Interactive Cardiovascular and Thoracic Surgery 3:309-310(2004)
© 2004 European Association of Cardio-Thoracic Surgery
Case report - Cardiac general |
Temporary stupor in a patient treated with iodoform gauze for mediastinitis after coronary artery bypass grafting
Satoshi Numata*,
Yuichiro Murayama,
Masahiro Makino and
Akiteru Nakamura
Department of Cardiovascular Surgery, Kyoto First Red Cross Hospital, Higashiyama, Kyoto 605-0981, Japan
* Corresponding author. Tel.: +81-75-561-1121; fax: +81-75-561-6308
satnumata{at}yahoo.co.jp
Received December 18, 2003;
received in revised form January 7, 2004;
accepted January 12, 2004
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Abstract
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Irrigation and packing with iodoform gauze are often employed for the treatment of mediastinitis after heart surgery. Using this procedure we experienced a case of a patient, who suffered from iodine toxicity. The patient was a 78-year-old male who underwent off-pump coronary artery grafting, using bilateral internal mammary artery. He suffered from mediastinitis and was treated with irrigation and packing with iodoform gauze. The patient gradually entered into a stupor. Brain computed tomography revealed no abnormal findings. However, the serum iodine concentration was significantly high. Therefore, we stopped the iodoform gauze packing, and the neurological findings improved as the serum iodine concentration decreased.
Key Words: Iodine toxicity; Mediastinitis; Stupor
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1. Patient
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The patient was a 78-year-old man who had been treated previously for hypertension and diabetes. The patient complained of sudden chest pain at midnight, and was admitted to our hospital. Coronary angiography revealed 90% stenosis of the left main trunk. Left ventriculography showed akinesis of anterior-septal wall. Left ventricular end-diastolic volume index was 80.7 ml/m2. Left ventricular end-systolic volume index was 45.8 ml/m2. Left ventricular ejection fraction was 43%. Emergency intra-aortic balloon pumping was indicated. The operation was performed through a median sternotomy. The left internal mammary artery was anastomosed to the left anterior descending artery, and the right internal mammary artery was anastomosed to the obtuse marginal branch, as a composite graft without cardiopulmonary bypass. The patient was extubated on the second postoperative day and the intra-aortic balloon was removed on the third postoperative day. However, the patient often needed sedative drugs for his delirium, and frequently coughed up sputum. The reinitiation of oral intake was prolonged, and controlling blood sugar was difficult due to the diabetes. On the 15th postoperative day, dehiscence of the median wound was observed and a purulent discharge was drained. The sternal bone was also detached. The discharge culture grew methicillin-resistant Staphylococcus aureus (MRSA). Mediastinal debridement and transposition of the major omentum were carried out on the 29th postoperative day. The sternal bone remained detached, because infection of sternal bone was very severe. Only the skin was closed. Eighteen days after the transposition, wound dehiscence again occurred and we had to open the whole chest wound for drainage. At this time the patient did not need the respirator and was able to ingest sufficient food and fluids orally. We therefore treated this wound with irrigation with 500 ml saline and packed it with two iodoform gauze sheets (each sheet contained 11 mg iodine, TAMAGAWA®), twice a day. Because the discharge culture grew MRSA, we wanted to close the wound after the culture becomes negative. Following this treatment, the patient gradually became unresponsive and consciousness became cloudy. Twenty-six days after introducing the iodoform gauze, the patient finally entered into a stupor, and conjugate deviation, involuntary motion of lower extremities, and abnormal muscle tone of upper extremities were observed. However, the patient's blood pressure and respiratory status remained stable. Brain computed tomography revealed no different findings compared with previous ones. Serum iodine was found to be very high (715 µg/dl). Urinary iodine was also high (3930 µg/dl). We therefore suspected that the cause of the stupor was related to iodine toxicity. We treated the wound with simple irrigation and packing with untreated gauze. Following treatment without iodine for 30 days, the patient gradually became more reactive as serum iodine levels decreased (serum 30.9 µg/dl, urine 180 µg/dl). Seventy days after we stopped using iodoform gauze, the patient recovered fully neurologically, and no neurological deficits were found. One hundred and forty three days after the first ometum flap, we attempted wound closure with remnant omental tissue. Sixteen days after the operation, patient entered.
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2. Comment
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Since the initial report of Thurer et al. [1], continuous povidone–iodine irrigation or gauze packing with povidone–iodine has often been used to treat mediastinitis after median sternotomy. These procedures are safe and povidone–iodine has a broad antimicrobial spectrum with no tendency to produce bacterial resistance. However, these procedures can induce iodine toxicity, because the amount of iodine absorbed depends upon the concentration of the solution and the route of administration, through mucosal surfaces, rather than through skin.
Iodine toxicity during mediastinal wound dressing with povidone–iodine can occur, either due to absorption of large quantities of iodine in the mediastinum or inadequate clearance as a result of renal dysfunction. Treatment of burns, surgical wounds or ulcers with povidone–iodine can also result in iodine toxicity [2]. The signs and symptoms reportedly caused by iodine toxicity include hypernatremia, hyperchloremia, metabolic acidosis, liver dysfunction, renal dysfunction, thyroid suppression, and mental status change [2–5].
There are several reports of iodine toxicity by continuous povidone–iodine irrigation [2–5]. However, there have been no reports of iodine toxicity as a result of iodine gauze packing alone. The present case suffered from iodine toxicity as a result of treatment with four pieces of iodoform gauze per day for 1 month. Although each piece of iodoform gauze contains 11 mg iodine, we generally treat mediastinal wounds with 44 mg iodine per day. While all the iodine could not likely be absorbed, continuous irrigation of the mediastinum requires about 10–12 g pividone–iodine per day [2,3]. The amount of absorbed iodine with the iodoform gauze procedure may be less than that with the continuous irrigation method. Simultaneously, antibiotics (Vancomycin®) are generally used to treat the infection. After the second operation, the serum creatinine level was 1.25 mg/dl. Two weeks after introducing Vancomycin®, creatinine increased to 3.31 mg/dl (Fig. 1). Thus, renal dysfunction may have allowed the iodine toxicity to become more serious.
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Fig. 1 Clinical course and serum creatinine and iodine concentration. VCM, vancomycin; CABG, coronary artery bypass grafting.
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In future, we will avoid prolonged use of iodoform gauze in patients with mediastinitis, especially with reduced renal function. When iodoform gauze is used, frequent serum iodine levels should be measured to prevent iodine toxicity.
doi:10.1016/j.icvts.2004.01.005
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References
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- Thrurer RJ, Bognolo D, Vargas A. The management of mediastinal infection following cardiac surgery: an experience utilizing continuous irrigation with povidone–iodine. J Thorac Cardiovasc Surg. 1974;68:962–967[Medline]
- Kanakiriya S, De Chazal I, Nath KA, Haugen EN, Albright RC, Juncos LA. Iodine toxicity treated with hemodialysis and continuous venovenous hemodiafiltration. Am J Kidney Dis. 2003;41(3):702–708[CrossRef][Medline]
- Campistol JM, Abad C, Nogue S, Bertran A. Acute renal failure in a patient treated by continuous povidone–iodine mediastinal irrigation. J Cardiovasc Surg (Torino). 1988;29(4):410–412[Medline]
- Zec N, Donovan JW, Aufiero TX, Kincaid RL, Demers LM. Iodine toxicity treated with continuous povidone–iodine mediastinal irrigation. N Engl J Med. 1992;326:1784[Medline]
- Glick PL, Guglielmo BJ, Tranbaugh RF, Turley K. Iodine toxicity in a patient treated by continuous povidone–iodine mediastinal irrigation. Ann Thorac Surg. 1985;39:478–480[Abstract]
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Abstract
1. Patient