suction altogether unless there is a specific indication for suction based on a careful patient assessment5-12. Based on these findings, I would go to water seal as soon as possible and remove the tube from there. There is no need to clamp the tube unless you wish to simulate chest tube removal to determine patient tolerance.

1. Kirschner PA: “Provocative clamping” and removal of chest tubes despite persistent air leak. Annals of Thoracic Surgery 1992;53(4):740-741.

2. Gupta N: Pneumothorax : Is Chest Tube Clamp Necessary Before Removal? Chest 2001;119(4):1292-1293.

3. Marshall MB, Deeb ME, Bleier JI, et al: Suction vs water seal after pulmonary resection: a randomized prospective study. Chest 2002;121(3):831-835.

4. Cerfolio RJ, Bass C, Katholi CR: Prospective randomized trial compares suction versus water seal for air leaks. Annals of Thoracic Surgery 2001;71(5):1613-1617.

5. Merritt RE, Singhal S, Shrager JB. Evidence-based suggestions for management of air leaks. Thorac Surg Clin. Aug 2010;20(3):435-448.

6. Cerfolio RJ, Bryant AS: The management of chest tubes after pulmonary resection. Thoracic Surgery Clinics 2010;20(3):399-405.

7. Cerfolio RJ, Bryant AS, Singh S, Bass CS, Bartolucci AA: The management of chest tubes in patients with a pneumothorax and an air leak after pulmonary resection. Chest 2005;128(2):816-820.

8. Powner DJ, Cline CD, Rodman GH: Effect of chest-tube suction on gas flow through a bronchopleural fistula. Critical Care Medicine 1985;13(2):99-101.

9. Alphonso N, Tan C, Utley M, et al: A prospective randomized controlled trial of suction versus non-suction to the under-water seal drains following lung resection. European Journal of Cardiothorac Surgery 2005;27(3):391-394.

10. Prokakis C, Koletsis EN, Apostolakis E, et al: Routine suction of intercostal drains is not necessary after lobectomy: a prospective randomized trial. World Journal of Surgery 2008;32(11):2336-2342.

11. Deng B, Tan Q, Zhao Y, Wang R, Jiang Y: Suction or non-suction to the underwater seal drains following pulmonary operation: meta-analysis of randomised controlled trials. European Journal of Cardio-Thoracic Surgery 2010;38:210-215.

12. Ayed AK: Suction versus water seal after thoracoscopy for primary spontaneous pneumothorax: prospective randomized study. Annals of Thoracic Surgery 2003;75(5):1593-1596.

Effects of PEEP and CPAP in the Pleural Space

Q. Is there any information about how much PEEP or CPAP is transmitted to the pleural space?

A. The amount of PEEP transmitted to the pleural space is determined by the compliance of the chest wall and the lung. If lung compliance is low (the lung is stiff), but the chest wall compliance is high, meaning it expands freely, very little PEEP is transmitted to the pleural space, resulting in high transpulmonary pressure (the difference between intrapulmonary pressure and pleural pressure).1 If lung compliance is high and the chest wall compliance is low (chest wall expansion is limited due to external factors, such as obesity or skeletal conditions), much more PEEP is transmitted to the pleural space. In this case, pleural pressure can be significantly higher than atmospheric pressure..1-3

1. Nunn JF: Positive end-expiratory pressure. International Anesthesiology Clinics 1984;22(4):149-164.

2. Mason RJ, Broaddus VC, Martin TR, et al., eds: Murray and Nadel’s textbook of respiratory medicine. 5th ed. Philadelphia: Saunders Elsevier; 2010; No. 1

3. Jardin F, Genevray B, Brun-Ney D, Bourdarias J: Influence of lung and chest wall compliances on transmission of airway pressure to the pleural space in critically ill patients. Chest 1985;88(5):653-658.


Bubbling and Pneumothorax

Q. Can you please advise whether continuous bubbling should be present in the air leak chamber whilst on continuous wall suction in a patient with a spontaneous pneumothorax who is breathing spontaneously with a dry suction drain? By the way – if the patient was ventilated, what would the difference be?

Wendy Gleeson
Clinical Nurse Specialist Emergency/Clinical Nurse Educator After Hours
Grafton Base Hospital
New South Wales, Australia

A. You’ll see bubbling in the water seal chamber when air enters the system. That is most commonly from the lung, but can also be from a leak somewhere else in the system; for example, if the tube has moved and one of the eyelets of the chest tube is outside the chest.

Negative pressure from suction pulls air from a leak through the drain and positive pressure from the chest — a strong cough, positive pressure ventilation, or a manual resuscitation bag – will push air into the drain. So, if a patient has a pneumothorax or a postoperative leak from the lung, suction will cause continuous bubbling and may make a leak look worse than it is. You’ll see the same pattern caused by PEEP on a ventilator because it is continuous positive pressure pushing air out of the leak. To accurately assess the patient breathing spontaneously with suction, momentarily disconnect the suction tube from the drain, check for bubbling, and then reconnect the tubing. You may be able to pinch the suction tubing closed to accomplish the same thing. I recommend avoiding wall vacuum adjustments for assessment purposes because it is too easy to forget to put it back on.

Otherwise, you would see intermittent bubbling that corresponds to respirations. With a ventilator, you’ll see bubbling on inspiration; if the person is breathing spontaneously, you should see bubbling on exhalation, or with a cough.

A spontaneously breathing person with a spontaneous pneumothorax probably does not need suction. The British Thoracic Society Pleural Disease Guideline 2010 states “suction should not be routinely employed” for managing spontaneous pneumothorax.1 You may also find the Clinical Update for June 2010 useful. While it discusses suction for postoperative patients, the concepts apply to spontaneous pneumothorax as well.

1. British Thoracic Society Pleural Disease Guideline Group. BTS pleural disease guideline 2010. Thorax. 2010;65(suppl 2).