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Biomedical subjects

P Monedero

Publications and source records attributed to P Monedero.

15 recordsLinked to original sources
PubMed1997

Is management of anesthesia in achondroplastic dwarfs really a challenge?

STUDY OBJECTIVE: To review our eight-year anesthetic experience with achondroplastic patients. DESIGN: Retrospective study. SETTING: University hospital. PATIENTS: 15 achondroplastic patients who underwent 53 surgical procedures of orthopedic surgery between 1987 and 1994. INTERVENTIONS: Anesthetic technique, drugs, number of incidents, and complications in the intraoperative and postoperative period were recorded. MEASUREMENTS AND MAIN RESULTS: Adequate premedication before the transfer to the operating room was very useful to reduce anxiety and increase cooperation. Inhalation induction was well tolerated and allowed easy peripheral venous cannulation. Only one patient presented difficulties during intubation (on two occasions). In the other patients, we found small difficulties only during ventilation with a face mask, which was easily corrected by modifying the position of the patient and/or inserting an oropharyngeal airway. No adverse effect was identified for any particular anesthetic drug or technique used. CONCLUSIONS: Although the characteristic deformities of achondroplastic patients can impede the management of anesthesia, in our study we found no special difficulties. Airway complications did not occur. Thus, no specific optimal anesthetic regimen can be recommended.

Achondroplasia↗
PubMed1996

Combination of ondansetron and dexamethasone in the prophylaxis of postoperative nausea and vomiting.

We studied 100 ASA I-II females undergoing general anaesthesia for major gynaecological surgery, in a prospective, double-blind, placebo-controlled, randomized study. Patients received one of four regimens for the prevention of postoperative nausea and vomiting (PONV): ondansetron 4 mg (n = 25), dexamethasone 8 mg (n = 25), ondansetron with dexamethasone (4 mg and 8 mg, respectively, n = 25) or placebo (saline, n = 25) There were no differences in background factors or factors related to operation and anaesthesia, morphine consumption, pain or side effects between groups. The incidence of nausea and emetic episodes in the ondansetron with dexamethasone group was lower than in the placebo (P < 0.01), ondansetron (P < 0.05) and dexamethasone (P = 0.057) groups. There were no differences between ondansetron and dexamethasone, and both were more effective than placebo (P < 0.05 and P < 0.01, respectively). Dexamethasone appeared to be preferable in preventing nausea than emetic episodes. Fewer patients in the ondansetron with dexamethasone group needed antimetic rescue (P < 0.01 vs placebo and P < 0.05 vs ondansetron). We conclude that prophylactic administration of combined ondansetron and dexamethasone is effective in preventing PONV.

Adolescent↗
PubMed1995

[Reduction of the need for blood derivatives in liver transplantation using aprotinin].

OBJECTIVES: To evaluate the efficacy of aprotinin in reducing the need for blood products in orthotopic liver transplantation. PATIENTS AND METHODS: Blood product needs and coagulation test results were studied in 42 adults with cirrhosis of the liver who received orthotopic liver transplants. The first 16 liver transplants carried out without aprotinin (control group) were compared with the next 26 consecutive transplant patients who received aprotinin. Each of the first 9 received a loading dose of 2 million units that was followed by the infusion of half a million units per hour until the end of surgery. The next 17 received the same infusion dose at the same rate but no loading dose. RESULTS: Patients who received aprotinin required fewer transfusions of blood products (5.3 units of packed red blood cells as opposed to 13 units; 9 units of fresh frozen plasma versus 14.6 units; 1.7 units of platelets versus 4.2 units; and 3.8 units of cryoprecipitates versus 8.8 units). We observed a marked reduction of fibrinolysis (less increase in D dimers after removal of the liver when aprotinin was used. CONCLUSIONS: Prophylactic use of aprotinin during surgery has a beneficial effect on hemostatic mechanisms, reducing the need for blood products. A reduction in fibrinolysis seems to contribute to this effect.

Adult↗
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

[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

[Ambulatory pediatric anesthesia: preanesthetic evaluation, anesthetic techniques, and immediate postoperative care].

The advantages of pediatric out-patient surgery are: 1) greater psychological ease; 2) lower rate of infection; 3) less impact on patient habits, and 4) lower cost. Surgery must not involve organs, must have a low rate of complications, and be short. The preanesthetic interview should include clinical history and complementary examinations, information on anesthetic technique, perioperative recommendations and psychological preparation of parents and child. Detailed information reassures parents and improves collaboration; their presence during induction may be useful. At this time complete fasting is not recommended; although solids are not permitted, clear liquids should be taken up to 2-3 hours before anesthesia. In this way the child is less irritable and hypoglycemia and hypotension during inhalational induction are prevented. Low doses of midazolam and ketamine have been used for premedication, which though possibly useful, is not recommended because recovery may be prolonged. Halogenated anesthetics are very useful, with nitrous oxide providing an excellent complement. The potentially toxic effect of halothane on the liver does not keep this agent from being the most popular. Recovery is fast with any of the usual hypnotics (etomidate, propofol, thiopentone). Although thiopentone continues to be the hypnotic drug of reference, propofol's versatility is causing it to gain wider acceptance. The use of atracurium or vecuronium is justified if the dose is adjusted in keeping with type of surgery and duration. Intraoperative analgesics include meperidine, fentanyl and alfentanyl; morphine is not recommended. Should tracheal intubation be necessary, laryngeal edema may be avoided by gentle, cautious laryngoscopy, the use of a tube without a balloon, and 3 h of postanesthetic observation. A laryngeal mask may serve as an alternative to tracheal intubation. Local-regional anesthesia, excepting epidural and spinal anesthesia, offers a number of advantages: blockade of nociceptive stimuli, avoidance of opioid drugs, rapid and pleasant awakening (excellent for postoperative analgesia), and less need for postoperative analgesics. The postoperative complications seen most often are related to respiration or hypertension, making routine postanesthetic pulse oximetry a recommendation. The most frequently used analgesics are paracetamol, magnesium dipyrone, diclofenac, ketorolac, or codeine compounds. Although the incidence of nausea and vomiting is low in children, they are frequently a cause of hospitalization. Inappropriate postoperative care can increase the rate of admissions and medico-legal problems.(ABSTRACT TRUNCATED AT 400 WORDS)

Age Factors↗
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↗