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Effect of cardiopulmonary bypass on thyroid function
Ann Thorac Surg 1995;59:1272-8
Fig 1. Chest computed tomographic scan showing the thickened pericardium (between arrows).
computed tomographic scan demonstrated that the pericardium was thickened markedly all around (Fig 1). To exclude infection around the pulse generator and leads, the pericardial cavity was reentered through the same incision. There was no infection around the pacemaker system. The pericardial cavity contained only a small amount of bloody fluid, smears and cultures of which were sterile. The pericardium adhered loosely with thickening. Skin patch tests were negative for titanium, polyurethane, and silicone. Viral tests were negative. We diagnosed this case as postpericardiotomy syndrome, a n d administration of loxoprofen sodium, 180 m g a day by mouth, was started. The chest pain and fever were relieved for the subsequent 3 weeks. A chest computed tomographic scan performed 6 weeks after the operation showed that the thickening of the pericardium had disappeared (Fig 2). The postpericardiotomy syndrome first was described as the postcommissurotomy syndrome by Soloff a n d associates in 1953 [1], and it became clear that this syndrome could occur after any operation that involved opening the pericardium [2]. Although
CORRESPONDENCE
1273
viral tests were negative in the case presented herein, we suggest that the syndrome was due to an immunologic response and a viral infection [3, 4]. Heart-reactive antibodies in the serum and titers to one or more viral agents are particularly higher in one-fourth of patients in w h o m this syndrome develops [3, 4]. Clinically, symptoms consist primarily of fever and chest pain [5], which appear a few weeks to a few months after cardiac operation with a median postoperative time of onset of 4 weeks [6]. The syndrome is self-limiting, a n d recurrences are c o m m o n [6]. We speculate that the thickened pericardium demonstrated on the chest computed tomographic scan may represent an overreactive healing precess of the damaged pericardial tissue. Blood and its products superimposed on injured pericardial surfaces occasionally may lead to pericardial adhesions with thickening [7]. The fact that thickening of the pericardium vanished as the syndrome improved supports our speculation. We believe that postpericardiotomy syndrome after pacemaker implantation is a rare condition; however, a chest computed tomographic scan is helpful to make a diagnosis and differentiate this condition from pacemaker infection.
Yasushi Terada, MD Toshio Mitsui, MD Yuichiro Kaminishi, MD Yukihiro Yoshimura, MD Institute of Clinical Medicine University of Tsukuba Hospital University of Tsukuba Tsukuba, Ibaraki-ken 305, Japan References 1. Soloff LA, Zatuchui J, Janton OH, O'Neill TJE, Glover RP. Reactivation of rheumatic fever following mitral commissurotomy. Circulation 1953;8:481-93. 2. Ito T, Engle MA, Goldberg HP. Postpericardiotomy syndrome following surgery for non-rheumatic heart disease. Circulation 1958;17:549-56. 3. Engle MA, McCabe JC, Ebert PA, Zabriskie JB. The postpericardiotomy syndrome a n d antiheart antibodies. Circulation 1974;49:401- 6. 4. Engle MA, Zabriskie JB, Senterfit LB, Gay WA Jr, O'Loughlin JE, Ehlers KH. Viral illness and the postpericardiotomy syndrome: a prospective study in children. Circulation 1980;62: 1151-8. 5. Kirsh MM, McIntosh K, Kahn DR, Sloan H. Postpericardiotomy syndromes. A n n Thorac Surg 1970;9:158-79. 6. Nishimura RA, Fuster V, Burgert SL, Puga FJ. Clinical features and long-term natural history of the postpericardiotomy syndrome. Int J Cardiol 1983;4:443-54. 7. Cliff WJ, Grobety J, Ryan GB. Postoperative pericardial adhesions. The role of mild serosal injury and spilled blood. J Thorac Cardiovasc Surg 1973;65:744-50.
Effect of Cardiopulmonary Bypass on Thyroid Function To the Editor:
Fig 2. Chest computed tomographic scan performed after the syndrome improved showed that thickening of the pericardium vanished. © 1995 by The Society of Thoracic Surgeons
We read with the highest interest the article by Dr Jones and colleagues entitled "Should Thyroid Function Be Assessed Before Cardiopulmonary Bypass Operation?" [1]. It is very interesting and it pointed out an important problem about the correct preoperative assessment of patients with depressed thyroid function. We would like to present our experience and our results. We investigated free triiodothyronine (fT3) and free thyroxine (IT4) changes during cardiopulmonary bypass (CPB) in 30 con0003-4975/95l$9.50
1274
CORRESPONDENCE
Ann Thorac Surg 1995;59:1272-8
Table 1. Effect of Cardiopulmonary Bypass Operation on Serum Free Thyroxine and Thyroid-Stimulating Hormone Levels 24 Hours Postoperatively" Free Thyroxine (pmol/L)
Patient
TSH (mlU/L)
No.
Sex
Preop
Postop
Preop
Postop
1 2 3 4 5 6 7 8 9 10 11
M M M M M M F F M M M
20.5 18.5 24.2 19.5 16.1 22.1 20.6 15.1 15.2 17.6 20.4
8.9 12 14 13.9 10.8 11.1 12.4 13 12.2 11.7 18.8
1.3 1.5 1.8 2 1.7 3.7 3.2 2.7 1.6 2.2 1.6
1.3 1.8 0.8 3.2 0.2 1.7 1 2.1 2.4 4.5 0.3
a Normal ranges: free thyroxine, 11 to 24 pmol/L; TSH (female), 0.38 to 4.8 mlU/L; TSH (male), 0.45 to 3.4 mIU/L. TSH - thyroid-stimulating hormone.
who manifest the euthyroid sick syndrome also is controversial [31. Taken together, the clinical and laboratory data are suggestive of a possible new avenue to treat or prevent low cardiac output after CPB. If low concentrations of triiodothyronine and fT3 have physiologic significance, it will be necessary to determine which patients may benefit. In the elderly population and in patients requiring correct assessment of thyroid function, serum thyroxine levels should be evaluated routinely before operation, intraoperatively (before and after CPB), and at 24 hours postoperatively. Until more evidence is available, we believe, as Dr Jones and associates propose, that the potential benefit of this simple, safe, and inexpensive method should not be withheld.
Roberto Scrofani, MD Maurizio Salati, MD Carmine SantolL MD Divisione di Chirurgia Toracica E Cardiovascolare Ospedale "'Luigi Sacco'" Via G.B. Grassi n. 74 20157 Milano Italy References
secutive patients. All operations were performed on an elective basis, and uniform anesthesia, CPB conduct, and myocardial protection were used in all patients. Preoperatively, 1 patient was receiving amiodarone therapy. Blood samples for hormone assays were collected before operation, shortly (within 2 minutes) after the induction of CPB, and immediately before discontinuation of bypass to avoid the interference of hemodilution or heparinization. On the whole, we did not find a significant difference between fT 3 and fT~ at the beginning and at the end of CPB. The fir 3 concentrations (normal values, 2.8 to 5.6 pg/mL) varied from 4.2 + 0.5 to 4.3 ± 0.6 pg/mL (p - not significant), and the tT 4 concentrations (normal values, 6.6 to 14.0 pg/mg) varied from 17.8 + 4.1 to 18.3 + 3.4 mg/mL (p = not significant). Free triiodothyronine values decreased during CPB in 15 patients, whereas in the other 15 fT3 concentration rose or remained unvaried. We did not observe significant differences between the two groups of patients with regard to preoperative, intraoperative (CPB time, coagulation time, hematocrit value), and postoperative (rewarming time, hemodynamic instability, ventricular arrhythmia) clinical data. Only the patient receiving amiodarone therapy had a serious decrease (under the normal range in fT3 level), but the postoperative course was uneventful. Interestingly, the f T 4 levels were already above the normal range in 26 patients at the beginning of CPB and remained high throughout CPB. These findings agree with the observation of Bremmer and colleagues [2] that attributed the increase in fT4 values to heparin displacement of cellular binding of thyroxine. By inhibiting the output of thyroid-stimulating hormone, these high levels of fT4 may block a compensatory response by hypothalamo-tbyroid axis after CPB and probably after the operation. Thyroid abnormalities influence cardiac function in a variety of clinical settings. The hemodynamic effects of thyroid hormones are well documented and include effects on contractility, heart rate, and myocardial oxygen consumption [3]. Triiodothyronine may act as inotropic agent stimulating the adenyl-cyclase in myocardium [4], but caution must be used in recommending triiodothyronine therapy as "replacement therapy" in patients undergoing cardiac operations. Administration of T3 in patients
1. Jones TH, Hunter SM, Price A, Angelini GD. Should thyroid function be assessed before cardiopulmonary bypass operation? Ann Thorac Surg 1994;58:434-6. 2. Bremmer WF, Taylor KM, Baird S, et al. Hypothalamopituitary-thyroid axis function during cardiopulmonary bypass. J Thorac Surg 1978;75:392-9. 3. Holland FV II, Brown PS Jr, Weintraub BD, Clark RE. Cardiopulmonary bypass and thyroid function: "euthyroid sick syndrome". Ann Thorac Surg 1991;52:46-50. 4. Levey GS. Catecholamine sensitivity, thyroid hormone and the heart: a reevaluation. Am J Med 1971;50:415-20.
Reply To the Editor: We thank Drs Scrofani, Salati, and Santoli for reemphasizing that assessment of thyroid function should be considered before elective cardiopulmonary bypass operations. We must state that those patients with a history of thyroid disease, whether or not they are receiving thyroxine replacement and amiodarone therapy, should have mandatory testing before operation. It is well known that initiation of thyroxine therapy may exacerbate angina, and treatment therefore has to be introduced gradually using small doses at first, building up slowly to the full replacement dose. In view of this the clinician will have to weigh the benefits of replacing thyroxine against the risks of delaying operation in each individual patient, bearing in mind that no clear perioperative complication of patients with untreated hypothyroidism has been demonstrated. Doctor Scrofani and colleagues found two groups of patients, one in which there was a fall in free T3 levels during operation and a second with either no change or a slight increase in levels. We wanted to point out that the maximal suppression of thyroid hormone levels is observed during the postoperative period. Table 1 shows the differences between free T 4 and thyroidstimulating hormone levels before and 24 hours after operation (fT3 was not measured) in patients with normal preoperative thyroid function. In the majority of patients there were signifi-
Fig 1. Chest computed tomographic scan showing the thickened pericardium (between arrows).
computed tomographic scan demonstrated that the pericardium was thickened markedly all around (Fig 1). To exclude infection around the pulse generator and leads, the pericardial cavity was reentered through the same incision. There was no infection around the pacemaker system. The pericardial cavity contained only a small amount of bloody fluid, smears and cultures of which were sterile. The pericardium adhered loosely with thickening. Skin patch tests were negative for titanium, polyurethane, and silicone. Viral tests were negative. We diagnosed this case as postpericardiotomy syndrome, a n d administration of loxoprofen sodium, 180 m g a day by mouth, was started. The chest pain and fever were relieved for the subsequent 3 weeks. A chest computed tomographic scan performed 6 weeks after the operation showed that the thickening of the pericardium had disappeared (Fig 2). The postpericardiotomy syndrome first was described as the postcommissurotomy syndrome by Soloff a n d associates in 1953 [1], and it became clear that this syndrome could occur after any operation that involved opening the pericardium [2]. Although
CORRESPONDENCE
1273
viral tests were negative in the case presented herein, we suggest that the syndrome was due to an immunologic response and a viral infection [3, 4]. Heart-reactive antibodies in the serum and titers to one or more viral agents are particularly higher in one-fourth of patients in w h o m this syndrome develops [3, 4]. Clinically, symptoms consist primarily of fever and chest pain [5], which appear a few weeks to a few months after cardiac operation with a median postoperative time of onset of 4 weeks [6]. The syndrome is self-limiting, a n d recurrences are c o m m o n [6]. We speculate that the thickened pericardium demonstrated on the chest computed tomographic scan may represent an overreactive healing precess of the damaged pericardial tissue. Blood and its products superimposed on injured pericardial surfaces occasionally may lead to pericardial adhesions with thickening [7]. The fact that thickening of the pericardium vanished as the syndrome improved supports our speculation. We believe that postpericardiotomy syndrome after pacemaker implantation is a rare condition; however, a chest computed tomographic scan is helpful to make a diagnosis and differentiate this condition from pacemaker infection.
Yasushi Terada, MD Toshio Mitsui, MD Yuichiro Kaminishi, MD Yukihiro Yoshimura, MD Institute of Clinical Medicine University of Tsukuba Hospital University of Tsukuba Tsukuba, Ibaraki-ken 305, Japan References 1. Soloff LA, Zatuchui J, Janton OH, O'Neill TJE, Glover RP. Reactivation of rheumatic fever following mitral commissurotomy. Circulation 1953;8:481-93. 2. Ito T, Engle MA, Goldberg HP. Postpericardiotomy syndrome following surgery for non-rheumatic heart disease. Circulation 1958;17:549-56. 3. Engle MA, McCabe JC, Ebert PA, Zabriskie JB. The postpericardiotomy syndrome a n d antiheart antibodies. Circulation 1974;49:401- 6. 4. Engle MA, Zabriskie JB, Senterfit LB, Gay WA Jr, O'Loughlin JE, Ehlers KH. Viral illness and the postpericardiotomy syndrome: a prospective study in children. Circulation 1980;62: 1151-8. 5. Kirsh MM, McIntosh K, Kahn DR, Sloan H. Postpericardiotomy syndromes. A n n Thorac Surg 1970;9:158-79. 6. Nishimura RA, Fuster V, Burgert SL, Puga FJ. Clinical features and long-term natural history of the postpericardiotomy syndrome. Int J Cardiol 1983;4:443-54. 7. Cliff WJ, Grobety J, Ryan GB. Postoperative pericardial adhesions. The role of mild serosal injury and spilled blood. J Thorac Cardiovasc Surg 1973;65:744-50.
Effect of Cardiopulmonary Bypass on Thyroid Function To the Editor:
Fig 2. Chest computed tomographic scan performed after the syndrome improved showed that thickening of the pericardium vanished. © 1995 by The Society of Thoracic Surgeons
We read with the highest interest the article by Dr Jones and colleagues entitled "Should Thyroid Function Be Assessed Before Cardiopulmonary Bypass Operation?" [1]. It is very interesting and it pointed out an important problem about the correct preoperative assessment of patients with depressed thyroid function. We would like to present our experience and our results. We investigated free triiodothyronine (fT3) and free thyroxine (IT4) changes during cardiopulmonary bypass (CPB) in 30 con0003-4975/95l$9.50
1274
CORRESPONDENCE
Ann Thorac Surg 1995;59:1272-8
Table 1. Effect of Cardiopulmonary Bypass Operation on Serum Free Thyroxine and Thyroid-Stimulating Hormone Levels 24 Hours Postoperatively" Free Thyroxine (pmol/L)
Patient
TSH (mlU/L)
No.
Sex
Preop
Postop
Preop
Postop
1 2 3 4 5 6 7 8 9 10 11
M M M M M M F F M M M
20.5 18.5 24.2 19.5 16.1 22.1 20.6 15.1 15.2 17.6 20.4
8.9 12 14 13.9 10.8 11.1 12.4 13 12.2 11.7 18.8
1.3 1.5 1.8 2 1.7 3.7 3.2 2.7 1.6 2.2 1.6
1.3 1.8 0.8 3.2 0.2 1.7 1 2.1 2.4 4.5 0.3
a Normal ranges: free thyroxine, 11 to 24 pmol/L; TSH (female), 0.38 to 4.8 mlU/L; TSH (male), 0.45 to 3.4 mIU/L. TSH - thyroid-stimulating hormone.
who manifest the euthyroid sick syndrome also is controversial [31. Taken together, the clinical and laboratory data are suggestive of a possible new avenue to treat or prevent low cardiac output after CPB. If low concentrations of triiodothyronine and fT3 have physiologic significance, it will be necessary to determine which patients may benefit. In the elderly population and in patients requiring correct assessment of thyroid function, serum thyroxine levels should be evaluated routinely before operation, intraoperatively (before and after CPB), and at 24 hours postoperatively. Until more evidence is available, we believe, as Dr Jones and associates propose, that the potential benefit of this simple, safe, and inexpensive method should not be withheld.
Roberto Scrofani, MD Maurizio Salati, MD Carmine SantolL MD Divisione di Chirurgia Toracica E Cardiovascolare Ospedale "'Luigi Sacco'" Via G.B. Grassi n. 74 20157 Milano Italy References
secutive patients. All operations were performed on an elective basis, and uniform anesthesia, CPB conduct, and myocardial protection were used in all patients. Preoperatively, 1 patient was receiving amiodarone therapy. Blood samples for hormone assays were collected before operation, shortly (within 2 minutes) after the induction of CPB, and immediately before discontinuation of bypass to avoid the interference of hemodilution or heparinization. On the whole, we did not find a significant difference between fT 3 and fT~ at the beginning and at the end of CPB. The fir 3 concentrations (normal values, 2.8 to 5.6 pg/mL) varied from 4.2 + 0.5 to 4.3 ± 0.6 pg/mL (p - not significant), and the tT 4 concentrations (normal values, 6.6 to 14.0 pg/mg) varied from 17.8 + 4.1 to 18.3 + 3.4 mg/mL (p = not significant). Free triiodothyronine values decreased during CPB in 15 patients, whereas in the other 15 fT3 concentration rose or remained unvaried. We did not observe significant differences between the two groups of patients with regard to preoperative, intraoperative (CPB time, coagulation time, hematocrit value), and postoperative (rewarming time, hemodynamic instability, ventricular arrhythmia) clinical data. Only the patient receiving amiodarone therapy had a serious decrease (under the normal range in fT3 level), but the postoperative course was uneventful. Interestingly, the f T 4 levels were already above the normal range in 26 patients at the beginning of CPB and remained high throughout CPB. These findings agree with the observation of Bremmer and colleagues [2] that attributed the increase in fT4 values to heparin displacement of cellular binding of thyroxine. By inhibiting the output of thyroid-stimulating hormone, these high levels of fT4 may block a compensatory response by hypothalamo-tbyroid axis after CPB and probably after the operation. Thyroid abnormalities influence cardiac function in a variety of clinical settings. The hemodynamic effects of thyroid hormones are well documented and include effects on contractility, heart rate, and myocardial oxygen consumption [3]. Triiodothyronine may act as inotropic agent stimulating the adenyl-cyclase in myocardium [4], but caution must be used in recommending triiodothyronine therapy as "replacement therapy" in patients undergoing cardiac operations. Administration of T3 in patients
1. Jones TH, Hunter SM, Price A, Angelini GD. Should thyroid function be assessed before cardiopulmonary bypass operation? Ann Thorac Surg 1994;58:434-6. 2. Bremmer WF, Taylor KM, Baird S, et al. Hypothalamopituitary-thyroid axis function during cardiopulmonary bypass. J Thorac Surg 1978;75:392-9. 3. Holland FV II, Brown PS Jr, Weintraub BD, Clark RE. Cardiopulmonary bypass and thyroid function: "euthyroid sick syndrome". Ann Thorac Surg 1991;52:46-50. 4. Levey GS. Catecholamine sensitivity, thyroid hormone and the heart: a reevaluation. Am J Med 1971;50:415-20.
Reply To the Editor: We thank Drs Scrofani, Salati, and Santoli for reemphasizing that assessment of thyroid function should be considered before elective cardiopulmonary bypass operations. We must state that those patients with a history of thyroid disease, whether or not they are receiving thyroxine replacement and amiodarone therapy, should have mandatory testing before operation. It is well known that initiation of thyroxine therapy may exacerbate angina, and treatment therefore has to be introduced gradually using small doses at first, building up slowly to the full replacement dose. In view of this the clinician will have to weigh the benefits of replacing thyroxine against the risks of delaying operation in each individual patient, bearing in mind that no clear perioperative complication of patients with untreated hypothyroidism has been demonstrated. Doctor Scrofani and colleagues found two groups of patients, one in which there was a fall in free T3 levels during operation and a second with either no change or a slight increase in levels. We wanted to point out that the maximal suppression of thyroid hormone levels is observed during the postoperative period. Table 1 shows the differences between free T 4 and thyroidstimulating hormone levels before and 24 hours after operation (fT3 was not measured) in patients with normal preoperative thyroid function. In the majority of patients there were signifi-