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Biomedical subjects

G Roca

Publications and source records attributed to G Roca.

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

Crystalline dihydrotestosterone implants in the lateral septum of male rats. A positive effect on LH and FSH.

Previous investigations in our laboratory have shown that testosterone implanted into the lateral septum in male rats increases LH and FSH secretion. However, it was unclear whether the effect of testosterone was direct via androgen receptor, or indirect via the estrogen receptor after conversion by aromatization to estradiol. To answer this question, we implanted either testosterone or the non-aromatizable androgen 5 alpha-dihydrotestosterone (DHT), into the lateral septum of adult male rats and measured plasma levels of LH and FSH by radioimmunoassay 2 days after implantation. Both testosterone and DHT significantly increased the plasma LH and FSH concentrations. Mean concentration of LH in control animals was 0.21 +/- 0.06 ng/ml, a figure that increased to 0.7 +/- 0.12 and 0.55 +/- 0.1 ng/ml after DHT or testosterone implantation respectively. Mean concentration of FSH in control animals was 1.5 +/- 0.3 ng/ml; this figure increased to 3 +/- 0.3 and 2.9 +/- 0.3 ng/ml after DHT or testosterone implantation. Neither plasma DHT (64.0 +/- 5.6 vs. 52 +/- 5 ng/100ml) nor plasma testosterone levels (4.1 +/- 0.38 vs. 3.3 +/- 0.18 ng/ml) were significantly affected by the implants. We conclude that androgens independently of conversion to estrogen acting in the lateral septum facilitates the release of LH and FSH.

Animals↗
PubMedDate not supplied

[Experience with the Du Pen epidural catheter in chronic cancer pain].

We evaluate the results obtained with the use of Du Pen's epidural catheter in a series of patients with chronic oncologic pain. There were 27 patients with neoplasms of different etiologies who received a total number of 30 catheters. Inclusion criteria were established. All patients received bolus of morphine chloride free of conservers. Follow-up controls were carried out at least every week and consisted on the evaluation the dosage efficacy, dose adjustments, catheter condition, physical activity, neurologic state, and requirements of adjuvant medication. The documented use of the 30 catheters implanted in this study lasted up to 1452 days with a mean of 48.5 days. There were no complications related to catheter insertion. However we observed complications related to the use of the catheter: reflow at the site of catheter implantation in 4 cases, infection of the external (one case) and internal (one case) catheter route without antibiotic resolution, and infection of the epidural space responding to antibiotherapy without catheter withdrawal in one patient. Twenty patients died. Mortality was not attributed to catheter complications in any case. The present study confirms that placement of the catheter is technically easy and provides an efficacious opiate analgesia with minimal complications.

Adult↗
PubMedDate not supplied

Plasma bupivacaine levels after pleural block: the effect of epinephrine after unilateral or bilateral bupivacaine administration.

BACKGROUND AND OBJECTIVES: To determine the effect of adding epinephrine (5 micrograms/ml) to bupivacaine during continuous spinal infusion and the effect of the administration of the same total dose of bupivacaine, in a bilateral or unilateral way, on its consequent plasma levels. METHODS: Sixteen cholecystectomized patients were studied prospectively. In ten patients with midline incision, bilateral pleural infusion (half total unilateral dose in each hemithorax) was administered, and in six patients with subcostal incision, unilateral pleural infusion. The unilateral group received a loading dose of 20 ml 0.375% bupivacaine immediately followed by an infusion at a rate of 6 ml/hour. Three patients randomly received epinephrine (5 micrograms/ml) added to bupivacaine, whereas the other three remaining patients did not receive it. The bilateral group received 10 ml 0.375% bupivacaine followed by an infusion at a rate of 3 ml/hour in each hemithorax. Five patients randomly received epinephrine; five others did not. The plasma levels of bupivacaine were determined at 5, 15, 30, and 60 minutes and at 6 and 18 hours. RESULTS: Plasma levels of bupivacaine were significantly lower (p less than 0.05) during the whole study in patients receiving epinephrine. For the same total dose, there were no statistical differences in the plasma levels of bupivacaine between unilateral and bilateral pleural groups. CONCLUSIONS: The addition of epinephrine (5 micrograms/ml) to a continuous pleural infusion of bupivacaine diminishes the plasma levels of the local anesthetic. For the same total dose of bupivacaine, there are no differences in the plasma levels obtained between unilateral and bilateral administration.

Adult↗
PubMedDate not supplied

[Comparison of thiopental and propofol in short-duration anesthesia].

Forty healthy females, 18 to 65 years, undergoing diagnostic or therapeutic uterine curettage were studied with the purpose of comparing anesthetic characteristics of thiopental and propofol as induction agents. They were randomly allocated in two groups: A propofol induction group (2.5 mg/kg), and a thiopental induction group (4-5 mg/kg). Fentanyl (2 micrograms/kg), was administered 2 minutes before anaesthesia, and N2O/O2 (66%/33%) by mask was maintained during surgery. Changes in systolic and diastolic BP were not significantly different in two groups. The HR decreased more significantly in the propofol group (20% vs 10%; p less than 0.005). Apnea was significantly greater in the propofol group, in term of incidence (50% vs 15%; p = 0.025), and duration (92 seg vs 17 seg; p = 0.20). The lapses of time to opening the eyes and response to a command were not significantly different, but the time to be able to seat was significantly lower in the propofol group (12 min vs 21 min; p = 0.0003). Anaesthesia was clinically satisfactory for most patients in both treatment groups.

Adolescent↗
PubMedDate not supplied

Long-term brachial plexus anesthesia using a subcutaneous implantable injection system. Case report.

BACKGROUND AND OBJECTIVES: Continuous brachial plexus anesthesia with local anesthesia has been used since 1946 for prolonged surgical procedures, in postoperative pain relief, and in sympathetic nerve block. The benefit or effectiveness of this technique in the relief of sympathetically maintained pain has yet to be established. METHODS: The following case report describes the placement of an axillary catheter connected to a port for the self-administration of local anesthesia to provide brachial plexus anesthesia in a 43-year-old woman suffering from sympathetically maintained pain. RESULTS: The administration of local anesthesia through this injection system resulted in complete pain relief without motor impairment of the arm. The device functioned for 118 days, making physical therapy easier. An infection occurred at the entry site, requiring the removal of the port. CONCLUSIONS: Controlled studies need to be done to establish the safety and efficacy of this form of therapy.

Adult↗
PubMedDate not supplied

[Influence of anesthetic technique in postoperative analgesia in thoracic surgery].

OBJECTIVE: To compare the intensity of postoperative pain after thoracotomy with 2 anesthetic techniques: 1) thoracic epidural block with bupivacaine administered before surgery (combined anesthesia with isoflurane) and 2) conventional balanced anesthesia with isoflurane and endovenous fentanyl. PATIENTS AND METHODS: Thirty patients scheduled for thoracotomy by lateral incision (T5-T6) were randomly divided into 2 groups of 15. Group A received 8 ml of 0.5% bupivacaine with adrenalin 1:200.000 30 min before start of surgery while group B received 8 ml saline solution through an epidural catheter inserted to T4-T8. Combined anesthesia (4 ml 0.5% bupivacaine through an epidural catheter 150 min after the first dose and isoflurane in 100% oxygen) was used in group A. Group B received balanced anesthesia with endovenous fentanyl 2.5 micrograms/kg and isoflurane in 100% oxygen. The difference in pain intensity during postoperative recovery was assessed by way of the following variables: number of boluses administered by epidural patient-controlled analgesia (bupivacaine 0.0625% and fentanyl 6 micrograms/ml); score on a visual analog scale of 10 at baseline and at 1, 3, 7, 11, 19 and 43 hours after surgery; and need for additional analgesia (diclofenac) during the 43 hours of study. Arterial gases were measured during the preoperative period and at 1, 3, 7, 19 and 43 hours after surgery. RESULTS: No significant differences in pain intensity measured on the visual analog scale, by the number of boluses per patients or by need for additional analgesia were found between the 2 groups. The total number of boluses administered and additional analgesic requirements were greater in the group receiving bupivacaine, although the difference was not significant (p = 0.095 and p = 0.056, respectively). Nor were there significant differences in pH and PaCO2 levels for the 2 groups. CONCLUSIONS: Analgesic efficacy after thoracotomy was similar for our 2 groups receiving either combined anesthesia (epidural bupivacaine at 0.5% and isoflurane) or balanced anesthesia with isoflurane and endovenous fentanyl.

Adult↗
PubMedDate not supplied

[Comparison between fentanyl and a fentanyl-bupivacaine combination using epidural PCA for postoperative analgesia after thoracotomy].

HYPOTHESIS: The association of opioids and local anesthetics for spinal analgesia appears to have a synergistic++ effect. OBJECTIVE: To compare the efficacy of fentanyl in comparison with combined fentanyl and bupivacaine at low concentrations in a thoracic epidural system of patient-controlled analgesia (PCA) following thoracotomy. PATIENTS AND METHODS: Twenty male patients scheduled for thoracotomy by postero-lateral (T5-T6) incision received analgesia after surgery through a thoracic (T4-T8) epidural catheter connected to a PCA pump (continuous infusion and boluses). They were randomly assigned to 2 groups as follows: group A (n = 10) received a baseline infusion of fentanyl 1 microgram/kg/h and bupivacaine 0.125% with boluses of 12.5 micrograms fentanyl and bupivacaine at 0.125%. The variables studied were: score on a visual analog scale (VAS) before treatment and at 12 and 24 h; the number of boluses administered through the PCA pump, forced vital capacity (FVC) and peak expiratory flow (PEF) before treatment and at 12 h. RESULTS: Analgesia was satisfactory in both groups, with no significant differences in VAS and number of boluses administered. Nor were there significant differences in lung function tests. One instance of respiratory depression was recorded in group A. CONCLUSIONS: The analgesic effect obtained with epidural fentanyl or fentanyl/bupivacaine is similar and adequate, and the association of fentanyl and bupivacaine can be considered safe.

Aged↗
PubMedDate not supplied

[Structure and function of an outpatient surgery unit].

In order for a surgical intervention to be performed in an outpatient regime three basic requisites must be met: adequate patient selection, appropriate type of surgery and adequate unit. These factors are important for the surgical procedure to be carried out with identical safety and success as that undertaken in an admitted patient. In out patient surgery, early psychomotor recovery and slight or lack of secondary effects are fundamental; thus, anesthetic technique is selected keeping these two points in mind as they determine the criteria for the release of the patients from hospital.

Adolescent↗