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Acth Levels in Aortocoronary
Bypass Interventions with
Extracorporeal Circulation

Rodríguez, Justino; Corona, Pedro;
Pérez, Miguel Angel; Pérez, José Luis;
Morillas, M. Consolación

Intensive Medical Unit. Clinica "San Roque", Las Palmas G.C.
Intensive Medical Unit, Hospital Militar Central "Gómez Ulla", Madrid, Spain

SUMMARY
Objective: To analyse the variations of the ACTH in interventions of aortocoronary bypass with extracorporeal circulation (CEC) during a period of 5 days.
Methods: A study prospective, without randomiser, selecting 25 patients, all males, to those that in a programmed way an aortocoronary bypass will carry out with CEC. They are excluded those that a basal ACTH presents outside of range. They were carried out 5 extractions of blood. On 1st, the previous day to the surgery; on 2nd ,during the CEC, in the moment of maximum hypothermia; on 3rd, to the arrival to the unit medical intensive; on 4th, next day of the surgery; on 5th, five days later of surgery. The method statistical employee was the Test t Student among the different extractions accepting as significant the values from lowers than p to 0.05.
Results: The results of the different extractions were of 15.32 ± 11.36, 23.68 ± 19.96, 31.78 ± 25.16, 16.62 ± 13.81 and 12.51 ± 9.55. The statistical analysis demonstrated that in spite of an important ascent of the values during the intervention and in the later day to her, only the comparison of the initial values with the ends showed a significance of p = 0,005. These intermediate results didn't show significant differences since being higher they still present a very upper standard deviation due to important interpersonal variations.
Conclusions: An ascent of the ACTH is demonstrated during and after an intervention of aortocoronary bypass. The later descent maintains significantly high the values of ACTH on 5th day postintervention with regard to the basal values.

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INTRODUCTION
   Since the first work on thyroid hormones and extracorporeal circulation published by Taylor and cols, in 1978 to most recent, in general it confirm an alteration in the levels of thyroid hormones and in concrete absence of answer of the TSH in the patients taken part by cardiac surgeons under extracorporeal circulation, These alterations begin during the surgical intervention and still persist 24 hours after the surgery. There are no studies that extend this period.

OBJECTIVE
   To analyse the variations of the ACTH in interventions of bypass aortocoronary with extracorporeal circulation (CEC) during a period of 5 days.

METHOD
   Prospective study, without randomiser, selecting 25 patients, all males, to which of programmed is going away to them to make by-pass aortocoronary with CEC in the Service of Surgery Cardiac of the Central Military Hospital "Gómez Ulla" of Madrid.

   The inclusion criteria were: Men of age upper to 18 years. Euthyroidal clinical and analytical. Programmed surgery. That extracorporeal circulation is used. To admitted alive in UMI. Is made of technical isolated of miocardical revascularización.

   The exclusion criteria were: Administration of Amiodarona in the 30 previous days to the surgical intervention. Administration of betablockers in the 7 previous days to the surgical intervention. Women.

   All the patients were taken part by the same surgical equipment and anaesthetized by the same anaesthetist. During the surgical intervention they were monitored: ECG. Invasive systemic and pulmonary pressure arterial. Cardiac output and mixed venous saturation in pulmonary artery. Pulxiosimetría. Inspiration fraction of oxygen. Tidal end CO2 Inspiration and exhalation concentration of inhaled anesthetic gas. Temperature in systemic blood and vesical. Hourly diuresis.

   Those are excluded that present a basal ACTH outside rank.

   Five takings of blood for the determination of the ACTH were made. 1st takes the previous day to the surgery; 2nd takes during the CEC at the moment from top hypotherm; 3rd takes to the arrival to the UMI; 4th takes the day after the surgery; 5th takes to five days later of the surgery.

   The determinations of TSH are made according to quantitative serum method by means of competitive technique of radio immunoassay, with a rank of measurement of < 0.00025 to 150 microU.I./ml of TSH. The reference ranks went from 0.13 to 4.68 microU.I./ml a specificity < 0,01%.

   The statistical method used was the Test of the t of Student between the different takings, accepting like significant values of p less than to 0.05.

RESULTS
   Following the process determined in the method we have obtained the following values corresponding to the five takings. In first one we obtained an average value of 15,32 with a standard deviation of 11.36. In second taking we observed an average value of 23,68 with a standard deviation of 19.96. In third taking an average value of 31,78 with a standard deviation of 25.16 was obtained. In fourth taking the results presented an average value of 16,62 with a standard deviation of 13,81 and in fifth and completes taking the average values were of 12,51 with a standard deviation of 9.55.

   The application of the Test of the t of Student only showed a significant difference between the initial values and the final values with a meaning of p < 0.005. Although the values showed great modifications we also were with great amplitude in the values of the standard deviations what prevents that the wished degree of meaning is reached.

   The use of Tests less strict would show significant differences but we have wanted to sharpen the maximum of the statistical results to risk of not obtaining sufficiently positive results. In order to analyse the results we must consider that adrenocorticotropic hormone or ACTH this secreted by the anterior pituitary gland and stimulates the adrenal cortex crust to secret glucocorticoids, cortisol... Although this hormone habitually secretes in small amounts this secretion can be seen up to 20 times increased in few minutes in case of stimuli triggered by mechanisms of physiological alarm. The situation of surgical aggression and more even the use of a pump cardiac power the ACTH production as we can see by the obtained results. Nevertheless, we must consider that certain substances as own cortisol causes effects that limit the production of ACTH by a system of negative feedback.

   The important cortisol consumption in these situations causes that as well as we obtain high values of ACTH. This situation can be very beneficial for the patient in critical situations because cortisol power in a very important form diverse metabolic activities as they are the increase of sanguineous amino acids and an increase of the proteinic synthesis in the liver.

   These increases can contribute in a very effective form in the patient submissive by a by-pass coronary since power of very important form their recovery. Nevertheless, we cannot avoid the fact that each individual reacts a very different of the stress surgical and it causes for one important differences to us that they are reflected in standard deviations of greater organization than if we spoke of another type of analytical determinations. On the other hand the fact exists that all the patients do not arrive at the intervention in the same metabolic state reason why the secretion of the ACTH is seen very altered according to the patient is in greater or smaller situation of catabolism. Although neither of our patients present a situation of hepatica insufficiency also we could find great differences interpersonal in case the study were reproduced including this type of patients.

   About summary we can think that at fifth day of the surgical intervention by a by-pass with pump of circulatory attendance the mobilization of the metabolism by cortisol has been so high that it does not need to stay in the previous levels to the intervention where the organism prepared itself for the surgical aggression.

CONCLUSIONS
   As it were foreseeable the ACTH increases during and after an aortocoronary bypass surgical intervention with extracorporeal circulation. Nevertheless, the values do not get to show significant differences during this period due to the high interpersonal variations that are observed. At fifth day of the intervention if we can observe a significant difference the loss with respect to the initial values that if they are significant and that we can attribute to a stabilization of the postsurgical process as well as to certain factors bound to the own situation of the patient like exit of ICU, minor stress by the obtained result.

 

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2nd Virtual Congress of Cardiology

Dr. Florencio Garófalo
Steering Committee
President
Dr. Raúl Bretal
Scientific Committee
President
Dr. Armando Pacher
Technical Committee - CETIFAC
President
fgaro@fac.org.ar
fgaro@satlink.com
rbretal@fac.org.ar
rbretal@netverk.com.ar
apacher@fac.org.ar
apacher@satlink.com

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