Correspondence

Chest-Tube Insertion

N Engl J Med 2008; 358:749-750February 14, 2008

Article

To the Editor:

In the video on chest-tube insertion, Dev et al. (Oct. 11 issue)1 note that chest tubes are generally marked with numbers to indicate the distance into the chest wall. However, this is not the case with the chest tube shown in the video or with models I have used. The centimeter markings shown refer to the distance from the most proximal side hole. Thus, the 2-cm marking lies approximately 4.5 cm from the tip on a 12-French chest tube and 6 cm from the tip on a 20-French tube of the same brand. This subtle difference is particularly important in small neonates, in whom the optimal insertion length may be less than 5 cm. Such patients are thus at risk for chest-tube impingement on the mediastinum, with potential phrenic-nerve injury and diaphragmatic paralysis.2-5

A more intuitive marking system — for example, with the use of “0 cm” (at the proximal hole), “tip + 2 cm,” “+ 4 cm,” “+ 6 cm,” and so on — along with brief instructions on the package might help practitioners minimize the excessive depth of chest-tube insertion.

Joaquim M.B. Pinheiro, M.D., M.P.H.
Albany Medical Center, Albany, NY 12208
pinheij@mail.amc.edu

5 References

1. 1

   Dev SP, Nascimiento B Jr, Simone C, Chien V. Chest-tube insertion. N Engl J Med 2007;357:e15.
   

2. 2

   Arya H, Williams J, Ponsford SN, Bissenden JG. Neonatal diaphragmatic paralysis caused by chest drains. Arch Dis Child 1991;66:441-442
   CrossRef | Web of Science | Medline

3. 3

   Nahum E, Ben-Ari J, Schonfeld T, Horev G. Acute diaphragmatic paralysis caused by chest-tube trauma to phrenic nerve. Pediatr Radiol 2001;31:444-446
   CrossRef | Web of Science | Medline

4. 4

   Odita JC, Khan AS, Dincsoy M, Kayyali M, Masoud A, Ammari A. Neonatal phrenic nerve paralysis resulting from intercostal drainage of pneumothorax. Pediatr Radiol 1992;22:379-381
   CrossRef | Web of Science | Medline

5. 5

   Philipps AF, Rowe JC, Raye JR. Acute diaphragmatic paralysis after chest tube placement in a neonate. AJR Am J Roentgenol 1981;136:824-825
   Web of Science | Medline

To the Editor:

I think that the article by Dev et al. should have clarified that although there may be variations in physicians' practices with regard to the technique of removing a chest tube,1 only one technique is consistent with the physiology of the pleural space. The pleural space is most often at a negative pressure in relation to the atmospheric pressure, which creates a gradient that favors passage of air from the atmosphere to the pleural space. Pneumothorax will occur if air flows from the atmosphere following this gradient. To prevent a pneumothorax, this gradient should be eliminated by making the pleural pressure higher than the atmospheric pressure. During spontaneous ventilation, expiration is the only portion of the respiratory cycle when the pressure in the pleural space is higher than the atmospheric pressure. In this setting, chest tubes should be removed as the patient exhales, not at end-inspiration or end-expiration. In patients receiving mechanical ventilation, the pleural pressure may be higher than the atmospheric pressure during late inspiration. In this setting, chest tubes should be removed as the ventilator completes its inspiration cycle.

Luis D. Berrizbeitia, M.D.
University Medical Center at Princeton, Princeton, NJ 08540
ldberriz@ctsx.net

1 References

1. 1

   Baumann MH. What size chest tube? What drainage system is ideal? And other chest tube management questions. Curr Opin Pulm Med 2003;9:276-281
   CrossRef | Web of Science | Medline

Author/Editor Response

We concur with Pinheiro that the numerical markings on the side of most currently used chest tubes correspond to the distance from the proximal drainage hole and that the insertion distance into the chest wall would be more accurately measured if the numerical markings explicitly noted the proximal hole as a “zero” reference point. In contrast to the data on chest-tube insertion in neonates, which was not the subject of our video, empirical information about safe distances for advancing chest tubes into the pleural space in adults is lacking.

Berrizbeitia explains the physiology of pleural pressure variations in spontaneously breathing patients. However, in actual clinical practice, the current level of evidence does not point to a clearly superior timing strategy for chest-tube removal, suggesting that other factors, besides the timing of removal, may better predict the development of pneumothorax. Indeed, one small, randomized trial involving spontaneously breathing patients showed that the risk of pneumothorax was no different with chest-tube removal during end-inspiration than with removal during end-expiration.1 However, we disagree with Berrizbeitia's explanation with respect to mechanically ventilated patients, who almost always receive positive end-expiratory pressure and thus have positive pleural pressure throughout much of the respiratory cycle. We could not find a randomized trial comparing the timing of chest-tube removal in mechanically ventilated patients.

Shelly P. Dev, M.D.
Carmine Simone, M.D.
Sunnybrook Health Sciences Centre, Toronto, ON M4N 3M5, Canada
shelly.dev@sunnybrook.ca

1 References

1. 1

   Bell RL, Ovadia P, Abdullah F, Spector S, Rabinovici R. Chest tube removal: end-inspiration or end-expiration? J Trauma 2001;50:674-677
   CrossRef | Web of Science | Medline