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J L Arroyo

Publications and source records attributed to J L Arroyo.

32 records · Page 2Linked to original sources
PubMedDate not supplied

[Depression of the mononuclear phagocyte system caused by high doses of narcotics].

We evaluated in human monocytes the effect of high doses of alfentanyl on the expression of vimentin filaments, the phagocytic activity and the membrane display of HLA-DR molecules in the subjects undergoing surgery. The study was performed on 30 patients, ASAI-II. The patients received 100 mcg/kg i.v. of Alfentanil and the maintenance of anaesthesia was made with Alfentanil (2-3 mcg/kg/min.). The patients were randomized in two groups. The patients were ventilated with N2O:O2 (1:1) (Group I) or air: O2 (1:1) (Group II). After surgery, all patients of the Group II received Naloxone (0.2-0.4 mg). Central venous blood samples were obtained before induction, one and two hours after induction of anaesthesia and at the end of surgery. Separation of monocytes was performed according to Boyum technique. CD35 and HLA-DR molecules and vimentin filaments were studied by indirect immunofluorescence method using monoclonal antibodies. Percentage of positive cells were read with a cytofluorometer. The phagocytic function of monocytes was determined by ingestion of latex particles. Cortisol and ACTH plasma levels were determined by RIA. High doses of Alfentanyl depress phagocytic function and membrane display of CD35 and HLA-DR molecules in monocyte and induce marked changes in the organization of vimentin filaments in these cells in patients undergoing surgery. This monocytic depression was more marked in the patients ventilated with N2O. In our results there was uninhibition of ACTH and cortisol plasma levels responses to surgical stress by Alfentanil administration. Since the effects of Alfentanil were reversed by Naloxone, an opioid receptor mechanism seems to mediate these events.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

[Midazolam in anesthesiology].

Midazolam (MDZ) (8-chloro-6(2-fluoropheny 1)-1-methyl-4H-imidazol-[1,5a] [1,4]benzodiazepine) is an "annelated" benzodiazepine (BZDs) synthetized in 1976, characterized differently with the "classical" BZDs by a five-membered heterocycle fused on position 1,2 of the diazepine nucleus. This fused imidazol ring modifies the properties inherent in the "classical" BZDs in at the least three aspects: solubility, metabolisation and the stability in aqueous solution. MDZ, having similar properties with the "classical" benzodiazepines, has better local tolerance, faster onset of action, greater plasmatic clearance, shorter half-life elimination (1.7-2.4 hr) with no active metabolites. With a bioavailability of 92% (IV), 82-91% (IM) and 50-52% "per os", the CNS effects of MDZ are similar in all three ways. In anesthesiology we can administer MDZ as an anesthetic premedication ("per os", IM or IV), anesthetic induction and maintenance and IV sedation in locorregional anesthetic procedures or diagnostic and therapeutic explorations. MDZ has a great safety margin, moderate respiratory and cardiovascular effects and lacks of teratogenic or embryotoxic effects.

Anesthesia, Intravenous↗
PubMedDate not supplied

[A bupivacaine-morphine combination by intrathecal route: correlation between pain relief and postoperative neuroendocrine response].

The purpose of the present study was to assess the repercussion of morphine injected in the intrathecal space on postoperative neuroendocrine response and the correlation with pain relief in the postop period. We studied 50 healthy patients (ASA I-II) submitted to orthopaedic surgery under general anaesthesia (N = 25) or spinal anaesthesia (N = 25). In the group under general anaesthesia we observed a hypersecretion of ADH, ACTH, cortisol and aldosterone during and after surgery. In the group un spinal anaesthesia, it was evident, on the contrary, a blockade of the neuroendocrine response during surgery, as well as an attenuation during postoperative period. Intraoperative and postoperative bleeding with spinal anaesthesia was significantly lower (p less than 0.01; p less than 0.05 respectively) than with general anaesthesia. Postoperative analgesia was excellent in group with spinal anaesthesia; the average duration of analgesia was 16.3 hours. We conclude that small intrathecal doses of morphine have beneficial effects and may be used usefulness in orthopaedic surgery.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

[Analgesics and neuroendocrinic response in cardiac surgery. I. Adrenal cortex response].

In 91 patients who had undergone surgery under C.E.C. the influence of the analgesia on adrenal cortex system was studied. With the exception of the analgesic used, the anaesthesia was performed following the same guidelines in all of the operations. Concentrations of cortisol in plasma were maximum with Pentazocina, the weakest analgesic used by us, and minimum with Fentanest. In view of these results, we can affirm that, in the absence of alterations haemodynamic, metabolic and neurological, concentrations of cortisol in plasma are a true reflexion of the amount of analgesic protection that different drugs offer against noxins stimuli triggered by the surgical act. These findings guarantee the intimate relationship that exists between the nervous system and the endocrine system and they are further confirmed by results obtained with a recently acquired analgesic Fentathienil, which is more potent than Fentanyl.

Analgesics↗
PubMedDate not supplied

[Does propofol have advantages over midazolam and isoflurane? Comparative study of 2 total intravenous anesthesia techniques using midazolam and propofol, versus balanced anesthesia with isoflurane].

OBJECTIVES: To compare two techniques for total intravenous anesthesia (TIVA): midazolam-alfentanil-flumazenil and propofol-alfentanil, contrasting them with combined anesthesia (thiopental-isoflurane-alfentanil) and assessing the efficacy of flumazenil in continuous perfusion for preventing resedation in TIVA with midazolam. PATIENTS AND METHODS: The efficacy and clinical tolerance of the 3 anesthetic techniques with propofol, midazolam or isoflurane were studied in 63 patients undergoing elective breast, lumbar or gynecological surgery. Anesthetic induction was achieved with midazolam 0.3 mg/kg-1 (group M), propofol 2.5 mg/kg-1 (group P) or thiopental 3 mg/kg-1 (group I); all patients also received 50 micrograms/kg-1 alfentanil and vecuronium bromide 0.12 mg/kg-1/h-1. Maintenance was achieved with midazolam in perfusion at 0.12 mg/kg-1/h-1 (group M); propofol in perfusion at 7 mg/kg-1/h-1 and a pre-incision dose of 1.5 mg/kg-1 (group P); and isoflurane at 1.15% (group I). The 3 groups also received one pre-incision dose of alfentanil 25 micrograms/kg-1 and post-incision perfusion at 60 micrograms/kg-1/h-1. The infusion of alfentanil was changed by amounts of 20 micrograms/kg-1/h-1 in accordance with the patient's response to surgery. After surgery patients in group M received flumazenil 0.5 mg i.v. over 30 sec and a perfusion of flumazenil 0.5 mg over 60 min. Parameters indicating efficacy were: 1) total dose and timing of alfentanil; 2) number of instances of inadequate anesthesia; 3) peri-operative amnesia; 4) times of awakening and extubation after surgery, and 5) the number of patients in each group who required naloxone. Parameters indicating tolerance were: 1) hemodynamic variables; 2) the number of postoperative desaturations; 3) level of sedation, comprehension and motor coordination and orientation; 4) the "G/g detection" test and the memory recall test; 5) adverse side effects; 6) need for postoperative analgesia, and 7) evaluation of the anesthetic technique. RESULTS: The 3 techniques afforded effective control of hemodynamic response to intubation and surgical incision. Anesthetic maintenance was easy and safe with isoflurane and propofol. Higher doses of alfentanil, however, were needed with midazolam and we found a higher incidence of signs of superficial anesthesia. Reversion of midazolam with flumazenil 0.5 mg i.v. produced earlier awakening, although this was followed later by relapse into hypno-sedation that could not be prevented with a perfusion of flumazenil. Although recovery from anesthesia was slower with propofol than with isoflurane, we observed no differences in level of sedation, motor coordination and postoperative comprehension. Maintenance with isoflurane produced a higher incidence of adverse side effects such as tremors and nausea after surgery. CONCLUSIONS: None of the TIVA techniques proved superior in all the parameters studied during anesthetic maintenance when compared with balanced isoflurane-alfentanil, although the propofol-alfentanil combination was found to be superior to that of midazolam-alfentanil. After anesthesia, however, recovery was better with the association of propofol-alfentanil and adverse side effects were fewer. Flumazenil at the doses used was ineffective for preventing resedation due to midazolam.

Adolescent↗
PubMedDate not supplied

[Comparison of the effects of isoflurane and alfentanyl on the mononuclear-phagocytic system].

BACKGROUND AIMS: The effects of two anesthetic agents, alfentanil and isoflurane, on the macrophage-monocytic system and the relation with the adrenocortical-hypophyseal axis were analyzed. MATERIAL AND METHODS: Thirty ASA I-II patients submitted to elective surgery were distributed into two groups: group I, analgesic anesthesia with alfentanil 100 micrograms/kg, a perfusion of 2-3 micrograms/kg/min and naloxone 0.2-0.4 mg upon termination of surgery; group II, inhalation anesthesia with isoflurane at 2-2.5% and O2/air = 1/1. HLA-DR membrane receptors and vimentin threads of the cytoskeleton were determined in basal conditions, at one hour and two hours of induction and upon termination of surgery by means of indirect immunofluorescence with the use of monoclonal antibodies. Phagocytosis of latex particles was also measured and ACTH and cortisol levels were obtained by radioimmunoassay. RESULTS: In group I (alfentanil) a decrease (p < 0.01) of all the monocyte parameters analyzed, which was more significant than that observed in group II (isoflurane), was observed. In group II only the expression of HLA-DR and the index of phagocytosis (p < 0.05) were statistically significant. Following the administration of naloxone a reversion of these parameters was observed. The maximum immune depression corresponded with the lowest values of ACTH and cortisol (group I) with surgical stress being discarded as the cause of this immunodepression. CONCLUSIONS: Alfentanil produces a monocytic depression which reverses following the administration of naloxone, thus discarding surgical stress as the cause of this immunodepression suggesting a mechanism mediated by opiate receptors. With regards to isoflurane, the functions of the mononuclear-phagocytic system were hardly altered in the patient studied.

Adrenocorticotropic Hormone↗