intubation: knotting of the tube within the stomach with resultant traumatic withdrawal through the nose. While patient's an intern, I discovered a Miller-Abbott tube could through the of a because junction esophagogastric large and complex knot. After pronot be withdrawn even longed and painful manipulation under fluoroscopy, surgical consultation seemed necessary when a radiology consultant and I devised a successful technique to unknot the tube: the stomach was filled with water just to the point of discomfort, and the knot was allowed to float freely within the dilated organ. Within minutes the knot untied itself and the tube was easily withdrawn. Several years later by chance I came on a frustrated radiologist un- to untie a successfully attempting plain nasogastric tube knotted within a patient's stomach. We distended the stomach with water, and once again, by allowing the knot to expand in three dimensions, it promptly untied itself. Such knotting is unusual, as Morris notes, but when it is sus¬ pected, I suggest this method, easily performed under fluoroscopic control, before attempting forceful and possi¬ bly traumatic withdrawal. Paul D. Larsen, MD Kaiser Permanente Medical Care Program Santa Clara, Calif Polyethylene Tube: Another Knotty Problem To the Editor.\p=m-\Weread with interest the letter by Harold H. Morris III, MD, (237:1432, 1977) regarding a knot formation as a complication in the use of nasogastric intubation. Recently we encountered a similar problem in the use of polyethylene tubing (PT) to rethread peritoneal dialysis catheter (PDC). We have used PT to reinsert PDC if, immediately after insertion of the latter, there is poor or no return of dialysate. Despite taking appropriate precautions, the catheter may be plugged with fibrin, or the return of dialysate may be poor because of mechanical problems. Since the field is sterile, we thread the PT through the PDC, remove the PDC, reinsert an- other catheter, and remove the inner PT. The procedure is simple and by\x=req-\ passes the need for reinsertion of the catheter at another site. Recently, we ran into a problem while reinserting the catheter in a 3\x=req-\ year-old. The PT was passedwaswith reease into PDC, the first PDC moved, and a new one was threaded over PT. The PT could not be re¬ moved, as there was a great deal of resistance on attempted withdrawal. Thus, both PDC and PT had to be re¬ moved, and a knot was found at the end of the tube (Figure). Later, it was realized that about 15.2 cm of PT was threaded beyond the end of PDC; it recurled on itself and formed a knot on attempted removal. There is no need to abandon this simple procedure as long as one takes far precautions to not insert PT too into the peritoneal cavity and one is aware of the potential complication of kink formation. Hari C. Puri, MD University of Oregon Portland Hyperparathyroidism and Medullary Sponge Kidney To the Editor.\p=m-\Thearticle concerning the occurrence of hyperparathyroidism and medullary sponge kidney as presented by Gremillion et al (237:799, 1977) was of interest to me since I have a patient, a 50-year-old woman, who underwent excision of a parathyroid adenoma in April 1969. The intravenous pyelogram also disclosed the presence of brush-like appearance in the pyramidal portion of both kidneys, and this was thought to be consistent with medullary sponge kidneys. In addition, the patient has had numerous bouts of acute renal colic owing to the presence of a number of small calculi in both kidneys. The patient's serum calcium as well as urinary calcium levels have remained within normal limits since her surgery. Her parahormone level has also remained normal. It interests me also that perhaps there is more than just a chance relationship between the occurrence of hyperparathyroid disease and medul- lary sponge kidney. Otto C. Beyer, MD Howard County Medical Center Ellicott City, Md Carbamazepine for Central Sleep Apnea To the Editor.\p=m-\CarbamazepineTegretol), a tricyclic, has been used successfully in trigeminal neuralgia and symppartial seizure with complex tomatology. It has been tried also in the Kluver-Bucy syndrome, hiccups, compulsive water drinking, stammering, psoriasis, Pickwickian syndrome, and diabetic and amyloid neuropathy. Although other tricyclics have been used in the treatment of central sleep apnea,1 I have not found a citation that mentions carbamazepine used for this syndrome. apnea syndromes are more than previously considered.2 I have been treating a patient for partial seizure and complex symp- Sleep numerous tomatology with 1,200 mg/day of carbamazepine with good control of sei- and symptomatology for seven months. The patient sleeps better since I discontinued therapy with phenytoin and began carbamazepine therapy. Usually I see the patient alone; one day I saw the patient with his wife, who remarked that her husband did not snore nor did he "hold his breath" anymore during sleep since he has been using carbamazepine. She could date these changes to zures Polyethylene tubing (PT) threaded through peritoneal dialysis catheter. end of PT. Knot is seen at Downloaded From: http://jama.jamanetwork.com/ by a Florida International University Medical Library User on 05/30/2015