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Biomedical subjects

S Mercadante

Publications and source records attributed to S Mercadante.

At least 127 records · Page 7Linked to original sources
PubMed1992

Home palliative care: results in 1991 versus 1988.

Home care is greatly expanding because of the savings it offers by avoiding unnecessary hospitalization and also because patients benefit from being in their own home environments. Since 1988, Societa Assistenza Malato Oncologico Terminale (SAMOT) has organized a pain relief and home palliative care unit for terminal cancer patients. Objectives, difficulties, protocols, and achievements of 4 years of experience were examined, and the findings of the various years were compared. Our results suggest that considerable progress has been made in home palliative care. There are still social and cultural difficulties to overcome, however.

Female↗
PubMed1991

The effect of N2O on the oxyhemoglobin dissociation curve is mediated by CO2.

In order to test whether the previously reported effect of N2O on the oxyhemoglobin dissociation curve (ODC) depends upon the presence of 2, 3 DPG or CO2, the blood of healthy subjects was balanced in microtonometers at 37 degrees C with gas mixtures containing N2O but CO2 depleted. Samples of the same blood were exposed to the above gases after incubation at 37 degrees C for 24 hours in order to deplete them of 2, 3 DPG. After a 10 minute tonometry, the hemoglobin saturation and the pH were measured. The pH was corrected into 7.4.P50 increased 5.7% in fresh blood and 5% in 2, 3 DPG depleted blood after samples exposure to N2O. No effect of N2O on P50 was found in samples exposed to gas without CO2. The authors conclude that the effect of N2O on the ODC is mediated by CO2.

2,3-Diphosphoglycerate↗
PubMed1990

[Continuous infusion peridural analgesia in labor].

A technique of continuous infusion epidural anesthesia was used during labour in 933 patients divided into three groups according to age: Group A (14-18 years old), Group B (19-35 years old) and Group C (greater than 35 years old). Infusion was carried out using the following system: a PVC pressurized bag containing 0.3% marcain connected to 2 flow regulators which ensured a flow of 6 ml/h. During the dilatation phase, 85% of patients received sufficient analgesia, whereas 15% required extra boluses. During the expulsive phase 80% of patients received adequate analgesia of the perineal plane, 12% received an extra bolus of marcain 0.3% and local anesthesia was performed in 8% to allow infiltration. Instruments were required in 5.6% of patients in Group A, 11.3% in Group B and 7.4% in Group C. The incidence of Caesarian section was 5.6% in Group A, 9% in Group B and 14.8% in Group C. No maternal complication was observed. Epidural anesthesia via continuous infusion was therefore shown to be an efficacious and safe method for ensuring analgesia during labour.

Adolescent↗
PubMed1988

Effects of halothane, enflurane, and nitrous oxide on oxyhemoglobin affinity.

To test whether anesthetics alter hemoglobin O2 affinity, venous blood was sampled from 27 healthy subjects before and during general anesthesia for appendectomy with halothane, enflurane, or nitrous oxide anesthesia. 0.110-ml aliquots of blood were equilibrated in microtonometers at 37 degrees C with known PO2 levels in gases containing 0%, 0.5%, 1%, 2%, or 3% halothane, 0%, 1%, 2%, 3%, or 4% enflurane, or 60% N2O. pH was then measured and PO2 corrected to pH = 7.4. Saturation was determined spectrophotometrically (Radiometer OSM-2). P50 computed from this PO2 and measured saturation was increased 5% (P less than 0.01) when blood was tonometered with N2O, but not in blood samples taken during N2O anesthesia and then equilibrated without N2O. Halothane and enflurane had no effect. 2,3 DPG was not affected by any agent. The authors conclude that inhalational agents in use today do not cause the oxygen dissociation curve to change in a way which might jeopardize the patient's oxygenation.

Adolescent↗
PubMed1987

Hemodynamics, prolactin and catecholamine levels during hemorrhagic shock in dogs pretreated with a prolactin inhibitor (bromocriptine).

Bromocriptin, a dopaminomimetic drug, causing inhibition of prolactin secretion, was used in experiments on haemorrhagic shock in dogs. 5 dogs were treated with bromocriptine (0.4 mg.day-1) for two days; a further 5 dogs were used as control animals. 30% of the blood volume was drawn from each dog. Mean arterial blood pressure, heart rate, central venous pressure, acid-base status, prolactin, GH and catecholamine levels were checked before blood letting and monitored until 1 hour after blood letting. Animals treated with bromocriptine showed a significant decrease of the mean arterial blood pressure and of the prolactin rate and a significant increase of catecholamine levels. Control animals, instead, showed a significant increase of the prolactine and catecholamine rates. The results obtained suggest that bromocriptine can constitute an additional hypotensive factor in subjects with acute haemorrhage. A considerable amount of research work previously carried out has shown a close correlation between stress and hyper-prolactinemia. The increase of prolactinemia and the effects of bromocriptine on this hormone during surgical stress is particularly interesting due to its possible implications (Lanza V. et coll., 1983). In previous experiments involving animals it was found that Prolactin exerts positive chronotropic and hypertensive effects (Horrobin D.F., 1977) whilst bromocriptine is a potent agonist of D2 dopaminergic receptors (Thorner M.O. et coll., 1980). Dopamine was found to be particularly useful in the clinical treatment of shock thus suggesting an involvement of peripheral D2 receptors. On the basis of these observations we have considered it worthwhile to investigate the haemodynamic effects of bromocriptine in haemorrhagic shock.

Animals↗
PubMed1986

[Neuroendocrine response to anesthesia with isoflurane].

The effects during surgery of a new halogenated volatile anaesthetic, isoflurane, on the hypothalamo-hypophyseal-thyroid-suprarenal axis were studied. In fact, it was important to prove whether this new halogenated anaesthetic would provide better protection, for the patient, from surgery and anaesthetic stress compared with other anaesthetic agents in use. The study was carried out in 16 young class ASA I patients who were to undergo appendicectomy. Before and during operation, blood was taken to measure ACTH, cortisol, TSH, T3, T4 and PRL plasma levels. A remarkable increase of PRL, cortisol and T4 plasmatic rate was found, especially at the end of the operation. It was concluded that isoflurane, just like enflurane, did not prevent the increase of PRL, cortisol and T4 that usually takes place during surgery.

Adolescent↗
PubMed1984

Influence of cerebral spinal fluid on the affinity of human red cells for oxygen.

The oxygen affinity of washed red cells suspended in their own plasma or in CSF has been studied to demonstrate a possible effect of CSF on the oxygen affinity of human haemoglobin. The CSF was found to reduce the oxygen affinity of haemoglobin significatively, and this was not imputable to the action of pH, PCO2, temperature, 2,3DPG A hypothesis to explain the data found and their clinical interest towards the regulation of brain oxygenation was formulated considering the Monod-Wyman-Changeux model and the effect of solutions on proteins.

Adult↗
PubMed1984

A visual representation of a model for monitoring the state of oxygenation in the critically ill patients. Description and clinical validation.

The authors propose a new circular diagram for monitoring the oxygenation status of critically ill patients. This diagram contains some well known parameters; other ones are suggested to evaluate the pulmonary function and the capability of blood oxygenation. The calculation and a "BASIC" program are provided to use the diagram. This method offers a fast and easy monitoring of oxygenation status by a very small arterious and central venous blood sample.

Humans↗
PubMedDate not supplied

Celiac plexus block: a reappraisal.

BACKGROUND AND OBJECTIVES: The neurolytic celiac plexus block is an established, well-developed procedure and the most widely applicable of all the neurolytic pain blocks. It optimizes palliative treatment for cancer of the upper abdominal viscera. Several techniques have been proposed in an attempt to increase success rates, reduce morbidity, and enhance technical accuracy. However, the assessment of the results and effectiveness of the block have been controversial. METHODS: A survey was made of pertinent English language literature on the anatomic and technical problems, indications, advantages, complications, and outcomes related to the neurolytic celiac plexus block as well as the neurolytic solutions and radiologic guidance used. RESULTS: The successful relief of the pain of pancreatic cancer and other abdominal malignancies can be expected in 85% and 73% of patients, respectively. Following the block, many patients can be weaned from opioids or at least have their dose reduced. The half-life of the celiac plexus block seems to be more than 4 weeks. The probability of patients remaining completely pain-free diminishes with increases survival time. The technique selected should be appropriate to the available and the extent of malignancy, since the analgesic results seem to be independent of the principal techniques used. Serious complications are extremely rare. However, critical analysis revealed major deficiencies in all of the reports reviewed. CONCLUSION: Neurolytic celiac plexus block alone is capable of providing complete pain relief until death in a few cases and, therefore, should be considered as an adjuvant treatment in the analgesic strategy. Combination palliative therapy is necessary in most cases. Failure of the block may be attributed to tumor metastasizing beyond the nerves that conduct pain via the celiac plexus and the component nerves that form it. Concomitant pain of somatic origin (frequently observed in upper gastrointestinal cancer because of significant peritoneal involvement) requires other therapeutic measures.

Animals↗
PubMedDate not supplied

Neuraxial techniques for cancer pain: an opinion about unresolved therapeutic dilemmas.

BACKGROUND AND OBJECTIVES: Epidural and intrathecal techniques are well established for minimizing cancer pain. However, several issues remain unresolved. METHODS: A review of studies published in the last 10 years regarding neuraxial techniques in cancer pain management was made. The following issues were assessed: appropriate indications; techniques and delivery systems; conversion from systemic to spinal administration; route and modes of administration; choice of opioids, analgesic response and adverse effects of opioids; use of local anesthetics; use of adjuvants; technical complications; and possible problems only recognized at home. RESULTS: Indications for the use of neuraxial opioids include patients treated with systemic opioids who received effective pain relief but with unacceptable side effects or unsuccessful treatment despite escalating doses with sequential, strong opioid drug trials. The choice of exteriorized or implanted delivery systems is based on different clinical considerations. The use of externalized, tunnelled intrathecal catheters has not been proven to be associated with higher rates of complications, and they may be easier to place and use at home in debilitated patients late in the course of their disease. Intrathecal administration has a lower incidence of catheter occlusion, lower malfunction rate, lower dose and volume requirements, and more effective pain control. Advantages of continuous infusion techniques are more evident when using local anesthetics, because intermittent administration of bupivacaine often results in motor paralysis and hemodynamic instability. Morphine appears to be the opioid of choice, and an epidural dose of 10% of the systemic dose is often used. Bupivacaine-induced adverse effects have been reported infrequently with bupivacaine doses less than 30-60 mg/d. Adjuvant drugs, such as clonidine and neostigmine, may further improve analgesia. Varied ranges of technical complication rates have been reported in the literature, with most being associated with epidural catheters. CONCLUSIONS: A subcutaneous tunnelling and fixation of the catheter, bacterial filters, minimum changes of tubings, weekly exit site care, site protection, and monitoring for any signs of infection are suggested for advanced cancer patients. Areas still needing clarification include the optimum use of spinal adjuvants, the appropriate spinal morphine-bupivacaine ratio, methods to improve spinal opioid responsiveness, and long-term catheter management during home-care programs.

Analgesia↗
PubMedDate not supplied

[Importance of an outpatient record in obstetric anesthesia].

A computerised record was used to collect data following an anesthesiological check-up of pregnant women at approximately 30 weeks of pregnancy. The record was input onto a portable PC in the anesthesia outpatient clinic, memorized on disk (3.5") and then transferred onto a PC network (one PC for each operating theatre) for "real time" consultation of each patient's data. All pregnant women attending the antenatal clinico were also given a folder illustrating epidural anesthetic techniques. Seven hundred and nine outpatient visits have been performed over the past two years with a 62% utilisation ratio. The collection of data using a computerised system allows a rapid and efficacious system of communication to be set up among the membranes of the anesthesiological team, thus encouraging the use of epidural techniques during labour. The distribution of the folder also facilitated the task of the anesthetist who found that pregnant women visiting the anesthesia clinic were already familiar with the epidural technique.

Anesthesia, Epidural↗