Correspondence

“Keeling” Syndrome — A Late Complication of Pneumonectomy

N Engl J Med 1996; 335:1074October 3, 1996

Article

To the Editor:

Late complications after pneumonectomy include excessive mediastinal displacement to the ipsilateral side with bronchovascular compromise, bronchopleural fistula with empyema, and decreased pulmonary reserve in the event of a respiratory infection.1,2 We recently learned of an unusual late complication of pneumonectomy that was reported to us by the patient, who then treated himself successfully.

A 58-year-old man underwent a right pneumonectomy in 1994 for squamous-cell carcinoma of the lung. His perioperative course was uncomplicated, and he soon resumed work. Fifteen months later, he asked about resuming his favorite sport, scuba diving, saying that his exercise endurance was good. His chest radiograph (Figure 1Figure 1Chest Radiograph of the Patient 15 Months after Right Pneumonectomy, Showing the Expected Opacified Right Hemithorax, with Rightward Shift of the Mediastinum, and a Normal Left Lung.) showed the usual post-pneumonectomy changes of an opaque (fibrous-tissue–filled) right pleural cavity; the left lung was normal. His pulmonary function was good for a person with one lung (forced expiratory volume in one second, 2.08 liters, or 54 percent of the predicted value). His request was therefore granted.

The patient returned several months later and reported that he did well diving, except for the problem of “keeling.” He explained that when submerged, he had difficulty remaining level while swimming. He would keel over, with the left side of his body turning upward toward the surface. As an experienced diver, he realized that he had a unilateral loss of an air-containing body structure (his right lung). He subsequently attached additional weight to his left side. This counteracted the asymmetric buoyancy of his body, and he can now dive and swim level.

The buoyancy of an object in water is determined by comparing the weight of the water it displaces with the weight of the object. If the water displaced weighs more, the object has positive buoyancy and will float upward. The human body has natural positive buoyancy that is caused primarily by the air-containing lungs and secondarily by body fat, which is less dense than water. The scuba tank (after some of the compressed air is expended) and wet suit (when used) may add to this positive buoyancy. Therefore, almost all divers must wear additional weight in the form of a lead-weight belt to become submerged and achieve neutral buoyancy.3 Unlike most normal people, however, in whom the positive buoyancy is symmetric, this patient had asymmetric buoyancy that he overcame by wearing an asymmetric set of weights.

Lary A. Robinson, M.D.
Mark W. Rolfe, M.D.
H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612-9497

3 References

1. 1

   Grillo HC, Shepard JA, Mathisen DJ, Kanarek DJ. Postpneumonectomy syndrome: diagnosis, management, and results. Ann Thorac Surg 1992;54:638-651
   CrossRef | Web of Science | Medline

2. 2

   Patel RL, Townsend ER, Fountain SW. Elective pneumonectomy: factors associated with morbidity and operative mortality. Ann Thorac Surg 1992;54:84-88
   CrossRef | Web of Science | Medline

3. 3

   Gravel DK. Scuba diving. Champaign, Ill.: Human Kinetics, 1993:43-4, 62-4.
   

Citing Articles (1)

Citing Articles

1. 1

   Kay Tetzlaff, Einar Thorsen. (2005) Breathing at Depth: Physiologic and Clinical Aspects of Diving while Breathing Compressed Gas. Clinics in Chest Medicine 26:3, 355-380
   CrossRef